block: remove i_bdev
[linux-2.6-microblaze.git] / drivers / target / target_core_sbc.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * SCSI Block Commands (SBC) parsing and emulation.
4  *
5  * (c) Copyright 2002-2013 Datera, Inc.
6  *
7  * Nicholas A. Bellinger <nab@kernel.org>
8  */
9
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/ratelimit.h>
13 #include <linux/crc-t10dif.h>
14 #include <linux/t10-pi.h>
15 #include <asm/unaligned.h>
16 #include <scsi/scsi_proto.h>
17 #include <scsi/scsi_tcq.h>
18
19 #include <target/target_core_base.h>
20 #include <target/target_core_backend.h>
21 #include <target/target_core_fabric.h>
22
23 #include "target_core_internal.h"
24 #include "target_core_ua.h"
25 #include "target_core_alua.h"
26
27 static sense_reason_t
28 sbc_check_prot(struct se_device *, struct se_cmd *, unsigned char *, u32, bool);
29 static sense_reason_t sbc_execute_unmap(struct se_cmd *cmd);
30
31 static sense_reason_t
32 sbc_emulate_readcapacity(struct se_cmd *cmd)
33 {
34         struct se_device *dev = cmd->se_dev;
35         unsigned char *cdb = cmd->t_task_cdb;
36         unsigned long long blocks_long = dev->transport->get_blocks(dev);
37         unsigned char *rbuf;
38         unsigned char buf[8];
39         u32 blocks;
40
41         /*
42          * SBC-2 says:
43          *   If the PMI bit is set to zero and the LOGICAL BLOCK
44          *   ADDRESS field is not set to zero, the device server shall
45          *   terminate the command with CHECK CONDITION status with
46          *   the sense key set to ILLEGAL REQUEST and the additional
47          *   sense code set to INVALID FIELD IN CDB.
48          *
49          * In SBC-3, these fields are obsolete, but some SCSI
50          * compliance tests actually check this, so we might as well
51          * follow SBC-2.
52          */
53         if (!(cdb[8] & 1) && !!(cdb[2] | cdb[3] | cdb[4] | cdb[5]))
54                 return TCM_INVALID_CDB_FIELD;
55
56         if (blocks_long >= 0x00000000ffffffff)
57                 blocks = 0xffffffff;
58         else
59                 blocks = (u32)blocks_long;
60
61         put_unaligned_be32(blocks, &buf[0]);
62         put_unaligned_be32(dev->dev_attrib.block_size, &buf[4]);
63
64         rbuf = transport_kmap_data_sg(cmd);
65         if (rbuf) {
66                 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
67                 transport_kunmap_data_sg(cmd);
68         }
69
70         target_complete_cmd_with_length(cmd, GOOD, 8);
71         return 0;
72 }
73
74 static sense_reason_t
75 sbc_emulate_readcapacity_16(struct se_cmd *cmd)
76 {
77         struct se_device *dev = cmd->se_dev;
78         struct se_session *sess = cmd->se_sess;
79         int pi_prot_type = dev->dev_attrib.pi_prot_type;
80
81         unsigned char *rbuf;
82         unsigned char buf[32];
83         unsigned long long blocks = dev->transport->get_blocks(dev);
84
85         memset(buf, 0, sizeof(buf));
86         put_unaligned_be64(blocks, &buf[0]);
87         put_unaligned_be32(dev->dev_attrib.block_size, &buf[8]);
88         /*
89          * Set P_TYPE and PROT_EN bits for DIF support
90          */
91         if (sess->sup_prot_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS)) {
92                 /*
93                  * Only override a device's pi_prot_type if no T10-PI is
94                  * available, and sess_prot_type has been explicitly enabled.
95                  */
96                 if (!pi_prot_type)
97                         pi_prot_type = sess->sess_prot_type;
98
99                 if (pi_prot_type)
100                         buf[12] = (pi_prot_type - 1) << 1 | 0x1;
101         }
102
103         if (dev->transport->get_lbppbe)
104                 buf[13] = dev->transport->get_lbppbe(dev) & 0x0f;
105
106         if (dev->transport->get_alignment_offset_lbas) {
107                 u16 lalba = dev->transport->get_alignment_offset_lbas(dev);
108
109                 put_unaligned_be16(lalba, &buf[14]);
110         }
111
112         /*
113          * Set Thin Provisioning Enable bit following sbc3r22 in section
114          * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
115          */
116         if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws) {
117                 buf[14] |= 0x80;
118
119                 /*
120                  * LBPRZ signifies that zeroes will be read back from an LBA after
121                  * an UNMAP or WRITE SAME w/ unmap bit (sbc3r36 5.16.2)
122                  */
123                 if (dev->dev_attrib.unmap_zeroes_data)
124                         buf[14] |= 0x40;
125         }
126
127         rbuf = transport_kmap_data_sg(cmd);
128         if (rbuf) {
129                 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
130                 transport_kunmap_data_sg(cmd);
131         }
132
133         target_complete_cmd_with_length(cmd, GOOD, 32);
134         return 0;
135 }
136
137 static sense_reason_t
138 sbc_emulate_startstop(struct se_cmd *cmd)
139 {
140         unsigned char *cdb = cmd->t_task_cdb;
141
142         /*
143          * See sbc3r36 section 5.25
144          * Immediate bit should be set since there is nothing to complete
145          * POWER CONDITION MODIFIER 0h
146          */
147         if (!(cdb[1] & 1) || cdb[2] || cdb[3])
148                 return TCM_INVALID_CDB_FIELD;
149
150         /*
151          * See sbc3r36 section 5.25
152          * POWER CONDITION 0h START_VALID - process START and LOEJ
153          */
154         if (cdb[4] >> 4 & 0xf)
155                 return TCM_INVALID_CDB_FIELD;
156
157         /*
158          * See sbc3r36 section 5.25
159          * LOEJ 0h - nothing to load or unload
160          * START 1h - we are ready
161          */
162         if (!(cdb[4] & 1) || (cdb[4] & 2) || (cdb[4] & 4))
163                 return TCM_INVALID_CDB_FIELD;
164
165         target_complete_cmd(cmd, SAM_STAT_GOOD);
166         return 0;
167 }
168
169 sector_t sbc_get_write_same_sectors(struct se_cmd *cmd)
170 {
171         u32 num_blocks;
172
173         if (cmd->t_task_cdb[0] == WRITE_SAME)
174                 num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]);
175         else if (cmd->t_task_cdb[0] == WRITE_SAME_16)
176                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]);
177         else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
178                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]);
179
180         /*
181          * Use the explicit range when non zero is supplied, otherwise calculate
182          * the remaining range based on ->get_blocks() - starting LBA.
