/*
 * Copyright © 2008-2010 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:
 *    Eric Anholt <eric@anholt.net>
 *    Zou Nan hai <nanhai.zou@intel.com>
 *    Xiang Hai hao<haihao.xiang@intel.com>
 *
 */

#include "drmP.h"
#include "drm.h"
#include "i915_drv.h"
#include "i915_drm.h"
#include "i915_trace.h"
#include "intel_drv.h"

/*
 * 965+ support PIPE_CONTROL commands, which provide finer grained control
 * over cache flushing.
 */
struct pipe_control {
        struct drm_i915_gem_object *obj;
        volatile u32 *cpu_page;
        u32 gtt_offset;
};

static inline int ring_space(struct intel_ring_buffer *ring)
{
        int space = (ring->head & HEAD_ADDR) - (ring->tail + 8);
        if (space < 0)
                space += ring->size;
        return space;
}

static u32 i915_gem_get_seqno(struct drm_device *dev)
{
        drm_i915_private_t *dev_priv = dev->dev_private;
        u32 seqno;

        seqno = dev_priv->next_seqno;

        /* reserve 0 for non-seqno */
        if (++dev_priv->next_seqno == 0)
                dev_priv->next_seqno = 1;

        return seqno;
}

static int
render_ring_flush(struct intel_ring_buffer *ring,
                  u32   invalidate_domains,
                  u32   flush_domains)
{
        struct drm_device *dev = ring->dev;
        u32 cmd;
        int ret;

        /*
         * read/write caches:
         *
         * I915_GEM_DOMAIN_RENDER is always invalidated, but is
         * only flushed if MI_NO_WRITE_FLUSH is unset.  On 965, it is
         * also flushed at 2d versus 3d pipeline switches.
         *
         * read-only caches:
         *
         * I915_GEM_DOMAIN_SAMPLER is flushed on pre-965 if
         * MI_READ_FLUSH is set, and is always flushed on 965.
         *
         * I915_GEM_DOMAIN_COMMAND may not exist?
         *
         * I915_GEM_DOMAIN_INSTRUCTION, which exists on 965, is
         * invalidated when MI_EXE_FLUSH is set.
         *
         * I915_GEM_DOMAIN_VERTEX, which exists on 965, is
         * invalidated with every MI_FLUSH.
         *
         * TLBs:
         *
         * On 965, TLBs associated with I915_GEM_DOMAIN_COMMAND
         * and I915_GEM_DOMAIN_CPU in are invalidated at PTE write and
         * I915_GEM_DOMAIN_RENDER and I915_GEM_DOMAIN_SAMPLER
         * are flushed at any MI_FLUSH.
         */

        cmd = MI_FLUSH | MI_NO_WRITE_FLUSH;
        if ((invalidate_domains|flush_domains) &
            I915_GEM_DOMAIN_RENDER)
                cmd &= ~MI_NO_WRITE_FLUSH;
        if (INTEL_INFO(dev)->gen < 4) {
                /*
                 * On the 965, the sampler cache always gets flushed
                 * and this bit is reserved.
                 */
                if (invalidate_domains & I915_GEM_DOMAIN_SAMPLER)
                        cmd |= MI_READ_FLUSH;
        }
        if (invalidate_domains & I915_GEM_DOMAIN_INSTRUCTION)
                cmd |= MI_EXE_FLUSH;

        if (invalidate_domains & I915_GEM_DOMAIN_COMMAND &&
            (IS_G4X(dev) || IS_GEN5(dev)))
                cmd |= MI_INVALIDATE_ISP;

        ret = intel_ring_begin(ring, 2);
        if (ret)
                return ret;

        intel_ring_emit(ring, cmd);
        intel_ring_emit(ring, MI_NOOP);
        intel_ring_advance(ring);

        return 0;
}

/**
 * Emits a PIPE_CONTROL with a non-zero post-sync operation, for
 * implementing two workarounds on gen6.  From section 1.4.7.1
 * "PIPE_CONTROL" of the Sandy Bridge PRM volume 2 part 1:
 *
 * [DevSNB-C+{W/A}] Before any depth stall flush (including those
 * produced by non-pipelined state commands), software needs to first
 * send a PIPE_CONTROL with no bits set except Post-Sync Operation !=
 * 0.
 *
 * [Dev-SNB{W/A}]: Before a PIPE_CONTROL with Write Cache Flush Enable
 * =1, a PIPE_CONTROL with any non-zero post-sync-op is required.
 *
 * And the workaround for these two requires this workaround first:
 *
 * [Dev-SNB{W/A}]: Pipe-control with CS-stall bit set must be sent
 * BEFORE the pipe-control with a post-sync op and no write-cache
 * flushes.
 *
 * And this last workaround is tricky because of the requirements on
 * that bit.  From section 1.4.7.2.3 "Stall" of the Sandy Bridge PRM
 * volume 2 part 1:
 *
 *     "1 of the following must also be set:
 *      - Render Target Cache Flush Enable ([12] of DW1)
 *      - Depth Cache Flush Enable ([0] of DW1)
 *      - Stall at Pixel Scoreboard ([1] of DW1)
 *      - Depth Stall ([13] of DW1)
 *      - Post-Sync Operation ([13] of DW1)
 *      - Notify Enable ([8] of DW1)"
 *
 * The cache flushes require the workaround flush that triggered this
 * one, so we can't use it.  Depth stall would trigger the same.
 * Post-sync nonzero is what triggered this second workaround, so we
 * can't use that one either.  Notify enable is IRQs, which aren't
 * really our business.  That leaves only stall at scoreboard.
 */
static int
intel_emit_post_sync_nonzero_flush(struct intel_ring_buffer *ring)
{
        struct pipe_control *pc = ring->private;
        u32 scratch_addr = pc->gtt_offset + 128;
        int ret;


        ret = intel_ring_begin(ring, 6);
        if (ret)
                return ret;

        intel_ring_emit(ring, GFX_OP_PIPE_CONTROL(5));
        intel_ring_emit(ring, PIPE_CONTROL_CS_STALL |
                        PIPE_CONTROL_STALL_AT_SCOREBOARD);
        intel_ring_emit(ring, scratch_addr | PIPE_CONTROL_GLOBAL_GTT); /* address */
        intel_ring_emit(ring, 0); /* low dword */
        intel_ring_emit(ring, 0); /* high dword */
        intel_ring_emit(ring, MI_NOOP);
        intel_ring_advance(ring);

        ret = intel_ring_begin(ring, 6);
        if (ret)
                return ret;

        intel_ring_emit(ring, GFX_OP_PIPE_CONTROL(5));
        intel_ring_emit(ring, PIPE_CONTROL_QW_WRITE);
        intel_ring_emit(ring, scratch_addr | PIPE_CONTROL_GLOBAL_GTT); /* address */
        intel_ring_emit(ring, 0);
        intel_ring_emit(ring, 0);
        intel_ring_emit(ring, MI_NOOP);
        intel_ring_advance(ring);

        return 0;
}

static int
gen6_render_ring_flush(struct intel_ring_buffer *ring,
                         u32 invalidate_domains, u32 flush_domains)
{
        u32 flags = 0;
        struct pipe_control *pc = ring->private;
        u32 scratch_addr = pc->gtt_offset + 128;
        int ret;

