| Message ID | 20230901124414.48497-18-benjamin.gaignard@collabora.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add DELETE_BUF ioctl | expand |
On 01/09/2023 14:44, Benjamin Gaignard wrote: > VIDIOC_DELETE_BUFS ioctl allows to delete buffers from a queue. > The number of buffers to delete in given by count field of > struct v4l2_delete_buffers and the range start at the index > specified in the same structure. > > Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com> > --- > v6: > - Add lock in vb2_core_delete_buf() > - Fix typo and comments > - Add flags in VIDIOC_DELETE_BUFS decalaration > > .../userspace-api/media/v4l/user-func.rst | 1 + > .../media/v4l/vidioc-delete-bufs.rst | 73 +++++++++++++++++++ > .../media/common/videobuf2/videobuf2-core.c | 24 ++++++ > .../media/common/videobuf2/videobuf2-v4l2.c | 38 +++++++++- > drivers/media/v4l2-core/v4l2-dev.c | 1 + > drivers/media/v4l2-core/v4l2-ioctl.c | 17 +++++ > include/media/v4l2-ioctl.h | 4 + > include/media/videobuf2-core.h | 9 +++ > include/media/videobuf2-v4l2.h | 11 +++ > include/uapi/linux/videodev2.h | 16 ++++ > 10 files changed, 193 insertions(+), 1 deletion(-) > create mode 100644 Documentation/userspace-api/media/v4l/vidioc-delete-bufs.rst > > diff --git a/Documentation/userspace-api/media/v4l/user-func.rst b/Documentation/userspace-api/media/v4l/user-func.rst > index 15ff0bf7bbe6..3fd567695477 100644 > --- a/Documentation/userspace-api/media/v4l/user-func.rst > +++ b/Documentation/userspace-api/media/v4l/user-func.rst > @@ -17,6 +17,7 @@ Function Reference > vidioc-dbg-g-chip-info > vidioc-dbg-g-register > vidioc-decoder-cmd > + vidioc-delete-bufs > vidioc-dqevent > vidioc-dv-timings-cap > vidioc-encoder-cmd > diff --git a/Documentation/userspace-api/media/v4l/vidioc-delete-bufs.rst b/Documentation/userspace-api/media/v4l/vidioc-delete-bufs.rst > new file mode 100644 > index 000000000000..a55fe6331fc8 > --- /dev/null > +++ b/Documentation/userspace-api/media/v4l/vidioc-delete-bufs.rst > @@ -0,0 +1,73 @@ > +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later > +.. c:namespace:: V4L > + > +.. _VIDIOC_DELETE_BUFS: > + > +************************ > +ioctl VIDIOC_DELETE_BUFS > +************************ > + > +Name > +==== > + > +VIDIOC_DELETE_BUFS - Deletes buffers from a queue > + > +Synopsis > +======== > + > +.. c:macro:: VIDIOC_DELETE_BUFs > + > +``int ioctl(int fd, VIDIOC_DELETE_BUFs, struct v4l2_delete_buffers *argp)`` > + > +Arguments > +========= > + > +``fd`` > + File descriptor returned by :c:func:`open()`. > + > +``argp`` > + Pointer to struct :c:type:`v4l2_delete_buffers`. > + > +Description > +=========== > + > +Applications can optionally call the :ref:`VIDIOC_DELETE_BUFS` ioctl to > +delete buffers from a queue. > + > +.. c:type:: v4l2_delete_buffers > + > +.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.5cm}| > + > +.. flat-table:: struct v4l2_delete_buffers > + :header-rows: 0 > + :stub-columns: 0 > + :widths: 1 1 2 > + > + * - __u32 > + - ``index`` > + - The starting buffer index to delete. > + * - __u32 > + - ``count`` > + - The number of buffers to be deleted. That's not quite correct. This function will delete the buffers with indices index until index+count-1. And indices in that range have to be valid buffers, i.e. you can't have already deleted buffers in that range. Or should we allow that? It is a fair question. All buffers also have to be in the DEQUEUED state. The text above suggests that given the following valid indices: 0, 1, 3, 4 (so the buffer with index 2 was already deleted) deleting 2 buffers from index 1 would delete buffers 1, 3. When in fact it will attempt to delete buffers 1 and 2. Also document explicitly that calling this with count=0 (and perhaps index=0 as well?) can be used to check if this ioctl is supported. > + * - __u32 > + - ``type`` > + - Type of the stream or buffers, this is the same as the struct > + :c:type:`v4l2_format` ``type`` field. See > + :c:type:`v4l2_buf_type` for valid values. > + * - __u32 > + - ``reserved``\ [13] > + - A place holder for future extensions. Drivers and applications > + must set the array to zero. What should happen if you delete ALL buffers with this call? I.e., the equivalent to REQBUFS with count=0. Thinking about this the main difference is that DELETE_BUFS can only delete dequeued buffers and it does not stop streaming if all buffers are deleted. So REQBUFS with count=0 (or a STREAMOFF) is still needed to officially stop streaming and cancel the queue. Basically REQBUFS with count=0 is almost the equivalent of calling STREAMOFF followed by DELETE_BUFS for all buffers. Almost, but not quite: REQBUFS(0) also reports if the queue is unbalanced, and it sets q->num_buffers to 0. And in vb2_ioctl_reqbufs it will set vdev->queue->owner to NULL. I am inclined to do the same if DELETE_BUFS deletes all buffers. > + > +Return Value > +============ > + > +On success 0 is returned, on error -1 and the ``errno`` variable is set > +appropriately. The generic error codes are described at the > +:ref:`Generic Error Codes <gen-errors>` chapter. > + > +EBUSY > + File I/O is in progress. > + > +EINVAL > + The buffer ``index`` doesn't exist in the queue. > diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c > index dc7f6b59d237..9edb2a1e95fc 100644 > --- a/drivers/media/common/videobuf2/videobuf2-core.c > +++ b/drivers/media/common/videobuf2/videobuf2-core.c > @@ -1633,6 +1633,30 @@ int vb2_core_prepare_buf(struct vb2_queue *q, struct vb2_buffer *vb, void *pb) > } > EXPORT_SYMBOL_GPL(vb2_core_prepare_buf); > > +int vb2_core_delete_buf(struct vb2_queue *q, struct vb2_buffer *vb) > +{ > + mutex_lock(&q->mmap_lock); > + if (vb->planes[0].mem_priv) > + call_void_vb_qop(vb, buf_cleanup, vb); > + > + /* Free MMAP buffers or release USERPTR buffers */ > + if (q->memory == VB2_MEMORY_MMAP) > + __vb2_buf_mem_free(vb); > + else if (q->memory == VB2_MEMORY_DMABUF) > + __vb2_buf_dmabuf_put(vb); > + else > + __vb2_buf_userptr_put(vb); > + > + vb2_queue_remove_buffer(q, vb); > + mutex_unlock(&q->mmap_lock); > + > + dprintk(q, 2, "buffer %d deleted\n", vb->index); > + kfree(vb); > + > + return 0; > +} > +EXPORT_SYMBOL_GPL(vb2_core_delete_buf); This is duplicating what already happens in __vb2_free_mem and __vb2_queue_free. That code needs to be refactored. What you want is a __vb2_delete_buffers(struct vb2_queue *q, unsigned int index, unsigned int buffers) function that is called with mmap_lock held and that deletes buffers in the range 'index' to 'index + count - 1'. Buffers may already be deleted. __vb2_free_mem does almost do all of that already. Then this new function can be called from __vb2_queue_free() and you can make a vb2_core_delete_bufs() function that takes the lock and calls __vb2_delete_buffers. Another note: currently __vb2_queue_free checks if any of the buffers had unbalanced operations. That check needs to be moved to __vb2_delete_buffers as well otherwise that would never be reported when using DELETE_BUFS. > + > /* > * vb2_start_streaming() - Attempt to start streaming. > * @q: videobuf2 queue > diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c > index 8ba658ad9891..d0098f58a65c 100644 > --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c > +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c > @@ -385,7 +385,7 @@ static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct media_device *md > > vb = vb2_get_buffer(q, b->index); > if (!vb) { > - dprintk(q, 1, "%s: buffer is NULL\n", opname); > + dprintk(q, 1, "%s: buffer %u was deleted\n", opname, b->index); > return -EINVAL; > } > > @@ -757,6 +757,42 @@ int vb2_prepare_buf(struct vb2_queue *q, struct media_device *mdev, > } > EXPORT_SYMBOL_GPL(vb2_prepare_buf); > > +int vb2_delete_bufs(struct vb2_queue *q, struct v4l2_delete_buffers *d) > +{ > + struct vb2_buffer *vb; > + unsigned int index; > + int ret = 0; > + Add: if (!d->count) return 0; (possibly also check if !d->index) > + if (d->index > q->num_buffers || > should be >= here. > + d->count > q->num_buffers || > + (d->index + d->count) > q->num_buffers) { > + return -EINVAL; > + } Once we can delete buffers, how does that change the meaning of num_buffers? Isn't this really max_buffer_index or something similar? But we probably also still need to keep track of the actual number of buffers. And create_bufs still allocated buffers from the last index onwards, it does not attempt to reuse indices of previously deleted buffers. There are a lot of drivers that use num_buffers, they will have to be audited. This needs a lot more thought. > + > + for (index = d->index; index < d->index + d->count; index++) { > + vb = vb2_get_buffer(q, index); > + if (!vb) { > + dprintk(q, 1, "can't find the requested buffer\n"); > + ret = -EINVAL; > + goto error; > + } > + if (vb->state != VB2_BUF_STATE_DEQUEUED) { > + dprintk(q, 1, "can't delete non dequeued buffer index %d\n", vb->index); > + ret = -EINVAL; > + goto error; > + } These checks have to take place first, then, if all is OK, you call vb2_core_delete_bufs. Actually, thinking this over, I would move all these checks to vb2_core_delete_bufs. It can all be put under the mmap_lock mutex to ensure nobody is messing around with the queue while this takes place. Note that when vb2_core_reqbufs() is called with count=0, then if it sees that a buffer is still in use (mmaped), it will log a debug message that the buffers are orphaned. We should keep that, I believe. > + > + ret = vb2_core_delete_buf(q, vb); > + if (ret) > + break; > + } > + > +error: > + d->index = index; I wouldn't do this. I don't think this is useful. > + return ret; > +} > +EXPORT_SYMBOL_GPL(vb2_delete_bufs); > + > int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create) > { > unsigned requested_planes = 1; > diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c > index f81279492682..215654fd6581 100644 > --- a/drivers/media/v4l2-core/v4l2-dev.c > +++ b/drivers/media/v4l2-core/v4l2-dev.c > @@ -720,6 +720,7 @@ static void determine_valid_ioctls(struct video_device *vdev) > SET_VALID_IOCTL(ops, VIDIOC_PREPARE_BUF, vidioc_prepare_buf); > SET_VALID_IOCTL(ops, VIDIOC_STREAMON, vidioc_streamon); > SET_VALID_IOCTL(ops, VIDIOC_STREAMOFF, vidioc_streamoff); > + SET_VALID_IOCTL(ops, VIDIOC_DELETE_BUFS, vidioc_delete_bufs); > } > > if (is_vid || is_vbi || is_meta) { > diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c > index f4d9d6279094..aac3a0ea0126 100644 > --- a/drivers/media/v4l2-core/v4l2-ioctl.c > +++ b/drivers/media/v4l2-core/v4l2-ioctl.c > @@ -489,6 +489,13 @@ static void v4l_print_create_buffers(const void *arg, bool write_only) > v4l_print_format(&p->format, write_only); > } > > +static void v4l_print_delete_buffers(const void *arg, bool write_only) > +{ > + const struct v4l2_delete_buffers *p = arg; > + > + pr_cont("index=%d, count=%d\n", p->index, p->count); Use %u since both args are unsigned. > +} > + > static void v4l_print_streamparm(const void *arg, bool write_only) > { > const struct v4l2_streamparm *p = arg; > @@ -2160,6 +2167,15 @@ static int v4l_prepare_buf(const struct v4l2_ioctl_ops *ops, > return ret ? ret : ops->vidioc_prepare_buf(file, fh, b); > } > > +static int v4l_delete_bufs(const struct v4l2_ioctl_ops *ops, > + struct file *file, void *fh, void *arg) > +{ > + struct v4l2_delete_buffers *delete = arg; > + int ret = check_fmt(file, delete->type); > + > + return ret ? ret : ops->vidioc_delete_bufs(file, fh, delete); > +} > + > static int v4l_g_parm(const struct v4l2_ioctl_ops *ops, > struct file *file, void *fh, void *arg) > { > @@ -2909,6 +2925,7 @@ static const struct v4l2_ioctl_info v4l2_ioctls[] = { > IOCTL_INFO(VIDIOC_ENUM_FREQ_BANDS, v4l_enum_freq_bands, v4l_print_freq_band, 0), > IOCTL_INFO(VIDIOC_DBG_G_CHIP_INFO, v4l_dbg_g_chip_info, v4l_print_dbg_chip_info, INFO_FL_CLEAR(v4l2_dbg_chip_info, match)), > IOCTL_INFO(VIDIOC_QUERY_EXT_CTRL, v4l_query_ext_ctrl, v4l_print_query_ext_ctrl, INFO_FL_CTRL | INFO_FL_CLEAR(v4l2_query_ext_ctrl, id)), > + IOCTL_INFO(VIDIOC_DELETE_BUFS, v4l_delete_bufs, v4l_print_delete_buffers, INFO_FL_PRIO | INFO_FL_QUEUE | INFO_FL_CLEAR(v4l2_delete_buffers, type)), > }; > #define V4L2_IOCTLS ARRAY_SIZE(v4l2_ioctls) > > diff --git a/include/media/v4l2-ioctl.h b/include/media/v4l2-ioctl.h > index edb733f21604..55afbde54211 100644 > --- a/include/media/v4l2-ioctl.h > +++ b/include/media/v4l2-ioctl.h > @@ -163,6 +163,8 @@ struct v4l2_fh; > * :ref:`VIDIOC_CREATE_BUFS <vidioc_create_bufs>` ioctl > * @vidioc_prepare_buf: pointer to the function that implements > * :ref:`VIDIOC_PREPARE_BUF <vidioc_prepare_buf>` ioctl > + * @vidioc_delete_bufs: pointer to the function that implements > + * :ref:`VIDIOC_DELETE_BUFS <vidioc_delete_bufs>` ioctl > * @vidioc_overlay: pointer to the function that implements > * :ref:`VIDIOC_OVERLAY <vidioc_overlay>` ioctl > * @vidioc_g_fbuf: pointer to the function that implements > @@ -422,6 +424,8 @@ struct v4l2_ioctl_ops { > struct v4l2_create_buffers *b); > int (*vidioc_prepare_buf)(struct file *file, void *fh, > struct v4l2_buffer *b); > + int (*vidioc_delete_bufs)(struct file *file, void *fh, > + struct v4l2_delete_buffers *d); > > int (*vidioc_overlay)(struct file *file, void *fh, unsigned int i); > int (*vidioc_g_fbuf)(struct file *file, void *fh, > diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h > index 97153c69583f..e2c5ff31efd0 100644 > --- a/include/media/videobuf2-core.h > +++ b/include/media/videobuf2-core.h > @@ -843,6 +843,15 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory, > */ > int vb2_core_prepare_buf(struct vb2_queue *q, struct vb2_buffer *vb, void *pb); > > +/** > + * vb2_core_delete_buf() - > + * @q: pointer to &struct vb2_queue with videobuf2 queue. > + * @vb: pointer to struct &vb2_buffer. > + * > + * Return: returns zero on success; an error code otherwise. > + */ > +int vb2_core_delete_buf(struct vb2_queue *q, struct vb2_buffer *vb); > + > /** > * vb2_core_qbuf() - Queue a buffer from userspace > * > diff --git a/include/media/videobuf2-v4l2.h b/include/media/videobuf2-v4l2.h > index 5a845887850b..2ef68fdf388f 100644 > --- a/include/media/videobuf2-v4l2.h > +++ b/include/media/videobuf2-v4l2.h > @@ -118,6 +118,17 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create); > */ > int vb2_prepare_buf(struct vb2_queue *q, struct media_device *mdev, > struct v4l2_buffer *b); > +/** > + * vb2_delete_bufs() - Delete buffers from the queue > + * > + * @q: pointer to &struct vb2_queue with videobuf2 queue. > + * @d: delete parameter, passed from userspace to > + * &v4l2_ioctl_ops->vidioc_delete_bufs handler in driver > + * > + * The return values from this function are intended to be directly returned > + * from &v4l2_ioctl_ops->vidioc_delete_bufs handler in driver. > + */ > +int vb2_delete_bufs(struct vb2_queue *q, struct v4l2_delete_buffers *d); I'm missing the vb2_ioctl_delete_bufs function with a call to vb2_queue_is_busy(). > > /** > * vb2_qbuf() - Queue a buffer from userspace > diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h > index 78260e5d9985..9cc7f570d995 100644 > --- a/include/uapi/linux/videodev2.h > +++ b/include/uapi/linux/videodev2.h > @@ -2616,6 +2616,20 @@ struct v4l2_create_buffers { > __u32 reserved[6]; > }; > > +/** > + * struct v4l2_delete_buffers - VIDIOC_DELETE_BUFS argument > + * @index: the first buffer to be deleted > + * @count: number of buffers to delete > + * @type: enum v4l2_buf_type > + * @reserved: future extensions > + */ > +struct v4l2_delete_buffers { > + __u32 index; > + __u32 count; > + __u32 type; > + __u32 reserved[13]; > +}; > + > /* > * I O C T L C O D E S F O R V I D E O D E V I C E S > * > @@ -2715,6 +2729,8 @@ struct v4l2_create_buffers { > #define VIDIOC_DBG_G_CHIP_INFO _IOWR('V', 102, struct v4l2_dbg_chip_info) > > #define VIDIOC_QUERY_EXT_CTRL _IOWR('V', 103, struct v4l2_query_ext_ctrl) > +#define VIDIOC_DELETE_BUFS _IOWR('V', 104, struct v4l2_delete_buffers) > + > > /* Reminder: when adding new ioctls please add support for them to > drivers/media/v4l2-core/v4l2-compat-ioctl32.c as well! */ You need much more extensive compliance checks for this, esp. mixing create_bufs and delete_bufs. And test it with the test-media test script. Regards, Hans