183          */
184         if (num_blocks)
185                 return num_blocks;
186
187         return cmd->se_dev->transport->get_blocks(cmd->se_dev) -
188                 cmd->t_task_lba + 1;
189 }
190 EXPORT_SYMBOL(sbc_get_write_same_sectors);
191
192 static sense_reason_t
193 sbc_execute_write_same_unmap(struct se_cmd *cmd)
194 {
195         struct sbc_ops *ops = cmd->protocol_data;
196         sector_t nolb = sbc_get_write_same_sectors(cmd);
197         sense_reason_t ret;
198
199         if (nolb) {
200                 ret = ops->execute_unmap(cmd, cmd->t_task_lba, nolb);
201                 if (ret)
202                         return ret;
203         }
204
205         target_complete_cmd(cmd, GOOD);
206         return 0;
207 }
208
209 static sense_reason_t
210 sbc_emulate_noop(struct se_cmd *cmd)
211 {
212         target_complete_cmd(cmd, GOOD);
213         return 0;
214 }
215
216 static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
217 {
218         return cmd->se_dev->dev_attrib.block_size * sectors;
219 }
220
221 static inline u32 transport_get_sectors_6(unsigned char *cdb)
222 {
223         /*
224          * Use 8-bit sector value.  SBC-3 says:
225          *
226          *   A TRANSFER LENGTH field set to zero specifies that 256
227          *   logical blocks shall be written.  Any other value
228          *   specifies the number of logical blocks that shall be
229          *   written.
230          */
231         return cdb[4] ? : 256;
232 }
233
234 static inline u32 transport_get_sectors_10(unsigned char *cdb)
235 {
236         return get_unaligned_be16(&cdb[7]);
237 }
238
239 static inline u32 transport_get_sectors_12(unsigned char *cdb)
240 {
241         return get_unaligned_be32(&cdb[6]);
242 }
243
244 static inline u32 transport_get_sectors_16(unsigned char *cdb)
245 {
246         return get_unaligned_be32(&cdb[10]);
247 }
248
249 /*
250  * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
251  */
252 static inline u32 transport_get_sectors_32(unsigned char *cdb)
253 {
254         return get_unaligned_be32(&cdb[28]);
255
256 }
257
258 static inline u32 transport_lba_21(unsigned char *cdb)
259 {
260         return get_unaligned_be24(&cdb[1]) & 0x1fffff;
261 }
262
263 static inline u32 transport_lba_32(unsigned char *cdb)
264 {
265         return get_unaligned_be32(&cdb[2]);
266 }
267
268 static inline unsigned long long transport_lba_64(unsigned char *cdb)
269 {
270         return get_unaligned_be64(&cdb[2]);
271 }
272
273 /*
274  * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
275  */
276 static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
277 {
278         return get_unaligned_be64(&cdb[12]);
279 }
280
281 static sense_reason_t
282 sbc_setup_write_same(struct se_cmd *cmd, unsigned char *flags, struct sbc_ops *ops)
283 {
284         struct se_device *dev = cmd->se_dev;
285         sector_t end_lba = dev->transport->get_blocks(dev) + 1;
286         unsigned int sectors = sbc_get_write_same_sectors(cmd);
287         sense_reason_t ret;
288
289         if ((flags[0] & 0x04) || (flags[0] & 0x02)) {
290                 pr_err("WRITE_SAME PBDATA and LBDATA"
291                         " bits not supported for Block Discard"
292                         " Emulation\n");
293                 return TCM_UNSUPPORTED_SCSI_OPCODE;
294         }
295         if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
296                 pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
297                         sectors, cmd->se_dev->dev_attrib.max_write_same_len);
298                 return TCM_INVALID_CDB_FIELD;
299         }
300         /*
301          * Sanity check for LBA wrap and request past end of device.
302          */
303         if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
304             ((cmd->t_task_lba + sectors) > end_lba)) {
305                 pr_err("WRITE_SAME exceeds last lba %llu (lba %llu, sectors %u)\n",
306                        (unsigned long long)end_lba, cmd->t_task_lba, sectors);
307                 return TCM_ADDRESS_OUT_OF_RANGE;
308         }
309
310         /* We always have ANC_SUP == 0 so setting ANCHOR is always an error */
311         if (flags[0] & 0x10) {
312                 pr_warn("WRITE SAME with ANCHOR not supported\n");
313                 return TCM_INVALID_CDB_FIELD;
314         }
315         /*
316          * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
317          * translated into block discard requests within backend code.
318          */
319         if (flags[0] & 0x08) {
320                 if (!ops->execute_unmap)
321                         return TCM_UNSUPPORTED_SCSI_OPCODE;
322
323                 if (!dev->dev_attrib.emulate_tpws) {
324                         pr_err("Got WRITE_SAME w/ UNMAP=1, but backend device"
325                                " has emulate_tpws disabled\n");
326                         return TCM_UNSUPPORTED_SCSI_OPCODE;
327                 }
328                 cmd->execute_cmd = sbc_execute_write_same_unmap;
329                 return 0;
330         }
331         if (!ops->execute_write_same)
332                 return TCM_UNSUPPORTED_SCSI_OPCODE;
333
334         ret = sbc_check_prot(dev, cmd, &cmd->t_task_cdb[0], sectors, true);
335         if (ret)
336                 return ret;
337
338         cmd->execute_cmd = ops->execute_write_same;
339         return 0;
340 }
341
342 static sense_reason_t xdreadwrite_callback(struct se_cmd *cmd, bool success,
343                                            int *post_ret)
344 {
345         unsigned char *buf, *addr;
346         struct scatterlist *sg;
347         unsigned int offset;
348         sense_reason_t ret = TCM_NO_SENSE;
349         int i, count;
350
351         if (!success)
352                 return 0;
353
354         /*
355          * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
356          *
357          * 1) read the specified logical block(s);
358          * 2) transfer logical blocks from the data-out buffer;
359          * 3) XOR the logical blocks transferred from the data-out buffer with
360          *    the logical blocks read, storing the resulting XOR data in a buffer;
361          * 4) if the DISABLE WRITE bit is set to zero, then write the logical
362          *    blocks transferred from the data-out buffer; and
363          * 5) transfer the resulting XOR data to the data-in buffer.
