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media: core: Add bitmap manage bufs array entries 

Add a bitmap field to know which of bufs array entries are
used or not.
Remove no more used num_buffers field from queue structure.
Use bitmap_find_next_zero_area() to find the first possible
range when creating new buffers to fill the gaps.
If no suitable range is found try to allocate less buffers
than requested.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
Acked-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
This commit is contained in:
Benjamin Gaignard 2024-03-14 16:32:22 +01:00 committed by Hans Verkuil
parent 6e423b75d0
commit a286b0837e
2 changed files with 64 additions and 25 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

71
drivers/media/common/videobuf2/videobuf2-core.c
View File

@ -421,11 +421,12 @@ static void init_buffer_cache_hints(struct vb2_queue *q, struct vb2_buffer *vb)
*/
static void vb2_queue_add_buffer(struct vb2_queue *q, struct vb2_buffer *vb, unsigned int index)
{
WARN_ON(index >= q->max_num_buffers || q->bufs[index] || vb->vb2_queue);
WARN_ON(index >= q->max_num_buffers || test_bit(index, q->bufs_bitmap) || vb->vb2_queue);
q->bufs[index] = vb;
vb->index = index;
vb->vb2_queue = q;
set_bit(index, q->bufs_bitmap);
}
/**
@ -434,6 +435,7 @@ static void vb2_queue_add_buffer(struct vb2_queue *q, struct vb2_buffer *vb, uns
*/
static void vb2_queue_remove_buffer(struct vb2_buffer *vb)
{
clear_bit(vb->index, vb->vb2_queue->bufs_bitmap);
vb->vb2_queue->bufs[vb->index] = NULL;
vb->vb2_queue = NULL;
}
@ -452,9 +454,9 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
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;
struct vb2_buffer *vb;
unsigned long index = q->max_num_buffers;
int ret;
/*
@ -462,9 +464,25 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
* in the queue is below q->max_num_buffers
*/
num_buffers = min_t(unsigned int, num_buffers,
q->max_num_buffers - q_num_buffers);
q->max_num_buffers - vb2_get_num_buffers(q));
*first_index = q_num_buffers;
while (num_buffers) {
index = bitmap_find_next_zero_area(q->bufs_bitmap, q->max_num_buffers,
0, num_buffers, 0);
if (index < q->max_num_buffers)
break;
/* Try to find free space for less buffers */
num_buffers--;
}
/* If there is no space left to allocate buffers return 0 to indicate the error */
if (!num_buffers) {
*first_index = 0;
return 0;
}
*first_index = index;
for (buffer = 0; buffer < num_buffers; ++buffer) {
/* Allocate vb2 buffer structures */
@ -484,7 +502,7 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
vb->planes[plane].min_length = plane_sizes[plane];
}
vb2_queue_add_buffer(q, vb, q_num_buffers + buffer);
vb2_queue_add_buffer(q, vb, index++);
call_void_bufop(q, init_buffer, vb);
/* Allocate video buffer memory for the MMAP type */
@ -664,7 +682,6 @@ static void __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
kfree(vb);
}
q->num_buffers -= buffers;
if (!vb2_get_num_buffers(q)) {
q->memory = VB2_MEMORY_UNKNOWN;
INIT_LIST_HEAD(&q->queued_list);
@ -818,6 +835,32 @@ static bool verify_coherency_flags(struct vb2_queue *q, bool non_coherent_mem)
return true;
}
static int vb2_core_allocated_buffers_storage(struct vb2_queue *q)
{
if (!q->bufs)
q->bufs = kcalloc(q->max_num_buffers, sizeof(*q->bufs), GFP_KERNEL);
if (!q->bufs)
return -ENOMEM;
if (!q->bufs_bitmap)
q->bufs_bitmap = bitmap_zalloc(q->max_num_buffers, GFP_KERNEL);
if (!q->bufs_bitmap) {
kfree(q->bufs);
q->bufs = NULL;
return -ENOMEM;
}
return 0;
}
static void vb2_core_free_buffers_storage(struct vb2_queue *q)
{
kfree(q->bufs);
q->bufs = NULL;
bitmap_free(q->bufs_bitmap);
q->bufs_bitmap = NULL;
}
int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
unsigned int flags, unsigned int *count)
{
@ -879,10 +922,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
* in the queue_setup op.
*/
mutex_lock(&q->mmap_lock);
if (!q->bufs)
q->bufs = kcalloc(q->max_num_buffers, sizeof(*q->bufs), GFP_KERNEL);
if (!q->bufs)
ret = -ENOMEM;
ret = vb2_core_allocated_buffers_storage(q);
q->memory = memory;
mutex_unlock(&q->mmap_lock);
if (ret)
@ -954,7 +994,6 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
}
mutex_lock(&q->mmap_lock);
q->num_buffers = allocated_buffers;
if (ret < 0) {
/*
@ -982,6 +1021,7 @@ error:
mutex_lock(&q->mmap_lock);
q->memory = VB2_MEMORY_UNKNOWN;
mutex_unlock(&q->mmap_lock);
vb2_core_free_buffers_storage(q);
return ret;
}
EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
@ -1015,11 +1055,8 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
* value in the queue_setup op.
*/
mutex_lock(&q->mmap_lock);
ret = vb2_core_allocated_buffers_storage(q);
q->memory = memory;
if (!q->bufs)
q->bufs = kcalloc(q->max_num_buffers, sizeof(*q->bufs), GFP_KERNEL);
if (!q->bufs)
ret = -ENOMEM;
mutex_unlock(&q->mmap_lock);
if (ret)
return ret;
@ -1082,7 +1119,6 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
}
mutex_lock(&q->mmap_lock);
q->num_buffers += allocated_buffers;
if (ret < 0) {
/*
@ -2583,8 +2619,7 @@ void vb2_core_queue_release(struct vb2_queue *q)
__vb2_queue_cancel(q);
mutex_lock(&q->mmap_lock);
__vb2_queue_free(q, vb2_get_num_buffers(q));
kfree(q->bufs);
q->bufs = NULL;
vb2_core_free_buffers_storage(q);
q->is_busy = 0;
mutex_unlock(&q->mmap_lock);
}

