diff options
| -rw-r--r-- | arch/s390/include/uapi/asm/dasd.h | 6 | ||||
| -rw-r--r-- | drivers/s390/block/dasd.c | 19 | ||||
| -rw-r--r-- | drivers/s390/block/dasd_devmap.c | 1 | ||||
| -rw-r--r-- | drivers/s390/block/dasd_fba.c | 202 | ||||
| -rw-r--r-- | drivers/s390/block/dasd_int.h | 3 |
5 files changed, 226 insertions, 5 deletions
diff --git a/arch/s390/include/uapi/asm/dasd.h b/arch/s390/include/uapi/asm/dasd.h index 1340311dab77..ab5797cdc1b7 100644 --- a/arch/s390/include/uapi/asm/dasd.h +++ b/arch/s390/include/uapi/asm/dasd.h @@ -72,7 +72,10 @@ typedef struct dasd_information2_t { * 0x02: use diag discipline (diag) * 0x04: set the device initially online (internal use only) * 0x08: enable ERP related logging - * 0x20: give access to raw eckd data + * 0x10: allow I/O to fail on lost paths + * 0x20: allow I/O to fail when a lock was stolen + * 0x40: give access to raw eckd data + * 0x80: enable discard support */ #define DASD_FEATURE_DEFAULT 0x00 #define DASD_FEATURE_READONLY 0x01 @@ -82,6 +85,7 @@ typedef struct dasd_information2_t { #define DASD_FEATURE_FAILFAST 0x10 #define DASD_FEATURE_FAILONSLCK 0x20 #define DASD_FEATURE_USERAW 0x40 +#define DASD_FEATURE_DISCARD 0x80 #define DASD_PARTN_BITS 2 diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c index 83f80710d555..9c97ad1ee121 100644 --- a/drivers/s390/block/dasd.c +++ b/drivers/s390/block/dasd.c @@ -3178,7 +3178,9 @@ static int dasd_alloc_queue(struct dasd_block *block) */ static void dasd_setup_queue(struct dasd_block *block) { + unsigned int logical_block_size = block->bp_block; struct request_queue *q = block->request_queue; + unsigned int max_bytes, max_discard_sectors; int max; if (block->base->features & DASD_FEATURE_USERAW) { @@ -3195,7 +3197,7 @@ static void dasd_setup_queue(struct dasd_block *block) } queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q); q->limits.max_dev_sectors = max; - blk_queue_logical_block_size(q, block->bp_block); + blk_queue_logical_block_size(q, logical_block_size); blk_queue_max_hw_sectors(q, max); blk_queue_max_segments(q, USHRT_MAX); /* with page sized segments we can translate each segement into @@ -3203,6 +3205,21 @@ static void dasd_setup_queue(struct dasd_block *block) */ blk_queue_max_segment_size(q, PAGE_SIZE); blk_queue_segment_boundary(q, PAGE_SIZE - 1); + + /* Only activate blocklayer discard support for devices that support it */ + if (block->base->features & DASD_FEATURE_DISCARD) { + q->limits.discard_granularity = logical_block_size; + q->limits.discard_alignment = PAGE_SIZE; + + /* Calculate max_discard_sectors and make it PAGE aligned */ + max_bytes = USHRT_MAX * logical_block_size; + max_bytes = ALIGN(max_bytes, PAGE_SIZE) - PAGE_SIZE; + max_discard_sectors = max_bytes / logical_block_size; + + blk_queue_max_discard_sectors(q, max_discard_sectors); + blk_queue_max_write_zeroes_sectors(q, max_discard_sectors); + queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q); + } } /* diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c index 7b539d92eeaf..e38042ce94e6 100644 --- a/drivers/s390/block/dasd_devmap.c +++ b/drivers/s390/block/dasd_devmap.c @@ -1676,6 +1676,7 @@ dasd_set_feature(struct ccw_device *cdev, int feature, int flag) spin_unlock(&dasd_devmap_lock); return 0; } +EXPORT_SYMBOL(dasd_set_feature); int diff --git a/drivers/s390/block/dasd_fba.c b/drivers/s390/block/dasd_fba.c index 462cab5d4302..6168ccdb389c 100644 --- a/drivers/s390/block/dasd_fba.c +++ b/drivers/s390/block/dasd_fba.c @@ -174,6 +174,9 @@ dasd_fba_check_characteristics(struct dasd_device *device) if (readonly) set_bit(DASD_FLAG_DEVICE_RO, &device->flags); + /* FBA supports discard, set the according feature bit */ + dasd_set_feature(cdev, DASD_FEATURE_DISCARD, 1); + dev_info(&device->cdev->dev, "New FBA DASD %04X/%02X (CU %04X/%02X) with %d MB " "and %d B/blk%s\n", @@ -247,9 +250,192 @@ static void dasd_fba_check_for_device_change(struct dasd_device *device, dasd_generic_handle_state_change(device); }; -static struct dasd_ccw_req *dasd_fba_build_cp(struct dasd_device * memdev, - struct dasd_block *block, - struct request *req) + +/* + * Builds a CCW with no data payload + */ +static void ccw_write_no_data(struct ccw1 *ccw) +{ + ccw->cmd_code = DASD_FBA_CCW_WRITE; + ccw->flags |= CCW_FLAG_SLI; + ccw->count = 0; +} + +/* + * Builds a CCW that writes only zeroes. + */ +static void ccw_write_zero(struct ccw1 *ccw, int count) +{ + ccw->cmd_code = DASD_FBA_CCW_WRITE; + ccw->flags |= CCW_FLAG_SLI; + ccw->count = count; + ccw->cda = (__u32) (addr_t) page_to_phys(ZERO_PAGE(0)); +} + +/* + * Helper function to count the amount of necessary CCWs within a given range + * with 4k alignment and command chaining in mind. + */ +static int count_ccws(sector_t first_rec, sector_t last_rec, + unsigned int blocks_per_page) +{ + sector_t wz_stop = 0, d_stop = 0; + int cur_pos = 0; + int count = 0; + + if (first_rec % blocks_per_page != 0) { + wz_stop = first_rec + blocks_per_page - + (first_rec % blocks_per_page) - 1; + if (wz_stop > last_rec) + wz_stop = last_rec; + cur_pos = wz_stop - first_rec + 1; + count++; + } + + if (last_rec - (first_rec + cur_pos) + 1 >= blocks_per_page) { + if ((last_rec - blocks_per_page + 1) % blocks_per_page != 0) + d_stop = last_rec - ((last_rec - blocks_per_page + 1) % + blocks_per_page); + else + d_stop = last_rec; + + cur_pos += d_stop - (first_rec + cur_pos) + 1; + count++; + } + + if (cur_pos == 0 || first_rec + cur_pos - 1 < last_rec) + count++; + + return count; +} + +/* + * This function builds a CCW request for block layer discard requests. + * Each page in the z/VM hypervisor that represents certain records of an FBA + * device will be padded with zeros. This is a special behaviour of the WRITE + * command which is triggered when no data payload is added to the CCW. + * + * Note: Due to issues in some z/VM versions, we can't fully utilise this + * special behaviour. We have to keep a 4k (or 8 block) alignment in mind to + * work around those issues and write actual zeroes to the unaligned parts in + * the request. This workaround might be removed in the future. + */ +static struct dasd_ccw_req *dasd_fba_build_cp_discard( + struct dasd_device *memdev, + struct dasd_block *block, + struct request *req) +{ + struct LO_fba_data *LO_data; + struct dasd_ccw_req *cqr; + struct ccw1 *ccw; + + sector_t wz_stop = 0, d_stop = 0; + sector_t first_rec, last_rec; + + unsigned int blksize = block->bp_block; + unsigned int blocks_per_page; + int wz_count = 0; + int d_count = 0; + int cur_pos = 0; /* Current position within the extent */ + int count = 0; + int cplength; + int datasize; + int nr_ccws; + + first_rec = blk_rq_pos(req) >> block->s2b_shift; + last_rec = + (blk_rq_pos(req) + blk_rq_sectors(req) - 1) >> block->s2b_shift; + count = last_rec - first_rec + 1; + + blocks_per_page = BLOCKS_PER_PAGE(blksize); + nr_ccws = count_ccws(first_rec, last_rec, blocks_per_page); + + /* define extent + nr_ccws * locate record + nr_ccws * single CCW */ + cplength = 1 + 2 * nr_ccws; + datasize = sizeof(struct