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("zone_size must be power-of-two\n");
  21                 return -EINVAL;
  22         }
  23         if (dev->zone_size > dev->size) {
  24                 pr_err("Zone size larger than device capacity\n");
  25                 return -EINVAL;
  26         }
  27
  28         dev->zone_size_sects = dev->zone_size << ZONE_SIZE_SHIFT;
  29         dev->nr_zones = dev_size >>
  30                                 (SECTOR_SHIFT + ilog2(dev->zone_size_sects));
  31         dev->zones = kvmalloc_array(dev->nr_zones, sizeof(struct blk_zone),
  32                         GFP_KERNEL | __GFP_ZERO);
  33         if (!dev->zones)
  34                 return -ENOMEM;
  35
  36         if (dev->zone_nr_conv >= dev->nr_zones) {
  37                 dev->zone_nr_conv = dev->nr_zones - 1;
  38                 pr_info("changed the number of conventional zones to %u",
  39                         dev->zone_nr_conv);
  40         }
  41
  42         for (i = 0; i <  dev->zone_nr_conv; i++) {
  43                 struct blk_zone *zone = &dev->zones[i];
  44
  45                 zone->start = sector;
  46                 zone->len = dev->zone_size_sects;
  47                 zone->wp = zone->start + zone->len;
  48                 zone->type = BLK_ZONE_TYPE_CONVENTIONAL;
  49                 zone->cond = BLK_ZONE_COND_NOT_WP;
  50
  51                 sector += dev->zone_size_sects;
  52         }
  53
  54         for (i = dev->zone_nr_conv; i < dev->nr_zones; i++) {
  55                 struct blk_zone *zone = &dev->zones[i];
  56
  57                 zone->start = zone->wp = sector;
  58                 zone->len = dev->zone_size_sects;
  59                 zone->type = BLK_ZONE_TYPE_SEQWRITE_REQ;
  60                 zone->cond = BLK_ZONE_COND_EMPTY;
  61
  62                 sector += dev->zone_size_sects;
  63         }
  64
  65         return 0;
  66 }
  67
  68 void null_zone_exit(struct nullb_device *dev)
  69 {
  70         kvfree(dev->zones);
  71 }
  72
  73 int null_zone_report(struct gendisk *disk, sector_t sector,
  74                      struct blk_zone *zones, unsigned int *nr_zones)
  75 {
  76         struct nullb *nullb = disk->private_data;
  77         struct nullb_device *dev = nullb->dev;
  78         unsigned int zno, nrz = 0;
  79
  80         zno = null_zone_no(dev, sector);
  81         if (zno < dev->nr_zones) {
  82                 nrz = min_t(unsigned int, *nr_zones, dev->nr_zones - zno);
  83                 memcpy(zones, &dev->zones[zno], nrz * sizeof(struct blk_zone));
  84         }
  85
  86         *nr_zones = nrz;
  87
  88         return 0;
  89 }
  90
  91 static blk_status_t null_zone_write(struct nullb_cmd *cmd, sector_t sector,
  92                      unsigned int nr_sectors)
  93 {
  94         struct nullb_device *dev = cmd->nq->dev;
  95         unsigned int zno = null_zone_no(dev, sector);
  96         struct blk_zone *zone = &dev->zones[zno];
  97
  98         switch (zone->cond) {
  99         case BLK_ZONE_COND_FULL:
 100                 /* Cannot write to a full zone */
 101                 cmd->error = BLK_STS_IOERR;
 102                 return BLK_STS_IOERR;
 103         case BLK_ZONE_COND_EMPTY:
 104         case BLK_ZONE_COND_IMP_OPEN:
 105                 /* Writes must be at the write pointer position */
 106                 if (sector != zone->wp)
 107                         return BLK_STS_IOERR;
 108
 109                 if (zone->cond == BLK_ZONE_COND_EMPTY)
 110                         zone->cond = BLK_ZONE_COND_IMP_OPEN;
 111
 112                 zone->wp += nr_sectors;
 113                 if (zone->wp == zone->start + zone->len)
 114                         zone->cond = BLK_ZONE_COND_FULL;
 115                 break;
 116         case BLK_ZONE_COND_NOT_WP:
 117                 break;
 118         default:
 119                 /* Invalid zone condition */
 120                 return BLK_STS_IOERR;
 121         }
 122         return BLK_STS_OK;
 123 }
 124
 125 static blk_status_t null_zone_reset(struct nullb_cmd *cmd, sector_t sector)
 126 {
 127         struct nullb_device *dev = cmd->nq->dev;
 128         unsigned int zno = null_zone_no(dev, sector);
 129         struct blk_zone *zone = &dev->zones[zno];
 130         size_t i;
 131
 132         switch (req_op(cmd->rq)) {
 133         case REQ_OP_ZONE_RESET_ALL:
 134                 for (i = 0; i < dev->nr_zones; i++) {
 135                         if (zone[i].type == BLK_ZONE_TYPE_CONVENTIONAL)
 136                                 continue;
 137                         zone[i].cond = BLK_ZONE_COND_EMPTY;
 138                         zone[i].wp = zone[i].start;
 139                 }
 140                 break;
 141         case REQ_OP_ZONE_RESET:
 142                 if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
 143                         return BLK_STS_IOERR;
 144
 145                 zone->cond = BLK_ZONE_COND_EMPTY;
 146                 zone->wp = zone->start;
 147                 break;
 148         default:
 149                 return BLK_STS_NOTSUPP;
 150         }
 151         return BLK_STS_OK;
 152 }
 153
 154 blk_status_t null_handle_zoned(struct nullb_cmd *cmd, enum req_opf op,
 155                                sector_t sector, sector_t nr_sectors)
 156 {
 157         switch (op) {
 158         case REQ_OP_WRITE:
 159                 return null_zone_write(cmd, sector, nr_sectors);
 160         case REQ_OP_ZONE_RESET:
 161         case REQ_OP_ZONE_RESET_ALL:
 162                 return null_zone_reset(cmd, sector);
 163         default:
 164                 return BLK_STS_OK;
 165         }
 166 }