diff options
Diffstat (limited to 'drivers/dma')
| -rw-r--r-- | drivers/dma/Kconfig | 2 | ||||
| -rw-r--r-- | drivers/dma/dmaengine.c | 84 | ||||
| -rw-r--r-- | drivers/dma/iop-adma.c | 3 | ||||
| -rw-r--r-- | drivers/dma/mv_xor.c | 3 |
4 files changed, 86 insertions, 6 deletions
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig index 904e57558bb5..e34b06420816 100644 --- a/drivers/dma/Kconfig +++ b/drivers/dma/Kconfig @@ -33,7 +33,6 @@ config INTEL_IOATDMA config INTEL_IOP_ADMA tristate "Intel IOP ADMA support" depends on ARCH_IOP32X || ARCH_IOP33X || ARCH_IOP13XX - select ASYNC_CORE select DMA_ENGINE help Enable support for the Intel(R) IOP Series RAID engines. @@ -59,7 +58,6 @@ config FSL_DMA config MV_XOR bool "Marvell XOR engine support" depends on PLAT_ORION - select ASYNC_CORE select DMA_ENGINE ---help--- Enable support for the Marvell XOR engine. diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index 657996517374..b9008932a8f3 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -626,6 +626,90 @@ void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx, } EXPORT_SYMBOL(dma_async_tx_descriptor_init); +/* dma_wait_for_async_tx - spin wait for a transaction to complete + * @tx: in-flight transaction to wait on + * + * This routine assumes that tx was obtained from a call to async_memcpy, + * async_xor, async_memset, etc which ensures that tx is "in-flight" (prepped + * and submitted). Walking the parent chain is only meant to cover for DMA + * drivers that do not implement the DMA_INTERRUPT capability and may race with + * the driver's descriptor cleanup routine. + */ +enum dma_status +dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx) +{ + enum dma_status status; + struct dma_async_tx_descriptor *iter; + struct dma_async_tx_descriptor *parent; + + if (!tx) + return DMA_SUCCESS; + + WARN_ONCE(tx->parent, "%s: speculatively walking dependency chain for" + " %s\n", __func__, dev_name(&tx->chan->dev)); + + /* poll through the dependency chain, return when tx is complete */ + do { + iter = tx; + + /* find the root of the unsubmitted dependency chain */ + do { + parent = iter->parent; + if (!parent) + break; + else + iter = parent; + } while (parent); + + /* there is a small window for ->parent == NULL and + * ->cookie == -EBUSY + */ + while (iter->cookie == -EBUSY) + cpu_relax(); + + status = dma_sync_wait(iter->chan, iter->cookie); + } while (status == DMA_IN_PROGRESS || (iter != tx)); + + return status; +} +EXPORT_SYMBOL_GPL(dma_wait_for_async_tx); + +/* dma_run_dependencies - helper routine for dma drivers to process + * (start) dependent operations on their target channel + * @tx: transaction with dependencies + */ +void dma_run_dependencies(struct dma_async_tx_descriptor *tx) +{ + struct dma_async_tx_descriptor *dep = tx->next; + struct dma_async_tx_descriptor *dep_next; + struct dma_chan *chan; + + if (!dep) + return; + + chan = dep->chan; + + /* keep submitting up until a channel switch is detected + * in that case we will be called again as a result of + * processing the interrupt from async_tx_channel_switch + */ + for (; dep; dep = dep_next) { + spin_lock_bh(&dep->lock); + dep->parent = NULL; + dep_next = dep->next; + if (dep_next && dep_next->chan == chan) + dep->next = NULL; /* ->next will be submitted */ + else + dep_next = NULL; /* submit current dep and terminate */ + spin_unlock_bh(&dep->lock); + + dep->tx_submit(dep); + } + + chan->device->device_issue_pending(chan); +} +EXPORT_SYMBOL_GPL(dma_run_dependencies); + static int __init dma_bus_init(void) { mutex_init(&dma_list_mutex); diff --git a/drivers/dma/iop-adma.c b/drivers/dma/iop-adma.c index 6be317262200..be9ea9f88805 100644 --- a/drivers/dma/iop-adma.c +++ b/drivers/dma/iop-adma.c @@ -24,7 +24,6 @@ #include <linux/init.h> #include <linux/module.h> -#include <linux/async_tx.h> #include <linux/delay.h> #include <linux/dma-mapping.h> #include <linux/spinlock.h> @@ -116,7 +115,7 @@ iop_adma_run_tx_complete_actions(struct iop_adma_desc_slot *desc, } /* run dependent operations */ - async_tx_run_dependencies(&desc->async_tx); + dma_run_dependencies(&desc->async_tx); return cookie; } diff --git a/drivers/dma/mv_xor.c b/drivers/dma/mv_xor.c index bcda17426411..3f46df3390c7 100644 --- a/drivers/dma/mv_xor.c +++ b/drivers/dma/mv_xor.c @@ -18,7 +18,6 @@ #include <linux/init.h> #include <linux/module.h> -#include <linux/async_tx.h> #include <linux/delay.h> #include <linux/dma-mapping.h> #include <linux/spinlock.h> @@ -340,7 +339,7 @@ mv_xor_run_tx_complete_actions(struct mv_xor_desc_slot *desc, } /* run dependent operations */ - async_tx_run_dependencies(&desc->async_tx); + dma_run_dependencies(&desc->async_tx); return cookie; } |
