xref: /openbmc/linux/drivers/scsi/sd_zbc.c (revision 88dca4ca)
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 start lba %llu failed\n", lba);
84 		sd_print_result(sdkp, "REPORT ZONES", result);
85 		if (driver_byte(result) == DRIVER_SENSE &&
86 		    scsi_sense_valid(&sshdr))
87 			sd_print_sense_hdr(sdkp, &sshdr);
88 		return -EIO;
89 	}
90 
91 	rep_len = get_unaligned_be32(&buf[0]);
92 	if (rep_len < 64) {
93 		sd_printk(KERN_ERR, sdkp,
94 			  "REPORT ZONES report invalid length %u\n",
95 			  rep_len);
96 		return -EIO;
97 	}
98 
99 	return 0;
100 }
101 
102 /**
103  * Allocate a buffer for report zones reply.
104  * @sdkp: The target disk
105  * @nr_zones: Maximum number of zones to report
106  * @buflen: Size of the buffer allocated
107  *
108  * Try to allocate a reply buffer for the number of requested zones.
109  * The size of the buffer allocated may be smaller than requested to
110  * satify the device constraint (max_hw_sectors, max_segments, etc).
111  *
112  * Return the address of the allocated buffer and update @buflen with
113  * the size of the allocated buffer.
114  */
115 static void *sd_zbc_alloc_report_buffer(struct scsi_disk *sdkp,
116 					unsigned int nr_zones, size_t *buflen)
117 {
118 	struct request_queue *q = sdkp->disk->queue;
119 	size_t bufsize;
120 	void *buf;
121 
122 	/*
123 	 * Report zone buffer size should be at most 64B times the number of
124 	 * zones requested plus the 64B reply header, but should be at least
125 	 * SECTOR_SIZE for ATA devices.
126 	 * Make sure that this size does not exceed the hardware capabilities.
127 	 * Furthermore, since the report zone command cannot be split, make
128 	 * sure that the allocated buffer can always be mapped by limiting the
129 	 * number of pages allocated to the HBA max segments limit.
130 	 */
131 	nr_zones = min(nr_zones, sdkp->nr_zones);
132 	bufsize = roundup((nr_zones + 1) * 64, SECTOR_SIZE);
133 	bufsize = min_t(size_t, bufsize,
134 			queue_max_hw_sectors(q) << SECTOR_SHIFT);
135 	bufsize = min_t(size_t, bufsize, queue_max_segments(q) << PAGE_SHIFT);
136 
137 	while (bufsize >= SECTOR_SIZE) {
138 		buf = __vmalloc(bufsize,
139 				GFP_KERNEL | __GFP_ZERO | __GFP_NORETRY);
140 		if (buf) {
141 			*buflen = bufsize;
142 			return buf;
143 		}
144 		bufsize >>= 1;
145 	}
146 
147 	return NULL;
148 }
149 
150 /**
151  * sd_zbc_zone_sectors - Get the device zone size in number of 512B sectors.
152  * @sdkp: The target disk
153  */
154 static inline sector_t sd_zbc_zone_sectors(struct scsi_disk *sdkp)
155 {
156 	return logical_to_sectors(sdkp->device, sdkp->zone_blocks);
157 }
158 
159 int sd_zbc_report_zones(struct gendisk *disk, sector_t sector,
160 			unsigned int nr_zones, report_zones_cb cb, void *data)
161 {
162 	struct scsi_disk *sdkp = scsi_disk(disk);
163 	sector_t capacity = logical_to_sectors(sdkp->device, sdkp->capacity);
164 	unsigned int nr, i;
165 	unsigned char *buf;
166 	size_t offset, buflen = 0;
167 	int zone_idx = 0;
168 	int ret;
169 
170 	if (!sd_is_zoned(sdkp))
171 		/* Not a zoned device */
172 		return -EOPNOTSUPP;
173 
174 	if (!capacity)
175 		/* Device gone or invalid */
176 		return -ENODEV;
177 
178 	buf = sd_zbc_alloc_report_buffer(sdkp, nr_zones, &buflen);
179 	if (!buf)
180 		return -ENOMEM;
181 
182 	while (zone_idx < nr_zones && sector < capacity) {
183 		ret = sd_zbc_do_report_zones(sdkp, buf, buflen,
184 				sectors_to_logical(sdkp->device, sector), true);
185 		if (ret)
186 			goto out;
187 
188 		offset = 0;
189 		nr = min(nr_zones, get_unaligned_be32(&buf[0]) / 64);
190 		if (!nr)
191 			break;
192 
193 		for (i = 0; i < nr && zone_idx < nr_zones; i++) {
194 			offset += 64;
195 			ret = sd_zbc_parse_report(sdkp, buf + offset, zone_idx,
196 						  cb, data);
197 			if (ret)
198 				goto out;
199 			zone_idx++;
200 		}
201 
202 		sector += sd_zbc_zone_sectors(sdkp) * i;
203 	}
204 
205 	ret = zone_idx;
206 out:
207 	kvfree(buf);
208 	return ret;
209 }
210 
211 /**
212  * sd_zbc_setup_zone_mgmt_cmnd - Prepare a zone ZBC_OUT command. The operations
213  *			can be RESET WRITE POINTER, OPEN, CLOSE or FINISH.