On 05/09/2023 10:17, Hans Verkuil wrote: > > You need much more extensive compliance checks for this, esp. mixing > create_bufs and delete_bufs. And test it with the test-media test script. This also means that you need to add patches adding delete_bufs support to vivid, vim2m, vimc, vicodec, visl. That allows test-media together with v4l2-compliance to do a good job of regression testing this new ioctl. Regards, Hans
Le 05/09/2023 à 10:17, Hans Verkuil a écrit : > On 01/09/2023 14:44, Benjamin Gaignard wrote: >> VIDIOC_DELETE_BUFS ioctl allows to delete buffers from a queue. >> The number of buffers to delete in given by count field of >> struct v4l2_delete_buffers and the range start at the index >> specified in the same structure. >> >> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com> >> --- >> v6: >> - Add lock in vb2_core_delete_buf() >> - Fix typo and comments >> - Add flags in VIDIOC_DELETE_BUFS decalaration >> >> .../userspace-api/media/v4l/user-func.rst | 1 + >> .../media/v4l/vidioc-delete-bufs.rst | 73 +++++++++++++++++++ >> .../media/common/videobuf2/videobuf2-core.c | 24 ++++++ >> .../media/common/videobuf2/videobuf2-v4l2.c | 38 +++++++++- >> drivers/media/v4l2-core/v4l2-dev.c | 1 + >> drivers/media/v4l2-core/v4l2-ioctl.c | 17 +++++ >> include/media/v4l2-ioctl.h | 4 + >> include/media/videobuf2-core.h | 9 +++ >> include/media/videobuf2-v4l2.h | 11 +++ >> include/uapi/linux/videodev2.h | 16 ++++ >> 10 files changed, 193 insertions(+), 1 deletion(-) >> create mode 100644 Documentation/userspace-api/media/v4l/vidioc-delete-bufs.rst >> >> diff --git a/Documentation/userspace-api/media/v4l/user-func.rst b/Documentation/userspace-api/media/v4l/user-func.rst >> index 15ff0bf7bbe6..3fd567695477 100644 >> --- a/Documentation/userspace-api/media/v4l/user-func.rst >> +++ b/Documentation/userspace-api/media/v4l/user-func.rst >> @@ -17,6 +17,7 @@ Function Reference >> vidioc-dbg-g-chip-info >> vidioc-dbg-g-register >> vidioc-decoder-cmd >> + vidioc-delete-bufs >> vidioc-dqevent >> vidioc-dv-timings-cap >> vidioc-encoder-cmd >> diff --git a/Documentation/userspace-api/media/v4l/vidioc-delete-bufs.rst b/Documentation/userspace-api/media/v4l/vidioc-delete-bufs.rst >> new file mode 100644 >> index 000000000000..a55fe6331fc8 >> --- /dev/null >> +++ b/Documentation/userspace-api/media/v4l/vidioc-delete-bufs.rst >> @@ -0,0 +1,73 @@ >> +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later >> +.. c:namespace:: V4L >> + >> +.. _VIDIOC_DELETE_BUFS: >> + >> +************************ >> +ioctl VIDIOC_DELETE_BUFS >> +************************ >> + >> +Name >> +==== >> + >> +VIDIOC_DELETE_BUFS - Deletes buffers from a queue >> + >> +Synopsis >> +======== >> + >> +.. c:macro:: VIDIOC_DELETE_BUFs >> + >> +``int ioctl(int fd, VIDIOC_DELETE_BUFs, struct v4l2_delete_buffers *argp)`` >> + >> +Arguments >> +========= >> + >> +``fd`` >> + File descriptor returned by :c:func:`open()`. >> + >> +``argp`` >> + Pointer to struct :c:type:`v4l2_delete_buffers`. >> + >> +Description >> +=========== >> + >> +Applications can optionally call the :ref:`VIDIOC_DELETE_BUFS` ioctl to >> +delete buffers from a queue. >> + >> +.. c:type:: v4l2_delete_buffers >> + >> +.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.5cm}| >> + >> +.. flat-table:: struct v4l2_delete_buffers >> + :header-rows: 0 >> + :stub-columns: 0 >> + :widths: 1 1 2 >> + >> + * - __u32 >> + - ``index`` >> + - The starting buffer index to delete. >> + * - __u32 >> + - ``count`` >> + - The number of buffers to be deleted. > That's not quite correct. This function will delete the buffers with indices > index until index+count-1. And indices in that range have to be valid buffers, > i.e. you can't have already deleted buffers in that range. > > Or should we allow that? It is a fair question. > > All buffers also have to be in the DEQUEUED state. > > The text above suggests that given the following valid indices: > > 0, 1, 3, 4 (so the buffer with index 2 was already deleted) > > deleting 2 buffers from index 1 would delete buffers 1, 3. When in > fact it will attempt to delete buffers 1 and 2. > > Also document explicitly that calling this with count=0 (and perhaps > index=0 as well?) can be used to check if this ioctl is supported. I will do that. > >> + * - __u32 >> + - ``type`` >> + - Type of the stream or buffers, this is the same as the struct >> + :c:type:`v4l2_format` ``type`` field. See >> + :c:type:`v4l2_buf_type` for valid values. >> + * - __u32 >> + - ``reserved``\ [13] >> + - A place holder for future extensions. Drivers and applications >> + must set the array to zero. > What should happen if you delete ALL buffers with this call? I.e., the > equivalent to REQBUFS with count=0. > > Thinking about this the main difference is that DELETE_BUFS can only delete > dequeued buffers and it does not stop streaming if all buffers are deleted. > > So REQBUFS with count=0 (or a STREAMOFF) is still needed to officially stop > streaming and cancel the queue. > > Basically REQBUFS with count=0 is almost the equivalent of calling STREAMOFF followed > by DELETE_BUFS for all buffers. Almost, but not quite: REQBUFS(0) also reports > if the queue is unbalanced, and it sets q->num_buffers to 0. And in vb2_ioctl_reqbufs > it will set vdev->queue->owner to NULL. > > I am inclined to do the same if DELETE_BUFS deletes all buffers. Unlike REQBUFS DELETE_BUFS can delete buffers while streaming so for me the ownership should not change even if there is no more dequeued buffers. For REQBUFS with count=0 means that the going stream is stopped so we can delete all the buffers while DELETE_BUFS usage is to delete buffers while keeping the stream alive. > >> + >> +Return Value >> +============ >> + >> +On success 0 is returned, on error -1 and the ``errno`` variable is set >> +appropriately. The generic error codes are described at the >> +:ref:`Generic Error Codes <gen-errors>` chapter. >> + >> +EBUSY >> + File I/O is in progress. >> + >> +EINVAL >> + The buffer ``index`` doesn't exist in the queue. >> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c >> index dc7f6b59d237..9edb2a1e95fc 100644 >> --- a/drivers/media/common/videobuf2/videobuf2-core.c >> +++ b/drivers/media/common/videobuf2/videobuf2-core.c >> @@ -1633,6 +1633,30 @@ int vb2_core_prepare_buf(struct vb2_queue *q, struct vb2_buffer *vb, void *pb) >> } >> EXPORT_SYMBOL_GPL(vb2_core_prepare_buf); >> >> +int vb2_core_delete_buf(struct vb2_queue *q, struct vb2_buffer *vb) >> +{ >> + mutex_lock(&q->mmap_lock); >> + if (vb->planes[0].mem_priv) >> + call_void_vb_qop(vb, buf_cleanup, vb); >> + >> + /* Free MMAP buffers or release USERPTR buffers */ >> + if (q->memory == VB2_MEMORY_MMAP) >> + __vb2_buf_mem_free(vb); >> + else if (q->memory == VB2_MEMORY_DMABUF) >> + __vb2_buf_dmabuf_put(vb); >> + else >> + __vb2_buf_userptr_put(vb); >> + >> + vb2_queue_remove_buffer(q, vb); >> + mutex_unlock(&q->mmap_lock); >> + >> + dprintk(q, 2, "buffer %d deleted\n", vb->index); >> + kfree(vb); >> + >> + return 0; >> +} >> +EXPORT_SYMBOL_GPL(vb2_core_delete_buf); > This is duplicating what already happens in __vb2_free_mem and __vb2_queue_free. > > That code needs to be refactored. > > What you want is a __vb2_delete_buffers(struct vb2_queue *q, unsigned int index, unsigned int buffers) > function that is called with mmap_lock held and that deletes buffers in the range 'index' > to 'index + count - 1'. Buffers may already be deleted. > > __vb2_free_mem does almost do all of that already. > > Then this new function can be called from __vb2_queue_free() and you can make > a vb2_core_delete_bufs() function that takes the lock and calls __vb2_delete_buffers. > > Another note: currently __vb2_queue_free checks if any of the buffers had unbalanced > operations. That check needs to be moved to __vb2_delete_buffers as