VIDIOC_DELETE_BUF ioctl allows to delete a buffer from a queue.
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
---
.../userspace-api/media/v4l/user-func.rst | 1 +
.../media/v4l/vidioc-delete-buf.rst | 51 ++++++++++++++++
.../media/common/videobuf2/videobuf2-core.c | 59 ++++++++++++++++++-
.../media/common/videobuf2/videobuf2-v4l2.c | 6 ++
drivers/media/v4l2-core/v4l2-dev.c | 1 +
drivers/media/v4l2-core/v4l2-ioctl.c | 10 ++++
include/media/v4l2-ioctl.h | 4 ++
include/media/videobuf2-core.h | 9 +++
include/media/videobuf2-v4l2.h | 11 ++++
include/uapi/linux/videodev2.h | 1 +
10 files changed, 152 insertions(+), 1 deletion(-)
create mode 100644 Documentation/userspace-api/media/v4l/vidioc-delete-buf.rst
diff --git a/Documentation/userspace-api/media/v4l/user-func.rst b/Documentation/userspace-api/media/v4l/user-func.rst
index 228c1521f190..93e0a6a117fc 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-buf
vidioc-dqevent
vidioc-dv-timings-cap
vidioc-encoder-cmd
diff --git a/Documentation/userspace-api/media/v4l/vidioc-delete-buf.rst b/Documentation/userspace-api/media/v4l/vidioc-delete-buf.rst
new file mode 100644
index 000000000000..0e7ce58f91bc
--- /dev/null
+++ b/Documentation/userspace-api/media/v4l/vidioc-delete-buf.rst
@@ -0,0 +1,51 @@
+.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
+.. c:namespace:: V4L
+
+.. _VIDIOC_DELETE_BUF:
+
+************************
+ioctl VIDIOC_DELETE_BUF
+************************
+
+Name
+====
+
+VIDIOC_DELETE_BUF - Delete a buffer from a queue
+
+Synopsis
+========
+
+.. c:macro:: VIDIOC_DELETE_BUF
+
+``int ioctl(int fd, VIDIOC_DELETE_BUF, struct v4l2_buffer *argp)``
+
+Arguments
+=========
+
+``fd``
+ File descriptor returned by :c:func:`open()`.
+
+``argp``
+ Pointer to struct :c:type:`v4l2_buffer`.
+
+Description
+===========
+
+Applications can optionally call the :ref:`VIDIOC_DELETE_BUF` ioctl to
+delete a buffer from a queue.
+
+The struct :c:type:`v4l2_buffer` structure is specified in
+:ref:`buffer`.
+
+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 3c6ced360770..ec241d726fe6 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -401,6 +401,24 @@ static void init_buffer_cache_hints(struct vb2_queue *q, struct vb2_buffer *vb)
vb->skip_cache_sync_on_finish = 1;
}
+/*
+ * __vb2_queue_get_free_index() - find a free index in the queue for vb2 buffer.
+ *
+ * Returns an index for vb2 buffer.
