drm/radeon: fix CP semaphores on CIK

The CP semaphore queue on CIK has a bug that triggers if uncompleted
waits use the same address while a signal is still pending. Work around
this by using different addresses for each sync.

Signed-off-by: Christian König <christian.koenig@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

3 files changed, 20 insertions, 5 deletions

diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 4a8ac1cd6b4c..024db37b1832 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -135,6 +135,9 @@ extern int radeon_hard_reset;
 /* R600+ */
 #define R600_RING_TYPE_UVD_INDEX        5
 
+/* number of hw syncs before falling back on blocking */
+#define RADEON_NUM_SYNCS                        4
+
 /* hardcode those limit for now */
 #define RADEON_VA_IB_OFFSET                     (1 << 20)
 #define RADEON_VA_RESERVED_SIZE                 (8 << 20)
@@ -554,7 +557,6 @@ int radeon_mode_dumb_mmap(struct drm_file *filp,
 /*
  * Semaphores.
  */
-/* everything here is constant */
 struct radeon_semaphore {
         struct radeon_sa_bo             *sa_bo;
         signed                          waiters;
diff --git a/drivers/gpu/drm/radeon/radeon_ring.c b/drivers/gpu/drm/radeon/radeon_ring.c
index 1b783f0e6d3a..15e44a7281ab 100644
--- a/drivers/gpu/drm/radeon/radeon_ring.c
+++ b/drivers/gpu/drm/radeon/radeon_ring.c
@@ -139,7 +139,7 @@ int radeon_ib_schedule(struct radeon_device *rdev, struct radeon_ib *ib,
         }
 
         /* 64 dwords should be enough for fence too */
-        r = radeon_ring_lock(rdev, ring, 64 + RADEON_NUM_RINGS * 8);
+        r = radeon_ring_lock(rdev, ring, 64 + RADEON_NUM_SYNCS * 8);
         if (r) {
                 dev_err(rdev->dev, "scheduling IB failed (%d).\n", r);
                 return r;
diff --git a/drivers/gpu/drm/radeon/radeon_semaphore.c b/drivers/gpu/drm/radeon/radeon_semaphore.c
index 2b42aa1914f2..9006b32d5eed 100644
--- a/drivers/gpu/drm/radeon/radeon_semaphore.c
+++ b/drivers/gpu/drm/radeon/radeon_semaphore.c
@@ -34,14 +34,15 @@
 int radeon_semaphore_create(struct radeon_device *rdev,
                             struct radeon_semaphore **semaphore)
 {
+        uint32_t *cpu_addr;
         int i, r;
 
         *semaphore = kmalloc(sizeof(struct radeon_semaphore), GFP_KERNEL);
         if (*semaphore == NULL) {
                 return -ENOMEM;
         }
-        r = radeon_sa_bo_new(rdev, &rdev->ring_tmp_bo,
-                             &(*semaphore)->sa_bo, 8, 8, true);
+        r = radeon_sa_bo_new(rdev, &rdev->ring_tmp_bo, &(*semaphore)->sa_bo,
+                             8 * RADEON_NUM_SYNCS, 8, true);
         if (r) {
                 kfree(*semaphore);
                 *semaphore = NULL;
@@ -49,7 +50,10 @@ int radeon_semaphore_create(struct radeon_device *rdev,
         }
         (*semaphore)->waiters = 0;
         (*semaphore)->gpu_addr = radeon_sa_bo_gpu_addr((*semaphore)->sa_bo);
-        *((uint64_t*)radeon_sa_bo_cpu_addr((*semaphore)->sa_bo)) = 0;
+
+        cpu_addr = radeon_sa_bo_cpu_addr((*semaphore)->sa_bo);
+        for (i = 0; i < RADEON_NUM_SYNCS; ++i)
+                cpu_addr[i] = 0;
 
         for (i = 0; i < RADEON_NUM_RINGS; ++i)
                 (*semaphore)->sync_to[i] = NULL;
@@ -125,6 +129,7 @@ int radeon_semaphore_sync_rings(struct radeon_device *rdev,
                                 struct radeon_semaphore *semaphore,
                                 int ring)
 {
+        unsigned count = 0;
         int i, r;
 
         for (i = 0; i < RADEON_NUM_RINGS; ++i) {
@@ -140,6 +145,12 @@ int radeon_semaphore_sync_rings(struct radeon_device *rdev,
                         return -EINVAL;
                 }
 
+                if (++count > RADEON_NUM_SYNCS) {
+                        /* not enough room, wait manually */
+                        radeon_fence_wait_locked(fence);
+                        continue;
+                }
+
                 /* allocate enough space for sync command */
                 r = radeon_ring_alloc(rdev, &rdev->ring[i], 16);
                 if (r) {
@@ -164,6 +175,8 @@ int radeon_semaphore_sync_rings(struct radeon_device *rdev,
 
                 radeon_ring_commit(rdev, &rdev->ring[i]);
                 radeon_fence_note_sync(fence, ring);
+
+                semaphore->gpu_addr += 8;
         }
 
         return 0;