drm2/i915/intel_pm.c

/*
 * Copyright © 2012 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 * Authors:
 *    Eugeni Dodonov <eugeni.dodonov@intel.com>
 *
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <dev/drm2/drmP.h>
#include <dev/drm2/drm.h>
#include <dev/drm2/i915/i915_drm.h>
#include <dev/drm2/i915/i915_drv.h>
#include <dev/drm2/i915/intel_drv.h>
#include <sys/kdb.h>

static struct drm_i915_private *i915_mch_dev;
/*
 * Lock protecting IPS related data structures
 *   - i915_mch_dev
 *   - dev_priv->max_delay
 *   - dev_priv->min_delay
 *   - dev_priv->fmax
 *   - dev_priv->gpu_busy
 */
static struct mtx mchdev_lock;
MTX_SYSINIT(mchdev, &mchdev_lock, "mchdev", MTX_DEF);

/* FBC, or Frame Buffer Compression, is a technique employed to compress the
 * framebuffer contents in-memory, aiming at reducing the required bandwidth
 * during in-memory transfers and, therefore, reduce the power packet.
 *
 * The benefits of FBC are mostly visible with solid backgrounds and
 * variation-less patterns.
 *
 * FBC-related functionality can be enabled by the means of the
 * i915.i915_enable_fbc parameter
 */

static void i8xx_disable_fbc(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 fbc_ctl;

        /* Disable compression */
        fbc_ctl = I915_READ(FBC_CONTROL);
        if ((fbc_ctl & FBC_CTL_EN) == 0)
                return;

        fbc_ctl &= ~FBC_CTL_EN;
        I915_WRITE(FBC_CONTROL, fbc_ctl);

        /* Wait for compressing bit to clear */
        if (wait_for((I915_READ(FBC_STATUS) & FBC_STAT_COMPRESSING) == 0, 10)) {
                DRM_DEBUG_KMS("FBC idle timed out\n");
                return;
        }

        DRM_DEBUG_KMS("disabled FBC\n");
}

static void i8xx_enable_fbc(struct drm_crtc *crtc, unsigned long interval)
{
        struct drm_device *dev = crtc->dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct drm_framebuffer *fb = crtc->fb;
        struct intel_framebuffer *intel_fb = to_intel_framebuffer(fb);
        struct drm_i915_gem_object *obj = intel_fb->obj;
        struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
        int cfb_pitch;
        int plane, i;
        u32 fbc_ctl, fbc_ctl2;

        cfb_pitch = dev_priv->cfb_size / FBC_LL_SIZE;
        if (fb->pitches[0] < cfb_pitch)
                cfb_pitch = fb->pitches[0];

        /* FBC_CTL wants 64B units */
        cfb_pitch = (cfb_pitch / 64) - 1;
        plane = intel_crtc->plane == 0 ? FBC_CTL_PLANEA : FBC_CTL_PLANEB;

        /* Clear old tags */
        for (i = 0; i < (FBC_LL_SIZE / 32) + 1; i++)
                I915_WRITE(FBC_TAG + (i * 4), 0);

        /* Set it up... */
        fbc_ctl2 = FBC_CTL_FENCE_DBL | FBC_CTL_IDLE_IMM | FBC_CTL_CPU_FENCE;
        fbc_ctl2 |= plane;
        I915_WRITE(FBC_CONTROL2, fbc_ctl2);
        I915_WRITE(FBC_FENCE_OFF, crtc->y);

        /* enable it... */
        fbc_ctl = FBC_CTL_EN | FBC_CTL_PERIODIC;
        if (IS_I945GM(dev))
                fbc_ctl |= FBC_CTL_C3_IDLE; /* 945 needs special SR handling */
        fbc_ctl |= (cfb_pitch & 0xff) << FBC_CTL_STRIDE_SHIFT;
        fbc_ctl |= (interval & 0x2fff) << FBC_CTL_INTERVAL_SHIFT;
        fbc_ctl |= obj->fence_reg;
        I915_WRITE(FBC_CONTROL, fbc_ctl);

        DRM_DEBUG_KMS("enabled FBC, pitch %d, yoff %d, plane %d, ",
                      cfb_pitch, crtc->y, intel_crtc->plane);
}

static bool i8xx_fbc_enabled(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        return I915_READ(FBC_CONTROL) & FBC_CTL_EN;
}

static void g4x_enable_fbc(struct drm_crtc *crtc, unsigned long interval)
{
        struct drm_device *dev = crtc->dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct drm_framebuffer *fb = crtc->fb;
        struct intel_framebuffer *intel_fb = to_intel_framebuffer(fb);
        struct drm_i915_gem_object *obj = intel_fb->obj;
        struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
        int plane = intel_crtc->plane == 0 ? DPFC_CTL_PLANEA : DPFC_CTL_PLANEB;
        unsigned long stall_watermark = 200;
        u32 dpfc_ctl;

        dpfc_ctl = plane | DPFC_SR_EN | DPFC_CTL_LIMIT_1X;
        dpfc_ctl |= DPFC_CTL_FENCE_EN | obj->fence_reg;
        I915_WRITE(DPFC_CHICKEN, DPFC_HT_MODIFY);

        I915_WRITE(DPFC_RECOMP_CTL, DPFC_RECOMP_STALL_EN |
                   (stall_watermark << DPFC_RECOMP_STALL_WM_SHIFT) |
                   (interval << DPFC_RECOMP_TIMER_COUNT_SHIFT));
        I915_WRITE(DPFC_FENCE_YOFF, crtc->y);

        /* enable it... */
        I915_WRITE(DPFC_CONTROL, I915_READ(DPFC_CONTROL) | DPFC_CTL_EN);

        DRM_DEBUG_KMS("enabled fbc on plane %d\n", intel_crtc->plane);
}

static void g4x_disable_fbc(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 dpfc_ctl;

        /* Disable compression */
        dpfc_ctl = I915_READ(DPFC_CONTROL);
        if (dpfc_ctl & DPFC_CTL_EN) {
                dpfc_ctl &= ~DPFC_CTL_EN;
                I915_WRITE(DPFC_CONTROL, dpfc_ctl);

                DRM_DEBUG_KMS("disabled FBC\n");
        }
}

static bool g4x_fbc_enabled(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        return I915_READ(DPFC_CONTROL) & DPFC_CTL_EN;
}

static void sandybridge_blit_fbc_update(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 blt_ecoskpd;

        /* Make sure blitter notifies FBC of writes */
        gen6_gt_force_wake_get(dev_priv);
        blt_ecoskpd = I915_READ(GEN6_BLITTER_ECOSKPD);
        blt_ecoskpd |= GEN6_BLITTER_FBC_NOTIFY <<
                GEN6_BLITTER_LOCK_SHIFT;
        I915_WRITE(GEN6_BLITTER_ECOSKPD, blt_ecoskpd);
        blt_ecoskpd |= GEN6_BLITTER_FBC_NOTIFY;
        I915_WRITE(GEN6_BLITTER_ECOSKPD, blt_ecoskpd);
        blt_ecoskpd &= ~(GEN6_BLITTER_FBC_NOTIFY <<
                         GEN6_BLITTER_LOCK_SHIFT);
        I915_WRITE(GEN6_BLITTER_ECOSKPD, blt_ecoskpd);
        POSTING_READ(GEN6_BLITTER_ECOSKPD);
        gen6_gt_force_wake_put(dev_priv);
}

static void ironlake_enable_fbc(struct drm_crtc *crtc, unsigned long interval)
{
        struct drm_device *dev = crtc->dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct drm_framebuffer *fb = crtc->fb;
        struct intel_framebuffer *intel_fb = to_intel_framebuffer(fb);
        struct drm_i915_gem_object *obj = intel_fb->obj;
        struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
        int plane = intel_crtc->plane == 0 ? DPFC_CTL_PLANEA : DPFC_CTL_PLANEB;
        unsigned long stall_watermark = 200;
        u32 dpfc_ctl;

        dpfc_ctl = I915_READ(ILK_DPFC_CONTROL);
        dpfc_ctl &= DPFC_RESERVED;
        dpfc_ctl |= (plane | DPFC_CTL_LIMIT_1X);
        /* Set persistent mode for front-buffer rendering, ala X. */
        dpfc_ctl |= DPFC_CTL_PERSISTENT_MODE;
        dpfc_ctl |= (DPFC_CTL_FENCE_EN | obj->fence_reg);
        I915_WRITE(ILK_DPFC_CHICKEN, DPFC_HT_MODIFY);

        I915_WRITE(ILK_DPFC_RECOMP_CTL, DPFC_RECOMP_STALL_EN |
                   (stall_watermark << DPFC_RECOMP_STALL_WM_SHIFT) |
                   (interval << DPFC_RECOMP_TIMER_COUNT_SHIFT));
        I915_WRITE(ILK_DPFC_FENCE_YOFF, crtc->y);
        I915_WRITE(ILK_FBC_RT_BASE, obj->gtt_offset | ILK_FBC_RT_VALID);
        /* enable it... */
        I915_WRITE(ILK_DPFC_CONTROL, dpfc_ctl | DPFC_CTL_EN);

        if (IS_GEN6(dev)) {
                I915_WRITE(SNB_DPFC_CTL_SA,
                           SNB_CPU_FENCE_ENABLE | obj->fence_reg);
                I915_WRITE(DPFC_CPU_FENCE_OFFSET, crtc->y);
                sandybridge_blit_fbc_update(dev);
        }

        DRM_DEBUG_KMS("enabled fbc on plane %d\n", intel_crtc->plane);
}

static void ironlake_disable_fbc(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 dpfc_ctl;

        /* Disable compression */
        dpfc_ctl = I915_READ(ILK_DPFC_CONTROL);
        if (dpfc_ctl & DPFC_CTL_EN) {
                dpfc_ctl &= ~DPFC_CTL_EN;
                I915_WRITE(ILK_DPFC_CONTROL, dpfc_ctl);

                DRM_DEBUG_KMS("disabled FBC\n");
        }
}

static bool ironlake_fbc_enabled(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        return I915_READ(ILK_DPFC_CONTROL) & DPFC_CTL_EN;
}

bool intel_fbc_enabled(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        if (!dev_priv->display.fbc_enabled)
                return false;

        return dev_priv->display.fbc_enabled(dev);
}

static void intel_fbc_work_fn(void *arg, int pending)
{
        struct intel_fbc_work *work = arg;
        struct drm_device *dev = work->crtc->dev;
        struct drm_i915_private *dev_priv = dev->dev_private;

        DRM_LOCK(dev);
        if (work == dev_priv->fbc_work) {
                /* Double check that we haven't switched fb without cancelling
                 * the prior work.
                 */
                if (work->crtc->fb == work->fb) {
                        dev_priv->display.enable_fbc(work->crtc,
                                                     work->interval);

                        dev_priv->cfb_plane = to_intel_crtc(work->crtc)->plane;
                        dev_priv->cfb_fb = work->crtc->fb->base.id;
                        dev_priv->cfb_y = work->crtc->y;
                }

                dev_priv->fbc_work = NULL;
        }
        DRM_UNLOCK(dev);

        free(work, DRM_MEM_KMS);
}

static void intel_cancel_fbc_work(struct drm_i915_private *dev_priv)
{
        u_int pending;

        if (dev_priv->fbc_work == NULL)
                return;

        DRM_DEBUG_KMS("cancelling pending FBC enable\n");

        /* Synchronisation is provided by struct_mutex and checking of
         * dev_priv->fbc_work, so we can perform the cancellation
         * entirely asynchronously.
         */
        if (taskqueue_cancel_timeout(dev_priv->tq, &dev_priv->fbc_work->task,
            &pending) == 0)
                /* tasklet was killed before being run, clean up */
                free(dev_priv->fbc_work, DRM_MEM_KMS);

        /* Mark the work as no longer wanted so that if it does
         * wake-up (because the work was already running and waiting
         * for our mutex), it will discover that is no longer
         * necessary to run.
         */
        dev_priv->fbc_work = NULL;
}

void intel_enable_fbc(struct drm_crtc *crtc, unsigned long interval)
{
        struct intel_fbc_work *work;
        struct drm_device *dev = crtc->dev;
        struct drm_i915_private *dev_priv = dev->dev_private;

        if (!dev_priv->display.enable_fbc)
                return;

        intel_cancel_fbc_work(dev_priv);

        work = malloc(sizeof(*work), DRM_MEM_KMS, M_WAITOK | M_ZERO);

        work->crtc = crtc;
        work->fb = crtc->fb;
        work->interval = interval;
        TIMEOUT_TASK_INIT(dev_priv->tq, &work->task, 0, intel_fbc_work_fn,
            work);

        dev_priv->fbc_work = work;

        DRM_DEBUG_KMS("scheduling delayed FBC enable\n");

        /* Delay the actual enabling to let pageflipping cease and the
         * display to settle before starting the compression. Note that
         * this delay also serves a second purpose: it allows for a
         * vblank to pass after disabling the FBC before we attempt
         * to modify the control registers.
         *
         * A more complicated solution would involve tracking vblanks
         * following the termination of the page-flipping sequence
         * and indeed performing the enable as a co-routine and not
         * waiting synchronously upon the vblank.
         */
        taskqueue_enqueue_timeout(dev_priv->tq, &work->task,
            msecs_to_jiffies(50));
}

void intel_disable_fbc(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        intel_cancel_fbc_work(dev_priv);

        if (!dev_priv->display.disable_fbc)
                return;

        dev_priv->display.disable_fbc(dev);
        dev_priv->cfb_plane = -1;
}

/**
 * intel_update_fbc - enable/disable FBC as needed
 * @dev: the drm_device
 *
 * Set up the framebuffer compression hardware at mode set time.  We
 * enable it if possible:
 *   - plane A only (on pre-965)
 *   - no pixel mulitply/line duplication
 *   - no alpha buffer discard
 *   - no dual wide
 *   - framebuffer <= 2048 in width, 1536 in height
 *
 * We can't assume that any compression will take place (worst case),
 * so the compressed buffer has to be the same size as the uncompressed
 * one.  It also must reside (along with the line length buffer) in
 * stolen memory.
 *
 * We need to enable/disable FBC on a global basis.
 */
void intel_update_fbc(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct drm_crtc *crtc = NULL, *tmp_crtc;
        struct intel_crtc *intel_crtc;
        struct drm_framebuffer *fb;
        struct intel_framebuffer *intel_fb;
        struct drm_i915_gem_object *obj;
        int enable_fbc;

        DRM_DEBUG_KMS("\n");

        if (!i915_powersave)
                return;

        if (!I915_HAS_FBC(dev))
                return;

        /*
         * If FBC is already on, we just have to verify that we can
         * keep it that way...
         * Need to disable if:
         *   - more than one pipe is active
         *   - changing FBC params (stride, fence, mode)
         *   - new fb is too large to fit in compressed buffer
         *   - going to an unsupported config (interlace, pixel multiply, etc.)
         */
        list_for_each_entry(tmp_crtc, &dev->mode_config.crtc_list, head) {
                if (tmp_crtc->enabled && tmp_crtc->fb) {
                        if (crtc) {
                                DRM_DEBUG_KMS("more than one pipe active, disabling compression\n");
                                dev_priv->no_fbc_reason = FBC_MULTIPLE_PIPES;
                                goto out_disable;
                        }
                        crtc = tmp_crtc;
                }
        }

        if (!crtc || crtc->fb == NULL) {
                DRM_DEBUG_KMS("no output, disabling\n");
                dev_priv->no_fbc_reason = FBC_NO_OUTPUT;
                goto out_disable;
        }

        intel_crtc = to_intel_crtc(crtc);
        fb = crtc->fb;
        intel_fb = to_intel_framebuffer(fb);
        obj = intel_fb->obj;

        enable_fbc = i915_enable_fbc;
        if (enable_fbc < 0) {
                DRM_DEBUG_KMS("fbc set to per-chip default\n");
                enable_fbc = 1;
                if (INTEL_INFO(dev)->gen <= 6)
                        enable_fbc = 0;
        }
        if (!enable_fbc) {
                DRM_DEBUG_KMS("fbc disabled per module param\n");
                dev_priv->no_fbc_reason = FBC_MODULE_PARAM;
                goto out_disable;
        }
        if (intel_fb->obj->base.size > dev_priv->cfb_size) {
                DRM_DEBUG_KMS("framebuffer too large, disabling "
                              "compression\n");
                dev_priv->no_fbc_reason = FBC_STOLEN_TOO_SMALL;
                goto out_disable;
        }
        if ((crtc->mode.flags & DRM_MODE_FLAG_INTERLACE) ||
            (crtc->mode.flags & DRM_MODE_FLAG_DBLSCAN)) {
                DRM_DEBUG_KMS("mode incompatible with compression, "
                              "disabling\n");
                dev_priv->no_fbc_reason = FBC_UNSUPPORTED_MODE;
                goto out_disable;
        }
        if ((crtc->mode.hdisplay > 2048) ||
            (crtc->mode.vdisplay > 1536)) {
                DRM_DEBUG_KMS("mode too large for compression, disabling\n");
                dev_priv->no_fbc_reason = FBC_MODE_TOO_LARGE;
                goto out_disable;
        }
        if ((IS_I915GM(dev) || IS_I945GM(dev)) && intel_crtc->plane != 0) {
                DRM_DEBUG_KMS("plane not 0, disabling compression\n");
                dev_priv->no_fbc_reason = FBC_BAD_PLANE;
                goto out_disable;
        }

        /* The use of a CPU fence is mandatory in order to detect writes
         * by the CPU to the scanout and trigger updates to the FBC.
         */
        if (obj->tiling_mode != I915_TILING_X ||
            obj->fence_reg == I915_FENCE_REG_NONE) {
                DRM_DEBUG_KMS("framebuffer not tiled or fenced, disabling compression\n");
                dev_priv->no_fbc_reason = FBC_NOT_TILED;
                goto out_disable;
        }