364          */
365         buf = kmalloc(cmd->data_length, GFP_KERNEL);
366         if (!buf) {
367                 pr_err("Unable to allocate xor_callback buf\n");
368                 return TCM_OUT_OF_RESOURCES;
369         }
370         /*
371          * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
372          * into the locally allocated *buf
373          */
374         sg_copy_to_buffer(cmd->t_data_sg,
375                           cmd->t_data_nents,
376                           buf,
377                           cmd->data_length);
378
379         /*
380          * Now perform the XOR against the BIDI read memory located at
381          * cmd->t_mem_bidi_list
382          */
383
384         offset = 0;
385         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
386                 addr = kmap_atomic(sg_page(sg));
387                 if (!addr) {
388                         ret = TCM_OUT_OF_RESOURCES;
389                         goto out;
390                 }
391
392                 for (i = 0; i < sg->length; i++)
393                         *(addr + sg->offset + i) ^= *(buf + offset + i);
394
395                 offset += sg->length;
396                 kunmap_atomic(addr);
397         }
398
399 out:
400         kfree(buf);
401         return ret;
402 }
403
404 static sense_reason_t
405 sbc_execute_rw(struct se_cmd *cmd)
406 {
407         struct sbc_ops *ops = cmd->protocol_data;
408
409         return ops->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
410                                cmd->data_direction);
411 }
412
413 static sense_reason_t compare_and_write_post(struct se_cmd *cmd, bool success,
414                                              int *post_ret)
415 {
416         struct se_device *dev = cmd->se_dev;
417         sense_reason_t ret = TCM_NO_SENSE;
418
419         spin_lock_irq(&cmd->t_state_lock);
420         if (success) {
421                 *post_ret = 1;
422
423                 if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
424                         ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
425         }
426         spin_unlock_irq(&cmd->t_state_lock);
427
428         /*
429          * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
430          * before the original READ I/O submission.
431          */
432         up(&dev->caw_sem);
433
434         return ret;
435 }
436
437 static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool success,
438                                                  int *post_ret)
439 {
440         struct se_device *dev = cmd->se_dev;
441         struct sg_table write_tbl = { };
442         struct scatterlist *write_sg, *sg;
443         unsigned char *buf = NULL, *addr;
444         struct sg_mapping_iter m;
445         unsigned int offset = 0, len;
446         unsigned int nlbas = cmd->t_task_nolb;
447         unsigned int block_size = dev->dev_attrib.block_size;
448         unsigned int compare_len = (nlbas * block_size);
449         sense_reason_t ret = TCM_NO_SENSE;
450         int rc, i;
451
452         /*
453          * Handle early failure in transport_generic_request_failure(),
454          * which will not have taken ->caw_sem yet..
455          */
456         if (!success && (!cmd->t_data_sg || !cmd->t_bidi_data_sg))
457                 return TCM_NO_SENSE;
458         /*
459          * Handle special case for zero-length COMPARE_AND_WRITE
460          */
461         if (!cmd->data_length)
462                 goto out;
463         /*
464          * Immediately exit + release dev->caw_sem if command has already
465          * been failed with a non-zero SCSI status.
466          */
467         if (cmd->scsi_status) {
468                 pr_debug("compare_and_write_callback: non zero scsi_status:"
469                         " 0x%02x\n", cmd->scsi_status);
470                 *post_ret = 1;
471                 if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
472                         ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
473                 goto out;
474         }
475
476         buf = kzalloc(cmd->data_length, GFP_KERNEL);
477         if (!buf) {
478                 pr_err("Unable to allocate compare_and_write buf\n");
479                 ret = TCM_OUT_OF_RESOURCES;
480                 goto out;
481         }
482
483         if (sg_alloc_table(&write_tbl, cmd->t_data_nents, GFP_KERNEL) < 0) {
484                 pr_err("Unable to allocate compare_and_write sg\n");
485                 ret = TCM_OUT_OF_RESOURCES;
486                 goto out;
487         }
488         write_sg = write_tbl.sgl;
489         /*
490          * Setup verify and write data payloads from total NumberLBAs.
491          */
492         rc = sg_copy_to_buffer(cmd->t_data_sg, cmd->t_data_nents, buf,
493                                cmd->data_length);
494         if (!rc) {
495                 pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
496                 ret = TCM_OUT_OF_RESOURCES;
497                 goto out;
498         }
499         /*
500          * Compare against SCSI READ payload against verify payload
501          */
502         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, i) {
503                 addr = (unsigned char *)kmap_atomic(sg_page(sg));
504                 if (!addr) {
505                         ret = TCM_OUT_OF_RESOURCES;
506                         goto out;
507                 }
508
509                 len = min(sg->length, compare_len);
510
511                 if (memcmp(addr, buf + offset, len)) {
512                         pr_warn("Detected MISCOMPARE for addr: %p buf: %p\n",
513                                 addr, buf + offset);
514                         kunmap_atomic(addr);
515                         goto miscompare;
516                 }
517                 kunmap_atomic(addr);
518
519                 offset += len;
520                 compare_len -= len;
521                 if (!compare_len)
522                         break;
523         }
524
525         i = 0;
526         len = cmd->t_task_nolb * block_size;
527         sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
528         /*
529          * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
530          */
531         while (len) {
532                 sg_miter_next(&m);
533
534                 if (block_size < PAGE_SIZE) {
535                         sg_set_page(&write_sg[i], m.page, block_size,
536                                     m.piter.sg->offset + block_size);
537                 } else {
538                         sg_miter_next(&m);
539                         sg_set_page(&write_sg[i], m.page, block_size,
540                                     m.piter.sg->offset);
541                 }
542                 len -= block_size;
543                 i++;
544         }
545         sg_miter_stop(&m);
546         /*
547          * Save the original SGL + nents values before updating to new
548          * assignments, to be released in transport_free_pages() ->
549          * transport_reset_sgl_orig()
550          */
551         cmd->t_data_sg_orig = cmd->t_data_sg;
552         cmd->t_data_sg = write_sg;
553         cmd->t_data_nents_orig = cmd->t_data_nents;
554         cmd->t_data_nents = 1;
555
556         cmd->sam_task_attr = TCM_HEAD_TAG;
557         cmd->transport_complete_callback = compare_and_write_post;
558         /*
559          * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
560          * for submitting the adjusted SGL to write instance user-data.
