[PATCH 1/5] drm/tests: shmem: Swap names of export tests

[PATCH 1/5] drm/tests: shmem: Swap names of export tests

[Thomas Zimmermann]

GEM SHMEM has 2 helpers for exporting S/G tables. Swap the names of
the rsp. tests, so that each matches the helper it tests.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 93032ae634d4 ("drm/test: add a test suite for GEM objects backed by shmem")
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v6.8+
---
 drivers/gpu/drm/tests/drm_gem_shmem_test.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/tests/drm_gem_shmem_test.c b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
index 68f2c3162354..872881ec9c30 100644
--- a/drivers/gpu/drm/tests/drm_gem_shmem_test.c
+++ b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
@@ -194,7 +194,7 @@ static void drm_gem_shmem_test_vmap(struct kunit *test)
  * scatter/gather table large enough to accommodate the backing memory
  * is successfully exported.
  */
-static void drm_gem_shmem_test_get_pages_sgt(struct kunit *test)
+static void drm_gem_shmem_test_get_sg_table(struct kunit *test)
 {
 	struct drm_device *drm_dev = test->priv;
 	struct drm_gem_shmem_object *shmem;
@@ -236,7 +236,7 @@ static void drm_gem_shmem_test_get_pages_sgt(struct kunit *test)
  * backing pages are pinned and a scatter/gather table large enough to
  * accommodate the backing memory is successfully exported.
  */
-static void drm_gem_shmem_test_get_sg_table(struct kunit *test)
+static void drm_gem_shmem_test_get_pages_sgt(struct kunit *test)
 {
 	struct drm_device *drm_dev = test->priv;
 	struct drm_gem_shmem_object *shmem;
@@ -366,8 +366,8 @@ static struct kunit_case drm_gem_shmem_test_cases[] = {
 	KUNIT_CASE(drm_gem_shmem_test_obj_create_private),
 	KUNIT_CASE(drm_gem_shmem_test_pin_pages),
 	KUNIT_CASE(drm_gem_shmem_test_vmap),
-	KUNIT_CASE(drm_gem_shmem_test_get_pages_sgt),
 	KUNIT_CASE(drm_gem_shmem_test_get_sg_table),
+	KUNIT_CASE(drm_gem_shmem_test_get_pages_sgt),
 	KUNIT_CASE(drm_gem_shmem_test_madvise),
 	KUNIT_CASE(drm_gem_shmem_test_purge),
 	{}
-- 
2.52.0

Re: [PATCH 1/5] drm/tests: shmem: Swap names of export tests

[Boris Brezillon]

On Fri, 12 Dec 2025 17:00:32 +0100
Thomas Zimmermann <tzimmermann@suse.de> wrote:

> GEM SHMEM has 2 helpers for exporting S/G tables. Swap the names of
> the rsp. tests, so that each matches the helper it tests.
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> Fixes: 93032ae634d4 ("drm/test: add a test suite for GEM objects backed by shmem")
> Cc: dri-devel@lists.freedesktop.org
> Cc: <stable@vger.kernel.org> # v6.8+

Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>

> ---
>  drivers/gpu/drm/tests/drm_gem_shmem_test.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/tests/drm_gem_shmem_test.c b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
> index 68f2c3162354..872881ec9c30 100644
> --- a/drivers/gpu/drm/tests/drm_gem_shmem_test.c
> +++ b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
> @@ -194,7 +194,7 @@ static void drm_gem_shmem_test_vmap(struct kunit *test)
>   * scatter/gather table large enough to accommodate the backing memory
>   * is successfully exported.
>   */
> -static void drm_gem_shmem_test_get_pages_sgt(struct kunit *test)
> +static void drm_gem_shmem_test_get_sg_table(struct kunit *test)
>  {
>  	struct drm_device *drm_dev = test->priv;
>  	struct drm_gem_shmem_object *shmem;
> @@ -236,7 +236,7 @@ static void drm_gem_shmem_test_get_pages_sgt(struct kunit *test)
>   * backing pages are pinned and a scatter/gather table large enough to
>   * accommodate the backing memory is successfully exported.
>   */
> -static void drm_gem_shmem_test_get_sg_table(struct kunit *test)
> +static void drm_gem_shmem_test_get_pages_sgt(struct kunit *test)
>  {
>  	struct drm_device *drm_dev = test->priv;
>  	struct drm_gem_shmem_object *shmem;
> @@ -366,8 +366,8 @@ static struct kunit_case drm_gem_shmem_test_cases[] = {
>  	KUNIT_CASE(drm_gem_shmem_test_obj_create_private),
>  	KUNIT_CASE(drm_gem_shmem_test_pin_pages),
>  	KUNIT_CASE(drm_gem_shmem_test_vmap),
> -	KUNIT_CASE(drm_gem_shmem_test_get_pages_sgt),
>  	KUNIT_CASE(drm_gem_shmem_test_get_sg_table),
> +	KUNIT_CASE(drm_gem_shmem_test_get_pages_sgt),
>  	KUNIT_CASE(drm_gem_shmem_test_madvise),
>  	KUNIT_CASE(drm_gem_shmem_test_purge),
>  	{}