        /* If the kernel debugger is active, always disable compression */
        if (kdb_active)
                goto out_disable;

        /* If the scanout has not changed, don't modify the FBC settings.
         * Note that we make the fundamental assumption that the fb->obj
         * cannot be unpinned (and have its GTT offset and fence revoked)
         * without first being decoupled from the scanout and FBC disabled.
         */
        if (dev_priv->cfb_plane == intel_crtc->plane &&
            dev_priv->cfb_fb == fb->base.id &&
            dev_priv->cfb_y == crtc->y)
                return;

        if (intel_fbc_enabled(dev)) {
                /* We update FBC along two paths, after changing fb/crtc
                 * configuration (modeswitching) and after page-flipping
                 * finishes. For the latter, we know that not only did
                 * we disable the FBC at the start of the page-flip
                 * sequence, but also more than one vblank has passed.
                 *
                 * For the former case of modeswitching, it is possible
                 * to switch between two FBC valid configurations
                 * instantaneously so we do need to disable the FBC
                 * before we can modify its control registers. We also
                 * have to wait for the next vblank for that to take
                 * effect. However, since we delay enabling FBC we can
                 * assume that a vblank has passed since disabling and
                 * that we can safely alter the registers in the deferred
                 * callback.
                 *
                 * In the scenario that we go from a valid to invalid
                 * and then back to valid FBC configuration we have
                 * no strict enforcement that a vblank occurred since
                 * disabling the FBC. However, along all current pipe
                 * disabling paths we do need to wait for a vblank at
                 * some point. And we wait before enabling FBC anyway.
                 */
                DRM_DEBUG_KMS("disabling active FBC for update\n");
                intel_disable_fbc(dev);
        }

        intel_enable_fbc(crtc, 500);
        return;

out_disable:
        /* Multiple disables should be harmless */
        if (intel_fbc_enabled(dev)) {
                DRM_DEBUG_KMS("unsupported config, disabling FBC\n");
                intel_disable_fbc(dev);
        }
}

static void i915_pineview_get_mem_freq(struct drm_device *dev)
{
        drm_i915_private_t *dev_priv = dev->dev_private;
        u32 tmp;

        tmp = I915_READ(CLKCFG);

        switch (tmp & CLKCFG_FSB_MASK) {
        case CLKCFG_FSB_533:
                dev_priv->fsb_freq = 533; /* 133*4 */
                break;
        case CLKCFG_FSB_800:
                dev_priv->fsb_freq = 800; /* 200*4 */
                break;
        case CLKCFG_FSB_667:
                dev_priv->fsb_freq =  667; /* 167*4 */
                break;
        case CLKCFG_FSB_400:
                dev_priv->fsb_freq = 400; /* 100*4 */
                break;
        }

        switch (tmp & CLKCFG_MEM_MASK) {
        case CLKCFG_MEM_533:
                dev_priv->mem_freq = 533;
                break;
        case CLKCFG_MEM_667:
                dev_priv->mem_freq = 667;
                break;
        case CLKCFG_MEM_800:
                dev_priv->mem_freq = 800;
                break;
        }

        /* detect pineview DDR3 setting */
        tmp = I915_READ(CSHRDDR3CTL);
        dev_priv->is_ddr3 = (tmp & CSHRDDR3CTL_DDR3) ? 1 : 0;
}

static void i915_ironlake_get_mem_freq(struct drm_device *dev)
{
        drm_i915_private_t *dev_priv = dev->dev_private;
        u16 ddrpll, csipll;

        ddrpll = I915_READ16(DDRMPLL1);
        csipll = I915_READ16(CSIPLL0);

        switch (ddrpll & 0xff) {
        case 0xc:
                dev_priv->mem_freq = 800;
                break;
        case 0x10:
                dev_priv->mem_freq = 1066;
                break;
        case 0x14:
                dev_priv->mem_freq = 1333;
                break;
        case 0x18:
                dev_priv->mem_freq = 1600;
                break;
        default:
                DRM_DEBUG("unknown memory frequency 0x%02x\n",
                                 ddrpll & 0xff);
                dev_priv->mem_freq = 0;
                break;
        }

        dev_priv->r_t = dev_priv->mem_freq;

        switch (csipll & 0x3ff) {
        case 0x00c:
                dev_priv->fsb_freq = 3200;
                break;
        case 0x00e:
                dev_priv->fsb_freq = 3733;
                break;
        case 0x010:
                dev_priv->fsb_freq = 4266;
                break;
        case 0x012:
                dev_priv->fsb_freq = 4800;
                break;
        case 0x014:
                dev_priv->fsb_freq = 5333;
                break;
        case 0x016:
                dev_priv->fsb_freq = 5866;
                break;
        case 0x018:
                dev_priv->fsb_freq = 6400;
                break;
        default:
                DRM_DEBUG("unknown fsb frequency 0x%04x\n",
                                 csipll & 0x3ff);
                dev_priv->fsb_freq = 0;
                break;
        }

        if (dev_priv->fsb_freq == 3200) {
                dev_priv->c_m = 0;
        } else if (dev_priv->fsb_freq > 3200 && dev_priv->fsb_freq <= 4800) {
                dev_priv->c_m = 1;
        } else {
                dev_priv->c_m = 2;
        }
}

static const struct cxsr_latency cxsr_latency_table[] = {
        {1, 0, 800, 400, 3382, 33382, 3983, 33983},    /* DDR2-400 SC */
        {1, 0, 800, 667, 3354, 33354, 3807, 33807},    /* DDR2-667 SC */
        {1, 0, 800, 800, 3347, 33347, 3763, 33763},    /* DDR2-800 SC */
        {1, 1, 800, 667, 6420, 36420, 6873, 36873},    /* DDR3-667 SC */
        {1, 1, 800, 800, 5902, 35902, 6318, 36318},    /* DDR3-800 SC */

        {1, 0, 667, 400, 3400, 33400, 4021, 34021},    /* DDR2-400 SC */
        {1, 0, 667, 667, 3372, 33372, 3845, 33845},    /* DDR2-667 SC */
        {1, 0, 667, 800, 3386, 33386, 3822, 33822},    /* DDR2-800 SC */
        {1, 1, 667, 667, 6438, 36438, 6911, 36911},    /* DDR3-667 SC */
        {1, 1, 667, 800, 5941, 35941, 6377, 36377},    /* DDR3-800 SC */

        {1, 0, 400, 400, 3472, 33472, 4173, 34173},    /* DDR2-400 SC */
        {1, 0, 400, 667, 3443, 33443, 3996, 33996},    /* DDR2-667 SC */
        {1, 0, 400, 800, 3430, 33430, 3946, 33946},    /* DDR2-800 SC */
        {1, 1, 400, 667, 6509, 36509, 7062, 37062},    /* DDR3-667 SC */
        {1, 1, 400, 800, 5985, 35985, 6501, 36501},    /* DDR3-800 SC */

        {0, 0, 800, 400, 3438, 33438, 4065, 34065},    /* DDR2-400 SC */
        {0, 0, 800, 667, 3410, 33410, 3889, 33889},    /* DDR2-667 SC */
        {0, 0, 800, 800, 3403, 33403, 3845, 33845},    /* DDR2-800 SC */
        {0, 1, 800, 667, 6476, 36476, 6955, 36955},    /* DDR3-667 SC */
        {0, 1, 800, 800, 5958, 35958, 6400, 36400},    /* DDR3-800 SC */

        {0, 0, 667, 400, 3456, 33456, 4103, 34106},    /* DDR2-400 SC */
        {0, 0, 667, 667, 3428, 33428, 3927, 33927},    /* DDR2-667 SC */
        {0, 0, 667, 800, 3443, 33443, 3905, 33905},    /* DDR2-800 SC */
        {0, 1, 667, 667, 6494, 36494, 6993, 36993},    /* DDR3-667 SC */
        {0, 1, 667, 800, 5998, 35998, 6460, 36460},    /* DDR3-800 SC */

        {0, 0, 400, 400, 3528, 33528, 4255, 34255},    /* DDR2-400 SC */
        {0, 0, 400, 667, 3500, 33500, 4079, 34079},    /* DDR2-667 SC */
        {0, 0, 400, 800, 3487, 33487, 4029, 34029},    /* DDR2-800 SC */
        {0, 1, 400, 667, 6566, 36566, 7145, 37145},    /* DDR3-667 SC */
        {0, 1, 400, 800, 6042, 36042, 6584, 36584},    /* DDR3-800 SC */
};

static const struct cxsr_latency *intel_get_cxsr_latency(int is_desktop,
                                                         int is_ddr3,
                                                         int fsb,
                                                         int mem)
{
        const struct cxsr_latency *latency;
        int i;

        if (fsb == 0 || mem == 0)
                return NULL;

        for (i = 0; i < DRM_ARRAY_SIZE(cxsr_latency_table); i++) {
                latency = &cxsr_latency_table[i];
                if (is_desktop == latency->is_desktop &&
                    is_ddr3 == latency->is_ddr3 &&
                    fsb == latency->fsb_freq && mem == latency->mem_freq)
                        return latency;
        }

        DRM_DEBUG_KMS("Unknown FSB/MEM found, disable CxSR\n");

        return NULL;
}

static void pineview_disable_cxsr(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        /* deactivate cxsr */
        I915_WRITE(DSPFW3, I915_READ(DSPFW3) & ~PINEVIEW_SELF_REFRESH_EN);
}

/*
 * Latency for FIFO fetches is dependent on several factors:
 *   - memory configuration (speed, channels)
 *   - chipset
 *   - current MCH state
 * It can be fairly high in some situations, so here we assume a fairly
 * pessimal value.  It's a tradeoff between extra memory fetches (if we
 * set this value too high, the FIFO will fetch frequently to stay full)
 * and power consumption (set it too low to save power and we might see
 * FIFO underruns and display "flicker").
 *
 * A value of 5us seems to be a good balance; safe for very low end
 * platforms but not overly aggressive on lower latency configs.
 */
static const int latency_ns = 5000;

static int i9xx_get_fifo_size(struct drm_device *dev, int plane)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        uint32_t dsparb = I915_READ(DSPARB);
        int size;

        size = dsparb & 0x7f;
        if (plane)
                size = ((dsparb >> DSPARB_CSTART_SHIFT) & 0x7f) - size;

        DRM_DEBUG_KMS("FIFO size - (0x%08x) %s: %d\n", dsparb,
                      plane ? "B" : "A", size);

        return size;
}

static int i85x_get_fifo_size(struct drm_device *dev, int plane)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        uint32_t dsparb = I915_READ(DSPARB);
        int size;

        size = dsparb & 0x1ff;
        if (plane)
                size = ((dsparb >> DSPARB_BEND_SHIFT) & 0x1ff) - size;
        size >>= 1; /* Convert to cachelines */

        DRM_DEBUG_KMS("FIFO size - (0x%08x) %s: %d\n", dsparb,
                      plane ? "B" : "A", size);

        return size;
}

static int i845_get_fifo_size(struct drm_device *dev, int plane)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        uint32_t dsparb = I915_READ(DSPARB);
        int size;

        size = dsparb & 0x7f;
        size >>= 2; /* Convert to cachelines */

        DRM_DEBUG_KMS("FIFO size - (0x%08x) %s: %d\n", dsparb,
                      plane ? "B" : "A",
                      size);

        return size;
}

static int i830_get_fifo_size(struct drm_device *dev, int plane)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        uint32_t dsparb = I915_READ(DSPARB);
        int size;

        size = dsparb & 0x7f;
        size >>= 1; /* Convert to cachelines */

        DRM_DEBUG_KMS("FIFO size - (0x%08x) %s: %d\n", dsparb,
                      plane ? "B" : "A", size);

        return size;
}

/* Pineview has different values for various configs */
static const struct intel_watermark_params pineview_display_wm = {
        PINEVIEW_DISPLAY_FIFO,
        PINEVIEW_MAX_WM,
        PINEVIEW_DFT_WM,
        PINEVIEW_GUARD_WM,
        PINEVIEW_FIFO_LINE_SIZE
};
static const struct intel_watermark_params pineview_display_hplloff_wm = {
        PINEVIEW_DISPLAY_FIFO,
        PINEVIEW_MAX_WM,
        PINEVIEW_DFT_HPLLOFF_WM,
        PINEVIEW_GUARD_WM,
        PINEVIEW_FIFO_LINE_SIZE
};
static const struct intel_watermark_params pineview_cursor_wm = {
        PINEVIEW_CURSOR_FIFO,
        PINEVIEW_CURSOR_MAX_WM,
        PINEVIEW_CURSOR_DFT_WM,
        PINEVIEW_CURSOR_GUARD_WM,
        PINEVIEW_FIFO_LINE_SIZE,
};
static const struct intel_watermark_params pineview_cursor_hplloff_wm = {
        PINEVIEW_CURSOR_FIFO,
        PINEVIEW_CURSOR_MAX_WM,
        PINEVIEW_CURSOR_DFT_WM,
        PINEVIEW_CURSOR_GUARD_WM,
        PINEVIEW_FIFO_LINE_SIZE
};
static const struct intel_watermark_params g4x_wm_info = {
        G4X_FIFO_SIZE,
        G4X_MAX_WM,
        G4X_MAX_WM,
        2,
        G4X_FIFO_LINE_SIZE,
};
static const struct intel_watermark_params g4x_cursor_wm_info = {
        I965_CURSOR_FIFO,
        I965_CURSOR_MAX_WM,
        I965_CURSOR_DFT_WM,
        2,
        G4X_FIFO_LINE_SIZE,
};
static const struct intel_watermark_params valleyview_wm_info = {
        VALLEYVIEW_FIFO_SIZE,
        VALLEYVIEW_MAX_WM,
        VALLEYVIEW_MAX_WM,
        2,
        G4X_FIFO_LINE_SIZE,
};
static const struct intel_watermark_params valleyview_cursor_wm_info = {
        I965_CURSOR_FIFO,
        VALLEYVIEW_CURSOR_MAX_WM,
        I965_CURSOR_DFT_WM,
        2,
        G4X_FIFO_LINE_SIZE,
};
static const struct intel_watermark_params i965_cursor_wm_info = {
        I965_CURSOR_FIFO,
        I965_CURSOR_MAX_WM,
        I965_CURSOR_DFT_WM,
        2,
        I915_FIFO_LINE_SIZE,
};
static const struct intel_watermark_params i945_wm_info = {
        I945_FIFO_SIZE,
        I915_MAX_WM,
        1,
        2,
        I915_FIFO_LINE_SIZE
};
static const struct intel_watermark_params i915_wm_info = {
        I915_FIFO_SIZE,
        I915_MAX_WM,
        1,
        2,
        I915_FIFO_LINE_SIZE
};
static const struct intel_watermark_params i855_wm_info = {
        I855GM_FIFO_SIZE,
        I915_MAX_WM,
        1,
        2,
        I830_FIFO_LINE_SIZE
};
static const struct intel_watermark_params i830_wm_info = {
        I830_FIFO_SIZE,
        I915_MAX_WM,
        1,
        2,
        I830_FIFO_LINE_SIZE
};

static const struct intel_watermark_params ironlake_display_wm_info = {
        ILK_DISPLAY_FIFO,
        ILK_DISPLAY_MAXWM,
        ILK_DISPLAY_DFTWM,
        2,
        ILK_FIFO_LINE_SIZE
};
static const struct intel_watermark_params ironlake_cursor_wm_info = {
        ILK_CURSOR_FIFO,
        ILK_CURSOR_MAXWM,
        ILK_CURSOR_DFTWM,
        2,
        ILK_FIFO_LINE_SIZE
};
static const struct intel_watermark_params ironlake_display_srwm_info = {
        ILK_DISPLAY_SR_FIFO,
        ILK_DISPLAY_MAX_SRWM,
        ILK_DISPLAY_DFT_SRWM,
        2,
        ILK_FIFO_LINE_SIZE
};
static const struct intel_watermark_params ironlake_cursor_srwm_info = {
        ILK_CURSOR_SR_FIFO,
        ILK_CURSOR_MAX_SRWM,
        ILK_CURSOR_DFT_SRWM,
        2,
        ILK_FIFO_LINE_SIZE
};

static const struct intel_watermark_params sandybridge_display_wm_info = {
        SNB_DISPLAY_FIFO,
        SNB_DISPLAY_MAXWM,
        SNB_DISPLAY_DFTWM,
        2,
        SNB_FIFO_LINE_SIZE
};
static const struct intel_watermark_params sandybridge_cursor_wm_info = {
        SNB_CURSOR_FIFO,
        SNB_CURSOR_MAXWM,
        SNB_CURSOR_DFTWM,
        2,
        SNB_FIFO_LINE_SIZE
};
static const struct intel_watermark_params sandybridge_display_srwm_info = {
        SNB_DISPLAY_SR_FIFO,
        SNB_DISPLAY_MAX_SRWM,
        SNB_DISPLAY_DFT_SRWM,
        2,
        SNB_FIFO_LINE_SIZE
};
static const struct intel_watermark_params sandybridge_cursor_srwm_info = {
        SNB_CURSOR_SR_FIFO,
        SNB_CURSOR_MAX_SRWM,
        SNB_CURSOR_DFT_SRWM,
        2,
        SNB_FIFO_LINE_SIZE
};


/**
 * intel_calculate_wm - calculate watermark level
 * @clock_in_khz: pixel clock
 * @wm: chip FIFO params
 * @pixel_size: display pixel size
 * @latency_ns: memory latency for the platform
 *
 * Calculate the watermark level (the level at which the display plane will
 * start fetching from memory again).  Each chip has a different display
 * FIFO size and allocation, so the caller needs to figure that out and pass
 * in the correct intel_watermark_params structure.
 *
 * As the pixel clock runs, the FIFO will be drained at a rate that depends
 * on the pixel size.  When it reaches the watermark level, it'll start
 * fetching FIFO line sized based chunks from memory until the FIFO fills
 * past the watermark point.  If the FIFO drains completely, a FIFO underrun
 * will occur, and a display engine hang could result.
 */
static unsigned long intel_calculate_wm(unsigned long clock_in_khz,
                                        const struct intel_watermark_params *wm,
                                        int fifo_size,
                                        int pixel_size,
                                        unsigned long latency_ns)
{
        long entries_required, wm_size;

