drm/i915: implement BSD ring buffer V2

The BSD (bit stream decoder) ring is used for accessing the BSD engine
which decodes video bitstream for H.264 and VC1 on G45+.  It is
asynchronous with the render ring and has access to separate parts of
the GPU from it, though the render cache is coherent between the two.

Signed-off-by: Zou Nan hai <nanhai.zou@intel.com>
Signed-off-by: Xiang Hai hao <haihao.xiang@intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index f485880300ce89b0542db18106b9944d5bfda143..1dbed700800e622311488b7b0809efec435e7fff 100644 (file)
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -130,6 +130,8 @@ static int i915_dma_cleanup(struct drm_device * dev)
                drm_irq_uninstall(dev);
 
        intel_cleanup_ring_buffer(dev, &dev_priv->render_ring);
+       if (HAS_BSD(dev))
+               intel_cleanup_ring_buffer(dev, &dev_priv->bsd_ring);
 
        /* Clear the HWS virtual address at teardown */
        if (I915_NEED_GFX_HWS(dev))

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 3f35989ba74c8808bf389b8bebef268ff7bd5ffb..6bc0fc080f2b48aa30660bcf0f33a297b531c762 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -235,6 +235,7 @@ typedef struct drm_i915_private {
 
        struct pci_dev *bridge_dev;
        struct intel_ring_buffer render_ring;
+       struct intel_ring_buffer bsd_ring;
 
        drm_dma_handle_t *status_page_dmah;
        void *hw_status_page;
@@ -1121,6 +1122,7 @@ extern int intel_trans_dp_port_sel (struct drm_crtc *crtc);
                         (dev)->pci_device == 0x2A42 ||         \
                         (dev)->pci_device == 0x2E42)
 
+#define HAS_BSD(dev)            (IS_IRONLAKE(dev) || IS_G4X(dev))
 #define I915_NEED_GFX_HWS(dev) (INTEL_INFO(dev)->need_gfx_hws)
 
 /* With the 945 and later, Y tiling got adjusted so that it was 32 128-byte

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index af664ba923c5c5cafab9022a8dde829a2e3ff45d..c51495f1571844b8f302d3ec819a0d49a6a60888 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1730,7 +1730,7 @@ i915_seqno_passed(uint32_t seq1, uint32_t seq2)
 
 uint32_t
 i915_get_gem_seqno(struct drm_device *dev,
-               struct intel_ring_buffer *ring)
+                  struct intel_ring_buffer *ring)
 {
        return ring->get_gem_seqno(dev, ring);
 }
@@ -1792,8 +1792,13 @@ i915_gem_retire_work_handler(struct work_struct *work)
        mutex_lock(&dev->struct_mutex);
        i915_gem_retire_requests(dev, &dev_priv->render_ring);
 
+       if (HAS_BSD(dev))
+               i915_gem_retire_requests(dev, &dev_priv->bsd_ring);
+
        if (!dev_priv->mm.suspended &&
-                       (!list_empty(&dev_priv->render_ring.request_list)))
+               (!list_empty(&dev_priv->render_ring.request_list) ||
+                       (HAS_BSD(dev) &&
+                        !list_empty(&dev_priv->bsd_ring.request_list))))
                queue_delayed_work(dev_priv->wq, &dev_priv->mm.retire_work, HZ);
        mutex_unlock(&dev->struct_mutex);
 }
@@ -1883,6 +1888,11 @@ i915_gem_flush(struct drm_device *dev,
        dev_priv->render_ring.flush(dev, &dev_priv->render_ring,
                        invalidate_domains,
                        flush_domains);
+
+       if (HAS_BSD(dev))
+               dev_priv->bsd_ring.flush(dev, &dev_priv->bsd_ring,
+                               invalidate_domains,
+                               flush_domains);
 }
 
 static void
@@ -2039,12 +2049,14 @@ i915_gpu_idle(struct drm_device *dev)
 {
        drm_i915_private_t *dev_priv = dev->dev_private;
        bool lists_empty;
-       uint32_t seqno;
+       uint32_t seqno1, seqno2;
        int ret;
 
        spin_lock(&dev_priv->mm.active_list_lock);
-       lists_empty = list_empty(&dev_priv->mm.flushing_list) &&
-                     list_empty(&dev_priv->render_ring.active_list);
+       lists_empty = (list_empty(&dev_priv->mm.flushing_list) &&
+                      list_empty(&dev_priv->render_ring.active_list) &&
+                      (!HAS_BSD(dev) ||
+                       list_empty(&dev_priv->bsd_ring.active_list)));
        spin_unlock(&dev_priv->mm.active_list_lock);
 
        if (lists_empty)
@@ -2052,11 +2064,23 @@ i915_gpu_idle(struct drm_device *dev)
 
