Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-24 21:21:41 +00:00
Code Issues Packages Projects Releases Wiki Activity

iio: buffer-dmaengine: Support new DMABUF based userspace API

Browse Source 
Use the functions provided by the buffer-dma core to implement the
DMABUF userspace API in the buffer-dmaengine IIO buffer implementation.

Since we want to be able to transfer an arbitrary number of bytes and
not necesarily the full DMABUF, the associated scatterlist is converted
to an array of DMA addresses + lengths, which is then passed to
dmaengine_prep_slave_dma_array().

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Co-developed-by: Nuno Sa <nuno.sa@analog.com>
Signed-off-by: Nuno Sa <nuno.sa@analog.com>
Link: https://patch.msgid.link/20240620122726.41232-6-paul@crapouillou.net
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Paul Cercueil 2024-06-20 14:27:24 +02:00 committed by Jonathan Cameron
parent d85318900c
commit 7a86d46998
1 changed files with 54 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

64
drivers/iio/buffer/industrialio-buffer-dmaengine.c
View File

@ -65,25 +65,62 @@ static int iio_dmaengine_buffer_submit_block(struct iio_dma_buffer_queue *queue,
iio_buffer_to_dmaengine_buffer(&queue->buffer);
struct dma_async_tx_descriptor *desc;
enum dma_transfer_direction dma_dir;
struct scatterlist *sgl;
struct dma_vec *vecs;
size_t max_size;
dma_cookie_t cookie;
size_t len_total;
unsigned int i;
int nents;
max_size = min(block->size, dmaengine_buffer->max_size);
max_size = round_down(max_size, dmaengine_buffer->align);
if (queue->buffer.direction == IIO_BUFFER_DIRECTION_IN) {
block->bytes_used = max_size;
if (queue->buffer.direction == IIO_BUFFER_DIRECTION_IN)
dma_dir = DMA_DEV_TO_MEM;
} else {
else
dma_dir = DMA_MEM_TO_DEV;
if (block->sg_table) {
sgl = block->sg_table->sgl;
nents = sg_nents_for_len(sgl, block->bytes_used);
if (nents < 0)
return nents;
vecs = kmalloc_array(nents, sizeof(*vecs), GFP_ATOMIC);
if (!vecs)
return -ENOMEM;
len_total = block->bytes_used;
for (i = 0; i < nents; i++) {
vecs[i].addr = sg_dma_address(sgl);
vecs[i].len = min(sg_dma_len(sgl), len_total);
len_total -= vecs[i].len;
sgl = sg_next(sgl);
}
desc = dmaengine_prep_peripheral_dma_vec(dmaengine_buffer->chan,
vecs, nents, dma_dir,
DMA_PREP_INTERRUPT);
kfree(vecs);
} else {
max_size = min(block->size, dmaengine_buffer->max_size);
max_size = round_down(max_size, dmaengine_buffer->align);
if (queue->buffer.direction == IIO_BUFFER_DIRECTION_IN)
block->bytes_used = max_size;
if (!block->bytes_used || block->bytes_used > max_size)
return -EINVAL;
desc = dmaengine_prep_slave_single(dmaengine_buffer->chan,
block->phys_addr,
block->bytes_used,
dma_dir,
DMA_PREP_INTERRUPT);
}
if (!block->bytes_used || block->bytes_used > max_size)
return -EINVAL;
desc = dmaengine_prep_slave_single(dmaengine_buffer->chan,
block->phys_addr, block->bytes_used, dma_dir,
DMA_PREP_INTERRUPT);
if (!desc)
return -ENOMEM;
@ -133,6 +170,13 @@ static const struct iio_buffer_access_funcs iio_dmaengine_buffer_ops = {
.space_available = iio_dma_buffer_usage,
.release = iio_dmaengine_buffer_release,
.enqueue_dmabuf = iio_dma_buffer_enqueue_dmabuf,
.attach_dmabuf = iio_dma_buffer_attach_dmabuf,
.detach_dmabuf = iio_dma_buffer_detach_dmabuf,
.lock_queue = iio_dma_buffer_lock_queue,
.unlock_queue = iio_dma_buffer_unlock_queue,
.modes = INDIO_BUFFER_HARDWARE,
.flags = INDIO_BUFFER_FLAG_FIXED_WATERMARK,
};