1 files changed, 641 insertions, 0 deletions

diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c
new file mode 100644
index 000000000000..56e455fb5add
--- /dev/null
+++ b/drivers/scsi/sd_zbc.c
@@ -0,0 +1,641 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * 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>
+ */
+
+#include <linux/blkdev.h>
+#include <linux/vmalloc.h>
+#include <linux/sched/mm.h>
+#include <linux/mutex.h>
+
+#include <linux/unaligned.h>
+
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+
+#include "sd.h"
+
+#define CREATE_TRACE_POINTS
+#include "sd_trace.h"
+
+/* Whether or not a SCSI zone descriptor describes a gap zone. */
+static bool sd_zbc_is_gap_zone(const u8 buf[64])
+{
+	return (buf[0] & 0xf) == ZBC_ZONE_TYPE_GAP;
+}
+
+/**
+ * sd_zbc_parse_report - Parse a SCSI zone descriptor
+ * @sdkp: SCSI disk pointer.
+ * @buf: SCSI zone descriptor.
+ * @idx: Index of the zone relative to the first zone reported by the current
+ *	sd_zbc_report_zones() call.
+ * @args: report zones arguments (callback, etc)
+ *
+ * Return: Value returned by @cb.
+ *
+ * Convert a SCSI zone descriptor into struct blk_zone format. Additionally,
+ * call @cb(blk_zone, @data).
+ */
+static int sd_zbc_parse_report(struct scsi_disk *sdkp, const u8 buf[64],
+			unsigned int idx, struct blk_report_zones_args *args)
+{
+	struct scsi_device *sdp = sdkp->device;
+	struct blk_zone zone = { 0 };
+	sector_t start_lba, gran;
+
+	if (WARN_ON_ONCE(sd_zbc_is_gap_zone(buf)))
+		return -EINVAL;
+
+	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;
+
+	start_lba = get_unaligned_be64(&buf[16]);
+	zone.start = logical_to_sectors(sdp, start_lba);
+	zone.capacity = logical_to_sectors(sdp, get_unaligned_be64(&buf[8]));
+	zone.len = zone.capacity;
+	if (sdkp->zone_starting_lba_gran) {
+		gran = logical_to_sectors(sdp, sdkp->zone_starting_lba_gran);
+		if (zone.len > gran) {
+			sd_printk(KERN_ERR, sdkp,
+				  "Invalid zone at LBA %llu with capacity %llu and length %llu; granularity = %llu\n",
+				  start_lba,
+				  sectors_to_logical(sdp, zone.capacity),
+				  sectors_to_logical(sdp, zone.len),
+				  sectors_to_logical(sdp, gran));
+			return -EINVAL;
+		}
+		/*
+		 * Use the starting LBA granularity instead of the zone length
+		 * obtained from the REPORT ZONES command.
+		 */
+		zone.len = gran;
+	}
+	if (zone.cond == ZBC_ZONE_COND_FULL)
+		zone.wp = zone.start + zone.len;
+	else
+		zone.wp = logical_to_sectors(sdp, get_unaligned_be64(&buf[24]));
+
+	return disk_report_zone(sdkp->disk, &zone, idx, args);
+}
+
+/**
+ * sd_zbc_do_report_zones - Issue a REPORT ZONES scsi command.
+ * @sdkp: The target disk
+ * @buf: vmalloc-ed 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;
+	const struct scsi_exec_args exec_args = {
+		.sshdr = &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;
+
+	result = scsi_execute_cmd(sdp, cmd, REQ_OP_DRV_IN, buf, buflen,
+				  timeout, SD_MAX_RETRIES, &exec_args);
+	if (result) {
+		sd_printk(KERN_ERR, sdkp,
+			  "REPORT ZONES start lba %llu failed\n", lba);
+		sd_print_result(sdkp, "REPORT ZONES", result);
+		if (result > 0 && scsi_sense_valid(&sshdr))
+			sd_print_sense_hdr(sdkp, &sshdr);
+		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_alloc_report_buffer() - Allocate a buffer for report zones reply.
