From 8221d21b0664d79a4319bad526f4f727d3b15981 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Wed, 3 Jul 2019 10:17:13 +0100
Subject: drm/i915/selftests: Lock the drm_mm while modifying
Git-commit: 8221d21b0664d79a4319bad526f4f727d3b15981
Patch-mainline: v5.4-rc1
References: bsc#1152489

Remember to lock the drm_mm as we modify it, lest it be modified in the
background by retire/free workers!

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190703091726.11690-2-chris@chris-wilson.co.uk
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c
index a1f0b235f56b..9b05bef15023 100644
--- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c
+++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c
@@ -414,7 +414,9 @@ static int igt_mmap_offset_exhaustion(void *arg)
 	drm_mm_for_each_hole(hole, mm, hole_start, hole_end) {
 		resv.start = hole_start;
 		resv.size = hole_end - hole_start - 1; /* PAGE_SIZE units */
+		mutex_lock(&i915->drm.struct_mutex);
 		err = drm_mm_reserve_node(mm, &resv);
+		mutex_unlock(&i915->drm.struct_mutex);
 		if (err) {
 			pr_err("Failed to trim VMA manager, err=%d\n", err);
 			goto out_park;
@@ -478,7 +480,9 @@ static int igt_mmap_offset_exhaustion(void *arg)
 	}
 
 out:
+	mutex_lock(&i915->drm.struct_mutex);
 	drm_mm_remove_node(&resv);
+	mutex_unlock(&i915->drm.struct_mutex);
 out_park:
 	restore_retire_worker(i915);
 	return err;
-- 
2.28.0