        /*
         * Note: we need to make sure we don't overflow for various clock &
         * latency values.
         * clocks go from a few thousand to several hundred thousand.
         * latency is usually a few thousand
         */
        entries_required = ((clock_in_khz / 1000) * pixel_size * latency_ns) /
                1000;
        entries_required = DIV_ROUND_UP(entries_required, wm->cacheline_size);

        DRM_DEBUG_KMS("FIFO entries required for mode: %ld\n", entries_required);

        wm_size = fifo_size - (entries_required + wm->guard_size);

        DRM_DEBUG_KMS("FIFO watermark level: %ld\n", wm_size);

        /* Don't promote wm_size to unsigned... */
        if (wm_size > (long)wm->max_wm)
                wm_size = wm->max_wm;
        if (wm_size <= 0)
                wm_size = wm->default_wm;
        return wm_size;
}

static struct drm_crtc *single_enabled_crtc(struct drm_device *dev)
{
        struct drm_crtc *crtc, *enabled = NULL;

        list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
                if (crtc->enabled && crtc->fb) {
                        if (enabled)
                                return NULL;
                        enabled = crtc;
                }
        }

        return enabled;
}

static void pineview_update_wm(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct drm_crtc *crtc;
        const struct cxsr_latency *latency;
        u32 reg;
        unsigned long wm;

        latency = intel_get_cxsr_latency(IS_PINEVIEW_G(dev), dev_priv->is_ddr3,
                                         dev_priv->fsb_freq, dev_priv->mem_freq);
        if (!latency) {
                DRM_DEBUG_KMS("Unknown FSB/MEM found, disable CxSR\n");
                pineview_disable_cxsr(dev);
                return;
        }

        crtc = single_enabled_crtc(dev);
        if (crtc) {
                int clock = crtc->mode.clock;
                int pixel_size = crtc->fb->bits_per_pixel / 8;

                /* Display SR */
                wm = intel_calculate_wm(clock, &pineview_display_wm,
                                        pineview_display_wm.fifo_size,
                                        pixel_size, latency->display_sr);
                reg = I915_READ(DSPFW1);
                reg &= ~DSPFW_SR_MASK;
                reg |= wm << DSPFW_SR_SHIFT;
                I915_WRITE(DSPFW1, reg);
                DRM_DEBUG_KMS("DSPFW1 register is %x\n", reg);

                /* cursor SR */
                wm = intel_calculate_wm(clock, &pineview_cursor_wm,
                                        pineview_display_wm.fifo_size,
                                        pixel_size, latency->cursor_sr);
                reg = I915_READ(DSPFW3);
                reg &= ~DSPFW_CURSOR_SR_MASK;
                reg |= (wm & 0x3f) << DSPFW_CURSOR_SR_SHIFT;
                I915_WRITE(DSPFW3, reg);

                /* Display HPLL off SR */
                wm = intel_calculate_wm(clock, &pineview_display_hplloff_wm,
                                        pineview_display_hplloff_wm.fifo_size,
                                        pixel_size, latency->display_hpll_disable);
                reg = I915_READ(DSPFW3);
                reg &= ~DSPFW_HPLL_SR_MASK;
                reg |= wm & DSPFW_HPLL_SR_MASK;
                I915_WRITE(DSPFW3, reg);

                /* cursor HPLL off SR */
                wm = intel_calculate_wm(clock, &pineview_cursor_hplloff_wm,
                                        pineview_display_hplloff_wm.fifo_size,
                                        pixel_size, latency->cursor_hpll_disable);
                reg = I915_READ(DSPFW3);
                reg &= ~DSPFW_HPLL_CURSOR_MASK;
                reg |= (wm & 0x3f) << DSPFW_HPLL_CURSOR_SHIFT;
                I915_WRITE(DSPFW3, reg);
                DRM_DEBUG_KMS("DSPFW3 register is %x\n", reg);

                /* activate cxsr */
                I915_WRITE(DSPFW3,
                           I915_READ(DSPFW3) | PINEVIEW_SELF_REFRESH_EN);
                DRM_DEBUG_KMS("Self-refresh is enabled\n");
        } else {
                pineview_disable_cxsr(dev);
                DRM_DEBUG_KMS("Self-refresh is disabled\n");
        }
}

static bool g4x_compute_wm0(struct drm_device *dev,
                            int plane,
                            const struct intel_watermark_params *display,
                            int display_latency_ns,
                            const struct intel_watermark_params *cursor,
                            int cursor_latency_ns,
                            int *plane_wm,
                            int *cursor_wm)
{
        struct drm_crtc *crtc;
        int htotal, hdisplay, clock, pixel_size;
        int line_time_us, line_count;
        int entries, tlb_miss;

        crtc = intel_get_crtc_for_plane(dev, plane);
        if (crtc->fb == NULL || !crtc->enabled) {
                *cursor_wm = cursor->guard_size;
                *plane_wm = display->guard_size;
                return false;
        }

        htotal = crtc->mode.htotal;
        hdisplay = crtc->mode.hdisplay;
        clock = crtc->mode.clock;
        pixel_size = crtc->fb->bits_per_pixel / 8;

        /* Use the small buffer method to calculate plane watermark */
        entries = ((clock * pixel_size / 1000) * display_latency_ns) / 1000;
        tlb_miss = display->fifo_size*display->cacheline_size - hdisplay * 8;
        if (tlb_miss > 0)
                entries += tlb_miss;
        entries = DIV_ROUND_UP(entries, display->cacheline_size);
        *plane_wm = entries + display->guard_size;
        if (*plane_wm > (int)display->max_wm)
                *plane_wm = display->max_wm;

        /* Use the large buffer method to calculate cursor watermark */
        line_time_us = ((htotal * 1000) / clock);
        line_count = (cursor_latency_ns / line_time_us + 1000) / 1000;
        entries = line_count * 64 * pixel_size;
        tlb_miss = cursor->fifo_size*cursor->cacheline_size - hdisplay * 8;
        if (tlb_miss > 0)
                entries += tlb_miss;
        entries = DIV_ROUND_UP(entries, cursor->cacheline_size);
        *cursor_wm = entries + cursor->guard_size;
        if (*cursor_wm > (int)cursor->max_wm)
                *cursor_wm = (int)cursor->max_wm;

        return true;
}

/*
 * Check the wm result.
 *
 * If any calculated watermark values is larger than the maximum value that
 * can be programmed into the associated watermark register, that watermark
 * must be disabled.
 */
static bool g4x_check_srwm(struct drm_device *dev,
                           int display_wm, int cursor_wm,
                           const struct intel_watermark_params *display,
                           const struct intel_watermark_params *cursor)
{
        DRM_DEBUG_KMS("SR watermark: display plane %d, cursor %d\n",
                      display_wm, cursor_wm);

        if (display_wm > display->max_wm) {
                DRM_DEBUG_KMS("display watermark is too large(%d/%ld), disabling\n",
                              display_wm, display->max_wm);
                return false;
        }

        if (cursor_wm > cursor->max_wm) {
                DRM_DEBUG_KMS("cursor watermark is too large(%d/%ld), disabling\n",
                              cursor_wm, cursor->max_wm);
                return false;
        }

        if (!(display_wm || cursor_wm)) {
                DRM_DEBUG_KMS("SR latency is 0, disabling\n");
                return false;
        }

        return true;
}

static bool g4x_compute_srwm(struct drm_device *dev,
                             int plane,
                             int latency_ns,
                             const struct intel_watermark_params *display,
                             const struct intel_watermark_params *cursor,
                             int *display_wm, int *cursor_wm)
{
        struct drm_crtc *crtc;
        int hdisplay, htotal, pixel_size, clock;
        unsigned long line_time_us;
        int line_count, line_size;
        int small, large;
        int entries;

        if (!latency_ns) {
                *display_wm = *cursor_wm = 0;
                return false;
        }

        crtc = intel_get_crtc_for_plane(dev, plane);
        hdisplay = crtc->mode.hdisplay;
        htotal = crtc->mode.htotal;
        clock = crtc->mode.clock;
        pixel_size = crtc->fb->bits_per_pixel / 8;

        line_time_us = (htotal * 1000) / clock;
        line_count = (latency_ns / line_time_us + 1000) / 1000;
        line_size = hdisplay * pixel_size;

        /* Use the minimum of the small and large buffer method for primary */
        small = ((clock * pixel_size / 1000) * latency_ns) / 1000;
        large = line_count * line_size;

        entries = DIV_ROUND_UP(min(small, large), display->cacheline_size);
        *display_wm = entries + display->guard_size;

        /* calculate the self-refresh watermark for display cursor */
        entries = line_count * pixel_size * 64;
        entries = DIV_ROUND_UP(entries, cursor->cacheline_size);
        *cursor_wm = entries + cursor->guard_size;

        return g4x_check_srwm(dev,
                              *display_wm, *cursor_wm,
                              display, cursor);
}

static bool vlv_compute_drain_latency(struct drm_device *dev,
                                     int plane,
                                     int *plane_prec_mult,
                                     int *plane_dl,
                                     int *cursor_prec_mult,
                                     int *cursor_dl)
{
        struct drm_crtc *crtc;
        int clock, pixel_size;
        int entries;

        crtc = intel_get_crtc_for_plane(dev, plane);
        if (crtc->fb == NULL || !crtc->enabled)
                return false;

        clock = crtc->mode.clock;       /* VESA DOT Clock */
        pixel_size = crtc->fb->bits_per_pixel / 8;      /* BPP */

        entries = (clock / 1000) * pixel_size;
        *plane_prec_mult = (entries > 256) ?
                DRAIN_LATENCY_PRECISION_32 : DRAIN_LATENCY_PRECISION_16;
        *plane_dl = (64 * (*plane_prec_mult) * 4) / ((clock / 1000) *
                                                     pixel_size);

        entries = (clock / 1000) * 4;   /* BPP is always 4 for cursor */
        *cursor_prec_mult = (entries > 256) ?
                DRAIN_LATENCY_PRECISION_32 : DRAIN_LATENCY_PRECISION_16;
        *cursor_dl = (64 * (*cursor_prec_mult) * 4) / ((clock / 1000) * 4);

        return true;
}

/*
 * Update drain latency registers of memory arbiter
 *
 * Valleyview SoC has a new memory arbiter and needs drain latency registers
 * to be programmed. Each plane has a drain latency multiplier and a drain
 * latency value.
 */

static void vlv_update_drain_latency(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        int planea_prec, planea_dl, planeb_prec, planeb_dl;
        int cursora_prec, cursora_dl, cursorb_prec, cursorb_dl;
        int plane_prec_mult, cursor_prec_mult; /* Precision multiplier is
                                                        either 16 or 32 */

        /* For plane A, Cursor A */
        if (vlv_compute_drain_latency(dev, 0, &plane_prec_mult, &planea_dl,
                                      &cursor_prec_mult, &cursora_dl)) {
                cursora_prec = (cursor_prec_mult == DRAIN_LATENCY_PRECISION_32) ?
                        DDL_CURSORA_PRECISION_32 : DDL_CURSORA_PRECISION_16;
                planea_prec = (plane_prec_mult == DRAIN_LATENCY_PRECISION_32) ?
                        DDL_PLANEA_PRECISION_32 : DDL_PLANEA_PRECISION_16;

                I915_WRITE(VLV_DDL1, cursora_prec |
                                (cursora_dl << DDL_CURSORA_SHIFT) |
                                planea_prec | planea_dl);
        }

        /* For plane B, Cursor B */
        if (vlv_compute_drain_latency(dev, 1, &plane_prec_mult, &planeb_dl,
                                      &cursor_prec_mult, &cursorb_dl)) {
                cursorb_prec = (cursor_prec_mult == DRAIN_LATENCY_PRECISION_32) ?
                        DDL_CURSORB_PRECISION_32 : DDL_CURSORB_PRECISION_16;
                planeb_prec = (plane_prec_mult == DRAIN_LATENCY_PRECISION_32) ?
                        DDL_PLANEB_PRECISION_32 : DDL_PLANEB_PRECISION_16;

                I915_WRITE(VLV_DDL2, cursorb_prec |
                                (cursorb_dl << DDL_CURSORB_SHIFT) |
                                planeb_prec | planeb_dl);
        }
}

#define single_plane_enabled(mask) ((mask) != 0 && powerof2(mask))

static void valleyview_update_wm(struct drm_device *dev)
{
        static const int sr_latency_ns = 12000;
        struct drm_i915_private *dev_priv = dev->dev_private;
        int planea_wm, planeb_wm, cursora_wm, cursorb_wm;
        int plane_sr, cursor_sr;
        unsigned int enabled = 0;

        vlv_update_drain_latency(dev);

        if (g4x_compute_wm0(dev, 0,
                            &valleyview_wm_info, latency_ns,
                            &valleyview_cursor_wm_info, latency_ns,
                            &planea_wm, &cursora_wm))
                enabled |= 1;

        if (g4x_compute_wm0(dev, 1,
                            &valleyview_wm_info, latency_ns,
                            &valleyview_cursor_wm_info, latency_ns,
                            &planeb_wm, &cursorb_wm))
                enabled |= 2;

        plane_sr = cursor_sr = 0;
        if (single_plane_enabled(enabled) &&
            g4x_compute_srwm(dev, ffs(enabled) - 1,
                             sr_latency_ns,
                             &valleyview_wm_info,
                             &valleyview_cursor_wm_info,
                             &plane_sr, &cursor_sr))
                I915_WRITE(FW_BLC_SELF_VLV, FW_CSPWRDWNEN);
        else
                I915_WRITE(FW_BLC_SELF_VLV,
                           I915_READ(FW_BLC_SELF_VLV) & ~FW_CSPWRDWNEN);

        DRM_DEBUG_KMS("Setting FIFO watermarks - A: plane=%d, cursor=%d, B: plane=%d, cursor=%d, SR: plane=%d, cursor=%d\n",
                      planea_wm, cursora_wm,
                      planeb_wm, cursorb_wm,
                      plane_sr, cursor_sr);

        I915_WRITE(DSPFW1,
                   (plane_sr << DSPFW_SR_SHIFT) |
                   (cursorb_wm << DSPFW_CURSORB_SHIFT) |
                   (planeb_wm << DSPFW_PLANEB_SHIFT) |
                   planea_wm);
        I915_WRITE(DSPFW2,
                   (I915_READ(DSPFW2) & DSPFW_CURSORA_MASK) |
                   (cursora_wm << DSPFW_CURSORA_SHIFT));
        I915_WRITE(DSPFW3,
                   (I915_READ(DSPFW3) | (cursor_sr << DSPFW_CURSOR_SR_SHIFT)));
}

static void g4x_update_wm(struct drm_device *dev)
{
        static const int sr_latency_ns = 12000;
        struct drm_i915_private *dev_priv = dev->dev_private;
        int planea_wm, planeb_wm, cursora_wm, cursorb_wm;
        int plane_sr, cursor_sr;
        unsigned int enabled = 0;

        if (g4x_compute_wm0(dev, 0,
                            &g4x_wm_info, latency_ns,
                            &g4x_cursor_wm_info, latency_ns,
                            &planea_wm, &cursora_wm))
                enabled |= 1;

        if (g4x_compute_wm0(dev, 1,
                            &g4x_wm_info, latency_ns,
                            &g4x_cursor_wm_info, latency_ns,
                            &planeb_wm, &cursorb_wm))
                enabled |= 2;

        plane_sr = cursor_sr = 0;
        if (single_plane_enabled(enabled) &&
            g4x_compute_srwm(dev, ffs(enabled) - 1,
                             sr_latency_ns,
                             &g4x_wm_info,
                             &g4x_cursor_wm_info,
                             &plane_sr, &cursor_sr))
                I915_WRITE(FW_BLC_SELF, FW_BLC_SELF_EN);
        else
                I915_WRITE(FW_BLC_SELF,
                           I915_READ(FW_BLC_SELF) & ~FW_BLC_SELF_EN);

        DRM_DEBUG_KMS("Setting FIFO watermarks - A: plane=%d, cursor=%d, B: plane=%d, cursor=%d, SR: plane=%d, cursor=%d\n",
                      planea_wm, cursora_wm,
                      planeb_wm, cursorb_wm,
                      plane_sr, cursor_sr);

        I915_WRITE(DSPFW1,
                   (plane_sr << DSPFW_SR_SHIFT) |
                   (cursorb_wm << DSPFW_CURSORB_SHIFT) |
                   (planeb_wm << DSPFW_PLANEB_SHIFT) |
                   planea_wm);
        I915_WRITE(DSPFW2,
                   (I915_READ(DSPFW2) & DSPFW_CURSORA_MASK) |
                   (cursora_wm << DSPFW_CURSORA_SHIFT));
        /* HPLL off in SR has some issues on G4x... disable it */
        I915_WRITE(DSPFW3,
                   (I915_READ(DSPFW3) & ~DSPFW_HPLL_SR_EN) |
                   (cursor_sr << DSPFW_CURSOR_SR_SHIFT));
}

static void i965_update_wm(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct drm_crtc *crtc;
        int srwm = 1;
        int cursor_sr = 16;

        /* Calc sr entries for one plane configs */
        crtc = single_enabled_crtc(dev);
        if (crtc) {
                /* self-refresh has much higher latency */
                static const int sr_latency_ns = 12000;
                int clock = crtc->mode.clock;
                int htotal = crtc->mode.htotal;
                int hdisplay = crtc->mode.hdisplay;
                int pixel_size = crtc->fb->bits_per_pixel / 8;
                unsigned long line_time_us;
                int entries;

                line_time_us = ((htotal * 1000) / clock);

