[Intel-gfx] [PATCH] dma-buf: Switch to inline kerneldoc

Daniel Vetter
2021-06-23T16:19:21Z

Also review & update everything while we're at it.

This is prep work to smash a ton of stuff into the kerneldoc for
@resv.

v2: Move the doc for sysfs_entry.attachment_uid to the right place too
(Sam)

Acked-by: Christian König <christian.koenig@amd.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Nirmoy Das <nirmoy.das@amd.com>
Cc: Deepak R Varma <mh12gx2825@gmail.com>
Cc: Chen Li <chenli@uniontech.com>
Cc: Kevin Wang <kevin1.wang@amd.com>
Cc: linux-media@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
---
include/linux/dma-buf.h | 116 +++++++++++++++++++++++++++++++---------
1 file changed, 90 insertions(+), 26 deletions(-)

diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index 92eec38a03aa..81cebf414505 100644
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -289,30 +289,6 @@ struct dma_buf_ops {

/**
* struct dma_buf - shared buffer object
- * @size: size of the buffer; invariant over the lifetime of the buffer.
- * @file: file pointer used for sharing buffers across, and for refcounting.
- * @attachments: list of dma_buf_attachment that denotes all devices attached,
- * protected by dma_resv lock.
- * @ops: dma_buf_ops associated with this buffer object.
- * @lock: used internally to serialize list manipulation, attach/detach and
- * vmap/unmap
- * @vmapping_counter: used internally to refcnt the vmaps
- * @vmap_ptr: the current vmap ptr if vmapping_counter > 0
- * @exp_name: name of the exporter; useful for debugging.
- * @name: userspace-provided name; useful for accounting and debugging,
- * protected by @resv.
- * @name_lock: spinlock to protect name access
- * @owner: pointer to exporter module; used for refcounting when exporter is a
- * kernel module.
- * @list_node: node for dma_buf accounting and debugging.
- * @priv: exporter specific private data for this buffer object.
- * @resv: reservation object linked to this dma-buf
- * @poll: for userspace poll support
- * @cb_excl: for userspace poll support
- * @cb_shared: for userspace poll support
- * @sysfs_entry: for exposing information about this buffer in sysfs.
- * The attachment_uid member of @sysfs_entry is protected by dma_resv lock
- * and is incremented on each attach.
*
* This represents a shared buffer, created by calling dma_buf_export(). The
* userspace representation is a normal file descriptor, which can be created by
@@ -324,24 +300,100 @@ struct dma_buf_ops {
* Device DMA access is handled by the separate &struct dma_buf_attachment.
*/
struct dma_buf {
+ /**
+ * @size:
+ *
+ * Size of the buffer; invariant over the lifetime of the buffer.
+ */
size_t size;
+
+ /**
+ * @file:
+ *
+ * File pointer used for sharing buffers across, and for refcounting.
+ * See dma_buf_get() and dma_buf_put().
+ */
struct file *file;
+
+ /**
+ * @attachments:
+ *
+ * List of dma_buf_attachment that denotes all devices attached,
+ * protected by &dma_resv lock @resv.
+ */
struct list_head attachments;
+
+ /** @ops: dma_buf_ops associated with this buffer object. */
const struct dma_buf_ops *ops;
+
+ /**
+ * @lock:
+ *
+ * Used internally to serialize list manipulation, attach/detach and
+ * vmap/unmap. Note that in many cases this is superseeded by
+ * dma_resv_lock() on @resv.
+ */
struct mutex lock;
+
+ /**
+ * @vmapping_counter:
+ *
+ * Used internally to refcnt the vmaps returned by dma_buf_vmap().
+ * Protected by @lock.
+ */
unsigned vmapping_counter;
+
+ /**
+ * @vmap_ptr:
+ * The current vmap ptr if @vmapping_counter > 0. Protected by @lock.
+ */
struct dma_buf_map vmap_ptr;
+
+ /**
+ * @exp_name:
+ *
+ * Name of the exporter; useful for debugging. See the
+ * DMA_BUF_SET_NAME IOCTL.
+ */
const char *exp_name;
+
+ /**
+ * @name:
+ *
+ * Userspace-provided name; useful for accounting and debugging,
+ * protected by dma_resv_lock() on @resv and @name_lock for read access.
+ */
const char *name;
+
+ /** @name_lock: Spinlock to protect name acces for read access. */
spinlock_t name_lock;
+
+ /**
+ * @owner:
+ *
+ * Pointer to exporter module; used for refcounting when exporter is a
+ * kernel module.
+ */
struct module *owner;
+
+ /** @list_node: node for dma_buf accounting and debugging. */
struct list_head list_node;
+
+ /** @priv: exporter specific private data for this buffer object. */
void *priv;
+
+ /**
+ * @resv:
+ *
+ * Reservation object linked to this dma-buf.
+ */
struct dma_resv *resv;

- /* poll support */
+ /** @poll: for userspace poll support */
wait_queue_head_t poll;

+ /** @cb_excl: for userspace poll support */
+ /** @cb_shared: for userspace poll support */
struct dma_buf_poll_cb_t {
struct dma_fence_cb cb;
wait_queue_head_t *poll;
@@ -349,10 +401,22 @@ struct dma_buf {
__poll_t active;
} cb_excl, cb_shared;
#ifdef CONFIG_DMABUF_SYSFS_STATS
- /* for sysfs stats */
+ /**
+ * @sysfs_entry:
+ *
+ * For exposing information about this buffer in sysfs. See also
+ * `DMA-BUF statistics`_ for the uapi this enables.
+ */
struct dma_buf_sysfs_entry {
struct kobject kobj;
struct dma_buf *dmabuf;
+
+ /**
+ * @sysfs_entry.attachment_uid:
+ *
+ * This is protected by the dma_resv_lock() on @resv and is
+ * incremented on each attach.
+ */
unsigned int attachment_uid;
struct kset *attach_stats_kset;
} *sysfs_entry;
--
2.32.0.rc2