drm/ttm: kill fence_lock

No users are left, kill it off! :D
Conversion to the reservation api is next on the list, after
that the functionality can be restored with rcu.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>

4 files changed, 18 insertions, 67 deletions

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 4f1bc948bda0..195386f16ca4 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -415,24 +415,20 @@ static void ttm_bo_cleanup_refs_or_queue(struct ttm_buffer_object *bo)
         spin_lock(&glob->lru_lock);
         ret = __ttm_bo_reserve(bo, false, true, false, NULL);
 
-        spin_lock(&bdev->fence_lock);
-        (void) ttm_bo_wait(bo, false, false, true);
-        if (!ret && !bo->sync_obj) {
-                spin_unlock(&bdev->fence_lock);
-                put_count = ttm_bo_del_from_lru(bo);
+        if (!ret) {
+                (void) ttm_bo_wait(bo, false, false, true);
 
-                spin_unlock(&glob->lru_lock);
-                ttm_bo_cleanup_memtype_use(bo);
+                if (!bo->sync_obj) {
+                        put_count = ttm_bo_del_from_lru(bo);
 
-                ttm_bo_list_ref_sub(bo, put_count, true);
+                        spin_unlock(&glob->lru_lock);
+                        ttm_bo_cleanup_memtype_use(bo);
 
-                return;
-        }
-        if (bo->sync_obj)
-                sync_obj = driver->sync_obj_ref(bo->sync_obj);
-        spin_unlock(&bdev->fence_lock);
+                        ttm_bo_list_ref_sub(bo, put_count, true);
 
-        if (!ret) {
+                        return;
+                }
+                sync_obj = driver->sync_obj_ref(bo->sync_obj);
 
                 /*
                  * Make NO_EVICT bos immediately available to
@@ -481,7 +477,6 @@ static int ttm_bo_cleanup_refs_and_unlock(struct ttm_buffer_object *bo,
         int put_count;
         int ret;
 
-        spin_lock(&bdev->fence_lock);
         ret = ttm_bo_wait(bo, false, false, true);
 
         if (ret && !no_wait_gpu) {
@@ -493,7 +488,6 @@ static int ttm_bo_cleanup_refs_and_unlock(struct ttm_buffer_object *bo,
                  * no new sync objects can be attached.
                  */
                 sync_obj = driver->sync_obj_ref(bo->sync_obj);
-                spin_unlock(&bdev->fence_lock);
 
                 __ttm_bo_unreserve(bo);
                 spin_unlock(&glob->lru_lock);
@@ -523,11 +517,9 @@ static int ttm_bo_cleanup_refs_and_unlock(struct ttm_buffer_object *bo,
                  * remove sync_obj with ttm_bo_wait, the wait should be
                  * finished, and no new wait object should have been added.
                  */
-                spin_lock(&bdev->fence_lock);
                 ret = ttm_bo_wait(bo, false, false, true);
                 WARN_ON(ret);
         }
-        spin_unlock(&bdev->fence_lock);
 
         if (ret || unlikely(list_empty(&bo->ddestroy))) {
                 __ttm_bo_unreserve(bo);
@@ -665,9 +657,7 @@ static int ttm_bo_evict(struct ttm_buffer_object *bo, bool interruptible,
         struct ttm_placement placement;
         int ret = 0;
 
-        spin_lock(&bdev->fence_lock);
         ret = ttm_bo_wait(bo, false, interruptible, no_wait_gpu);
-        spin_unlock(&bdev->fence_lock);
 
         if (unlikely(ret != 0)) {
                 if (ret != -ERESTARTSYS) {
@@ -958,7 +948,6 @@ static int ttm_bo_move_buffer(struct ttm_buffer_object *bo,
 {
         int ret = 0;
         struct ttm_mem_reg mem;
-        struct ttm_bo_device *bdev = bo->bdev;
 
         lockdep_assert_held(&bo->resv->lock.base);
 