                /* Use ns/us then divide to preserve precision */
                entries = (((sr_latency_ns / line_time_us) + 1000) / 1000) *
                        pixel_size * hdisplay;
                entries = DIV_ROUND_UP(entries, I915_FIFO_LINE_SIZE);
                srwm = I965_FIFO_SIZE - entries;
                if (srwm < 0)
                        srwm = 1;
                srwm &= 0x1ff;
                DRM_DEBUG_KMS("self-refresh entries: %d, wm: %d\n",
                              entries, srwm);

                entries = (((sr_latency_ns / line_time_us) + 1000) / 1000) *
                        pixel_size * 64;
                entries = DIV_ROUND_UP(entries,
                                          i965_cursor_wm_info.cacheline_size);
                cursor_sr = i965_cursor_wm_info.fifo_size -
                        (entries + i965_cursor_wm_info.guard_size);

                if (cursor_sr > i965_cursor_wm_info.max_wm)
                        cursor_sr = i965_cursor_wm_info.max_wm;

                DRM_DEBUG_KMS("self-refresh watermark: display plane %d "
                              "cursor %d\n", srwm, cursor_sr);

                if (IS_CRESTLINE(dev))
                        I915_WRITE(FW_BLC_SELF, FW_BLC_SELF_EN);
        } else {
                /* Turn off self refresh if both pipes are enabled */
                if (IS_CRESTLINE(dev))
                        I915_WRITE(FW_BLC_SELF, I915_READ(FW_BLC_SELF)
                                   & ~FW_BLC_SELF_EN);
        }

        DRM_DEBUG_KMS("Setting FIFO watermarks - A: 8, B: 8, C: 8, SR %d\n",
                      srwm);

        /* 965 has limitations... */
        I915_WRITE(DSPFW1, (srwm << DSPFW_SR_SHIFT) |
                   (8 << 16) | (8 << 8) | (8 << 0));
        I915_WRITE(DSPFW2, (8 << 8) | (8 << 0));
        /* update cursor SR watermark */
        I915_WRITE(DSPFW3, (cursor_sr << DSPFW_CURSOR_SR_SHIFT));
}

static void i9xx_update_wm(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        const struct intel_watermark_params *wm_info;
        uint32_t fwater_lo;
        uint32_t fwater_hi;
        int cwm, srwm = 1;
        int fifo_size;
        int planea_wm, planeb_wm;
        struct drm_crtc *crtc, *enabled = NULL;

        if (IS_I945GM(dev))
                wm_info = &i945_wm_info;
        else if (!IS_GEN2(dev))
                wm_info = &i915_wm_info;
        else
                wm_info = &i855_wm_info;

        fifo_size = dev_priv->display.get_fifo_size(dev, 0);
        crtc = intel_get_crtc_for_plane(dev, 0);
        if (crtc->enabled && crtc->fb) {
                planea_wm = intel_calculate_wm(crtc->mode.clock,
                                               wm_info, fifo_size,
                                               crtc->fb->bits_per_pixel / 8,
                                               latency_ns);
                enabled = crtc;
        } else
                planea_wm = fifo_size - wm_info->guard_size;

        fifo_size = dev_priv->display.get_fifo_size(dev, 1);
        crtc = intel_get_crtc_for_plane(dev, 1);
        if (crtc->enabled && crtc->fb) {
                planeb_wm = intel_calculate_wm(crtc->mode.clock,
                                               wm_info, fifo_size,
                                               crtc->fb->bits_per_pixel / 8,
                                               latency_ns);
                if (enabled == NULL)
                        enabled = crtc;
                else
                        enabled = NULL;
        } else
                planeb_wm = fifo_size - wm_info->guard_size;

        DRM_DEBUG_KMS("FIFO watermarks - A: %d, B: %d\n", planea_wm, planeb_wm);

        /*
         * Overlay gets an aggressive default since video jitter is bad.
         */
        cwm = 2;

        /* Play safe and disable self-refresh before adjusting watermarks. */
        if (IS_I945G(dev) || IS_I945GM(dev))
                I915_WRITE(FW_BLC_SELF, FW_BLC_SELF_EN_MASK | 0);
        else if (IS_I915GM(dev))
                I915_WRITE(INSTPM, I915_READ(INSTPM) & ~INSTPM_SELF_EN);

        /* Calc sr entries for one plane configs */
        if (HAS_FW_BLC(dev) && enabled) {
                /* self-refresh has much higher latency */
                static const int sr_latency_ns = 6000;
                int clock = enabled->mode.clock;
                int htotal = enabled->mode.htotal;
                int hdisplay = enabled->mode.hdisplay;
                int pixel_size = enabled->fb->bits_per_pixel / 8;
                unsigned long line_time_us;
                int entries;

                line_time_us = (htotal * 1000) / clock;

                /* Use ns/us then divide to preserve precision */
                entries = (((sr_latency_ns / line_time_us) + 1000) / 1000) *
                        pixel_size * hdisplay;
                entries = DIV_ROUND_UP(entries, wm_info->cacheline_size);
                DRM_DEBUG_KMS("self-refresh entries: %d\n", entries);
                srwm = wm_info->fifo_size - entries;
                if (srwm < 0)
                        srwm = 1;

                if (IS_I945G(dev) || IS_I945GM(dev))
                        I915_WRITE(FW_BLC_SELF,
                                   FW_BLC_SELF_FIFO_MASK | (srwm & 0xff));
                else if (IS_I915GM(dev))
                        I915_WRITE(FW_BLC_SELF, srwm & 0x3f);
        }

        DRM_DEBUG_KMS("Setting FIFO watermarks - A: %d, B: %d, C: %d, SR %d\n",
                      planea_wm, planeb_wm, cwm, srwm);

        fwater_lo = ((planeb_wm & 0x3f) << 16) | (planea_wm & 0x3f);
        fwater_hi = (cwm & 0x1f);

        /* Set request length to 8 cachelines per fetch */
        fwater_lo = fwater_lo | (1 << 24) | (1 << 8);
        fwater_hi = fwater_hi | (1 << 8);

        I915_WRITE(FW_BLC, fwater_lo);
        I915_WRITE(FW_BLC2, fwater_hi);

        if (HAS_FW_BLC(dev)) {
                if (enabled) {
                        if (IS_I945G(dev) || IS_I945GM(dev))
                                I915_WRITE(FW_BLC_SELF,
                                           FW_BLC_SELF_EN_MASK | FW_BLC_SELF_EN);
                        else if (IS_I915GM(dev))
                                I915_WRITE(INSTPM, I915_READ(INSTPM) | INSTPM_SELF_EN);
                        DRM_DEBUG_KMS("memory self refresh enabled\n");
                } else
                        DRM_DEBUG_KMS("memory self refresh disabled\n");
        }
}

static void i830_update_wm(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct drm_crtc *crtc;
        uint32_t fwater_lo;
        int planea_wm;

        crtc = single_enabled_crtc(dev);
        if (crtc == NULL)
                return;

        planea_wm = intel_calculate_wm(crtc->mode.clock, &i830_wm_info,
                                       dev_priv->display.get_fifo_size(dev, 0),
                                       crtc->fb->bits_per_pixel / 8,
                                       latency_ns);
        fwater_lo = I915_READ(FW_BLC) & ~0xfff;
        fwater_lo |= (3<<8) | planea_wm;

        DRM_DEBUG_KMS("Setting FIFO watermarks - A: %d\n", planea_wm);

        I915_WRITE(FW_BLC, fwater_lo);
}

#define ILK_LP0_PLANE_LATENCY           700
#define ILK_LP0_CURSOR_LATENCY          1300

/*
 * Check the wm result.
 *
 * If any calculated watermark values is larger than the maximum value that
 * can be programmed into the associated watermark register, that watermark
 * must be disabled.
 */
static bool ironlake_check_srwm(struct drm_device *dev, int level,
                                int fbc_wm, int display_wm, int cursor_wm,
                                const struct intel_watermark_params *display,
                                const struct intel_watermark_params *cursor)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        DRM_DEBUG_KMS("watermark %d: display plane %d, fbc lines %d,"
                      " cursor %d\n", level, display_wm, fbc_wm, cursor_wm);

        if (fbc_wm > SNB_FBC_MAX_SRWM) {
                DRM_DEBUG_KMS("fbc watermark(%d) is too large(%d), disabling wm%d+\n",
                              fbc_wm, SNB_FBC_MAX_SRWM, level);

                /* fbc has it's own way to disable FBC WM */
                I915_WRITE(DISP_ARB_CTL,
                           I915_READ(DISP_ARB_CTL) | DISP_FBC_WM_DIS);
                return false;
        }

        if (display_wm > display->max_wm) {
                DRM_DEBUG_KMS("display watermark(%d) is too large(%d), disabling wm%d+\n",
                              display_wm, SNB_DISPLAY_MAX_SRWM, level);
                return false;
        }

        if (cursor_wm > cursor->max_wm) {
                DRM_DEBUG_KMS("cursor watermark(%d) is too large(%d), disabling wm%d+\n",
                              cursor_wm, SNB_CURSOR_MAX_SRWM, level);
                return false;
        }

        if (!(fbc_wm || display_wm || cursor_wm)) {
                DRM_DEBUG_KMS("latency %d is 0, disabling wm%d+\n", level, level);
                return false;
        }

        return true;
}

/*
 * Compute watermark values of WM[1-3],
 */
static bool ironlake_compute_srwm(struct drm_device *dev, int level, int plane,
                                  int latency_ns,
                                  const struct intel_watermark_params *display,
                                  const struct intel_watermark_params *cursor,
                                  int *fbc_wm, int *display_wm, int *cursor_wm)
{
        struct drm_crtc *crtc;
        unsigned long line_time_us;
        int hdisplay, htotal, pixel_size, clock;
        int line_count, line_size;
        int small, large;
        int entries;

        if (!latency_ns) {
                *fbc_wm = *display_wm = *cursor_wm = 0;
                return false;
        }

        crtc = intel_get_crtc_for_plane(dev, plane);
        hdisplay = crtc->mode.hdisplay;
        htotal = crtc->mode.htotal;
        clock = crtc->mode.clock;
        pixel_size = crtc->fb->bits_per_pixel / 8;

        line_time_us = (htotal * 1000) / clock;
        line_count = (latency_ns / line_time_us + 1000) / 1000;
        line_size = hdisplay * pixel_size;

        /* Use the minimum of the small and large buffer method for primary */
        small = ((clock * pixel_size / 1000) * latency_ns) / 1000;
        large = line_count * line_size;

        entries = DIV_ROUND_UP(min(small, large), display->cacheline_size);
        *display_wm = entries + display->guard_size;

        /*
         * Spec says:
         * FBC WM = ((Final Primary WM * 64) / number of bytes per line) + 2
         */
        *fbc_wm = DIV_ROUND_UP(*display_wm * 64, line_size) + 2;

        /* calculate the self-refresh watermark for display cursor */
        entries = line_count * pixel_size * 64;
        entries = DIV_ROUND_UP(entries, cursor->cacheline_size);
        *cursor_wm = entries + cursor->guard_size;

        return ironlake_check_srwm(dev, level,
                                   *fbc_wm, *display_wm, *cursor_wm,
                                   display, cursor);
}

static void ironlake_update_wm(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        int fbc_wm, plane_wm, cursor_wm;
        unsigned int enabled;

        enabled = 0;
        if (g4x_compute_wm0(dev, 0,
                            &ironlake_display_wm_info,
                            ILK_LP0_PLANE_LATENCY,
                            &ironlake_cursor_wm_info,
                            ILK_LP0_CURSOR_LATENCY,
                            &plane_wm, &cursor_wm)) {
                I915_WRITE(WM0_PIPEA_ILK,
                           (plane_wm << WM0_PIPE_PLANE_SHIFT) | cursor_wm);
                DRM_DEBUG_KMS("FIFO watermarks For pipe A -"
                              " plane %d, " "cursor: %d\n",
                              plane_wm, cursor_wm);
                enabled |= 1;
        }

        if (g4x_compute_wm0(dev, 1,
                            &ironlake_display_wm_info,
                            ILK_LP0_PLANE_LATENCY,
                            &ironlake_cursor_wm_info,
                            ILK_LP0_CURSOR_LATENCY,
                            &plane_wm, &cursor_wm)) {
                I915_WRITE(WM0_PIPEB_ILK,
                           (plane_wm << WM0_PIPE_PLANE_SHIFT) | cursor_wm);
                DRM_DEBUG_KMS("FIFO watermarks For pipe B -"
                              " plane %d, cursor: %d\n",
                              plane_wm, cursor_wm);
                enabled |= 2;
        }

        /*
         * Calculate and update the self-refresh watermark only when one
         * display plane is used.
         */
        I915_WRITE(WM3_LP_ILK, 0);
        I915_WRITE(WM2_LP_ILK, 0);
        I915_WRITE(WM1_LP_ILK, 0);

        if (!single_plane_enabled(enabled))
                return;
        enabled = ffs(enabled) - 1;

        /* WM1 */
        if (!ironlake_compute_srwm(dev, 1, enabled,
                                   ILK_READ_WM1_LATENCY() * 500,
                                   &ironlake_display_srwm_info,
                                   &ironlake_cursor_srwm_info,
                                   &fbc_wm, &plane_wm, &cursor_wm))
                return;

        I915_WRITE(WM1_LP_ILK,
                   WM1_LP_SR_EN |
                   (ILK_READ_WM1_LATENCY() << WM1_LP_LATENCY_SHIFT) |
                   (fbc_wm << WM1_LP_FBC_SHIFT) |
                   (plane_wm << WM1_LP_SR_SHIFT) |
                   cursor_wm);

        /* WM2 */
        if (!ironlake_compute_srwm(dev, 2, enabled,
                                   ILK_READ_WM2_LATENCY() * 500,
                                   &ironlake_display_srwm_info,
                                   &ironlake_cursor_srwm_info,
                                   &fbc_wm, &plane_wm, &cursor_wm))
                return;

        I915_WRITE(WM2_LP_ILK,
                   WM2_LP_EN |
                   (ILK_READ_WM2_LATENCY() << WM1_LP_LATENCY_SHIFT) |
                   (fbc_wm << WM1_LP_FBC_SHIFT) |
                   (plane_wm << WM1_LP_SR_SHIFT) |
                   cursor_wm);

        /*
         * WM3 is unsupported on ILK, probably because we don't have latency
         * data for that power state
         */
}

static void sandybridge_update_wm(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        int latency = SNB_READ_WM0_LATENCY() * 100;     /* In unit 0.1us */
        u32 val;
        int fbc_wm, plane_wm, cursor_wm;
        unsigned int enabled;

        enabled = 0;
        if (g4x_compute_wm0(dev, 0,
                            &sandybridge_display_wm_info, latency,
                            &sandybridge_cursor_wm_info, latency,
                            &plane_wm, &cursor_wm)) {
                val = I915_READ(WM0_PIPEA_ILK);
                val &= ~(WM0_PIPE_PLANE_MASK | WM0_PIPE_CURSOR_MASK);
                I915_WRITE(WM0_PIPEA_ILK, val |
                           ((plane_wm << WM0_PIPE_PLANE_SHIFT) | cursor_wm));
                DRM_DEBUG_KMS("FIFO watermarks For pipe A -"
                              " plane %d, " "cursor: %d\n",
                              plane_wm, cursor_wm);
                enabled |= 1;
        }

        if (g4x_compute_wm0(dev, 1,
                            &sandybridge_display_wm_info, latency,
                            &sandybridge_cursor_wm_info, latency,
                            &plane_wm, &cursor_wm)) {
                val = I915_READ(WM0_PIPEB_ILK);
                val &= ~(WM0_PIPE_PLANE_MASK | WM0_PIPE_CURSOR_MASK);
                I915_WRITE(WM0_PIPEB_ILK, val |
                           ((plane_wm << WM0_PIPE_PLANE_SHIFT) | cursor_wm));
                DRM_DEBUG_KMS("FIFO watermarks For pipe B -"
                              " plane %d, cursor: %d\n",
                              plane_wm, cursor_wm);
                enabled |= 2;
        }

        if ((dev_priv->num_pipe == 3) &&
            g4x_compute_wm0(dev, 2,
                            &sandybridge_display_wm_info, latency,
                            &sandybridge_cursor_wm_info, latency,
                            &plane_wm, &cursor_wm)) {
                val = I915_READ(WM0_PIPEC_IVB);
                val &= ~(WM0_PIPE_PLANE_MASK | WM0_PIPE_CURSOR_MASK);
                I915_WRITE(WM0_PIPEC_IVB, val |
                           ((plane_wm << WM0_PIPE_PLANE_SHIFT) | cursor_wm));
                DRM_DEBUG_KMS("FIFO watermarks For pipe C -"
                              " plane %d, cursor: %d\n",
                              plane_wm, cursor_wm);
                enabled |= 3;
        }

        /*
         * Calculate and update the self-refresh watermark only when one
         * display plane is used.
         *
         * SNB support 3 levels of watermark.
         *
         * WM1/WM2/WM2 watermarks have to be enabled in the ascending order,
         * and disabled in the descending order
         *
         */
        I915_WRITE(WM3_LP_ILK, 0);
        I915_WRITE(WM2_LP_ILK, 0);
        I915_WRITE(WM1_LP_ILK, 0);

        if (!single_plane_enabled(enabled) ||
            dev_priv->sprite_scaling_enabled)
                return;
        enabled = ffs(enabled) - 1;

        /* WM1 */
        if (!ironlake_compute_srwm(dev, 1, enabled,
                                   SNB_READ_WM1_LATENCY() * 500,
                                   &sandybridge_display_srwm_info,
                                   &sandybridge_cursor_srwm_info,
                                   &fbc_wm, &plane_wm, &cursor_wm))
                return;