561          */
562         cmd->execute_cmd = sbc_execute_rw;
563
564         spin_lock_irq(&cmd->t_state_lock);
565         cmd->t_state = TRANSPORT_PROCESSING;
566         cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
567         spin_unlock_irq(&cmd->t_state_lock);
568
569         __target_execute_cmd(cmd, false);
570
571         kfree(buf);
572         return ret;
573
574 miscompare:
575         pr_warn("Target/%s: Send MISCOMPARE check condition and sense\n",
576                 dev->transport->name);
577         ret = TCM_MISCOMPARE_VERIFY;
578 out:
579         /*
580          * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
581          * sbc_compare_and_write() before the original READ I/O submission.
582          */
583         up(&dev->caw_sem);
584         sg_free_table(&write_tbl);
585         kfree(buf);
586         return ret;
587 }
588
589 static sense_reason_t
590 sbc_compare_and_write(struct se_cmd *cmd)
591 {
592         struct sbc_ops *ops = cmd->protocol_data;
593         struct se_device *dev = cmd->se_dev;
594         sense_reason_t ret;
595         int rc;
596         /*
597          * Submit the READ first for COMPARE_AND_WRITE to perform the
598          * comparision using SGLs at cmd->t_bidi_data_sg..
599          */
600         rc = down_interruptible(&dev->caw_sem);
601         if (rc != 0) {
602                 cmd->transport_complete_callback = NULL;
603                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
604         }
605         /*
606          * Reset cmd->data_length to individual block_size in order to not
607          * confuse backend drivers that depend on this value matching the
608          * size of the I/O being submitted.
609          */
610         cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
611
612         ret = ops->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
613                               DMA_FROM_DEVICE);
614         if (ret) {
615                 cmd->transport_complete_callback = NULL;
616                 up(&dev->caw_sem);
617                 return ret;
618         }
619         /*
620          * Unlock of dev->caw_sem to occur in compare_and_write_callback()
621          * upon MISCOMPARE, or in compare_and_write_done() upon completion
622          * of WRITE instance user-data.
623          */
624         return TCM_NO_SENSE;
625 }
626
627 static int
628 sbc_set_prot_op_checks(u8 protect, bool fabric_prot, enum target_prot_type prot_type,
629                        bool is_write, struct se_cmd *cmd)
630 {
631         if (is_write) {
632                 cmd->prot_op = fabric_prot ? TARGET_PROT_DOUT_STRIP :
633                                protect ? TARGET_PROT_DOUT_PASS :
634                                TARGET_PROT_DOUT_INSERT;
635                 switch (protect) {
636                 case 0x0:
637                 case 0x3:
638                         cmd->prot_checks = 0;
639                         break;
640                 case 0x1:
641                 case 0x5:
642                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
643                         if (prot_type == TARGET_DIF_TYPE1_PROT)
644                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
645                         break;
646                 case 0x2:
647                         if (prot_type == TARGET_DIF_TYPE1_PROT)
648                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
649                         break;
650                 case 0x4:
651                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
652                         break;
653                 default:
654                         pr_err("Unsupported protect field %d\n", protect);
655                         return -EINVAL;
656                 }
657         } else {
658                 cmd->prot_op = fabric_prot ? TARGET_PROT_DIN_INSERT :
659                                protect ? TARGET_PROT_DIN_PASS :
660                                TARGET_PROT_DIN_STRIP;
661                 switch (protect) {
662                 case 0x0:
663                 case 0x1:
664                 case 0x5:
665                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
666                         if (prot_type == TARGET_DIF_TYPE1_PROT)
667                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
668                         break;
669                 case 0x2:
670                         if (prot_type == TARGET_DIF_TYPE1_PROT)
671                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
672                         break;
673                 case 0x3:
674                         cmd->prot_checks = 0;
675                         break;
676                 case 0x4:
677                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
678                         break;
679                 default:
680                         pr_err("Unsupported protect field %d\n", protect);
681                         return -EINVAL;
682                 }
683         }
684
685         return 0;
686 }
687
688 static sense_reason_t
689 sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb,
690                u32 sectors, bool is_write)
691 {
692         u8 protect = cdb[1] >> 5;
693         int sp_ops = cmd->se_sess->sup_prot_ops;
694         int pi_prot_type = dev->dev_attrib.pi_prot_type;
695         bool fabric_prot = false;
696
697         if (!cmd->t_prot_sg || !cmd->t_prot_nents) {
698                 if (unlikely(protect &&
699                     !dev->dev_attrib.pi_prot_type && !cmd->se_sess->sess_prot_type)) {
700                         pr_err("CDB contains protect bit, but device + fabric does"
701                                " not advertise PROTECT=1 feature bit\n");
702                         return TCM_INVALID_CDB_FIELD;
703                 }
704                 if (cmd->prot_pto)
705                         return TCM_NO_SENSE;
706         }
707
708         switch (dev->dev_attrib.pi_prot_type) {
709         case TARGET_DIF_TYPE3_PROT:
710                 cmd->reftag_seed = 0xffffffff;
711                 break;
712         case TARGET_DIF_TYPE2_PROT:
713                 if (protect)
714                         return TCM_INVALID_CDB_FIELD;
715
716                 cmd->reftag_seed = cmd->t_task_lba;
717                 break;
718         case TARGET_DIF_TYPE1_PROT:
719                 cmd->reftag_seed = cmd->t_task_lba;
720                 break;
721         case TARGET_DIF_TYPE0_PROT:
722                 /*
723                  * See if the fabric supports T10-PI, and the session has been
724                  * configured to allow export PROTECT=1 feature bit with backend
725                  * devices that don't support T10-PI.
726                  */
727                 fabric_prot = is_write ?
728                               !!(sp_ops & (TARGET_PROT_DOUT_PASS | TARGET_PROT_DOUT_STRIP)) :
729                               !!(sp_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DIN_INSERT));
730
731                 if (fabric_prot && cmd->se_sess->sess_prot_type) {
732                         pi_prot_type = cmd->se_sess->sess_prot_type;
733                         break;
734                 }
735                 if (!protect)
736                         return TCM_NO_SENSE;
737                 fallthrough;
738         default:
739                 pr_err("Unable to determine pi_prot_type for CDB: 0x%02x "
740                        "PROTECT: 0x%02x\n", cdb[0], protect);
741                 return TCM_INVALID_CDB_FIELD;
742         }
743
744         if (sbc_set_prot_op_checks(protect, fabric_prot, pi_prot_type, is_write, cmd))
745                 return TCM_INVALID_CDB_FIELD;
746
747         cmd->prot_type = pi_prot_type;
748         cmd->prot_length = dev->prot_length * sectors;
749
750         /**
751          * In case protection information exists over the wire
752          * we modify command data length to describe pure data.
