On 11/04/2025 16:03, Adrián Larumbe wrote:

Allow UM to label a BO for which it possesses a DRM handle.

Signed-off-by: Adrián Larumbe adrian.larumbe@collabora.com Reviewed-by: Liviu Dudau liviu.dudau@arm.com Reviewed-by: Boris Brezillon boris.brezillon@collabora.com

Reviewed-by: Steven Price steven.price@arm.com

Although very minor NITs below which you can consider.

---

drivers/gpu/drm/panthor/panthor_drv.c | 42 ++++++++++++++++++++++++++- drivers/gpu/drm/panthor/panthor_gem.h | 2 ++ include/uapi/drm/panthor_drm.h | 23 +++++++++++++++ 3 files changed, 66 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/panthor/panthor_drv.c b/drivers/gpu/drm/panthor/panthor_drv.c index 06fe46e32073..983b24f1236c 100644 --- a/drivers/gpu/drm/panthor/panthor_drv.c +++ b/drivers/gpu/drm/panthor/panthor_drv.c @@ -1331,6 +1331,44 @@ static int panthor_ioctl_vm_get_state(struct drm_device *ddev, void *data, return 0; } +static int panthor_ioctl_bo_set_label(struct drm_device *ddev, void *data,

• 		  struct drm_file *file)
  

+{

• struct drm_panthor_bo_set_label *args = data;
• struct drm_gem_object *obj;
• const char *label;
• int ret = 0;
• obj = drm_gem_object_lookup(file, args->handle);
• if (!obj)

• return -ENOENT;
  

• if (args->size && args->label) {

• if (args->size > PANTHOR_BO_LABEL_MAXLEN) {
  

• 	ret = -E2BIG;
  

• 	goto err_label;
  

• }
  

• label = strndup_user(u64_to_user_ptr(args->label), args->size);
  

• if (IS_ERR(label)) {
  

• 	ret = PTR_ERR(label);
  

• 	goto err_label;
  

• }
  

• } else if (args->size && !args->label) {

• ret = -EINVAL;
  

• goto err_label;
  

• } else {

• label = NULL;
  

• }
• panthor_gem_bo_set_label(obj, label);

+err_label:

• drm_gem_object_put(obj);
• return ret;

+}

static int panthor_open(struct drm_device *ddev, struct drm_file *file) { @@ -1400,6 +1438,7 @@ static const struct drm_ioctl_desc panthor_drm_driver_ioctls[] = { PANTHOR_IOCTL(TILER_HEAP_CREATE, tiler_heap_create, DRM_RENDER_ALLOW), PANTHOR_IOCTL(TILER_HEAP_DESTROY, tiler_heap_destroy, DRM_RENDER_ALLOW), PANTHOR_IOCTL(GROUP_SUBMIT, group_submit, DRM_RENDER_ALLOW),

• PANTHOR_IOCTL(BO_SET_LABEL, bo_set_label, DRM_RENDER_ALLOW),

}; static int panthor_mmap(struct file *filp, struct vm_area_struct *vma) @@ -1509,6 +1548,7 @@ static void panthor_debugfs_init(struct drm_minor *minor)

• • 1.2 - adds DEV_QUERY_GROUP_PRIORITIES_INFO query

•   - adds PANTHOR_GROUP_PRIORITY_REALTIME priority
  

• • 1.3 - adds DRM_PANTHOR_GROUP_STATE_INNOCENT flag

• • • 1.4 - adds DRM_IOCTL_PANTHOR_BO_SET_LABEL ioctl
  */

static const struct drm_driver panthor_drm_driver = { .driver_features = DRIVER_RENDER | DRIVER_GEM | DRIVER_SYNCOBJ | @@ -1522,7 +1562,7 @@ static const struct drm_driver panthor_drm_driver = { .name = "panthor", .desc = "Panthor DRM driver", .major = 1,

• .minor = 3,

• .minor = 4,

.gem_create_object = panthor_gem_create_object, .gem_prime_import_sg_table = drm_gem_shmem_prime_import_sg_table, diff --git a/drivers/gpu/drm/panthor/panthor_gem.h b/drivers/gpu/drm/panthor/panthor_gem.h index af0d77338860..beba066b4974 100644 --- a/drivers/gpu/drm/panthor/panthor_gem.h +++ b/drivers/gpu/drm/panthor/panthor_gem.h @@ -13,6 +13,8 @@ struct panthor_vm; +#define PANTHOR_BO_LABEL_MAXLEN PAGE_SIZE

/**

• struct panthor_gem_object - Driver specific GEM object.

*/ diff --git a/include/uapi/drm/panthor_drm.h b/include/uapi/drm/panthor_drm.h index 97e2c4510e69..12b1994499a9 100644 --- a/include/uapi/drm/panthor_drm.h +++ b/include/uapi/drm/panthor_drm.h @@ -127,6 +127,9 @@ enum drm_panthor_ioctl_id { /** @DRM_PANTHOR_TILER_HEAP_DESTROY: Destroy a tiler heap. */ DRM_PANTHOR_TILER_HEAP_DESTROY,

• /** @DRM_PANTHOR_BO_SET_LABEL: Label a BO. */
• DRM_PANTHOR_BO_SET_LABEL,

}; /** @@ -977,6 +980,24 @@ struct drm_panthor_tiler_heap_destroy { __u32 pad; }; +/**

• • struct drm_panthor_bo_set_label - Arguments passed to DRM_IOCTL_PANTHOR_BO_SET_LABEL
• */

+struct drm_panthor_bo_set_label {

• /** @handle: Handle of the buffer object to label. */
• __u32 handle;
• /**

• * @size: Length of the label, including the NULL terminator.
  

• *
  

• * Cannot be greater than the OS page size.
  

• */
  

• __u32 size;
• /** @label: User pointer to a NULL-terminated string */
• __u64 label;

+};

First very minor NIT: * NULL is a pointer, i.e. (void*)0 * NUL is the ASCII code point '\0'. So it's a NUL-terminated string.

Second NIT: We don't actually need 'size' - since the string is NUL-terminated we can just strndup_user(__user_pointer__, PAGE_SIZE). As things stand we validate that strlen(label) < size <= PAGE_SIZE - which is a little odd (user space might as well just pass PAGE_SIZE rather than calculate the actual length).

Thanks, Steve

/**

• DRM_IOCTL_PANTHOR() - Build a Panthor IOCTL number
• @__access: Access type. Must be R, W or RW.

@@ -1019,6 +1040,8 @@ enum { DRM_IOCTL_PANTHOR(WR, TILER_HEAP_CREATE, tiler_heap_create), DRM_IOCTL_PANTHOR_TILER_HEAP_DESTROY = DRM_IOCTL_PANTHOR(WR, TILER_HEAP_DESTROY, tiler_heap_destroy),

• DRM_IOCTL_PANTHOR_BO_SET_LABEL =

• DRM_IOCTL_PANTHOR(WR, BO_SET_LABEL, bo_set_label),
  

}; #if defined(__cplusplus)