well otherwise > that would never be reported when using DELETE_BUFS. Loops in __vb2_queue_free() and __vb2_free_mem() try to delete buffers at the end of the queue, I could just modify these functions prototype and loops to start from a given index. That should do the job but have impact on create_bufs (see below) > >> + >> /* >> * vb2_start_streaming() - Attempt to start streaming. >> * @q: videobuf2 queue >> diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c >> index 8ba658ad9891..d0098f58a65c 100644 >> --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c >> +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c >> @@ -385,7 +385,7 @@ static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct media_device *md >> >> vb = vb2_get_buffer(q, b->index); >> if (!vb) { >> - dprintk(q, 1, "%s: buffer is NULL\n", opname); >> + dprintk(q, 1, "%s: buffer %u was deleted\n", opname, b->index); >> return -EINVAL; >> } >> >> @@ -757,6 +757,42 @@ int vb2_prepare_buf(struct vb2_queue *q, struct media_device *mdev, >> } >> EXPORT_SYMBOL_GPL(vb2_prepare_buf); >> >> +int vb2_delete_bufs(struct vb2_queue *q, struct v4l2_delete_buffers *d) >> +{ >> + struct vb2_buffer *vb; >> + unsigned int index; >> + int ret = 0; >> + > Add: > > if (!d->count) > return 0; > > (possibly also check if !d->index) > >> + if (d->index > q->num_buffers || >> should be >= here. >> + d->count > q->num_buffers || >> + (d->index + d->count) > q->num_buffers) { >> + return -EINVAL; >> + } > Once we can delete buffers, how does that change the meaning of num_buffers? > Isn't this really max_buffer_index or something similar? But we probably also > still need to keep track of the actual number of buffers. > > And create_bufs still allocated buffers from the last index onwards, it does > not attempt to reuse indices of previously deleted buffers. Reuse previous indices require to be sure that a range of index is free because create_bufs returns, in index parameter, the starting buffer index. I will add a function to find the first available range and use it in vb2_create_bufs() to change how create->index is set. Hans, sound good for you ? > > There are a lot of drivers that use num_buffers, they will have to be audited. > > This needs a lot more thought. > >> + >> + for (index = d->index; index < d->index + d->count; index++) { >> + vb = vb2_get_buffer(q, index); >> + if (!vb) { >> + dprintk(q, 1, "can't find the requested buffer\n"); >> + ret = -EINVAL; >> + goto error; >> + } >> + if (vb->state != VB2_BUF_STATE_DEQUEUED) { >> + dprintk(q, 1, "can't delete non dequeued buffer index %d\n", vb->index); >> + ret = -EINVAL; >> + goto error; >> + } > These checks have to take place first, then, if all is OK, you call vb2_core_delete_bufs. > > Actually, thinking this over, I would move all these checks to vb2_core_delete_bufs. > > It can all be put under the mmap_lock mutex to ensure nobody is messing around > with the queue while this takes place. > > Note that when vb2_core_reqbufs() is called with count=0, then if it sees that > a buffer is still in use (mmaped), it will log a debug message that the buffers > are orphaned. We should keep that, I believe. > >> + >> + ret = vb2_core_delete_buf(q, vb); >> + if (ret) >> + break; >> + } >> + >> +error: >> + d->index = index; > I wouldn't do this. I don't think this is useful. > >> + return ret; >> +} >> +EXPORT_SYMBOL_GPL(vb2_delete_bufs); >> + >> int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create) >> { >> unsigned requested_planes = 1; >> diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c >> index f81279492682..215654fd6581 100644 >> --- a/drivers/media/v4l2-core/v4l2-dev.c >> +++ b/drivers/media/v4l2-core/v4l2-dev.c >> @@ -720,6 +720,7 @@ static void determine_valid_ioctls(struct video_device *vdev) >> SET_VALID_IOCTL(ops, VIDIOC_PREPARE_BUF, vidioc_prepare_buf); >> SET_VALID_IOCTL(ops, VIDIOC_STREAMON, vidioc_streamon); >> SET_VALID_IOCTL(ops, VIDIOC_STREAMOFF, vidioc_streamoff); >> + SET_VALID_IOCTL(ops, VIDIOC_DELETE_BUFS, vidioc_delete_bufs); >> } >> >> if (is_vid || is_vbi || is_meta) { >> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c >> index f4d9d6279094..aac3a0ea0126 100644 >> --- a/drivers/media/v4l2-core/v4l2-ioctl.c >> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c >> @@ -489,6 +489,13 @@ static void v4l_print_create_buffers(const void *arg, bool write_only) >> v4l_print_format(&p->format, write_only); >> } >> >> +static void v4l_print_delete_buffers(const void *arg, bool write_only) >> +{ >> + const struct v4l2_delete_buffers *p = arg; >> + >> + pr_cont("index=%d, count=%d\n", p->index, p->count); > Use %u since both args are unsigned. > >> +} >> + >> static void v4l_print_streamparm(const void *arg, bool write_only) >> { >> const struct v4l2_streamparm *p = arg; >> @@ -2160,6 +2167,15 @@ static int v4l_prepare_buf(const struct v4l2_ioctl_ops *ops, >> return ret ? ret : ops->vidioc_prepare_buf(file, fh, b); >> } >> >> +static int v4l_delete_bufs(const struct v4l2_ioctl_ops *ops, >> + struct file *file, void *fh, void *arg) >> +{ >> + struct v4l2_delete_buffers *delete = arg; >> + int ret = check_fmt(file, delete->type); >> + >> + return ret ? ret : ops->vidioc_delete_bufs(file, fh, delete); >> +} >> + >> static int v4l_g_parm(const struct v4l2_ioctl_ops *ops, >> struct file *file, void *fh, void *arg) >> { >> @@ -2909,6 +2925,7 @@ static const struct v4l2_ioctl_info v4l2_ioctls[] = { >> IOCTL_INFO(VIDIOC_ENUM_FREQ_BANDS, v4l_enum_freq_bands, v4l_print_freq_band, 0), >> IOCTL_INFO(VIDIOC_DBG_G_CHIP_INFO, v4l_dbg_g_chip_info, v4l_print_dbg_chip_info, INFO_FL_CLEAR(v4l2_dbg_chip_info, match)), >> IOCTL_INFO(VIDIOC_QUERY_EXT_CTRL, v4l_query_ext_ctrl, v4l_print_query_ext_ctrl, INFO_FL_CTRL | INFO_FL_CLEAR(v4l2_query_ext_ctrl, id)), >> + IOCTL_INFO(VIDIOC_DELETE_BUFS, v4l_delete_bufs, v4l_print_delete_buffers, INFO_FL_PRIO | INFO_FL_QUEUE | INFO_FL_CLEAR(v4l2_delete_buffers, type)), >> }; >> #define V4L2_IOCTLS ARRAY_SIZE(v4l2_ioctls) >> >> diff --git a/include/media/v4l2-ioctl.h b/include/media/v4l2-ioctl.h >> index edb733f21604..55afbde54211 100644 >> --- a/include/media/v4l2-ioctl.h >> +++ b/include/media/v4l2-ioctl.h >> @@ -163,6 +163,8 @@ struct v4l2_fh; >> * :ref:`VIDIOC_CREATE_BUFS <vidioc_create_bufs>` ioctl >> * @vidioc_prepare_buf: pointer to the function that implements >> * :ref:`VIDIOC_PREPARE_BUF <vidioc_prepare_buf>` ioctl >> + * @vidioc_delete_bufs: pointer to the function that implements >> + * :ref:`VIDIOC_DELETE_BUFS <vidioc_delete_bufs>` ioctl >> * @vidioc_overlay: pointer to the function that implements >> * :ref:`VIDIOC_OVERLAY <vidioc_overlay>` ioctl >> * @vidioc_g_fbuf: pointer to the function that implements >> @@ -422,6 +424,8 @@ struct v4l2_ioctl_ops { >> struct v4l2_create_buffers *b); >> int (*vidioc_prepare_buf)(struct file *file, void *fh, >> struct v4l2_buffer *b); >> + int (*vidioc_delete_bufs)(struct file *file, void *fh, >> + struct v4l2_delete_buffers *d); >> >> int (*vidioc_overlay)(struct file *file, void *fh, unsigned int i); >> int (*vidioc_g_fbuf)(struct file *file, void *fh, >> diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h >> index 97153c69583f..e2c5ff31efd0 100644 >> --- a/include/media/videobuf2-core.h >> +++ b/include/media/videobuf2-core.h >> @@ -843,6 +843,15 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory, >> */ >> int vb2_core_prepare_buf(struct vb2_queue *q, struct vb2_buffer *vb, void *pb); >> >> +/** >> + * vb2_core_delete_buf() - >> + * @q: pointer to &struct vb2_queue with videobuf2 queue. >> + * @vb: pointer to struct &vb2_buffer. >> + * >> + * Return: returns zero on success; an error code otherwise. >> + */ >> +int vb2_core_delete_buf(struct vb2_queue *q, struct vb2_buffer *vb); >> + >> /** >> * vb2_core_qbuf() - Queue a buffer from userspace >> * >> diff --git a/include/media/videobuf2-v4l2.h b/include/media/videobuf2-v4l2.h >> index 5a845887850b..2ef68fdf388f 100644 >> --- a/include/media/videobuf2-v4l2.h >> +++ b/include/media/videobuf2-v4l2.h >> @@ -118,6 +118,17 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create); >> */ >> int vb2_prepare_buf(struct vb2_queue *q, struct media_device *mdev, >> struct v4l2_buffer *b); >> +/** >> + * vb2_delete_bufs() - Delete buffers from the queue >> + * >> + * @q: pointer to &struct vb2_queue with videobuf2 queue. >> + * @d: delete parameter, passed from userspace to >> + * &v4l2_ioctl_ops->vidioc_delete_bufs handler in driver >> + * >> + * The return values from this function are intended to be directly returned >> + * from &v4l2_ioctl_ops->vidioc_delete_bufs handler in driver. >> + */ >> +int vb2_delete_bufs(struct vb2_queue *q, struct v4l2_delete_buffers *d); > I'm missing the vb2_ioctl_delete_bufs function with a call to vb2_queue_is_busy(). > >> >> /** >> * vb2_qbuf() - Queue a buffer from userspace >> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h >> index 78260e5d9985..9cc7f570d995 100644 >> --- a/include/uapi/linux/videodev2.h >> +++ b/include/uapi/linux/videodev2.h >> @@ -2616,6 +2616,20 @@ struct v4l2_create_buffers { >> __u32 reserved[6]; >> }; >> >> +/** >> + * struct v4l2_delete_buffers - VIDIOC_DELETE_BUFS argument >> + * @index: the first buffer to be deleted >> + * @count: number of buffers to delete >> + * @type: enum v4l2_buf_type >> + * @reserved: future extensions >> + */ >> +struct v4l2_delete_buffers { >> + __u32 index; >> + __u32 count; >> + __u32 type; >> + __u32 reserved[13]; >> +}; >> + >> /* >> * I O C T L C O D E S F O R V I D E O D E V I C E S >> * >> @@ -2715,6 +2729,8 @@ struct v4l2_create_buffers { >> #define VIDIOC_DBG_G_CHIP_INFO _IOWR('V', 102, struct v4l2_dbg_chip_info) >> >> #define VIDIOC_QUERY_EXT_CTRL _IOWR('V', 103, struct v4l2_query_ext_ctrl) >> +#define VIDIOC_DELETE_BUFS _IOWR('V', 104, struct v4l2_delete_buffers) >> + >> >> /* Reminder: when adding new ioctls please add support for them to >> drivers/media/v4l2-core/v4l2-compat-ioctl32.c as well! */ > You need much more extensive compliance checks for this, esp. mixing > create_bufs and delete_bufs. And test it with the test-media test script. > > Regards, > > Hans >
Hi Benjamin, On 05/09/2023 16:28, Benjamin Gaignard wrote: > > Le 05/09/2023 à 10:17, Hans Verkuil a écrit : >> On 01/09/2023 14:44, Benjamin Gaignard wrote: >>> VIDIOC_DELETE_BUFS ioctl allows to delete buffers from a queue. >>> The number of buffers to delete in given by count field of >>> struct v4l2_delete_buffers and the range start at the index >>> specified in the same structure. >>> >>> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com> >>> --- >>> v6: >>> - Add lock in vb2_core_delete_buf() >>> - Fix typo and comments >>> - Add flags in VIDIOC_DELETE_BUFS decalaration >>> >>> .../userspace-api/media/v4l/user-func.rst | 1 + >>> .../media/v4l/vidioc-delete-bufs.rst | 73 +++++++++++++++++++ >>> .../media/common/videobuf2/videobuf2-core.c | 24 ++++++ >>> .../media/common/videobuf2/videobuf2-v4l2.c | 38 +++++++++- >>> drivers/media/v4l2-core/v4l2-dev.c | 1 + >>> drivers/media/v4l2-core/v4l2-ioctl.c | 17 +++++ >>> include/media/v4l2-ioctl.h | 4 + >>> include/media/videobuf2-core.h | 9 +++ >>> include/media/videobuf2-v4l2.h | 11 +++ >>> include/uapi/linux/videodev2.h | 16 ++++ >>> 10 files changed, 193 insertions(+), 1 deletion(-) >>> create mode 100644 Documentation/userspace-api/media/v4l/vidioc-delete-bufs.rst >>> >>> diff --git a/Documentation/userspace-api/media/v4l/user-func.rst b/Documentation/userspace-api/media/v4l/user-func.rst >>> index 15ff0bf7bbe6..3fd567695477 100644 >>> --- a/Documentation/userspace-api/media/v4l/user-func.rst >>> +++ b/Documentation/userspace-api/media/v4l/user-func.rst >>> @@ -17,6 +17,7 @@ Function Reference >>> vidioc-dbg-g-chip-info >>> vidioc-dbg-g-register >>> vidioc-decoder-cmd >>> + vidioc-delete-bufs >>> vidioc-dqevent >>> vidioc-dv-timings-cap >>> vidioc-encoder-cmd >>> diff --git a/Documentation/userspace-api/media/v4l/vidioc-delete-bufs.rst b/Documentation/userspace-api/media/v4l/vidioc-delete-bufs.rst >>> new file mode 100644 >>> index 000000000000..a55fe6331fc8 >>> --- /dev/null >>> +++ b/Documentation/userspace-api/media/v4l/vidioc-delete-bufs.rst >>> @@ -0,0 +1,73 @@ >>> +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later >>> +.. c:namespace:: V4L >>> + >>> +.. _VIDIOC_DELETE_BUFS: >>> + >>> +************************ >>> +ioctl VIDIOC_DELETE_BUFS >>> +************************ >>> + >>> +Name >>> +==== >>> + >>> +VIDIOC_DELETE_BUFS - Deletes buffers from a queue >>> + >>> +Synopsis >>> +======== >>> + >>> +.. c:macro:: VIDIOC_DELETE_BUFs >>> + >>> +``int ioctl(int fd, VIDIOC_DELETE_BUFs, struct v4l2_delete_buffers *argp)`` >>> + >>> +Arguments >>> +========= >>> + >>> +``fd`` >>> + File descriptor returned by :c:func:`open()`. >>> + >>> +``argp`` >>> + Pointer to struct :c:type:`v4l2_delete_buffers`. >>> + >>> +Description >>> +=========== >>> + >>> +Applications can optionally call the :ref:`VIDIOC_DELETE_BUFS` ioctl to >>> +delete buffers from a queue. >>> + >>> +.. c:type:: v4l2_delete_buffers >>> + >>> +.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.5cm}| >>> + >>> +.. flat-table:: struct v4l2_delete_buffers >>> + :header-rows: 0 >>> + :stub-columns: 0 >>> + :widths: 1 1 2 >>> + >>> + * - __u32 >>> + - ``index`` >>> + - The starting buffer index to delete. >>> + * - __u32 >>> + - ``count`` >>> + - The number of buffers to be deleted. >> That's not quite correct. This function will delete the buffers with indices >> index until index+count-1. And indices in that range have to be valid buffers, >> i.e. you can't have already deleted buffers in that range. >> >> Or should we allow that? It is a fair question. >> >> All buffers also have to be in the DEQUEUED state. >> >> The text above suggests that given the following valid indices: >> >> 0, 1, 3, 4 (so the buffer with index 2 was already deleted) >> >> deleting 2 buffers from index 1 would delete buffers 1, 3. When in >> fact it will attempt to delete buffers 1 and 2. >> >> Also document explicitly that calling this with count=0 (and perhaps >> index=0 as well?) can be used to check if this ioctl is supported. > > I will do that. > >> >>> + * - __u32 >>> + - ``type`` >>> + - Type of the stream or buffers, this is the same as the struct >>> + :c:type:`v4l2_format` ``type`` field. See >>> + :c:type:`v4l2_buf_type` for valid values. >>> + * - __u32 >>> + - ``reserved``\ [13] >>> + - A place holder for future extensions. Drivers and applications >>> + must set the array to zero. >> What should happen if you delete ALL buffers with this call? I.e., the >> equivalent to REQBUFS with count=0. >> >> Thinking about this the main difference is that DELETE_BUFS can only delete >> dequeued buffers and it does not stop streaming if all buffers are deleted. >> >> So REQBUFS with count=0 (or a STREAMOFF) is still needed to officially stop >> streaming and cancel the queue. >> >> Basically REQBUFS with count=0 is almost the equivalent of calling STREAMOFF followed >> by DELETE_BUFS for all buffers. Almost, but not quite: REQBUFS(0) also reports >> if the queue is unbalanced, and it sets q->num_buffers to 0. And in vb2_ioctl_reqbufs >> it will set vdev->queue->owner to NULL. >> >> I am inclined to do the same if DELETE_BUFS deletes all buffers. > > Unlike REQBUFS DELETE_BUFS can delete buffers while streaming so for me the ownership > should not change even if there is no more dequeued buffers. > For REQBUFS with count=0 means that the going stream is stopped so we can delete all the buffers > while DELETE_BUFS usage is to delete buffers while keeping the stream alive. I'm undecided on this. It's something we can decide later. > >> >>> + >>> +Return Value >>> +============ >>> + >>> +On success 0 is returned, on error -1 and the ``errno`` variable is set >>> +appropriately. The generic error codes are described at the >>> +:ref:`Generic Error Codes <gen-errors>` chapter. >>> + >>> +EBUSY >>> + File I/O is in progress. >>> + >>> +EINVAL >>> + The buffer ``index`` doesn't exist in