iommu/amd: Fix sleeping in atomic context

Commit cf70873 ("iommu/amd: Refactor GCR3 table helper functions")
changed GFP flag we use for GCR3 table. Original plan was to move GCR3
table allocation outside spinlock. But this requires complete rework of
attach device path. Hence we didn't do it as part of SVA series. For now
revert the GFP flag to ATOMIC (same as original code).

Fixes: cf70873 ("iommu/amd: Refactor GCR3 table helper functions")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Link: https://lore.kernel.org/r/20240307052738.116035-1-vasant.hegde@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

Author: hegdevasant

drivers/iommu/amd/iommu.c

@@ -1793,7 +1793,7 @@ static int setup_gcr3_table(struct gcr3_tbl_info *gcr3_info,
 	/* Allocate per device domain ID */
 	gcr3_info->domid = domain_id_alloc();
 
-	gcr3_info->gcr3_tbl = alloc_pgtable_page(nid, GFP_KERNEL);
+	gcr3_info->gcr3_tbl = alloc_pgtable_page(nid, GFP_ATOMIC);
 	if (gcr3_info->gcr3_tbl == NULL) {
 		domain_id_free(gcr3_info->domid);
 		return -ENOMEM;