linux/drivers/scsi/sd_zbc.c

511 lines
13 KiB
C

/*
* SCSI Zoned Block commands
*
* Copyright (C) 2014-2015 SUSE Linux GmbH
* Written by: Hannes Reinecke <hare@suse.de>
* Modified by: Damien Le Moal <damien.lemoal@hgst.com>
* Modified by: Shaun Tancheff <shaun.tancheff@seagate.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; see the file COPYING. If not, write to
* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
* USA.
*
*/
#include <linux/blkdev.h>
#include <asm/unaligned.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include "sd.h"
/**
* sd_zbc_parse_report - Convert a zone descriptor to a struct blk_zone,
* @sdkp: The disk the report originated from
* @buf: Address of the report zone descriptor
* @zone: the destination zone structure
*
* All LBA sized values are converted to 512B sectors unit.
*/
static void sd_zbc_parse_report(struct scsi_disk *sdkp, u8 *buf,
struct blk_zone *zone)
{
struct scsi_device *sdp = sdkp->device;
memset(zone, 0, sizeof(struct blk_zone));
zone->type = buf[0] & 0x0f;
zone->cond = (buf[1] >> 4) & 0xf;
if (buf[1] & 0x01)
zone->reset = 1;
if (buf[1] & 0x02)
zone->non_seq = 1;
zone->len = logical_to_sectors(sdp, get_unaligned_be64(&buf[8]));
zone->start = logical_to_sectors(sdp, get_unaligned_be64(&buf[16]));
zone->wp = logical_to_sectors(sdp, get_unaligned_be64(&buf[24]));
if (zone->type != ZBC_ZONE_TYPE_CONV &&
zone->cond == ZBC_ZONE_COND_FULL)
zone->wp = zone->start + zone->len;
}
/**
* sd_zbc_do_report_zones - Issue a REPORT ZONES scsi command.
* @sdkp: The target disk
* @buf: Buffer to use for the reply
* @buflen: the buffer size
* @lba: Start LBA of the report
* @partial: Do partial report
*
* For internal use during device validation.
* Using partial=true can significantly speed up execution of a report zones
* command because the disk does not have to count all possible report matching
* zones and will only report the count of zones fitting in the command reply
* buffer.
*/
static int sd_zbc_do_report_zones(struct scsi_disk *sdkp, unsigned char *buf,
unsigned int buflen, sector_t lba,
bool partial)
{
struct scsi_device *sdp = sdkp->device;
const int timeout = sdp->request_queue->rq_timeout;
struct scsi_sense_hdr sshdr;
unsigned char cmd[16];
unsigned int rep_len;
int result;
memset(cmd, 0, 16);
cmd[0] = ZBC_IN;
cmd[1] = ZI_REPORT_ZONES;
put_unaligned_be64(lba, &cmd[2]);
put_unaligned_be32(buflen, &cmd[10]);
if (partial)
cmd[14] = ZBC_REPORT_ZONE_PARTIAL;
memset(buf, 0, buflen);
result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
buf, buflen, &sshdr,
timeout, SD_MAX_RETRIES, NULL);
if (result) {
sd_printk(KERN_ERR, sdkp,
"REPORT ZONES lba %llu failed with %d/%d\n",
(unsigned long long)lba,
host_byte(result), driver_byte(result));
return -EIO;
}
rep_len = get_unaligned_be32(&buf[0]);
if (rep_len < 64) {
sd_printk(KERN_ERR, sdkp,
"REPORT ZONES report invalid length %u\n",
rep_len);
return -EIO;
}
return 0;
}
/**
* sd_zbc_report_zones - Disk report zones operation.
* @disk: The target disk
* @sector: Start 512B sector of the report
* @zones: Array of zone descriptors
* @nr_zones: Number of descriptors in the array
* @gfp_mask: Memory allocation mask
*
* Execute a report zones command on the target disk.
