2024-02-21 15:56:18

by Benjamin Gaignard

[permalink] [raw]
Subject: [PATCH v20 4/9] media: core: Rework how create_buf index returned value is computed

When REMOVE_BUFS will be introduced holes could created in bufs array.
To be able to reuse these unused indices reworking how create->index
is set is mandatory.
Let __vb2_queue_alloc() decide which first index is correct and
forward this to the caller.

Signed-off-by: Benjamin Gaignard <[email protected]>
---
.../media/common/videobuf2/videobuf2-core.c | 18 +++++++++++++-----
.../media/common/videobuf2/videobuf2-v4l2.c | 14 +++++++++-----
include/media/videobuf2-core.h | 5 ++++-
3 files changed, 26 insertions(+), 11 deletions(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index 58c495b253ce..8e819d198c34 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -442,12 +442,15 @@ static void vb2_queue_remove_buffer(struct vb2_buffer *vb)
* __vb2_queue_alloc() - allocate vb2 buffer structures and (for MMAP type)
* video buffer memory for all buffers/planes on the queue and initializes the
* queue
+ * @first_index: index of the first created buffer, all newly allocated buffers
+ * have indices in the range [first_index..first_index+count-1]
*
* Returns the number of buffers successfully allocated.
*/
static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
unsigned int num_buffers, unsigned int num_planes,
- const unsigned plane_sizes[VB2_MAX_PLANES])
+ const unsigned int plane_sizes[VB2_MAX_PLANES],
+ unsigned int *first_index)
{
unsigned int q_num_buffers = vb2_get_num_buffers(q);
unsigned int buffer, plane;
@@ -461,6 +464,8 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
num_buffers = min_t(unsigned int, num_buffers,
q->max_num_buffers - q_num_buffers);

+ *first_index = q_num_buffers;
+
for (buffer = 0; buffer < num_buffers; ++buffer) {
/* Allocate vb2 buffer structures */
vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
@@ -820,7 +825,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
unsigned int q_num_bufs = vb2_get_num_buffers(q);
unsigned plane_sizes[VB2_MAX_PLANES] = { };
bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
- unsigned int i;
+ unsigned int i, first_index;
int ret = 0;

if (q->streaming) {
@@ -907,8 +912,10 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,

/* Finally, allocate buffers and video memory */
allocated_buffers =
- __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes);
+ __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes, &first_index);
if (allocated_buffers == 0) {
+ /* There shouldn't be any buffers allocated, so first_index == 0 */
+ WARN_ON(first_index);
dprintk(q, 1, "memory allocation failed\n");
ret = -ENOMEM;
goto error;
@@ -982,7 +989,8 @@ EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
unsigned int flags, unsigned int *count,
unsigned int requested_planes,
- const unsigned int requested_sizes[])
+ const unsigned int requested_sizes[],
+ unsigned int *first_index)
{
unsigned int num_planes = 0, num_buffers, allocated_buffers;
unsigned plane_sizes[VB2_MAX_PLANES] = { };
@@ -1044,7 +1052,7 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,

/* Finally, allocate buffers and video memory */
allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers,
- num_planes, plane_sizes);
+ num_planes, plane_sizes, first_index);
if (allocated_buffers == 0) {
dprintk(q, 1, "memory allocation failed\n");
ret = -ENOMEM;
diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
index c575198e8354..03e8080a68a8 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -795,11 +795,15 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
for (i = 0; i < requested_planes; i++)
if (requested_sizes[i] == 0)
return -EINVAL;
- return ret ? ret : vb2_core_create_bufs(q, create->memory,
- create->flags,
- &create->count,
- requested_planes,
- requested_sizes);
+ if (ret)
+ return ret;
+
+ return vb2_core_create_bufs(q, create->memory,
+ create->flags,
+ &create->count,
+ requested_planes,
+ requested_sizes,
+ &create->index);
}
EXPORT_SYMBOL_GPL(vb2_create_bufs);

diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index 2ca120f18edf..ee0cbd8705ec 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -823,6 +823,8 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
* @count: requested buffer count.
* @requested_planes: number of planes requested.
* @requested_sizes: array with the size of the planes.
+ * @first_index: index of the first created buffer, all allocated buffers have
+ * indices in the range [first_index..first_index+count-1]
*
* Videobuf2 core helper to implement VIDIOC_CREATE_BUFS() operation. It is
* called internally by VB2 by an API-specific handler, like
@@ -839,7 +841,8 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
unsigned int flags, unsigned int *count,
unsigned int requested_planes,
- const unsigned int requested_sizes[]);
+ const unsigned int requested_sizes[],
+ unsigned int *first_index);

/**
* vb2_core_prepare_buf() - Pass ownership of a buffer from userspace
--
2.40.1