[PATCH 2/5] drm/tests: shmem: Add clean-up action to unpin pages

[Thomas Zimmermann]

Automatically unpin pages on cleanup. The test currently fails with
the error

[   58.246263] drm-kunit-mock-device drm_gem_shmem_test_get_sg_table.drm-kunit-mock-device: [drm] drm_WARN_ON(refcount_read(&shmem->pages_pin_count))

while cleaning up the GEM object. The pin count has to be zero at this
point.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: d586b535f144 ("drm/shmem-helper: Add and use pages_pin_count")
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v6.16+
---
 drivers/gpu/drm/tests/drm_gem_shmem_test.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/tests/drm_gem_shmem_test.c b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
index 872881ec9c30..1d50bab51ef3 100644
--- a/drivers/gpu/drm/tests/drm_gem_shmem_test.c
+++ b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
@@ -34,6 +34,9 @@ KUNIT_DEFINE_ACTION_WRAPPER(sg_free_table_wrapper, sg_free_table,
 KUNIT_DEFINE_ACTION_WRAPPER(drm_gem_shmem_free_wrapper, drm_gem_shmem_free,
 			    struct drm_gem_shmem_object *);
 
+KUNIT_DEFINE_ACTION_WRAPPER(drm_gem_shmem_unpin_wrapper, drm_gem_shmem_unpin,
+			    struct drm_gem_shmem_object *);
+
 /*
  * Test creating a shmem GEM object backed by shmem buffer. The test
  * case succeeds if the GEM object is successfully allocated with the
@@ -212,6 +215,9 @@ static void drm_gem_shmem_test_get_sg_table(struct kunit *test)
 	ret = drm_gem_shmem_pin(shmem);
 	KUNIT_ASSERT_EQ(test, ret, 0);
 
+	ret = kunit_add_action_or_reset(test, drm_gem_shmem_unpin_wrapper, shmem);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
 	sgt = drm_gem_shmem_get_sg_table(shmem);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, sgt);
 	KUNIT_EXPECT_NULL(test, shmem->sgt);
-- 
2.52.0

Re: [PATCH 2/5] drm/tests: shmem: Add clean-up action to unpin pages

[Boris Brezillon]

On Fri, 12 Dec 2025 17:00:33 +0100
Thomas Zimmermann <tzimmermann@suse.de> wrote:

> Automatically unpin pages on cleanup. The test currently fails with
> the error
> 
> [   58.246263] drm-kunit-mock-device drm_gem_shmem_test_get_sg_table.drm-kunit-mock-device: [drm] drm_WARN_ON(refcount_read(&shmem->pages_pin_count))
> 
> while cleaning up the GEM object. The pin count has to be zero at this
> point.
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> Fixes: d586b535f144 ("drm/shmem-helper: Add and use pages_pin_count")
> Cc: dri-devel@lists.freedesktop.org
> Cc: <stable@vger.kernel.org> # v6.16+

Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>

> ---
>  drivers/gpu/drm/tests/drm_gem_shmem_test.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/gpu/drm/tests/drm_gem_shmem_test.c b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
> index 872881ec9c30..1d50bab51ef3 100644
> --- a/drivers/gpu/drm/tests/drm_gem_shmem_test.c
> +++ b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
> @@ -34,6 +34,9 @@ KUNIT_DEFINE_ACTION_WRAPPER(sg_free_table_wrapper, sg_free_table,
>  KUNIT_DEFINE_ACTION_WRAPPER(drm_gem_shmem_free_wrapper, drm_gem_shmem_free,
>  			    struct drm_gem_shmem_object *);
>  
> +KUNIT_DEFINE_ACTION_WRAPPER(drm_gem_shmem_unpin_wrapper, drm_gem_shmem_unpin,
> +			    struct drm_gem_shmem_object *);
> +
>  /*
>   * Test creating a shmem GEM object backed by shmem buffer. The test
>   * case succeeds if the GEM object is successfully allocated with the
> @@ -212,6 +215,9 @@ static void drm_gem_shmem_test_get_sg_table(struct kunit *test)
>  	ret = drm_gem_shmem_pin(shmem);
>  	KUNIT_ASSERT_EQ(test, ret, 0);
>  
> +	ret = kunit_add_action_or_reset(test, drm_gem_shmem_unpin_wrapper, shmem);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
>  	sgt = drm_gem_shmem_get_sg_table(shmem);
>  	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, sgt);
>  	KUNIT_EXPECT_NULL(test, shmem->sgt);