753          * The actual transfer length is data length + protection
754          * length
755          **/
756         if (protect)
757                 cmd->data_length = sectors * dev->dev_attrib.block_size;
758
759         pr_debug("%s: prot_type=%d, data_length=%d, prot_length=%d "
760                  "prot_op=%d prot_checks=%d\n",
761                  __func__, cmd->prot_type, cmd->data_length, cmd->prot_length,
762                  cmd->prot_op, cmd->prot_checks);
763
764         return TCM_NO_SENSE;
765 }
766
767 static int
768 sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
769 {
770         if (cdb[1] & 0x10) {
771                 /* see explanation in spc_emulate_modesense */
772                 if (!target_check_fua(dev)) {
773                         pr_err("Got CDB: 0x%02x with DPO bit set, but device"
774                                " does not advertise support for DPO\n", cdb[0]);
775                         return -EINVAL;
776                 }
777         }
778         if (cdb[1] & 0x8) {
779                 if (!target_check_fua(dev)) {
780                         pr_err("Got CDB: 0x%02x with FUA bit set, but device"
781                                " does not advertise support for FUA write\n",
782                                cdb[0]);
783                         return -EINVAL;
784                 }
785                 cmd->se_cmd_flags |= SCF_FUA;
786         }
787         return 0;
788 }
789
790 sense_reason_t
791 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
792 {
793         struct se_device *dev = cmd->se_dev;
794         unsigned char *cdb = cmd->t_task_cdb;
795         unsigned int size;
796         u32 sectors = 0;
797         sense_reason_t ret;
798
799         cmd->protocol_data = ops;
800
801         switch (cdb[0]) {
802         case READ_6:
803                 sectors = transport_get_sectors_6(cdb);
804                 cmd->t_task_lba = transport_lba_21(cdb);
805                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
806                 cmd->execute_cmd = sbc_execute_rw;
807                 break;
808         case READ_10:
809                 sectors = transport_get_sectors_10(cdb);
810                 cmd->t_task_lba = transport_lba_32(cdb);
811
812                 if (sbc_check_dpofua(dev, cmd, cdb))
813                         return TCM_INVALID_CDB_FIELD;
814
815                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
816                 if (ret)
817                         return ret;
818
819                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
820                 cmd->execute_cmd = sbc_execute_rw;
821                 break;
822         case READ_12:
823                 sectors = transport_get_sectors_12(cdb);
824                 cmd->t_task_lba = transport_lba_32(cdb);
825
826                 if (sbc_check_dpofua(dev, cmd, cdb))
827                         return TCM_INVALID_CDB_FIELD;
828
829                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
830                 if (ret)
831                         return ret;
832
833                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
834                 cmd->execute_cmd = sbc_execute_rw;
835                 break;
836         case READ_16:
837                 sectors = transport_get_sectors_16(cdb);
838                 cmd->t_task_lba = transport_lba_64(cdb);
839
840                 if (sbc_check_dpofua(dev, cmd, cdb))
841                         return TCM_INVALID_CDB_FIELD;
842
843                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
844                 if (ret)
845                         return ret;
846
847                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
848                 cmd->execute_cmd = sbc_execute_rw;
849                 break;
850         case WRITE_6:
851                 sectors = transport_get_sectors_6(cdb);
852                 cmd->t_task_lba = transport_lba_21(cdb);
853                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
854                 cmd->execute_cmd = sbc_execute_rw;
855                 break;
856         case WRITE_10:
857         case WRITE_VERIFY:
858                 sectors = transport_get_sectors_10(cdb);
859                 cmd->t_task_lba = transport_lba_32(cdb);
860
861                 if (sbc_check_dpofua(dev, cmd, cdb))
862                         return TCM_INVALID_CDB_FIELD;
863
864                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
865                 if (ret)
866                         return ret;
867
868                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
869                 cmd->execute_cmd = sbc_execute_rw;
870                 break;
871         case WRITE_12:
872                 sectors = transport_get_sectors_12(cdb);
873                 cmd->t_task_lba = transport_lba_32(cdb);
874
875                 if (sbc_check_dpofua(dev, cmd, cdb))
876                         return TCM_INVALID_CDB_FIELD;
877
878                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
879                 if (ret)
880                         return ret;
881
882                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
883                 cmd->execute_cmd = sbc_execute_rw;
884                 break;
885         case WRITE_16:
886         case WRITE_VERIFY_16:
887                 sectors = transport_get_sectors_16(cdb);
888                 cmd->t_task_lba = transport_lba_64(cdb);
889
890                 if (sbc_check_dpofua(dev, cmd, cdb))
891                         return TCM_INVALID_CDB_FIELD;
892
893                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
894                 if (ret)
895                         return ret;
896
897                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
898                 cmd->execute_cmd = sbc_execute_rw;
899                 break;
900         case XDWRITEREAD_10:
901                 if (cmd->data_direction != DMA_TO_DEVICE ||
902                     !(cmd->se_cmd_flags & SCF_BIDI))
903                         return TCM_INVALID_CDB_FIELD;
904                 sectors = transport_get_sectors_10(cdb);
905
906                 if (sbc_check_dpofua(dev, cmd, cdb))
907                         return TCM_INVALID_CDB_FIELD;
908
909                 cmd->t_task_lba = transport_lba_32(cdb);
910                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
911
912                 /*
913                  * Setup BIDI XOR callback to be run after I/O completion.
914                  */
915                 cmd->execute_cmd = sbc_execute_rw;
916                 cmd->transport_complete_callback = &xdreadwrite_callback;
917                 break;
918         case VARIABLE_LENGTH_CMD:
919         {
920                 u16 service_action = get_unaligned_be16(&cdb[8]);
921                 switch (service_action) {
922                 case XDWRITEREAD_32:
923                         sectors = transport_get_sectors_32(cdb);
924
925                         if (sbc_check_dpofua(dev, cmd, cdb))
926                                 return TCM_INVALID_CDB_FIELD;
927                         /*
928                          * Use WRITE_32 and READ_32 opcodes for the emulated
929                          * XDWRITE_READ_32 logic.