214  * @cmd: the command to setup
215  * @op: Operation to be performed
216  * @all: All zones control
217  *
218  * Called from sd_init_command() for REQ_OP_ZONE_RESET, REQ_OP_ZONE_RESET_ALL,
219  * REQ_OP_ZONE_OPEN, REQ_OP_ZONE_CLOSE or REQ_OP_ZONE_FINISH requests.
220  */
221 blk_status_t sd_zbc_setup_zone_mgmt_cmnd(struct scsi_cmnd *cmd,
222 					 unsigned char op, bool all)
223 {
224 	struct request *rq = cmd->request;
225 	struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
226 	sector_t sector = blk_rq_pos(rq);
227 	sector_t block = sectors_to_logical(sdkp->device, sector);
228 
229 	if (!sd_is_zoned(sdkp))
230 		/* Not a zoned device */
231 		return BLK_STS_IOERR;
232 
233 	if (sdkp->device->changed)
234 		return BLK_STS_IOERR;
235 
236 	if (sector & (sd_zbc_zone_sectors(sdkp) - 1))
237 		/* Unaligned request */
238 		return BLK_STS_IOERR;
239 
240 	cmd->cmd_len = 16;
241 	memset(cmd->cmnd, 0, cmd->cmd_len);
242 	cmd->cmnd[0] = ZBC_OUT;
243 	cmd->cmnd[1] = op;
244 	if (all)
245 		cmd->cmnd[14] = 0x1;
246 	else
247 		put_unaligned_be64(block, &cmd->cmnd[2]);
248 
249 	rq->timeout = SD_TIMEOUT;
250 	cmd->sc_data_direction = DMA_NONE;
251 	cmd->transfersize = 0;
252 	cmd->allowed = 0;
253 
254 	return BLK_STS_OK;
255 }
256 
257 /**
258  * sd_zbc_complete - ZBC command post processing.
259  * @cmd: Completed command
260  * @good_bytes: Command reply bytes
261  * @sshdr: command sense header
262  *
263  * Called from sd_done(). Process report zones reply and handle reset zone
264  * and write commands errors.
265  */
266 void sd_zbc_complete(struct scsi_cmnd *cmd, unsigned int good_bytes,
267 		     struct scsi_sense_hdr *sshdr)
268 {
269 	int result = cmd->result;
270 	struct request *rq = cmd->request;
271 
272 	if (op_is_zone_mgmt(req_op(rq)) &&
273 	    result &&
274 	    sshdr->sense_key == ILLEGAL_REQUEST &&
275 	    sshdr->asc == 0x24) {
276 		/*
277 		 * INVALID FIELD IN CDB error: a zone management command was
278 		 * attempted on a conventional zone. Nothing to worry about,
279 		 * so be quiet about the error.
280 		 */
281 		rq->rq_flags |= RQF_QUIET;
282 	}
283 }
284 
285 /**
286  * sd_zbc_check_zoned_characteristics - Check zoned block device characteristics
287  * @sdkp: Target disk
288  * @buf: Buffer where to store the VPD page data
289  *
290  * Read VPD page B6, get information and check that reads are unconstrained.
291  */
292 static int sd_zbc_check_zoned_characteristics(struct scsi_disk *sdkp,
293 					      unsigned char *buf)
294 {
295 
296 	if (scsi_get_vpd_page(sdkp->device, 0xb6, buf, 64)) {
297 		sd_printk(KERN_NOTICE, sdkp,
298 			  "Read zoned characteristics VPD page failed\n");
299 		return -ENODEV;
300 	}
301 
302 	if (sdkp->device->type != TYPE_ZBC) {
303 		/* Host-aware */
304 		sdkp->urswrz = 1;
305 		sdkp->zones_optimal_open = get_unaligned_be32(&buf[8]);
306 		sdkp->zones_optimal_nonseq = get_unaligned_be32(&buf[12]);
307 		sdkp->zones_max_open = 0;
308 	} else {
309 		/* Host-managed */
310 		sdkp->urswrz = buf[4] & 1;
311 		sdkp->zones_optimal_open = 0;
312 		sdkp->zones_optimal_nonseq = 0;
313 		sdkp->zones_max_open = get_unaligned_be32(&buf[16]);
314 	}
315 
316 	/*
317 	 * Check for unconstrained reads: host-managed devices with
318 	 * constrained reads (drives failing read after write pointer)
319 	 * are not supported.
320 	 */
321 	if (!sdkp->urswrz) {
322 		if (sdkp->first_scan)
323 			sd_printk(KERN_NOTICE, sdkp,
324 			  "constrained reads devices are not supported\n");
325 		return -ENODEV;
326 	}
327 
328 	return 0;
329 }
330 
331 /**
332  * sd_zbc_check_capacity - Check the device capacity
333  * @sdkp: Target disk
334  * @buf: command buffer
335  * @zblock: zone size in number of blocks
336  *
337  * Get the device zone size and check that the device capacity as reported
338  * by READ CAPACITY matches the max_lba value (plus one) of the report zones
339  * command reply for devices with RC_BASIS == 0.