        /* Flush everything onto the inactive list. */
        i915_gem_flush(dev, I915_GEM_GPU_DOMAINS, I915_GEM_GPU_DOMAINS);
-       seqno = i915_add_request(dev, NULL, I915_GEM_GPU_DOMAINS,
+       seqno1 = i915_add_request(dev, NULL, I915_GEM_GPU_DOMAINS,
                        &dev_priv->render_ring);
-       if (seqno == 0)
+       if (seqno1 == 0)
                return -ENOMEM;
-       ret = i915_wait_request(dev, seqno, &dev_priv->render_ring);
+       ret = i915_wait_request(dev, seqno1, &dev_priv->render_ring);
+
+       if (HAS_BSD(dev)) {
+               seqno2 = i915_add_request(dev, NULL, I915_GEM_GPU_DOMAINS,
+                               &dev_priv->bsd_ring);
+               if (seqno2 == 0)
+                       return -ENOMEM;
+
+               ret = i915_wait_request(dev, seqno2, &dev_priv->bsd_ring);
+               if (ret)
+                       return ret;
+       }
+
 
        return ret;
 }
@@ -2071,7 +2095,9 @@ i915_gem_evict_everything(struct drm_device *dev)
        spin_lock(&dev_priv->mm.active_list_lock);
        lists_empty = (list_empty(&dev_priv->mm.inactive_list) &&
                       list_empty(&dev_priv->mm.flushing_list) &&
-                      list_empty(&dev_priv->render_ring.active_list));
+                      list_empty(&dev_priv->render_ring.active_list) &&
+                      (!HAS_BSD(dev)
+                       || list_empty(&dev_priv->bsd_ring.active_list)));
        spin_unlock(&dev_priv->mm.active_list_lock);
 
        if (lists_empty)
@@ -2091,7 +2117,9 @@ i915_gem_evict_everything(struct drm_device *dev)
        spin_lock(&dev_priv->mm.active_list_lock);
        lists_empty = (list_empty(&dev_priv->mm.inactive_list) &&
                       list_empty(&dev_priv->mm.flushing_list) &&
-                      list_empty(&dev_priv->render_ring.active_list));
+                      list_empty(&dev_priv->render_ring.active_list) &&
+                      (!HAS_BSD(dev)
+                       || list_empty(&dev_priv->bsd_ring.active_list)));
        spin_unlock(&dev_priv->mm.active_list_lock);
        BUG_ON(!lists_empty);
 
@@ -2106,9 +2134,13 @@ i915_gem_evict_something(struct drm_device *dev, int min_size)
        int ret;
 
        struct intel_ring_buffer *render_ring = &dev_priv->render_ring;
+       struct intel_ring_buffer *bsd_ring = &dev_priv->bsd_ring;
        for (;;) {
                i915_gem_retire_requests(dev, render_ring);
 
+               if (HAS_BSD(dev))
+                       i915_gem_retire_requests(dev, bsd_ring);
+
                /* If there's an inactive buffer available now, grab it
                 * and be done.
                 */
@@ -2146,6 +2178,21 @@ i915_gem_evict_something(struct drm_device *dev, int min_size)
                        continue;
                }
 
+               if (HAS_BSD(dev) && !list_empty(&bsd_ring->request_list)) {
+                       struct drm_i915_gem_request *request;
+
+                       request = list_first_entry(&bsd_ring->request_list,
+                                                  struct drm_i915_gem_request,
+                                                  list);
+
+                       ret = i915_wait_request(dev,
+                                       request->seqno, request->ring);
+                       if (ret)
+                               return ret;
+
+                       continue;
+               }
+
                /* If we didn't have anything on the request list but there
                 * are buffers awaiting a flush, emit one and try again.
                 * When we wait on it, those buffers waiting for that flush
@@ -3641,6 +3688,16 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
        DRM_INFO("buffers_ptr %d buffer_count %d len %08x\n",
                  (int) args->buffers_ptr, args->buffer_count, args->batch_len);
 #endif
+       if (args->flags & I915_EXEC_BSD) {
+               if (!HAS_BSD(dev)) {
+                       DRM_ERROR("execbuf with wrong flag\n");
+                       return -EINVAL;
+               }
+               ring = &dev_priv->bsd_ring;
+       } else {
+               ring = &dev_priv->render_ring;
+       }
+
 
        if (args->buffer_count < 1) {
                DRM_ERROR("execbuf with %d buffers\n", args->buffer_count);
@@ -3694,8 +3751,6 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
                goto pre_mutex_err;
        }
 
