Implement iio_dma_buffer_attach_dmabuf(), iio_dma_buffer_detach_dmabuf() and iio_dma_buffer_transfer_dmabuf(), which can then be used by the IIO DMA buffer implementations.
Signed-off-by: Paul Cercueil paul@crapouillou.net
--- v3: Update code to provide the functions that will be used as callbacks for the new IOCTLs. --- drivers/iio/buffer/industrialio-buffer-dma.c | 157 +++++++++++++++++-- include/linux/iio/buffer-dma.h | 26 +++ 2 files changed, 170 insertions(+), 13 deletions(-)
diff --git a/drivers/iio/buffer/industrialio-buffer-dma.c b/drivers/iio/buffer/industrialio-buffer-dma.c index 5610ba67925e..adb64f975064 100644 --- a/drivers/iio/buffer/industrialio-buffer-dma.c +++ b/drivers/iio/buffer/industrialio-buffer-dma.c @@ -14,6 +14,7 @@ #include <linux/poll.h> #include <linux/iio/buffer_impl.h> #include <linux/iio/buffer-dma.h> +#include <linux/dma-buf.h> #include <linux/dma-mapping.h> #include <linux/sizes.h>
@@ -94,14 +95,24 @@ static void iio_buffer_block_release(struct kref *kref) { struct iio_dma_buffer_block *block = container_of(kref, struct iio_dma_buffer_block, kref); + struct iio_dma_buffer_queue *queue = block->queue;
- WARN_ON(block->state != IIO_BLOCK_STATE_DEAD); + WARN_ON(block->fileio && block->state != IIO_BLOCK_STATE_DEAD);
- dma_free_coherent(block->queue->dev, PAGE_ALIGN(block->size), - block->vaddr, block->phys_addr); + mutex_lock(&queue->lock);
- iio_buffer_put(&block->queue->buffer); + if (block->fileio) { + dma_free_coherent(queue->dev, PAGE_ALIGN(block->size), + block->vaddr, block->phys_addr); + queue->num_fileio_blocks--; + } + + queue->num_blocks--; kfree(block); + + mutex_unlock(&queue->lock); + + iio_buffer_put(&queue->buffer); }
static void iio_buffer_block_get(struct iio_dma_buffer_block *block) @@ -163,7 +174,7 @@ static struct iio_dma_buffer_queue *iio_buffer_to_queue(struct iio_buffer *buf) }
static struct iio_dma_buffer_block *iio_dma_buffer_alloc_block( - struct iio_dma_buffer_queue *queue, size_t size) + struct iio_dma_buffer_queue *queue, size_t size, bool fileio) { struct iio_dma_buffer_block *block;
@@ -171,13 +182,16 @@ static struct iio_dma_buffer_block *iio_dma_buffer_alloc_block( if (!block) return NULL;
- block->vaddr = dma_alloc_coherent(queue->dev, PAGE_ALIGN(size), - &block->phys_addr, GFP_KERNEL); - if (!block->vaddr) { - kfree(block); - return NULL; + if (fileio) { + block->vaddr = dma_alloc_coherent(queue->dev, PAGE_ALIGN(size), + &block->phys_addr, GFP_KERNEL); + if (!block->vaddr) { + kfree(block); + return NULL; + } }
+ block->fileio = fileio; block->size = size; block->state = IIO_BLOCK_STATE_DONE; block->queue = queue; @@ -186,6 +200,9 @@ static struct iio_dma_buffer_block *iio_dma_buffer_alloc_block(
iio_buffer_get(&queue->buffer);
+ queue->num_blocks++; + queue->num_fileio_blocks += fileio; + return block; }
@@ -211,6 +228,9 @@ void iio_dma_buffer_block_done(struct iio_dma_buffer_block *block) _iio_dma_buffer_block_done(block); spin_unlock_irqrestore(&queue->list_lock, flags);
+ if (!block->fileio) + iio_buffer_signal_dmabuf_done(block->attach, 0); + iio_buffer_block_put_atomic(block); wake_up_interruptible_poll(&queue->buffer.pollq, EPOLLIN | EPOLLRDNORM); } @@ -237,10 +257,14 @@ void iio_dma_buffer_block_list_abort(struct iio_dma_buffer_queue *queue, list_del(&block->head); block->bytes_used = 0; _iio_dma_buffer_block_done(block); + + if (!block->fileio) + iio_buffer_signal_dmabuf_done(block->attach, -EINTR); iio_buffer_block_put_atomic(block); } spin_unlock_irqrestore(&queue->list_lock, flags);
