drm/tests: shmem: Hold reservation lock around vmap/vunmap

Acquire and release the GEM object's reservation lock around vmap and
vunmap operations. The tests use vmap_locked, which led to errors such
as show below.

[  122.292030] WARNING: CPU: 3 PID: 1413 at drivers/gpu/drm/drm_gem_shmem_helper.c:390 drm_gem_shmem_vmap_locked+0x3a3/0x6f0

[  122.468066] WARNING: CPU: 3 PID: 1413 at drivers/gpu/drm/drm_gem_shmem_helper.c:293 drm_gem_shmem_pin_locked+0x1fe/0x350

[  122.563504] WARNING: CPU: 3 PID: 1413 at drivers/gpu/drm/drm_gem_shmem_helper.c:234 drm_gem_shmem_get_pages_locked+0x23c/0x370

[  122.662248] WARNING: CPU: 2 PID: 1413 at drivers/gpu/drm/drm_gem_shmem_helper.c:452 drm_gem_shmem_vunmap_locked+0x101/0x330

Only export the new vmap/vunmap helpers for Kunit tests. These are
not interfaces for regular drivers.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 954907f7147d ("drm/shmem-helper: Refactor locked/unlocked functions")
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v6.16+
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://patch.msgid.link/20251212160317.287409-4-tzimmermann@suse.de

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index fbd1164174b04e7ca1ffd639027facfafeeceffa..de4de594c78b3afa8b083ef8f6df71d150a92fab 100644 (file)
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -15,6 +15,8 @@
 #include <asm/set_memory.h>
 #endif
 
+#include <kunit/visibility.h>
+
 #include <drm/drm.h>
 #include <drm/drm_device.h>
 #include <drm/drm_drv.h>
@@ -901,6 +903,37 @@ fail_detach:
 }
 EXPORT_SYMBOL_GPL(drm_gem_shmem_prime_import_no_map);
 
+/*
+ * Kunit helpers
+ */
+
+#if IS_ENABLED(CONFIG_KUNIT)
+int drm_gem_shmem_vmap(struct drm_gem_shmem_object *shmem, struct iosys_map *map)
+{
+       struct drm_gem_object *obj = &shmem->base;
+       int ret;
+
+       ret = dma_resv_lock_interruptible(obj->resv, NULL);
+       if (ret)
+               return ret;
+       ret = drm_gem_shmem_vmap_locked(shmem, map);
+       dma_resv_unlock(obj->resv);
+
+       return ret;
+}
+EXPORT_SYMBOL_IF_KUNIT(drm_gem_shmem_vmap);
+
+void drm_gem_shmem_vunmap(struct drm_gem_shmem_object *shmem, struct iosys_map *map)
+{
+       struct drm_gem_object *obj = &shmem->base;
+
+       dma_resv_lock_interruptible(obj->resv, NULL);
+       drm_gem_shmem_vunmap_locked(shmem, map);
+       dma_resv_unlock(obj->resv);
+}
+EXPORT_SYMBOL_IF_KUNIT(drm_gem_shmem_vunmap);
+#endif
+
 MODULE_DESCRIPTION("DRM SHMEM memory-management helpers");
 MODULE_IMPORT_NS("DMA_BUF");
 MODULE_LICENSE("GPL v2");

diff --git a/drivers/gpu/drm/tests/drm_gem_shmem_test.c b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
index 1d50bab51ef3f0bf99a8a955c617bdf219115cbd..3e7c6f20fbccaf7fd6ec52cd4abbc3f1962809b9 100644 (file)
--- a/drivers/gpu/drm/tests/drm_gem_shmem_test.c
+++ b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
@@ -19,6 +19,8 @@
 #include <drm/drm_gem_shmem_helper.h>
 #include <drm/drm_kunit_helpers.h>
 
+MODULE_IMPORT_NS("EXPORTED_FOR_KUNIT_TESTING");
+
 #define TEST_SIZE              SZ_1M
 #define TEST_BYTE              0xae
 
@@ -176,7 +178,7 @@ static void drm_gem_shmem_test_vmap(struct kunit *test)
        ret = kunit_add_action_or_reset(test, drm_gem_shmem_free_wrapper, shmem);
        KUNIT_ASSERT_EQ(test, ret, 0);
 
-       ret = drm_gem_shmem_vmap_locked(shmem, &map);
+       ret = drm_gem_shmem_vmap(shmem, &map);
        KUNIT_ASSERT_EQ(test, ret, 0);
        KUNIT_ASSERT_NOT_NULL(test, shmem->vaddr);
        KUNIT_ASSERT_FALSE(test, iosys_map_is_null(&map));
@@ -186,7 +188,7 @@ static void drm_gem_shmem_test_vmap(struct kunit *test)
        for (i = 0; i < TEST_SIZE; i++)
                KUNIT_EXPECT_EQ(test, iosys_map_rd(&map, i, u8), TEST_BYTE);
 
-       drm_gem_shmem_vunmap_locked(shmem, &map);
+       drm_gem_shmem_vunmap(shmem, &map);
        KUNIT_EXPECT_NULL(test, shmem->vaddr);
        KUNIT_EXPECT_EQ(test, refcount_read(&shmem->vmap_use_count), 0);
 }

diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h
index 6b6478f5ca2473df8d5b6fa20ab150d6a6b7087b..a80b5bda92714b2c30728a9fe251c502f1baba38 100644 (file)
--- a/include/drm/drm_gem_shmem_helper.h
+++ b/include/drm/drm_gem_shmem_helper.h
@@ -300,4 +300,13 @@ struct drm_gem_object *drm_gem_shmem_prime_import_no_map(struct drm_device *dev,
        .gem_prime_import       = drm_gem_shmem_prime_import_no_map, \
        .dumb_create            = drm_gem_shmem_dumb_create
 
+/*
+ * Kunit helpers
+ */
+
+#if IS_ENABLED(CONFIG_KUNIT)
+int drm_gem_shmem_vmap(struct drm_gem_shmem_object *shmem, struct iosys_map *map);
+void drm_gem_shmem_vunmap(struct drm_gem_shmem_object *shmem, struct iosys_map *map);
+#endif
+
 #endif /* __DRM_GEM_SHMEM_HELPER_H__ */