[PATCH 3/5] drm/tests: shmem: Hold reservation lock around vmap/vunmap

[Thomas Zimmermann]

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+
---
 drivers/gpu/drm/drm_gem_shmem_helper.c     | 33 ++++++++++++++++++++++
 drivers/gpu/drm/tests/drm_gem_shmem_test.c |  6 ++--
 include/drm/drm_gem_shmem_helper.h         |  9 ++++++
 3 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index dc94a27710e5..06ef4e5adb7d 100644
--- 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>
@@ -893,6 +895,37 @@ struct drm_gem_object *drm_gem_shmem_prime_import_no_map(struct drm_device *dev,
 }
 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 1d50bab51ef3..3e7c6f20fbcc 100644
--- 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 589f7bfe7506..6924ee226655 100644
--- a/include/drm/drm_gem_shmem_helper.h
+++ b/include/drm/drm_gem_shmem_helper.h
@@ -303,4 +303,13 @@ 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__ */
-- 
2.52.0

Re: [PATCH 3/5] drm/tests: shmem: Hold reservation lock around vmap/vunmap

[Boris Brezillon]

On Fri, 12 Dec 2025 17:00:34 +0100
Thomas Zimmermann <tzimmermann@suse.de> wrote:

> 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>

> ---
>  drivers/gpu/drm/drm_gem_shmem_helper.c     | 33 ++++++++++++++++++++++
>  drivers/gpu/drm/tests/drm_gem_shmem_test.c |  6 ++--
>  include/drm/drm_gem_shmem_helper.h         |  9 ++++++
>  3 files changed, 46 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
> index dc94a27710e5..06ef4e5adb7d 100644
> --- 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>
> @@ -893,6 +895,37 @@ struct drm_gem_object *drm_gem_shmem_prime_import_no_map(struct drm_device *dev,
>  }
>  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 1d50bab51ef3..3e7c6f20fbcc 100644
> --- 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 589f7bfe7506..6924ee226655 100644
> --- a/include/drm/drm_gem_shmem_helper.h
> +++ b/include/drm/drm_gem_shmem_helper.h
> @@ -303,4 +303,13 @@ 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__ */

[PATCH 4/5] drm/tests: shmem: Hold reservation lock around madvise

[Thomas Zimmermann]

Acquire and release the GEM object's reservation lock around calls
to the object's madvide operation. The tests use
drm_gem_shmem_madvise_locked(), which led to errors such as show below.

[   58.339389] WARNING: CPU: 1 PID: 1352 at drivers/gpu/drm/drm_gem_shmem_helper.c:499 drm_gem_shmem_madvise_locked+0xde/0x140

Only export the new helper drm_gem_shmem_madvise() for Kunit tests.
This is not an interface 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+
---
 drivers/gpu/drm/drm_gem_shmem_helper.c     | 15 +++++++++++++++
 drivers/gpu/drm/tests/drm_gem_shmem_test.c |  8 ++++----
 include/drm/drm_gem_shmem_helper.h         |  1 +
 3 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 06ef4e5adb7d..4ffcf6ed46f5 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -924,6 +924,21 @@ void drm_gem_shmem_vunmap(struct drm_gem_shmem_object *shmem, struct iosys_map *
 	dma_resv_unlock(obj->resv);
 }
 EXPORT_SYMBOL_IF_KUNIT(drm_gem_shmem_vunmap);
+
+int drm_gem_shmem_madvise(struct drm_gem_shmem_object *shmem, int madv)
+{
+	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_madvise_locked(shmem, madv);
+	dma_resv_unlock(obj->resv);
+
+	return ret;
+}
+EXPORT_SYMBOL_IF_KUNIT(drm_gem_shmem_madvise);
 #endif
 
