*/
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) {
}
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
*/
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);
+ }
}
/*
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",
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;
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)
{
projects / platform / kernel / linux-starfive.git / commitdiff