DRM_IOCTL_HANDLE_SET_LABEL lets you label buffers associated
with a handle, making it easier to debug issues in userspace
applications.
DRM_IOCTL_HANDLE_GET_LABEL lets you read the label associated
with a buffer.
Changes in v2:
- Hoist the IOCTL up into the drm_driver framework
Changes in v3:
- Introduce a drm_gem_set_label for drivers to use internally
in order to label a GEM object
- Hoist string copying up into the IOCTL
- Fix documentation
- Move actual gem labeling into drm_gem_adopt_label
Changes in v4:
- Refactor IOCTL call to only perform string duplication and move
all gem lookup logic into GEM specific call
Changes in v5:
- Fix issues pointed out by kbuild test robot
- Cleanup minor issues around kfree and out/err labels
- Fixed API documentation issues
- Rename to DRM_IOCTL_HANDLE_SET_LABEL
- Introduce a DRM_IOCTL_HANDLE_GET_LABEL to read labels
- Added some documentation for consumers of this IOCTL
- Ensure that label's cannot be longer than PAGE_SIZE
- Set a default label value
- Drop useless warning
- Properly return length of label to userspace even if
userspace did not allocate memory for label.
Changes in v6:
- Wrap code to make better use of 80 char limit
- Drop redundant copies of the label
- Protect concurrent access to labels
- Improved documentation
- Refactor setter/getter ioctl's to be static
- Return EINVAL when label length > PAGE_SIZE
- Simplify code by calling the default GEM label'ing
function for all drivers using GEM
- Do not error out when fetching empty labels
- Refactor flags to the u32 type and add documentation
- Refactor ioctls to use correct DRM_IOCTL{R,W,WR} macros
- Return length of copied label to userspace
Signed-off-by: Rohan Garg <rohan.garg(a)collabora.com>
---
drivers/gpu/drm/drm_gem.c | 68 +++++++++++++++++++++++++++++++++
drivers/gpu/drm/drm_internal.h | 5 +++
drivers/gpu/drm/drm_ioctl.c | 70 ++++++++++++++++++++++++++++++++++
include/drm/drm_drv.h | 30 +++++++++++++++
include/drm/drm_gem.h | 19 +++++++++
include/uapi/drm/drm.h | 25 +++++++++++-
6 files changed, 216 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index efc0367841e2..942479dc152f 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -154,8 +154,10 @@ void drm_gem_private_object_init(struct drm_device *dev,
obj->dev = dev;
obj->filp = NULL;
+ obj->label = NULL;
kref_init(&obj->refcount);
+ mutex_init(&obj->bo_lock);
obj->handle_count = 0;
obj->size = size;
dma_resv_init(&obj->_resv);
@@ -940,6 +942,69 @@ drm_gem_release(struct drm_device *dev, struct drm_file *file_private)
idr_destroy(&file_private->object_idr);
}
+int drm_gem_set_label(struct drm_device *dev, struct drm_file *file_priv,
+ struct drm_handle_label *args)
+{
+ struct drm_gem_object *gem_obj;
+ struct pid *_pid = get_task_pid(current, PIDTYPE_PID);
+ char *label;
+
+ gem_obj = drm_gem_object_lookup(file_priv, args->handle);
+ if (!gem_obj) {
+ DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle);
+ return -ENOENT;
+ }
+
+ if (args->len && args->label)
+ label = strndup_user(u64_to_user_ptr(args->label),
+ args->len + 1);
+ else
+ label = NULL;
+
+ drm_gem_adopt_label(gem_obj, label);
+ drm_gem_object_put(gem_obj);
+ return args->len;
+}
+EXPORT_SYMBOL(drm_gem_set_label);
+
+void drm_gem_adopt_label(struct drm_gem_object *gem_obj, const char *label)
+{
+ mutex_lock(&gem_obj->bo_lock);
+ kfree(gem_obj->label);
+ gem_obj->label = label;
+ mutex_unlock(&gem_obj->bo_lock);
+}
+EXPORT_SYMBOL(drm_gem_adopt_label);
+
+int drm_gem_get_label(struct drm_device *dev, struct drm_file *file_priv,
+ struct drm_handle_label *args)
+{
+ struct drm_gem_object *gem_obj;
+ int len, ret;
+
+ gem_obj = drm_gem_object_lookup(file_priv, args->handle);
+ if (!gem_obj) {
+ DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle);
+ return -ENOENT;
+ }
+
+ if (!gem_obj->label) {
+ args->label = NULL;
+ args->len = 0;
+ return 0;
+ }
+
+ mutex_lock(&gem_obj->bo_lock);
+ len = strlen(gem_obj->label);
+ ret = copy_to_user(u64_to_user_ptr(args->label), gem_obj->label,
+ min(args->len, len));
+ mutex_unlock(&gem_obj->bo_lock);
+ args->len = len;
+ drm_gem_object_put(gem_obj);
+ return ret;
+}
+EXPORT_SYMBOL(drm_gem_get_label);
+
/**
* drm_gem_object_release - release GEM buffer object resources
* @obj: GEM buffer object
@@ -957,6 +1022,9 @@ drm_gem_object_release(struct drm_gem_object *obj)
dma_resv_fini(&obj->_resv);