+ * @sdkp: The target disk
+ * @nr_zones: Maximum number of zones to report
+ * @buflen: Size of the buffer allocated
+ *
+ * Try to allocate a reply buffer for the number of requested zones.
+ * The size of the buffer allocated may be smaller than requested to
+ * satify the device constraint (max_hw_sectors, max_segments, etc).
+ *
+ * Return the address of the allocated buffer and update @buflen with
+ * the size of the allocated buffer.
+ */
+static void *sd_zbc_alloc_report_buffer(struct scsi_disk *sdkp,
+					unsigned int nr_zones, size_t *buflen)
+{
+	struct request_queue *q = sdkp->disk->queue;
+	unsigned int max_segments;
+	size_t bufsize;
+	void *buf;
+
+	/*
+	 * Report zone buffer size should be at most 64B times the number of
+	 * zones requested plus the 64B reply header, but should be aligned
+	 * to SECTOR_SIZE for ATA devices.
+	 * Make sure that this size does not exceed the hardware capabilities.
+	 * Furthermore, since the report zone command cannot be split, make
+	 * sure that the allocated buffer can always be mapped by limiting the
+	 * number of pages allocated to the HBA max segments limit.
+	 * Since max segments can be larger than the max inline bio vectors,
+	 * further limit the allocated buffer to BIO_MAX_INLINE_VECS.
+	 */
+	nr_zones = min(nr_zones, sdkp->zone_info.nr_zones);
+	bufsize = roundup((nr_zones + 1) * 64, SECTOR_SIZE);
+	bufsize = min_t(size_t, bufsize,
+			queue_max_hw_sectors(q) << SECTOR_SHIFT);
+	max_segments = min(BIO_MAX_INLINE_VECS, queue_max_segments(q));
+	bufsize = min_t(size_t, bufsize, max_segments << PAGE_SHIFT);
+
+	while (bufsize >= SECTOR_SIZE) {
+		buf = kvzalloc(bufsize, GFP_KERNEL | __GFP_NORETRY);
+		if (buf) {
+			*buflen = bufsize;
+			return buf;
+		}
+		bufsize = rounddown(bufsize >> 1, SECTOR_SIZE);
+	}
+
+	return NULL;
+}
+
+/**
+ * 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_info.zone_blocks);
+}
+
+/**
+ * sd_zbc_report_zones - SCSI .report_zones() callback.
+ * @disk: Disk to report zones for.
+ * @sector: Start sector.
+ * @nr_zones: Maximum number of zones to report.
+ * @args: Callback arguments.
+ *
+ * Called by the block layer to iterate over zone information. See also the
+ * disk->fops->report_zones() calls in block/blk-zoned.c.
+ */
+int sd_zbc_report_zones(struct gendisk *disk, sector_t sector,
+			unsigned int nr_zones,
+			struct blk_report_zones_args *args)
+{
+	struct scsi_disk *sdkp = scsi_disk(disk);
+	sector_t lba = sectors_to_logical(sdkp->device, sector);
+	unsigned int nr, i;
+	unsigned char *buf;
+	u64 zone_length, start_lba;
+	size_t offset, buflen = 0;
+	int zone_idx = 0;
+	int ret;
+
+	if (sdkp->device->type != TYPE_ZBC)
+		/* Not a zoned device */
+		return -EOPNOTSUPP;
+
+	if (!sdkp->capacity)
+		/* Device gone or invalid */
+		return -ENODEV;
+
+	buf = sd_zbc_alloc_report_buffer(sdkp, nr_zones, &buflen);
+	if (!buf)
+		return -ENOMEM;
+
+	while (zone_idx < nr_zones && lba < sdkp->capacity) {
+		ret = sd_zbc_do_report_zones(sdkp, buf, buflen, lba, true);
+		if (ret)
