summaryrefslogtreecommitdiff
path: root/drivers/scsi/sd_zbc.c
blob: e4282bce583475a046a679093d4ddf6cc706b105 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
// 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 <asm/unaligned.h>

#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>

#include "sd.h"

static int sd_zbc_parse_report(struct scsi_disk *sdkp, u8 *buf,
			       unsigned int idx, report_zones_cb cb, void *data)
{
	struct scsi_device *sdp = sdkp->device;
	struct blk_zone zone = { 0 };

	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;

	return cb(&zone, idx, data);
}

/**
 * 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;
	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_req(sdp, cmd, DMA_FROM_DEVICE,
				  buf, buflen, &sshdr,
				  timeout, SD_MAX_RETRIES, NULL);
	if (result) {
		sd_printk(KERN_ERR, sdkp,
			  "REPORT ZONES start lba %llu failed\n", lba);
		sd_print_result(sdkp, "REPORT ZONES", result);
		if (driver_byte(result) == DRIVER_SENSE &&
		    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;
}

/**
 * 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;
	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 at least
	 * 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.
	 */
	nr_zones = min(nr_zones, sdkp->nr_zones);
	bufsize = roundup((nr_zones + 1) * 64, SECTOR_SIZE);
	bufsize = min_t(size_t, bufsize,
			queue_max_hw_sectors(q) << SECTOR_SHIFT);
	bufsize = min_t(size_t, bufsize, queue_max_segments(q) << PAGE_SHIFT);

	while (bufsize >= SECTOR_SIZE) {
		buf = __vmalloc(bufsize,
				GFP_KERNEL | __GFP_ZERO | __GFP_NORETRY,
				PAGE_KERNEL);
		if (buf) {
			*buflen = bufsize;
			return buf;
		}
		bufsize >>= 1;
	}

	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_blocks);
}

int sd_zbc_report_zones(struct gendisk *disk, sector_t sector,
			unsigned int nr_zones, report_zones_cb cb, void *data)
{
	struct scsi_disk *sdkp = scsi_disk(disk);
	unsigned int nr, i;
	unsigned char *buf;
	size_t offset, buflen = 0;
	int zone_idx = 0;
	int ret;

	if (!sd_is_zoned(sdkp))
		/* Not a zoned device */
		return -EOPNOTSUPP;

	buf = sd_zbc_alloc_report_buffer(sdkp, nr_zones, &buflen);
	if (!buf)
		return -ENOMEM;

	while (zone_idx < nr_zones && sector < get_capacity(disk)) {
		ret = sd_zbc_do_report_zones(sdkp, buf, buflen,
				sectors_to_logical(sdkp->device, sector), 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;
			ret = sd_zbc_parse_report(sdkp, buf + offset, zone_idx,
						  cb, data);
			if (ret)
				goto out;
			zone_idx++;
		}

		sector += sd_zbc_zone_sectors(sdkp) * i;
	}

	ret = zone_idx;
out:
	kvfree(buf);
	return ret;
}

/**
 * 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 = 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] = 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(). 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;

	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;
	}
}

/**
 * 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;
}

/**
 * sd_zbc_check_capacity - Check the device capacity
 * @sdkp: Target disk
 * @buf: command buffer
 * @zblock: zone size in number of 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;
		}
	}

	/* 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;
	}

	*zblocks = zone_blocks;

	return 0;
}

int sd_zbc_read_zones(struct scsi_disk *sdkp, unsigned char *buf)
{
	struct gendisk *disk = sdkp->disk;
	unsigned int nr_zones;
	u32 zone_blocks = 0;
	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 the device capacity reported by report zones */
	ret = sd_zbc_check_capacity(sdkp, buf, &zone_blocks);
	if (ret != 0)
		goto err;

	/* The drive satisfies the kernel restrictions: set it up */
	blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, sdkp->disk->queue);
	blk_queue_required_elevator_features(sdkp->disk->queue,
					     ELEVATOR_F_ZBD_SEQ_WRITE);
	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);
}