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         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
  46 void null_zone_exit(struct nullb_device *dev)
  47 {
  48         kvfree(dev->zones);
  49 }
  50
  51 int 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
  74 void 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
 108 void 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 }