xref: /linux/drivers/scsi/sd_zbc.c (revision 2c97b5ae83dca56718774e7b4bf9640f05d11867)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * SCSI Zoned Block commands
4  *
5  * Copyright (C) 2014-2015 SUSE Linux GmbH
6  * Written by: Hannes Reinecke <hare@suse.de>
7  * Modified by: Damien Le Moal <damien.lemoal@hgst.com>
8  * Modified by: Shaun Tancheff <shaun.tancheff@seagate.com>
9  */
10 
11 #include <linux/blkdev.h>
12 #include <linux/vmalloc.h>
13 #include <linux/sched/mm.h>
14 
15 #include <asm/unaligned.h>
16 
17 #include <scsi/scsi.h>
18 #include <scsi/scsi_cmnd.h>
19 
20 #include "sd.h"
21 
22 static int sd_zbc_parse_report(struct scsi_disk *sdkp, u8 *buf,
23 			       unsigned int idx, report_zones_cb cb, void *data)
24 {
25 	struct scsi_device *sdp = sdkp->device;
26 	struct blk_zone zone = { 0 };
27 
28 	zone.type = buf[0] & 0x0f;
29 	zone.cond = (buf[1] >> 4) & 0xf;
30 	if (buf[1] & 0x01)
31 		zone.reset = 1;
32 	if (buf[1] & 0x02)
33 		zone.non_seq = 1;
34 
35 	zone.len = logical_to_sectors(sdp, get_unaligned_be64(&buf[8]));
36 	zone.start = logical_to_sectors(sdp, get_unaligned_be64(&buf[16]));
37 	zone.wp = logical_to_sectors(sdp, get_unaligned_be64(&buf[24]));
38 	if (zone.type != ZBC_ZONE_TYPE_CONV &&
39 	    zone.cond == ZBC_ZONE_COND_FULL)
40 		zone.wp = zone.start + zone.len;
41 
42 	return cb(&zone, idx, data);
43 }
44 
45 /**
46  * sd_zbc_do_report_zones - Issue a REPORT ZONES scsi command.
47  * @sdkp: The target disk
48  * @buf: vmalloc-ed buffer to use for the reply
49  * @buflen: the buffer size
50  * @lba: Start LBA of the report
51  * @partial: Do partial report
52  *
53  * For internal use during device validation.
54  * Using partial=true can significantly speed up execution of a report zones
55  * command because the disk does not have to count all possible report matching
56  * zones and will only report the count of zones fitting in the command reply
57  * buffer.
58  */
59 static int sd_zbc_do_report_zones(struct scsi_disk *sdkp, unsigned char *buf,
60 				  unsigned int buflen, sector_t lba,
61 				  bool partial)
62 {
63 	struct scsi_device *sdp = sdkp->device;
64 	const int timeout = sdp->request_queue->rq_timeout;
65 	struct scsi_sense_hdr sshdr;
66 	unsigned char cmd[16];
67 	unsigned int rep_len;
68 	int result;
69 
70 	memset(cmd, 0, 16);
71 	cmd[0] = ZBC_IN;
72 	cmd[1] = ZI_REPORT_ZONES;
73 	put_unaligned_be64(lba, &cmd[2]);
74 	put_unaligned_be32(buflen, &cmd[10]);
75 	if (partial)
76 		cmd[14] = ZBC_REPORT_ZONE_PARTIAL;
77 
78 	result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
79 				  buf, buflen, &sshdr,
80 				  timeout, SD_MAX_RETRIES, NULL);
81 	if (result) {
82 		sd_printk(KERN_ERR, sdkp,
83 			  "REPORT ZONES lba %llu failed with %d/%d\n",
84 			  (unsigned long long)lba,
85 			  host_byte(result), driver_byte(result));
86 		return -EIO;
87 	}
88 
89 	rep_len = get_unaligned_be32(&buf[0]);
90 	if (rep_len < 64) {
91 		sd_printk(KERN_ERR, sdkp,
92 			  "REPORT ZONES report invalid length %u\n",
93 			  rep_len);
94 		return -EIO;
95 	}
96 
97 	return 0;
98 }
99 
100 /**
101  * Allocate a buffer for report zones reply.
102  * @sdkp: The target disk
103  * @nr_zones: Maximum number of zones to report
104  * @buflen: Size of the buffer allocated
105  *
106  * Try to allocate a reply buffer for the number of requested zones.
107  * The size of the buffer allocated may be smaller than requested to
108  * satify the device constraint (max_hw_sectors, max_segments, etc).
109  *
110  * Return the address of the allocated buffer and update @buflen with
111  * the size of the allocated buffer.