*/
int sd_zbc_report_zones(struct gendisk *disk, sector_t sector,
struct blk_zone *zones, unsigned int *nr_zones,
gfp_t gfp_mask)
{
struct scsi_disk *sdkp = scsi_disk(disk);
unsigned int i, buflen, nrz = *nr_zones;
unsigned char *buf;
size_t offset = 0;
int ret = 0;
if (!sd_is_zoned(sdkp))
/* Not a zoned device */
return -EOPNOTSUPP;
/*
* Get a reply buffer for the number of requested zones plus a header,
* without exceeding the device maximum command size. For ATA disks,
* buffers must be aligned to 512B.
*/
buflen = min(queue_max_hw_sectors(disk->queue) << 9,
roundup((nrz + 1) * 64, 512));
buf = kmalloc(buflen, gfp_mask);
if (!buf)
return -ENOMEM;
ret = sd_zbc_do_report_zones(sdkp, buf, buflen,
sectors_to_logical(sdkp->device, sector), true);
if (ret)
goto out_free_buf;
nrz = min(nrz, get_unaligned_be32(&buf[0]) / 64);
for (i = 0; i < nrz; i++) {
offset += 64;
sd_zbc_parse_report(sdkp, buf + offset, zones);
zones++;
}
*nr_zones = nrz;
out_free_buf:
kfree(buf);
return ret;
}
/**
* sd_zbc_zone_sectors - Get the device zone size in number of 512B sectors.
* @sdkp: The target disk
*/
static inline sector_t sd_zbc_zone_sectors(struct scsi_disk *sdkp)
{
return logical_to_sectors(sdkp->device, sdkp->zone_blocks);
}
/**
* sd_zbc_setup_reset_cmnd - Prepare a RESET WRITE POINTER scsi command.
* @cmd: the command to setup
*
* Called from sd_init_command() for a REQ_OP_ZONE_RESET request.
*/
blk_status_t sd_zbc_setup_reset_cmnd(struct scsi_cmnd *cmd)
{
struct request *rq = cmd->request;
struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
sector_t sector = blk_rq_pos(rq);
sector_t block = sectors_to_logical(sdkp->device, sector);
if (!sd_is_zoned(sdkp))
/* Not a zoned device */
return BLK_STS_IOERR;
if (sdkp->device->changed)
return BLK_STS_IOERR;
if (sector & (sd_zbc_zone_sectors(sdkp) - 1))
/* Unaligned request */
return BLK_STS_IOERR;
cmd->cmd_len = 16;
memset(cmd->cmnd, 0, cmd->cmd_len);
cmd->cmnd[0] = ZBC_OUT;
cmd->cmnd[1] = ZO_RESET_WRITE_POINTER;
put_unaligned_be64(block, &cmd->cmnd[2]);
rq->timeout = SD_TIMEOUT;
cmd->sc_data_direction = DMA_NONE;
cmd->transfersize = 0;
cmd->allowed = 0;
return BLK_STS_OK;
}
/**
* sd_zbc_complete - ZBC command post processing.
* @cmd: Completed command
* @good_bytes: Command reply bytes
* @sshdr: command sense header
*
* Called from sd_done(). Process report zones reply and handle reset zone
* and write commands errors.
*/
void sd_zbc_complete(struct scsi_cmnd *cmd, unsigned int good_bytes,
struct scsi_sense_hdr *sshdr)
{
int result = cmd->result;
struct request *rq = cmd->request;
switch (req_op(rq)) {
case REQ_OP_ZONE_RESET:
if (result &&
sshdr->sense_key == ILLEGAL_REQUEST &&
sshdr->asc == 0x24)
/*
* INVALID FIELD IN CDB error: reset of a conventional
* zone was attempted. Nothing to worry about, so be
* quiet about the error.