@@ -967,9 +956,7 @@ static int ttm_bo_move_buffer(struct ttm_buffer_object *bo,
          * Have the driver move function wait for idle when necessary,
          * instead of doing it here.
          */
-        spin_lock(&bdev->fence_lock);
         ret = ttm_bo_wait(bo, false, interruptible, no_wait_gpu);
-        spin_unlock(&bdev->fence_lock);
         if (ret)
                 return ret;
         mem.num_pages = bo->num_pages;
@@ -1459,7 +1446,6 @@ int ttm_bo_device_init(struct ttm_bo_device *bdev,
         bdev->glob = glob;
         bdev->need_dma32 = need_dma32;
         bdev->val_seq = 0;
-        spin_lock_init(&bdev->fence_lock);
         mutex_lock(&glob->device_list_mutex);
         list_add_tail(&bdev->device_list, &glob->device_list);
         mutex_unlock(&glob->device_list_mutex);
@@ -1517,7 +1503,6 @@ int ttm_bo_wait(struct ttm_buffer_object *bo,
                 bool lazy, bool interruptible, bool no_wait)
 {
         struct ttm_bo_driver *driver = bo->bdev->driver;
-        struct ttm_bo_device *bdev = bo->bdev;
         void *sync_obj;
         int ret = 0;
 
@@ -1526,53 +1511,33 @@ int ttm_bo_wait(struct ttm_buffer_object *bo,
         if (likely(bo->sync_obj == NULL))
                 return 0;
 
-        while (bo->sync_obj) {
-
+        if (bo->sync_obj) {
                 if (driver->sync_obj_signaled(bo->sync_obj)) {
-                        void *tmp_obj = bo->sync_obj;
-                        bo->sync_obj = NULL;
+                        driver->sync_obj_unref(&bo->sync_obj);
                         clear_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags);
-                        spin_unlock(&bdev->fence_lock);
-                        driver->sync_obj_unref(&tmp_obj);
-                        spin_lock(&bdev->fence_lock);
-                        continue;
+                        return 0;
                 }
 
                 if (no_wait)
                         return -EBUSY;
 
                 sync_obj = driver->sync_obj_ref(bo->sync_obj);
-                spin_unlock(&bdev->fence_lock);
                 ret = driver->sync_obj_wait(sync_obj,
                                             lazy, interruptible);
-                if (unlikely(ret != 0)) {
-                        driver->sync_obj_unref(&sync_obj);
-                        spin_lock(&bdev->fence_lock);
-                        return ret;
-                }
-                spin_lock(&bdev->fence_lock);
-                if (likely(bo->sync_obj == sync_obj)) {
-                        void *tmp_obj = bo->sync_obj;
-                        bo->sync_obj = NULL;
+
+                if (likely(ret == 0)) {
                         clear_bit(TTM_BO_PRIV_FLAG_MOVING,
                                   &bo->priv_flags);
-                        spin_unlock(&bdev->fence_lock);
-                        driver->sync_obj_unref(&sync_obj);
-                        driver->sync_obj_unref(&tmp_obj);
-                        spin_lock(&bdev->fence_lock);
-                } else {
-                        spin_unlock(&bdev->fence_lock);
-                        driver->sync_obj_unref(&sync_obj);
-                        spin_lock(&bdev->fence_lock);
+                        driver->sync_obj_unref(&bo->sync_obj);
                 }
+                driver->sync_obj_unref(&sync_obj);
         }
-        return 0;
+        return ret;
 }
 EXPORT_SYMBOL(ttm_bo_wait);
 
 int ttm_bo_synccpu_write_grab(struct ttm_buffer_object *bo, bool no_wait)
 {
-        struct ttm_bo_device *bdev = bo->bdev;
         int ret = 0;
 