112  */
113 static void *sd_zbc_alloc_report_buffer(struct scsi_disk *sdkp,
114 					unsigned int nr_zones, size_t *buflen)
115 {
116 	struct request_queue *q = sdkp->disk->queue;
117 	size_t bufsize;
118 	void *buf;
119 
120 	/*
121 	 * Report zone buffer size should be at most 64B times the number of
122 	 * zones requested plus the 64B reply header, but should be at least
123 	 * SECTOR_SIZE for ATA devices.
124 	 * Make sure that this size does not exceed the hardware capabilities.
125 	 * Furthermore, since the report zone command cannot be split, make
126 	 * sure that the allocated buffer can always be mapped by limiting the
127 	 * number of pages allocated to the HBA max segments limit.
128 	 */
129 	nr_zones = min(nr_zones, sdkp->nr_zones);
130 	bufsize = roundup((nr_zones + 1) * 64, SECTOR_SIZE);
131 	bufsize = min_t(size_t, bufsize,
132 			queue_max_hw_sectors(q) << SECTOR_SHIFT);
133 	bufsize = min_t(size_t, bufsize, queue_max_segments(q) << PAGE_SHIFT);
134 
135 	while (bufsize >= SECTOR_SIZE) {
136 		buf = __vmalloc(bufsize,
137 				GFP_KERNEL | __GFP_ZERO | __GFP_NORETRY,
138 				PAGE_KERNEL);
139 		if (buf) {
140 			*buflen = bufsize;
141 			return buf;
142 		}
143 		bufsize >>= 1;
144 	}
145 
146 	return NULL;
147 }
148 
149 /**
150  * sd_zbc_zone_sectors - Get the device zone size in number of 512B sectors.
151  * @sdkp: The target disk
152  */
153 static inline sector_t sd_zbc_zone_sectors(struct scsi_disk *sdkp)
154 {
155 	return logical_to_sectors(sdkp->device, sdkp->zone_blocks);
156 }
157 
158 int sd_zbc_report_zones(struct gendisk *disk, sector_t sector,
159 			unsigned int nr_zones, report_zones_cb cb, void *data)
160 {
161 	struct scsi_disk *sdkp = scsi_disk(disk);
162 	unsigned int nr, i;
163 	unsigned char *buf;
164 	size_t offset, buflen = 0;
165 	int zone_idx = 0;
166 	int ret;
167 
168 	if (!sd_is_zoned(sdkp))
169 		/* Not a zoned device */
170 		return -EOPNOTSUPP;
171 
172 	buf = sd_zbc_alloc_report_buffer(sdkp, nr_zones, &buflen);
173 	if (!buf)
174 		return -ENOMEM;
175 
176 	while (zone_idx < nr_zones && sector < get_capacity(disk)) {
177 		ret = sd_zbc_do_report_zones(sdkp, buf, buflen,
178 				sectors_to_logical(sdkp->device, sector), true);
179 		if (ret)
180 			goto out;
181 
182 		offset = 0;
183 		nr = min(nr_zones, get_unaligned_be32(&buf[0]) / 64);
184 		if (!nr)
185 			break;
186 
187 		for (i = 0; i < nr && zone_idx < nr_zones; i++) {
188 			offset += 64;
189 			ret = sd_zbc_parse_report(sdkp, buf + offset, zone_idx,
190 						  cb, data);
191 			if (ret)
192 				goto out;
193 			zone_idx++;
194 		}
195 
196 		sector += sd_zbc_zone_sectors(sdkp) * i;
197 	}
198 
199 	ret = zone_idx;
200 out:
201 	kvfree(buf);
202 	return ret;
203 }
204 
205 /**
206  * sd_zbc_setup_zone_mgmt_cmnd - Prepare a zone ZBC_OUT command. The operations
207  *			can be RESET WRITE POINTER, OPEN, CLOSE or FINISH.
208  * @cmd: the command to setup
209  * @op: Operation to be performed
210  * @all: All zones control
211  *
212  * Called from sd_init_command() for REQ_OP_ZONE_RESET, REQ_OP_ZONE_RESET_ALL,
213  * REQ_OP_ZONE_OPEN, REQ_OP_ZONE_CLOSE or REQ_OP_ZONE_FINISH requests.
