From: Alex Sierra <alex.sierra@amd.com>
Date: Tue, 15 Aug 2023 20:42:52 +0000 (-0500)
Subject: drm/amdkfd: retry after EBUSY is returned from hmm_ranges_get_pages
X-Git-Tag: v6.5.12~321
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=96dc6e62eb99a8e8497cee6c599cebf05c16dc4b;p=thirdparty%2Fkernel%2Fstable.git

drm/amdkfd: retry after EBUSY is returned from hmm_ranges_get_pages

[ Upstream commit ebac9414a56a5f7c336db5f5c7cc34713b649407 ]

if hmm_range_get_pages returns EBUSY error during
svm_range_validate_and_map, within the context of a page fault
interrupt. This should retry through svm_range_restore_pages
callback. Therefore we treat this as EAGAIN error instead, and defer
it to restore pages fallback.

Signed-off-by: Alex Sierra <alex.sierra@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Stable-dep-of: eb3c357bcb28 ("drm/amdkfd: Handle errors from svm validate and map")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index a9b57c66cb7d7..4c1b72194a6f8 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -1651,6 +1651,8 @@ static int svm_range_validate_and_map(struct mm_struct *mm,
 		WRITE_ONCE(p->svms.faulting_task, NULL);
 		if (r) {
 			pr_debug("failed %d to get svm range pages\n", r);
+			if (r == -EBUSY)
+				r = -EAGAIN;
 			goto unreserve_out;
 		}