-       ring = &dev_priv->render_ring;
-
        /* Look up object handles */
        flips = 0;
        for (i = 0; i < args->buffer_count; i++) {
@@ -3834,6 +3889,10 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
                                        dev->flush_domains,
                                        &dev_priv->render_ring);
 
+                       if (HAS_BSD(dev))
+                               (void)i915_add_request(dev, file_priv,
+                                               dev->flush_domains,
+                                               &dev_priv->bsd_ring);
                }
        }
 
@@ -4267,6 +4326,9 @@ i915_gem_busy_ioctl(struct drm_device *dev, void *data,
         */
        i915_gem_retire_requests(dev, &dev_priv->render_ring);
 
+       if (HAS_BSD(dev))
+               i915_gem_retire_requests(dev, &dev_priv->bsd_ring);
+
        obj_priv = to_intel_bo(obj);
        /* Don't count being on the flushing list against the object being
         * done.  Otherwise, a buffer left on the flushing list but not getting
@@ -4433,7 +4495,9 @@ i915_gem_idle(struct drm_device *dev)
        mutex_lock(&dev->struct_mutex);
 
        if (dev_priv->mm.suspended ||
-                       dev_priv->render_ring.gem_object == NULL) {
+                       (dev_priv->render_ring.gem_object == NULL) ||
+                       (HAS_BSD(dev) &&
+                        dev_priv->bsd_ring.gem_object == NULL)) {
                mutex_unlock(&dev->struct_mutex);
                return 0;
        }
@@ -4550,6 +4614,10 @@ i915_gem_init_ringbuffer(struct drm_device *dev)
                        return ret;
        }
        ret = intel_init_ring_buffer(dev, &dev_priv->render_ring);
+       if (!ret && HAS_BSD(dev)) {
+               dev_priv->bsd_ring = bsd_ring;
+               ret = intel_init_ring_buffer(dev, &dev_priv->bsd_ring);
+       }
        return ret;
 }
 
@@ -4559,6 +4627,8 @@ i915_gem_cleanup_ringbuffer(struct drm_device *dev)
        drm_i915_private_t *dev_priv = dev->dev_private;
 
        intel_cleanup_ring_buffer(dev, &dev_priv->render_ring);
+       if (HAS_BSD(dev))
+               intel_cleanup_ring_buffer(dev, &dev_priv->bsd_ring);
        if (HAS_PIPE_CONTROL(dev))
                i915_gem_cleanup_pipe_control(dev);
 }
@@ -4589,11 +4659,13 @@ i915_gem_entervt_ioctl(struct drm_device *dev, void *data,
 
        spin_lock(&dev_priv->mm.active_list_lock);
        BUG_ON(!list_empty(&dev_priv->render_ring.active_list));
+       BUG_ON(HAS_BSD(dev) && !list_empty(&dev_priv->bsd_ring.active_list));
        spin_unlock(&dev_priv->mm.active_list_lock);
 
        BUG_ON(!list_empty(&dev_priv->mm.flushing_list));
        BUG_ON(!list_empty(&dev_priv->mm.inactive_list));
        BUG_ON(!list_empty(&dev_priv->render_ring.request_list));
+       BUG_ON(HAS_BSD(dev) && !list_empty(&dev_priv->bsd_ring.request_list));
        mutex_unlock(&dev->struct_mutex);
 