*/
rq->rq_flags |= RQF_QUIET;
break;
case REQ_OP_WRITE:
case REQ_OP_WRITE_ZEROES:
case REQ_OP_WRITE_SAME:
break;
}
}
/**
* sd_zbc_check_zoned_characteristics - Check zoned block device characteristics
* @sdkp: Target disk
* @buf: Buffer where to store the VPD page data
*
* Read VPD page B6, get information and check that reads are unconstrained.
*/
static int sd_zbc_check_zoned_characteristics(struct scsi_disk *sdkp,
unsigned char *buf)
{
if (scsi_get_vpd_page(sdkp->device, 0xb6, buf, 64)) {
sd_printk(KERN_NOTICE, sdkp,
"Read zoned characteristics VPD page failed\n");
return -ENODEV;
}
if (sdkp->device->type != TYPE_ZBC) {
/* Host-aware */
sdkp->urswrz = 1;
sdkp->zones_optimal_open = get_unaligned_be32(&buf[8]);
sdkp->zones_optimal_nonseq = get_unaligned_be32(&buf[12]);
sdkp->zones_max_open = 0;
} else {
/* Host-managed */
sdkp->urswrz = buf[4] & 1;
sdkp->zones_optimal_open = 0;
sdkp->zones_optimal_nonseq = 0;
sdkp->zones_max_open = get_unaligned_be32(&buf[16]);
}
/*
* Check for unconstrained reads: host-managed devices with
* constrained reads (drives failing read after write pointer)
* are not supported.
*/
if (!sdkp->urswrz) {
if (sdkp->first_scan)
sd_printk(KERN_NOTICE, sdkp,
"constrained reads devices are not supported\n");
return -ENODEV;
}
return 0;
}
#define SD_ZBC_BUF_SIZE 131072U
/**
* sd_zbc_check_zones - Check the device capacity and zone sizes
* @sdkp: Target disk
*
* Check that the device capacity as reported by READ CAPACITY matches the
* max_lba value (plus one)of the report zones command reply. Also check that
* all zones of the device have an equal size, only allowing the last zone of
* the disk to have a smaller size (runt zone). The zone size must also be a
* power of two.
*
* Returns the zone size in number of blocks upon success or an error code
* upon failure.
*/
static int sd_zbc_check_zones(struct scsi_disk *sdkp, u32 *zblocks)
{
u64 zone_blocks = 0;
sector_t max_lba, block = 0;
unsigned char *buf;
unsigned char *rec;
unsigned int buf_len;
unsigned int list_length;
int ret;
u8 same;
/* Get a buffer */
buf = kmalloc(SD_ZBC_BUF_SIZE, GFP_KERNEL);
if (!buf)
return -ENOMEM;
/* Do a report zone to get max_lba and the same field */
ret = sd_zbc_do_report_zones(sdkp, buf, SD_ZBC_BUF_SIZE, 0, false);
if (ret)
goto out_free;
if (sdkp->rc_basis == 0) {
/* The max_lba field is the capacity of this device */
max_lba = get_unaligned_be64(&buf[8]);
if (sdkp->capacity != max_lba + 1) {
if (sdkp->first_scan)
sd_printk(KERN_WARNING, sdkp,
"Changing capacity from %llu to max LBA+1 %llu\n",
(unsigned long long)sdkp->capacity,
(unsigned long long)max_lba + 1);
sdkp->capacity = max_lba + 1;
}
}
/*
* Check same field: for any value other than 0, we know that all zones
* have the same size.
*/
same = buf[4] & 0x0f;
if (same > 0) {
rec = &buf[64];
zone_blocks = get_unaligned_be64(&rec[8]);
goto out;
}
/*
* Check the size of all zones: all zones must be of
* equal size, except the last zone which can be smaller
* than other zones.