+			goto out;
+
+		offset = 0;
+		nr = min(nr_zones, get_unaligned_be32(&buf[0]) / 64);
+		if (!nr)
+			break;
+
+		for (i = 0; i < nr && zone_idx < nr_zones; i++) {
+			offset += 64;
+			start_lba = get_unaligned_be64(&buf[offset + 16]);
+			zone_length = get_unaligned_be64(&buf[offset + 8]);
+			if ((zone_idx == 0 &&
+			    (lba < start_lba ||
+			     lba >= start_lba + zone_length)) ||
+			    (zone_idx > 0 && start_lba != lba) ||
+			    start_lba + zone_length < start_lba) {
+				sd_printk(KERN_ERR, sdkp,
+					  "Zone %d at LBA %llu is invalid: %llu + %llu\n",
+					  zone_idx, lba, start_lba, zone_length);
+				ret = -EINVAL;
+				goto out;
+			}
+			lba = start_lba + zone_length;
+			if (sd_zbc_is_gap_zone(&buf[offset])) {
+				if (sdkp->zone_starting_lba_gran)
+					continue;
+				sd_printk(KERN_ERR, sdkp,
+					  "Gap zone without constant LBA offsets\n");
+				ret = -EINVAL;
+				goto out;
+			}
+
+			ret = sd_zbc_parse_report(sdkp, buf + offset, zone_idx,
+						  args);
+			if (ret)
+				goto out;
+
+			zone_idx++;
+		}
+	}
+
+	ret = zone_idx;
+out:
+	kvfree(buf);
+	return ret;
+}
+
+static blk_status_t sd_zbc_cmnd_checks(struct scsi_cmnd *cmd)
+{
+	struct request *rq = scsi_cmd_to_rq(cmd);
+	struct scsi_disk *sdkp = scsi_disk(rq->q->disk);
+	sector_t sector = blk_rq_pos(rq);
+
+	if (sdkp->device->type != TYPE_ZBC)
+		/* 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;
+
+	return BLK_STS_OK;
+}
+
+/**
+ * sd_zbc_setup_zone_mgmt_cmnd - Prepare a zone ZBC_OUT command. The operations
+ *			can be RESET WRITE POINTER, OPEN, CLOSE or FINISH.
+ * @cmd: the command to setup
+ * @op: Operation to be performed
+ * @all: All zones control
+ *
+ * Called from sd_init_command() for REQ_OP_ZONE_RESET, REQ_OP_ZONE_RESET_ALL,
+ * REQ_OP_ZONE_OPEN, REQ_OP_ZONE_CLOSE or REQ_OP_ZONE_FINISH requests.
+ */
+blk_status_t sd_zbc_setup_zone_mgmt_cmnd(struct scsi_cmnd *cmd,
+					 unsigned char op, bool all)
+{
+	struct request *rq = scsi_cmd_to_rq(cmd);
+	sector_t sector = blk_rq_pos(rq);
+	struct scsi_disk *sdkp = scsi_disk(rq->q->disk);
+	sector_t block = sectors_to_logical(sdkp->device, sector);
+	blk_status_t ret;
+
+	ret = sd_zbc_cmnd_checks(cmd);
+	if (ret != BLK_STS_OK)
+		return ret;
+
+	cmd->cmd_len = 16;
+	memset(cmd->cmnd, 0, cmd->cmd_len);
+	cmd->cmnd[0] = ZBC_OUT;
+	cmd->cmnd[1] = op;
+	if (all)
+		cmd->cmnd[14] = 0x1;
+	else
+		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() to handle zone commands errors and updates to the
+ * device queue zone write pointer offset cahce.
+ */
+unsigned int sd_zbc_complete(struct scsi_cmnd *cmd, unsigned int good_bytes,
+		     struct scsi_sense_hdr *sshdr)
+{
+	int result = cmd->result;
+	struct request *rq = scsi_cmd_to_rq(cmd);
+
+	if (op_is_zone_mgmt(req_op(rq)) &&
+	    result &&
+	    sshdr->sense_key == ILLEGAL_REQUEST &&
+	    sshdr->asc == 0x24) {
+		/*
+		 * INVALID FIELD IN CDB error: a zone management command was
+		 * attempted on a conventional zone. Nothing to worry about,
+		 * so be quiet about the error.
