@@ -459,6 +459,87 @@ static struct fsl_desc_sw *fsl_dma_alloc_descriptor(struct fsldma_chan *chan)
}
/**
+ * fsldma_clean_completed_descriptor - free all descriptors which
+ * has been completed and acked
+ * @chan: Freescale DMA channel
+ *
+ * This function is used on all completed and acked descriptors.
+ * All descriptors should only be freed in this function.
+ */
+static void fsldma_clean_completed_descriptor(struct fsldma_chan *chan)
+{
+ struct fsl_desc_sw *desc, *_desc;
+
+ /* Run the callback for each descriptor, in order */
+ list_for_each_entry_safe(desc, _desc, &chan->ld_completed, node)
+ if (async_tx_test_ack(&desc->async_tx))
+ fsl_dma_free_descriptor(chan, desc);
+}
+
+/**
+ * fsldma_run_tx_complete_actions - cleanup a single link descriptor
+ * @chan: Freescale DMA channel
+ * @desc: descriptor to cleanup and free
+ * @cookie: Freescale DMA transaction identifier
+ *
+ * This function is used on a descriptor which has been executed by the DMA
+ * controller. It will run any callbacks, submit any dependencies.
+ */
+static dma_cookie_t fsldma_run_tx_complete_actions(struct fsldma_chan *chan,
+ struct fsl_desc_sw *desc, dma_cookie_t cookie)
+{
+ struct dma_async_tx_descriptor *txd = &desc->async_tx;
+
+ BUG_ON(txd->cookie < 0);
+
+ if (txd->cookie > 0) {
+ cookie = txd->cookie;
+
+ /* Run the link descriptor callback function */
+ if (txd->callback) {
+ chan_dbg(chan, "LD %p callback\n", desc);
+ txd->callback(txd->callback_param);
+ }
+ }
+
+ /* Run any dependencies */
+ dma_run_dependencies(txd);
+
+ return cookie;
+}
+
+/**
+ * fsldma_clean_running_descriptor - move the completed descriptor from
+ * ld_running to ld_completed
+ * @chan: Freescale DMA channel
+ * @desc: the descriptor which is completed
+ *
+ * Free the descriptor directly if acked by async_tx api, or move it to
+ * queue ld_completed.
+ */
+static void fsldma_clean_running_descriptor(struct fsldma_chan *chan,
+ struct fsl_desc_sw *desc)
+{
+ /* Remove from the list of transactions */
+ list_del(&desc->node);
+
+ /*
+ * the client is allowed to attach dependent operations
+ * until 'ack' is set
+ */
+ if (!async_tx_test_ack(&desc->async_tx)) {
+ /*
+ * Move this descriptor to the list of descriptors which is
+ * completed, but still awaiting the 'ack' bit to be set.
+ */
+ list_add_tail(&desc->node, &chan->ld_completed);
+ return;
+ }
+
+ dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
+}
+
+/**
* fsl_chan_xfer_ld_queue - transfer any pending transactions
* @chan : Freescale DMA channel
*
@@ -526,30 +607,58 @@ static void fsl_chan_xfer_ld_queue(struct fsldma_chan *chan)
}
/**
- * fsldma_cleanup_descriptor - cleanup and free a single link descriptor
+ * fsldma_cleanup_descriptors - cleanup link descriptors which are completed
+ * and move them to ld_completed to free until flag 'ack' is set
* @chan: Freescale DMA channel
- * @desc: descriptor to cleanup and free
*
- * This function is used on a descriptor which has been executed by the DMA
- * controller. It will run any callbacks, submit any dependencies, and then
- * free the descriptor.
+ * This function is used on descriptors which have been executed by the DMA
+ * controller. It will run any callbacks, submit any dependencies, then
+ * free these descriptors if flag 'ack' is set.
*/
-static void fsldma_cleanup_descriptor(struct fsldma_chan *chan,
- struct fsl_desc_sw *desc)
+static void fsldma_cleanup_descriptors(struct fsldma_chan *chan)
{
- struct dma_async_tx_descriptor *txd = &desc->async_tx;
+ struct fsl_desc_sw *desc, *_desc;
+ dma_cookie_t cookie = 0;
+ dma_addr_t curr_phys = get_cdar(chan);
+ int seen_current = 0;
+
+ fsldma_clean_completed_descriptor(chan);
+
+ /* Run the callback for each descriptor, in order */
+ list_for_each_entry_safe(desc, _desc, &chan->ld_running, node) {
+ /*
+ * do not advance past the current descriptor loaded into the
+ * hardware channel, subsequent descriptors are either in
+ * process or have not been submitted
+ */
+ if (seen_current)
+ break;
+
+ /*
+ * stop the search if we reach the current descriptor and the
+ * channel is busy
+ */
+ if (desc->async_tx.phys == curr_phys) {
+ seen_current = 1;
+ if (!dma_is_idle(chan))
+ break;
+ }
+
+ cookie = fsldma_run_tx_complete_actions(chan, desc, cookie);
- /* Run the link descriptor callback function */
- if (txd->callback) {
- chan_dbg(chan, "LD %p callback\n", desc);
- txd->callback(txd->callback_param);
+ fsldma_clean_running_descriptor(chan, desc);
}
- /* Run any dependencies */
- dma_run_dependencies(txd);
+ /*
+ * Start any pending transactions automatically
+ *
+ * In the ideal case, we keep the DMA controller busy while we go
+ * ahead and free the descriptors below.
