3 files changed, 45 insertions, 72 deletions

diff --git a/drivers/gpu/drm/radeon/r600_blit_kms.c b/drivers/gpu/drm/radeon/r600_blit_kms.c
index 2d7d16e14f9e..ec49dada887d 100644
--- a/drivers/gpu/drm/radeon/r600_blit_kms.c
+++ b/drivers/gpu/drm/radeon/r600_blit_kms.c
@@ -541,9 +541,6 @@ int r600_vb_ib_get(struct radeon_device *rdev)
 void r600_vb_ib_put(struct radeon_device *rdev)
 {
         radeon_fence_emit(rdev, rdev->r600_blit.vb_ib->fence);
-        mutex_lock(&rdev->ib_pool.mutex);
-        list_add_tail(&rdev->r600_blit.vb_ib->list, &rdev->ib_pool.scheduled_ibs);
-        mutex_unlock(&rdev->ib_pool.mutex);
         radeon_ib_free(rdev, &rdev->r600_blit.vb_ib);
 }
 
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 993cdf20d8e6..9f35beed13e8 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -97,6 +97,7 @@ extern int radeon_audio;
  * symbol;
  */
 #define RADEON_MAX_USEC_TIMEOUT         100000  /* 100 ms */
+/* RADEON_IB_POOL_SIZE must be a power of 2 */
 #define RADEON_IB_POOL_SIZE             16
 #define RADEON_DEBUGFS_MAX_NUM_FILES    32
 #define RADEONFB_CONN_LIMIT             4
@@ -371,11 +372,12 @@ void radeon_irq_kms_sw_irq_put(struct radeon_device *rdev);
  */
 struct radeon_ib {
         struct list_head        list;
-        unsigned long           idx;
+        unsigned                idx;
         uint64_t                gpu_addr;
         struct radeon_fence     *fence;
-        uint32_t        *ptr;
+        uint32_t                *ptr;
         uint32_t                length_dw;
+        bool                    free;
 };
 
 /*
@@ -385,11 +387,10 @@ struct radeon_ib {
 struct radeon_ib_pool {
         struct mutex            mutex;
         struct radeon_bo        *robj;
-        struct list_head        scheduled_ibs;
         struct list_head        bogus_ib;
         struct radeon_ib        ibs[RADEON_IB_POOL_SIZE];
         bool                    ready;
-        DECLARE_BITMAP(alloc_bm, RADEON_IB_POOL_SIZE);
+        unsigned                head_id;
 };
 
 struct radeon_cp {
diff --git a/drivers/gpu/drm/radeon/radeon_ring.c b/drivers/gpu/drm/radeon/radeon_ring.c
index e3bee59ef6c3..38fa14429320 100644
--- a/drivers/gpu/drm/radeon/radeon_ring.c
+++ b/drivers/gpu/drm/radeon/radeon_ring.c
@@ -71,68 +71,55 @@ int radeon_ib_get(struct radeon_device *rdev, struct radeon_ib **ib)
 {
         struct radeon_fence *fence;
         struct radeon_ib *nib;
-        unsigned long i;
-        int r = 0;
+        int r = 0, i, c;
 
         *ib = NULL;
         r = radeon_fence_create(rdev, &fence);
         if (r) {
-                DRM_ERROR("failed to create fence for new IB\n");
+                dev_err(rdev->dev, "failed to create fence for new IB\n");
                 return r;
         }
         mutex_lock(&rdev->ib_pool.mutex);
-        i = find_first_zero_bit(rdev->ib_pool.alloc_bm, RADEON_IB_POOL_SIZE);
-        if (i < RADEON_IB_POOL_SIZE) {
-                set_bit(i, rdev->ib_pool.alloc_bm);
-                rdev->ib_pool.ibs[i].length_dw = 0;
-                *ib = &rdev->ib_pool.ibs[i];
-                mutex_unlock(&rdev->ib_pool.mutex);
-                goto out;
+        for (i = rdev->ib_pool.head_id, c = 0, nib = NULL; c < RADEON_IB_POOL_SIZE; c++, i++) {
+                i &= (RADEON_IB_POOL_SIZE - 1);
+                if (rdev->ib_pool.ibs[i].free) {
+                        nib = &rdev->ib_pool.ibs[i];
+                        break;
+                }
         }
-        if (list_empty(&rdev->ib_pool.scheduled_ibs)) {
-                /* we go do nothings here */
+        if (nib == NULL) {
+                /* This should never happen, it means we allocated all
+                 * IB and haven't scheduled one yet, return EBUSY to
+                 * userspace hoping that on ioctl recall we get better
+                 * luck
+                 */
+                dev_err(rdev->dev, "no free indirect buffer !\n");
                 mutex_unlock(&rdev->ib_pool.mutex);
-                DRM_ERROR("all IB allocated none scheduled.\n");
-                r = -EINVAL;
-                goto out;
+                radeon_fence_unref(&fence);
+                return -EBUSY;
         }
-        /* get the first ib on the scheduled list */
-        nib = list_entry(rdev->ib_pool.scheduled_ibs.next,
-                         struct radeon_ib, list);
-        if (nib->fence == NULL) {
-                /* we go do nothings here */
+        rdev->ib_pool.head_id = (nib->idx + 1) & (RADEON_IB_POOL_SIZE - 1);
+        nib->free = false;
+        if (nib->fence) {
                 mutex_unlock(&rdev->ib_pool.mutex);
-                DRM_ERROR("IB %lu scheduled without a fence.\n", nib->idx);
-                r = -EINVAL;
-                goto out;
-        }
-        mutex_unlock(&rdev->ib_pool.mutex);
-
-        r = radeon_fence_wait(nib->fence, false);
-        if (r) {
-                DRM_ERROR("radeon: IB(%lu:0x%016lX:%u)\n", nib->idx,
-                          (unsigned long)nib->gpu_addr, nib->length_dw);
-                DRM_ERROR("radeon: GPU lockup detected, fail to get a IB\n");
-                goto out;
+                r = radeon_fence_wait(nib->fence, false);
+                if (r) {
+                        dev_err(rdev->dev, "error waiting fence of IB(%u:0x%016lX:%u)\n",
+                                nib->idx, (unsigned long)nib->gpu_addr, nib->length_dw);
+                        mutex_lock(&rdev->ib_pool.mutex);
+                        nib->free = true;
+                        mutex_unlock(&rdev->ib_pool.mutex);
+                        radeon_fence_unref(&fence);
+                        return r;
+                }
+                mutex_lock(&rdev->ib_pool.mutex);
         }
         radeon_fence_unref(&nib->fence);
-
+        nib->fence = fence;
         nib->length_dw = 0;
-
-        /* scheduled list is accessed here */
-        mutex_lock(&rdev->ib_pool.mutex);
-        list_del(&nib->list);
-        INIT_LIST_HEAD(&nib->list);
         mutex_unlock(&rdev->ib_pool.mutex);
-
         *ib = nib;
-out:
-        if (r) {
-                radeon_fence_unref(&fence);
-        } else {
-                (*ib)->fence = fence;
-        }
-        return r;
+        return 0;
 }
 