        /* Force SNB workarounds for PIPE_CONTROL flushes */
        intel_emit_post_sync_nonzero_flush(ring);

        /* Just flush everything.  Experiments have shown that reducing the
         * number of bits based on the write domains has little performance
         * impact.
         */
        flags |= PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH;
        flags |= PIPE_CONTROL_INSTRUCTION_CACHE_INVALIDATE;
        flags |= PIPE_CONTROL_TEXTURE_CACHE_INVALIDATE;
        flags |= PIPE_CONTROL_DEPTH_CACHE_FLUSH;
        flags |= PIPE_CONTROL_VF_CACHE_INVALIDATE;
        flags |= PIPE_CONTROL_CONST_CACHE_INVALIDATE;
        flags |= PIPE_CONTROL_STATE_CACHE_INVALIDATE;

        ret = intel_ring_begin(ring, 6);
        if (ret)
                return ret;

        intel_ring_emit(ring, GFX_OP_PIPE_CONTROL(5));
        intel_ring_emit(ring, flags);
        intel_ring_emit(ring, scratch_addr | PIPE_CONTROL_GLOBAL_GTT);
        intel_ring_emit(ring, 0); /* lower dword */
        intel_ring_emit(ring, 0); /* uppwer dword */
        intel_ring_emit(ring, MI_NOOP);
        intel_ring_advance(ring);

        return 0;
}

static void ring_write_tail(struct intel_ring_buffer *ring,
                            u32 value)
{
        drm_i915_private_t *dev_priv = ring->dev->dev_private;
        I915_WRITE_TAIL(ring, value);
}

u32 intel_ring_get_active_head(struct intel_ring_buffer *ring)
{
        drm_i915_private_t *dev_priv = ring->dev->dev_private;
        u32 acthd_reg = INTEL_INFO(ring->dev)->gen >= 4 ?
                        RING_ACTHD(ring->mmio_base) : ACTHD;

        return I915_READ(acthd_reg);
}

static int init_ring_common(struct intel_ring_buffer *ring)
{
        drm_i915_private_t *dev_priv = ring->dev->dev_private;
        struct drm_i915_gem_object *obj = ring->obj;
        u32 head;

        /* Stop the ring if it's running. */
        I915_WRITE_CTL(ring, 0);
        I915_WRITE_HEAD(ring, 0);
        ring->write_tail(ring, 0);

        /* Initialize the ring. */
        I915_WRITE_START(ring, obj->gtt_offset);
        head = I915_READ_HEAD(ring) & HEAD_ADDR;

        /* G45 ring initialization fails to reset head to zero */
        if (head != 0) {
                DRM_DEBUG_KMS("%s head not reset to zero "
                              "ctl %08x head %08x tail %08x start %08x\n",
                              ring->name,
                              I915_READ_CTL(ring),
                              I915_READ_HEAD(ring),
                              I915_READ_TAIL(ring),
                              I915_READ_START(ring));

                I915_WRITE_HEAD(ring, 0);

                if (I915_READ_HEAD(ring) & HEAD_ADDR) {
                        DRM_ERROR("failed to set %s head to zero "
                                  "ctl %08x head %08x tail %08x start %08x\n",
                                  ring->name,
                                  I915_READ_CTL(ring),
                                  I915_READ_HEAD(ring),
                                  I915_READ_TAIL(ring),
                                  I915_READ_START(ring));
                }
        }

        I915_WRITE_CTL(ring,
                        ((ring->size - PAGE_SIZE) & RING_NR_PAGES)
                        | RING_REPORT_64K | RING_VALID);

        /* If the head is still not zero, the ring is dead */
        if ((I915_READ_CTL(ring) & RING_VALID) == 0 ||
            I915_READ_START(ring) != obj->gtt_offset ||
            (I915_READ_HEAD(ring) & HEAD_ADDR) != 0) {
                DRM_ERROR("%s initialization failed "
                                "ctl %08x head %08x tail %08x start %08x\n",
                                ring->name,
                                I915_READ_CTL(ring),
                                I915_READ_HEAD(ring),
                                I915_READ_TAIL(ring),
                                I915_READ_START(ring));
                return -EIO;
        }

        if (!drm_core_check_feature(ring->dev, DRIVER_MODESET))
                i915_kernel_lost_context(ring->dev);
        else {
                ring->head = I915_READ_HEAD(ring);
                ring->tail = I915_READ_TAIL(ring) & TAIL_ADDR;
                ring->space = ring_space(ring);
        }

        return 0;
}

static int
init_pipe_control(struct intel_ring_buffer *ring)
{
        struct pipe_control *pc;
        struct drm_i915_gem_object *obj;
        int ret;

        if (ring->private)
                return 0;

        pc = kmalloc(sizeof(*pc), GFP_KERNEL);
        if (!pc)
                return -ENOMEM;

        obj = i915_gem_alloc_object(ring->dev, 4096);
        if (obj == NULL) {
                DRM_ERROR("Failed to allocate seqno page\n");
                ret = -ENOMEM;
                goto err;
        }

        i915_gem_object_set_cache_level(obj, I915_CACHE_LLC);

        ret = i915_gem_object_pin(obj, 4096, true);
        if (ret)
                goto err_unref;

        pc->gtt_offset = obj->gtt_offset;
        pc->cpu_page =  kmap(obj->pages[0]);
        if (pc->cpu_page == NULL)
                goto err_unpin;

        pc->obj = obj;
        ring->private = pc;
        return 0;

err_unpin:
        i915_gem_object_unpin(obj);
err_unref:
        drm_gem_object_unreference(&obj->base);
err:
        kfree(pc);
        return ret;
}

static void
cleanup_pipe_control(struct intel_ring_buffer *ring)
{
        struct pipe_control *pc = ring->private;
        struct drm_i915_gem_object *obj;

        if (!ring->private)
                return;