the queue. >>> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c >>> index dc7f6b59d237..9edb2a1e95fc 100644 >>> --- a/drivers/media/common/videobuf2/videobuf2-core.c >>> +++ b/drivers/media/common/videobuf2/videobuf2-core.c >>> @@ -1633,6 +1633,30 @@ int vb2_core_prepare_buf(struct vb2_queue *q, struct vb2_buffer *vb, void *pb) >>> } >>> EXPORT_SYMBOL_GPL(vb2_core_prepare_buf); >>> +int vb2_core_delete_buf(struct vb2_queue *q, struct vb2_buffer *vb) >>> +{ >>> + mutex_lock(&q->mmap_lock); >>> + if (vb->planes[0].mem_priv) >>> + call_void_vb_qop(vb, buf_cleanup, vb); >>> + >>> + /* Free MMAP buffers or release USERPTR buffers */ >>> + if (q->memory == VB2_MEMORY_MMAP) >>> + __vb2_buf_mem_free(vb); >>> + else if (q->memory == VB2_MEMORY_DMABUF) >>> + __vb2_buf_dmabuf_put(vb); >>> + else >>> + __vb2_buf_userptr_put(vb); >>> + >>> + vb2_queue_remove_buffer(q, vb); >>> + mutex_unlock(&q->mmap_lock); >>> + >>> + dprintk(q, 2, "buffer %d deleted\n", vb->index); >>> + kfree(vb); >>> + >>> + return 0; >>> +} >>> +EXPORT_SYMBOL_GPL(vb2_core_delete_buf); >> This is duplicating what already happens in __vb2_free_mem and __vb2_queue_free. >> >> That code needs to be refactored. >> >> What you want is a __vb2_delete_buffers(struct vb2_queue *q, unsigned int index, unsigned int buffers) >> function that is called with mmap_lock held and that deletes buffers in the range 'index' >> to 'index + count - 1'. Buffers may already be deleted. >> >> __vb2_free_mem does almost do all of that already. >> >> Then this new function can be called from __vb2_queue_free() and you can make >> a vb2_core_delete_bufs() function that takes the lock and calls __vb2_delete_buffers. >> >> Another note: currently __vb2_queue_free checks if any of the buffers had unbalanced >> operations. That check needs to be moved to __vb2_delete_buffers as well otherwise >> that would never be reported when using DELETE_BUFS. > > Loops in __vb2_queue_free() and __vb2_free_mem() try to delete buffers at the end of the > queue, I could just modify these functions prototype and loops to start from a given index. > That should do the job but have impact on create_bufs (see below) > >> >>> + >>> /* >>> * vb2_start_streaming() - Attempt to start streaming. >>> * @q: videobuf2 queue >>> diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c >>> index 8ba658ad9891..d0098f58a65c 100644 >>> --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c >>> +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c >>> @@ -385,7 +385,7 @@ static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct media_device *md >>> vb = vb2_get_buffer(q, b->index); >>> if (!vb) { >>> - dprintk(q, 1, "%s: buffer is NULL\n", opname); >>> + dprintk(q, 1, "%s: buffer %u was deleted\n", opname, b->index); >>> return -EINVAL; >>> } >>> @@ -757,6 +757,42 @@ int vb2_prepare_buf(struct vb2_queue *q, struct media_device *mdev, >>> } >>> EXPORT_SYMBOL_GPL(vb2_prepare_buf); >>> +int vb2_delete_bufs(struct vb2_queue *q, struct v4l2_delete_buffers *d) >>> +{ >>> + struct vb2_buffer *vb; >>> + unsigned int index; >>> + int ret = 0; >>> + >> Add: >> >> if (!d->count) >> return 0; >> >> (possibly also check if !d->index) >> >>> + if (d->index > q->num_buffers || >>> should be >= here. >>> + d->count > q->num_buffers || >>> + (d->index + d->count) > q->num_buffers) { >>> + return -EINVAL; >>> + } >> Once we can delete buffers, how does that change the meaning of num_buffers? >> Isn't this really max_buffer_index or something similar? But we probably also >> still need to keep track of the actual number of buffers. >> >> And create_bufs still allocated buffers from the last index onwards, it does >> not attempt to reuse indices of previously deleted buffers. > > Reuse previous indices require to be sure that a range of index is free because > create_bufs returns, in index parameter, the starting buffer index. > I will add a function to find the first available range and use it in vb2_create_bufs() > to change how create->index is set. > Hans, sound good for you ? That's what I had in mind. It is an option to keep a bitmap to keep track of which buffer indices are in use. You could use bitmap_find_next_zero_area to find the free range. Just an option. > >> >> There are a lot of drivers that use num_buffers, they will have to be audited. >> >> This needs a lot more thought. >> >>> + >>> + for (index = d->index; index < d->index + d->count; index++) { >>> + vb = vb2_get_buffer(q, index); >>> + if (!vb) { >>> + dprintk(q, 1, "can't find the requested buffer\n"); >>> + ret = -EINVAL; >>> + goto error; >>> + } >>> + if (vb->state != VB2_BUF_STATE_DEQUEUED) { >>> + dprintk(q, 1, "can't delete non dequeued buffer index %d\n", vb->index); >>> + ret = -EINVAL; >>> + goto error; >>> + } >> These checks have to take place first, then, if all is OK, you call vb2_core_delete_bufs. >> >> Actually, thinking this over, I would move all these checks to vb2_core_delete_bufs. >> >> It can all be put under the mmap_lock mutex to ensure nobody is messing around >> with the queue while this takes place. >> >> Note that when vb2_core_reqbufs() is called with count=0, then if it sees that >> a buffer is still in use (mmaped), it will log a debug message that the buffers >> are orphaned. We should keep that, I believe. >> >>> + >>> + ret = vb2_core_delete_buf(q, vb); >>> + if (ret) >>> + break; >>> + } >>> + >>> +error: >>> + d->index = index; >> I wouldn't do this. I don't think this is useful. >> >>> + return ret; >>> +} >>> +EXPORT_SYMBOL_GPL(vb2_delete_bufs); >>> + >>> int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create) >>> { >>> unsigned requested_planes = 1; >>> diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c >>> index f81279492682..215654fd6581 100644 >>> --- a/drivers/media/v4l2-core/v4l2-dev.c >>> +++ b/drivers/media/v4l2-core/v4l2-dev.c >>> @@ -720,6 +720,7 @@ static void determine_valid_ioctls(struct video_device *vdev) >>> SET_VALID_IOCTL(ops, VIDIOC_PREPARE_BUF, vidioc_prepare_buf); >>> SET_VALID_IOCTL(ops, VIDIOC_STREAMON, vidioc_streamon); >>> SET_VALID_IOCTL(ops, VIDIOC_STREAMOFF, vidioc_streamoff); >>> + SET_VALID_IOCTL(ops, VIDIOC_DELETE_BUFS, vidioc_delete_bufs); >>> } >>> if (is_vid || is_vbi || is_meta) { >>> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c >>> index f4d9d6279094..aac3a0ea0126 100644 >>> --- a/drivers/media/v4l2-core/v4l2-ioctl.c >>> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c >>> @@ -489,6 +489,13 @@ static void v4l_print_create_buffers(const void *arg, bool write_only) >>> v4l_print_format(&p->format, write_only); >>> } >>> +static void v4l_print_delete_buffers(const void *arg, bool write_only) >>> +{ >>> + const struct v4l2_delete_buffers *p = arg; >>> + >>> + pr_cont("index=%d, count=%d\n", p->index, p->count); >> Use %u since both args are unsigned. >> >>> +} >>> + >>> static void v4l_print_streamparm(const void *arg, bool write_only) >>> { >>> const struct v4l2_streamparm *p = arg; >>> @@ -2160,6 +2167,15 @@ static int v4l_prepare_buf(const struct v4l2_ioctl_ops *ops, >>> return ret ? ret : ops->vidioc_prepare_buf(file, fh, b); >>> } >>> +static int v4l_delete_bufs(const struct v4l2_ioctl_ops *ops, >>> + struct file *file, void *fh, void *arg) >>> +{ >>> + struct v4l2_delete_buffers *delete = arg; >>> + int ret = check_fmt(file, delete->type); >>> + >>> + return ret ? ret : ops->vidioc_delete_bufs(file, fh, delete); >>> +} >>> + >>> static int v4l_g_parm(const struct v4l2_ioctl_ops *ops, >>> struct file *file, void *fh, void *arg) >>> { >>> @@ -2909,6 +2925,7 @@ static const struct v4l2_ioctl_info v4l2_ioctls[] = { >>> IOCTL_INFO(VIDIOC_ENUM_FREQ_BANDS, v4l_enum_freq_bands, v4l_print_freq_band, 0), >>> IOCTL_INFO(VIDIOC_DBG_G_CHIP_INFO, v4l_dbg_g_chip_info, v4l_print_dbg_chip_info, INFO_FL_CLEAR(v4l2_dbg_chip_info, match)), >>> IOCTL_INFO(VIDIOC_QUERY_EXT_CTRL, v4l_query_ext_ctrl, v4l_print_query_ext_ctrl, INFO_FL_CTRL | INFO_FL_CLEAR(v4l2_query_ext_ctrl, id)), >>> + IOCTL_INFO(VIDIOC_DELETE_BUFS, v4l_delete_bufs, v4l_print_delete_buffers, INFO_FL_PRIO | INFO_FL_QUEUE | INFO_FL_CLEAR(v4l2_delete_buffers, type)), >>> }; >>> #define V4L2_IOCTLS ARRAY_SIZE(v4l2_ioctls) >>> diff --git a/include/media/v4l2-ioctl.h b/include/media/v4l2-ioctl.h >>> index edb733f21604..55afbde54211 100644 >>> --- a/include/media/v4l2-ioctl.h >>> +++ b/include/media/v4l2-ioctl.h >>> @@ -163,6 +163,8 @@ struct v4l2_fh; >>> * :ref:`VIDIOC_CREATE_BUFS <vidioc_create_bufs>` ioctl >>> * @vidioc_prepare_buf: pointer to the function that implements >>> * :ref:`VIDIOC_PREPARE_BUF <vidioc_prepare_buf>` ioctl >>> + * @vidioc_delete_bufs: pointer to the function that implements >>> + * :ref:`VIDIOC_DELETE_BUFS <vidioc_delete_bufs>` ioctl >>> * @vidioc_overlay: pointer to the function that implements >>> * :ref:`VIDIOC_OVERLAY <vidioc_overlay>` ioctl >>> * @vidioc_g_fbuf: pointer to the function that implements >>> @@ -422,6 +424,8 @@ struct v4l2_ioctl_ops { >>> struct v4l2_create_buffers *b); >>> int (*vidioc_prepare_buf)(struct file *file, void *fh, >>> struct v4l2_buffer *b); >>> + int (*vidioc_delete_bufs)(struct file *file, void *fh, >>> + struct v4l2_delete_buffers *d); >>> int (*vidioc_overlay)(struct file *file, void *fh, unsigned int i); >>> int (*vidioc_g_fbuf)(struct file *file, void *fh, >>> diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h >>> index 97153c69583f..e2c5ff31efd0 100644 >>> --- a/include/media/videobuf2-core.h >>> +++ b/include/media/videobuf2-core.h >>> @@ -843,6 +843,15 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory, >>> */ >>> int vb2_core_prepare_buf(struct vb2_queue *q, struct vb2_buffer *vb, void *pb); >>> +/** >>> + * vb2_core_delete_buf() - >>> + * @q: pointer to &struct vb2_queue with videobuf2 queue. >>> + * @vb: pointer to struct &vb2_buffer. >>> + * >>> + * Return: returns zero on success; an error code otherwise. >>> + */ >>> +int vb2_core_delete_buf(struct vb2_queue *q, struct vb2_buffer *vb); >>> + >>> /** >>> * vb2_core_qbuf() - Queue a buffer from userspace >>> * >>> diff --git a/include/media/videobuf2-v4l2.h b/include/media/videobuf2-v4l2.h >>> index 5a845887850b..2ef68fdf388f 100644 >>> --- a/include/media/videobuf2-v4l2.h >>> +++ b/include/media/videobuf2-v4l2.h >>> @@ -118,6 +118,17 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create); >>> */ >>> int vb2_prepare_buf(struct vb2_queue *q, struct media_device *mdev, >>> struct v4l2_buffer *b); >>> +/** >>> + * vb2_delete_bufs() - Delete buffers from the queue >>> + * >>> + * @q: pointer to &struct vb2_queue with videobuf2 queue. >>> + * @d: delete parameter, passed from userspace to >>> + * &v4l2_ioctl_ops->vidioc_delete_bufs handler in driver >>> + * >>> + * The return values from this function are intended to be directly returned >>> + * from &v4l2_ioctl_ops->vidioc_delete_bufs handler in driver. >>> + */ >>> +int vb2_delete_bufs(struct vb2_queue *q, struct v4l2_delete_buffers *d); >> I'm missing the vb2_ioctl_delete_bufs function with a call to vb2_queue_is_busy(). >> >>> /** >>> * vb2_qbuf() - Queue a buffer from userspace >>> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h >>> index 78260e5d9985..9cc7f570d995 100644 >>> --- a/include/uapi/linux/videodev2.h >>> +++ b/include/uapi/linux/videodev2.h >>> @@ -2616,6 +2616,20 @@ struct v4l2_create_buffers { >>> __u32 reserved[6]; >>> }; >>> +/** >>> + * struct v4l2_delete_buffers - VIDIOC_DELETE_BUFS argument >>> + * @index: the first buffer to be deleted >>> + * @count: number of buffers to delete >>> + * @type: enum v4l2_buf_type >>> + * @reserved: future extensions >>> + */ >>> +struct v4l2_delete_buffers { >>> + __u32 index; >>> + __u32 count; >>> + __u32 type; >>> + __u32 reserved[13]; >>> +}; >>> + >>> /* >>> * I O C T L C O D E S F O R V I D E O D E V I C E S >>> * >>> @@ -2715,6 +2729,8 @@ struct v4l2_create_buffers { >>> #define VIDIOC_DBG_G_CHIP_INFO _IOWR('V', 102, struct v4l2_dbg_chip_info) >>> #define VIDIOC_QUERY_EXT_CTRL _IOWR('V', 103, struct v4l2_query_ext_ctrl) >>> +#define VIDIOC_DELETE_BUFS _IOWR('V', 104, struct v4l2_delete_buffers) >>> + >>> /* Reminder: when adding new ioctls please add support for them to >>> drivers/media/v4l2-core/v4l2-compat-ioctl32.c as well! */ >> You need much more extensive compliance checks for this, esp. mixing >> create_bufs and delete_bufs. And test it with the test-media test script. >> >> Regards, >> >> Hans >> Regards, Hans
diff --git a/Documentation/userspace-api/media/v4l/user-func.rst b/Documentation/userspace-api/media/v4l/user-func.rst index 15ff0bf7bbe6..3fd567695477 100644 --- a/Documentation/userspace-api/media/v4l/user-func.rst +++ b/Documentation/userspace-api/media/v4l/user-func.rst @@ -17,6 +17,7 @@ Function Reference vidioc-dbg-g-chip-info vidioc-dbg-g-register vidioc-decoder-cmd + vidioc-delete-bufs vidioc-dqevent vidioc-dv-timings-cap vidioc-encoder-cmd diff --git a/Documentation/userspace-api/media/v4l/vidioc-delete-bufs.rst b/Documentation/userspace-api/media/v4l/vidioc-delete-bufs.rst new file mode 100644 index 000000000000..a55fe6331fc8 --- /dev/null +++ b/Documentation/userspace-api/media/v4l/vidioc-delete-bufs.rst @@ -0,0 +1,73 @@ +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later +.. c:namespace:: V4L + +.. _VIDIOC_DELETE_BUFS: + +************************ +ioctl VIDIOC_DELETE_BUFS +************************ + +Name +==== + +VIDIOC_DELETE_BUFS - Deletes buffers from a queue + +Synopsis +======== + +.. c:macro:: VIDIOC_DELETE_BUFs + +``int ioctl(int fd, VIDIOC_DELETE_BUFs, struct v4l2_delete_buffers *argp)`` + +Arguments +========= + +``fd`` + File descriptor returned by :c:func:`open()`. + +``argp`` + Pointer to struct :c:type:`v4l2_delete_buffers`. + +Description +=========== + +Applications can optionally call the :ref:`VIDIOC_DELETE_BUFS` ioctl to +delete buffers from a queue. + +.. c:type:: v4l2_delete_buffers + +.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.5cm}| + +.. flat-table:: struct v4l2_delete_buffers + :header-rows: 0 + :stub-columns: 0 + :widths: 1 1 2 + + * - __u32 + - ``index`` + - The starting buffer index to delete. + * - __u32 + - ``count`` + - The number of buffers to be deleted. + * - __u32 + - ``type`` + - Type of the stream or buffers, this is the same as the struct + :c:type:`v4l2_format` ``type`` field. See + :c:type:`v4l2_buf_type` for valid values. + * - __u32 + - ``reserved``\ [13] + - A place holder for future extensions. Drivers and applications + must set the array to zero. + +Return Value +============ + +On success 0 is returned, on error -1 and the ``errno`` variable is set +appropriately. The generic error codes are described at the +:ref:`Generic Error Codes <gen-errors>` chapter. + +EBUSY + File I/O is in progress. + +EINVAL + The buffer ``index`` doesn't exist in the queue. diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c index dc7f6b59d237..9edb2a1e95fc 100644 --- a/drivers/media/common/videobuf2/videobuf2-core.c +++ b/drivers/media/common/videobuf2/videobuf2-core.c @@ -1633,6 +1633,30 @@ int vb2_core_prepare_buf(struct vb2_queue *q, struct vb2_buffer *vb, void *pb) } EXPORT_SYMBOL_GPL(vb2_core_prepare_buf); +int vb2_core_delete_buf(struct vb2_queue *q, struct vb2_buffer *vb) +{ + mutex_lock(&q->mmap_lock); + if (vb->planes[0].mem_priv) + call_void_vb_qop(vb, buf_cleanup, vb); + + /* Free MMAP buffers or release USERPTR buffers */ + if (q->memory == VB2_MEMORY_MMAP) + __vb2_buf_mem_free(vb); + else if (q->memory == VB2_MEMORY_DMABUF) + __vb2_buf_dmabuf_put(vb); + else + __vb2_buf_userptr_put(vb); + + vb2_queue_remove_buffer(q, vb); + mutex_unlock(&q->mmap_lock); + + dprintk(q, 2, "buffer %d deleted\n", vb->index); + kfree(vb); + + return 0; +} +EXPORT_SYMBOL_GPL(vb2_core_delete_buf); + /* * vb2_start_streaming() - Attempt to start streaming. * @q: videobuf2 queue diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c index 8ba658ad9891..d0098f58a65c 100644 --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c @@ -385,7 +385,7 @@ static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct