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path: root/drivers/block/null_blk_zoned.c
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Diffstat (limited to 'drivers/block/null_blk_zoned.c')
-rw-r--r--drivers/block/null_blk_zoned.c149
1 files changed, 149 insertions, 0 deletions
diff --git a/drivers/block/null_blk_zoned.c b/drivers/block/null_blk_zoned.c
new file mode 100644
index 000000000000..a979ca00d7be
--- /dev/null
+++ b/drivers/block/null_blk_zoned.c
@@ -0,0 +1,149 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/vmalloc.h>
+#include "null_blk.h"
+
+/* zone_size in MBs to sectors. */
+#define ZONE_SIZE_SHIFT 11
+
+static inline unsigned int null_zone_no(struct nullb_device *dev, sector_t sect)
+{
+ return sect >> ilog2(dev->zone_size_sects);
+}
+
+int null_zone_init(struct nullb_device *dev)
+{
+ sector_t dev_size = (sector_t)dev->size * 1024 * 1024;
+ sector_t sector = 0;
+ unsigned int i;
+
+ if (!is_power_of_2(dev->zone_size)) {
+ pr_err("null_blk: zone_size must be power-of-two\n");
+ return -EINVAL;
+ }
+
+ dev->zone_size_sects = dev->zone_size << ZONE_SIZE_SHIFT;
+ dev->nr_zones = dev_size >>
+ (SECTOR_SHIFT + ilog2(dev->zone_size_sects));
+ dev->zones = kvmalloc_array(dev->nr_zones, sizeof(struct blk_zone),
+ GFP_KERNEL | __GFP_ZERO);
+ if (!dev->zones)
+ return -ENOMEM;
+
+ for (i = 0; i < dev->nr_zones; i++) {
+ struct blk_zone *zone = &dev->zones[i];
+
+ zone->start = zone->wp = sector;
+ zone->len = dev->zone_size_sects;
+ zone->type = BLK_ZONE_TYPE_SEQWRITE_REQ;
+ zone->cond = BLK_ZONE_COND_EMPTY;
+
+ sector += dev->zone_size_sects;
+ }
+
+ return 0;
+}
+
+void null_zone_exit(struct nullb_device *dev)
+{
+ kvfree(dev->zones);
+}
+
+static void null_zone_fill_rq(struct nullb_device *dev, struct request *rq,
+ unsigned int zno, unsigned int nr_zones)
+{
+ struct blk_zone_report_hdr *hdr = NULL;
+ struct bio_vec bvec;
+ struct bvec_iter iter;
+ void *addr;
+ unsigned int zones_to_cpy;
+
+ bio_for_each_segment(bvec, rq->bio, iter) {
+ addr = kmap_atomic(bvec.bv_page);
+
+ zones_to_cpy = bvec.bv_len / sizeof(struct blk_zone);
+
+ if (!hdr) {
+ hdr = (struct blk_zone_report_hdr *)addr;
+ hdr->nr_zones = nr_zones;
+ zones_to_cpy--;
+ addr += sizeof(struct blk_zone_report_hdr);
+ }
+
+ zones_to_cpy = min_t(unsigned int, zones_to_cpy, nr_zones);
+
+ memcpy(addr, &dev->zones[zno],
+ zones_to_cpy * sizeof(struct blk_zone));
+
+ kunmap_atomic(addr);
+
+ nr_zones -= zones_to_cpy;
+ zno += zones_to_cpy;
+
+ if (!nr_zones)
+ break;
+ }
+}
+
+blk_status_t null_zone_report(struct nullb *nullb,
+ struct nullb_cmd *cmd)
+{
+ struct nullb_device *dev = nullb->dev;
+ struct request *rq = cmd->rq;
+ unsigned int zno = null_zone_no(dev, blk_rq_pos(rq));
+ unsigned int nr_zones = dev->nr_zones - zno;
+ unsigned int max_zones = (blk_rq_bytes(rq) /
+ sizeof(struct blk_zone)) - 1;
+
+ nr_zones = min_t(unsigned int, nr_zones, max_zones);
+
+ null_zone_fill_rq(nullb->dev, rq, zno, nr_zones);
+
+ return BLK_STS_OK;
+}
+
+void null_zone_write(struct nullb_cmd *cmd)
+{
+ struct nullb_device *dev = cmd->nq->dev;
+ struct request *rq = cmd->rq;
+ sector_t sector = blk_rq_pos(rq);
+ unsigned int rq_sectors = blk_rq_sectors(rq);
+ unsigned int zno = null_zone_no(dev, sector);
+ struct blk_zone *zone = &dev->zones[zno];
+
+ switch (zone->cond) {
+ case BLK_ZONE_COND_FULL:
+ /* Cannot write to a full zone */
+ cmd->error = BLK_STS_IOERR;
+ break;
+ case BLK_ZONE_COND_EMPTY:
+ case BLK_ZONE_COND_IMP_OPEN:
+ /* Writes must be at the write pointer position */
+ if (blk_rq_pos(rq) != zone->wp) {
+ cmd->error = BLK_STS_IOERR;
+ break;
+ }
+
+ if (zone->cond == BLK_ZONE_COND_EMPTY)
+ zone->cond = BLK_ZONE_COND_IMP_OPEN;
+
+ zone->wp += rq_sectors;
+ if (zone->wp == zone->start + zone->len)
+ zone->cond = BLK_ZONE_COND_FULL;
+ break;
+ default:
+ /* Invalid zone condition */
+ cmd->error = BLK_STS_IOERR;
+ break;
+ }
+}
+
+void null_zone_reset(struct nullb_cmd *cmd)
+{
+ struct nullb_device *dev = cmd->nq->dev;
+ struct request *rq = cmd->rq;
+ unsigned int zno = null_zone_no(dev, blk_rq_pos(rq));
+ struct blk_zone *zone = &dev->zones[zno];
+
+ zone->cond = BLK_ZONE_COND_EMPTY;
+ zone->wp = zone->start;
+}