930                          */
931                         cmd->t_task_lba = transport_lba_64_ext(cdb);
932                         cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
933
934                         /*
935                          * Setup BIDI XOR callback to be run during after I/O
936                          * completion.
937                          */
938                         cmd->execute_cmd = sbc_execute_rw;
939                         cmd->transport_complete_callback = &xdreadwrite_callback;
940                         break;
941                 case WRITE_SAME_32:
942                         sectors = transport_get_sectors_32(cdb);
943                         if (!sectors) {
944                                 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
945                                        " supported\n");
946                                 return TCM_INVALID_CDB_FIELD;
947                         }
948
949                         size = sbc_get_size(cmd, 1);
950                         cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
951
952                         ret = sbc_setup_write_same(cmd, &cdb[10], ops);
953                         if (ret)
954                                 return ret;
955                         break;
956                 default:
957                         pr_err("VARIABLE_LENGTH_CMD service action"
958                                 " 0x%04x not supported\n", service_action);
959                         return TCM_UNSUPPORTED_SCSI_OPCODE;
960                 }
961                 break;
962         }
963         case COMPARE_AND_WRITE:
964                 if (!dev->dev_attrib.emulate_caw) {
965                         pr_err_ratelimited("se_device %s/%s (vpd_unit_serial %s) reject COMPARE_AND_WRITE\n",
966                                            dev->se_hba->backend->ops->name,
967                                            config_item_name(&dev->dev_group.cg_item),
968                                            dev->t10_wwn.unit_serial);
969                         return TCM_UNSUPPORTED_SCSI_OPCODE;
970                 }
971                 sectors = cdb[13];
972                 /*
973                  * Currently enforce COMPARE_AND_WRITE for a single sector
974                  */
975                 if (sectors > 1) {
976                         pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
977                                " than 1\n", sectors);
978                         return TCM_INVALID_CDB_FIELD;
979                 }
980                 if (sbc_check_dpofua(dev, cmd, cdb))
981                         return TCM_INVALID_CDB_FIELD;
982
983                 /*
984                  * Double size because we have two buffers, note that
985                  * zero is not an error..
986                  */
987                 size = 2 * sbc_get_size(cmd, sectors);
988                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
989                 cmd->t_task_nolb = sectors;
990                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
991                 cmd->execute_cmd = sbc_compare_and_write;
992                 cmd->transport_complete_callback = compare_and_write_callback;
993                 break;
994         case READ_CAPACITY:
995                 size = READ_CAP_LEN;
996                 cmd->execute_cmd = sbc_emulate_readcapacity;
997                 break;
998         case SERVICE_ACTION_IN_16:
999                 switch (cmd->t_task_cdb[1] & 0x1f) {
1000                 case SAI_READ_CAPACITY_16:
1001                         cmd->execute_cmd = sbc_emulate_readcapacity_16;
1002                         break;
1003                 case SAI_REPORT_REFERRALS:
1004                         cmd->execute_cmd = target_emulate_report_referrals;
1005                         break;
1006                 default:
1007                         pr_err("Unsupported SA: 0x%02x\n",
1008                                 cmd->t_task_cdb[1] & 0x1f);
1009                         return TCM_INVALID_CDB_FIELD;
1010                 }
1011                 size = get_unaligned_be32(&cdb[10]);
1012                 break;
1013         case SYNCHRONIZE_CACHE:
1014         case SYNCHRONIZE_CACHE_16:
1015                 if (cdb[0] == SYNCHRONIZE_CACHE) {
1016                         sectors = transport_get_sectors_10(cdb);
1017                         cmd->t_task_lba = transport_lba_32(cdb);
1018                 } else {
1019                         sectors = transport_get_sectors_16(cdb);
1020                         cmd->t_task_lba = transport_lba_64(cdb);
1021                 }
1022                 if (ops->execute_sync_cache) {
1023                         cmd->execute_cmd = ops->execute_sync_cache;
1024                         goto check_lba;
1025                 }
1026                 size = 0;
1027                 cmd->execute_cmd = sbc_emulate_noop;
1028                 break;
1029         case UNMAP:
1030                 if (!ops->execute_unmap)
1031                         return TCM_UNSUPPORTED_SCSI_OPCODE;
1032
1033                 if (!dev->dev_attrib.emulate_tpu) {
1034                         pr_err("Got UNMAP, but backend device has"
1035                                " emulate_tpu disabled\n");
1036                         return TCM_UNSUPPORTED_SCSI_OPCODE;
1037                 }
1038                 size = get_unaligned_be16(&cdb[7]);
1039                 cmd->execute_cmd = sbc_execute_unmap;
1040                 break;
1041         case WRITE_SAME_16:
1042                 sectors = transport_get_sectors_16(cdb);
1043                 if (!sectors) {
1044                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1045                         return TCM_INVALID_CDB_FIELD;
1046                 }
1047
1048                 size = sbc_get_size(cmd, 1);
1049                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
1050
1051                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
1052                 if (ret)
1053                         return ret;
1054                 break;
1055         case WRITE_SAME:
1056                 sectors = transport_get_sectors_10(cdb);
1057                 if (!sectors) {
1058                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1059                         return TCM_INVALID_CDB_FIELD;
1060                 }
1061
1062                 size = sbc_get_size(cmd, 1);
1063                 cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
1064
1065                 /*
1066                  * Follow sbcr26 with WRITE_SAME (10) and check for the existence
1067                  * of byte 1 bit 3 UNMAP instead of original reserved field
1068                  */
1069                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
1070                 if (ret)
1071                         return ret;
1072                 break;
1073         case VERIFY:
1074         case VERIFY_16:
1075                 size = 0;
1076                 if (cdb[0] == VERIFY) {
1077                         sectors = transport_get_sectors_10(cdb);
1078                         cmd->t_task_lba = transport_lba_32(cdb);
1079                 } else {
1080                         sectors = transport_get_sectors_16(cdb);
1081                         cmd->t_task_lba = transport_lba_64(cdb);
1082                 }
1083                 cmd->execute_cmd = sbc_emulate_noop;
1084                 goto check_lba;
1085         case REZERO_UNIT:
1086         case SEEK_6:
1087         case SEEK_10:
1088                 /*
1089                  * There are still clients out there which use these old SCSI-2
1090                  * commands. This mainly happens when running VMs with legacy
1091                  * guest systems, connected via SCSI command pass-through to
1092                  * iSCSI targets. Make them happy and return status GOOD.