        obj = pc->obj;
        kunmap(obj->pages[0]);
        i915_gem_object_unpin(obj);
        drm_gem_object_unreference(&obj->base);

        kfree(pc);
        ring->private = NULL;
}

static int init_render_ring(struct intel_ring_buffer *ring)
{
        struct drm_device *dev = ring->dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        int ret = init_ring_common(ring);

        if (INTEL_INFO(dev)->gen > 3) {
                int mode = VS_TIMER_DISPATCH << 16 | VS_TIMER_DISPATCH;
                if (IS_GEN6(dev) || IS_GEN7(dev))
                        mode |= MI_FLUSH_ENABLE << 16 | MI_FLUSH_ENABLE;
                I915_WRITE(MI_MODE, mode);
                if (IS_GEN7(dev))
                        I915_WRITE(GFX_MODE_GEN7,
                                   GFX_MODE_DISABLE(GFX_TLB_INVALIDATE_ALWAYS) |
                                   GFX_MODE_ENABLE(GFX_REPLAY_MODE));
        }

        if (INTEL_INFO(dev)->gen >= 5) {
                ret = init_pipe_control(ring);
                if (ret)
                        return ret;
        }

        return ret;
}

static void render_ring_cleanup(struct intel_ring_buffer *ring)
{
        if (!ring->private)
                return;

        cleanup_pipe_control(ring);
}

static void
update_mboxes(struct intel_ring_buffer *ring,
            u32 seqno,
            u32 mmio_offset)
{
        intel_ring_emit(ring, MI_SEMAPHORE_MBOX |
                              MI_SEMAPHORE_GLOBAL_GTT |
                              MI_SEMAPHORE_REGISTER |
                              MI_SEMAPHORE_UPDATE);
        intel_ring_emit(ring, seqno);
        intel_ring_emit(ring, mmio_offset);
}

/**
 * gen6_add_request - Update the semaphore mailbox registers
 * 
 * @ring - ring that is adding a request
 * @seqno - return seqno stuck into the ring
 *
 * Update the mailbox registers in the *other* rings with the current seqno.
 * This acts like a signal in the canonical semaphore.
 */
static int
gen6_add_request(struct intel_ring_buffer *ring,
                 u32 *seqno)
{
        u32 mbox1_reg;
        u32 mbox2_reg;
        int ret;

        ret = intel_ring_begin(ring, 10);
        if (ret)
                return ret;

        mbox1_reg = ring->signal_mbox[0];
        mbox2_reg = ring->signal_mbox[1];

        *seqno = i915_gem_get_seqno(ring->dev);

        update_mboxes(ring, *seqno, mbox1_reg);
        update_mboxes(ring, *seqno, mbox2_reg);
        intel_ring_emit(ring, MI_STORE_DWORD_INDEX);
        intel_ring_emit(ring, I915_GEM_HWS_INDEX << MI_STORE_DWORD_INDEX_SHIFT);
        intel_ring_emit(ring, *seqno);
        intel_ring_emit(ring, MI_USER_INTERRUPT);
        intel_ring_advance(ring);

        return 0;
}

/**
 * intel_ring_sync - sync the waiter to the signaller on seqno
 *
 * @waiter - ring that is waiting
 * @signaller - ring which has, or will signal
 * @seqno - seqno which the waiter will block on
 */
static int
intel_ring_sync(struct intel_ring_buffer *waiter,
                struct intel_ring_buffer *signaller,
                int ring,
                u32 seqno)
{
        int ret;
        u32 dw1 = MI_SEMAPHORE_MBOX |
                  MI_SEMAPHORE_COMPARE |
                  MI_SEMAPHORE_REGISTER;

        ret = intel_ring_begin(waiter, 4);
        if (ret)
                return ret;

        intel_ring_emit(waiter, dw1 | signaller->semaphore_register[ring]);
        intel_ring_emit(waiter, seqno);
        intel_ring_emit(waiter, 0);
        intel_ring_emit(waiter, MI_NOOP);
        intel_ring_advance(waiter);

        return 0;
}

/* VCS->RCS (RVSYNC) or BCS->RCS (RBSYNC) */
int
render_ring_sync_to(struct intel_ring_buffer *waiter,
                    struct intel_ring_buffer *signaller,
                    u32 seqno)
{
        WARN_ON(signaller->semaphore_register[RCS] == MI_SEMAPHORE_SYNC_INVALID);
        return intel_ring_sync(waiter,
                               signaller,
                               RCS,
                               seqno);
}

/* RCS->VCS (VRSYNC) or BCS->VCS (VBSYNC) */
int
gen6_bsd_ring_sync_to(struct intel_ring_buffer *waiter,
                      struct intel_ring_buffer *signaller,
                      u32 seqno)
{
        WARN_ON(signaller->semaphore_register[VCS] == MI_SEMAPHORE_SYNC_INVALID);
        return intel_ring_sync(waiter,
                               signaller,
                               VCS,
                               seqno);
}

/* RCS->BCS (BRSYNC) or VCS->BCS (BVSYNC) */
int
gen6_blt_ring_sync_to(struct intel_ring_buffer *waiter,
                      struct intel_ring_buffer *signaller,
                      u32 seqno)
{
        WARN_ON(signaller->semaphore_register[BCS] == MI_SEMAPHORE_SYNC_INVALID);
        return intel_ring_sync(waiter,
                               signaller,
                               BCS,
                               seqno);
}



#define PIPE_CONTROL_FLUSH(ring__, addr__)                                      \
do {                                                                    \
        intel_ring_emit(ring__, GFX_OP_PIPE_CONTROL(4) | PIPE_CONTROL_QW_WRITE |                \
                 PIPE_CONTROL_DEPTH_STALL);                             \
        intel_ring_emit(ring__, (addr__) | PIPE_CONTROL_GLOBAL_GTT);                    \
        intel_ring_emit(ring__, 0);                                                     \
        intel_ring_emit(ring__, 0);                                                     \
} while (0)

static int
pc_render_add_request(struct intel_ring_buffer *ring,
                      u32 *result)
{
        struct drm_device *dev = ring->dev;
        u32 seqno = i915_gem_get_seqno(dev);
        struct pipe_control *pc = ring->private;
        u32 scratch_addr = pc->gtt_offset + 128;
        int ret;