18
include/media/videobuf2-core.h
View File

@ -346,8 +346,8 @@ struct vb2_buffer {
* describes the requested number of planes and sizes\[\]
* contains the requested plane sizes. In this case
* \*num_buffers are being allocated additionally to
* q->num_buffers. If either \*num_planes or the requested
* sizes are invalid callback must return %-EINVAL.
* the buffers already allocated. If either \*num_planes
* or the requested sizes are invalid callback must return %-EINVAL.
* @wait_prepare: release any locks taken while calling vb2 functions;
* it is called before an ioctl needs to wait for a new
* buffer to arrive; required to avoid a deadlock in
@ -571,8 +571,9 @@ struct vb2_buf_ops {
* @mmap_lock: private mutex used when buffers are allocated/freed/mmapped
* @memory: current memory type used
* @dma_dir: DMA mapping direction.
* @bufs: videobuf2 buffer structures
* @num_buffers: number of allocated/used buffers
* @bufs: videobuf2 buffer structures. If it is non-NULL then
* bufs_bitmap is also non-NULL.
* @bufs_bitmap: bitmap tracking whether each bufs[] entry is used
* @max_num_buffers: upper limit of number of allocated/used buffers.
* If set to 0 v4l2 core will change it VB2_MAX_FRAME
* for backward compatibility.
@ -643,7 +644,7 @@ struct vb2_queue {
unsigned int memory;
enum dma_data_direction dma_dir;
struct vb2_buffer **bufs;
unsigned int num_buffers;
unsigned long *bufs_bitmap;
unsigned int max_num_buffers;
struct list_head queued_list;
@ -1173,7 +1174,10 @@ static inline bool vb2_fileio_is_active(struct vb2_queue *q)
*/
static inline unsigned int vb2_get_num_buffers(struct vb2_queue *q)
{
return q->num_buffers;
if (q->bufs_bitmap)
return bitmap_weight(q->bufs_bitmap, q->max_num_buffers);
return 0;
}
/**
@ -1282,7 +1286,7 @@ static inline struct vb2_buffer *vb2_get_buffer(struct vb2_queue *q,
if (index >= q->max_num_buffers)
return NULL;
if (index < q->num_buffers)
if (test_bit(index, q->bufs_bitmap))
return q->bufs[index];
return NULL;
}