1093                  */
1094                 size = 0;
1095                 cmd->execute_cmd = sbc_emulate_noop;
1096                 break;
1097         case START_STOP:
1098                 size = 0;
1099                 cmd->execute_cmd = sbc_emulate_startstop;
1100                 break;
1101         default:
1102                 ret = spc_parse_cdb(cmd, &size);
1103                 if (ret)
1104                         return ret;
1105         }
1106
1107         /* reject any command that we don't have a handler for */
1108         if (!cmd->execute_cmd)
1109                 return TCM_UNSUPPORTED_SCSI_OPCODE;
1110
1111         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1112                 unsigned long long end_lba;
1113 check_lba:
1114                 end_lba = dev->transport->get_blocks(dev) + 1;
1115                 if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
1116                     ((cmd->t_task_lba + sectors) > end_lba)) {
1117                         pr_err("cmd exceeds last lba %llu "
1118                                 "(lba %llu, sectors %u)\n",
1119                                 end_lba, cmd->t_task_lba, sectors);
1120                         return TCM_ADDRESS_OUT_OF_RANGE;
1121                 }
1122
1123                 if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
1124                         size = sbc_get_size(cmd, sectors);
1125         }
1126
1127         return target_cmd_size_check(cmd, size);
1128 }
1129 EXPORT_SYMBOL(sbc_parse_cdb);
1130
1131 u32 sbc_get_device_type(struct se_device *dev)
1132 {
1133         return TYPE_DISK;
1134 }
1135 EXPORT_SYMBOL(sbc_get_device_type);
1136
1137 static sense_reason_t
1138 sbc_execute_unmap(struct se_cmd *cmd)
1139 {
1140         struct sbc_ops *ops = cmd->protocol_data;
1141         struct se_device *dev = cmd->se_dev;
1142         unsigned char *buf, *ptr = NULL;
1143         sector_t lba;
1144         int size;
1145         u32 range;
1146         sense_reason_t ret = 0;
1147         int dl, bd_dl;
1148
1149         /* We never set ANC_SUP */
1150         if (cmd->t_task_cdb[1])
1151                 return TCM_INVALID_CDB_FIELD;
1152
1153         if (cmd->data_length == 0) {
1154                 target_complete_cmd(cmd, SAM_STAT_GOOD);
1155                 return 0;
1156         }
1157
1158         if (cmd->data_length < 8) {
1159                 pr_warn("UNMAP parameter list length %u too small\n",
1160                         cmd->data_length);
1161                 return TCM_PARAMETER_LIST_LENGTH_ERROR;
1162         }
1163
1164         buf = transport_kmap_data_sg(cmd);
1165         if (!buf)
1166                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1167
1168         dl = get_unaligned_be16(&buf[0]);
1169         bd_dl = get_unaligned_be16(&buf[2]);
1170
1171         size = cmd->data_length - 8;
1172         if (bd_dl > size)
1173                 pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
1174                         cmd->data_length, bd_dl);
1175         else
1176                 size = bd_dl;
1177
1178         if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
1179                 ret = TCM_INVALID_PARAMETER_LIST;
1180                 goto err;
1181         }
1182
1183         /* First UNMAP block descriptor starts at 8 byte offset */
1184         ptr = &buf[8];
1185         pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
1186                 " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
1187
1188         while (size >= 16) {
1189                 lba = get_unaligned_be64(&ptr[0]);
1190                 range = get_unaligned_be32(&ptr[8]);
1191                 pr_debug("UNMAP: Using lba: %llu and range: %u\n",
1192                                  (unsigned long long)lba, range);
1193
1194                 if (range > dev->dev_attrib.max_unmap_lba_count) {
1195                         ret = TCM_INVALID_PARAMETER_LIST;
1196                         goto err;
1197                 }
1198
1199                 if (lba + range > dev->transport->get_blocks(dev) + 1) {
1200                         ret = TCM_ADDRESS_OUT_OF_RANGE;
1201                         goto err;
1202                 }
1203
1204                 if (range) {
1205                         ret = ops->execute_unmap(cmd, lba, range);
1206                         if (ret)
1207                                 goto err;
1208                 }
1209
1210                 ptr += 16;
1211                 size -= 16;
1212         }
1213
1214 err:
1215         transport_kunmap_data_sg(cmd);
1216         if (!ret)
1217                 target_complete_cmd(cmd, GOOD);
1218         return ret;
1219 }
1220
1221 void
1222 sbc_dif_generate(struct se_cmd *cmd)
1223 {
1224         struct se_device *dev = cmd->se_dev;
1225         struct t10_pi_tuple *sdt;
1226         struct scatterlist *dsg = cmd->t_data_sg, *psg;
1227         sector_t sector = cmd->t_task_lba;
1228         void *daddr, *paddr;
1229         int i, j, offset = 0;
1230         unsigned int block_size = dev->dev_attrib.block_size;
1231
1232         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1233                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1234                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1235
1236                 for (j = 0; j < psg->length;
1237                                 j += sizeof(*sdt)) {
1238                         __u16 crc;
1239                         unsigned int avail;
1240
1241                         if (offset >= dsg->length) {
1242                                 offset -= dsg->length;
1243                                 kunmap_atomic(daddr - dsg->offset);
1244                                 dsg = sg_next(dsg);
1245                                 if (!dsg) {
1246                                         kunmap_atomic(paddr - psg->offset);
1247                                         return;
1248                                 }
1249                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1250                         }
1251
1252                         sdt = paddr + j;
1253                         avail = min(block_size, dsg->length - offset);
1254                         crc = crc_t10dif(daddr + offset, avail);
1255                         if (avail < block_size) {
1256                                 kunmap_atomic(daddr - dsg->offset);
1257                                 dsg = sg_next(dsg);
1258                                 if (!dsg) {
1259                                         kunmap_atomic(paddr - psg->offset);
1260                                         return;
1261                                 }
1262                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1263                                 offset = block_size - avail;
1264                                 crc = crc_t10dif_update(crc, daddr, offset);
1265                         } else {
1266                                 offset += block_size;
1267                         }
1268
1269                         sdt->guard_tag = cpu_to_be16(crc);
1270                         if (cmd->prot_type == TARGET_DIF_TYPE1_PROT)
1271                                 sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
1272                         sdt->app_tag = 0;
1273
1274                         pr_debug("DIF %s INSERT sector: %llu guard_tag: 0x%04x"
1275                                  " app_tag: 0x%04x ref_tag: %u\n",
1276                                  (cmd->data_direction == DMA_TO_DEVICE) ?