         /*
@@ -1582,9 +1547,7 @@ int ttm_bo_synccpu_write_grab(struct ttm_buffer_object *bo, bool no_wait)
         ret = ttm_bo_reserve(bo, true, no_wait, false, NULL);
         if (unlikely(ret != 0))
                 return ret;
-        spin_lock(&bdev->fence_lock);
         ret = ttm_bo_wait(bo, false, true, no_wait);
-        spin_unlock(&bdev->fence_lock);
         if (likely(ret == 0))
                 atomic_inc(&bo->cpu_writers);
         ttm_bo_unreserve(bo);
@@ -1641,9 +1604,7 @@ static int ttm_bo_swapout(struct ttm_mem_shrink *shrink)
          * Wait for GPU, then move to system cached.
          */
 
-        spin_lock(&bo->bdev->fence_lock);
         ret = ttm_bo_wait(bo, false, false, false);
-        spin_unlock(&bo->bdev->fence_lock);
 
         if (unlikely(ret != 0))
                 goto out;
diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index 30e5d90cb7bc..495aebf0f9c3 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -466,12 +466,10 @@ static int ttm_buffer_object_transfer(struct ttm_buffer_object *bo,
         drm_vma_node_reset(&fbo->vma_node);
         atomic_set(&fbo->cpu_writers, 0);
 
-        spin_lock(&bdev->fence_lock);
         if (bo->sync_obj)
                 fbo->sync_obj = driver->sync_obj_ref(bo->sync_obj);
         else
                 fbo->sync_obj = NULL;
-        spin_unlock(&bdev->fence_lock);
         kref_init(&fbo->list_kref);
         kref_init(&fbo->kref);
         fbo->destroy = &ttm_transfered_destroy;
@@ -657,7 +655,6 @@ int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
         struct ttm_buffer_object *ghost_obj;
         void *tmp_obj = NULL;
 
-        spin_lock(&bdev->fence_lock);
         if (bo->sync_obj) {
                 tmp_obj = bo->sync_obj;
                 bo->sync_obj = NULL;
@@ -665,7 +662,6 @@ int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
         bo->sync_obj = driver->sync_obj_ref(sync_obj);
         if (evict) {
                 ret = ttm_bo_wait(bo, false, false, false);
-                spin_unlock(&bdev->fence_lock);
                 if (tmp_obj)
                         driver->sync_obj_unref(&tmp_obj);
                 if (ret)
@@ -688,7 +684,6 @@ int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
                  */
 
                 set_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags);
-                spin_unlock(&bdev->fence_lock);
                 if (tmp_obj)
                         driver->sync_obj_unref(&tmp_obj);
 
diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
index 0ce48e5a9cb4..d05437f219e9 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
@@ -45,10 +45,8 @@ static int ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
                                 struct vm_area_struct *vma,
                                 struct vm_fault *vmf)
 {
-        struct ttm_bo_device *bdev = bo->bdev;
         int ret = 0;
 
-        spin_lock(&bdev->fence_lock);
         if (likely(!test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)))
                 goto out_unlock;
 
@@ -82,7 +80,6 @@ static int ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
                         VM_FAULT_NOPAGE;
 
 out_unlock:
-        spin_unlock(&bdev->fence_lock);
         return ret;
 }
 
diff --git a/drivers/gpu/drm/ttm/ttm_execbuf_util.c b/drivers/gpu/drm/ttm/ttm_execbuf_util.c
index e8dac8758528..0fbbbbd67afc 100644
--- a/drivers/gpu/drm/ttm/ttm_execbuf_util.c
+++ b/drivers/gpu/drm/ttm/ttm_execbuf_util.c
@@ -217,7 +217,6 @@ void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket,
         glob = bo->glob;
 
         spin_lock(&glob->lru_lock);
-        spin_lock(&bdev->fence_lock);
 
         list_for_each_entry(entry, list, head) {
                 bo = entry->bo;
@@ -227,7 +226,6 @@ void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket,
                 __ttm_bo_unreserve(bo);
                 entry->reserved = false;
         }
-        spin_unlock(&bdev->fence_lock);
         spin_unlock(&glob->lru_lock);
         if (ticket)
                 ww_acquire_fini(ticket);