alistair23-linux/drivers/scsi/sd.h
Johannes Thumshirn 5795eb4430 scsi: sd_zbc: emulate ZONE_APPEND commands
Emulate ZONE_APPEND for SCSI disks using a regular WRITE(16) command
with a start LBA set to the target zone write pointer position.

In order to always know the write pointer position of a sequential write
zone, the write pointer of all zones is tracked using an array of 32bits
zone write pointer offset attached to the scsi disk structure. Each
entry of the array indicate a zone write pointer position relative to
the zone start sector. The write pointer offsets are maintained in sync
with the device as follows:
1) the write pointer offset of a zone is reset to 0 when a
   REQ_OP_ZONE_RESET command completes.
2) the write pointer offset of a zone is set to the zone size when a
   REQ_OP_ZONE_FINISH command completes.
3) the write pointer offset of a zone is incremented by the number of
   512B sectors written when a write, write same or a zone append
   command completes.
4) the write pointer offset of all zones is reset to 0 when a
   REQ_OP_ZONE_RESET_ALL command completes.

Since the block layer does not write lock zones for zone append
commands, to ensure a sequential ordering of the regular write commands
used for the emulation, the target zone of a zone append command is
locked when the function sd_zbc_prepare_zone_append() is called from
sd_setup_read_write_cmnd(). If the zone write lock cannot be obtained
(e.g. a zone append is in-flight or a regular write has already locked
the zone), the zone append command dispatching is delayed by returning
BLK_STS_ZONE_RESOURCE.

To avoid the need for write locking all zones for REQ_OP_ZONE_RESET_ALL
requests, use a spinlock to protect accesses and modifications of the
zone write pointer offsets. This spinlock is initialized from sd_probe()
using the new function sd_zbc_init().

Co-developed-by: Damien Le Moal <Damien.LeMoal@wdc.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-12 20:36:28 -06:00