+ */
+static int __vb2_queue_get_free_index(struct vb2_queue *q)
+{
+ int i;
+
+ spin_lock(&q->bufs_lock);
+ for (i = 0; i < q->max_num_bufs; i++)
+ if (!q->bufs[i])
+ break;
+ spin_unlock(&q->bufs_lock);
+
+ return i;
+}
+
/*
* __vb2_queue_alloc() - allocate vb2 buffer structures and (for MMAP type)
* video buffer memory for all buffers/planes on the queue and initializes the
@@ -427,7 +445,7 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
vb->state = VB2_BUF_STATE_DEQUEUED;
vb->vb2_queue = q;
vb->num_planes = num_planes;
- vb->index = q->num_buffers + buffer;
+ vb->index = __vb2_queue_get_free_index(q);
vb->type = q->type;
vb->memory = memory;
init_buffer_cache_hints(q, vb);
@@ -1570,6 +1588,45 @@ int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
}
EXPORT_SYMBOL_GPL(vb2_core_prepare_buf);
+int vb2_core_delete_buf(struct vb2_queue *q, unsigned int index)
+{
+ struct vb2_buffer *vb;
+
+ vb = vb2_get_buffer(q, index);
+ if (!vb) {
+ dprintk(q, 1, "invalid buffer index %d\n", index);
+ return -EINVAL;
+ }
+
+ if (vb->state == VB2_BUF_STATE_QUEUED) {
+ dprintk(q, 1, "can't delete queued buffer index %d\n", index);
+ return -EINVAL;
+ }
+
+ if (vb && 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);
+ kfree(vb);
+
+ q->num_buffers--;
+ if (!q->num_buffers) {
+ q->memory = VB2_MEMORY_UNKNOWN;
+ INIT_LIST_HEAD(&q->queued_list);
+ }
+
+ dprintk(q, 2, "buffer %d deleted\n", index);
+ return 0;
+}
+
/*
* 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 01b2bb957239..7d0b4ed48a06 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -742,6 +742,12 @@ int vb2_prepare_buf(struct vb2_queue *q, struct media_device *mdev,
}
EXPORT_SYMBOL_GPL(vb2_prepare_buf);
+int vb2_delete_buf(struct vb2_queue *q, struct v4l2_buffer *b)
+{
+ return vb2_core_delete_buf(q, b->index);
+}
+EXPORT_SYMBOL_GPL(vb2_delete_buf);
+
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 397d553177fa..4f49d2115838 100644
--- a/drivers/media/v4l2-core/v4l2-dev.c
+++ b/drivers/media/v4l2-core/v4l2-dev.c
@@ -719,6 +719,7 @@ 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_BUF, vidioc_delete_buf);
}
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 87f163a89c80..2e0af50cac45 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -2152,6 +2152,15 @@ 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_buf(const struct v4l2_ioctl_ops *ops,
+ struct file *file, void *fh, void *arg)
+{
+ struct v4l2_buffer *b = arg;
+ int ret = check_fmt(file, b->type);
+
+ return ret ? ret : ops->vidioc_delete_buf(file, fh, b);
+}
+
static int v4l_g_parm(const struct v4l2_ioctl_ops *ops,
struct file *file, void *fh, void *arg)
{
@@ -2902,6 +2911,7 @@ 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_BUF, v4l_delete_buf, v4l_print_buffer, INFO_FL_QUEUE),
};
#define V4L2_IOCTLS ARRAY_SIZE(v4l2_ioctls)
diff --git a/include/media/v4l2-ioctl.h b/include/media/v4l2-ioctl.h
index edb733f21604..2f232ed884c7 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_buf: pointer to the function that implements
+ * :ref:`VIDIOC_DELETE_BUF <vidioc_delete_buf>` 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_buf)(struct file *file, void *fh,
+ struct v4l2_buffer *b);
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 4aa43c5c7c58..16e95278f6e8 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -847,6 +847,15 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
*/
int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb);
+/**
+ * vb2_core_delete_buf() -
+ * @q: pointer to &struct vb2_queue with videobuf2 queue.
+ * @index: id number of the buffer.
+ *
+ * Return: returns zero on success; an error code otherwise.
+ */
+int vb2_core_delete_buf(struct vb2_queue *q, unsigned int index);
+
/**
* vb2_core_qbuf() - Queue a buffer from userspace
*
diff --git a/include/media/videobuf2-v4l2.h b/include/media/videobuf2-v4l2.h
index 88a7a565170e..3beeb4c735f0 100644
--- a/include/media/videobuf2-v4l2.h
+++ b/include/media/videobuf2-v4l2.h
@@ -114,6 +114,17 @@ 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_buf() - Delete the buffer from the queue
+ *
+ * @q: pointer to &struct vb2_queue with videobuf2 queue.
+ * @b: buffer structure passed from userspace to
+ * &v4l2_ioctl_ops->vidioc_delete_buf handler in driver
+ *
+ * The return values from this function are intended to be directly returned
+ * from &v4l2_ioctl_ops->vidioc_delete_buf handler in driver.