+		 */
+		rq->rq_flags |= RQF_QUIET;
+	}
+
+	return good_bytes;
+}
+
+/**
+ * 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)
+{
+	u64 zone_starting_lba_gran;
+
+	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;
+		return 0;
+	}
+
+	/* 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 zone alignment method */
+	switch (buf[23] & 0xf) {
+	case 0:
+	case ZBC_CONSTANT_ZONE_LENGTH:
+		/* Use zone length */
+		break;
+	case ZBC_CONSTANT_ZONE_START_OFFSET:
+		zone_starting_lba_gran = get_unaligned_be64(&buf[24]);
+		if (zone_starting_lba_gran == 0 ||
+		    !is_power_of_2(zone_starting_lba_gran) ||
+		    logical_to_sectors(sdkp->device, zone_starting_lba_gran) >
+		    UINT_MAX) {
+			sd_printk(KERN_ERR, sdkp,
+				  "Invalid zone starting LBA granularity %llu\n",
+				  zone_starting_lba_gran);
+			return -ENODEV;
+		}
+		sdkp->zone_starting_lba_gran = zone_starting_lba_gran;
+		break;
+	default:
+		sd_printk(KERN_ERR, sdkp, "Invalid zone alignment method\n");
+		return -ENODEV;
+	}
+
+	/*
+	 * 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;
+}
+
+/**
+ * sd_zbc_check_capacity - Check the device capacity
+ * @sdkp: Target disk
+ * @buf: command buffer
+ * @zblocks: zone size in logical blocks
+ *
+ * Get the device zone size and check that the device capacity as reported
+ * by READ CAPACITY matches the max_lba value (plus one) of the report zones
+ * command reply for devices with RC_BASIS == 0.
+ *
+ * Returns 0 upon success or an error code upon failure.
+ */
+static int sd_zbc_check_capacity(struct scsi_disk *sdkp, unsigned char *buf,
+				 u32 *zblocks)
+{
+	u64 zone_blocks;
+	sector_t max_lba;
+	unsigned char *rec;
+	int ret;
+
+	/* Do a report zone to get max_lba and the size of the first zone */
+	ret = sd_zbc_do_report_zones(sdkp, buf, SD_BUF_SIZE, 0, false);
+	if (ret)
+		return ret;
+
+	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;
+		}
+	}
+
+	if (sdkp->zone_starting_lba_gran == 0) {
+		/* Get the size of the first reported zone */
+		rec = buf + 64;
+		zone_blocks = get_unaligned_be64(&rec[8]);
+		if (logical_to_sectors(sdkp->device, zone_blocks) > UINT_MAX) {
+			if (sdkp->first_scan)
+				sd_printk(KERN_NOTICE, sdkp,
+					  "Zone size too large\n");
+			return -EFBIG;
+		}
+	} else {
+		zone_blocks = sdkp->zone_starting_lba_gran;
+	}
+
+	if (!is_power_of_2(zone_blocks)) {
+		sd_printk(KERN_ERR, sdkp,
+			  "Zone size %llu is not a power of two.\n",
+			  zone_blocks);
+		return -EINVAL;
+	}
+
+	*zblocks = zone_blocks;
+
+	return 0;
+}
+
+static void sd_zbc_print_zones(struct scsi_disk *sdkp)
+{
+	if (sdkp->device->type != TYPE_ZBC || !sdkp->capacity)
+		return;
+
+	if (sdkp->capacity & (sdkp->zone_info.zone_blocks - 1))
+		sd_printk(KERN_NOTICE, sdkp,
+			  "%u zones of %u logical blocks + 1 runt zone\n",
+			  sdkp->zone_info.nr_zones - 1,
+			  sdkp->zone_info.zone_blocks);
+	else
+		sd_printk(KERN_NOTICE, sdkp,
+			  "%u zones of %u logical blocks\n",
+			  sdkp->zone_info.nr_zones,
+			  sdkp->zone_info.zone_blocks);
+}
+
+/*
+ * Call blk_revalidate_disk_zones() if any of the zoned disk properties have
+ * changed that make it necessary to call that function. Called by
+ * sd_revalidate_disk() after the gendisk capacity has been set.