 MODULE_DESCRIPTION("DRM SHMEM memory-management helpers");
diff --git a/drivers/gpu/drm/tests/drm_gem_shmem_test.c b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
index 3e7c6f20fbcc..d639848e3c8e 100644
--- a/drivers/gpu/drm/tests/drm_gem_shmem_test.c
+++ b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
@@ -292,17 +292,17 @@ static void drm_gem_shmem_test_madvise(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_madvise_locked(shmem, 1);
+	ret = drm_gem_shmem_madvise(shmem, 1);
 	KUNIT_EXPECT_TRUE(test, ret);
 	KUNIT_ASSERT_EQ(test, shmem->madv, 1);
 
 	/* Set madv to a negative value */
-	ret = drm_gem_shmem_madvise_locked(shmem, -1);
+	ret = drm_gem_shmem_madvise(shmem, -1);
 	KUNIT_EXPECT_FALSE(test, ret);
 	KUNIT_ASSERT_EQ(test, shmem->madv, -1);
 
 	/* Check that madv cannot be set back to a positive value */
-	ret = drm_gem_shmem_madvise_locked(shmem, 0);
+	ret = drm_gem_shmem_madvise(shmem, 0);
 	KUNIT_EXPECT_FALSE(test, ret);
 	KUNIT_ASSERT_EQ(test, shmem->madv, -1);
 }
@@ -330,7 +330,7 @@ static void drm_gem_shmem_test_purge(struct kunit *test)
 	ret = drm_gem_shmem_is_purgeable(shmem);
 	KUNIT_EXPECT_FALSE(test, ret);
 
-	ret = drm_gem_shmem_madvise_locked(shmem, 1);
+	ret = drm_gem_shmem_madvise(shmem, 1);
 	KUNIT_EXPECT_TRUE(test, ret);
 
 	/* The scatter/gather table will be freed by drm_gem_shmem_free */
diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h
index 6924ee226655..3dd93e2df709 100644
--- a/include/drm/drm_gem_shmem_helper.h
+++ b/include/drm/drm_gem_shmem_helper.h
@@ -310,6 +310,7 @@ struct drm_gem_object *drm_gem_shmem_prime_import_no_map(struct drm_device *dev,
 #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);
+int drm_gem_shmem_madvise(struct drm_gem_shmem_object *shmem, int madv);
 #endif
 
 #endif /* __DRM_GEM_SHMEM_HELPER_H__ */
-- 
2.52.0

Re: [PATCH 4/5] drm/tests: shmem: Hold reservation lock around madvise

[Boris Brezillon]

On Fri, 12 Dec 2025 17:00:35 +0100
Thomas Zimmermann <tzimmermann@suse.de> wrote:

> Acquire and release the GEM object's reservation lock around calls
> to the object's madvide operation. The tests use
> drm_gem_shmem_madvise_locked(), which led to errors such as show below.
> 
> [   58.339389] WARNING: CPU: 1 PID: 1352 at drivers/gpu/drm/drm_gem_shmem_helper.c:499 drm_gem_shmem_madvise_locked+0xde/0x140
> 
> Only export the new helper drm_gem_shmem_madvise() for Kunit tests.
> This is not an interface 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>