        drm_irq_install(dev);
@@ -4638,6 +4710,10 @@ i915_gem_load(struct drm_device *dev)
        INIT_LIST_HEAD(&dev_priv->mm.fence_list);
        INIT_LIST_HEAD(&dev_priv->render_ring.active_list);
        INIT_LIST_HEAD(&dev_priv->render_ring.request_list);
+       if (HAS_BSD(dev)) {
+               INIT_LIST_HEAD(&dev_priv->bsd_ring.active_list);
+               INIT_LIST_HEAD(&dev_priv->bsd_ring.request_list);
+       }
        for (i = 0; i < 16; i++)
                INIT_LIST_HEAD(&dev_priv->fence_regs[i].lru_list);
        INIT_DELAYED_WORK(&dev_priv->mm.retire_work,
@@ -4874,6 +4950,8 @@ i915_gpu_is_active(struct drm_device *dev)
        spin_lock(&dev_priv->mm.active_list_lock);
        lists_empty = list_empty(&dev_priv->mm.flushing_list) &&
                      list_empty(&dev_priv->render_ring.active_list);
+       if (HAS_BSD(dev))
+               lists_empty &= list_empty(&dev_priv->bsd_ring.active_list);
        spin_unlock(&dev_priv->mm.active_list_lock);
 
        return !lists_empty;
@@ -4920,6 +4998,9 @@ rescan:
                spin_unlock(&shrink_list_lock);
                i915_gem_retire_requests(dev, &dev_priv->render_ring);
 
+               if (HAS_BSD(dev))
+                       i915_gem_retire_requests(dev, &dev_priv->bsd_ring);
+
                list_for_each_entry_safe(obj_priv, next_obj,
                                         &dev_priv->mm.inactive_list,
                                         list) {

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 8a667f1db75ab40db02a80705d0fb1fc198e5719..0a3a5806a12ed58b66235ab7fc831bae3fd82505 100644 (file)
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -53,7 +53,7 @@
         I915_RENDER_COMMAND_PARSER_ERROR_INTERRUPT)
 
 /** Interrupts that we mask and unmask at runtime. */
-#define I915_INTERRUPT_ENABLE_VAR (I915_USER_INTERRUPT)
+#define I915_INTERRUPT_ENABLE_VAR (I915_USER_INTERRUPT | I915_BSD_USER_INTERRUPT)
 
 #define I915_PIPE_VBLANK_STATUS        (PIPE_START_VBLANK_INTERRUPT_STATUS |\
                                 PIPE_VBLANK_INTERRUPT_STATUS)
@@ -362,6 +362,9 @@ irqreturn_t ironlake_irq_handler(struct drm_device *dev)
                dev_priv->hangcheck_count = 0;
                mod_timer(&dev_priv->hangcheck_timer, jiffies + DRM_I915_HANGCHECK_PERIOD);
        }
+       if (gt_iir & GT_BSD_USER_INTERRUPT)
+               DRM_WAKEUP(&dev_priv->bsd_ring.irq_queue);
+
 
        if (de_iir & DE_GSE)
                ironlake_opregion_gse_intr(dev);
@@ -944,6 +947,9 @@ irqreturn_t i915_driver_irq_handler(DRM_IRQ_ARGS)
                        mod_timer(&dev_priv->hangcheck_timer, jiffies + DRM_I915_HANGCHECK_PERIOD);
                }
 
+               if (HAS_BSD(dev) && (iir & I915_BSD_USER_INTERRUPT))
+                       DRM_WAKEUP(&dev_priv->bsd_ring.irq_queue);
+
                if (iir & I915_DISPLAY_PLANE_A_FLIP_PENDING_INTERRUPT)
                        intel_prepare_page_flip(dev, 0);
 
@@ -1297,7 +1303,7 @@ static int ironlake_irq_postinstall(struct drm_device *dev)
        /* enable kind of interrupts always enabled */
        u32 display_mask = DE_MASTER_IRQ_CONTROL | DE_GSE | DE_PCH_EVENT |
                           DE_PLANEA_FLIP_DONE | DE_PLANEB_FLIP_DONE;
-       u32 render_mask = GT_PIPE_NOTIFY;
+       u32 render_mask = GT_PIPE_NOTIFY | GT_BSD_USER_INTERRUPT;
        u32 hotplug_mask = SDE_CRT_HOTPLUG | SDE_PORTB_HOTPLUG |
                           SDE_PORTC_HOTPLUG | SDE_PORTD_HOTPLUG;
 
@@ -1376,6 +1382,9 @@ int i915_driver_irq_postinstall(struct drm_device *dev)
 
        DRM_INIT_WAITQUEUE(&dev_priv->render_ring.irq_queue);
 