 void radeon_ib_free(struct radeon_device *rdev, struct radeon_ib **ib)
@@ -144,18 +131,7 @@ void radeon_ib_free(struct radeon_device *rdev, struct radeon_ib **ib)
                 return;
         }
         mutex_lock(&rdev->ib_pool.mutex);
-        if (!list_empty(&tmp->list) && !radeon_fence_signaled(tmp->fence)) {
-                /* IB is scheduled & not signaled don't do anythings */
-                mutex_unlock(&rdev->ib_pool.mutex);
-                return;
-        }
-        list_del(&tmp->list);
-        INIT_LIST_HEAD(&tmp->list);
-        if (tmp->fence)
-                radeon_fence_unref(&tmp->fence);
-
-        tmp->length_dw = 0;
-        clear_bit(tmp->idx, rdev->ib_pool.alloc_bm);
+        tmp->free = true;
         mutex_unlock(&rdev->ib_pool.mutex);
 }
 
@@ -165,7 +141,7 @@ int radeon_ib_schedule(struct radeon_device *rdev, struct radeon_ib *ib)
 
         if (!ib->length_dw || !rdev->cp.ready) {
                 /* TODO: Nothings in the ib we should report. */
-                DRM_ERROR("radeon: couldn't schedule IB(%lu).\n", ib->idx);
+                DRM_ERROR("radeon: couldn't schedule IB(%u).\n", ib->idx);
                 return -EINVAL;
         }
 
@@ -178,7 +154,8 @@ int radeon_ib_schedule(struct radeon_device *rdev, struct radeon_ib *ib)
         radeon_ring_ib_execute(rdev, ib);
         radeon_fence_emit(rdev, ib->fence);
         mutex_lock(&rdev->ib_pool.mutex);
-        list_add_tail(&ib->list, &rdev->ib_pool.scheduled_ibs);
+        /* once scheduled IB is considered free and protected by the fence */
+        ib->free = true;
         mutex_unlock(&rdev->ib_pool.mutex);
         radeon_ring_unlock_commit(rdev);
         return 0;
@@ -195,7 +172,6 @@ int radeon_ib_pool_init(struct radeon_device *rdev)
                 return 0;
         INIT_LIST_HEAD(&rdev->ib_pool.bogus_ib);
         /* Allocate 1M object buffer */
-        INIT_LIST_HEAD(&rdev->ib_pool.scheduled_ibs);
         r = radeon_bo_create(rdev, NULL,  RADEON_IB_POOL_SIZE*64*1024,
                                 true, RADEON_GEM_DOMAIN_GTT,
                                 &rdev->ib_pool.robj);
@@ -226,9 +202,9 @@ int radeon_ib_pool_init(struct radeon_device *rdev)
                 rdev->ib_pool.ibs[i].ptr = ptr + offset;
                 rdev->ib_pool.ibs[i].idx = i;
                 rdev->ib_pool.ibs[i].length_dw = 0;
-                INIT_LIST_HEAD(&rdev->ib_pool.ibs[i].list);
+                rdev->ib_pool.ibs[i].free = true;
         }
-        bitmap_zero(rdev->ib_pool.alloc_bm, RADEON_IB_POOL_SIZE);
+        rdev->ib_pool.head_id = 0;
         rdev->ib_pool.ready = true;
         DRM_INFO("radeon: ib pool ready.\n");
         if (radeon_debugfs_ib_init(rdev)) {
@@ -246,7 +222,6 @@ void radeon_ib_pool_fini(struct radeon_device *rdev)
         }
         mutex_lock(&rdev->ib_pool.mutex);
         radeon_ib_bogus_cleanup(rdev);
-        bitmap_zero(rdev->ib_pool.alloc_bm, RADEON_IB_POOL_SIZE);
         if (rdev->ib_pool.robj) {
                 r = radeon_bo_reserve(rdev->ib_pool.robj, false);
                 if (likely(r == 0)) {
@@ -395,7 +370,7 @@ static int radeon_debugfs_ib_info(struct seq_file *m, void *data)
         if (ib == NULL) {
                 return 0;
         }
-        seq_printf(m, "IB %04lu\n", ib->idx);
+        seq_printf(m, "IB %04u\n", ib->idx);
         seq_printf(m, "IB fence %p\n", ib->fence);
         seq_printf(m, "IB size %05u dwords\n", ib->length_dw);
         for (i = 0; i < ib->length_dw; i++) {