[RFC 1/4] media: videobuf2: Use vb2_get_buffer() as helper everywhere

From: Benjamin Gaignard
Date: Mon Mar 13 2023 - 10:00:26 EST


The first step before changing how vb2 buffers are stored into queue
is to avoid direct call to bufs arrays.
This patch add 2 helpers functions to set and delete vb2 buffers
from a queue. With these 2 and vb2_get_buffer(), bufs field of
struct vb2_queue becomes like a private member of the structure.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxxxxx>
---
.../media/common/videobuf2/videobuf2-core.c | 69 ++++++++++---------
.../media/common/videobuf2/videobuf2-v4l2.c | 17 +++--
drivers/media/platform/amphion/vpu_dbg.c | 4 +-
.../platform/mediatek/jpeg/mtk_jpeg_core.c | 2 +-
.../vcodec/vdec/vdec_vp9_req_lat_if.c | 2 +-
drivers/media/test-drivers/visl/visl-dec.c | 16 +++--
include/media/videobuf2-core.h | 20 ++++++
7 files changed, 81 insertions(+), 49 deletions(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index cf6727d9c81f..b51152ace763 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -359,7 +359,7 @@ static void __setup_offsets(struct vb2_buffer *vb)
unsigned long off = 0;

if (vb->index) {
- struct vb2_buffer *prev = q->bufs[vb->index - 1];
+ struct vb2_buffer *prev = vb2_get_buffer(q, vb->index - 1);
struct vb2_plane *p = &prev->planes[prev->num_planes - 1];

off = PAGE_ALIGN(p->m.offset + p->length);
@@ -437,7 +437,7 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
}
call_void_bufop(q, init_buffer, vb);

- q->bufs[vb->index] = vb;
+ vb2_set_buffer(q, vb);

/* Allocate video buffer memory for the MMAP type */
if (memory == VB2_MEMORY_MMAP) {
@@ -445,7 +445,7 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
if (ret) {
dprintk(q, 1, "failed allocating memory for buffer %d\n",
buffer);
- q->bufs[vb->index] = NULL;
+ vb2_del_buffer(q, vb);
kfree(vb);
break;
}
@@ -460,7 +460,7 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
dprintk(q, 1, "buffer %d %p initialization failed\n",
buffer, vb);
__vb2_buf_mem_free(vb);
- q->bufs[vb->index] = NULL;
+ vb2_del_buffer(q, vb);
kfree(vb);
break;
}
@@ -483,7 +483,7 @@ static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)

for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
++buffer) {
- vb = q->bufs[buffer];
+ vb = vb2_get_buffer(q, buffer);
if (!vb)
continue;

@@ -511,7 +511,7 @@ static void __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
/* Call driver-provided cleanup function for each buffer, if provided */
for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
++buffer) {
- struct vb2_buffer *vb = q->bufs[buffer];
+ struct vb2_buffer *vb = vb2_get_buffer(q, buffer);

if (vb && vb->planes[0].mem_priv)
call_void_vb_qop(vb, buf_cleanup, vb);
@@ -591,8 +591,10 @@ static void __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
/* Free vb2 buffers */
for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
++buffer) {
- kfree(q->bufs[buffer]);
- q->bufs[buffer] = NULL;
+ struct vb2_buffer *vb2 = vb2_get_buffer(q, buffer);
+
+ vb2_del_buffer(q, vb2);
+ kfree(vb2);
}

q->num_buffers -= buffers;
@@ -628,7 +630,7 @@ static bool __buffers_in_use(struct vb2_queue *q)
{
unsigned int buffer;
for (buffer = 0; buffer < q->num_buffers; ++buffer) {
- if (vb2_buffer_in_use(q, q->bufs[buffer]))
+ if (vb2_buffer_in_use(q, vb2_get_buffer(q, buffer)))
return true;
}
return false;
@@ -636,7 +638,7 @@ static bool __buffers_in_use(struct vb2_queue *q)

void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb)
{
- call_void_bufop(q, fill_user_buffer, q->bufs[index], pb);
+ call_void_bufop(q, fill_user_buffer, vb2_get_buffer(q, index), pb);
}
EXPORT_SYMBOL_GPL(vb2_core_querybuf);

@@ -1547,7 +1549,7 @@ int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
struct vb2_buffer *vb;
int ret;