+       if (HAS_BSD(dev))
+               DRM_INIT_WAITQUEUE(&dev_priv->bsd_ring.irq_queue);
+
        dev_priv->vblank_pipe = DRM_I915_VBLANK_PIPE_A | DRM_I915_VBLANK_PIPE_B;
 
        if (HAS_PCH_SPLIT(dev))

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index f3e39cc46f0dd0c4e9dba3c130a05ce1dc5986cf..784cf3c914e9293e0e7ed3e49d64d51667e6c41c 100644 (file)
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -334,6 +334,7 @@
 #define   I915_DEBUG_INTERRUPT                         (1<<2)
 #define   I915_USER_INTERRUPT                          (1<<1)
 #define   I915_ASLE_INTERRUPT                          (1<<0)
+#define   I915_BSD_USER_INTERRUPT                      (1<<25)
 #define EIR            0x020b0
 #define EMR            0x020b4
 #define ESR            0x020b8
@@ -368,6 +369,17 @@
 #define BB_ADDR                0x02140 /* 8 bytes */
 #define GFX_FLSH_CNTL  0x02170 /* 915+ only */
 
+/*
+ * BSD (bit stream decoder instruction and interrupt control register defines
+ * (G4X and Ironlake only)
+ */
+
+#define BSD_RING_TAIL          0x04030
+#define BSD_RING_HEAD          0x04034
+#define BSD_RING_START         0x04038
+#define BSD_RING_CTL           0x0403c
+#define BSD_RING_ACTHD         0x04074
+#define BSD_HWS_PGA            0x04080
 
 /*
  * Framebuffer compression (915+ only)
@@ -2355,6 +2367,8 @@
 #define GT_PIPE_NOTIFY         (1 << 4)
 #define GT_SYNC_STATUS          (1 << 2)
 #define GT_USER_INTERRUPT       (1 << 0)
+#define GT_BSD_USER_INTERRUPT   (1 << 5)
+
 
 #define GTISR   0x44010
 #define GTIMR   0x44014

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 5715c4d8cce9c7f8192571ec90b729137cd913f1..f6b84fe8099a7cfb14386e284da5c6b6b18b057f 100644 (file)
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -340,6 +340,119 @@ static void render_setup_status_page(struct drm_device *dev,
 