        I915_WRITE(WM1_LP_ILK,
                   WM1_LP_SR_EN |
                   (SNB_READ_WM1_LATENCY() << WM1_LP_LATENCY_SHIFT) |
                   (fbc_wm << WM1_LP_FBC_SHIFT) |
                   (plane_wm << WM1_LP_SR_SHIFT) |
                   cursor_wm);

        /* WM2 */
        if (!ironlake_compute_srwm(dev, 2, enabled,
                                   SNB_READ_WM2_LATENCY() * 500,
                                   &sandybridge_display_srwm_info,
                                   &sandybridge_cursor_srwm_info,
                                   &fbc_wm, &plane_wm, &cursor_wm))
                return;

        I915_WRITE(WM2_LP_ILK,
                   WM2_LP_EN |
                   (SNB_READ_WM2_LATENCY() << WM1_LP_LATENCY_SHIFT) |
                   (fbc_wm << WM1_LP_FBC_SHIFT) |
                   (plane_wm << WM1_LP_SR_SHIFT) |
                   cursor_wm);

        /* WM3 */
        if (!ironlake_compute_srwm(dev, 3, enabled,
                                   SNB_READ_WM3_LATENCY() * 500,
                                   &sandybridge_display_srwm_info,
                                   &sandybridge_cursor_srwm_info,
                                   &fbc_wm, &plane_wm, &cursor_wm))
                return;

        I915_WRITE(WM3_LP_ILK,
                   WM3_LP_EN |
                   (SNB_READ_WM3_LATENCY() << WM1_LP_LATENCY_SHIFT) |
                   (fbc_wm << WM1_LP_FBC_SHIFT) |
                   (plane_wm << WM1_LP_SR_SHIFT) |
                   cursor_wm);
}

static void
haswell_update_linetime_wm(struct drm_device *dev, int pipe,
                                 struct drm_display_mode *mode)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 temp;

        temp = I915_READ(PIPE_WM_LINETIME(pipe));
        temp &= ~PIPE_WM_LINETIME_MASK;

        /* The WM are computed with base on how long it takes to fill a single
         * row at the given clock rate, multiplied by 8.
         * */
        temp |= PIPE_WM_LINETIME_TIME(
                ((mode->crtc_hdisplay * 1000) / mode->clock) * 8);

        /* IPS watermarks are only used by pipe A, and are ignored by
         * pipes B and C.  They are calculated similarly to the common
         * linetime values, except that we are using CD clock frequency
         * in MHz instead of pixel rate for the division.
         *
         * This is a placeholder for the IPS watermark calculation code.
         */

        I915_WRITE(PIPE_WM_LINETIME(pipe), temp);
}

static bool
sandybridge_compute_sprite_wm(struct drm_device *dev, int plane,
                              uint32_t sprite_width, int pixel_size,
                              const struct intel_watermark_params *display,
                              int display_latency_ns, int *sprite_wm)
{
        struct drm_crtc *crtc;
        int clock;
        int entries, tlb_miss;

        crtc = intel_get_crtc_for_plane(dev, plane);
        if (crtc->fb == NULL || !crtc->enabled) {
                *sprite_wm = display->guard_size;
                return false;
        }

        clock = crtc->mode.clock;

        /* Use the small buffer method to calculate the sprite watermark */
        entries = ((clock * pixel_size / 1000) * display_latency_ns) / 1000;
        tlb_miss = display->fifo_size*display->cacheline_size -
                sprite_width * 8;
        if (tlb_miss > 0)
                entries += tlb_miss;
        entries = DIV_ROUND_UP(entries, display->cacheline_size);
        *sprite_wm = entries + display->guard_size;
        if (*sprite_wm > (int)display->max_wm)
                *sprite_wm = display->max_wm;

        return true;
}

static bool
sandybridge_compute_sprite_srwm(struct drm_device *dev, int plane,
                                uint32_t sprite_width, int pixel_size,
                                const struct intel_watermark_params *display,
                                int latency_ns, int *sprite_wm)
{
        struct drm_crtc *crtc;
        unsigned long line_time_us;
        int clock;
        int line_count, line_size;
        int small, large;
        int entries;

        if (!latency_ns) {
                *sprite_wm = 0;
                return false;
        }

        crtc = intel_get_crtc_for_plane(dev, plane);
        clock = crtc->mode.clock;
        if (!clock) {
                *sprite_wm = 0;
                return false;
        }

        line_time_us = (sprite_width * 1000) / clock;
        if (!line_time_us) {
                *sprite_wm = 0;
                return false;
        }

        line_count = (latency_ns / line_time_us + 1000) / 1000;
        line_size = sprite_width * pixel_size;

        /* Use the minimum of the small and large buffer method for primary */
        small = ((clock * pixel_size / 1000) * latency_ns) / 1000;
        large = line_count * line_size;

        entries = DIV_ROUND_UP(min(small, large), display->cacheline_size);
        *sprite_wm = entries + display->guard_size;

        return *sprite_wm > 0x3ff ? false : true;
}

static void sandybridge_update_sprite_wm(struct drm_device *dev, int pipe,
                                         uint32_t sprite_width, int pixel_size)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        int latency = SNB_READ_WM0_LATENCY() * 100;     /* In unit 0.1us */
        u32 val;
        int sprite_wm, reg;
        int ret;

        switch (pipe) {
        case 0:
                reg = WM0_PIPEA_ILK;
                break;
        case 1:
                reg = WM0_PIPEB_ILK;
                break;
        case 2:
                reg = WM0_PIPEC_IVB;
                break;
        default:
                return; /* bad pipe */
        }

        ret = sandybridge_compute_sprite_wm(dev, pipe, sprite_width, pixel_size,
                                            &sandybridge_display_wm_info,
                                            latency, &sprite_wm);
        if (!ret) {
                DRM_DEBUG_KMS("failed to compute sprite wm for pipe %d\n",
                              pipe);
                return;
        }

        val = I915_READ(reg);
        val &= ~WM0_PIPE_SPRITE_MASK;
        I915_WRITE(reg, val | (sprite_wm << WM0_PIPE_SPRITE_SHIFT));
        DRM_DEBUG_KMS("sprite watermarks For pipe %d - %d\n", pipe, sprite_wm);


        ret = sandybridge_compute_sprite_srwm(dev, pipe, sprite_width,
                                              pixel_size,
                                              &sandybridge_display_srwm_info,
                                              SNB_READ_WM1_LATENCY() * 500,
                                              &sprite_wm);
        if (!ret) {
                DRM_DEBUG_KMS("failed to compute sprite lp1 wm on pipe %d\n",
                              pipe);
                return;
        }
        I915_WRITE(WM1S_LP_ILK, sprite_wm);

        /* Only IVB has two more LP watermarks for sprite */
        if (!IS_IVYBRIDGE(dev))
                return;

        ret = sandybridge_compute_sprite_srwm(dev, pipe, sprite_width,
                                              pixel_size,
                                              &sandybridge_display_srwm_info,
                                              SNB_READ_WM2_LATENCY() * 500,
                                              &sprite_wm);
        if (!ret) {
                DRM_DEBUG_KMS("failed to compute sprite lp2 wm on pipe %d\n",
                              pipe);
                return;
        }
        I915_WRITE(WM2S_LP_IVB, sprite_wm);

        ret = sandybridge_compute_sprite_srwm(dev, pipe, sprite_width,
                                              pixel_size,
                                              &sandybridge_display_srwm_info,
                                              SNB_READ_WM3_LATENCY() * 500,
                                              &sprite_wm);
        if (!ret) {
                DRM_DEBUG_KMS("failed to compute sprite lp3 wm on pipe %d\n",
                              pipe);
                return;
        }
        I915_WRITE(WM3S_LP_IVB, sprite_wm);
}

/**
 * intel_update_watermarks - update FIFO watermark values based on current modes
 *
 * Calculate watermark values for the various WM regs based on current mode
 * and plane configuration.
 *
 * There are several cases to deal with here:
 *   - normal (i.e. non-self-refresh)
 *   - self-refresh (SR) mode
 *   - lines are large relative to FIFO size (buffer can hold up to 2)
 *   - lines are small relative to FIFO size (buffer can hold more than 2
 *     lines), so need to account for TLB latency
 *
 *   The normal calculation is:
 *     watermark = dotclock * bytes per pixel * latency
 *   where latency is platform & configuration dependent (we assume pessimal
 *   values here).
 *
 *   The SR calculation is:
 *     watermark = (trunc(latency/line time)+1) * surface width *
 *       bytes per pixel
 *   where
 *     line time = htotal / dotclock
 *     surface width = hdisplay for normal plane and 64 for cursor
 *   and latency is assumed to be high, as above.
 *
 * The final value programmed to the register should always be rounded up,
 * and include an extra 2 entries to account for clock crossings.
 *
 * We don't use the sprite, so we can ignore that.  And on Crestline we have
 * to set the non-SR watermarks to 8.
 */
void intel_update_watermarks(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        if (dev_priv->display.update_wm)
                dev_priv->display.update_wm(dev);
}

void intel_update_linetime_watermarks(struct drm_device *dev,
                int pipe, struct drm_display_mode *mode)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        if (dev_priv->display.update_linetime_wm)
                dev_priv->display.update_linetime_wm(dev, pipe, mode);
}

void intel_update_sprite_watermarks(struct drm_device *dev, int pipe,
                                    uint32_t sprite_width, int pixel_size)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        if (dev_priv->display.update_sprite_wm)
                dev_priv->display.update_sprite_wm(dev, pipe, sprite_width,
                                                   pixel_size);
}

static struct drm_i915_gem_object *
intel_alloc_context_page(struct drm_device *dev)
{
        struct drm_i915_gem_object *ctx;
        int ret;

        DRM_LOCK_ASSERT(dev);

        ctx = i915_gem_alloc_object(dev, 4096);
        if (!ctx) {
                DRM_DEBUG("failed to alloc power context, RC6 disabled\n");
                return NULL;
        }

        ret = i915_gem_object_pin(ctx, 4096, true);
        if (ret) {
                DRM_ERROR("failed to pin power context: %d\n", ret);
                goto err_unref;
        }

        ret = i915_gem_object_set_to_gtt_domain(ctx, 1);
        if (ret) {
                DRM_ERROR("failed to set-domain on power context: %d\n", ret);
                goto err_unpin;
        }

        return ctx;

err_unpin:
        i915_gem_object_unpin(ctx);
err_unref:
        drm_gem_object_unreference(&ctx->base);
        DRM_UNLOCK(dev);
        return NULL;
}

bool ironlake_set_drps(struct drm_device *dev, u8 val)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u16 rgvswctl;

        rgvswctl = I915_READ16(MEMSWCTL);
        if (rgvswctl & MEMCTL_CMD_STS) {
                DRM_DEBUG("gpu busy, RCS change rejected\n");
                return false; /* still busy with another command */
        }

        rgvswctl = (MEMCTL_CMD_CHFREQ << MEMCTL_CMD_SHIFT) |
                (val << MEMCTL_FREQ_SHIFT) | MEMCTL_SFCAVM;
        I915_WRITE16(MEMSWCTL, rgvswctl);
        POSTING_READ16(MEMSWCTL);

        rgvswctl |= MEMCTL_CMD_STS;
        I915_WRITE16(MEMSWCTL, rgvswctl);

        return true;
}

void ironlake_enable_drps(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 rgvmodectl = I915_READ(MEMMODECTL);
        u8 fmax, fmin, fstart, vstart;

        /* Enable temp reporting */
        I915_WRITE16(PMMISC, I915_READ(PMMISC) | MCPPCE_EN);
        I915_WRITE16(TSC1, I915_READ(TSC1) | TSE);

        /* 100ms RC evaluation intervals */
        I915_WRITE(RCUPEI, 100000);
        I915_WRITE(RCDNEI, 100000);

        /* Set max/min thresholds to 90ms and 80ms respectively */
        I915_WRITE(RCBMAXAVG, 90000);
        I915_WRITE(RCBMINAVG, 80000);

        I915_WRITE(MEMIHYST, 1);

        /* Set up min, max, and cur for interrupt handling */
        fmax = (rgvmodectl & MEMMODE_FMAX_MASK) >> MEMMODE_FMAX_SHIFT;
        fmin = (rgvmodectl & MEMMODE_FMIN_MASK);
        fstart = (rgvmodectl & MEMMODE_FSTART_MASK) >>
                MEMMODE_FSTART_SHIFT;

        vstart = (I915_READ(PXVFREQ_BASE + (fstart * 4)) & PXVFREQ_PX_MASK) >>
                PXVFREQ_PX_SHIFT;

        dev_priv->fmax = fmax; /* IPS callback will increase this */
        dev_priv->fstart = fstart;

        dev_priv->max_delay = fstart;
        dev_priv->min_delay = fmin;
        dev_priv->cur_delay = fstart;

        DRM_DEBUG_DRIVER("fmax: %d, fmin: %d, fstart: %d\n",
                         fmax, fmin, fstart);

        I915_WRITE(MEMINTREN, MEMINT_CX_SUPR_EN | MEMINT_EVAL_CHG_EN);

        /*
         * Interrupts will be enabled in ironlake_irq_postinstall
         */

        I915_WRITE(VIDSTART, vstart);
        POSTING_READ(VIDSTART);

        rgvmodectl |= MEMMODE_SWMODE_EN;
        I915_WRITE(MEMMODECTL, rgvmodectl);

        if (wait_for((I915_READ(MEMSWCTL) & MEMCTL_CMD_STS) == 0, 10))
                DRM_ERROR("stuck trying to change perf mode\n");
        pause("915dsp", 1);

        ironlake_set_drps(dev, fstart);

        dev_priv->last_count1 = I915_READ(0x112e4) + I915_READ(0x112e8) +
                I915_READ(0x112e0);
        dev_priv->last_time1 = jiffies_to_msecs(jiffies);
        dev_priv->last_count2 = I915_READ(0x112f4);
        nanotime(&dev_priv->last_time2);
}

void ironlake_disable_drps(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u16 rgvswctl = I915_READ16(MEMSWCTL);

        /* Ack interrupts, disable EFC interrupt */
        I915_WRITE(MEMINTREN, I915_READ(MEMINTREN) & ~MEMINT_EVAL_CHG_EN);
        I915_WRITE(MEMINTRSTS, MEMINT_EVAL_CHG);
        I915_WRITE(DEIER, I915_READ(DEIER) & ~DE_PCU_EVENT);
        I915_WRITE(DEIIR, DE_PCU_EVENT);
        I915_WRITE(DEIMR, I915_READ(DEIMR) | DE_PCU_EVENT);

        /* Go back to the starting frequency */
        ironlake_set_drps(dev, dev_priv->fstart);
        pause("915dsp", 1);
        rgvswctl |= MEMCTL_CMD_STS;
        I915_WRITE(MEMSWCTL, rgvswctl);
        pause("915dsp", 1);

}

void gen6_set_rps(struct drm_device *dev, u8 val)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 swreq;

        swreq = (val & 0x3ff) << 25;
        I915_WRITE(GEN6_RPNSWREQ, swreq);
}

void gen6_disable_rps(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        I915_WRITE(GEN6_RPNSWREQ, 1 << 31);
        I915_WRITE(GEN6_PMINTRMSK, 0xffffffff);
        I915_WRITE(GEN6_PMIER, 0);
        /* Complete PM interrupt masking here doesn't race with the rps work
         * item again unmasking PM interrupts because that is using a different
         * register (PMIMR) to mask PM interrupts. The only risk is in leaving
         * stale bits in PMIIR and PMIMR which gen6_enable_rps will clean up. */

        mtx_lock(&dev_priv->rps_lock);
        dev_priv->pm_iir = 0;
        mtx_unlock(&dev_priv->rps_lock);

        I915_WRITE(GEN6_PMIIR, I915_READ(GEN6_PMIIR));
}

int intel_enable_rc6(const struct drm_device *dev)
{
        /*
         * Respect the kernel parameter if it is set
         */
        if (i915_enable_rc6 >= 0)
                return i915_enable_rc6;

        /*
         * Disable RC6 on Ironlake
         */
        if (INTEL_INFO(dev)->gen == 5)
                return 0;

        /* Sorry Haswell, no RC6 for you for now. */
        if (IS_HASWELL(dev))
                return 0;

        /*
         * Disable rc6 on Sandybridge
         */
        if (INTEL_INFO(dev)->gen == 6) {
                DRM_DEBUG_DRIVER("Sandybridge: deep RC6 disabled\n");
                return INTEL_RC6_ENABLE;
        }
        DRM_DEBUG_DRIVER("RC6 and deep RC6 enabled\n");
        return (INTEL_RC6_ENABLE | INTEL_RC6p_ENABLE);
}

void gen6_enable_rps(struct drm_i915_private *dev_priv)
{
        struct intel_ring_buffer *ring;
        u32 rp_state_cap = I915_READ(GEN6_RP_STATE_CAP);
        u32 gt_perf_status = I915_READ(GEN6_GT_PERF_STATUS);
        u32 pcu_mbox, rc6_mask = 0;
        u32 gtfifodbg;
        int cur_freq, min_freq, max_freq;
        int rc6_mode;
        int i;

        /* Here begins a magic sequence of register writes to enable
         * auto-downclocking.
         *
         * Perhaps there might be some value in exposing these to
         * userspace...
         */
        I915_WRITE(GEN6_RC_STATE, 0);
        DRM_LOCK(dev_priv->dev);

        /* Clear the DBG now so we don't confuse earlier errors */
        if ((gtfifodbg = I915_READ(GTFIFODBG))) {
                DRM_ERROR("GT fifo had a previous error %x\n", gtfifodbg);
                I915_WRITE(GTFIFODBG, gtfifodbg);
        }

        gen6_gt_force_wake_get(dev_priv);

