From: Akinobu Mita Date: Wed, 26 Feb 2014 13:57:02 +0000 (+0900) Subject: [SCSI] scsi_debug: prepare to enable clustering X-Git-Tag: v4.14-rc1~7808^2~26 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=be4e11be99dbb36308760595ee848ef51713b4b0;p=platform%2Fkernel%2Flinux-rpi.git [SCSI] scsi_debug: prepare to enable clustering Currently, clustering support for scsi_debug is disabled. This is because there are for_each_sg() loops which assume that each sg list element is consisted with a single page. But enabling clustering support, each sg list element for scsi commands can be consisted with multiple pages. This replaces these for_each_sg() loops with sg mapping iterator which is capable of handling each sg list element is consisted with multiple pages. Signed-off-by: Akinobu Mita Reviewed-by: Douglas Gilbert Reviewed-by: Martin K. Petersen Signed-off-by: James Bottomley --- diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c index a102519..004b98566 100644 --- a/drivers/scsi/scsi_debug.c +++ b/drivers/scsi/scsi_debug.c @@ -1789,23 +1789,27 @@ static int dif_verify(struct sd_dif_tuple *sdt, const void *data, static void dif_copy_prot(struct scsi_cmnd *SCpnt, sector_t sector, unsigned int sectors, bool read) { - unsigned int i, resid; - struct scatterlist *psgl; + size_t resid; void *paddr; const void *dif_store_end = dif_storep + sdebug_store_sectors; + struct sg_mapping_iter miter; /* Bytes of protection data to copy into sgl */ resid = sectors * sizeof(*dif_storep); - scsi_for_each_prot_sg(SCpnt, psgl, scsi_prot_sg_count(SCpnt), i) { - int len = min(psgl->length, resid); + sg_miter_start(&miter, scsi_prot_sglist(SCpnt), + scsi_prot_sg_count(SCpnt), SG_MITER_ATOMIC | + (read ? SG_MITER_TO_SG : SG_MITER_FROM_SG)); + + while (sg_miter_next(&miter) && resid > 0) { + size_t len = min(miter.length, resid); void *start = dif_store(sector); - int rest = 0; + size_t rest = 0; if (dif_store_end < start + len) rest = start + len - dif_store_end; - paddr = kmap_atomic(sg_page(psgl)) + psgl->offset; + paddr = miter.addr; if (read) memcpy(paddr, start, len - rest); @@ -1821,8 +1825,8 @@ static void dif_copy_prot(struct scsi_cmnd *SCpnt, sector_t sector, sector += len / sizeof(*dif_storep); resid -= len; - kunmap_atomic(paddr); } + sg_miter_stop(&miter); } static int prot_verify_read(struct scsi_cmnd *SCpnt, sector_t start_sec, @@ -1929,55 +1933,62 @@ void dump_sector(unsigned char *buf, int len) static int prot_verify_write(struct scsi_cmnd *SCpnt, sector_t start_sec, unsigned int sectors, u32 ei_lba) { - int i, j, ret; + int ret; struct sd_dif_tuple *sdt; - struct scatterlist *dsgl; - struct scatterlist *psgl = scsi_prot_sglist(SCpnt); - void *daddr, *paddr; + void *daddr; sector_t sector = start_sec; int ppage_offset; + int dpage_offset; + struct sg_mapping_iter diter; + struct sg_mapping_iter piter; BUG_ON(scsi_sg_count(SCpnt) == 0); BUG_ON(scsi_prot_sg_count(SCpnt) == 0); - ppage_offset = 0; - - /* For each data page */ - scsi_for_each_sg(SCpnt, dsgl, scsi_sg_count(SCpnt), i) { - daddr = kmap_atomic(sg_page(dsgl)) + dsgl->offset; - paddr = kmap_atomic(sg_page(psgl)) + psgl->offset; - - /* For each sector-sized