- vb = q->bufs[index];
+ vb = vb2_get_buffer(q, index);
if (vb->state != VB2_BUF_STATE_DEQUEUED) {
dprintk(q, 1, "invalid buffer state %s\n",
vb2_state_name(vb->state));
@@ -1618,7 +1620,7 @@ static int vb2_start_streaming(struct vb2_queue *q)
* correctly return them to vb2.
*/
for (i = 0; i < q->num_buffers; ++i) {
- vb = q->bufs[i];
+ vb = vb2_get_buffer(q, i);
if (vb->state == VB2_BUF_STATE_ACTIVE)
vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
}
@@ -1646,7 +1648,7 @@ int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
return -EIO;
}

- vb = q->bufs[index];
+ vb = vb2_get_buffer(q, index);

if (!req && vb->state != VB2_BUF_STATE_IN_REQUEST &&
q->requires_requests) {
@@ -2022,12 +2024,15 @@ static void __vb2_queue_cancel(struct vb2_queue *q)
* to vb2 in stop_streaming().
*/
if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
- for (i = 0; i < q->num_buffers; ++i)
- if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE) {
+ for (i = 0; i < q->num_buffers; ++i) {
+ struct vb2_buffer *vb2 = vb2_get_buffer(q, i);
+
+ if (vb2->state == VB2_BUF_STATE_ACTIVE) {
pr_warn("driver bug: stop_streaming operation is leaving buf %p in active state\n",
- q->bufs[i]);
- vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
+ vb2);
+ vb2_buffer_done(vb2, VB2_BUF_STATE_ERROR);
}
+ }
/* Must be zero now */
WARN_ON(atomic_read(&q->owned_by_drv_count));
}
@@ -2061,7 +2066,7 @@ static void __vb2_queue_cancel(struct vb2_queue *q)
* be changed, so we can't move the buf_finish() to __vb2_dqbuf().
*/
for (i = 0; i < q->num_buffers; ++i) {
- struct vb2_buffer *vb = q->bufs[i];
+ struct vb2_buffer *vb = vb2_get_buffer(q, i);
struct media_request *req = vb->req_obj.req;

/*
@@ -2215,7 +2220,7 @@ static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
* return its buffer and plane numbers.
*/
for (buffer = 0; buffer < q->num_buffers; ++buffer) {
- vb = q->bufs[buffer];
+ vb = vb2_get_buffer(q, buffer);

for (plane = 0; plane < vb->num_planes; ++plane) {
if (vb->planes[plane].m.offset == off) {
@@ -2262,7 +2267,7 @@ int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
return -EINVAL;
}

- vb = q->bufs[index];
+ vb = vb2_get_buffer(q, index);

if (plane >= vb->num_planes) {
dprintk(q, 1, "buffer plane out of range\n");
@@ -2339,7 +2344,7 @@ int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
if (ret)
goto unlock;

- vb = q->bufs[buffer];
+ vb = vb2_get_buffer(q, buffer);

/*
* MMAP requires page_aligned buffers.
@@ -2679,7 +2684,7 @@ static int __vb2_init_fileio(struct vb2_queue *q, int read)
* Check if plane_count is correct
* (multiplane buffers are not supported).
*/
- if (q->bufs[0]->num_planes != 1) {
+ if (vb2_get_buffer(q, 0)->num_planes != 1) {
ret = -EBUSY;
goto err_reqbufs;
}
@@ -2688,12 +2693,14 @@ static int __vb2_init_fileio(struct vb2_queue *q, int read)
* Get kernel address of each buffer.
*/
for (i = 0; i < q->num_buffers; i++) {
- fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
+ struct vb2_buffer *vb2 = vb2_get_buffer(q, i);
+
+ fileio->bufs[i].vaddr = vb2_plane_vaddr(vb2, 0);
if (fileio->bufs[i].vaddr == NULL) {
ret = -EINVAL;
goto err_reqbufs;
}
- fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
+ fileio->bufs[i].size = vb2_plane_size(vb2, 0);
}

/*
@@ -2821,15 +2828,15 @@ static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_

fileio->cur_index = index;
buf = &fileio->bufs[index];
- b = q->bufs[index];
+ b = vb2_get_buffer(q, index);

/*
* Get number of bytes filled by the driver
*/
buf->pos = 0;
buf->queued = 0;
- buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
- : vb2_plane_size(q->bufs[index], 0);
+ buf->size = read ? vb2_get_plane_payload(b, 0)
+ : vb2_plane_size(b, 0);
/* Compensate for data_offset on read in the multiplanar case. */
if (is_multiplanar && read &&
b->planes[0].data_offset < buf->size) {
@@ -2872,7 +2879,7 @@ static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_
* Queue next buffer if required.
*/
if (buf->pos == buf->size || (!read && fileio->write_immediately)) {
- struct vb2_buffer *b = q->bufs[index];
+ struct vb2_buffer *b = vb2_get_buffer(q, index);

