drm/amdkfd: Use non-atomic bitmap functions when possible

All uses of the 'kfd->gtt_sa_bitmap' bitmap are protected with the
'kfd->gtt_sa_lock' mutex.

So:
   - prefer the non-atomic '__set_bit()' function
   - use the non-atomic 'bitmap_[set|clear]()' functions instead of
     equivalent 'for' loops. These functions can work on several bits at a
     time
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdkfd/kfd_device.c

@@ -967,7 +967,7 @@ int kfd_gtt_sa_allocate(struct kfd_dev *kfd, unsigned int size,
 	/* If we need only one chunk, mark it as allocated and get out */
 	if (size <= kfd->gtt_sa_chunk_size) {
 		pr_debug("Single bit\n");
-		set_bit(found, kfd->gtt_sa_bitmap);
+		__set_bit(found, kfd->gtt_sa_bitmap);
 		goto kfd_gtt_out;
 	}
 
@@ -1005,10 +1005,8 @@ int kfd_gtt_sa_allocate(struct kfd_dev *kfd, unsigned int size,
 		(*mem_obj)->range_start, (*mem_obj)->range_end);
 
 	/* Mark the chunks as allocated */
-	for (found = (*mem_obj)->range_start;
-		found <= (*mem_obj)->range_end;
-		found++)
-		set_bit(found, kfd->gtt_sa_bitmap);
+	bitmap_set(kfd->gtt_sa_bitmap, (*mem_obj)->range_start,
+		   (*mem_obj)->range_end - (*mem_obj)->range_start + 1);
 
 kfd_gtt_out:
 	mutex_unlock(&kfd->gtt_sa_lock);
@@ -1023,8 +1021,6 @@ int kfd_gtt_sa_allocate(struct kfd_dev *kfd, unsigned int size,
 
 int kfd_gtt_sa_free(struct kfd_dev *kfd, struct kfd_mem_obj *mem_obj)
 {
-	unsigned int bit;
-
 	/* Act like kfree when trying to free a NULL object */
 	if (!mem_obj)
 		return 0;
@@ -1035,10 +1031,8 @@ int kfd_gtt_sa_free(struct kfd_dev *kfd, struct kfd_mem_obj *mem_obj)
 	mutex_lock(&kfd->gtt_sa_lock);
 
 	/* Mark the chunks as free */
-	for (bit = mem_obj->range_start;
-		bit <= mem_obj->range_end;
-		bit++)
-		clear_bit(bit, kfd->gtt_sa_bitmap);
+	bitmap_clear(kfd->gtt_sa_bitmap, mem_obj->range_start,
+		     mem_obj->range_end - mem_obj->range_start + 1);
 
 	mutex_unlock(&kfd->gtt_sa_lock);