1277                                  "WRITE" : "READ", (unsigned long long)sector,
1278                                  sdt->guard_tag, sdt->app_tag,
1279                                  be32_to_cpu(sdt->ref_tag));
1280
1281                         sector++;
1282                 }
1283
1284                 kunmap_atomic(daddr - dsg->offset);
1285                 kunmap_atomic(paddr - psg->offset);
1286         }
1287 }
1288
1289 static sense_reason_t
1290 sbc_dif_v1_verify(struct se_cmd *cmd, struct t10_pi_tuple *sdt,
1291                   __u16 crc, sector_t sector, unsigned int ei_lba)
1292 {
1293         __be16 csum;
1294
1295         if (!(cmd->prot_checks & TARGET_DIF_CHECK_GUARD))
1296                 goto check_ref;
1297
1298         csum = cpu_to_be16(crc);
1299
1300         if (sdt->guard_tag != csum) {
1301                 pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1302                         " csum 0x%04x\n", (unsigned long long)sector,
1303                         be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1304                 return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1305         }
1306
1307 check_ref:
1308         if (!(cmd->prot_checks & TARGET_DIF_CHECK_REFTAG))
1309                 return 0;
1310
1311         if (cmd->prot_type == TARGET_DIF_TYPE1_PROT &&
1312             be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1313                 pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1314                        " sector MSB: 0x%08x\n", (unsigned long long)sector,
1315                        be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1316                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1317         }
1318
1319         if (cmd->prot_type == TARGET_DIF_TYPE2_PROT &&
1320             be32_to_cpu(sdt->ref_tag) != ei_lba) {
1321                 pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1322                        " ei_lba: 0x%08x\n", (unsigned long long)sector,
1323                         be32_to_cpu(sdt->ref_tag), ei_lba);
1324                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1325         }
1326
1327         return 0;
1328 }
1329
1330 void sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1331                        struct scatterlist *sg, int sg_off)
1332 {
1333         struct se_device *dev = cmd->se_dev;
1334         struct scatterlist *psg;
1335         void *paddr, *addr;
1336         unsigned int i, len, left;
1337         unsigned int offset = sg_off;
1338
1339         if (!sg)
1340                 return;
1341
1342         left = sectors * dev->prot_length;
1343
1344         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1345                 unsigned int psg_len, copied = 0;
1346
1347                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1348                 psg_len = min(left, psg->length);
1349                 while (psg_len) {
1350                         len = min(psg_len, sg->length - offset);
1351                         addr = kmap_atomic(sg_page(sg)) + sg->offset + offset;
1352
1353                         if (read)
1354                                 memcpy(paddr + copied, addr, len);
1355                         else
1356                                 memcpy(addr, paddr + copied, len);
1357
1358                         left -= len;
1359                         offset += len;
1360                         copied += len;
1361                         psg_len -= len;
1362
1363                         kunmap_atomic(addr - sg->offset - offset);
1364
1365                         if (offset >= sg->length) {
1366                                 sg = sg_next(sg);
1367                                 offset = 0;
1368                         }
1369                 }
1370                 kunmap_atomic(paddr - psg->offset);
1371         }
1372 }
1373 EXPORT_SYMBOL(sbc_dif_copy_prot);
1374
1375 sense_reason_t
1376 sbc_dif_verify(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1377                unsigned int ei_lba, struct scatterlist *psg, int psg_off)
1378 {
1379         struct se_device *dev = cmd->se_dev;
1380         struct t10_pi_tuple *sdt;
1381         struct scatterlist *dsg = cmd->t_data_sg;
1382         sector_t sector = start;
1383         void *daddr, *paddr;
1384         int i;
1385         sense_reason_t rc;
1386         int dsg_off = 0;
1387         unsigned int block_size = dev->dev_attrib.block_size;
1388
1389         for (; psg && sector < start + sectors; psg = sg_next(psg)) {
1390                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1391                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1392
1393                 for (i = psg_off; i < psg->length &&
1394                                 sector < start + sectors;
1395                                 i += sizeof(*sdt)) {
1396                         __u16 crc;
1397                         unsigned int avail;
1398
1399                         if (dsg_off >= dsg->length) {
1400                                 dsg_off -= dsg->length;
1401                                 kunmap_atomic(daddr - dsg->offset);
1402                                 dsg = sg_next(dsg);
1403                                 if (!dsg) {
1404                                         kunmap_atomic(paddr - psg->offset);
1405                                         return 0;
1406                                 }
1407                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1408                         }
1409
1410                         sdt = paddr + i;
1411
1412                         pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1413                                  " app_tag: 0x%04x ref_tag: %u\n",
1414                                  (unsigned long long)sector, sdt->guard_tag,
1415                                  sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1416
1417                         if (sdt->app_tag == T10_PI_APP_ESCAPE) {
1418                                 dsg_off += block_size;
1419                                 goto next;
1420                         }
1421
1422                         avail = min(block_size, dsg->length - dsg_off);
1423                         crc = crc_t10dif(daddr + dsg_off, avail);
1424                         if (avail < block_size) {
1425                                 kunmap_atomic(daddr - dsg->offset);
1426                                 dsg = sg_next(dsg);
1427                                 if (!dsg) {
1428                                         kunmap_atomic(paddr - psg->offset);
1429                                         return 0;
1430                                 }
1431                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1432                                 dsg_off = block_size - avail;
1433                                 crc = crc_t10dif_update(crc, daddr, dsg_off);
1434                         } else {
1435                                 dsg_off += block_size;
1436                         }
1437
1438                         rc = sbc_dif_v1_verify(cmd, sdt, crc, sector, ei_lba);
1439                         if (rc) {
1440                                 kunmap_atomic(daddr - dsg->offset);
1441                                 kunmap_atomic(paddr - psg->offset);
1442                                 cmd->bad_sector = sector;
1443                                 return rc;
1444                         }
1445 next:
1446                         sector++;
1447                         ei_lba++;
1448                 }
1449
1450                 psg_off = 0;
1451                 kunmap_atomic(daddr - dsg->offset);
1452                 kunmap_atomic(paddr - psg->offset);
1453         }
1454
1455         return 0;
1456 }
1457 EXPORT_SYMBOL(sbc_dif_verify);