> ---
>  drivers/gpu/drm/drm_gem_shmem_helper.c     | 15 +++++++++++++++
>  drivers/gpu/drm/tests/drm_gem_shmem_test.c |  8 ++++----
>  include/drm/drm_gem_shmem_helper.h         |  1 +
>  3 files changed, 20 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
> index 06ef4e5adb7d..4ffcf6ed46f5 100644
> --- a/drivers/gpu/drm/drm_gem_shmem_helper.c
> +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
> @@ -924,6 +924,21 @@ void drm_gem_shmem_vunmap(struct drm_gem_shmem_object *shmem, struct iosys_map *
>  	dma_resv_unlock(obj->resv);
>  }
>  EXPORT_SYMBOL_IF_KUNIT(drm_gem_shmem_vunmap);
> +
> +int drm_gem_shmem_madvise(struct drm_gem_shmem_object *shmem, int madv)
> +{
> +	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_madvise_locked(shmem, madv);
> +	dma_resv_unlock(obj->resv);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_IF_KUNIT(drm_gem_shmem_madvise);
>  #endif
>  
>  MODULE_DESCRIPTION("DRM SHMEM memory-management helpers");
> diff --git a/drivers/gpu/drm/tests/drm_gem_shmem_test.c b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
> index 3e7c6f20fbcc..d639848e3c8e 100644
> --- a/drivers/gpu/drm/tests/drm_gem_shmem_test.c
> +++ b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
> @@ -292,17 +292,17 @@ static void drm_gem_shmem_test_madvise(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_madvise_locked(shmem, 1);
> +	ret = drm_gem_shmem_madvise(shmem, 1);
>  	KUNIT_EXPECT_TRUE(test, ret);
>  	KUNIT_ASSERT_EQ(test, shmem->madv, 1);
>  
>  	/* Set madv to a negative value */
> -	ret = drm_gem_shmem_madvise_locked(shmem, -1);
> +	ret = drm_gem_shmem_madvise(shmem, -1);
>  	KUNIT_EXPECT_FALSE(test, ret);
>  	KUNIT_ASSERT_EQ(test, shmem->madv, -1);
>  
>  	/* Check that madv cannot be set back to a positive value */
> -	ret = drm_gem_shmem_madvise_locked(shmem, 0);
> +	ret = drm_gem_shmem_madvise(shmem, 0);
>  	KUNIT_EXPECT_FALSE(test, ret);
>  	KUNIT_ASSERT_EQ(test, shmem->madv, -1);
>  }
> @@ -330,7 +330,7 @@ static void drm_gem_shmem_test_purge(struct kunit *test)
>  	ret = drm_gem_shmem_is_purgeable(shmem);
>  	KUNIT_EXPECT_FALSE(test, ret);
>  
> -	ret = drm_gem_shmem_madvise_locked(shmem, 1);
> +	ret = drm_gem_shmem_madvise(shmem, 1);
>  	KUNIT_EXPECT_TRUE(test, ret);
>  
>  	/* The scatter/gather table will be freed by drm_gem_shmem_free */
> diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h
> index 6924ee226655..3dd93e2df709 100644
> --- a/include/drm/drm_gem_shmem_helper.h
> +++ b/include/drm/drm_gem_shmem_helper.h
> @@ -310,6 +310,7 @@ struct drm_gem_object *drm_gem_shmem_prime_import_no_map(struct drm_device *dev,
>  #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);
> +int drm_gem_shmem_madvise(struct drm_gem_shmem_object *shmem, int madv);
>  #endif
>  
>  #endif /* __DRM_GEM_SHMEM_HELPER_H__ */

[PATCH 5/5] drm/tests: shmem: Hold reservation lock around purge

[Thomas Zimmermann]

Acquire and release the GEM object's reservation lock around calls
to the object's purge operation. The tests use
drm_gem_shmem_purge_locked(), which led to errors such as show below.

[   58.709128] WARNING: CPU: 1 PID: 1354 at drivers/gpu/drm/drm_gem_shmem_helper.c:515 drm_gem_shmem_purge_locked+0x51c/0x740

Only export the new helper drm_gem_shmem_purge() for Kunit tests.
This is not an interface 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+
---
 drivers/gpu/drm/drm_gem_shmem_helper.c     | 15 +++++++++++++++
 drivers/gpu/drm/tests/drm_gem_shmem_test.c |  4 +++-
 include/drm/drm_gem_shmem_helper.h         |  1 +
 3 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 4ffcf6ed46f5..dfc24392cb61 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -939,6 +939,21 @@ int drm_gem_shmem_madvise(struct drm_gem_shmem_object *shmem, int madv)
 	return ret;
 }
 EXPORT_SYMBOL_IF_KUNIT(drm_gem_shmem_madvise);
+
+int drm_gem_shmem_purge(struct drm_gem_shmem_object *shmem)
+{
+	struct drm_gem_object *obj = &shmem->base;
+	int ret;
+
+	ret = dma_resv_lock_interruptible(obj->resv, NULL);
+	if (ret)
+		return ret;
+	drm_gem_shmem_purge_locked(shmem);
+	dma_resv_unlock(obj->resv);
+
+	return 0;
+}
+EXPORT_SYMBOL_IF_KUNIT(drm_gem_shmem_purge);
 #endif
 
 MODULE_DESCRIPTION("DRM SHMEM memory-management helpers");
diff --git a/drivers/gpu/drm/tests/drm_gem_shmem_test.c b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
index d639848e3c8e..4b459f21acfd 100644
--- a/drivers/gpu/drm/tests/drm_gem_shmem_test.c
+++ b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
@@ -340,7 +340,9 @@ static void drm_gem_shmem_test_purge(struct kunit *test)
 	ret = drm_gem_shmem_is_purgeable(shmem);
 	KUNIT_EXPECT_TRUE(test, ret);
 
