drm/ttm: Have the TTM code return -ERESTARTSYS instead of -ERESTART.

Return -ERESTARTSYS instead of -ERESTART when interrupted by a signal.
The -ERESTARTSYS is converted to an -EINTR by the kernel signal layer
before returned to user-space.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/ttm/ttm_bo.c

@@ -125,7 +125,7 @@ int ttm_bo_wait_unreserved(struct ttm_buffer_object *bo, bool interruptible)
 		ret = wait_event_interruptible(bo->event_queue,
 					       atomic_read(&bo->reserved) == 0);
 		if (unlikely(ret != 0))
-			return -ERESTART;
+			return ret;
 	} else {
 		wait_event(bo->event_queue, atomic_read(&bo->reserved) == 0);
 	}
@@ -571,7 +571,7 @@ static int ttm_bo_evict(struct ttm_buffer_object *bo, bool interruptible,
 	spin_unlock(&bo->lock);
 
 	if (unlikely(ret != 0)) {
-		if (ret != -ERESTART) {
+		if (ret != -ERESTARTSYS) {
 			printk(KERN_ERR TTM_PFX
 			       "Failed to expire sync object before "
 			       "buffer eviction.\n");
@@ -588,7 +588,7 @@ static int ttm_bo_evict(struct ttm_buffer_object *bo, bool interruptible,
 	ret = ttm_bo_mem_space(bo, &placement, &evict_mem, interruptible,
 				no_wait);
 	if (ret) {
-		if (ret != -ERESTART)
+		if (ret != -ERESTARTSYS)
 			printk(KERN_ERR TTM_PFX
 			       "Failed to find memory space for "
 			       "buffer 0x%p eviction.\n", bo);
@@ -598,7 +598,7 @@ static int ttm_bo_evict(struct ttm_buffer_object *bo, bool interruptible,
 	ret = ttm_bo_handle_move_mem(bo, &evict_mem, true, interruptible,
 				     no_wait);
 	if (ret) {
-		if (ret != -ERESTART)
+		if (ret != -ERESTARTSYS)
 			printk(KERN_ERR TTM_PFX "Buffer eviction failed\n");
 		spin_lock(&glob->lru_lock);
 		if (evict_mem.mm_node) {
@@ -795,7 +795,7 @@ int ttm_bo_mem_space(struct ttm_buffer_object *bo,
 	uint32_t cur_flags = 0;
 	bool type_found = false;
 	bool type_ok = false;
-	bool has_eagain = false;
+	bool has_erestartsys = false;
 	struct drm_mm_node *node = NULL;
 	int i, ret;
 
@@ -882,28 +882,21 @@ int ttm_bo_mem_space(struct ttm_buffer_object *bo,
 			mem->mm_node->private = bo;
 			return 0;
 		}
-		if (ret == -ERESTART)
-			has_eagain = true;
+		if (ret == -ERESTARTSYS)
+			has_erestartsys = true;
 	}
-	ret = (has_eagain) ? -ERESTART : -ENOMEM;
+	ret = (has_erestartsys) ? -ERESTARTSYS : -ENOMEM;
 	return ret;
 }
 EXPORT_SYMBOL(ttm_bo_mem_space);
 
 int ttm_bo_wait_cpu(struct ttm_buffer_object *bo, bool no_wait)
 {
-	int ret = 0;
-
 	if ((atomic_read(&bo->cpu_writers) > 0) && no_wait)
 		return -EBUSY;
 
-	ret = wait_event_interruptible(bo->event_queue,
-				       atomic_read(&bo->cpu_writers) == 0);
-
-	if (ret == -ERESTARTSYS)
-		ret = -ERESTART;
-
-	return ret;
+	return wait_event_interruptible(bo->event_queue,
+					atomic_read(&bo->cpu_writers) == 0);
 }
 
 int ttm_bo_move_buffer(struct ttm_buffer_object *bo,
@@ -1673,7 +1666,7 @@ int ttm_bo_block_reservation(struct ttm_buffer_object *bo, bool interruptible,
 			ret = wait_event_interruptible
 			    (bo->event_queue, atomic_read(&bo->reserved) == 0);
 			if (unlikely(ret != 0))
-				return -ERESTART;
+				return ret;
 		} else {
 			wait_event(bo->event_queue,
 				   atomic_read(&bo->reserved) == 0);

drivers/gpu/drm/ttm/ttm_bo_vm.c

@@ -114,7 +114,7 @@ static int ttm_bo_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 		ret = ttm_bo_wait(bo, false, true, false);
 		spin_unlock(&bo->lock);
 		if (unlikely(ret != 0)) {
-			retval = (ret != -ERESTART) ?
+			retval = (ret != -ERESTARTSYS) ?
 			    VM_FAULT_SIGBUS : VM_FAULT_NOPAGE;
 			goto out_unlock;
 		}
@@ -349,9 +349,6 @@ ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
 	switch (ret) {
 	case 0:
 		break;
-	case -ERESTART:
-		ret = -EINTR;
-		goto out_unref;
 	case -EBUSY:
 		ret = -EAGAIN;
 		goto out_unref;
@@ -421,8 +418,6 @@ ssize_t ttm_bo_fbdev_io(struct ttm_buffer_object *bo, const char __user *wbuf,
 	switch (ret) {
 	case 0:
 		break;
-	case -ERESTART:
-		return -EINTR;
 	case -EBUSY:
 		return -EAGAIN;
 	default:

include/drm/ttm/ttm_bo_api.h

@@ -303,7 +303,7 @@ ttm_bo_reference(struct ttm_buffer_object *bo)
  * Note: It might be necessary to block validations before the
  * wait by reserving the buffer.
  * Returns -EBUSY if no_wait is true and the buffer is busy.
- * Returns -ERESTART if interrupted by a signal.
+ * Returns -ERESTARTSYS if interrupted by a signal.
  */
 extern int ttm_bo_wait(struct ttm_buffer_object *bo, bool lazy,
 		       bool interruptible, bool no_wait);
@@ -321,7 +321,7 @@ extern int ttm_bo_wait(struct ttm_buffer_object *bo, bool lazy,
  * -EINVAL on invalid proposed placement.
  * -ENOMEM on out-of-memory condition.
  * -EBUSY if no_wait is true and buffer busy.
- * -ERESTART if interrupted by a signal.
+ * -ERESTARTSYS if interrupted by a signal.
  */
 extern int ttm_buffer_object_validate(struct ttm_buffer_object *bo,
 					struct ttm_placement *placement,
@@ -347,7 +347,7 @@ extern void ttm_bo_unref(struct ttm_buffer_object **bo);
  * waiting for buffer idle. This lock is recursive.
  * Returns
  * -EBUSY if the buffer is busy and no_wait is true.
- * -ERESTART if interrupted by a signal.
+ * -ERESTARTSYS if interrupted by a signal.
  */
 
 extern int
@@ -390,7 +390,7 @@ extern void ttm_bo_synccpu_write_release(struct ttm_buffer_object *bo);
  * Returns
  * -ENOMEM: Out of memory.
  * -EINVAL: Invalid placement flags.
- * -ERESTART: Interrupted by signal while sleeping waiting for resources.
+ * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
  */
 
 extern int ttm_buffer_object_init(struct ttm_bo_device *bdev,
@@ -430,7 +430,7 @@ extern int ttm_buffer_object_init(struct ttm_bo_device *bdev,
  * Returns
  * -ENOMEM: Out of memory.
  * -EINVAL: Invalid placement flags.
- * -ERESTART: Interrupted by signal while waiting for resources.
+ * -ERESTARTSYS: Interrupted by signal while waiting for resources.
  */
 
 extern int ttm_buffer_object_create(struct ttm_bo_device *bdev,
@@ -521,7 +521,7 @@ extern int ttm_bo_clean_mm(struct ttm_bo_device *bdev, unsigned mem_type);
  *
  * Returns:
  * -EINVAL: Invalid or uninitialized memory type.
- * -ERESTART: The call was interrupted by a signal while waiting to
+ * -ERESTARTSYS: The call was interrupted by a signal while waiting to
  * evict a buffer.
  */
 
@@ -624,7 +624,7 @@ extern int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
  * be called from the fops::read and fops::write method.
  * Returns:
  * See man (2) write, man(2) read. In particular,
- * the function may return -EINTR if
+ * the function may return -ERESTARTSYS if
  * interrupted by a signal.
  */
 

include/drm/ttm/ttm_bo_driver.h

@@ -638,7 +638,7 @@ extern bool ttm_mem_reg_is_pci(struct ttm_bo_device *bdev,
  * -EBUSY: No space available (only if no_wait == 1).
  * -ENOMEM: Could not allocate memory for the buffer object, either due to
  * fragmentation or concurrent allocators.
- * -ERESTART: An interruptible sleep was interrupted by a signal.
+ * -ERESTARTSYS: An interruptible sleep was interrupted by a signal.
  */
 extern int ttm_bo_mem_space(struct ttm_buffer_object *bo,
 				struct ttm_placement *placement,
@@ -653,7 +653,7 @@ extern int ttm_bo_mem_space(struct ttm_buffer_object *bo,
  * Wait until a buffer object is no longer sync'ed for CPU access.
  * Returns:
  * -EBUSY: Buffer object was sync'ed for CPU access. (only if no_wait == 1).
- * -ERESTART: An interruptible sleep was interrupted by a signal.
+ * -ERESTARTSYS: An interruptible sleep was interrupted by a signal.
  */
 
 extern int ttm_bo_wait_cpu(struct ttm_buffer_object *bo, bool no_wait);
@@ -757,7 +757,7 @@ extern void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo);
  * -EAGAIN: The reservation may cause a deadlock.
  * Release all buffer reservations, wait for @bo to become unreserved and
  * try again. (only if use_sequence == 1).
- * -ERESTART: A wait for the buffer to become unreserved was interrupted by
+ * -ERESTARTSYS: A wait for the buffer to become unreserved was interrupted by
  * a signal. Release all buffer reservations and return to user-space.
  */
 extern int ttm_bo_reserve(struct ttm_buffer_object *bo,
@@ -798,7 +798,7 @@ extern int ttm_bo_wait_unreserved(struct ttm_buffer_object *bo,
  *
  * Returns:
  * -EBUSY: If no_wait == 1 and the buffer is already reserved.
- * -ERESTART: If interruptible == 1 and the process received a signal
+ * -ERESTARTSYS: If interruptible == 1 and the process received a signal
  * while sleeping.
  */
 extern int ttm_bo_block_reservation(struct ttm_buffer_object *bo,