        /* For Ironlake, MI_USER_INTERRUPT was deprecated and apparently
         * incoherent with writes to memory, i.e. completely fubar,
         * so we need to use PIPE_NOTIFY instead.
         *
         * However, we also need to workaround the qword write
         * incoherence by flushing the 6 PIPE_NOTIFY buffers out to
         * memory before requesting an interrupt.
         */
        ret = intel_ring_begin(ring, 32);
        if (ret)
                return ret;

        intel_ring_emit(ring, GFX_OP_PIPE_CONTROL(4) | PIPE_CONTROL_QW_WRITE |
                        PIPE_CONTROL_WRITE_FLUSH |
                        PIPE_CONTROL_TEXTURE_CACHE_INVALIDATE);
        intel_ring_emit(ring, pc->gtt_offset | PIPE_CONTROL_GLOBAL_GTT);
        intel_ring_emit(ring, seqno);
        intel_ring_emit(ring, 0);
        PIPE_CONTROL_FLUSH(ring, scratch_addr);
        scratch_addr += 128; /* write to separate cachelines */
        PIPE_CONTROL_FLUSH(ring, scratch_addr);
        scratch_addr += 128;
        PIPE_CONTROL_FLUSH(ring, scratch_addr);
        scratch_addr += 128;
        PIPE_CONTROL_FLUSH(ring, scratch_addr);
        scratch_addr += 128;
        PIPE_CONTROL_FLUSH(ring, scratch_addr);
        scratch_addr += 128;
        PIPE_CONTROL_FLUSH(ring, scratch_addr);
        intel_ring_emit(ring, GFX_OP_PIPE_CONTROL(4) | PIPE_CONTROL_QW_WRITE |
                        PIPE_CONTROL_WRITE_FLUSH |
                        PIPE_CONTROL_TEXTURE_CACHE_INVALIDATE |
                        PIPE_CONTROL_NOTIFY);
        intel_ring_emit(ring, pc->gtt_offset | PIPE_CONTROL_GLOBAL_GTT);
        intel_ring_emit(ring, seqno);
        intel_ring_emit(ring, 0);
        intel_ring_advance(ring);

        *result = seqno;
        return 0;
}

static int
render_ring_add_request(struct intel_ring_buffer *ring,
                        u32 *result)
{
        struct drm_device *dev = ring->dev;
        u32 seqno = i915_gem_get_seqno(dev);
        int ret;

        ret = intel_ring_begin(ring, 4);
        if (ret)
                return ret;

        intel_ring_emit(ring, MI_STORE_DWORD_INDEX);
        intel_ring_emit(ring, I915_GEM_HWS_INDEX << MI_STORE_DWORD_INDEX_SHIFT);
        intel_ring_emit(ring, seqno);
        intel_ring_emit(ring, MI_USER_INTERRUPT);
        intel_ring_advance(ring);

        *result = seqno;
        return 0;
}

static u32
ring_get_seqno(struct intel_ring_buffer *ring)
{
        return intel_read_status_page(ring, I915_GEM_HWS_INDEX);
}

static u32
pc_render_get_seqno(struct intel_ring_buffer *ring)
{
        struct pipe_control *pc = ring->private;
        return pc->cpu_page[0];
}

static void
ironlake_enable_irq(drm_i915_private_t *dev_priv, u32 mask)
{
        dev_priv->gt_irq_mask &= ~mask;
        I915_WRITE(GTIMR, dev_priv->gt_irq_mask);
        POSTING_READ(GTIMR);
}

static void
ironlake_disable_irq(drm_i915_private_t *dev_priv, u32 mask)
{
        dev_priv->gt_irq_mask |= mask;
        I915_WRITE(GTIMR, dev_priv->gt_irq_mask);
        POSTING_READ(GTIMR);
}

static void
i915_enable_irq(drm_i915_private_t *dev_priv, u32 mask)
{
        dev_priv->irq_mask &= ~mask;
        I915_WRITE(IMR, dev_priv->irq_mask);
        POSTING_READ(IMR);
}

static void
i915_disable_irq(drm_i915_private_t *dev_priv, u32 mask)
{
        dev_priv->irq_mask |= mask;
        I915_WRITE(IMR, dev_priv->irq_mask);
        POSTING_READ(IMR);
}

static bool
render_ring_get_irq(struct intel_ring_buffer *ring)
{
        struct drm_device *dev = ring->dev;
        drm_i915_private_t *dev_priv = dev->dev_private;

        if (!dev->irq_enabled)
                return false;

        spin_lock(&ring->irq_lock);
        if (ring->irq_refcount++ == 0) {
                if (HAS_PCH_SPLIT(dev))
                        ironlake_enable_irq(dev_priv,
                                            GT_PIPE_NOTIFY | GT_USER_INTERRUPT);
                else
                        i915_enable_irq(dev_priv, I915_USER_INTERRUPT);
        }
        spin_unlock(&ring->irq_lock);

        return true;
}

static void
render_ring_put_irq(struct intel_ring_buffer *ring)
{
        struct drm_device *dev = ring->dev;
        drm_i915_private_t *dev_priv = dev->dev_private;

        spin_lock(&ring->irq_lock);
        if (--ring->irq_refcount == 0) {
                if (HAS_PCH_SPLIT(dev))
                        ironlake_disable_irq(dev_priv,
                                             GT_USER_INTERRUPT |
                                             GT_PIPE_NOTIFY);
                else
                        i915_disable_irq(dev_priv, I915_USER_INTERRUPT);
        }
        spin_unlock(&ring->irq_lock);
}

void intel_ring_setup_status_page(struct intel_ring_buffer *ring)
{
        struct drm_device *dev = ring->dev;
        drm_i915_private_t *dev_priv = ring->dev->dev_private;
        u32 mmio = 0;

        /* The ring status page addresses are no longer next to the rest of
         * the ring registers as of gen7.
         */
        if (IS_GEN7(dev)) {
                switch (ring->id) {
                case RING_RENDER:
                        mmio = RENDER_HWS_PGA_GEN7;
                        break;
                case RING_BLT:
                        mmio = BLT_HWS_PGA_GEN7;
                        break;
                case RING_BSD:
                        mmio = BSD_HWS_PGA_GEN7;
                        break;
                }
        } else if (IS_GEN6(ring->dev)) {
                mmio = RING_HWS_PGA_GEN6(ring->mmio_base);
        } else {
                mmio = RING_HWS_PGA(ring->mmio_base);
        }