media_device *md vb = vb2_get_buffer(q, b->index); if (!vb) { - dprintk(q, 1, "%s: buffer is NULL\n", opname); + dprintk(q, 1, "%s: buffer %u was deleted\n", opname, b->index); return -EINVAL; } @@ -757,6 +757,42 @@ int vb2_prepare_buf(struct vb2_queue *q, struct media_device *mdev, } EXPORT_SYMBOL_GPL(vb2_prepare_buf); +int vb2_delete_bufs(struct vb2_queue *q, struct v4l2_delete_buffers *d) +{ + struct vb2_buffer *vb; + unsigned int index; + int ret = 0; + + if (d->index > q->num_buffers || + d->count > q->num_buffers || + (d->index + d->count) > q->num_buffers) { + return -EINVAL; + } + + for (index = d->index; index < d->index + d->count; index++) { + vb = vb2_get_buffer(q, index); + if (!vb) { + dprintk(q, 1, "can't find the requested buffer\n"); + ret = -EINVAL; + goto error; + } + if (vb->state != VB2_BUF_STATE_DEQUEUED) { + dprintk(q, 1, "can't delete non dequeued buffer index %d\n", vb->index); + ret = -EINVAL; + goto error; + } + + ret = vb2_core_delete_buf(q, vb); + if (ret) + break; + } + +error: + d->index = index; + return ret; +} +EXPORT_SYMBOL_GPL(vb2_delete_bufs); + int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create) { unsigned requested_planes = 1; diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c index f81279492682..215654fd6581 100644 --- a/drivers/media/v4l2-core/v4l2-dev.c +++ b/drivers/media/v4l2-core/v4l2-dev.c @@ -720,6 +720,7 @@ static void determine_valid_ioctls(struct video_device *vdev) SET_VALID_IOCTL(ops, VIDIOC_PREPARE_BUF, vidioc_prepare_buf); SET_VALID_IOCTL(ops, VIDIOC_STREAMON, vidioc_streamon); SET_VALID_IOCTL(ops, VIDIOC_STREAMOFF, vidioc_streamoff); + SET_VALID_IOCTL(ops, VIDIOC_DELETE_BUFS, vidioc_delete_bufs); } if (is_vid || is_vbi || is_meta) { diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c index f4d9d6279094..aac3a0ea0126 100644 --- a/drivers/media/v4l2-core/v4l2-ioctl.c +++ b/drivers/media/v4l2-core/v4l2-ioctl.c @@ -489,6 +489,13 @@ static void v4l_print_create_buffers(const void *arg, bool write_only) v4l_print_format(&p->format, write_only); } +static void v4l_print_delete_buffers(const void *arg, bool write_only) +{ + const struct v4l2_delete_buffers *p = arg; + + pr_cont("index=%d, count=%d\n", p->index, p->count); +} + static void v4l_print_streamparm(const void *arg, bool write_only) { const struct v4l2_streamparm *p = arg; @@ -2160,6 +2167,15 @@ static int v4l_prepare_buf(const struct v4l2_ioctl_ops *ops, return ret ? ret : ops->vidioc_prepare_buf(file, fh, b); } +static int v4l_delete_bufs(const struct v4l2_ioctl_ops *ops, + struct file *file, void *fh, void *arg) +{ + struct v4l2_delete_buffers *delete = arg; + int ret = check_fmt(file, delete->type); + + return ret ? ret : ops->vidioc_delete_bufs(file, fh, delete); +} + static int v4l_g_parm(const struct v4l2_ioctl_ops *ops, struct file *file, void *fh, void *arg) { @@ -2909,6 +2925,7 @@ static const struct v4l2_ioctl_info v4l2_ioctls[] = { IOCTL_INFO(VIDIOC_ENUM_FREQ_BANDS, v4l_enum_freq_bands, v4l_print_freq_band, 0), IOCTL_INFO(VIDIOC_DBG_G_CHIP_INFO, v4l_dbg_g_chip_info, v4l_print_dbg_chip_info, INFO_FL_CLEAR(v4l2_dbg_chip_info, match)), IOCTL_INFO(VIDIOC_QUERY_EXT_CTRL, v4l_query_ext_ctrl, v4l_print_query_ext_ctrl, INFO_FL_CTRL | INFO_FL_CLEAR(v4l2_query_ext_ctrl, id)), + IOCTL_INFO(VIDIOC_DELETE_BUFS, v4l_delete_bufs, v4l_print_delete_buffers, INFO_FL_PRIO | INFO_FL_QUEUE | INFO_FL_CLEAR(v4l2_delete_buffers, type)), }; #define V4L2_IOCTLS ARRAY_SIZE(v4l2_ioctls) diff --git a/include/media/v4l2-ioctl.h b/include/media/v4l2-ioctl.h index edb733f21604..55afbde54211 100644 --- a/include/media/v4l2-ioctl.h +++ b/include/media/v4l2-ioctl.h @@ -163,6 +163,8 @@ struct v4l2_fh; * :ref:`VIDIOC_CREATE_BUFS <vidioc_create_bufs>` ioctl * @vidioc_prepare_buf: pointer to the function that implements * :ref:`VIDIOC_PREPARE_BUF <vidioc_prepare_buf>` ioctl + * @vidioc_delete_bufs: pointer to the function that implements + * :ref:`VIDIOC_DELETE_BUFS <vidioc_delete_bufs>` ioctl * @vidioc_overlay: pointer to the function that implements * :ref:`VIDIOC_OVERLAY <vidioc_overlay>` ioctl * @vidioc_g_fbuf: pointer to the function that implements @@ -422,6 +424,8 @@ struct v4l2_ioctl_ops { struct v4l2_create_buffers *b); int (*vidioc_prepare_buf)(struct file *file, void *fh, struct v4l2_buffer *b); + int (*vidioc_delete_bufs)(struct file *file, void *fh, + struct v4l2_delete_buffers *d); int (*vidioc_overlay)(struct file *file, void *fh, unsigned int i); int (*vidioc_g_fbuf)(struct file *file, void *fh, diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h index 97153c69583f..e2c5ff31efd0 100644 --- a/include/media/videobuf2-core.h +++ b/include/media/videobuf2-core.h @@ -843,6 +843,15 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory, */ int vb2_core_prepare_buf(struct vb2_queue *q, struct vb2_buffer *vb, void *pb); +/** + * vb2_core_delete_buf() - + * @q: pointer to &struct vb2_queue with videobuf2 queue. + * @vb: pointer to struct &vb2_buffer. + * + * Return: returns zero on success; an error code otherwise. + */ +int vb2_core_delete_buf(struct vb2_queue *q, struct vb2_buffer *vb); + /** * vb2_core_qbuf() - Queue a buffer from userspace * diff --git a/include/media/videobuf2-v4l2.h b/include/media/videobuf2-v4l2.h index 5a845887850b..2ef68fdf388f 100644 --- a/include/media/videobuf2-v4l2.h +++ b/include/media/videobuf2-v4l2.h @@ -118,6 +118,17 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create); */ int vb2_prepare_buf(struct vb2_queue *q, struct media_device *mdev, struct v4l2_buffer *b); +/** + * vb2_delete_bufs() - Delete buffers from the queue + * + * @q: pointer to &struct vb2_queue with videobuf2 queue. + * @d: delete parameter, passed from userspace to + * &v4l2_ioctl_ops->vidioc_delete_bufs handler in driver + * + * The return values from this function are intended to be directly returned + * from &v4l2_ioctl_ops->vidioc_delete_bufs handler in driver. + */ +int vb2_delete_bufs(struct vb2_queue *q, struct v4l2_delete_buffers *d); /** * vb2_qbuf() - Queue a buffer from userspace diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h index 78260e5d9985..9cc7f570d995 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h @@ -2616,6 +2616,20 @@ struct v4l2_create_buffers { __u32 reserved[6]; }; +/** + * struct v4l2_delete_buffers - VIDIOC_DELETE_BUFS argument + * @index: the first buffer to be deleted + * @count: number of buffers to delete + * @type: enum v4l2_buf_type + * @reserved: future extensions + */ +struct v4l2_delete_buffers { + __u32 index; + __u32 count; + __u32 type; + __u32 reserved[13]; +}; + /* * I O C T L C O D E S F O R V I D E O D E V I C E S * @@ -2715,6 +2729,8 @@ struct v4l2_create_buffers { #define VIDIOC_DBG_G_CHIP_INFO _IOWR('V', 102, struct v4l2_dbg_chip_info) #define VIDIOC_QUERY_EXT_CTRL _IOWR('V', 103, struct v4l2_query_ext_ctrl) +#define VIDIOC_DELETE_BUFS _IOWR('V', 104, struct v4l2_delete_buffers) + /* Reminder: when adding new ioctls please add support for them to drivers/media/v4l2-core/v4l2-compat-ioctl32.c as well! */
VIDIOC_DELETE_BUFS ioctl allows to delete buffers from a queue. The number of buffers to delete in given by count field of struct v4l2_delete_buffers and the range start at the index specified in the same structure. Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com> --- v6: - Add lock in vb2_core_delete_buf() - Fix typo and comments - Add flags in VIDIOC_DELETE_BUFS decalaration .../userspace-api/media/v4l/user-func.rst | 1 + .../media/v4l/vidioc-delete-bufs.rst | 73 +++++++++++++++++++ .../media/common/videobuf2/videobuf2-core.c | 24 ++++++ .../media/common/videobuf2/videobuf2-v4l2.c | 38 +++++++++- drivers/media/v4l2-core/v4l2-dev.c | 1 + drivers/media/v4l2-core/v4l2-ioctl.c | 17 +++++ include/media/v4l2-ioctl.h | 4 + include/media/videobuf2-core.h | 9 +++ include/media/videobuf2-v4l2.h | 11 +++ include/uapi/linux/videodev2.h | 16 ++++ 10 files changed, 193 insertions(+), 1 deletion(-) create mode 100644 Documentation/userspace-api/media/v4l/vidioc-delete-bufs.rst