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 <p...@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 | 24 +++
2 files changed, 168 insertions(+), 13 deletions(-)
diff --git a/drivers/iio/buffer/industrialio-buffer-dma.c
b/drivers/iio/buffer/industrialio-buffer-dma.c
index e14814e0d4c8..422bd784fd1e 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;
}
@@ -223,6 +240,9 @@ 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);
iio_dma_buffer_queue_wake(queue);
}
@@ -249,10 +269,14 @@ 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;
iio_dma_buffer_queue_wake(queue);
}
EXPORT_SYMBOL_GPL(iio_dma_buffer_block_list_abort);
@@ -273,6 +297,12 @@ 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
@@ -299,6 +329,12 @@ 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;
@@ -329,7 +365,7 @@ 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;
@@ -339,7 +375,7 @@ 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;
@@ -391,7 +427,7 @@ 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;
@@ -412,8 +448,12 @@ 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
@@ -645,6 +685,97 @@ 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 490b93f76fa8..e5e5817e99db 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 +43,7 @@ enum iio_block_state {
* @queue: Parent DMA buffer queue
* @kref: kref used to manage the lifetime of block
* @state: Current state of the block
+ * @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 +66,11 @@ struct iio_dma_buffer_block {
* queue->list_lock if the block is not owned by the core.
*/
enum iio_block_state state;
+
+ bool fileio;
+
+ struct dma_buf_attachment *attach;
+ struct sg_table *sg_table;
};
/**
@@ -72,6 +80,7 @@ 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 +89,7 @@ struct iio_dma_buffer_queue_fileio {
size_t block_size;
unsigned int next_dequeue;
+ bool enabled;
};
/**
@@ -95,6 +105,8 @@ 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 +119,8 @@ 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;
};
@@ -149,4 +163,14 @@ static inline size_t iio_dma_buffer_space_available(struct
iio_buffer *buffer)
return iio_dma_buffer_data_available(buffer);
}
+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
--
2.39.2