DE_fba_data) + + nr_ccws * (sizeof(struct LO_fba_data) + sizeof(struct ccw1)); + + cqr = dasd_smalloc_request(DASD_FBA_MAGIC, cplength, datasize, memdev); + if (IS_ERR(cqr)) + return cqr; + + ccw = cqr->cpaddr; + + define_extent(ccw++, cqr->data, WRITE, blksize, first_rec, count); + LO_data = cqr->data + sizeof(struct DE_fba_data); + + /* First part is not aligned. Calculate range to write zeroes. */ + if (first_rec % blocks_per_page != 0) { + wz_stop = first_rec + blocks_per_page - + (first_rec % blocks_per_page) - 1; + if (wz_stop > last_rec) + wz_stop = last_rec; + wz_count = wz_stop - first_rec + 1; + + ccw[-1].flags |= CCW_FLAG_CC; + locate_record(ccw++, LO_data++, WRITE, cur_pos, wz_count); + + ccw[-1].flags |= CCW_FLAG_CC; + ccw_write_zero(ccw++, wz_count * blksize); + + cur_pos = wz_count; + } + + /* We can do proper discard when we've got at least blocks_per_page blocks. */ + if (last_rec - (first_rec + cur_pos) + 1 >= blocks_per_page) { + /* is last record at page boundary? */ + if ((last_rec - blocks_per_page + 1) % blocks_per_page != 0) + d_stop = last_rec - ((last_rec - blocks_per_page + 1) % + blocks_per_page); + else + d_stop = last_rec; + + d_count = d_stop - (first_rec + cur_pos) + 1; + + ccw[-1].flags |= CCW_FLAG_CC; + locate_record(ccw++, LO_data++, WRITE, cur_pos, d_count); + + ccw[-1].flags |= CCW_FLAG_CC; + ccw_write_no_data(ccw++); + + cur_pos += d_count; + } + + /* We might still have some bits left which need to be zeroed. */ + if (cur_pos == 0 || first_rec + cur_pos - 1 < last_rec) { + if (d_stop != 0) + wz_count = last_rec - d_stop; + else if (wz_stop != 0) + wz_count = last_rec - wz_stop; + else + wz_count = count; + + ccw[-1].flags |= CCW_FLAG_CC; + locate_record(ccw++, LO_data++, WRITE, cur_pos, wz_count); + + ccw[-1].flags |= CCW_FLAG_CC; + ccw_write_zero(ccw++, wz_count * blksize); + } + + if (blk_noretry_request(req) || + block->base->features & DASD_FEATURE_FAILFAST) + set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags); + + cqr->startdev = memdev; + cqr->memdev = memdev; + cqr->block = block; + cqr->expires = memdev->default_expires * HZ; /* default 5 minutes */ + cqr->retries = memdev->default_retries; + cqr->buildclk = get_tod_clock(); + cqr->status = DASD_CQR_FILLED; + + return cqr; +} + +static struct dasd_ccw_req *dasd_fba_build_cp_regular( + struct dasd_device *memdev, + struct dasd_block *block, + struct request *req) { struct dasd_fba_private *private = block->base->private; unsigned long *idaws; @@ -372,6 +558,16 @@ static struct dasd_ccw_req *dasd_fba_build_cp(struct dasd_device * memdev, return cqr; } +static struct dasd_ccw_req *dasd_fba_build_cp(struct dasd_device *memdev, + struct dasd_block *block, + struct request *req) +{ + if (req_op(req) == REQ_OP_DISCARD || req_op(req) == REQ_OP_WRITE_ZEROES) + return dasd_fba_build_cp_discard(memdev, block, req); + else + return dasd_fba_build_cp_regular(memdev, block, req); +} + static int dasd_fba_free_cp(struct dasd_ccw_req *cqr, struct request *req) { diff --git a/drivers/s390/block/dasd_int.h b/drivers/s390/block/dasd_int.h index 66248795b973..f9e25fc03d6b 100644 --- a/drivers/s390/block/dasd_int.h +++ b/drivers/s390/block/dasd_int.h @@ -167,6 +167,9 @@ do { \ printk(d_loglevel PRINTK_HEADER " " d_string "\n", d_args); \ } while(0) +/* Macro to calculate number of blocks per page */ +#define BLOCKS_PER_PAGE(blksize) (PAGE_SIZE / blksize) + struct dasd_ccw_req { unsigned int magic; /* Eye catcher */ struct list_head devlist; /* for dasd_device request queue */ |