tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2#include <linux/vmalloc.h>
3#include "null_blk.h"
4
5/* zone_size in MBs to sectors. */
6#define ZONE_SIZE_SHIFT 11
7
8static inline unsigned int null_zone_no(struct nullb_device *dev, sector_t sect)
9{
10 return sect >> ilog2(dev->zone_size_sects);
11}
12
13int null_zone_init(struct nullb_device *dev)
14{
15 sector_t dev_size = (sector_t)dev->size * 1024 * 1024;
16 sector_t sector = 0;
17 unsigned int i;
18
19 if (!is_power_of_2(dev->zone_size)) {
20 pr_err("null_blk: zone_size must be power-of-two\n");
21 return -EINVAL;
22 }
23
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);
29 if (!dev->zones)
30 return -ENOMEM;
31
32 for (i = 0; i < dev->nr_zones; i++) {
33 struct blk_zone *zone = &dev->zones[i];
34
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;
39
40 sector += dev->zone_size_sects;
41 }
42
43 return 0;
44}
45
46void null_zone_exit(struct nullb_device *dev)
47{
48 kvfree(dev->zones);
49}
50
51int null_zone_report(struct gendisk *disk, sector_t sector,
52 struct blk_zone *zones, unsigned int *nr_zones,
53 gfp_t gfp_mask)
54{
55 struct nullb *nullb = disk->private_data;
56 struct nullb_device *dev = nullb->dev;
57 unsigned int zno, nrz = 0;
58
59 if (!dev->zoned)
60 /* Not a zoned null device */
61 return -EOPNOTSUPP;
62
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));
67 }
68
69 *nr_zones = nrz;
70
71 return 0;
72}
73
74void null_zone_write(struct nullb_cmd *cmd, sector_t sector,
75 unsigned int nr_sectors)
76{
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];
80
81 switch (zone->cond) {
82 case BLK_ZONE_COND_FULL:
83 /* Cannot write to a full zone */
84 cmd->error = BLK_STS_IOERR;
85 break;
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;
91 break;
92 }
93
94 if (zone->cond == BLK_ZONE_COND_EMPTY)
95 zone->cond = BLK_ZONE_COND_IMP_OPEN;
96
97 zone->wp += nr_sectors;
98 if (zone->wp == zone->start + zone->len)
99 zone->cond = BLK_ZONE_COND_FULL;
100 break;
101 default:
102 /* Invalid zone condition */
103 cmd->error = BLK_STS_IOERR;
104 break;
105 }
106}
107
108void null_zone_reset(struct nullb_cmd *cmd, sector_t sector)
109{
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];
113
114 zone->cond = BLK_ZONE_COND_EMPTY;
115 zone->wp = zone->start;
116}