*/
do {
/* Parse REPORT ZONES header */
list_length = get_unaligned_be32(&buf[0]) + 64;
rec = buf + 64;
buf_len = min(list_length, SD_ZBC_BUF_SIZE);
/* Parse zone descriptors */
while (rec < buf + buf_len) {
u64 this_zone_blocks = get_unaligned_be64(&rec[8]);
if (zone_blocks == 0) {
zone_blocks = this_zone_blocks;
} else if (this_zone_blocks != zone_blocks &&
(block + this_zone_blocks < sdkp->capacity
|| this_zone_blocks > zone_blocks)) {
zone_blocks = 0;
goto out;
}
block += this_zone_blocks;
rec += 64;
}
if (block < sdkp->capacity) {
ret = sd_zbc_do_report_zones(sdkp, buf, SD_ZBC_BUF_SIZE,
block, true);
if (ret)
goto out_free;
}
} while (block < sdkp->capacity);
out:
if (!zone_blocks) {
if (sdkp->first_scan)
sd_printk(KERN_NOTICE, sdkp,
"Devices with non constant zone "
"size are not supported\n");
ret = -ENODEV;
} else if (!is_power_of_2(zone_blocks)) {
if (sdkp->first_scan)
sd_printk(KERN_NOTICE, sdkp,
"Devices with non power of 2 zone "
"size are not supported\n");
ret = -ENODEV;
} else if (logical_to_sectors(sdkp->device, zone_blocks) > UINT_MAX) {
if (sdkp->first_scan)
sd_printk(KERN_NOTICE, sdkp,
"Zone size too large\n");
ret = -EFBIG;
} else {
*zblocks = zone_blocks;
ret = 0;
}
out_free:
kfree(buf);
return ret;
}
int sd_zbc_read_zones(struct scsi_disk *sdkp, unsigned char *buf)
{
struct gendisk *disk = sdkp->disk;
unsigned int nr_zones;
u32 zone_blocks;
int ret;
if (!sd_is_zoned(sdkp))
/*
* Device managed or normal SCSI disk,
* no special handling required
*/
return 0;
/* Check zoned block device characteristics (unconstrained reads) */
ret = sd_zbc_check_zoned_characteristics(sdkp, buf);
if (ret)
goto err;
/*
* Check zone size: only devices with a constant zone size (except
* an eventual last runt zone) that is a power of 2 are supported.
*/
ret = sd_zbc_check_zones(sdkp, &zone_blocks);
if (ret != 0)
goto err;
/* The drive satisfies the kernel restrictions: set it up */
blk_queue_chunk_sectors(sdkp->disk->queue,
logical_to_sectors(sdkp->device, zone_blocks));
nr_zones = round_up(sdkp->capacity, zone_blocks) >> ilog2(zone_blocks);
/* READ16/WRITE16 is mandatory for ZBC disks */
sdkp->device->use_16_for_rw = 1;
sdkp->device->use_10_for_rw = 0;
/*
* Revalidate the disk zone bitmaps once the block device capacity is
* set on the second revalidate execution during disk scan and if
* something changed when executing a normal revalidate.
*/
if (sdkp->first_scan) {
sdkp->zone_blocks = zone_blocks;
sdkp->nr_zones = nr_zones;
return 0;
}
if (sdkp->zone_blocks != zone_blocks ||
sdkp->nr_zones != nr_zones ||
disk->queue->nr_zones != nr_zones) {
ret = blk_revalidate_disk_zones(disk);
if (ret != 0)
goto err;
sdkp->zone_blocks = zone_blocks;
sdkp->nr_zones = nr_zones;
}
return 0;
err:
sdkp->capacity = 0;
return ret;
}
void sd_zbc_print_zones(struct scsi_disk *sdkp)
{
if (!sd_is_zoned(sdkp) || !sdkp->capacity)
return;
if (sdkp->capacity & (sdkp->zone_blocks - 1))
sd_printk(KERN_NOTICE, sdkp,
"%u zones of %u logical blocks + 1 runt zone\n",
sdkp->nr_zones - 1,
sdkp->zone_blocks);
else
sd_printk(KERN_NOTICE, sdkp,
"%u zones of %u logical blocks\n",
sdkp->nr_zones,
sdkp->zone_blocks);
}