From 7b3cc2b1fc2066391e498f3387204908c4eced21 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Thu, 19 Nov 2009 17:10:37 -0700 Subject: async_tx: build-time toggling of async_{syndrome,xor}_val dma support ioat3.2 does not support asynchronous error notifications which makes the driver experience latencies when non-zero pq validate results are expected. Provide a mechanism for turning off async_xor_val and async_syndrome_val via Kconfig. This approach is generally useful for any driver that specifies ASYNC_TX_DISABLE_CHANNEL_SWITCH and would like to force the async_tx api to fall back to the synchronous path for certain operations. Signed-off-by: Dan Williams --- crypto/async_tx/Kconfig | 5 +++++ crypto/async_tx/async_pq.c | 14 +++++++++++--- crypto/async_tx/async_xor.c | 15 ++++++++++++--- 3 files changed, 28 insertions(+), 6 deletions(-) (limited to 'crypto/async_tx') diff --git a/crypto/async_tx/Kconfig b/crypto/async_tx/Kconfig index e5aeb2b79e6..e28e276ac61 100644 --- a/crypto/async_tx/Kconfig +++ b/crypto/async_tx/Kconfig @@ -23,3 +23,8 @@ config ASYNC_RAID6_RECOV select ASYNC_CORE select ASYNC_PQ +config ASYNC_TX_DISABLE_PQ_VAL_DMA + bool + +config ASYNC_TX_DISABLE_XOR_VAL_DMA + bool diff --git a/crypto/async_tx/async_pq.c b/crypto/async_tx/async_pq.c index 6b5cc4fba59..ec87f53d505 100644 --- a/crypto/async_tx/async_pq.c +++ b/crypto/async_tx/async_pq.c @@ -240,6 +240,16 @@ async_gen_syndrome(struct page **blocks, unsigned int offset, int disks, } EXPORT_SYMBOL_GPL(async_gen_syndrome); +static inline struct dma_chan * +pq_val_chan(struct async_submit_ctl *submit, struct page **blocks, int disks, size_t len) +{ + #ifdef CONFIG_ASYNC_TX_DISABLE_PQ_VAL_DMA + return NULL; + #endif + return async_tx_find_channel(submit, DMA_PQ_VAL, NULL, 0, blocks, + disks, len); +} + /** * async_syndrome_val - asynchronously validate a raid6 syndrome * @blocks: source blocks from idx 0..disks-3, P @ disks-2 and Q @ disks-1 @@ -260,9 +270,7 @@ async_syndrome_val(struct page **blocks, unsigned int offset, int disks, size_t len, enum sum_check_flags *pqres, struct page *spare, struct async_submit_ctl *submit) { - struct dma_chan *chan = async_tx_find_channel(submit, DMA_PQ_VAL, - NULL, 0, blocks, disks, - len); + struct dma_chan *chan = pq_val_chan(submit, blocks, disks, len); struct dma_device *device = chan ? chan->device : NULL; struct dma_async_tx_descriptor *tx; unsigned char coefs[disks-2]; diff --git a/crypto/async_tx/async_xor.c b/crypto/async_tx/async_xor.c index 79182dcb91b..079ae8ca590 100644 --- a/crypto/async_tx/async_xor.c +++ b/crypto/async_tx/async_xor.c @@ -234,6 +234,17 @@ static int page_is_zero(struct page *p, unsigned int offset, size_t len) memcmp(a, a + 4, len - 4) == 0); } +static inline struct dma_chan * +xor_val_chan(struct async_submit_ctl *submit, struct page *dest, + struct page **src_list, int src_cnt, size_t len) +{ + #ifdef CONFIG_ASYNC_TX_DISABLE_XOR_VAL_DMA + return NULL; + #endif + return async_tx_find_channel(submit, DMA_XOR_VAL, &dest, 1, src_list, + src_cnt, len); +} + /** * async_xor_val - attempt a xor parity check with a dma engine. * @dest: destination page used if the xor is performed synchronously @@ -255,9 +266,7 @@ async_xor_val(struct page *dest, struct page **src_list, unsigned int offset, int src_cnt, size_t len, enum sum_check_flags *result, struct async_submit_ctl *submit) { - struct dma_chan *chan = async_tx_find_channel(submit, DMA_XOR_VAL, - &dest, 1, src_list, - src_cnt, len); + struct dma_chan *chan = xor_val_chan(submit, dest, src_list, src_cnt, len); struct dma_device *device = chan ? chan->device : NULL; struct dma_async_tx_descriptor *tx = NULL; dma_addr_t *dma_src = NULL; -- cgit v1.2.3-18-g5258