+ */
+int sd_zbc_revalidate_zones(struct scsi_disk *sdkp)
+{
+	struct gendisk *disk = sdkp->disk;
+	struct request_queue *q = disk->queue;
+	u32 zone_blocks = sdkp->early_zone_info.zone_blocks;
+	unsigned int nr_zones = sdkp->early_zone_info.nr_zones;
+	unsigned int flags;
+	int ret;
+
+	/*
+	 * There is nothing to do for regular disks, including host-aware disks
+	 * that have partitions.
+	 */
+	if (!blk_queue_is_zoned(q))
+		return 0;
+
+	if (sdkp->zone_info.zone_blocks == zone_blocks &&
+	    sdkp->zone_info.nr_zones == nr_zones &&
+	    disk->nr_zones == nr_zones)
+		return 0;
+
+	sdkp->zone_info.zone_blocks = zone_blocks;
+	sdkp->zone_info.nr_zones = nr_zones;
+
+	flags = memalloc_noio_save();
+	ret = blk_revalidate_disk_zones(disk);
+	memalloc_noio_restore(flags);
+	if (ret) {
+		sdkp->zone_info = (struct zoned_disk_info){ };
+		sdkp->capacity = 0;
+		return ret;
+	}
+
+	sd_zbc_print_zones(sdkp);
+
+	return 0;
+}
+
+/**
+ * sd_zbc_read_zones - Read zone information and update the request queue
+ * @sdkp: SCSI disk pointer.
+ * @lim: queue limits to read into
+ * @buf: 512 byte buffer used for storing SCSI command output.
+ *
+ * Read zone information and update the request queue zone characteristics and
+ * also the zoned device information in *sdkp. Called by sd_revalidate_disk()
+ * before the gendisk capacity has been set.
+ */
+int sd_zbc_read_zones(struct scsi_disk *sdkp, struct queue_limits *lim,
+		u8 buf[SD_BUF_SIZE])
+{
+	unsigned int nr_zones;
+	u32 zone_blocks = 0;
+	int ret;
+
+	if (sdkp->device->type != TYPE_ZBC)
+		return 0;
+
+	lim->features |= BLK_FEAT_ZONED;
+
+	/*
+	 * Per ZBC and ZAC specifications, writes in sequential write required
+	 * zones of host-managed devices must be aligned to the device physical
+	 * block size.
+	 */
+	lim->zone_write_granularity = sdkp->physical_block_size;
+
+	/* READ16/WRITE16/SYNC16 is mandatory for ZBC devices */
+	sdkp->device->use_16_for_rw = 1;
+	sdkp->device->use_10_for_rw = 0;
+	sdkp->device->use_16_for_sync = 1;
+
+	/* Check zoned block device characteristics (unconstrained reads) */
+	ret = sd_zbc_check_zoned_characteristics(sdkp, buf);
+	if (ret)
+		goto err;
+
+	/* Check the device capacity reported by report zones */
+	ret = sd_zbc_check_capacity(sdkp, buf, &zone_blocks);
+	if (ret != 0)
+		goto err;
+
+	nr_zones = round_up(sdkp->capacity, zone_blocks) >> ilog2(zone_blocks);
+	sdkp->early_zone_info.nr_zones = nr_zones;
+	sdkp->early_zone_info.zone_blocks = zone_blocks;
+
+	/* The drive satisfies the kernel restrictions: set it up */
+	if (sdkp->zones_max_open == U32_MAX)
+		lim->max_open_zones = 0;
+	else
+		lim->max_open_zones = sdkp->zones_max_open;
+	lim->max_active_zones = 0;
+	lim->chunk_sectors = logical_to_sectors(sdkp->device, zone_blocks);
+
+	return 0;
+
+err:
+	sdkp->capacity = 0;
+
+	return ret;
+}