Message ID | 1505811161-25246-3-git-send-email-chenhc@lemote.com (mailing list archive) |
---|---|
State | Changes Requested |
Headers | show |
Hi Huacai, [auto build test ERROR on linus/master] [also build test ERROR on v4.14-rc1 next-20170922] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system] url: https://github.com/0day-ci/linux/commits/Huacai-Chen/dma-mapping-Introduce-device_is_coherent-as-a-helper/20170920-204740 config: m68k-sun3_defconfig (attached as .config) compiler: m68k-linux-gcc (GCC) 4.9.0 reproduce: wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # save the attached .config to linux build tree make.cross ARCH=m68k All errors (new ones prefixed by >>): drivers/scsi/scsi_lib.c: In function '__scsi_init_queue': >> drivers/scsi/scsi_lib.c:2139:2: error: implicit declaration of function 'dma_get_cache_alignment' [-Werror=implicit-function-declaration] blk_queue_dma_alignment(q, max(4, dma_get_cache_alignment(dev)) - 1); ^ cc1: some warnings being treated as errors vim +/dma_get_cache_alignment +2139 drivers/scsi/scsi_lib.c 2103 2104 void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q) 2105 { 2106 struct device *dev = shost->dma_dev; 2107 2108 queue_flag_set_unlocked(QUEUE_FLAG_SCSI_PASSTHROUGH, q); 2109 2110 /* 2111 * this limit is imposed by hardware restrictions 2112 */ 2113 blk_queue_max_segments(q, min_t(unsigned short, shost->sg_tablesize, 2114 SG_MAX_SEGMENTS)); 2115 2116 if (scsi_host_prot_dma(shost)) { 2117 shost->sg_prot_tablesize = 2118 min_not_zero(shost->sg_prot_tablesize, 2119 (unsigned short)SCSI_MAX_PROT_SG_SEGMENTS); 2120 BUG_ON(shost->sg_prot_tablesize < shost->sg_tablesize); 2121 blk_queue_max_integrity_segments(q, shost->sg_prot_tablesize); 2122 } 2123 2124 blk_queue_max_hw_sectors(q, shost->max_sectors); 2125 blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost)); 2126 blk_queue_segment_boundary(q, shost->dma_boundary); 2127 dma_set_seg_boundary(dev, shost->dma_boundary); 2128 2129 blk_queue_max_segment_size(q, dma_get_max_seg_size(dev)); 2130 2131 if (!shost->use_clustering) 2132 q->limits.cluster = 0; 2133 2134 /* 2135 * set a reasonable default alignment on word/cacheline boundaries: 2136 * the host and device may alter it using 2137 * blk_queue_update_dma_alignment() later. 2138 */ > 2139 blk_queue_dma_alignment(q, max(4, dma_get_cache_alignment(dev)) - 1); 2140 } 2141 EXPORT_SYMBOL_GPL(__scsi_init_queue); 2142 --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 9cf6a80..19abc2e 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -2132,11 +2132,11 @@ void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q) q->limits.cluster = 0; /* - * set a reasonable default alignment on word boundaries: the - * host and device may alter it using + * set a reasonable default alignment on word/cacheline boundaries: + * the host and device may alter it using * blk_queue_update_dma_alignment() later. */ - blk_queue_dma_alignment(q, 0x03); + blk_queue_dma_alignment(q, max(4, dma_get_cache_alignment(dev)) - 1); } EXPORT_SYMBOL_GPL(__scsi_init_queue);
In non-coherent DMA mode, kernel uses cache flushing operations to maintain I/O coherency, so scsi's block queue should be aligned to ARCH_DMA_MINALIGN. Otherwise, it will cause data corruption, at least on MIPS: Step 1, dma_map_single Step 2, cache_invalidate (no writeback) Step 3, dma_from_device Step 4, dma_unmap_single If a DMA buffer and a kernel structure share a same cache line, and if the kernel structure has dirty data, cache_invalidate (no writeback) will cause data lost. Cc: stable@vger.kernel.org Signed-off-by: Huacai Chen <chenhc@lemote.com> --- drivers/scsi/scsi_lib.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)