drm/amdkfd: Allocate gtt_sa_bitmap in long units

gtt_sa_bitmap is accessed by bitmap functions, which operate on longs.
Therefore the array should be allocated in long units. Also round up
in case the number of bits is not a multiple of BITS_PER_LONG.

Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>

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

@@ -395,7 +395,7 @@ void kgd2kfd_interrupt(struct kfd_dev *kfd, const void *ih_ring_entry)
 static int kfd_gtt_sa_init(struct kfd_dev *kfd, unsigned int buf_size,
 				unsigned int chunk_size)
 {
-	unsigned int num_of_bits;
+	unsigned int num_of_longs;
 
 	BUG_ON(buf_size < chunk_size);
 	BUG_ON(buf_size == 0);
@@ -404,10 +404,10 @@ static int kfd_gtt_sa_init(struct kfd_dev *kfd, unsigned int buf_size,
 	kfd->gtt_sa_chunk_size = chunk_size;
 	kfd->gtt_sa_num_of_chunks = buf_size / chunk_size;
 
-	num_of_bits = kfd->gtt_sa_num_of_chunks / BITS_PER_BYTE;
-	BUG_ON(num_of_bits == 0);
+	num_of_longs = (kfd->gtt_sa_num_of_chunks + BITS_PER_LONG - 1) /
+		BITS_PER_LONG;
 
-	kfd->gtt_sa_bitmap = kzalloc(num_of_bits, GFP_KERNEL);
+	kfd->gtt_sa_bitmap = kcalloc(num_of_longs, sizeof(long), GFP_KERNEL);
 
 	if (!kfd->gtt_sa_bitmap)
 		return -ENOMEM;