drivers/block/null_blk_zoned.c

   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
   8 static inline unsigned int null_zone_no(struct nullb_device *dev, sector_t sect)
   9 {
  10         return sect >> ilog2(dev->zone_size_sects);
  11 }
  12
  13 int 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         if (dev->zone_nr_conv >= dev->nr_zones) {
  33                 dev->zone_nr_conv = dev->nr_zones - 1;
  34                 pr_info("null_blk: changed the number of conventional zones to %u",
  35                         dev->zone_nr_conv);
  36         }
  37
  38         for (i = 0; i <  dev->zone_nr_conv; i++) {
  39                 struct blk_zone *zone = &dev->zones[i];
  40
  41                 zone->start = sector;
  42                 zone->len = dev->zone_size_sects;
  43                 zone->wp = zone->start + zone->len;
  44                 zone->type = BLK_ZONE_TYPE_CONVENTIONAL;
  45                 zone->cond = BLK_ZONE_COND_NOT_WP;
  46
  47                 sector += dev->zone_size_sects;
  48         }
  49
  50         for (i = dev->zone_nr_conv; i < dev->nr_zones; i++) {
  51                 struct blk_zone *zone = &dev->zones[i];
  52
  53                 zone->start = zone->wp = sector;
  54                 zone->len = dev->zone_size_sects;
  55                 zone->type = BLK_ZONE_TYPE_SEQWRITE_REQ;
  56                 zone->cond = BLK_ZONE_COND_EMPTY;
  57
  58                 sector += dev->zone_size_sects;
  59         }
  60
  61         return 0;
  62 }
  63
  64 void null_zone_exit(struct nullb_device *dev)
  65 {
  66         kvfree(dev->zones);
  67 }
  68
  69 int null_zone_report(struct gendisk *disk, sector_t sector,
  70                      struct blk_zone *zones, unsigned int *nr_zones,
  71                      gfp_t gfp_mask)
  72 {
  73         struct nullb *nullb = disk->private_data;
  74         struct nullb_device *dev = nullb->dev;
  75         unsigned int zno, nrz = 0;
  76
  77         if (!dev->zoned)
  78                 /* Not a zoned null device */
  79                 return -EOPNOTSUPP;
  80
  81         zno = null_zone_no(dev, sector);
  82         if (zno < dev->nr_zones) {
  83                 nrz = min_t(unsigned int, *nr_zones, dev->nr_zones - zno);
  84                 memcpy(zones, &dev->zones[zno], nrz * sizeof(struct blk_zone));
  85         }
  86
  87         *nr_zones = nrz;
  88
  89         return 0;
  90 }
  91
  92 void null_zone_write(struct nullb_cmd *cmd, sector_t sector,
  93                      unsigned int nr_sectors)
  94 {
  95         struct nullb_device *dev = cmd->nq->dev;
  96         unsigned int zno = null_zone_no(dev, sector);
  97         struct blk_zone *zone = &dev->zones[zno];
  98
  99         switch (zone->cond) {
 100         case BLK_ZONE_COND_FULL:
 101                 /* Cannot write to a full zone */
 102                 cmd->error = BLK_STS_IOERR;
 103                 break;
 104         case BLK_ZONE_COND_EMPTY:
 105         case BLK_ZONE_COND_IMP_OPEN:
 106                 /* Writes must be at the write pointer position */
 107                 if (sector != zone->wp) {
 108                         cmd->error = BLK_STS_IOERR;
 109                         break;
 110                 }
 111
 112                 if (zone->cond == BLK_ZONE_COND_EMPTY)
 113                         zone->cond = BLK_ZONE_COND_IMP_OPEN;
 114
 115                 zone->wp += nr_sectors;
 116                 if (zone->wp == zone->start + zone->len)
 117                         zone->cond = BLK_ZONE_COND_FULL;
 118                 break;
 119         case BLK_ZONE_COND_NOT_WP:
 120                 break;
 121         default:
 122                 /* Invalid zone condition */
 123                 cmd->error = BLK_STS_IOERR;
 124                 break;
 125         }
 126 }
 127
 128 void null_zone_reset(struct nullb_cmd *cmd, sector_t sector)
 129 {
 130         struct nullb_device *dev = cmd->nq->dev;
 131         unsigned int zno = null_zone_no(dev, sector);
 132         struct blk_zone *zone = &dev->zones[zno];
 133
 134         if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL) {
 135                 cmd->error = BLK_STS_IOERR;
 136                 return;
 137         }
 138
 139         zone->cond = BLK_ZONE_COND_EMPTY;
 140         zone->wp = zone->start;
 141 }