/*
* Check if this is the last buffer to read.
@@ -2899,7 +2906,7 @@ static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_
*/
buf->pos = 0;
buf->queued = 1;
- buf->size = vb2_plane_size(q->bufs[index], 0);
+ buf->size = vb2_plane_size(vb2_get_buffer(q, index), 0);
fileio->q_count += 1;
/*
* If we are queuing up buffers for the first time, then
@@ -2970,7 +2977,7 @@ static int vb2_thread(void *data)
* Call vb2_dqbuf to get buffer back.
*/
if (prequeue) {
- vb = q->bufs[index++];
+ vb = vb2_get_buffer(q, index++);
prequeue--;
} else {
call_void_qop(q, wait_finish, q);
@@ -2979,7 +2986,7 @@ static int vb2_thread(void *data)
call_void_qop(q, wait_prepare, q);
dprintk(q, 5, "file io: vb2_dqbuf result: %d\n", ret);
if (!ret)
- vb = q->bufs[index];
+ vb = vb2_get_buffer(q, index);
}
if (ret || threadio->stop)
break;
diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
index 1f5d235a8441..01b2bb957239 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -383,7 +383,7 @@ static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct media_device *md
return -EINVAL;
}

- if (q->bufs[b->index] == NULL) {
+ if (!vb2_get_buffer(q, b->index)) {
/* Should never happen */
dprintk(q, 1, "%s: buffer is NULL\n", opname);
return -EINVAL;
@@ -394,7 +394,7 @@ static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct media_device *md
return -EINVAL;
}

- vb = q->bufs[b->index];
+ vb = vb2_get_buffer(q, b->index);
vbuf = to_vb2_v4l2_buffer(vb);
ret = __verify_planes_array(vb, b);
if (ret)
@@ -628,11 +628,14 @@ static const struct vb2_buf_ops v4l2_buf_ops = {
struct vb2_buffer *vb2_find_buffer(struct vb2_queue *q, u64 timestamp)
{
unsigned int i;
+ struct vb2_buffer *vb2;

- for (i = 0; i < q->num_buffers; i++)
- if (q->bufs[i]->copied_timestamp &&
- q->bufs[i]->timestamp == timestamp)
- return vb2_get_buffer(q, i);
+ for (i = 0; i < q->num_buffers; i++) {
+ vb2 = vb2_get_buffer(q, i);
+ if (vb2->copied_timestamp &&
+ vb2->timestamp == timestamp)
+ return vb2;
+ }
return NULL;
}
EXPORT_SYMBOL_GPL(vb2_find_buffer);
@@ -664,7 +667,7 @@ int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b)
dprintk(q, 1, "buffer index out of range\n");
return -EINVAL;
}
- vb = q->bufs[b->index];
+ vb = vb2_get_buffer(q, b->index);
ret = __verify_planes_array(vb, b);
if (!ret)
vb2_core_querybuf(q, b->index, b);
diff --git a/drivers/media/platform/amphion/vpu_dbg.c b/drivers/media/platform/amphion/vpu_dbg.c
index 44b830ae01d8..8a423c1f6b55 100644
--- a/drivers/media/platform/amphion/vpu_dbg.c
+++ b/drivers/media/platform/amphion/vpu_dbg.c
@@ -133,7 +133,7 @@ static int vpu_dbg_instance(struct seq_file *s, void *data)

vq = v4l2_m2m_get_src_vq(inst->fh.m2m_ctx);
for (i = 0; i < vq->num_buffers; i++) {
- struct vb2_buffer *vb = vq->bufs[i];
+ struct vb2_buffer *vb = vb2_get_buffer(vq, i);
struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);

if (vb->state == VB2_BUF_STATE_DEQUEUED)
@@ -148,7 +148,7 @@ static int vpu_dbg_instance(struct seq_file *s, void *data)

vq = v4l2_m2m_get_dst_vq(inst->fh.m2m_ctx);
for (i = 0; i < vq->num_buffers; i++) {
- struct vb2_buffer *vb = vq->bufs[i];
+ struct vb2_buffer *vb = vb2_get_buffer(vq, i);
struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);

if (vb->state == VB2_BUF_STATE_DEQUEUED)
diff --git a/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c b/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c
index 969516a940ba..0be07f691d9a 100644
--- a/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c
+++ b/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c
@@ -603,7 +603,7 @@ static int mtk_jpeg_qbuf(struct file *file, void *priv, struct v4l2_buffer *buf)
return -EINVAL;
}

