amdkfd: use sizeof(long) granularity for the pasid bitmask

All the bit operations (such as find_first_zero_bit()) read sizeof(long) bytes
at a time. If we allocated less than sizeof(long) bytes for the bitmask we
would be accessing invalid memory when working with the bitmask.

Change the allocator to allocate sizeof(long) multiples for the bitmask.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Oded Gabbay <oded.gabbay@amd.com>

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

@@ -32,8 +32,7 @@ int kfd_pasid_init(void)
 {
 	pasid_limit = max_num_of_processes;
 
-	pasid_bitmap = kzalloc(DIV_ROUND_UP(pasid_limit, BITS_PER_BYTE),
-				GFP_KERNEL);
+	pasid_bitmap = kzalloc(BITS_TO_LONGS(pasid_limit), GFP_KERNEL);
 	if (!pasid_bitmap)
 		return -ENOMEM;