        /* disable the counters and set deterministic thresholds */
        I915_WRITE(GEN6_RC_CONTROL, 0);

        I915_WRITE(GEN6_RC1_WAKE_RATE_LIMIT, 1000 << 16);
        I915_WRITE(GEN6_RC6_WAKE_RATE_LIMIT, 40 << 16 | 30);
        I915_WRITE(GEN6_RC6pp_WAKE_RATE_LIMIT, 30);
        I915_WRITE(GEN6_RC_EVALUATION_INTERVAL, 125000);
        I915_WRITE(GEN6_RC_IDLE_HYSTERSIS, 25);

        for_each_ring(ring, dev_priv, i)
                I915_WRITE(RING_MAX_IDLE(ring->mmio_base), 10);

        I915_WRITE(GEN6_RC_SLEEP, 0);
        I915_WRITE(GEN6_RC1e_THRESHOLD, 1000);
        I915_WRITE(GEN6_RC6_THRESHOLD, 50000);
        I915_WRITE(GEN6_RC6p_THRESHOLD, 100000);
        I915_WRITE(GEN6_RC6pp_THRESHOLD, 64000); /* unused */

        rc6_mode = intel_enable_rc6(dev_priv->dev);
        if (rc6_mode & INTEL_RC6_ENABLE)
                rc6_mask |= GEN6_RC_CTL_RC6_ENABLE;

        if (rc6_mode & INTEL_RC6p_ENABLE)
                rc6_mask |= GEN6_RC_CTL_RC6p_ENABLE;

        if (rc6_mode & INTEL_RC6pp_ENABLE)
                rc6_mask |= GEN6_RC_CTL_RC6pp_ENABLE;

        DRM_INFO("Enabling RC6 states: RC6 %s, RC6p %s, RC6pp %s\n",
                        (rc6_mode & INTEL_RC6_ENABLE) ? "on" : "off",
                        (rc6_mode & INTEL_RC6p_ENABLE) ? "on" : "off",
                        (rc6_mode & INTEL_RC6pp_ENABLE) ? "on" : "off");

        I915_WRITE(GEN6_RC_CONTROL,
                   rc6_mask |
                   GEN6_RC_CTL_EI_MODE(1) |
                   GEN6_RC_CTL_HW_ENABLE);

        I915_WRITE(GEN6_RPNSWREQ,
                   GEN6_FREQUENCY(10) |
                   GEN6_OFFSET(0) |
                   GEN6_AGGRESSIVE_TURBO);
        I915_WRITE(GEN6_RC_VIDEO_FREQ,
                   GEN6_FREQUENCY(12));

        I915_WRITE(GEN6_RP_DOWN_TIMEOUT, 1000000);
        I915_WRITE(GEN6_RP_INTERRUPT_LIMITS,
                   18 << 24 |
                   6 << 16);
        I915_WRITE(GEN6_RP_UP_THRESHOLD, 10000);
        I915_WRITE(GEN6_RP_DOWN_THRESHOLD, 1000000);
        I915_WRITE(GEN6_RP_UP_EI, 100000);
        I915_WRITE(GEN6_RP_DOWN_EI, 5000000);
        I915_WRITE(GEN6_RP_IDLE_HYSTERSIS, 10);
        I915_WRITE(GEN6_RP_CONTROL,
                   GEN6_RP_MEDIA_TURBO |
                   GEN6_RP_MEDIA_HW_MODE |
                   GEN6_RP_MEDIA_IS_GFX |
                   GEN6_RP_ENABLE |
                   GEN6_RP_UP_BUSY_AVG |
                   GEN6_RP_DOWN_IDLE_CONT);

        if (wait_for((I915_READ(GEN6_PCODE_MAILBOX) & GEN6_PCODE_READY) == 0,
                     500))
                DRM_ERROR("timeout waiting for pcode mailbox to become idle\n");

        I915_WRITE(GEN6_PCODE_DATA, 0);
        I915_WRITE(GEN6_PCODE_MAILBOX,
                   GEN6_PCODE_READY |
                   GEN6_PCODE_WRITE_MIN_FREQ_TABLE);
        if (wait_for((I915_READ(GEN6_PCODE_MAILBOX) & GEN6_PCODE_READY) == 0,
                     500))
                DRM_ERROR("timeout waiting for pcode mailbox to finish\n");

        min_freq = (rp_state_cap & 0xff0000) >> 16;
        max_freq = rp_state_cap & 0xff;
        cur_freq = (gt_perf_status & 0xff00) >> 8;

        /* Check for overclock support */
        if (wait_for((I915_READ(GEN6_PCODE_MAILBOX) & GEN6_PCODE_READY) == 0,
                     500))
                DRM_ERROR("timeout waiting for pcode mailbox to become idle\n");
        I915_WRITE(GEN6_PCODE_MAILBOX, GEN6_READ_OC_PARAMS);
        pcu_mbox = I915_READ(GEN6_PCODE_DATA);
        if (wait_for((I915_READ(GEN6_PCODE_MAILBOX) & GEN6_PCODE_READY) == 0,
                     500))
                DRM_ERROR("timeout waiting for pcode mailbox to finish\n");
        if (pcu_mbox & (1<<31)) { /* OC supported */
                max_freq = pcu_mbox & 0xff;
                DRM_DEBUG_DRIVER("overclocking supported, adjusting frequency max to %dMHz\n", pcu_mbox * 50);
        }

        /* In units of 100MHz */
        dev_priv->max_delay = max_freq;
        dev_priv->min_delay = min_freq;
        dev_priv->cur_delay = cur_freq;

        /* requires MSI enabled */
        I915_WRITE(GEN6_PMIER,
                   GEN6_PM_MBOX_EVENT |
                   GEN6_PM_THERMAL_EVENT |
                   GEN6_PM_RP_DOWN_TIMEOUT |
                   GEN6_PM_RP_UP_THRESHOLD |
                   GEN6_PM_RP_DOWN_THRESHOLD |
                   GEN6_PM_RP_UP_EI_EXPIRED |
                   GEN6_PM_RP_DOWN_EI_EXPIRED);
        mtx_lock(&dev_priv->rps_lock);
        if (dev_priv->pm_iir != 0)
                printf("KMS: pm_iir %x\n", dev_priv->pm_iir);
        I915_WRITE(GEN6_PMIMR, 0);
        mtx_unlock(&dev_priv->rps_lock);
        /* enable all PM interrupts */
        I915_WRITE(GEN6_PMINTRMSK, 0);

        gen6_gt_force_wake_put(dev_priv);
        DRM_UNLOCK(dev_priv->dev);
}

void gen6_update_ring_freq(struct drm_i915_private *dev_priv)
{
        int min_freq = 15;
        int gpu_freq, ia_freq, max_ia_freq;
        int scaling_factor = 180;
        uint64_t tsc_freq;

#if 0
        max_ia_freq = cpufreq_quick_get_max(0);
        /*
         * Default to measured freq if none found, PCU will ensure we don't go
         * over
         */
        if (!max_ia_freq)
                max_ia_freq = tsc_khz;

        /* Convert from kHz to MHz */
        max_ia_freq /= 1000;
#else
        tsc_freq = atomic_load_acq_64(&tsc_freq);
        max_ia_freq = tsc_freq / 1000 / 1000;
#endif

        DRM_LOCK(dev_priv->dev);

        /*
         * For each potential GPU frequency, load a ring frequency we'd like
         * to use for memory access.  We do this by specifying the IA frequency
         * the PCU should use as a reference to determine the ring frequency.
         */
        for (gpu_freq = dev_priv->max_delay; gpu_freq >= dev_priv->min_delay;
             gpu_freq--) {
                int diff = dev_priv->max_delay - gpu_freq;
                int d;

                /*
                 * For GPU frequencies less than 750MHz, just use the lowest
                 * ring freq.
                 */
                if (gpu_freq < min_freq)
                        ia_freq = 800;
                else
                        ia_freq = max_ia_freq - ((diff * scaling_factor) / 2);
                d = 100;
                ia_freq = (ia_freq + d / 2) / d;

                I915_WRITE(GEN6_PCODE_DATA,
                           (ia_freq << GEN6_PCODE_FREQ_IA_RATIO_SHIFT) |
                           gpu_freq);
                I915_WRITE(GEN6_PCODE_MAILBOX, GEN6_PCODE_READY |
                           GEN6_PCODE_WRITE_MIN_FREQ_TABLE);
                if (wait_for((I915_READ(GEN6_PCODE_MAILBOX) &
                              GEN6_PCODE_READY) == 0, 10)) {
                        DRM_ERROR("pcode write of freq table timed out\n");
                        continue;
                }
        }

        DRM_UNLOCK(dev_priv->dev);
}

static void ironlake_teardown_rc6(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        if (dev_priv->renderctx) {
                i915_gem_object_unpin(dev_priv->renderctx);
                drm_gem_object_unreference(&dev_priv->renderctx->base);
                dev_priv->renderctx = NULL;
        }

        if (dev_priv->pwrctx) {
                i915_gem_object_unpin(dev_priv->pwrctx);
                drm_gem_object_unreference(&dev_priv->pwrctx->base);
                dev_priv->pwrctx = NULL;
        }
}

void ironlake_disable_rc6(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        if (I915_READ(PWRCTXA)) {
                /* Wake the GPU, prevent RC6, then restore RSTDBYCTL */
                I915_WRITE(RSTDBYCTL, I915_READ(RSTDBYCTL) | RCX_SW_EXIT);
                wait_for(((I915_READ(RSTDBYCTL) & RSX_STATUS_MASK) == RSX_STATUS_ON),
                         50);

                I915_WRITE(PWRCTXA, 0);
                POSTING_READ(PWRCTXA);

                I915_WRITE(RSTDBYCTL, I915_READ(RSTDBYCTL) & ~RCX_SW_EXIT);
                POSTING_READ(RSTDBYCTL);
        }

        ironlake_teardown_rc6(dev);
}

static int ironlake_setup_rc6(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        if (dev_priv->renderctx == NULL)
                dev_priv->renderctx = intel_alloc_context_page(dev);
        if (!dev_priv->renderctx)
                return -ENOMEM;

        if (dev_priv->pwrctx == NULL)
                dev_priv->pwrctx = intel_alloc_context_page(dev);
        if (!dev_priv->pwrctx) {
                ironlake_teardown_rc6(dev);
                return -ENOMEM;
        }

        return 0;
}

void ironlake_enable_rc6(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct intel_ring_buffer *ring = &dev_priv->rings[RCS];
        int ret;

        /* rc6 disabled by default due to repeated reports of hanging during
         * boot and resume.
         */
        if (!intel_enable_rc6(dev))
                return;

        DRM_LOCK(dev);
        ret = ironlake_setup_rc6(dev);
        if (ret) {
                DRM_UNLOCK(dev);
                return;
        }

        /*
         * GPU can automatically power down the render unit if given a page
         * to save state.
         */
        ret = intel_ring_begin(ring, 6);
        if (ret) {
                ironlake_teardown_rc6(dev);
                DRM_UNLOCK(dev);
                return;
        }

        intel_ring_emit(ring, MI_SUSPEND_FLUSH | MI_SUSPEND_FLUSH_EN);
        intel_ring_emit(ring, MI_SET_CONTEXT);
        intel_ring_emit(ring, dev_priv->renderctx->gtt_offset |
                        MI_MM_SPACE_GTT |
                        MI_SAVE_EXT_STATE_EN |
                        MI_RESTORE_EXT_STATE_EN |
                        MI_RESTORE_INHIBIT);
        intel_ring_emit(ring, MI_SUSPEND_FLUSH);
        intel_ring_emit(ring, MI_NOOP);
        intel_ring_emit(ring, MI_FLUSH);
        intel_ring_advance(ring);

        /*
         * Wait for the command parser to advance past MI_SET_CONTEXT. The HW
         * does an implicit flush, combined with MI_FLUSH above, it should be
         * safe to assume that renderctx is valid
         */
        ret = intel_wait_ring_idle(ring);
        if (ret) {
                DRM_ERROR("failed to enable ironlake power power savings\n");
                ironlake_teardown_rc6(dev);
                DRM_UNLOCK(dev);
                return;
        }

        I915_WRITE(PWRCTXA, dev_priv->pwrctx->gtt_offset | PWRCTX_EN);
        I915_WRITE(RSTDBYCTL, I915_READ(RSTDBYCTL) & ~RCX_SW_EXIT);
        DRM_UNLOCK(dev);
}

static unsigned long intel_pxfreq(u32 vidfreq)
{
        unsigned long freq;
        int div = (vidfreq & 0x3f0000) >> 16;
        int post = (vidfreq & 0x3000) >> 12;
        int pre = (vidfreq & 0x7);

        if (!pre)
                return 0;

        freq = ((div * 133333) / ((1<<post) * pre));

        return freq;
}

static const struct cparams {
        u16 i;
        u16 t;
        u16 m;
        u16 c;
} cparams[] = {
        { 1, 1333, 301, 28664 },
        { 1, 1066, 294, 24460 },
        { 1, 800, 294, 25192 },
        { 0, 1333, 276, 27605 },
        { 0, 1066, 276, 27605 },
        { 0, 800, 231, 23784 },
};

unsigned long i915_chipset_val(struct drm_i915_private *dev_priv)
{
        u64 total_count, diff, ret;
        u32 count1, count2, count3, m = 0, c = 0;
        unsigned long now = jiffies_to_msecs(jiffies), diff1;
        int i;

        diff1 = now - dev_priv->last_time1;
        /*
         * sysctl(8) reads the value of sysctl twice in rapid
         * succession.  There is high chance that it happens in the
         * same timer tick.  Use the cached value to not divide by
         * zero and give the hw a chance to gather more samples.
         */
        if (diff1 <= 10)
                return (dev_priv->chipset_power);

        count1 = I915_READ(DMIEC);
        count2 = I915_READ(DDREC);
        count3 = I915_READ(CSIEC);

        total_count = count1 + count2 + count3;

        /* FIXME: handle per-counter overflow */
        if (total_count < dev_priv->last_count1) {
                diff = ~0UL - dev_priv->last_count1;
                diff += total_count;
        } else {
                diff = total_count - dev_priv->last_count1;
        }

        for (i = 0; i < DRM_ARRAY_SIZE(cparams); i++) {
                if (cparams[i].i == dev_priv->c_m &&
                    cparams[i].t == dev_priv->r_t) {
                        m = cparams[i].m;
                        c = cparams[i].c;
                        break;
                }
        }

        diff = diff / diff1;
        ret = ((m * diff) + c);
        ret = ret / 10;

        dev_priv->last_count1 = total_count;
        dev_priv->last_time1 = now;

        dev_priv->chipset_power = ret;
        return (ret);
}

unsigned long i915_mch_val(struct drm_i915_private *dev_priv)
{
        unsigned long m, x, b;
        u32 tsfs;

        tsfs = I915_READ(TSFS);

        m = ((tsfs & TSFS_SLOPE_MASK) >> TSFS_SLOPE_SHIFT);
        x = I915_READ8(I915_TR1);

        b = tsfs & TSFS_INTR_MASK;

        return ((m * x) / 127) - b;
}

static u16 pvid_to_extvid(struct drm_i915_private *dev_priv, u8 pxvid)
{
        static const struct v_table {
                u16 vd; /* in .1 mil */
                u16 vm; /* in .1 mil */
        } v_table[] = {
                { 0, 0, },
                { 375, 0, },
                { 500, 0, },
                { 625, 0, },
                { 750, 0, },
                { 875, 0, },
                { 1000, 0, },
                { 1125, 0, },
                { 4125, 3000, },
                { 4125, 3000, },
                { 4125, 3000, },
                { 4125, 3000, },
                { 4125, 3000, },
                { 4125, 3000, },
                { 4125, 3000, },
                { 4125, 3000, },
                { 4125, 3000, },
                { 4125, 3000, },
                { 4125, 3000, },
                { 4125, 3000, },
                { 4125, 3000, },
                { 4125, 3000, },
                { 4125, 3000, },
                { 4125, 3000, },
                { 4125, 3000, },
                { 4125, 3000, },
                { 4125, 3000, },
                { 4125, 3000, },
                { 4125, 3000, },
                { 4125, 3000, },
                { 4125, 3000, },
                { 4125, 3000, },
                { 4250, 3125, },
                { 4375, 3250, },
                { 4500, 3375, },
                { 4625, 3500, },
                { 4750, 3625, },
                { 4875, 3750, },
                { 5000, 3875, },
                { 5125, 4000, },
                { 5250, 4125, },
                { 5375, 4250, },
                { 5500, 4375, },
                { 5625, 4500, },
                { 5750, 4625, },
                { 5875, 4750, },
                { 6000, 4875, },
                { 6125, 5000, },
                { 6250, 5125, },
                { 6375, 5250, },
                { 6500, 5375, },
                { 6625, 5500, },
                { 6750, 5625, },
                { 6875, 5750, },
                { 7000, 5875, },
                { 7125, 6000, },
                { 7250, 6125, },
                { 7375, 6250, },
                { 7500, 6375, },
                { 7625, 6500, },
                { 7750, 6625, },
                { 7875, 6750, },
                { 8000, 6875, },
                { 8125, 7000, },
                { 8250, 7125, },
                { 8375, 7250, },
                { 8500, 7375, },
                { 8625, 7500, },
                { 8750, 7625, },
                { 8875, 7750, },
                { 9000, 7875, },
                { 9125, 8000, },
                { 9250, 8125, },
                { 9375, 8250, },
                { 9500, 8375, },
                { 9625, 8500, },
                { 9750, 8625, },
                { 9875, 8750, },
                { 10000, 8875, },
                { 10125, 9000, },
                { 10250, 9125, },
                { 10375, 9250, },
                { 10500, 9375, },
                { 10625, 9500, },
                { 10750, 9625, },
                { 10875, 9750, },
                { 11000, 9875, },
                { 11125, 10000, },
                { 11250, 10125, },
                { 11375, 10250, },
                { 11500, 10375, },
                { 11625, 10500, },
                { 11750, 10625, },
                { 11875, 10750, },
                { 12000, 10875, },
                { 12125, 11000, },
                { 12250, 11125, },
                { 12375, 11250, },
                { 12500, 11375, },
                { 12625, 11500, },
                { 12750, 11625, },
                { 12875, 11750, },
                { 13000, 11875, },
                { 13125, 12000, },
                { 13250, 12125, },
                { 13375, 12250, },
                { 13500, 12375, },
                { 13625, 12500, },
                { 13750, 12625, },
                { 13875, 12750, },
                { 14000, 12875, },
                { 14125, 13000, },
                { 14250, 13125, },
                { 14375, 13250, },
                { 14500, 13375, },
                { 14625, 13500, },
                { 14750, 13625, },
                { 14875, 13750, },
                { 15000, 13875, },
                { 15125, 14000, },
                { 15250, 14125, },
                { 15375, 14250, },
                { 15500, 14375, },
                { 15625, 14500, },
                { 15750, 14625, },
                { 15875, 14750, },
                { 16000, 14875, },
                { 16125, 15000, },
        };
        if (dev_priv->info->is_mobile)
                return v_table[pxvid].vm;
        else
                return v_table[pxvid].vd;
}

void i915_update_gfx_val(struct drm_i915_private *dev_priv)
{
        struct timespec now, diff1;
        u64 diff;
        unsigned long diffms;
        u32 count;

        if (dev_priv->info->gen != 5)
                return;

        nanotime(&now);
        diff1 = now;
        timespecsub(&diff1, &dev_priv->last_time2);