 }
 
+void
+bsd_ring_flush(struct drm_device *dev,
+               struct intel_ring_buffer *ring,
+               u32     invalidate_domains,
+               u32     flush_domains)
+{
+       intel_ring_begin(dev, ring, 8);
+       intel_ring_emit(dev, ring, MI_FLUSH);
+       intel_ring_emit(dev, ring, MI_NOOP);
+       intel_ring_advance(dev, ring);
+}
+
+static inline unsigned int bsd_ring_get_head(struct drm_device *dev,
+               struct intel_ring_buffer *ring)
+{
+       drm_i915_private_t *dev_priv = dev->dev_private;
+       return I915_READ(BSD_RING_HEAD) & HEAD_ADDR;
+}
+
+static inline unsigned int bsd_ring_get_tail(struct drm_device *dev,
+               struct intel_ring_buffer *ring)
+{
+       drm_i915_private_t *dev_priv = dev->dev_private;
+       return I915_READ(BSD_RING_TAIL) & TAIL_ADDR;
+}
+
+static inline unsigned int bsd_ring_get_active_head(struct drm_device *dev,
+               struct intel_ring_buffer *ring)
+{
+       drm_i915_private_t *dev_priv = dev->dev_private;
+       return I915_READ(BSD_RING_ACTHD);
+}
+
+static inline void bsd_ring_advance_ring(struct drm_device *dev,
+               struct intel_ring_buffer *ring)
+{
+       drm_i915_private_t *dev_priv = dev->dev_private;
+       I915_WRITE(BSD_RING_TAIL, ring->tail);
+}
+
+static int init_bsd_ring(struct drm_device *dev,
+               struct intel_ring_buffer *ring)
+{
+       return init_ring_common(dev, ring);
+}
+
+static u32
+bsd_ring_add_request(struct drm_device *dev,
+               struct intel_ring_buffer *ring,
+               struct drm_file *file_priv,
+               u32 flush_domains)
+{
+       u32 seqno;
+       seqno = intel_ring_get_seqno(dev, ring);
+       intel_ring_begin(dev, ring, 4);
+       intel_ring_emit(dev, ring, MI_STORE_DWORD_INDEX);
+       intel_ring_emit(dev, ring,
+                       I915_GEM_HWS_INDEX << MI_STORE_DWORD_INDEX_SHIFT);
+       intel_ring_emit(dev, ring, seqno);
+       intel_ring_emit(dev, ring, MI_USER_INTERRUPT);
+       intel_ring_advance(dev, ring);
+
+       DRM_DEBUG_DRIVER("%s %d\n", ring->name, seqno);
+
+       return seqno;
+}
+
+static void bsd_setup_status_page(struct drm_device *dev,
+               struct  intel_ring_buffer *ring)
+{
+       drm_i915_private_t *dev_priv = dev->dev_private;
+       I915_WRITE(BSD_HWS_PGA, ring->status_page.gfx_addr);
+       I915_READ(BSD_HWS_PGA);
+}
+
+static void
+bsd_ring_get_user_irq(struct drm_device *dev,
+               struct intel_ring_buffer *ring)
+{
+       /* do nothing */
+}
+static void
+bsd_ring_put_user_irq(struct drm_device *dev,
+               struct intel_ring_buffer *ring)
+{
+       /* do nothing */
+}
+
+static u32
+bsd_ring_get_gem_seqno(struct drm_device *dev,
+               struct intel_ring_buffer *ring)
+{
+       return intel_read_status_page(ring, I915_GEM_HWS_INDEX);
+}
+
+static int
+bsd_ring_dispatch_gem_execbuffer(struct drm_device *dev,
+               struct intel_ring_buffer *ring,
+               struct drm_i915_gem_execbuffer2 *exec,
+               struct drm_clip_rect *cliprects,
+               uint64_t exec_offset)
+{
+       uint32_t exec_start;
+       exec_start = (uint32_t) exec_offset + exec->batch_start_offset;
+       intel_ring_begin(dev, ring, 2);
+       intel_ring_emit(dev, ring, MI_BATCH_BUFFER_START |
+                       (2 << 6) | MI_BATCH_NON_SECURE_I965);
+       intel_ring_emit(dev, ring, exec_start);
+       intel_ring_advance(dev, ring);
+       return 0;
+}
+
+
 static int
 render_ring_dispatch_gem_execbuffer(struct drm_device *dev,
                struct intel_ring_buffer *ring,
@@ -588,6 +701,7 @@ int intel_wait_ring_buffer(struct drm_device *dev,
                        if (master_priv->sarea_priv)
                                master_priv->sarea_priv->perf_boxes |= I915_BOX_WAIT;
                }
+
                yield();
        } while (!time_after(jiffies, end));
        trace_i915_ring_wait_end (dev);
@@ -682,3 +796,42 @@ struct intel_ring_buffer render_ring = {
        .status_page            = {NULL, 0, NULL},
        .map                    = {0,}
 };
+
+/* ring buffer for bit-stream decoder */
+
+struct intel_ring_buffer bsd_ring = {
+       .name                   = "bsd ring",
+       .regs                   = {
+               .ctl = BSD_RING_CTL,
+               .head = BSD_RING_HEAD,
+               .tail = BSD_RING_TAIL,
+               .start = BSD_RING_START
+       },
+       .ring_flag              = I915_EXEC_BSD,
+       .size                   = 32 * PAGE_SIZE,
+       .alignment              = PAGE_SIZE,
+       .virtual_start          = NULL,
+       .dev                    = NULL,
+       .gem_object             = NULL,
+       .head                   = 0,
+       .tail                   = 0,
+       .space                  = 0,
+       .next_seqno             = 1,
+       .user_irq_refcount      = 0,
+       .irq_gem_seqno          = 0,
+       .waiting_gem_seqno      = 0,
+       .setup_status_page      = bsd_setup_status_page,
+       .init                   = init_bsd_ring,
+       .get_head               = bsd_ring_get_head,
+       .get_tail               = bsd_ring_get_tail,
+       .get_active_head        = bsd_ring_get_active_head,
+       .advance_ring           = bsd_ring_advance_ring,
+       .flush                  = bsd_ring_flush,
+       .add_request            = bsd_ring_add_request,
+       .get_gem_seqno          = bsd_ring_get_gem_seqno,
+       .user_irq_get           = bsd_ring_get_user_irq,
+       .user_irq_put           = bsd_ring_put_user_irq,
+       .dispatch_gem_execbuffer = bsd_ring_dispatch_gem_execbuffer,
+       .status_page            = {NULL, 0, NULL},
+       .map                    = {0,}
+};