214  */
215 blk_status_t sd_zbc_setup_zone_mgmt_cmnd(struct scsi_cmnd *cmd,
216 					 unsigned char op, bool all)
217 {
218 	struct request *rq = cmd->request;
219 	struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
220 	sector_t sector = blk_rq_pos(rq);
221 	sector_t block = sectors_to_logical(sdkp->device, sector);
222 
223 	if (!sd_is_zoned(sdkp))
224 		/* Not a zoned device */
225 		return BLK_STS_IOERR;
226 
227 	if (sdkp->device->changed)
228 		return BLK_STS_IOERR;
229 
230 	if (sector & (sd_zbc_zone_sectors(sdkp) - 1))
231 		/* Unaligned request */
232 		return BLK_STS_IOERR;
233 
234 	cmd->cmd_len = 16;
235 	memset(cmd->cmnd, 0, cmd->cmd_len);
236 	cmd->cmnd[0] = ZBC_OUT;
237 	cmd->cmnd[1] = op;
238 	if (all)
239 		cmd->cmnd[14] = 0x1;
240 	else
241 		put_unaligned_be64(block, &cmd->cmnd[2]);
242 
243 	rq->timeout = SD_TIMEOUT;
244 	cmd->sc_data_direction = DMA_NONE;
245 	cmd->transfersize = 0;
246 	cmd->allowed = 0;
247 
248 	return BLK_STS_OK;
249 }
250 
251 /**
252  * sd_zbc_complete - ZBC command post processing.
253  * @cmd: Completed command
254  * @good_bytes: Command reply bytes
255  * @sshdr: command sense header
256  *
257  * Called from sd_done(). Process report zones reply and handle reset zone
258  * and write commands errors.
259  */
260 void sd_zbc_complete(struct scsi_cmnd *cmd, unsigned int good_bytes,
261 		     struct scsi_sense_hdr *sshdr)
262 {
263 	int result = cmd->result;
264 	struct request *rq = cmd->request;
265 
266 	if (op_is_zone_mgmt(req_op(rq)) &&
267 	    result &&
268 	    sshdr->sense_key == ILLEGAL_REQUEST &&
269 	    sshdr->asc == 0x24) {
270 		/*
271 		 * INVALID FIELD IN CDB error: a zone management command was
272 		 * attempted on a conventional zone. Nothing to worry about,
273 		 * so be quiet about the error.
274 		 */
275 		rq->rq_flags |= RQF_QUIET;
276 	}
277 }
278 
279 /**
280  * sd_zbc_check_zoned_characteristics - Check zoned block device characteristics
281  * @sdkp: Target disk
282  * @buf: Buffer where to store the VPD page data
283  *
284  * Read VPD page B6, get information and check that reads are unconstrained.
285  */
286 static int sd_zbc_check_zoned_characteristics(struct scsi_disk *sdkp,
287 					      unsigned char *buf)
288 {
289 
290 	if (scsi_get_vpd_page(sdkp->device, 0xb6, buf, 64)) {
291 		sd_printk(KERN_NOTICE, sdkp,
292 			  "Read zoned characteristics VPD page failed\n");
293 		return -ENODEV;
294 	}
295 
296 	if (sdkp->device->type != TYPE_ZBC) {
297 		/* Host-aware */
298 		sdkp->urswrz = 1;
299 		sdkp->zones_optimal_open = get_unaligned_be32(&buf[8]);
300 		sdkp->zones_optimal_nonseq = get_unaligned_be32(&buf[12]);
301 		sdkp->zones_max_open = 0;
302 	} else {
303 		/* Host-managed */
304 		sdkp->urswrz = buf[4] & 1;
305 		sdkp->zones_optimal_open = 0;
306 		sdkp->zones_optimal_nonseq = 0;
307 		sdkp->zones_max_open = get_unaligned_be32(&buf[16]);
308 	}
309 
310 	/*
311 	 * Check for unconstrained reads: host-managed devices with
312 	 * constrained reads (drives failing read after write pointer)
313 	 * are not supported.
314 	 */
315 	if (!sdkp->urswrz) {
316 		if (sdkp->first_scan)
317 			sd_printk(KERN_NOTICE, sdkp,
318 			  "constrained reads devices are not supported\n");
319 		return -ENODEV;
320 	}
321 
322 	return 0;
323 }
324 
325 /**
326  * sd_zbc_check_zones - Check the device capacity and zone sizes
327  * @sdkp: Target disk
328  *
329  * Check that the device capacity as reported by READ CAPACITY matches the
330  * max_lba value (plus one)of the report zones command reply. Also check that
331  * all zones of the device have an equal size, only allowing the last zone of
332  * the disk to have a smaller size (runt zone). The zone size must also be a
333  * power of two.
334  *
335  * Returns the zone size in number of blocks upon success or an error code
336  * upon failure.