340  *
341  * Returns 0 upon success or an error code upon failure.
342  */
343 static int sd_zbc_check_capacity(struct scsi_disk *sdkp, unsigned char *buf,
344 				 u32 *zblocks)
345 {
346 	u64 zone_blocks;
347 	sector_t max_lba;
348 	unsigned char *rec;
349 	int ret;
350 
351 	/* Do a report zone to get max_lba and the size of the first zone */
352 	ret = sd_zbc_do_report_zones(sdkp, buf, SD_BUF_SIZE, 0, false);
353 	if (ret)
354 		return ret;
355 
356 	if (sdkp->rc_basis == 0) {
357 		/* The max_lba field is the capacity of this device */
358 		max_lba = get_unaligned_be64(&buf[8]);
359 		if (sdkp->capacity != max_lba + 1) {
360 			if (sdkp->first_scan)
361 				sd_printk(KERN_WARNING, sdkp,
362 					"Changing capacity from %llu to max LBA+1 %llu\n",
363 					(unsigned long long)sdkp->capacity,
364 					(unsigned long long)max_lba + 1);
365 			sdkp->capacity = max_lba + 1;
366 		}
367 	}
368 
369 	/* Get the size of the first reported zone */
370 	rec = buf + 64;
371 	zone_blocks = get_unaligned_be64(&rec[8]);
372 	if (logical_to_sectors(sdkp->device, zone_blocks) > UINT_MAX) {
373 		if (sdkp->first_scan)
374 			sd_printk(KERN_NOTICE, sdkp,
375 				  "Zone size too large\n");
376 		return -EFBIG;
377 	}
378 
379 	*zblocks = zone_blocks;
380 
381 	return 0;
382 }
383 
384 int sd_zbc_read_zones(struct scsi_disk *sdkp, unsigned char *buf)
385 {
386 	struct gendisk *disk = sdkp->disk;
387 	unsigned int nr_zones;
388 	u32 zone_blocks = 0;
389 	int ret;
390 
391 	if (!sd_is_zoned(sdkp))
392 		/*
393 		 * Device managed or normal SCSI disk,
394 		 * no special handling required
395 		 */
396 		return 0;
397 
398 	/* Check zoned block device characteristics (unconstrained reads) */
399 	ret = sd_zbc_check_zoned_characteristics(sdkp, buf);
400 	if (ret)
401 		goto err;
402 
403 	/* Check the device capacity reported by report zones */
404 	ret = sd_zbc_check_capacity(sdkp, buf, &zone_blocks);
405 	if (ret != 0)
406 		goto err;
407 
408 	/* The drive satisfies the kernel restrictions: set it up */
409 	blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, sdkp->disk->queue);
410 	blk_queue_required_elevator_features(sdkp->disk->queue,
411 					     ELEVATOR_F_ZBD_SEQ_WRITE);
412 	nr_zones = round_up(sdkp->capacity, zone_blocks) >> ilog2(zone_blocks);
413 
414 	/* READ16/WRITE16 is mandatory for ZBC disks */
415 	sdkp->device->use_16_for_rw = 1;
416 	sdkp->device->use_10_for_rw = 0;
417 
418 	/*
419 	 * Revalidate the disk zone bitmaps once the block device capacity is
420 	 * set on the second revalidate execution during disk scan and if
421 	 * something changed when executing a normal revalidate.
422 	 */
423 	if (sdkp->first_scan) {
424 		sdkp->zone_blocks = zone_blocks;
425 		sdkp->nr_zones = nr_zones;
426 		return 0;
427 	}
428 
429 	if (sdkp->zone_blocks != zone_blocks ||
430 	    sdkp->nr_zones != nr_zones ||
431 	    disk->queue->nr_zones != nr_zones) {
432 		ret = blk_revalidate_disk_zones(disk);
433 		if (ret != 0)
434 			goto err;
435 		sdkp->zone_blocks = zone_blocks;
436 		sdkp->nr_zones = nr_zones;
437 	}
438 
439 	return 0;
440 
441 err:
442 	sdkp->capacity = 0;
443 
444 	return ret;
445 }
446 
447 void sd_zbc_print_zones(struct scsi_disk *sdkp)
448 {
449 	if (!sd_is_zoned(sdkp) || !sdkp->capacity)
450 		return;
451 
452 	if (sdkp->capacity & (sdkp->zone_blocks - 1))
453 		sd_printk(KERN_NOTICE, sdkp,
454 			  "%u zones of %u logical blocks + 1 runt zone\n",
455 			  sdkp->nr_zones - 1,
456 			  sdkp->zone_blocks);
457 	else
458 		sd_printk(KERN_NOTICE, sdkp,
459 			  "%u zones of %u logical blocks\n",
460 			  sdkp->nr_zones,
461 			  sdkp->zone_blocks);
462 }
463