+ */
+ fsl_chan_xfer_ld_queue(chan);
- dma_descriptor_unmap(txd);
- fsl_dma_free_descriptor(chan, desc);
+ if (cookie > 0)
+ chan->common.completed_cookie = cookie;
}
/**
@@ -620,8 +729,10 @@ static void fsl_dma_free_chan_resources(struct dma_chan *dchan)
chan_dbg(chan, "free all channel resources\n");
spin_lock_irqsave(&chan->desc_lock, flags);
+ fsldma_cleanup_descriptors(chan);
fsldma_free_desc_list(chan, &chan->ld_pending);
fsldma_free_desc_list(chan, &chan->ld_running);
+ fsldma_free_desc_list(chan, &chan->ld_completed);
spin_unlock_irqrestore(&chan->desc_lock, flags);
dma_pool_destroy(chan->desc_pool);
@@ -859,6 +970,7 @@ static int fsl_dma_device_control(struct dma_chan *dchan,
/* Remove and free all of the descriptors in the LD queue */
fsldma_free_desc_list(chan, &chan->ld_pending);
fsldma_free_desc_list(chan, &chan->ld_running);
+ fsldma_free_desc_list(chan, &chan->ld_completed);
chan->idle = true;
spin_unlock_irqrestore(&chan->desc_lock, flags);
@@ -918,6 +1030,17 @@ static enum dma_status fsl_tx_status(struct dma_chan *dchan,
dma_cookie_t cookie,
struct dma_tx_state *txstate)
{
+ struct fsldma_chan *chan = to_fsl_chan(dchan);
+ enum dma_status ret;
+
+ ret = dma_cookie_status(dchan, cookie, txstate);
+ if (ret == DMA_COMPLETE)
+ return ret;
+
+ spin_lock_bh(&chan->desc_lock);
+ fsldma_cleanup_descriptors(chan);
+ spin_unlock_bh(&chan->desc_lock);
+
return dma_cookie_status(dchan, cookie, txstate);
}
@@ -995,52 +1118,19 @@ static irqreturn_t fsldma_chan_irq(int irq, void *data)
static void dma_do_tasklet(unsigned long data)
{
struct fsldma_chan *chan = (struct fsldma_chan *)data;
- struct fsl_desc_sw *desc, *_desc;
- LIST_HEAD(ld_cleanup);
unsigned long flags;
chan_dbg(chan, "tasklet entry\n");
spin_lock_irqsave(&chan->desc_lock, flags);
- /* update the cookie if we have some descriptors to cleanup */
- if (!list_empty(&chan->ld_running)) {
- dma_cookie_t cookie;
-
- desc = to_fsl_desc(chan->ld_running.prev);
- cookie = desc->async_tx.cookie;
- dma_cookie_complete(&desc->async_tx);
-
- chan_dbg(chan, "completed_cookie=%d\n", cookie);
- }
-
- /*
- * move the descriptors to a temporary list so we can drop the lock
- * during the entire cleanup operation
- */
- list_splice_tail_init(&chan->ld_running, &ld_cleanup);
-
/* the hardware is now idle and ready for more */
chan->idle = true;
- /*
- * Start any pending transactions automatically
- *
- * In the ideal case, we keep the DMA controller busy while we go
- * ahead and free the descriptors below.
- */
- fsl_chan_xfer_ld_queue(chan);
- spin_unlock_irqrestore(&chan->desc_lock, flags);
+ /* Run all cleanup for descriptors which have been completed */
+ fsldma_cleanup_descriptors(chan);
- /* Run the callback for each descriptor, in order */
- list_for_each_entry_safe(desc, _desc, &ld_cleanup, node) {
-
- /* Remove from the list of transactions */
- list_del(&desc->node);
-
- /* Run all cleanup for this descriptor */
- fsldma_cleanup_descriptor(chan, desc);
- }
+ spin_unlock_irqrestore(&chan->desc_lock, flags);
chan_dbg(chan, "tasklet exit\n");
}
@@ -1224,6 +1314,7 @@ static int fsl_dma_chan_probe(struct fsldma_device *fdev,
spin_lock_init(&chan->desc_lock);
INIT_LIST_HEAD(&chan->ld_pending);
INIT_LIST_HEAD(&chan->ld_running);
+ INIT_LIST_HEAD(&chan->ld_completed);
chan->idle = true;
chan->common.device = &fdev->common;
@@ -138,8 +138,21 @@ struct fsldma_chan {
char name[8]; /* Channel name */
struct fsldma_chan_regs __iomem *regs;
spinlock_t desc_lock; /* Descriptor operation lock */
- struct list_head ld_pending; /* Link descriptors queue */
- struct list_head ld_running; /* Link descriptors queue */
+ /*
+ * Descriptors which are queued to run, but have not yet been
+ * submitted to the hardware for execution
+ */
+ struct list_head ld_pending;
+ /*
+ * Descriptors which are currently being executed by the hardware
+ */
+ struct list_head ld_running;
+ /*
+ * Descriptors which have finished execution by the hardware. These
+ * descriptors have already had their cleanup actions run. They are
+ * waiting for the ACK bit to be set by the async_tx API.
+ */
+ struct list_head ld_completed; /* Link descriptors queue */
struct dma_chan common; /* DMA common channel */
struct dma_pool *desc_pool; /* Descriptors pool */
struct device *dev; /* Channel device */