        I915_WRITE(mmio, (u32)ring->status_page.gfx_addr);
        POSTING_READ(mmio);
}

static int
bsd_ring_flush(struct intel_ring_buffer *ring,
               u32     invalidate_domains,
               u32     flush_domains)
{
        int ret;

        ret = intel_ring_begin(ring, 2);
        if (ret)
                return ret;

        intel_ring_emit(ring, MI_FLUSH);
        intel_ring_emit(ring, MI_NOOP);
        intel_ring_advance(ring);
        return 0;
}

static int
ring_add_request(struct intel_ring_buffer *ring,
                 u32 *result)
{
        u32 seqno;
        int ret;

        ret = intel_ring_begin(ring, 4);
        if (ret)
                return ret;

        seqno = i915_gem_get_seqno(ring->dev);

        intel_ring_emit(ring, MI_STORE_DWORD_INDEX);
        intel_ring_emit(ring, I915_GEM_HWS_INDEX << MI_STORE_DWORD_INDEX_SHIFT);
        intel_ring_emit(ring, seqno);
        intel_ring_emit(ring, MI_USER_INTERRUPT);
        intel_ring_advance(ring);

        *result = seqno;
        return 0;
}

static bool
gen6_ring_get_irq(struct intel_ring_buffer *ring, u32 gflag, u32 rflag)
{
        struct drm_device *dev = ring->dev;
        drm_i915_private_t *dev_priv = dev->dev_private;

        if (!dev->irq_enabled)
               return false;

        spin_lock(&ring->irq_lock);
        if (ring->irq_refcount++ == 0) {
                ring->irq_mask &= ~rflag;
                I915_WRITE_IMR(ring, ring->irq_mask);
                ironlake_enable_irq(dev_priv, gflag);
        }
        spin_unlock(&ring->irq_lock);

        return true;
}

static void
gen6_ring_put_irq(struct intel_ring_buffer *ring, u32 gflag, u32 rflag)
{
        struct drm_device *dev = ring->dev;
        drm_i915_private_t *dev_priv = dev->dev_private;

        spin_lock(&ring->irq_lock);
        if (--ring->irq_refcount == 0) {
                ring->irq_mask |= rflag;
                I915_WRITE_IMR(ring, ring->irq_mask);
                ironlake_disable_irq(dev_priv, gflag);
        }
        spin_unlock(&ring->irq_lock);
}

static bool
bsd_ring_get_irq(struct intel_ring_buffer *ring)
{
        struct drm_device *dev = ring->dev;
        drm_i915_private_t *dev_priv = dev->dev_private;

        if (!dev->irq_enabled)
                return false;

        spin_lock(&ring->irq_lock);
        if (ring->irq_refcount++ == 0) {
                if (IS_G4X(dev))
                        i915_enable_irq(dev_priv, I915_BSD_USER_INTERRUPT);
                else
                        ironlake_enable_irq(dev_priv, GT_BSD_USER_INTERRUPT);
        }
        spin_unlock(&ring->irq_lock);

        return true;
}
static void
bsd_ring_put_irq(struct intel_ring_buffer *ring)
{
        struct drm_device *dev = ring->dev;
        drm_i915_private_t *dev_priv = dev->dev_private;

        spin_lock(&ring->irq_lock);
        if (--ring->irq_refcount == 0) {
                if (IS_G4X(dev))
                        i915_disable_irq(dev_priv, I915_BSD_USER_INTERRUPT);
                else
                        ironlake_disable_irq(dev_priv, GT_BSD_USER_INTERRUPT);
        }
        spin_unlock(&ring->irq_lock);
}

static int
ring_dispatch_execbuffer(struct intel_ring_buffer *ring, u32 offset, u32 length)
{
        int ret;

        ret = intel_ring_begin(ring, 2);
        if (ret)
                return ret;

        intel_ring_emit(ring,
                        MI_BATCH_BUFFER_START | (2 << 6) |
                        MI_BATCH_NON_SECURE_I965);
        intel_ring_emit(ring, offset);
        intel_ring_advance(ring);

        return 0;
}

static int
render_ring_dispatch_execbuffer(struct intel_ring_buffer *ring,
                                u32 offset, u32 len)
{
        struct drm_device *dev = ring->dev;
        int ret;

        if (IS_I830(dev) || IS_845G(dev)) {
                ret = intel_ring_begin(ring, 4);
                if (ret)
                        return ret;

                intel_ring_emit(ring, MI_BATCH_BUFFER);
                intel_ring_emit(ring, offset | MI_BATCH_NON_SECURE);
                intel_ring_emit(ring, offset + len - 8);
                intel_ring_emit(ring, 0);
        } else {
                ret = intel_ring_begin(ring, 2);
                if (ret)
                        return ret;

                if (INTEL_INFO(dev)->gen >= 4) {
                        intel_ring_emit(ring,
                                        MI_BATCH_BUFFER_START | (2 << 6) |
                                        MI_BATCH_NON_SECURE_I965);
                        intel_ring_emit(ring, offset);
                } else {
                        intel_ring_emit(ring,
                                        MI_BATCH_BUFFER_START | (2 << 6));
                        intel_ring_emit(ring, offset | MI_BATCH_NON_SECURE);
                }
        }
        intel_ring_advance(ring);

        return 0;
}

static void cleanup_status_page(struct intel_ring_buffer *ring)
{
        drm_i915_private_t *dev_priv = ring->dev->dev_private;
        struct drm_i915_gem_object *obj;

        obj = ring->status_page.obj;
        if (obj == NULL)
                return;

        kunmap(obj->pages[0]);
        i915_gem_object_unpin(obj);
        drm_gem_object_unreference(&obj->base);
        ring->status_page.obj = NULL;

        memset(&dev_priv->hws_map, 0, sizeof(dev_priv->hws_map));
}

static int init_status_page(struct intel_ring_buffer *ring)
{
        struct drm_device *dev = ring->dev;
        drm_i915_private_t *dev_priv = dev->dev_private;
        struct drm_i915_gem_object *obj;
        int ret;

        obj = i915_gem_alloc_object(dev, 4096);
        if (obj == NULL) {
                DRM_ERROR("Failed to allocate status page\n");
                ret = -ENOMEM;
                goto err;
        }

        i915_gem_object_set_cache_level(obj, I915_CACHE_LLC);

        ret = i915_gem_object_pin(obj, 4096, true);
        if (ret != 0) {
                goto err_unref;
        }

        ring->status_page.gfx_addr = obj->gtt_offset;
        ring->status_page.page_addr = kmap(obj->pages[0]);
        if (ring->status_page.page_addr == NULL) {
                memset(&dev_priv->hws_map, 0, sizeof(dev_priv->hws_map));
                goto err_unpin;
        }
        ring->status_page.obj = obj;
        memset(ring->status_page.page_addr, 0, PAGE_SIZE);

        intel_ring_setup_status_page(ring);
        DRM_DEBUG_DRIVER("%s hws offset: 0x%08x\n",
                        ring->name, ring->status_page.gfx_addr);

        return 0;