        /* Don't divide by 0 */
        diffms = diff1.tv_sec * 1000 + diff1.tv_nsec / 1000000;
        if (!diffms)
                return;

        count = I915_READ(GFXEC);

        if (count < dev_priv->last_count2) {
                diff = ~0UL - dev_priv->last_count2;
                diff += count;
        } else {
                diff = count - dev_priv->last_count2;
        }

        dev_priv->last_count2 = count;
        dev_priv->last_time2 = now;

        /* More magic constants... */
        diff = diff * 1181;
        diff = diff / (diffms * 10);
        dev_priv->gfx_power = diff;
}

unsigned long i915_gfx_val(struct drm_i915_private *dev_priv)
{
        unsigned long t, corr, state1, corr2, state2;
        u32 pxvid, ext_v;

        pxvid = I915_READ(PXVFREQ_BASE + (dev_priv->cur_delay * 4));
        pxvid = (pxvid >> 24) & 0x7f;
        ext_v = pvid_to_extvid(dev_priv, pxvid);

        state1 = ext_v;

        t = i915_mch_val(dev_priv);

        /* Revel in the empirically derived constants */

        /* Correction factor in 1/100000 units */
        if (t > 80)
                corr = ((t * 2349) + 135940);
        else if (t >= 50)
                corr = ((t * 964) + 29317);
        else /* < 50 */
                corr = ((t * 301) + 1004);

        corr = corr * ((150142 * state1) / 10000 - 78642);
        corr /= 100000;
        corr2 = (corr * dev_priv->corr);

        state2 = (corr2 * state1) / 10000;
        state2 /= 100; /* convert to mW */

        i915_update_gfx_val(dev_priv);

        return dev_priv->gfx_power + state2;
}

/**
 * i915_read_mch_val - return value for IPS use
 *
 * Calculate and return a value for the IPS driver to use when deciding whether
 * we have thermal and power headroom to increase CPU or GPU power budget.
 */
unsigned long i915_read_mch_val(void)
{
        struct drm_i915_private *dev_priv;
        unsigned long chipset_val, graphics_val, ret = 0;

        mtx_lock(&mchdev_lock);
        if (!i915_mch_dev)
                goto out_unlock;
        dev_priv = i915_mch_dev;

        chipset_val = i915_chipset_val(dev_priv);
        graphics_val = i915_gfx_val(dev_priv);

        ret = chipset_val + graphics_val;

out_unlock:
        mtx_unlock(&mchdev_lock);

        return ret;
}

/**
 * i915_gpu_raise - raise GPU frequency limit
 *
 * Raise the limit; IPS indicates we have thermal headroom.
 */
bool i915_gpu_raise(void)
{
        struct drm_i915_private *dev_priv;
        bool ret = true;

        mtx_lock(&mchdev_lock);
        if (!i915_mch_dev) {
                ret = false;
                goto out_unlock;
        }
        dev_priv = i915_mch_dev;

        if (dev_priv->max_delay > dev_priv->fmax)
                dev_priv->max_delay--;

out_unlock:
        mtx_unlock(&mchdev_lock);

        return ret;
}

/**
 * i915_gpu_lower - lower GPU frequency limit
 *
 * IPS indicates we're close to a thermal limit, so throttle back the GPU
 * frequency maximum.
 */
bool i915_gpu_lower(void)
{
        struct drm_i915_private *dev_priv;
        bool ret = true;

        mtx_lock(&mchdev_lock);
        if (!i915_mch_dev) {
                ret = false;
                goto out_unlock;
        }
        dev_priv = i915_mch_dev;

        if (dev_priv->max_delay < dev_priv->min_delay)
                dev_priv->max_delay++;

out_unlock:
        mtx_unlock(&mchdev_lock);

        return ret;
}

/**
 * i915_gpu_busy - indicate GPU business to IPS
 *
 * Tell the IPS driver whether or not the GPU is busy.
 */
bool i915_gpu_busy(void)
{
        struct drm_i915_private *dev_priv;
        bool ret = false;

        mtx_lock(&mchdev_lock);
        if (!i915_mch_dev)
                goto out_unlock;
        dev_priv = i915_mch_dev;

        ret = dev_priv->busy;

out_unlock:
        mtx_unlock(&mchdev_lock);

        return ret;
}

/**
 * i915_gpu_turbo_disable - disable graphics turbo
 *
 * Disable graphics turbo by resetting the max frequency and setting the
 * current frequency to the default.
 */
bool i915_gpu_turbo_disable(void)
{
        struct drm_i915_private *dev_priv;
        bool ret = true;

        mtx_lock(&mchdev_lock);
        if (!i915_mch_dev) {
                ret = false;
                goto out_unlock;
        }
        dev_priv = i915_mch_dev;

        dev_priv->max_delay = dev_priv->fstart;

        if (!ironlake_set_drps(dev_priv->dev, dev_priv->fstart))
                ret = false;

out_unlock:
        mtx_unlock(&mchdev_lock);

        return ret;
}

void intel_gpu_ips_init(struct drm_i915_private *dev_priv)
{
        mtx_lock(&mchdev_lock);
        i915_mch_dev = dev_priv;
        dev_priv->mchdev_lock = &mchdev_lock;
        mtx_unlock(&mchdev_lock);

#if 0
        ips_ping_for_i915_load();
#endif
}

void intel_gpu_ips_teardown(void)
{
        mtx_lock(&mchdev_lock);
        i915_mch_dev = NULL;
        mtx_unlock(&mchdev_lock);
}

void intel_init_emon(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 lcfuse;
        u8 pxw[16];
        int i;

        /* Disable to program */
        I915_WRITE(ECR, 0);
        POSTING_READ(ECR);

        /* Program energy weights for various events */
        I915_WRITE(SDEW, 0x15040d00);
        I915_WRITE(CSIEW0, 0x007f0000);
        I915_WRITE(CSIEW1, 0x1e220004);
        I915_WRITE(CSIEW2, 0x04000004);

        for (i = 0; i < 5; i++)
                I915_WRITE(PEW + (i * 4), 0);
        for (i = 0; i < 3; i++)
                I915_WRITE(DEW + (i * 4), 0);

        /* Program P-state weights to account for frequency power adjustment */
        for (i = 0; i < 16; i++) {
                u32 pxvidfreq = I915_READ(PXVFREQ_BASE + (i * 4));
                unsigned long freq = intel_pxfreq(pxvidfreq);
                unsigned long vid = (pxvidfreq & PXVFREQ_PX_MASK) >>
                        PXVFREQ_PX_SHIFT;
                unsigned long val;

                val = vid * vid;
                val *= (freq / 1000);
                val *= 255;
                val /= (127*127*900);
                if (val > 0xff)
                        DRM_ERROR("bad pxval: %ld\n", val);
                pxw[i] = val;
        }
        /* Render standby states get 0 weight */
        pxw[14] = 0;
        pxw[15] = 0;

        for (i = 0; i < 4; i++) {
                u32 val = (pxw[i*4] << 24) | (pxw[(i*4)+1] << 16) |
                        (pxw[(i*4)+2] << 8) | (pxw[(i*4)+3]);
                I915_WRITE(PXW + (i * 4), val);
        }

        /* Adjust magic regs to magic values (more experimental results) */
        I915_WRITE(OGW0, 0);
        I915_WRITE(OGW1, 0);
        I915_WRITE(EG0, 0x00007f00);
        I915_WRITE(EG1, 0x0000000e);
        I915_WRITE(EG2, 0x000e0000);
        I915_WRITE(EG3, 0x68000300);
        I915_WRITE(EG4, 0x42000000);
        I915_WRITE(EG5, 0x00140031);
        I915_WRITE(EG6, 0);
        I915_WRITE(EG7, 0);

        for (i = 0; i < 8; i++)
                I915_WRITE(PXWL + (i * 4), 0);

        /* Enable PMON + select events */
        I915_WRITE(ECR, 0x80000019);

        lcfuse = I915_READ(LCFUSE02);

        dev_priv->corr = (lcfuse & LCFUSE_HIV_MASK);
}

static void ironlake_init_clock_gating(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        uint32_t dspclk_gate = VRHUNIT_CLOCK_GATE_DISABLE;

        /* Required for FBC */
        dspclk_gate |= DPFCUNIT_CLOCK_GATE_DISABLE |
                DPFCRUNIT_CLOCK_GATE_DISABLE |
                DPFDUNIT_CLOCK_GATE_DISABLE;
        /* Required for CxSR */
        dspclk_gate |= DPARBUNIT_CLOCK_GATE_DISABLE;

        I915_WRITE(PCH_3DCGDIS0,
                   MARIUNIT_CLOCK_GATE_DISABLE |
                   SVSMUNIT_CLOCK_GATE_DISABLE);
        I915_WRITE(PCH_3DCGDIS1,
                   VFMUNIT_CLOCK_GATE_DISABLE);

        I915_WRITE(PCH_DSPCLK_GATE_D, dspclk_gate);

        /*
         * According to the spec the following bits should be set in
         * order to enable memory self-refresh
         * The bit 22/21 of 0x42004
         * The bit 5 of 0x42020
         * The bit 15 of 0x45000
         */
        I915_WRITE(ILK_DISPLAY_CHICKEN2,
                   (I915_READ(ILK_DISPLAY_CHICKEN2) |
                    ILK_DPARB_GATE | ILK_VSDPFD_FULL));
        I915_WRITE(ILK_DSPCLK_GATE,
                   (I915_READ(ILK_DSPCLK_GATE) |
                    ILK_DPARB_CLK_GATE));
        I915_WRITE(DISP_ARB_CTL,
                   (I915_READ(DISP_ARB_CTL) |
                    DISP_FBC_WM_DIS));
        I915_WRITE(WM3_LP_ILK, 0);
        I915_WRITE(WM2_LP_ILK, 0);
        I915_WRITE(WM1_LP_ILK, 0);

        /*
         * Based on the document from hardware guys the following bits
         * should be set unconditionally in order to enable FBC.
         * The bit 22 of 0x42000
         * The bit 22 of 0x42004
         * The bit 7,8,9 of 0x42020.
         */
        if (IS_IRONLAKE_M(dev)) {
                I915_WRITE(ILK_DISPLAY_CHICKEN1,
                           I915_READ(ILK_DISPLAY_CHICKEN1) |
                           ILK_FBCQ_DIS);
                I915_WRITE(ILK_DISPLAY_CHICKEN2,
                           I915_READ(ILK_DISPLAY_CHICKEN2) |
                           ILK_DPARB_GATE);
                I915_WRITE(ILK_DSPCLK_GATE,
                           I915_READ(ILK_DSPCLK_GATE) |
                           ILK_DPFC_DIS1 |
                           ILK_DPFC_DIS2 |
                           ILK_CLK_FBC);
        }

        I915_WRITE(ILK_DISPLAY_CHICKEN2,
                   I915_READ(ILK_DISPLAY_CHICKEN2) |
                   ILK_ELPIN_409_SELECT);
        I915_WRITE(_3D_CHICKEN2,
                   _3D_CHICKEN2_WM_READ_PIPELINED << 16 |
                   _3D_CHICKEN2_WM_READ_PIPELINED);
}

static void gen6_init_clock_gating(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        int pipe;
        uint32_t dspclk_gate = VRHUNIT_CLOCK_GATE_DISABLE;

        I915_WRITE(PCH_DSPCLK_GATE_D, dspclk_gate);

        I915_WRITE(ILK_DISPLAY_CHICKEN2,
                   I915_READ(ILK_DISPLAY_CHICKEN2) |
                   ILK_ELPIN_409_SELECT);

        I915_WRITE(WM3_LP_ILK, 0);
        I915_WRITE(WM2_LP_ILK, 0);
        I915_WRITE(WM1_LP_ILK, 0);

        I915_WRITE(CACHE_MODE_0,
                   _MASKED_BIT_DISABLE(CM0_STC_EVICT_DISABLE_LRA_SNB));

        I915_WRITE(GEN6_UCGCTL1,
                   I915_READ(GEN6_UCGCTL1) |
                   GEN6_BLBUNIT_CLOCK_GATE_DISABLE |
                   GEN6_CSUNIT_CLOCK_GATE_DISABLE);

        /* According to the BSpec vol1g, bit 12 (RCPBUNIT) clock
         * gating disable must be set.  Failure to set it results in
         * flickering pixels due to Z write ordering failures after
         * some amount of runtime in the Mesa "fire" demo, and Unigine
         * Sanctuary and Tropics, and apparently anything else with
         * alpha test or pixel discard.
         *
         * According to the spec, bit 11 (RCCUNIT) must also be set,
         * but we didn't debug actual testcases to find it out.
         */
        I915_WRITE(GEN6_UCGCTL2,
                   GEN6_RCPBUNIT_CLOCK_GATE_DISABLE |
                   GEN6_RCCUNIT_CLOCK_GATE_DISABLE);

        /* Bspec says we need to always set all mask bits. */
        I915_WRITE(_3D_CHICKEN, (0xFFFF << 16) |
                   _3D_CHICKEN_SF_DISABLE_FASTCLIP_CULL);

        /*
         * According to the spec the following bits should be
         * set in order to enable memory self-refresh and fbc:
         * The bit21 and bit22 of 0x42000
         * The bit21 and bit22 of 0x42004
         * The bit5 and bit7 of 0x42020
         * The bit14 of 0x70180
         * The bit14 of 0x71180
         */
        I915_WRITE(ILK_DISPLAY_CHICKEN1,
                   I915_READ(ILK_DISPLAY_CHICKEN1) |
                   ILK_FBCQ_DIS | ILK_PABSTRETCH_DIS);
        I915_WRITE(ILK_DISPLAY_CHICKEN2,
                   I915_READ(ILK_DISPLAY_CHICKEN2) |
                   ILK_DPARB_GATE | ILK_VSDPFD_FULL);
        I915_WRITE(ILK_DSPCLK_GATE,
                   I915_READ(ILK_DSPCLK_GATE) |
                   ILK_DPARB_CLK_GATE  |
                   ILK_DPFD_CLK_GATE);

        for_each_pipe(pipe) {
                I915_WRITE(DSPCNTR(pipe),
                           I915_READ(DSPCNTR(pipe)) |
                           DISPPLANE_TRICKLE_FEED_DISABLE);
                intel_flush_display_plane(dev_priv, pipe);
        }
}

static void gen7_setup_fixed_func_scheduler(struct drm_i915_private *dev_priv)
{
        uint32_t reg = I915_READ(GEN7_FF_THREAD_MODE);

        reg &= ~GEN7_FF_SCHED_MASK;
        reg |= GEN7_FF_TS_SCHED_HW;
        reg |= GEN7_FF_VS_SCHED_HW;
        reg |= GEN7_FF_DS_SCHED_HW;

        I915_WRITE(GEN7_FF_THREAD_MODE, reg);
}

static void ivybridge_init_clock_gating(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        int pipe;
        uint32_t dspclk_gate = VRHUNIT_CLOCK_GATE_DISABLE;

        I915_WRITE(PCH_DSPCLK_GATE_D, dspclk_gate);

        I915_WRITE(WM3_LP_ILK, 0);
        I915_WRITE(WM2_LP_ILK, 0);
        I915_WRITE(WM1_LP_ILK, 0);

        /* According to the spec, bit 13 (RCZUNIT) must be set on IVB.
         * This implements the WaDisableRCZUnitClockGating workaround.
         */
        I915_WRITE(GEN6_UCGCTL2, GEN6_RCZUNIT_CLOCK_GATE_DISABLE);

        I915_WRITE(ILK_DSPCLK_GATE, IVB_VRHUNIT_CLK_GATE);

        I915_WRITE(IVB_CHICKEN3,
                   CHICKEN3_DGMG_REQ_OUT_FIX_DISABLE |
                   CHICKEN3_DGMG_DONE_FIX_DISABLE);

        /* Apply the WaDisableRHWOOptimizationForRenderHang workaround. */
        I915_WRITE(GEN7_COMMON_SLICE_CHICKEN1,
                   GEN7_CSC1_RHWO_OPT_DISABLE_IN_RCC);

