1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/vmalloc.h>
5 /* zone_size in MBs to sectors. */
6 #define ZONE_SIZE_SHIFT 11
8 static inline unsigned int null_zone_no(struct nullb_device *dev, sector_t sect)
10 return sect >> ilog2(dev->zone_size_sects);
13 int null_zone_init(struct nullb_device *dev)
15 sector_t dev_size = (sector_t)dev->size * 1024 * 1024;
19 if (!is_power_of_2(dev->zone_size)) {
20 pr_err("null_blk: zone_size must be power-of-two\n");
24 dev->zone_size_sects = dev->zone_size << ZONE_SIZE_SHIFT;
25 dev->nr_zones = dev_size >>
26 (SECTOR_SHIFT + ilog2(dev->zone_size_sects));
27 dev->zones = kvmalloc_array(dev->nr_zones, sizeof(struct blk_zone),
28 GFP_KERNEL | __GFP_ZERO);
32 for (i = 0; i < dev->nr_zones; i++) {
33 struct blk_zone *zone = &dev->zones[i];
35 zone->start = zone->wp = sector;
36 zone->len = dev->zone_size_sects;
37 zone->type = BLK_ZONE_TYPE_SEQWRITE_REQ;
38 zone->cond = BLK_ZONE_COND_EMPTY;
40 sector += dev->zone_size_sects;
46 void null_zone_exit(struct nullb_device *dev)
51 int null_zone_report(struct gendisk *disk, sector_t sector,
52 struct blk_zone *zones, unsigned int *nr_zones,
55 struct nullb *nullb = disk->private_data;
56 struct nullb_device *dev = nullb->dev;
57 unsigned int zno, nrz = 0;
60 /* Not a zoned null device */
63 zno = null_zone_no(dev, sector);
64 if (zno < dev->nr_zones) {
65 nrz = min_t(unsigned int, *nr_zones, dev->nr_zones - zno);
66 memcpy(zones, &dev->zones[zno], nrz * sizeof(struct blk_zone));
74 void null_zone_write(struct nullb_cmd *cmd, sector_t sector,
75 unsigned int nr_sectors)
77 struct nullb_device *dev = cmd->nq->dev;
78 unsigned int zno = null_zone_no(dev, sector);
79 struct blk_zone *zone = &dev->zones[zno];
82 case BLK_ZONE_COND_FULL:
83 /* Cannot write to a full zone */
84 cmd->error = BLK_STS_IOERR;
86 case BLK_ZONE_COND_EMPTY:
87 case BLK_ZONE_COND_IMP_OPEN:
88 /* Writes must be at the write pointer position */
89 if (sector != zone->wp) {
90 cmd->error = BLK_STS_IOERR;
94 if (zone->cond == BLK_ZONE_COND_EMPTY)
95 zone->cond = BLK_ZONE_COND_IMP_OPEN;
97 zone->wp += nr_sectors;
98 if (zone->wp == zone->start + zone->len)
99 zone->cond = BLK_ZONE_COND_FULL;
102 /* Invalid zone condition */
103 cmd->error = BLK_STS_IOERR;
108 void null_zone_reset(struct nullb_cmd *cmd, sector_t sector)
110 struct nullb_device *dev = cmd->nq->dev;
111 unsigned int zno = null_zone_no(dev, sector);
112 struct blk_zone *zone = &dev->zones[zno];
114 zone->cond = BLK_ZONE_COND_EMPTY;
115 zone->wp = zone->start;