err_unpin:
        i915_gem_object_unpin(obj);
err_unref:
        drm_gem_object_unreference(&obj->base);
err:
        return ret;
}

int intel_init_ring_buffer(struct drm_device *dev,
                           struct intel_ring_buffer *ring)
{
        struct drm_i915_gem_object *obj;
        int ret;

        ring->dev = dev;
        INIT_LIST_HEAD(&ring->active_list);
        INIT_LIST_HEAD(&ring->request_list);
        INIT_LIST_HEAD(&ring->gpu_write_list);

        init_waitqueue_head(&ring->irq_queue);
        spin_lock_init(&ring->irq_lock);
        ring->irq_mask = ~0;

        if (I915_NEED_GFX_HWS(dev)) {
                ret = init_status_page(ring);
                if (ret)
                        return ret;
        }

        obj = i915_gem_alloc_object(dev, ring->size);
        if (obj == NULL) {
                DRM_ERROR("Failed to allocate ringbuffer\n");
                ret = -ENOMEM;

                goto err_hws;
        }

        ring->obj = obj;

        ret = i915_gem_object_pin(obj, PAGE_SIZE, true);
        if (ret)
                goto err_unref;

        ring->map.size = ring->size;
        ring->map.offset = dev->agp->base + obj->gtt_offset;
        ring->map.type = 0;
        ring->map.flags = 0;
        ring->map.mtrr = 0;

        drm_core_ioremap_wc(&ring->map, dev);
        if (ring->map.handle == NULL) {
                DRM_ERROR("Failed to map ringbuffer.\n");
                ret = -EINVAL;
                goto err_unpin;
        }

        ring->virtual_start = ring->map.handle;
        ret = ring->init(ring);
        if (ret)
                goto err_unmap;

        /* Workaround an erratum on the i830 which causes a hang if
         * the TAIL pointer points to within the last 2 cachelines
         * of the buffer.
         */
        ring->effective_size = ring->size;
        if (IS_I830(ring->dev))
                ring->effective_size -= 128;

        return 0;

err_unmap:
        drm_core_ioremapfree(&ring->map, dev);
err_unpin:
        i915_gem_object_unpin(obj);
err_unref:
        drm_gem_object_unreference(&obj->base);
        ring->obj = NULL;
err_hws:
        cleanup_status_page(ring);
        return ret;
}

void intel_cleanup_ring_buffer(struct intel_ring_buffer *ring)
{
        struct drm_i915_private *dev_priv;
        int ret;

        if (ring->obj == NULL)
                return;

        /* Disable the ring buffer. The ring must be idle at this point */
        dev_priv = ring->dev->dev_private;
        ret = intel_wait_ring_idle(ring);
        if (ret)
                DRM_ERROR("failed to quiesce %s whilst cleaning up: %d\n",
                          ring->name, ret);

        I915_WRITE_CTL(ring, 0);

        drm_core_ioremapfree(&ring->map, ring->dev);

        i915_gem_object_unpin(ring->obj);
        drm_gem_object_unreference(&ring->obj->base);
        ring->obj = NULL;

        if (ring->cleanup)
                ring->cleanup(ring);

        cleanup_status_page(ring);
}

static int intel_wrap_ring_buffer(struct intel_ring_buffer *ring)
{
        unsigned int *virt;
        int rem = ring->size - ring->tail;

        if (ring->space < rem) {
                int ret = intel_wait_ring_buffer(ring, rem);
                if (ret)
                        return ret;
        }

        virt = (unsigned int *)(ring->virtual_start + ring->tail);
        rem /= 8;
        while (rem--) {
                *virt++ = MI_NOOP;
                *virt++ = MI_NOOP;
        }

        ring->tail = 0;
        ring->space = ring_space(ring);

        return 0;
}

int intel_wait_ring_buffer(struct intel_ring_buffer *ring, int n)
{
        struct drm_device *dev = ring->dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        unsigned long end;
        u32 head;

        /* If the reported head position has wrapped or hasn't advanced,
         * fallback to the slow and accurate path.
         */
        head = intel_read_status_page(ring, 4);
        if (head > ring->head) {
                ring->head = head;
                ring->space = ring_space(ring);
                if (ring->space >= n)
                        return 0;
        }

        trace_i915_ring_wait_begin(ring);
        end = jiffies + 3 * HZ;
        do {
                ring->head = I915_READ_HEAD(ring);
                ring->space = ring_space(ring);
                if (ring->space >= n) {
                        trace_i915_ring_wait_end(ring);
                        return 0;
                }

                if (dev->primary->master) {
                        struct drm_i915_master_private *master_priv = dev->primary->master->driver_priv;
                        if (master_priv->sarea_priv)
                                master_priv->sarea_priv->perf_boxes |= I915_BOX_WAIT;
                }

                msleep(1);
                if (atomic_read(&dev_priv->mm.wedged))
                        return -EAGAIN;
        } while (!time_after(jiffies, end));
        trace_i915_ring_wait_end(ring);
        return -EBUSY;
}

int intel_ring_begin(struct intel_ring_buffer *ring,
                     int num_dwords)
{
        struct drm_i915_private *dev_priv = ring->dev->dev_private;
        int n = 4*num_dwords;
        int ret;

        if (unlikely(atomic_read(&dev_priv->mm.wedged)))
                return -EIO;

        if (unlikely(ring->tail + n > ring->effective_size)) {
                ret = intel_wrap_ring_buffer(ring);
                if (unlikely(ret))
                        return ret;
        }

        if (unlikely(ring->space < n)) {
                ret = intel_wait_ring_buffer(ring, n);
                if (unlikely(ret))
                        return ret;
        }

        ring->space -= n;
        return 0;
}

void intel_ring_advance(struct intel_ring_buffer *ring)
{
        ring->tail &= ring->size - 1;
        ring->write_tail(ring, ring->tail);
}

static const struct intel_ring_buffer render_ring = {
        .name                   = "render ring",
        .id                     = RING_RENDER,
        .mmio_base              = RENDER_RING_BASE,
        .size                   = 32 * PAGE_SIZE,
        .init                   = init_render_ring,
        .write_tail             = ring_write_tail,
        .flush                  = render_ring_flush,
        .add_request            = render_ring_add_request,
        .get_seqno              = ring_get_seqno,
        .irq_get                = render_ring_get_irq,
        .irq_put                = render_ring_put_irq,
        .dispatch_execbuffer    = render_ring_dispatch_execbuffer,
        .cleanup                = render_ring_cleanup,
        .sync_to                = render_ring_sync_to,
        .semaphore_register     = {MI_SEMAPHORE_SYNC_INVALID,
                                   MI_SEMAPHORE_SYNC_RV,
                                   MI_SEMAPHORE_SYNC_RB},
        .signal_mbox            = {GEN6_VRSYNC, GEN6_BRSYNC},
};

