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// SPDX-License-Identifier: GPL-2.0
#include <linux/vmalloc.h>
#include "null_blk.h"
/* zone_size in MBs to sectors. */
#define ZONE_SIZE_SHIFT 11
static inline unsigned int null_zone_no(struct nullb_device *dev, sector_t sect)
{
return sect >> ilog2(dev->zone_size_sects);
}
int null_zone_init(struct nullb_device *dev)
{
sector_t dev_size = (sector_t)dev->size * 1024 * 1024;
sector_t sector = 0;
unsigned int i;
if (!is_power_of_2(dev->zone_size)) {
pr_err("zone_size must be power-of-two\n");
return -EINVAL;
}
dev->zone_size_sects = dev->zone_size << ZONE_SIZE_SHIFT;
dev->nr_zones = dev_size >>
(SECTOR_SHIFT + ilog2(dev->zone_size_sects));
dev->zones = kvmalloc_array(dev->nr_zones, sizeof(struct blk_zone),
GFP_KERNEL | __GFP_ZERO);
if (!dev->zones)
return -ENOMEM;
if (dev->zone_nr_conv >= dev->nr_zones) {
dev->zone_nr_conv = dev->nr_zones - 1;
pr_info("changed the number of conventional zones to %u",
dev->zone_nr_conv);
}
for (i = 0; i < dev->zone_nr_conv; i++) {
struct blk_zone *zone = &dev->zones[i];
zone->start = sector;
zone->len = dev->zone_size_sects;
zone->wp = zone->start + zone->len;
zone->type = BLK_ZONE_TYPE_CONVENTIONAL;
zone->cond = BLK_ZONE_COND_NOT_WP;
sector += dev->zone_size_sects;
}
for (i = dev->zone_nr_conv; i < dev->nr_zones; i++) {
struct blk_zone *zone = &dev->zones[i];
zone->start = zone->wp = sector;
zone->len = dev->zone_size_sects;
zone->type = BLK_ZONE_TYPE_SEQWRITE_REQ;
zone->cond = BLK_ZONE_COND_EMPTY;
sector += dev->zone_size_sects;
}
return 0;
}
void null_zone_exit(struct nullb_device *dev)
{
kvfree(dev->zones);
}
int null_zone_report(struct gendisk *disk, sector_t sector,
struct blk_zone *zones, unsigned int *nr_zones)
{
struct nullb *nullb = disk->private_data;
struct nullb_device *dev = nullb->dev;
unsigned int zno, nrz = 0;
zno = null_zone_no(dev, sector);
if (zno < dev->nr_zones) {
nrz = min_t(unsigned int, *nr_zones, dev->nr_zones - zno);
memcpy(zones, &dev->zones[zno], nrz * sizeof(struct blk_zone));
}
*nr_zones = nrz;
return 0;
}
size_t null_zone_valid_read_len(struct nullb *nullb,
sector_t sector, unsigned int len)
{
struct nullb_device *dev = nullb->dev;
struct blk_zone *zone = &dev->zones[null_zone_no(dev, sector)];
unsigned int nr_sectors = len >> SECTOR_SHIFT;
/* Read must be below the write pointer position */
if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL ||
sector + nr_sectors <= zone->wp)
return len;
if (sector > zone->wp)
return 0;
return (zone->wp - sector) << SECTOR_SHIFT;
}
static blk_status_t null_zone_write(struct nullb_cmd *cmd, sector_t sector,
unsigned int nr_sectors)
{
struct nullb_device *dev = cmd->nq->dev;
unsigned int zno = null_zone_no(dev, sector);
struct blk_zone *zone = &dev->zones[zno];
switch (zone->cond) {
case BLK_ZONE_COND_FULL:
/* Cannot write to a full zone */
cmd->error = BLK_STS_IOERR;
return BLK_STS_IOERR;
case BLK_ZONE_COND_EMPTY:
case BLK_ZONE_COND_IMP_OPEN:
/* Writes must be at the write pointer position */
if (sector != zone->wp)
return BLK_STS_IOERR;
if (zone->cond == BLK_ZONE_COND_EMPTY)
zone->cond = BLK_ZONE_COND_IMP_OPEN;
zone->wp += nr_sectors;
if (zone->wp == zone->start + zone->len)
zone->cond = BLK_ZONE_COND_FULL;
break;
case BLK_ZONE_COND_NOT_WP:
break;
default:
/* Invalid zone condition */
return BLK_STS_IOERR;
}
return BLK_STS_OK;
}
static blk_status_t null_zone_reset(struct nullb_cmd *cmd, sector_t sector)
{
struct nullb_device *dev = cmd->nq->dev;
struct blk_zone *zone = &dev->zones[null_zone_no(dev, sector)];
size_t i;
switch (req_op(cmd->rq)) {
case REQ_OP_ZONE_RESET_ALL:
for (i = 0; i < dev->nr_zones; i++) {
if (zone[i].type == BLK_ZONE_TYPE_CONVENTIONAL)
continue;
zone[i].cond = BLK_ZONE_COND_EMPTY;
zone[i].wp = zone[i].start;
}
break;
case REQ_OP_ZONE_RESET:
if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
return BLK_STS_IOERR;
zone->cond = BLK_ZONE_COND_EMPTY;
zone->wp = zone->start;
break;
default:
cmd->error = BLK_STS_NOTSUPP;
break;
}
return BLK_STS_OK;
}
blk_status_t null_handle_zoned(struct nullb_cmd *cmd, enum req_opf op,
sector_t sector, sector_t nr_sectors)
{
switch (op) {
case REQ_OP_WRITE:
return null_zone_write(cmd, sector, nr_sectors);
case REQ_OP_ZONE_RESET:
case REQ_OP_ZONE_RESET_ALL:
return null_zone_reset(cmd, sector);
default:
return BLK_STS_OK;
}
}
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