From: Nirmoy Das <nirmoy.das@intel.com>
Date: Fri, 13 Dec 2024 12:24:15 +0000 (+0100)
Subject: drm/xe: Wait for migration job before unmapping pages
X-Git-Tag: v6.14-rc1~174^2~9^2~17
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=cda06412c06893a6f07a2fbf89d42a0972ec9e8e;p=thirdparty%2Flinux.git

drm/xe: Wait for migration job before unmapping pages

Fix a potential GPU page fault during tt -> system moves by waiting for
migration jobs to complete before unmapping SG. This ensures that IOMMU
mappings are not prematurely torn down while a migration job is still in
progress.

v2: Use intr=false(Matt A)
v3: Update commit message(Matt A)
v4: s/DMA_RESV_USAGE_BOOKKEEP/DMA_RESV_USAGE_KERNEL(Thomas)

Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/3466
Fixes: 75521e8b56e8 ("drm/xe: Perform dma_map when moving system buffer objects to TT")
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: stable@vger.kernel.org # v6.11+
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241213122415.3880017-2-nirmoy.das@intel.com
Signed-off-by: Nirmoy Das <nirmoy.das@intel.com>
---

diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c
index 06931df876aba..e6c896ad5602a 100644
--- a/drivers/gpu/drm/xe/xe_bo.c
+++ b/drivers/gpu/drm/xe/xe_bo.c
@@ -857,8 +857,16 @@ static int xe_bo_move(struct ttm_buffer_object *ttm_bo, bool evict,
 
 out:
 	if ((!ttm_bo->resource || ttm_bo->resource->mem_type == XE_PL_SYSTEM) &&
-	    ttm_bo->ttm)
+	    ttm_bo->ttm) {
+		long timeout = dma_resv_wait_timeout(ttm_bo->base.resv,
+						     DMA_RESV_USAGE_KERNEL,
+						     false,
+						     MAX_SCHEDULE_TIMEOUT);
+		if (timeout < 0)
+			ret = timeout;
+
 		xe_tt_unmap_sg(ttm_bo->ttm);
+	}
 
 	return ret;
 }