/* ring buffer for bit-stream decoder */

static const struct intel_ring_buffer bsd_ring = {
        .name                   = "bsd ring",
        .id                     = RING_BSD,
        .mmio_base              = BSD_RING_BASE,
        .size                   = 32 * PAGE_SIZE,
        .init                   = init_ring_common,
        .write_tail             = ring_write_tail,
        .flush                  = bsd_ring_flush,
        .add_request            = ring_add_request,
        .get_seqno              = ring_get_seqno,
        .irq_get                = bsd_ring_get_irq,
        .irq_put                = bsd_ring_put_irq,
        .dispatch_execbuffer    = ring_dispatch_execbuffer,
};


static void gen6_bsd_ring_write_tail(struct intel_ring_buffer *ring,
                                     u32 value)
{
        drm_i915_private_t *dev_priv = ring->dev->dev_private;

       /* Every tail move must follow the sequence below */
        I915_WRITE(GEN6_BSD_SLEEP_PSMI_CONTROL,
                GEN6_BSD_SLEEP_PSMI_CONTROL_RC_ILDL_MESSAGE_MODIFY_MASK |
                GEN6_BSD_SLEEP_PSMI_CONTROL_RC_ILDL_MESSAGE_DISABLE);
        I915_WRITE(GEN6_BSD_RNCID, 0x0);

        if (wait_for((I915_READ(GEN6_BSD_SLEEP_PSMI_CONTROL) &
                GEN6_BSD_SLEEP_PSMI_CONTROL_IDLE_INDICATOR) == 0,
                50))
        DRM_ERROR("timed out waiting for IDLE Indicator\n");

        I915_WRITE_TAIL(ring, value);
        I915_WRITE(GEN6_BSD_SLEEP_PSMI_CONTROL,
                GEN6_BSD_SLEEP_PSMI_CONTROL_RC_ILDL_MESSAGE_MODIFY_MASK |
                GEN6_BSD_SLEEP_PSMI_CONTROL_RC_ILDL_MESSAGE_ENABLE);
}

static int gen6_ring_flush(struct intel_ring_buffer *ring,
                           u32 invalidate, u32 flush)
{
        uint32_t cmd;
        int ret;

        ret = intel_ring_begin(ring, 4);
        if (ret)
                return ret;

        cmd = MI_FLUSH_DW;
        if (invalidate & I915_GEM_GPU_DOMAINS)
                cmd |= MI_INVALIDATE_TLB | MI_INVALIDATE_BSD;
        intel_ring_emit(ring, cmd);
        intel_ring_emit(ring, 0);
        intel_ring_emit(ring, 0);
        intel_ring_emit(ring, MI_NOOP);
        intel_ring_advance(ring);
        return 0;
}

static int
gen6_ring_dispatch_execbuffer(struct intel_ring_buffer *ring,
                              u32 offset, u32 len)
{
        int ret;

        ret = intel_ring_begin(ring, 2);
        if (ret)
                return ret;

        intel_ring_emit(ring, MI_BATCH_BUFFER_START | MI_BATCH_NON_SECURE_I965);
        /* bit0-7 is the length on GEN6+ */
        intel_ring_emit(ring, offset);
        intel_ring_advance(ring);

        return 0;
}

static bool
gen6_render_ring_get_irq(struct intel_ring_buffer *ring)
{
        return gen6_ring_get_irq(ring,
                                 GT_USER_INTERRUPT,
                                 GEN6_RENDER_USER_INTERRUPT);
}

static void
gen6_render_ring_put_irq(struct intel_ring_buffer *ring)
{
        return gen6_ring_put_irq(ring,
                                 GT_USER_INTERRUPT,
                                 GEN6_RENDER_USER_INTERRUPT);
}

static bool
gen6_bsd_ring_get_irq(struct intel_ring_buffer *ring)
{
        return gen6_ring_get_irq(ring,
                                 GT_GEN6_BSD_USER_INTERRUPT,
                                 GEN6_BSD_USER_INTERRUPT);
}

static void
gen6_bsd_ring_put_irq(struct intel_ring_buffer *ring)
{
        return gen6_ring_put_irq(ring,
                                 GT_GEN6_BSD_USER_INTERRUPT,
                                 GEN6_BSD_USER_INTERRUPT);
}

/* ring buffer for Video Codec for Gen6+ */
static const struct intel_ring_buffer gen6_bsd_ring = {
        .name                   = "gen6 bsd ring",
        .id                     = RING_BSD,
        .mmio_base              = GEN6_BSD_RING_BASE,
        .size                   = 32 * PAGE_SIZE,
        .init                   = init_ring_common,
        .write_tail             = gen6_bsd_ring_write_tail,
        .flush                  = gen6_ring_flush,
        .add_request            = gen6_add_request,
        .get_seqno              = ring_get_seqno,
        .irq_get                = gen6_bsd_ring_get_irq,
        .irq_put                = gen6_bsd_ring_put_irq,
        .dispatch_execbuffer    = gen6_ring_dispatch_execbuffer,
        .sync_to                = gen6_bsd_ring_sync_to,
        .semaphore_register     = {MI_SEMAPHORE_SYNC_VR,
                                   MI_SEMAPHORE_SYNC_INVALID,
                                   MI_SEMAPHORE_SYNC_VB},
        .signal_mbox            = {GEN6_RVSYNC, GEN6_BVSYNC},
};

/* Blitter support (SandyBridge+) */

static bool
blt_ring_get_irq(struct intel_ring_buffer *ring)
{
        return gen6_ring_get_irq(ring,
                                 GT_BLT_USER_INTERRUPT,
                                 GEN6_BLITTER_USER_INTERRUPT);
}

static void
blt_ring_put_irq(struct intel_ring_buffer *ring)
{
        gen6_ring_put_irq(ring,
                          GT_BLT_USER_INTERRUPT,
                          GEN6_BLITTER_USER_INTERRUPT);
}