+ */
+int vb2_delete_buf(struct vb2_queue *q, struct v4l2_buffer *b);
/**
* vb2_qbuf() - Queue a buffer from userspace
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 17a9b975177a..9cee9ccf1da8 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -2681,6 +2681,7 @@ struct v4l2_create_buffers {
#define VIDIOC_QUERY_DV_TIMINGS _IOR('V', 99, struct v4l2_dv_timings)
#define VIDIOC_DV_TIMINGS_CAP _IOWR('V', 100, struct v4l2_dv_timings_cap)
#define VIDIOC_ENUM_FREQ_BANDS _IOWR('V', 101, struct v4l2_frequency_band)
+#define VIDIOC_DELETE_BUF _IOWR('V', 102, struct v4l2_buffer)
/*
* Experimental, meant for debugging, testing and internal use.
--
2.34.1
On Tue, Mar 21, 2023 at 11:28:52AM +0100, Benjamin Gaignard wrote: > VIDIOC_DELETE_BUF ioctl allows to delete a buffer from a queue. > > Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com> > --- > .../userspace-api/media/v4l/user-func.rst | 1 + > .../media/v4l/vidioc-delete-buf.rst | 51 ++++++++++++++++ > .../media/common/videobuf2/videobuf2-core.c | 59 ++++++++++++++++++- > .../media/common/videobuf2/videobuf2-v4l2.c | 6 ++ > drivers/media/v4l2-core/v4l2-dev.c | 1 + > drivers/media/v4l2-core/v4l2-ioctl.c | 10 ++++ > include/media/v4l2-ioctl.h | 4 ++ > include/media/videobuf2-core.h | 9 +++ > include/media/videobuf2-v4l2.h | 11 ++++ > include/uapi/linux/videodev2.h | 1 + > 10 files changed, 152 insertions(+), 1 deletion(-) > create mode 100644 Documentation/userspace-api/media/v4l/vidioc-delete-buf.rst > > diff --git a/Documentation/userspace-api/media/v4l/user-func.rst b/Documentation/userspace-api/media/v4l/user-func.rst > index 228c1521f190..93e0a6a117fc 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-buf > vidioc-dqevent > vidioc-dv-timings-cap > vidioc-encoder-cmd > diff --git a/Documentation/userspace-api/media/v4l/vidioc-delete-buf.rst b/Documentation/userspace-api/media/v4l/vidioc-delete-buf.rst > new file mode 100644 > index 000000000000..0e7ce58f91bc > --- /dev/null > +++ b/Documentation/userspace-api/media/v4l/vidioc-delete-buf.rst > @@ -0,0 +1,51 @@ > +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later > +.. c:namespace:: V4L > + > +.. _VIDIOC_DELETE_BUF: > + > +************************ > +ioctl VIDIOC_DELETE_BUF > +************************ > + > +Name > +==== > + > +VIDIOC_DELETE_BUF - Delete a buffer from a queue > + > +Synopsis > +======== > + > +.. c:macro:: VIDIOC_DELETE_BUF > + > +``int ioctl(int fd, VIDIOC_DELETE_BUF, struct v4l2_buffer *argp)`` > + > +Arguments > +========= > + > +``fd`` > + File descriptor returned by :c:func:`open()`. > + > +``argp`` > + Pointer to struct :c:type:`v4l2_buffer`. Would struct v4l2_create_buffers make more sense here? With it, we could actually make this ioctl VIDIOC_DELETE_BUF*S*, consistently with VIDIOC_CREATE_BUF*S* and allow the user space to remove a block of buffers the same way it created a block of buffers in the first place. > + > +Description > +=========== > + > +Applications can optionally call the :ref:`VIDIOC_DELETE_BUF` ioctl to > +delete a buffer from a queue. > + > +The struct :c:type:`v4l2_buffer` structure is specified in > +:ref:`buffer`. > + > +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 3c6ced360770..ec241d726fe6 100644 > --- a/drivers/media/common/videobuf2/videobuf2-core.c > +++ b/drivers/media/common/videobuf2/videobuf2-core.c > @@ -401,6 +401,24 @@ static void init_buffer_cache_hints(struct vb2_queue *q, struct vb2_buffer *vb) > vb->skip_cache_sync_on_finish = 1; > } > > +/* > + * __vb2_queue_get_free_index() - find a free index in the queue for vb2 buffer. > + * > + * Returns an index for vb2 buffer. > + */ > +static int __vb2_queue_get_free_index(struct vb2_queue *q) > +{ > + int i; > + > + spin_lock(&q->bufs_lock); > + for (i = 0; i < q->max_num_bufs; i++) > + if (!q->bufs[i]) > + break; > + spin_unlock(&q->bufs_lock); > + > + return i; > +} Another reason to go with XArray, so that we don't have to open code index reclaim. > + > /* > * __vb2_queue_alloc() - allocate vb2 buffer structures and (for MMAP type) > * video buffer memory for all buffers/planes on the queue and initializes the > @@ -427,7 +445,7 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory, > vb->state = VB2_BUF_STATE_DEQUEUED; > vb->vb2_queue = q; > vb->num_planes = num_planes; > - vb->index = q->num_buffers + buffer; > + vb->index = __vb2_queue_get_free_index(q); > vb->type = q->type; > vb->memory = memory; > init_buffer_cache_hints(q, vb); > @@ -1570,6 +1588,45 @@ int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb) > } > EXPORT_SYMBOL_GPL(vb2_core_prepare_buf); > > +int vb2_core_delete_buf(struct vb2_queue *q, unsigned int index) > +{ > + struct vb2_buffer *vb; > + > + vb = vb2_get_buffer(q, index); > + if (!vb) { > + dprintk(q, 1, "invalid buffer index %d\n", index); > + return -EINVAL; > + } > + > + if (vb->state == VB2_BUF_STATE_QUEUED) { How about other states? I'd probably only allow this when the state is DEQUEUED for simplicity. Is there a need to allow deleting buffers in other states? Also, do we need to synchronize this with other contexts which could change the buffer state? > + dprintk(q, 1, "can't delete queued buffer index %d\n", index); > + return -EINVAL; > + } > + Don't we also need to hold q->mmap_lock to prevent racing with an attempt to mmap the buffer? > + if (vb && vb->planes[0].mem_priv) nit: At this point it's not possible for vb to be NULL, since we already ruled that out a few lines above. > + 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); > + kfree(vb); > + > + q->num_buffers--; > + if (!q->num_buffers) { > + q->memory = VB2_MEMORY_UNKNOWN; > + INIT_LIST_HEAD(&q->queued_list); > + } Would it make sense to refactor __vb2_queue_free() instead to take a range of buffer indexes rather than duplicating the code here? Best regards, Tomasz
Hi Benjamin, I love your patch! Yet something to improve: [auto build test ERROR on media-tree/master] [also build test ERROR on linus/master v6.3-rc3 next-20230321] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Benjamin-Gaignard/media-videobuf2-Access-vb2_queue-bufs-array-through-helper-functions/20230321-183154 base: git://linuxtv.org/media_tree.git master patch link: https://lore.kernel.org/r/20230321102855.346732-6-benjamin.gaignard%40collabora.com patch subject: [PATCH v2 5/8] media: v4l2: Add DELETE_BUF ioctl config: x86_64-randconfig-a002-20230320 (https://download.01.org/0day-ci/archive/20230322/202303220359.f1UOGBNV-lkp@intel.com/config) compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://github.com/intel-lab-lkp/linux/commit/c33ab7329647eb04482423ac9945dee579038e84 git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Benjamin-Gaignard/media-videobuf2-Access-vb2_queue-bufs-array-through-helper-functions/20230321-183154 git checkout c33ab7329647eb04482423ac9945dee579038e84 # save the config file mkdir build_dir && cp config build_dir/.config COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 olddefconfig COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash If you fix the issue, kindly add following tag where applicable | Reported-by: kernel test robot <lkp@intel.com> | Link: https://lore.kernel.org/oe-kbuild-all/202303220359.f1UOGBNV-lkp@intel.com/ All errors (new ones prefixed by >>, old ones prefixed by <<): >> ERROR: modpost: "vb2_core_delete_buf" [drivers/media/common/videobuf2/videobuf2-v4l2.ko] undefined! -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests
© 2016 - 2024 Red Hat, Inc.