-	drm_gem_shmem_purge_locked(shmem);
+	ret = drm_gem_shmem_purge(shmem);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
 	KUNIT_EXPECT_NULL(test, shmem->pages);
 	KUNIT_EXPECT_NULL(test, shmem->sgt);
 	KUNIT_EXPECT_EQ(test, shmem->madv, -1);
diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h
index 3dd93e2df709..8d56970d7eed 100644
--- a/include/drm/drm_gem_shmem_helper.h
+++ b/include/drm/drm_gem_shmem_helper.h
@@ -311,6 +311,7 @@ struct drm_gem_object *drm_gem_shmem_prime_import_no_map(struct drm_device *dev,
 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);
 int drm_gem_shmem_madvise(struct drm_gem_shmem_object *shmem, int madv);
+int drm_gem_shmem_purge(struct drm_gem_shmem_object *shmem);
 #endif
 
 #endif /* __DRM_GEM_SHMEM_HELPER_H__ */
-- 
2.52.0

Re: [PATCH 5/5] drm/tests: shmem: Hold reservation lock around purge

[Boris Brezillon]

On Fri, 12 Dec 2025 17:00:36 +0100
Thomas Zimmermann <tzimmermann@suse.de> wrote:

> Acquire and release the GEM object's reservation lock around calls
> to the object's purge operation. The tests use
> drm_gem_shmem_purge_locked(), which led to errors such as show below.
> 
> [   58.709128] WARNING: CPU: 1 PID: 1354 at drivers/gpu/drm/drm_gem_shmem_helper.c:515 drm_gem_shmem_purge_locked+0x51c/0x740
> 
> Only export the new helper drm_gem_shmem_purge() for Kunit tests.
> This is not an interface 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>

> ---
>  drivers/gpu/drm/drm_gem_shmem_helper.c     | 15 +++++++++++++++
>  drivers/gpu/drm/tests/drm_gem_shmem_test.c |  4 +++-
>  include/drm/drm_gem_shmem_helper.h         |  1 +
>  3 files changed, 19 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
> index 4ffcf6ed46f5..dfc24392cb61 100644
> --- a/drivers/gpu/drm/drm_gem_shmem_helper.c
> +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
> @@ -939,6 +939,21 @@ int drm_gem_shmem_madvise(struct drm_gem_shmem_object *shmem, int madv)
>  	return ret;
>  }
>  EXPORT_SYMBOL_IF_KUNIT(drm_gem_shmem_madvise);
> +
> +int drm_gem_shmem_purge(struct drm_gem_shmem_object *shmem)
> +{
> +	struct drm_gem_object *obj = &shmem->base;
> +	int ret;
> +
> +	ret = dma_resv_lock_interruptible(obj->resv, NULL);
> +	if (ret)
> +		return ret;
> +	drm_gem_shmem_purge_locked(shmem);
> +	dma_resv_unlock(obj->resv);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_IF_KUNIT(drm_gem_shmem_purge);
>  #endif
>  
>  MODULE_DESCRIPTION("DRM SHMEM memory-management helpers");
> diff --git a/drivers/gpu/drm/tests/drm_gem_shmem_test.c b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
> index d639848e3c8e..4b459f21acfd 100644
> --- a/drivers/gpu/drm/tests/drm_gem_shmem_test.c
> +++ b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
> @@ -340,7 +340,9 @@ static void drm_gem_shmem_test_purge(struct kunit *test)
>  	ret = drm_gem_shmem_is_purgeable(shmem);
>  	KUNIT_EXPECT_TRUE(test, ret);
>  
> -	drm_gem_shmem_purge_locked(shmem);
> +	ret = drm_gem_shmem_purge(shmem);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
>  	KUNIT_EXPECT_NULL(test, shmem->pages);
>  	KUNIT_EXPECT_NULL(test, shmem->sgt);
>  	KUNIT_EXPECT_EQ(test, shmem->madv, -1);
> diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h
> index 3dd93e2df709..8d56970d7eed 100644
> --- a/include/drm/drm_gem_shmem_helper.h
> +++ b/include/drm/drm_gem_shmem_helper.h
> @@ -311,6 +311,7 @@ struct drm_gem_object *drm_gem_shmem_prime_import_no_map(struct drm_device *dev,
>  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);
>  int drm_gem_shmem_madvise(struct drm_gem_shmem_object *shmem, int madv);
> +int drm_gem_shmem_purge(struct drm_gem_shmem_object *shmem);
>  #endif
>  
>  #endif /* __DRM_GEM_SHMEM_HELPER_H__ */