chunk in data page */ - for (j = 0; j < dsgl->length; j += scsi_debug_sector_size) { + sg_miter_start(&piter, scsi_prot_sglist(SCpnt), + scsi_prot_sg_count(SCpnt), + SG_MITER_ATOMIC | SG_MITER_FROM_SG); + sg_miter_start(&diter, scsi_sglist(SCpnt), scsi_sg_count(SCpnt), + SG_MITER_ATOMIC | SG_MITER_FROM_SG); + + /* For each protection page */ + while (sg_miter_next(&piter)) { + dpage_offset = 0; + if (WARN_ON(!sg_miter_next(&diter))) { + ret = 0x01; + goto out; + } + for (ppage_offset = 0; ppage_offset < piter.length; + ppage_offset += sizeof(struct sd_dif_tuple)) { /* If we're at the end of the current - * protection page advance to the next one + * data page advance to the next one */ - if (ppage_offset >= psgl->length) { - kunmap_atomic(paddr); - psgl = sg_next(psgl); - BUG_ON(psgl == NULL); - paddr = kmap_atomic(sg_page(psgl)) - + psgl->offset; - ppage_offset = 0; + if (dpage_offset >= diter.length) { + if (WARN_ON(!sg_miter_next(&diter))) { + ret = 0x01; + goto out; + } + dpage_offset = 0; } - sdt = paddr + ppage_offset; + sdt = piter.addr + ppage_offset; + daddr = diter.addr + dpage_offset; - ret = dif_verify(sdt, daddr + j, sector, ei_lba); + ret = dif_verify(sdt, daddr, sector, ei_lba); if (ret) { - dump_sector(daddr + j, scsi_debug_sector_size); + dump_sector(daddr, scsi_debug_sector_size); goto out; } sector++; ei_lba++; - ppage_offset += sizeof(struct sd_dif_tuple); + dpage_offset += scsi_debug_sector_size; } - - kunmap_atomic(paddr); - kunmap_atomic(daddr); + diter.consumed = dpage_offset; + sg_miter_stop(&diter); } + sg_miter_stop(&piter); dif_copy_prot(SCpnt, start_sec, sectors, false); dix_writes++; @@ -1986,8 +1997,8 @@ static int prot_verify_write(struct scsi_cmnd *SCpnt, sector_t start_sec, out: dif_errors++; - kunmap_atomic(paddr); - kunmap_atomic(daddr); + sg_miter_stop(&diter); + sg_miter_stop(&piter); return ret; } @@ -2311,11 +2322,11 @@ static int resp_report_luns(struct scsi_cmnd * scp, static int resp_xdwriteread(struct scsi_cmnd *scp, unsigned long long lba, unsigned int num, struct sdebug_dev_info *devip) { - int i, j, ret = -1; + int j; unsigned char *kaddr, *buf; unsigned int offset; - struct scatterlist *sg; struct scsi_data_buffer *sdb = scsi_in(scp); + struct sg_mapping_iter miter; /* better not to use temporary buffer. */ buf = kmalloc(scsi_bufflen(scp), GFP_ATOMIC); @@ -2328,22 +2339,20 @@ static int resp_xdwriteread(struct scsi_cmnd *scp, unsigned long long lba, scsi_sg_copy_to_buffer(scp, buf, scsi_bufflen(scp)); offset = 0; - for_each_sg(sdb->table.sgl, sg, sdb->table.nents, i) { - kaddr = (unsigned char *)kmap_atomic(sg_page(sg)); - if (!kaddr) - goto out; + sg_miter_start(&miter, sdb->table.sgl, sdb->table.nents, + SG_MITER_ATOMIC | SG_MITER_TO_SG); - for (j = 0; j < sg->length; j++) - *(kaddr + sg->offset + j) ^= *(buf + offset + j); + while (sg_miter_next(&miter)) { + kaddr = miter.addr; + for (j = 0; j < miter.length; j++) + *(kaddr + j) ^= *(buf + offset + j); - offset += sg->length; - kunmap_atomic(kaddr); + offset += miter.length; } - ret = 0; -out: + sg_miter_stop(&miter); kfree(buf); - return ret; + return 0; } /* When timer goes off this function is called. */