- vb = vq->bufs[buf->index];
+ vb = vb2_get_buffer(vq, buf->index);
jpeg_src_buf = mtk_jpeg_vb2_to_srcbuf(vb);
jpeg_src_buf->bs_size = buf->m.planes[0].bytesused;

diff --git a/drivers/media/platform/mediatek/vcodec/vdec/vdec_vp9_req_lat_if.c b/drivers/media/platform/mediatek/vcodec/vdec/vdec_vp9_req_lat_if.c
index cbb6728b8a40..f5958b6d834a 100644
--- a/drivers/media/platform/mediatek/vcodec/vdec/vdec_vp9_req_lat_if.c
+++ b/drivers/media/platform/mediatek/vcodec/vdec/vdec_vp9_req_lat_if.c
@@ -1701,7 +1701,7 @@ static int vdec_vp9_slice_setup_core_buffer(struct vdec_vp9_slice_instance *inst

/* update internal buffer's width/height */
for (i = 0; i < vq->num_buffers; i++) {
- if (vb == vq->bufs[i]) {
+ if (vb == vb2_get_buffer(vq, i)) {
instance->dpb[i].width = w;
instance->dpb[i].height = h;
break;
diff --git a/drivers/media/test-drivers/visl/visl-dec.c b/drivers/media/test-drivers/visl/visl-dec.c
index 318d675e5668..328016b456ba 100644
--- a/drivers/media/test-drivers/visl/visl-dec.c
+++ b/drivers/media/test-drivers/visl/visl-dec.c
@@ -290,13 +290,14 @@ static void visl_tpg_fill(struct visl_ctx *ctx, struct visl_run *run)
for (i = 0; i < out_q->num_buffers; i++) {
char entry[] = "index: %u, state: %s, request_fd: %d, ";
u32 old_len = len;
- char *q_status = visl_get_vb2_state(out_q->bufs[i]->state);
+ struct vb2_buffer *vb2 = vb2_get_buffer(out_q, i);
+ char *q_status = visl_get_vb2_state(vb2->state);

len += scnprintf(&buf[len], TPG_STR_BUF_SZ - len,
entry, i, q_status,
- to_vb2_v4l2_buffer(out_q->bufs[i])->request_fd);
+ to_vb2_v4l2_buffer(vb2)->request_fd);

- len += visl_fill_bytesused(to_vb2_v4l2_buffer(out_q->bufs[i]),
+ len += visl_fill_bytesused(to_vb2_v4l2_buffer(vb2),
&buf[len],
TPG_STR_BUF_SZ - len);

@@ -342,13 +343,14 @@ static void visl_tpg_fill(struct visl_ctx *ctx, struct visl_run *run)
len = 0;
for (i = 0; i < cap_q->num_buffers; i++) {
u32 old_len = len;
- char *q_status = visl_get_vb2_state(cap_q->bufs[i]->state);
+ struct vb2_buffer *vb2 = vb2_get_buffer(cap_q, i);
+ char *q_status = visl_get_vb2_state(vb2->state);

len += scnprintf(&buf[len], TPG_STR_BUF_SZ - len,
"index: %u, status: %s, timestamp: %llu, is_held: %d",
- cap_q->bufs[i]->index, q_status,
- cap_q->bufs[i]->timestamp,
- to_vb2_v4l2_buffer(cap_q->bufs[i])->is_held);
+ vb2->index, q_status,
+ vb2->timestamp,
+ to_vb2_v4l2_buffer(vb2)->is_held);

tpg_gen_text(&ctx->tpg, basep, line++ * line_height, 16, &buf[old_len]);
frame_dprintk(ctx->dev, run->dst->sequence, "%s", &buf[old_len]);
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index 4b6a9d2ea372..d18c57e7aef0 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -1244,6 +1244,26 @@ static inline struct vb2_buffer *vb2_get_buffer(struct vb2_queue *q,
return NULL;
}

+/**
+ * vb2_set_buffer() - set a buffer to a queue
+ * @q: pointer to &struct vb2_queue with videobuf2 queue.
+ * @vb: pointer to &struct vb2_buffer to be added to the queue.
+ */
+static inline void vb2_set_buffer(struct vb2_queue *q, struct vb2_buffer *vb)
+{
+ q->bufs[vb->index] = vb;
+}
+
+/**
+ * vb2_del_buffer() - remove a buffer from a queue
+ * @q: pointer to &struct vb2_queue with videobuf2 queue.
+ * @vb: pointer to &struct vb2_buffer to be removed from the queue.
+ */
+static inline void vb2_del_buffer(struct vb2_queue *q, struct vb2_buffer *vb)
+{
+ q->bufs[vb->index] = NULL;
+}
+
/*
* The following functions are not part of the vb2 core API, but are useful
* functions for videobuf2-*.
--
2.34.1