337  */
338 static int sd_zbc_check_zones(struct scsi_disk *sdkp, unsigned char *buf,
339 			      u32 *zblocks)
340 {
341 	u64 zone_blocks = 0;
342 	sector_t max_lba;
343 	unsigned char *rec;
344 	int ret;
345 
346 	/* Do a report zone to get max_lba and the size of the first zone */
347 	ret = sd_zbc_do_report_zones(sdkp, buf, SD_BUF_SIZE, 0, false);
348 	if (ret)
349 		return ret;
350 
351 	if (sdkp->rc_basis == 0) {
352 		/* The max_lba field is the capacity of this device */
353 		max_lba = get_unaligned_be64(&buf[8]);
354 		if (sdkp->capacity != max_lba + 1) {
355 			if (sdkp->first_scan)
356 				sd_printk(KERN_WARNING, sdkp,
357 					"Changing capacity from %llu to max LBA+1 %llu\n",
358 					(unsigned long long)sdkp->capacity,
359 					(unsigned long long)max_lba + 1);
360 			sdkp->capacity = max_lba + 1;
361 		}
362 	}
363 
364 	/* Parse REPORT ZONES header */
365 	rec = buf + 64;
366 	zone_blocks = get_unaligned_be64(&rec[8]);
367 	if (!zone_blocks || !is_power_of_2(zone_blocks)) {
368 		if (sdkp->first_scan)
369 			sd_printk(KERN_NOTICE, sdkp,
370 				  "Devices with non power of 2 zone "
371 				  "size are not supported\n");
372 		return -ENODEV;
373 	}
374 
375 	if (logical_to_sectors(sdkp->device, zone_blocks) > UINT_MAX) {
376 		if (sdkp->first_scan)
377 			sd_printk(KERN_NOTICE, sdkp,
378 				  "Zone size too large\n");
379 		return -EFBIG;
380 	}
381 
382 	*zblocks = zone_blocks;
383 
384 	return 0;
385 }
386 
387 int sd_zbc_read_zones(struct scsi_disk *sdkp, unsigned char *buf)
388 {
389 	struct gendisk *disk = sdkp->disk;
390 	unsigned int nr_zones;
391 	u32 zone_blocks = 0;
392 	int ret;
393 
394 	if (!sd_is_zoned(sdkp))
395 		/*
396 		 * Device managed or normal SCSI disk,
397 		 * no special handling required
398 		 */
399 		return 0;
400 
401 	/* Check zoned block device characteristics (unconstrained reads) */
402 	ret = sd_zbc_check_zoned_characteristics(sdkp, buf);
403 	if (ret)
404 		goto err;
405 
406 	/*
407 	 * Check zone size: only devices with a constant zone size (except
408 	 * an eventual last runt zone) that is a power of 2 are supported.
409 	 */
410 	ret = sd_zbc_check_zones(sdkp, buf, &zone_blocks);
411 	if (ret != 0)
412 		goto err;
413 
414 	/* The drive satisfies the kernel restrictions: set it up */
415 	blk_queue_chunk_sectors(sdkp->disk->queue,
416 			logical_to_sectors(sdkp->device, zone_blocks));
417 	blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, sdkp->disk->queue);
418 	blk_queue_required_elevator_features(sdkp->disk->queue,
419 					     ELEVATOR_F_ZBD_SEQ_WRITE);
420 	nr_zones = round_up(sdkp->capacity, zone_blocks) >> ilog2(zone_blocks);
421 
422 	/* READ16/WRITE16 is mandatory for ZBC disks */
423 	sdkp->device->use_16_for_rw = 1;
424 	sdkp->device->use_10_for_rw = 0;
425 
426 	/*
427 	 * Revalidate the disk zone bitmaps once the block device capacity is
428 	 * set on the second revalidate execution during disk scan and if
429 	 * something changed when executing a normal revalidate.
430 	 */
431 	if (sdkp->first_scan) {
432 		sdkp->zone_blocks = zone_blocks;
433 		sdkp->nr_zones = nr_zones;
434 		return 0;
435 	}
436 
437 	if (sdkp->zone_blocks != zone_blocks ||
438 	    sdkp->nr_zones != nr_zones ||
439 	    disk->queue->nr_zones != nr_zones) {
440 		ret = blk_revalidate_disk_zones(disk);
441 		if (ret != 0)
442 			goto err;
443 		sdkp->zone_blocks = zone_blocks;
444 		sdkp->nr_zones = nr_zones;
445 	}
446 
447 	return 0;
448 
449 err:
450 	sdkp->capacity = 0;
451 
452 	return ret;
453 }
454 
455 void sd_zbc_print_zones(struct scsi_disk *sdkp)
456 {
457 	if (!sd_is_zoned(sdkp) || !sdkp->capacity)
458 		return;
459 
460 	if (sdkp->capacity & (sdkp->zone_blocks - 1))
461 		sd_printk(KERN_NOTICE, sdkp,
462 			  "%u zones of %u logical blocks + 1 runt zone\n",
463 			  sdkp->nr_zones - 1,
464 			  sdkp->zone_blocks);
465 	else
466 		sd_printk(KERN_NOTICE, sdkp,
467 			  "%u zones of %u logical blocks\n",
468 			  sdkp->nr_zones,
469 			  sdkp->zone_blocks);
470 }
471