+ queue->fileio.enabled = false; wake_up_interruptible_poll(&queue->buffer.pollq, EPOLLIN | EPOLLRDNORM); } EXPORT_SYMBOL_GPL(iio_dma_buffer_block_list_abort); @@ -261,6 +285,12 @@ static bool iio_dma_block_reusable(struct iio_dma_buffer_block *block) } }
+static bool iio_dma_buffer_fileio_mode(struct iio_dma_buffer_queue *queue) +{ + return queue->fileio.enabled || + queue->num_blocks == queue->num_fileio_blocks; +} + /** * iio_dma_buffer_request_update() - DMA buffer request_update callback * @buffer: The buffer which to request an update @@ -287,6 +317,12 @@ int iio_dma_buffer_request_update(struct iio_buffer *buffer)
mutex_lock(&queue->lock);
+ queue->fileio.enabled = iio_dma_buffer_fileio_mode(queue); + + /* If DMABUFs were created, disable fileio interface */ + if (!queue->fileio.enabled) + goto out_unlock; + /* Allocations are page aligned */ if (PAGE_ALIGN(queue->fileio.block_size) == PAGE_ALIGN(size)) try_reuse = true; @@ -317,7 +353,7 @@ int iio_dma_buffer_request_update(struct iio_buffer *buffer) block = queue->fileio.blocks[i]; if (block->state == IIO_BLOCK_STATE_DEAD) { /* Could not reuse it */ - iio_buffer_block_put(block); + iio_buffer_block_put_atomic(block); block = NULL; } else { block->size = size; @@ -327,7 +363,7 @@ int iio_dma_buffer_request_update(struct iio_buffer *buffer) }
if (!block) { - block = iio_dma_buffer_alloc_block(queue, size); + block = iio_dma_buffer_alloc_block(queue, size, true); if (!block) { ret = -ENOMEM; goto out_unlock; @@ -363,7 +399,7 @@ static void iio_dma_buffer_fileio_free(struct iio_dma_buffer_queue *queue) for (i = 0; i < ARRAY_SIZE(queue->fileio.blocks); i++) { if (!queue->fileio.blocks[i]) continue; - iio_buffer_block_put(queue->fileio.blocks[i]); + iio_buffer_block_put_atomic(queue->fileio.blocks[i]); queue->fileio.blocks[i] = NULL; } queue->fileio.active_block = NULL; @@ -384,8 +420,12 @@ static void iio_dma_buffer_submit_block(struct iio_dma_buffer_queue *queue,
block->state = IIO_BLOCK_STATE_ACTIVE; iio_buffer_block_get(block); + ret = queue->ops->submit(queue, block); if (ret) { + if (!block->fileio) + iio_buffer_signal_dmabuf_done(block->attach, ret); + /* * This is a bit of a problem and there is not much we can do * other then wait for the buffer to be disabled and re-enabled @@ -588,6 +628,97 @@ size_t iio_dma_buffer_data_available(struct iio_buffer *buf) } EXPORT_SYMBOL_GPL(iio_dma_buffer_data_available);
+struct iio_dma_buffer_block * +iio_dma_buffer_attach_dmabuf(struct iio_buffer *buffer, + struct dma_buf_attachment *attach) +{ + struct iio_dma_buffer_queue *queue = iio_buffer_to_queue(buffer); + struct iio_dma_buffer_block *block; + int err; + + mutex_lock(&queue->lock); + + /* + * If the buffer is enabled and in fileio mode new blocks can't be + * allocated. + */ + if (queue->fileio.enabled) { + err = -EBUSY; + goto err_unlock; + } + + block = iio_dma_buffer_alloc_block(queue, attach->dmabuf->size, false); + if (!block) { + err = -ENOMEM; + goto err_unlock; + } + + block->attach = attach; + + /* Free memory that might be in use for fileio mode */ + iio_dma_buffer_fileio_free(queue); + + mutex_unlock(&queue->lock); + + return block; + +err_unlock: + mutex_unlock(&queue->lock); + return ERR_PTR(err); +} +EXPORT_SYMBOL_GPL(iio_dma_buffer_attach_dmabuf); + +void iio_dma_buffer_detach_dmabuf(struct iio_buffer *buffer, + struct iio_dma_buffer_block *block) +{ + block->state = IIO_BLOCK_STATE_DEAD; + iio_buffer_block_put_atomic(block); +} +EXPORT_SYMBOL_GPL(iio_dma_buffer_detach_dmabuf); + +static int iio_dma_can_enqueue_block(struct iio_dma_buffer_block *block) +{ + struct iio_dma_buffer_queue *queue = block->queue; + + /* If in fileio mode buffers can't be enqueued. */ + if (queue->fileio.enabled) + return -EBUSY; + + switch (block->state) { + case IIO_BLOCK_STATE_QUEUED: + return -EPERM; + case IIO_BLOCK_STATE_DONE: + return 0; + default: + return -EBUSY; + } +} + +int iio_dma_buffer_enqueue_dmabuf(struct iio_buffer *buffer, + struct iio_dma_buffer_block *block, + struct sg_table *sgt, + size_t size, bool cyclic) +{ + struct iio_dma_buffer_queue *queue = iio_buffer_to_queue(buffer); + int ret = 0; + + mutex_lock(&queue->lock); + ret = iio_dma_can_enqueue_block(block); + if (ret < 0) + goto out_mutex_unlock; + + block->bytes_used = size; + block->cyclic = cyclic; + block->sg_table = sgt; + + iio_dma_buffer_enqueue(queue, block); + +out_mutex_unlock: + mutex_unlock(&queue->lock); + return ret; +} +EXPORT_SYMBOL_GPL(iio_dma_buffer_enqueue_dmabuf); + /** * iio_dma_buffer_set_bytes_per_datum() - DMA buffer set_bytes_per_datum callback * @buffer: Buffer to set the bytes-per-datum for diff --git a/include/linux/iio/buffer-dma.h b/include/linux/iio/buffer-dma.h index 18d3702fa95d..7be12a6bff5b 100644 --- a/include/linux/iio/buffer-dma.h +++ b/include/linux/iio/buffer-dma.h @@ -16,6 +16,8 @@ struct iio_dma_buffer_queue; struct iio_dma_buffer_ops; struct device; +struct dma_buf_attachment; +struct sg_table;
/** * enum iio_block_state - State of a struct iio_dma_buffer_block @@ -41,6 +43,8 @@ enum iio_block_state { * @queue: Parent DMA buffer queue * @kref: kref used to manage the lifetime of block * @state: Current state of the block + * @cyclic: True if this is a cyclic buffer + * @fileio: True if this buffer is used for fileio mode */ struct iio_dma_buffer_block { /* May only be accessed by the owner of the block */ @@ -63,6 +67,12 @@ struct iio_dma_buffer_block { * queue->list_lock if the block is not owned by the core. */ enum iio_block_state state; + + bool cyclic; + bool fileio; + + struct dma_buf_attachment *attach; + struct sg_table *sg_table; };
/** @@ -72,6 +82,7 @@ struct iio_dma_buffer_block { * @pos: Read offset in the active block * @block_size: Size of each block * @next_dequeue: index of next block that will be dequeued + * @enabled: Whether the buffer is operating in fileio mode */ struct iio_dma_buffer_queue_fileio { struct iio_dma_buffer_block *blocks[2]; @@ -80,6 +91,7 @@ struct iio_dma_buffer_queue_fileio { size_t block_size;
unsigned int next_dequeue; + bool enabled; };
/** @@ -95,6 +107,8 @@ struct iio_dma_buffer_queue_fileio { * the DMA controller * @incoming: List of buffers on the incoming queue * @active: Whether the buffer is currently active + * @num_blocks: Total number of DMA blocks + * @num_fileio_blocks: Number of DMA blocks for fileio mode * @fileio: FileIO state */ struct iio_dma_buffer_queue { @@ -107,6 +121,8 @@ struct iio_dma_buffer_queue { struct list_head incoming;
bool active; + unsigned int num_blocks; + unsigned int num_fileio_blocks;
struct iio_dma_buffer_queue_fileio fileio; }; @@ -142,4 +158,14 @@ int iio_dma_buffer_init(struct iio_dma_buffer_queue *queue, void iio_dma_buffer_exit(struct iio_dma_buffer_queue *queue); void iio_dma_buffer_release(struct iio_dma_buffer_queue *queue);
+struct iio_dma_buffer_block * +iio_dma_buffer_attach_dmabuf(struct iio_buffer *buffer, + struct dma_buf_attachment *attach); +void iio_dma_buffer_detach_dmabuf(struct iio_buffer *buffer, + struct iio_dma_buffer_block *block); +int iio_dma_buffer_enqueue_dmabuf(struct iio_buffer *buffer, + struct iio_dma_buffer_block *block, + struct sg_table *sgt, + size_t size, bool cyclic); + #endif