drm/xe: Wait for migration job before unmapping pages

JIRA: https://issues.redhat.com/browse/RHEL-53571
Upstream Status: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git (v6.12.9)

commit c8f05dc
Author:     Nirmoy Das <nirmoy.das@intel.com>
AuthorDate: Fri Dec 13 13:24:15 2024 +0100
Commit:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CommitDate: Thu Jan  9 13:33:49 2025 +0100

    commit 5e0a67f upstream.

    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: 75521e8 ("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>
    (cherry picked from commit cda0641)
    Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>

Author: Jocelyn Falempe

drivers/gpu/drm/xe/xe_bo.c

@@ -846,8 +846,16 @@ 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;
 }