/* Workaround for some stepping of SNB,
 * each time when BLT engine ring tail moved,
 * the first command in the ring to be parsed
 * should be MI_BATCH_BUFFER_START
 */
#define NEED_BLT_WORKAROUND(dev) \
        (IS_GEN6(dev) && (dev->pdev->revision < 8))

static inline struct drm_i915_gem_object *
to_blt_workaround(struct intel_ring_buffer *ring)
{
        return ring->private;
}

static int blt_ring_init(struct intel_ring_buffer *ring)
{
        if (NEED_BLT_WORKAROUND(ring->dev)) {
                struct drm_i915_gem_object *obj;
                u32 *ptr;
                int ret;

                obj = i915_gem_alloc_object(ring->dev, 4096);
                if (obj == NULL)
                        return -ENOMEM;

                ret = i915_gem_object_pin(obj, 4096, true);
                if (ret) {
                        drm_gem_object_unreference(&obj->base);
                        return ret;
                }

                ptr = kmap(obj->pages[0]);
                *ptr++ = MI_BATCH_BUFFER_END;
                *ptr++ = MI_NOOP;
                kunmap(obj->pages[0]);

                ret = i915_gem_object_set_to_gtt_domain(obj, false);
                if (ret) {
                        i915_gem_object_unpin(obj);
                        drm_gem_object_unreference(&obj->base);
                        return ret;
                }

                ring->private = obj;
        }

        return init_ring_common(ring);
}

static int blt_ring_begin(struct intel_ring_buffer *ring,
                          int num_dwords)
{
        if (ring->private) {
                int ret = intel_ring_begin(ring, num_dwords+2);
                if (ret)
                        return ret;

                intel_ring_emit(ring, MI_BATCH_BUFFER_START);
                intel_ring_emit(ring, to_blt_workaround(ring)->gtt_offset);

                return 0;
        } else
                return intel_ring_begin(ring, 4);
}

static int blt_ring_flush(struct intel_ring_buffer *ring,
                          u32 invalidate, u32 flush)
{
        uint32_t cmd;
        int ret;

        ret = blt_ring_begin(ring, 4);
        if (ret)
                return ret;

        cmd = MI_FLUSH_DW;
        if (invalidate & I915_GEM_DOMAIN_RENDER)
                cmd |= MI_INVALIDATE_TLB;
        intel_ring_emit(ring, cmd);
        intel_ring_emit(ring, 0);
        intel_ring_emit(ring, 0);
        intel_ring_emit(ring, MI_NOOP);
        intel_ring_advance(ring);
        return 0;
}

static void blt_ring_cleanup(struct intel_ring_buffer *ring)
{
        if (!ring->private)
                return;

        i915_gem_object_unpin(ring->private);
        drm_gem_object_unreference(ring->private);
        ring->private = NULL;
}

static const struct intel_ring_buffer gen6_blt_ring = {
        .name                   = "blt ring",
        .id                     = RING_BLT,
        .mmio_base              = BLT_RING_BASE,
        .size                   = 32 * PAGE_SIZE,
        .init                   = blt_ring_init,
        .write_tail             = ring_write_tail,
        .flush                  = blt_ring_flush,
        .add_request            = gen6_add_request,
        .get_seqno              = ring_get_seqno,
        .irq_get                = blt_ring_get_irq,
        .irq_put                = blt_ring_put_irq,
        .dispatch_execbuffer    = gen6_ring_dispatch_execbuffer,
        .cleanup                = blt_ring_cleanup,
        .sync_to                = gen6_blt_ring_sync_to,
        .semaphore_register     = {MI_SEMAPHORE_SYNC_BR,
                                   MI_SEMAPHORE_SYNC_BV,
                                   MI_SEMAPHORE_SYNC_INVALID},
        .signal_mbox            = {GEN6_RBSYNC, GEN6_VBSYNC},
};

int intel_init_render_ring_buffer(struct drm_device *dev)
{
        drm_i915_private_t *dev_priv = dev->dev_private;
        struct intel_ring_buffer *ring = &dev_priv->ring[RCS];

        *ring = render_ring;
        if (INTEL_INFO(dev)->gen >= 6) {
                ring->add_request = gen6_add_request;
                ring->flush = gen6_render_ring_flush;
                ring->irq_get = gen6_render_ring_get_irq;
                ring->irq_put = gen6_render_ring_put_irq;
        } else if (IS_GEN5(dev)) {
                ring->add_request = pc_render_add_request;
                ring->get_seqno = pc_render_get_seqno;
        }

        if (!I915_NEED_GFX_HWS(dev)) {
                ring->status_page.page_addr = dev_priv->status_page_dmah->vaddr;
                memset(ring->status_page.page_addr, 0, PAGE_SIZE);
        }

        return intel_init_ring_buffer(dev, ring);
}

int intel_render_ring_init_dri(struct drm_device *dev, u64 start, u32 size)
{
        drm_i915_private_t *dev_priv = dev->dev_private;
        struct intel_ring_buffer *ring = &dev_priv->ring[RCS];

        *ring = render_ring;
        if (INTEL_INFO(dev)->gen >= 6) {
                ring->add_request = gen6_add_request;
                ring->irq_get = gen6_render_ring_get_irq;
                ring->irq_put = gen6_render_ring_put_irq;
        } else if (IS_GEN5(dev)) {
                ring->add_request = pc_render_add_request;
                ring->get_seqno = pc_render_get_seqno;
        }

        if (!I915_NEED_GFX_HWS(dev))
                ring->status_page.page_addr = dev_priv->status_page_dmah->vaddr;

        ring->dev = dev;
        INIT_LIST_HEAD(&ring->active_list);
        INIT_LIST_HEAD(&ring->request_list);
        INIT_LIST_HEAD(&ring->gpu_write_list);

        ring->size = size;
        ring->effective_size = ring->size;
        if (IS_I830(ring->dev))
                ring->effective_size -= 128;

        ring->map.offset = start;
        ring->map.size = size;
        ring->map.type = 0;
        ring->map.flags = 0;
        ring->map.mtrr = 0;

        drm_core_ioremap_wc(&ring->map, dev);
        if (ring->map.handle == NULL) {
                DRM_ERROR("can not ioremap virtual address for"
                          " ring buffer\n");
                return -ENOMEM;
        }

        ring->virtual_start = (void __force __iomem *)ring->map.handle;
        return 0;
}

int intel_init_bsd_ring_buffer(struct drm_device *dev)
{
        drm_i915_private_t *dev_priv = dev->dev_private;
        struct intel_ring_buffer *ring = &dev_priv->ring[VCS];

        if (IS_GEN6(dev) || IS_GEN7(dev))
                *ring = gen6_bsd_ring;
        else
                *ring = bsd_ring;

        return intel_init_ring_buffer(dev, ring);
}

int intel_init_blt_ring_buffer(struct drm_device *dev)
{
        drm_i915_private_t *dev_priv = dev->dev_private;
        struct intel_ring_buffer *ring = &dev_priv->ring[BCS];

        *ring = gen6_blt_ring;

        return intel_init_ring_buffer(dev, ring);
}