        /* WaApplyL3ControlAndL3ChickenMode requires those two on Ivy Bridge */
        I915_WRITE(GEN7_L3CNTLREG1,
                        GEN7_WA_FOR_GEN7_L3_CONTROL);
        I915_WRITE(GEN7_L3_CHICKEN_MODE_REGISTER,
                        GEN7_WA_L3_CHICKEN_MODE);

        /* This is required by WaCatErrorRejectionIssue */
        I915_WRITE(GEN7_SQ_CHICKEN_MBCUNIT_CONFIG,
                        I915_READ(GEN7_SQ_CHICKEN_MBCUNIT_CONFIG) |
                        GEN7_SQ_CHICKEN_MBCUNIT_SQINTMOB);

        for_each_pipe(pipe) {
                I915_WRITE(DSPCNTR(pipe),
                           I915_READ(DSPCNTR(pipe)) |
                           DISPPLANE_TRICKLE_FEED_DISABLE);
                intel_flush_display_plane(dev_priv, pipe);
        }

        gen7_setup_fixed_func_scheduler(dev_priv);

        /* WaDisable4x2SubspanOptimization */
        I915_WRITE(CACHE_MODE_1,
                   _MASKED_BIT_ENABLE(PIXEL_SUBSPAN_COLLECT_OPT_DISABLE));
}

static void valleyview_init_clock_gating(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        int pipe;
        uint32_t dspclk_gate = VRHUNIT_CLOCK_GATE_DISABLE;

        I915_WRITE(PCH_DSPCLK_GATE_D, dspclk_gate);

        I915_WRITE(WM3_LP_ILK, 0);
        I915_WRITE(WM2_LP_ILK, 0);
        I915_WRITE(WM1_LP_ILK, 0);

        /* According to the spec, bit 13 (RCZUNIT) must be set on IVB.
         * This implements the WaDisableRCZUnitClockGating workaround.
         */
        I915_WRITE(GEN6_UCGCTL2, GEN6_RCZUNIT_CLOCK_GATE_DISABLE);

        I915_WRITE(ILK_DSPCLK_GATE, IVB_VRHUNIT_CLK_GATE);

        I915_WRITE(IVB_CHICKEN3,
                   CHICKEN3_DGMG_REQ_OUT_FIX_DISABLE |
                   CHICKEN3_DGMG_DONE_FIX_DISABLE);

        /* Apply the WaDisableRHWOOptimizationForRenderHang workaround. */
        I915_WRITE(GEN7_COMMON_SLICE_CHICKEN1,
                   GEN7_CSC1_RHWO_OPT_DISABLE_IN_RCC);

        /* WaApplyL3ControlAndL3ChickenMode requires those two on Ivy Bridge */
        I915_WRITE(GEN7_L3CNTLREG1, GEN7_WA_FOR_GEN7_L3_CONTROL);
        I915_WRITE(GEN7_L3_CHICKEN_MODE_REGISTER, GEN7_WA_L3_CHICKEN_MODE);

        /* This is required by WaCatErrorRejectionIssue */
        I915_WRITE(GEN7_SQ_CHICKEN_MBCUNIT_CONFIG,
                   I915_READ(GEN7_SQ_CHICKEN_MBCUNIT_CONFIG) |
                   GEN7_SQ_CHICKEN_MBCUNIT_SQINTMOB);

        for_each_pipe(pipe) {
                I915_WRITE(DSPCNTR(pipe),
                           I915_READ(DSPCNTR(pipe)) |
                           DISPPLANE_TRICKLE_FEED_DISABLE);
                intel_flush_display_plane(dev_priv, pipe);
        }

        I915_WRITE(CACHE_MODE_1,
                   _MASKED_BIT_ENABLE(PIXEL_SUBSPAN_COLLECT_OPT_DISABLE));
}

static void g4x_init_clock_gating(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        uint32_t dspclk_gate;

        I915_WRITE(RENCLK_GATE_D1, 0);
        I915_WRITE(RENCLK_GATE_D2, VF_UNIT_CLOCK_GATE_DISABLE |
                   GS_UNIT_CLOCK_GATE_DISABLE |
                   CL_UNIT_CLOCK_GATE_DISABLE);
        I915_WRITE(RAMCLK_GATE_D, 0);
        dspclk_gate = VRHUNIT_CLOCK_GATE_DISABLE |
                OVRUNIT_CLOCK_GATE_DISABLE |
                OVCUNIT_CLOCK_GATE_DISABLE;
        if (IS_GM45(dev))
                dspclk_gate |= DSSUNIT_CLOCK_GATE_DISABLE;
        I915_WRITE(DSPCLK_GATE_D, dspclk_gate);
}

static void crestline_init_clock_gating(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        I915_WRITE(RENCLK_GATE_D1, I965_RCC_CLOCK_GATE_DISABLE);
        I915_WRITE(RENCLK_GATE_D2, 0);
        I915_WRITE(DSPCLK_GATE_D, 0);
        I915_WRITE(RAMCLK_GATE_D, 0);
        I915_WRITE16(DEUC, 0);
}

static void broadwater_init_clock_gating(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        I915_WRITE(RENCLK_GATE_D1, I965_RCZ_CLOCK_GATE_DISABLE |
                   I965_RCC_CLOCK_GATE_DISABLE |
                   I965_RCPB_CLOCK_GATE_DISABLE |
                   I965_ISC_CLOCK_GATE_DISABLE |
                   I965_FBC_CLOCK_GATE_DISABLE);
        I915_WRITE(RENCLK_GATE_D2, 0);
}

static void gen3_init_clock_gating(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 dstate = I915_READ(D_STATE);

        dstate |= DSTATE_PLL_D3_OFF | DSTATE_GFX_CLOCK_GATING |
                DSTATE_DOT_CLOCK_GATING;
        I915_WRITE(D_STATE, dstate);

        if (IS_PINEVIEW(dev))
                I915_WRITE(ECOSKPD, _MASKED_BIT_ENABLE(ECO_GATING_CX_ONLY));
}

static void i85x_init_clock_gating(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        I915_WRITE(RENCLK_GATE_D1, SV_CLOCK_GATE_DISABLE);
}

static void i830_init_clock_gating(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        I915_WRITE(DSPCLK_GATE_D, OVRUNIT_CLOCK_GATE_DISABLE);
}

static void ibx_init_clock_gating(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        /*
         * On Ibex Peak and Cougar Point, we need to disable clock
         * gating for the panel power sequencer or it will fail to
         * start up when no ports are active.
         */
        I915_WRITE(SOUTH_DSPCLK_GATE_D, PCH_DPLSUNIT_CLOCK_GATE_DISABLE);
}

static void cpt_init_clock_gating(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        int pipe;

        /*
         * On Ibex Peak and Cougar Point, we need to disable clock
         * gating for the panel power sequencer or it will fail to
         * start up when no ports are active.
         */
        I915_WRITE(SOUTH_DSPCLK_GATE_D, PCH_DPLSUNIT_CLOCK_GATE_DISABLE);
        I915_WRITE(SOUTH_CHICKEN2, I915_READ(SOUTH_CHICKEN2) |
                   DPLS_EDP_PPS_FIX_DIS);
        /* Without this, mode sets may fail silently on FDI */
        for_each_pipe(pipe)
                I915_WRITE(TRANS_CHICKEN2(pipe), TRANS_AUTOTRAIN_GEN_STALL_DIS);
}

void intel_init_clock_gating(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        dev_priv->display.init_clock_gating(dev);

        if (dev_priv->display.init_pch_clock_gating)
                dev_priv->display.init_pch_clock_gating(dev);
}

static void gen6_sanitize_pm(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 limits, delay, old;

        gen6_gt_force_wake_get(dev_priv);

        old = limits = I915_READ(GEN6_RP_INTERRUPT_LIMITS);
        /* Make sure we continue to get interrupts
         * until we hit the minimum or maximum frequencies.
         */
        limits &= ~(0x3f << 16 | 0x3f << 24);
        delay = dev_priv->cur_delay;
        if (delay < dev_priv->max_delay)
                limits |= (dev_priv->max_delay & 0x3f) << 24;
        if (delay > dev_priv->min_delay)
                limits |= (dev_priv->min_delay & 0x3f) << 16;

        if (old != limits) {
                DRM_ERROR("Power management discrepancy: GEN6_RP_INTERRUPT_LIMITS expected %08x, was %08x\n",
                          limits, old);
                I915_WRITE(GEN6_RP_INTERRUPT_LIMITS, limits);
        }

        gen6_gt_force_wake_put(dev_priv);
}

void intel_sanitize_pm(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        if (dev_priv->display.sanitize_pm)
                dev_priv->display.sanitize_pm(dev);
}

/* Starting with Haswell, we have different power wells for
 * different parts of the GPU. This attempts to enable them all.
 */
static void intel_init_power_wells(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        unsigned long power_wells[] = {
                HSW_PWR_WELL_CTL1,
                HSW_PWR_WELL_CTL2,
                HSW_PWR_WELL_CTL4
        };
        int i;

        if (!IS_HASWELL(dev))
                return;

        DRM_LOCK(dev);

        for (i = 0; i < DRM_ARRAY_SIZE(power_wells); i++) {
                int well = I915_READ(power_wells[i]);

                if ((well & HSW_PWR_WELL_STATE) == 0) {
                        I915_WRITE(power_wells[i], well & HSW_PWR_WELL_ENABLE);
                        if (wait_for(I915_READ(power_wells[i] & HSW_PWR_WELL_STATE), 20))
                                DRM_ERROR("Error enabling power well %lx\n", power_wells[i]);
                }
        }

printf("XXXKIB HACK: HSW RC OFF\n");
        I915_WRITE(GEN6_RC_STATE, 0);
        I915_WRITE(GEN6_RC_CONTROL, 0);
        DRM_UNLOCK(dev);
}

/* Set up chip specific power management-related functions */
void intel_init_pm(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        if (I915_HAS_FBC(dev)) {
                if (HAS_PCH_SPLIT(dev)) {
                        dev_priv->display.fbc_enabled = ironlake_fbc_enabled;
                        dev_priv->display.enable_fbc = ironlake_enable_fbc;
                        dev_priv->display.disable_fbc = ironlake_disable_fbc;
                } else if (IS_GM45(dev)) {
                        dev_priv->display.fbc_enabled = g4x_fbc_enabled;
                        dev_priv->display.enable_fbc = g4x_enable_fbc;
                        dev_priv->display.disable_fbc = g4x_disable_fbc;
                } else if (IS_CRESTLINE(dev)) {
                        dev_priv->display.fbc_enabled = i8xx_fbc_enabled;
                        dev_priv->display.enable_fbc = i8xx_enable_fbc;
                        dev_priv->display.disable_fbc = i8xx_disable_fbc;
                }
                /* 855GM needs testing */
        }

        /* For cxsr */
        if (IS_PINEVIEW(dev))
                i915_pineview_get_mem_freq(dev);
        else if (IS_GEN5(dev))
                i915_ironlake_get_mem_freq(dev);

        /* For FIFO watermark updates */
        if (HAS_PCH_SPLIT(dev)) {
                dev_priv->display.force_wake_get = __gen6_gt_force_wake_get;
                dev_priv->display.force_wake_put = __gen6_gt_force_wake_put;

                /* IVB configs may use multi-threaded forcewake */
                if (IS_IVYBRIDGE(dev) || IS_HASWELL(dev)) {
                        u32     ecobus;

                        /* A small trick here - if the bios hasn't configured MT forcewake,
                         * and if the device is in RC6, then force_wake_mt_get will not wake
                         * the device and the ECOBUS read will return zero. Which will be
                         * (correctly) interpreted by the test below as MT forcewake being
                         * disabled.
                         */
                        DRM_LOCK(dev);
                        __gen6_gt_force_wake_mt_get(dev_priv);
                        ecobus = I915_READ_NOTRACE(ECOBUS);
                        __gen6_gt_force_wake_mt_put(dev_priv);
                        DRM_UNLOCK(dev);

                        if (ecobus & FORCEWAKE_MT_ENABLE) {
                                DRM_DEBUG_KMS("Using MT version of forcewake\n");
                                dev_priv->display.force_wake_get =
                                        __gen6_gt_force_wake_mt_get;
                                dev_priv->display.force_wake_put =
                                        __gen6_gt_force_wake_mt_put;
                        }
                }

                if (HAS_PCH_IBX(dev))
                        dev_priv->display.init_pch_clock_gating = ibx_init_clock_gating;
                else if (HAS_PCH_CPT(dev))
                        dev_priv->display.init_pch_clock_gating = cpt_init_clock_gating;

                if (IS_GEN5(dev)) {
                        if (I915_READ(MLTR_ILK) & ILK_SRLT_MASK)
                                dev_priv->display.update_wm = ironlake_update_wm;
                        else {
                                DRM_DEBUG_KMS("Failed to get proper latency. "
                                              "Disable CxSR\n");
                                dev_priv->display.update_wm = NULL;
                        }
                        dev_priv->display.init_clock_gating = ironlake_init_clock_gating;
                } else if (IS_GEN6(dev)) {
                        if (SNB_READ_WM0_LATENCY()) {
                                dev_priv->display.update_wm = sandybridge_update_wm;
                                dev_priv->display.update_sprite_wm = sandybridge_update_sprite_wm;
                        } else {
                                DRM_DEBUG_KMS("Failed to read display plane latency. "
                                              "Disable CxSR\n");
                                dev_priv->display.update_wm = NULL;
                        }
                        dev_priv->display.init_clock_gating = gen6_init_clock_gating;
                        dev_priv->display.sanitize_pm = gen6_sanitize_pm;
                } else if (IS_IVYBRIDGE(dev)) {
                        /* FIXME: detect B0+ stepping and use auto training */
                        if (SNB_READ_WM0_LATENCY()) {
                                dev_priv->display.update_wm = sandybridge_update_wm;
                                dev_priv->display.update_sprite_wm = sandybridge_update_sprite_wm;
                        } else {
                                DRM_DEBUG_KMS("Failed to read display plane latency. "
                                              "Disable CxSR\n");
                                dev_priv->display.update_wm = NULL;
                        }
                        dev_priv->display.init_clock_gating = ivybridge_init_clock_gating;
                        dev_priv->display.sanitize_pm = gen6_sanitize_pm;
                } else if (IS_HASWELL(dev)) {
                        if (SNB_READ_WM0_LATENCY()) {
                                dev_priv->display.update_wm = sandybridge_update_wm;
                                dev_priv->display.update_sprite_wm = sandybridge_update_sprite_wm;
                                dev_priv->display.update_linetime_wm = haswell_update_linetime_wm;
                        } else {
                                DRM_DEBUG_KMS("Failed to read display plane latency. "
                                              "Disable CxSR\n");
                                dev_priv->display.update_wm = NULL;
                        }
                        dev_priv->display.init_clock_gating = ivybridge_init_clock_gating;
                        dev_priv->display.sanitize_pm = gen6_sanitize_pm;
                } else
                        dev_priv->display.update_wm = NULL;
        } else if (IS_VALLEYVIEW(dev)) {
                dev_priv->display.update_wm = valleyview_update_wm;
                dev_priv->display.init_clock_gating =
                        valleyview_init_clock_gating;
                dev_priv->display.force_wake_get = vlv_force_wake_get;
                dev_priv->display.force_wake_put = vlv_force_wake_put;
        } else if (IS_PINEVIEW(dev)) {
                if (!intel_get_cxsr_latency(IS_PINEVIEW_G(dev),
                                            dev_priv->is_ddr3,
                                            dev_priv->fsb_freq,
                                            dev_priv->mem_freq)) {
                        DRM_INFO("failed to find known CxSR latency "
                                 "(found ddr%s fsb freq %d, mem freq %d), "
                                 "disabling CxSR\n",
                                 (dev_priv->is_ddr3 == 1) ? "3" : "2",
                                 dev_priv->fsb_freq, dev_priv->mem_freq);
                        /* Disable CxSR and never update its watermark again */
                        pineview_disable_cxsr(dev);
                        dev_priv->display.update_wm = NULL;
                } else
                        dev_priv->display.update_wm = pineview_update_wm;
                dev_priv->display.init_clock_gating = gen3_init_clock_gating;
        } else if (IS_G4X(dev)) {
                dev_priv->display.update_wm = g4x_update_wm;
                dev_priv->display.init_clock_gating = g4x_init_clock_gating;
        } else if (IS_GEN4(dev)) {
                dev_priv->display.update_wm = i965_update_wm;
                if (IS_CRESTLINE(dev))
                        dev_priv->display.init_clock_gating = crestline_init_clock_gating;
                else if (IS_BROADWATER(dev))
                        dev_priv->display.init_clock_gating = broadwater_init_clock_gating;
        } else if (IS_GEN3(dev)) {
                dev_priv->display.update_wm = i9xx_update_wm;
                dev_priv->display.get_fifo_size = i9xx_get_fifo_size;
                dev_priv->display.init_clock_gating = gen3_init_clock_gating;
        } else if (IS_I865G(dev)) {
                dev_priv->display.update_wm = i830_update_wm;
                dev_priv->display.init_clock_gating = i85x_init_clock_gating;
                dev_priv->display.get_fifo_size = i830_get_fifo_size;
        } else if (IS_I85X(dev)) {
                dev_priv->display.update_wm = i9xx_update_wm;
                dev_priv->display.get_fifo_size = i85x_get_fifo_size;
                dev_priv->display.init_clock_gating = i85x_init_clock_gating;
        } else {
                dev_priv->display.update_wm = i830_update_wm;
                dev_priv->display.init_clock_gating = i830_init_clock_gating;
                if (IS_845G(dev))
                        dev_priv->display.get_fifo_size = i845_get_fifo_size;
                else
                        dev_priv->display.get_fifo_size = i830_get_fifo_size;
        }

        /* We attempt to init the necessary power wells early in the initialization
         * time, so the subsystems that expect power to be enabled can work.
         */
        intel_init_power_wells(dev);
}

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