From: Tim Gardner <tim.gardner@xxxxxxxxxxxxx> CC [M] drivers/dma/ioat/prep.o drivers/dma/ioat/prep.c: In function 'ioat_prep_pqxor': drivers/dma/ioat/prep.c:682:1: warning: the frame size of 1048 bytes is larger than 1024 bytes [-Wframe-larger-than=] } ^ drivers/dma/ioat/prep.c: In function 'ioat_prep_pqxor_val': drivers/dma/ioat/prep.c:714:1: warning: the frame size of 1048 bytes is larger than 1024 bytes [-Wframe-larger-than=] } gcc version 5.3.1 20151219 (Ubuntu 5.3.1-4ubuntu1) Cc: Vinod Koul <vinod.koul@xxxxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: Dave Jiang <dave.jiang@xxxxxxxxx> Cc: Prarit Bhargava <prarit@xxxxxxxxxx> Cc: Nicholas Mc Guire <der.herr@xxxxxxx> Cc: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx> Signed-off-by: Tim Gardner <tim.gardner@xxxxxxxxxxxxx> --- v2 - use per CPU static buffers instead of dynamically allocating memory. v3 - Use get_cpu_var/put_cpu_var which implicitly control preeemption. Drop the wrapper function that no longer serves any purpose. drivers/dma/ioat/prep.c | 29 +++++++++++++++++++++++++---- 1 file changed, 25 insertions(+), 4 deletions(-) diff --git a/drivers/dma/ioat/prep.c b/drivers/dma/ioat/prep.c index 6bb4a13..0bd05c8 100644 --- a/drivers/dma/ioat/prep.c +++ b/drivers/dma/ioat/prep.c @@ -21,6 +21,7 @@ #include <linux/dmaengine.h> #include <linux/dma-mapping.h> #include <linux/prefetch.h> +#include <linux/percpu.h> #include "../dmaengine.h" #include "registers.h" #include "hw.h" @@ -655,13 +656,22 @@ ioat_prep_pq_val(struct dma_chan *chan, dma_addr_t *pq, dma_addr_t *src, flags); } +/* + * The scf scratch buffer is too large for an automatic variable, and + * we don't want to take the performance hit for dynamic allocation. + * Therefore, define per CPU buffers and use get_cpu_var()/put_cpu_var() + * to control preemption while the buffer is in use. + */ +static DEFINE_PER_CPU(unsigned char [MAX_SCF], ioat_scf); + struct dma_async_tx_descriptor * ioat_prep_pqxor(struct dma_chan *chan, dma_addr_t dst, dma_addr_t *src, unsigned int src_cnt, size_t len, unsigned long flags) { - unsigned char scf[MAX_SCF]; + unsigned char *scf; dma_addr_t pq[2]; struct ioatdma_chan *ioat_chan = to_ioat_chan(chan); + struct dma_async_tx_descriptor *desc; if (test_bit(IOAT_CHAN_DOWN, &ioat_chan->state)) return NULL; @@ -669,16 +679,21 @@ ioat_prep_pqxor(struct dma_chan *chan, dma_addr_t dst, dma_addr_t *src, if (src_cnt > MAX_SCF) return NULL; + scf = get_cpu_var(ioat_scf); + memset(scf, 0, src_cnt); pq[0] = dst; flags |= DMA_PREP_PQ_DISABLE_Q; pq[1] = dst; /* specify valid address for disabled result */ - return src_cnt_flags(src_cnt, flags) > 8 ? + desc = src_cnt_flags(src_cnt, flags) > 8 ? __ioat_prep_pq16_lock(chan, NULL, pq, src, src_cnt, scf, len, flags) : __ioat_prep_pq_lock(chan, NULL, pq, src, src_cnt, scf, len, flags); + + put_cpu_var(ioat_scf); + return desc; } struct dma_async_tx_descriptor * @@ -686,9 +701,10 @@ ioat_prep_pqxor_val(struct dma_chan *chan, dma_addr_t *src, unsigned int src_cnt, size_t len, enum sum_check_flags *result, unsigned long flags) { - unsigned char scf[MAX_SCF]; + unsigned char *scf; dma_addr_t pq[2]; struct ioatdma_chan *ioat_chan = to_ioat_chan(chan); + struct dma_async_tx_descriptor *desc; if (test_bit(IOAT_CHAN_DOWN, &ioat_chan->state)) return NULL; @@ -696,6 +712,8 @@ ioat_prep_pqxor_val(struct dma_chan *chan, dma_addr_t *src, if (src_cnt > MAX_SCF) return NULL; + scf = get_cpu_var(ioat_scf); + /* the cleanup routine only sets bits on validate failure, it * does not clear bits on validate success... so clear it here */ @@ -706,11 +724,14 @@ ioat_prep_pqxor_val(struct dma_chan *chan, dma_addr_t *src, flags |= DMA_PREP_PQ_DISABLE_Q; pq[1] = pq[0]; /* specify valid address for disabled result */ - return src_cnt_flags(src_cnt, flags) > 8 ? + desc = src_cnt_flags(src_cnt, flags) > 8 ? __ioat_prep_pq16_lock(chan, result, pq, &src[1], src_cnt - 1, scf, len, flags) : __ioat_prep_pq_lock(chan, result, pq, &src[1], src_cnt - 1, scf, len, flags); + + put_cpu_var(ioat_scf); + return desc; } struct dma_async_tx_descriptor * -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html