281 lines
7.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _SCSI_DISK_H
#define _SCSI_DISK_H
/*
* More than enough for everybody ;) The huge number of majors
* is a leftover from 16bit dev_t days, we don't really need that
* much numberspace.
*/
#define SD_MAJORS 16
/*
* Time out in seconds for disks and Magneto-opticals (which are slower).
*/
#define SD_TIMEOUT (30 * HZ)
#define SD_MOD_TIMEOUT (75 * HZ)
/*
* Flush timeout is a multiplier over the standard device timeout which is
* user modifiable via sysfs but initially set to SD_TIMEOUT
*/
#define SD_FLUSH_TIMEOUT_MULTIPLIER 2
#define SD_WRITE_SAME_TIMEOUT (120 * HZ)
/*
* Number of allowed retries
*/
#define SD_MAX_RETRIES 5
#define SD_PASSTHROUGH_RETRIES 1
#define SD_MAX_MEDIUM_TIMEOUTS 2
/*
* Size of the initial data buffer for mode and read capacity data
*/
#define SD_BUF_SIZE 512
/*
* Number of sectors at the end of the device to avoid multi-sector
* accesses to in the case of last_sector_bug
*/
#define SD_LAST_BUGGY_SECTORS 8
enum {
SD_EXT_CDB_SIZE = 32, /* Extended CDB size */
SD_MEMPOOL_SIZE = 2, /* CDB pool size */
};
enum {
SD_DEF_XFER_BLOCKS = 0xffff,
SD_MAX_XFER_BLOCKS = 0xffffffff,
SD_MAX_WS10_BLOCKS = 0xffff,
SD_MAX_WS16_BLOCKS = 0x7fffff,
};
enum {
SD_LBP_FULL = 0, /* Full logical block provisioning */
SD_LBP_UNMAP, /* Use UNMAP command */
SD_LBP_WS16, /* Use WRITE SAME(16) with UNMAP bit */
SD_LBP_WS10, /* Use WRITE SAME(10) with UNMAP bit */
SD_LBP_ZERO, /* Use WRITE SAME(10) with zero payload */
SD_LBP_DISABLE, /* Discard disabled due to failed cmd */
};
enum {
SD_ZERO_WRITE = 0, /* Use WRITE(10/16) command */
SD_ZERO_WS, /* Use WRITE SAME(10/16) command */
SD_ZERO_WS16_UNMAP, /* Use WRITE SAME(16) with UNMAP */
SD_ZERO_WS10_UNMAP, /* Use WRITE SAME(10) with UNMAP */
};
struct scsi_disk {
struct scsi_driver *driver; /* always &sd_template */
struct scsi_device *device;
struct device dev;
struct gendisk *disk;
struct opal_dev *opal_dev;
#ifdef CONFIG_BLK_DEV_ZONED
u32 nr_zones;
u32 zone_blocks;
u32 zones_optimal_open;
u32 zones_optimal_nonseq;
u32 zones_max_open;
u32 *zones_wp_offset;
spinlock_t zones_wp_offset_lock;
u32 *rev_wp_offset;
struct mutex rev_mutex;
struct work_struct zone_wp_offset_work;
char *zone_wp_update_buf;
#endif
atomic_t openers;
sector_t capacity; /* size in logical blocks */
u32 max_xfer_blocks;
u32 opt_xfer_blocks;
u32 max_ws_blocks;
u32 max_unmap_blocks;
u32 unmap_granularity;
u32 unmap_alignment;
u32 index;
unsigned int physical_block_size;
unsigned int max_medium_access_timeouts;
unsigned int medium_access_timed_out;
u8 media_present;
u8 write_prot;
u8 protection_type;/* Data Integrity Field */
u8 provisioning_mode;
u8 zeroing_mode;
unsigned ATO : 1; /* state of disk ATO bit */
unsigned cache_override : 1; /* temp override of WCE,RCD */
unsigned WCE : 1; /* state of disk WCE bit */
unsigned RCD : 1; /* state of disk RCD bit, unused */
unsigned DPOFUA : 1; /* state of disk DPOFUA bit */
unsigned first_scan : 1;
unsigned lbpme : 1;
unsigned lbprz : 1;
unsigned lbpu : 1;
unsigned lbpws : 1;
unsigned lbpws10 : 1;
unsigned lbpvpd : 1;
unsigned ws10 : 1;
unsigned ws16 : 1;
unsigned rc_basis: 2;
unsigned zoned: 2;
unsigned urswrz : 1;
unsigned security : 1;
unsigned ignore_medium_access_errors : 1;
};
#define to_scsi_disk(obj) container_of(obj,struct scsi_disk,dev)
static inline struct scsi_disk *scsi_disk(struct gendisk *disk)
{
return container_of(disk->private_data, struct scsi_disk, driver);
}
#define sd_printk(prefix, sdsk, fmt, a...) \
(sdsk)->disk ? \
sdev_prefix_printk(prefix, (sdsk)->device, \
(sdsk)->disk->disk_name, fmt, ##a) : \
sdev_printk(prefix, (sdsk)->device, fmt, ##a)
#define sd_first_printk(prefix, sdsk, fmt, a...) \
do { \
if ((sdsk)->first_scan) \
sd_printk(prefix, sdsk, fmt, ##a); \
} while (0)
static inline int scsi_medium_access_command(struct scsi_cmnd *scmd)
{
switch (scmd->cmnd[0]) {
case READ_6:
case READ_10:
case READ_12:
case READ_16:
case SYNCHRONIZE_CACHE:
case VERIFY:
case VERIFY_12:
case VERIFY_16:
case WRITE_6:
case WRITE_10:
case WRITE_12:
case WRITE_16:
case WRITE_SAME:
case WRITE_SAME_16:
case UNMAP:
return 1;
case VARIABLE_LENGTH_CMD:
switch (scmd->cmnd[9]) {
case READ_32:
case VERIFY_32:
case WRITE_32:
case WRITE_SAME_32:
return 1;
}
}
return 0;
}
static inline sector_t logical_to_sectors(struct scsi_device *sdev, sector_t blocks)
{
return blocks << (ilog2(sdev->sector_size) - 9);
}
static inline unsigned int logical_to_bytes(struct scsi_device *sdev, sector_t blocks)
{
return blocks * sdev->sector_size;
}
static inline sector_t bytes_to_logical(struct scsi_device *sdev, unsigned int bytes)
{
return bytes >> ilog2(sdev->sector_size);
}
static inline sector_t sectors_to_logical(struct scsi_device *sdev, sector_t sector)
{
return sector >> (ilog2(sdev->sector_size) - 9);
}
#ifdef CONFIG_BLK_DEV_INTEGRITY
extern void sd_dif_config_host(struct scsi_disk *);
#else /* CONFIG_BLK_DEV_INTEGRITY */
static inline void sd_dif_config_host(struct scsi_disk *disk)
{
}
#endif /* CONFIG_BLK_DEV_INTEGRITY */
static inline int sd_is_zoned(struct scsi_disk *sdkp)
{
return sdkp->zoned == 1 || sdkp->device->type == TYPE_ZBC;
}
#ifdef CONFIG_BLK_DEV_ZONED
int sd_zbc_init_disk(struct scsi_disk *sdkp);
void sd_zbc_release_disk(struct scsi_disk *sdkp);
extern int sd_zbc_read_zones(struct scsi_disk *sdkp, unsigned char *buffer);
extern void sd_zbc_print_zones(struct scsi_disk *sdkp);
blk_status_t sd_zbc_setup_zone_mgmt_cmnd(struct scsi_cmnd *cmd,
unsigned char op, bool all);
unsigned int sd_zbc_complete(struct scsi_cmnd *cmd, unsigned int good_bytes,
struct scsi_sense_hdr *sshdr);
int sd_zbc_report_zones(struct gendisk *disk, sector_t sector,
unsigned int nr_zones, report_zones_cb cb, void *data);
blk_status_t sd_zbc_prepare_zone_append(struct scsi_cmnd *cmd, sector_t *lba,
unsigned int nr_blocks);
#else /* CONFIG_BLK_DEV_ZONED */
static inline int sd_zbc_init(void)
{
return 0;
}
static inline int sd_zbc_init_disk(struct scsi_disk *sdkp)
{
return 0;
}
static inline void sd_zbc_exit(void) {}
static inline void sd_zbc_release_disk(struct scsi_disk *sdkp) {}
static inline int sd_zbc_read_zones(struct scsi_disk *sdkp,
unsigned char *buf)
{
return 0;
}
static inline void sd_zbc_print_zones(struct scsi_disk *sdkp) {}
static inline blk_status_t sd_zbc_setup_zone_mgmt_cmnd(struct scsi_cmnd *cmd,
unsigned char op,
bool all)
{
return BLK_STS_TARGET;
}
static inline unsigned int sd_zbc_complete(struct scsi_cmnd *cmd,
unsigned int good_bytes, struct scsi_sense_hdr *sshdr)
{
return 0;
}
static inline blk_status_t sd_zbc_prepare_zone_append(struct scsi_cmnd *cmd,
sector_t *lba,
unsigned int nr_blocks)
{
return BLK_STS_TARGET;
}
#define sd_zbc_report_zones NULL
#endif /* CONFIG_BLK_DEV_ZONED */
void sd_print_sense_hdr(struct scsi_disk *sdkp, struct scsi_sense_hdr *sshdr);
void sd_print_result(const struct scsi_disk *sdkp, const char *msg, int result);
#endif /* _SCSI_DISK_H */