drm_gem_free_mmap_offset(obj);
+
+ kfree(obj->label);
+ mutex_destroy(&obj->bo_lock);
}
EXPORT_SYMBOL(drm_gem_object_release);
diff --git a/drivers/gpu/drm/drm_internal.h b/drivers/gpu/drm/drm_internal.h
index 2470a352730b..73fd87860100 100644
--- a/drivers/gpu/drm/drm_internal.h
+++ b/drivers/gpu/drm/drm_internal.h
@@ -161,6 +161,11 @@ int drm_gem_pin(struct drm_gem_object *obj);
void drm_gem_unpin(struct drm_gem_object *obj);
void *drm_gem_vmap(struct drm_gem_object *obj);
void drm_gem_vunmap(struct drm_gem_object *obj, void *vaddr);
+int drm_gem_set_label(struct drm_device *dev, struct drm_file *file_priv,
+ struct drm_handle_label *args);
+void drm_gem_adopt_label(struct drm_gem_object *gem_obj, const char *label);
+int drm_gem_get_label(struct drm_device *dev, struct drm_file *file_priv,
+ struct drm_handle_label *args);
/* drm_debugfs.c drm_debugfs_crc.c */
#if defined(CONFIG_DEBUG_FS)
diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
index 0fb9da24eaa4..04ff75e53349 100644
--- a/drivers/gpu/drm/drm_ioctl.c
+++ b/drivers/gpu/drm/drm_ioctl.c
@@ -573,6 +573,72 @@ EXPORT_SYMBOL(drm_ioctl_permit);
#define DRM_LEGACY_IOCTL_DEF(ioctl, _func, _flags) DRM_IOCTL_DEF(ioctl, drm_invalid_op, _flags)
#endif
+/**
+ * drm_handle_set_label_ioctl - Assign a string label to a handle
+ * @dev: DRM device for the ioctl
+ * @data: user argument
+ * @file_priv: drm file-private structure
+ *
+ * This is typically targeted at user space drivers to label buffer objects
+ * with relevant information to provide human readable information about the
+ * contents of a buffer (for eg: a UBO, command buffer, shader, etc).
+ *
+ * Label length *must* not be larger than PAGE_SIZE.
+ *
+ * Returns:
+ * Length of label when setting a label succeeds, negative errno otherwise.
+ */
+
+static int drm_handle_set_label_ioctl(struct drm_device *dev,
+ void *data, struct drm_file *file_priv)
+{
+ char *label;
+ struct drm_handle_label *args = data;
+
+ if (args->len > PAGE_SIZE)
+ return -EINVAL;
+
+ if (!dev->driver->set_label && !drm_core_check_feature(dev, DRIVER_GEM))
+ return -EOPNOTSUPP;
+
+ if (dev->driver->set_label)
+ return dev->driver->set_label(dev, file_priv, args);
+
+ if (drm_core_check_feature(dev, DRIVER_GEM))
+ return drm_gem_set_label(dev, file_priv, args);
+}
+
+/**
+ * drm_handle_get_label_ioctl - Fetches the label associated with a handle
+ * @dev: DRM device for the ioctl
+ * @data: user argument
+ * @file_priv: drm file-private structure
+ *
+ * This is targeted at user space drivers to read back the labels associated
+ * with a buffer object. You'll need to call this ioctl twice in order to be
+ * able to read back the entnire label. Optionally, userspace can also read
+ * back the label partially by passing a
+ * fixed length in `struct drm_handle_label`.
+ *
+ * Returns:
+ * Length of label copied back to userspace.
+ */
+
+static int drm_handle_get_label_ioctl(struct drm_device *dev,
+ void *data, struct drm_file *file_priv)
+{
+ struct drm_handle_label *args = data;
+
+ if (!dev->driver->get_label && !drm_core_check_feature(dev, DRIVER_GEM))
+ return -EOPNOTSUPP;
+
+ if (dev->driver->get_label)
+ return dev->driver->get_label(dev, file_priv, args);
+
+ if (drm_core_check_feature(dev, DRIVER_GEM))
+ return drm_gem_get_label(dev, file_priv, args);
+}
+
/* Ioctl table */
static const struct drm_ioctl_desc drm_ioctls[] = {
DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version, DRM_RENDER_ALLOW),
@@ -715,6 +781,10 @@ static const struct drm_ioctl_desc drm_ioctls[] = {
DRM_IOCTL_DEF(DRM_IOCTL_MODE_LIST_LESSEES, drm_mode_list_lessees_ioctl, DRM_MASTER),
DRM_IOCTL_DEF(DRM_IOCTL_MODE_GET_LEASE, drm_mode_get_lease_ioctl, DRM_MASTER),
DRM_IOCTL_DEF(DRM_IOCTL_MODE_REVOKE_LEASE, drm_mode_revoke_lease_ioctl, DRM_MASTER),
+ DRM_IOCTL_DEF(DRM_IOCTL_HANDLE_SET_LABEL, drm_handle_set_label_ioctl,
+ DRM_RENDER_ALLOW),
+ DRM_IOCTL_DEF(DRM_IOCTL_HANDLE_GET_LABEL, drm_handle_get_label_ioctl,
+ DRM_RENDER_ALLOW),
};
#define DRM_CORE_IOCTL_COUNT ARRAY_SIZE( drm_ioctls )
diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
index bb924cddc09c..6fcb7b9ff322 100644
--- a/include/drm/drm_drv.h
+++ b/include/drm/drm_drv.h
@@ -540,6 +540,36 @@ struct drm_driver {
struct drm_device *dev,
uint32_t handle);
+ /**
+ * @set_label:
+ *
+ * Label a buffer object
+ *
+ * Called by the user via ioctl.
+ *
+ * Returns:
+ *
+ * Length of label on success, negative errno on failure.
+ */
+ int (*set_label)(struct drm_device *dev,
+ struct drm_file *file_priv,
+ struct drm_handle_label *args);
+
+ /**
+ * @get_label:
+ *
+ * Read the label of a buffer object.
+ *
+ * Called by the user via ioctl.
+ *
+ * Returns:
+ *
+ * Length of label on success, negative errno on failiure.
+ */
+ char *(*get_label)(struct drm_device *dev,
+ struct drm_file *file_priv,
+ struct drm_handle_label *args);
+
/**
* @gem_vm_ops: Driver private ops for this object
*
diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
index 2410ff0a8e86..064b080eb32f 100644
--- a/include/drm/drm_gem.h
+++ b/include/drm/drm_gem.h
@@ -250,6 +250,13 @@ struct drm_gem_object {
*/
int name;
+ /**
+ * @label:
+ *
+ * Label for this object, should be a human readable string.
+ */
+ char *label;
+
/**
* @dma_buf:
*
@@ -311,6 +318,13 @@ struct drm_gem_object {
*
*/
const struct drm_gem_object_funcs *funcs;
+
+ /**
+ * @bo_lock
+ *
+ * Protects buffer object labels
+ */
+ struct mutex bo_lock;
};
/**
@@ -418,5 +432,10 @@ int drm_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev,
int drm_gem_dumb_destroy(struct drm_file *file,
struct drm_device *dev,
uint32_t handle);
+int drm_gem_set_label(struct drm_device *dev, struct drm_file *file_priv,
+ struct drm_handle_label *args);
+void drm_gem_adopt_label(struct drm_gem_object *gem_obj, const char *label);
+int drm_gem_get_label(struct drm_device *dev, struct drm_file *file_priv,
+ struct drm_handle_label *args);
#endif /* __DRM_GEM_H__ */
diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
index 808b48a93330..2a7128271307 100644
--- a/include/uapi/drm/drm.h
+++ b/include/uapi/drm/drm.h
@@ -626,6 +626,27 @@ struct drm_gem_open {
__u64 size;
};
+/** struct drm_handle_label - ioctl argument for labelling BOs.
+ *
+ * This label's a BO with a userspace label
+ *
+ */
+struct drm_handle_label {
+ /** Handle for the object being labelled. */
+ __u32 handle;
+
+ /** Label and label length (len excludes the trailing NULL).
+ * Label length *MUST* be smaller than PAGE_SIZE.
+ * Label length can be smaller than actual length when reading
+ * the label back.
+ */
+ __u32 len;
+ __u64 label;
+
+ /** Flags .. Currently no flags are defined */
+ __u32 flags;
+};
+
#define DRM_CAP_DUMB_BUFFER 0x1
#define DRM_CAP_VBLANK_HIGH_CRTC 0x2
#define DRM_CAP_DUMB_PREFERRED_DEPTH 0x3
@@ -947,8 +968,10 @@ extern "C" {
#define DRM_IOCTL_SYNCOBJ_QUERY DRM_IOWR(0xCB, struct drm_syncobj_timeline_array)
#define DRM_IOCTL_SYNCOBJ_TRANSFER DRM_IOWR(0xCC, struct drm_syncobj_transfer)
#define DRM_IOCTL_SYNCOBJ_TIMELINE_SIGNAL DRM_IOWR(0xCD, struct drm_syncobj_timeline_array)
-
#define DRM_IOCTL_MODE_GETFB2 DRM_IOWR(0xCE, struct drm_mode_fb_cmd2)
+#define DRM_IOCTL_HANDLE_SET_LABEL DRM_IOW(0xCF, struct drm_handle_label)
+#define DRM_IOCTL_HANDLE_GET_LABEL DRM_IOWR(0xD0, struct drm_handle_label)
+
/**
* Device specific ioctls should only be in their respective headers
--
2.17.1
