Merge tag 'staging-4.1-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh...
[sfrench/cifs-2.6.git] / drivers / target / target_core_sbc.c
1 /*
2  * SCSI Block Commands (SBC) parsing and emulation.
3  *
4  * (c) Copyright 2002-2013 Datera, Inc.
5  *
6  * Nicholas A. Bellinger <nab@kernel.org>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
21  */
22
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/ratelimit.h>
26 #include <linux/crc-t10dif.h>
27 #include <asm/unaligned.h>
28 #include <scsi/scsi.h>
29 #include <scsi/scsi_tcq.h>
30
31 #include <target/target_core_base.h>
32 #include <target/target_core_backend.h>
33 #include <target/target_core_fabric.h>
34
35 #include "target_core_internal.h"
36 #include "target_core_ua.h"
37 #include "target_core_alua.h"
38
39 static sense_reason_t
40 sbc_check_prot(struct se_device *, struct se_cmd *, unsigned char *, u32, bool);
41
42 static sense_reason_t
43 sbc_emulate_readcapacity(struct se_cmd *cmd)
44 {
45         struct se_device *dev = cmd->se_dev;
46         unsigned char *cdb = cmd->t_task_cdb;
47         unsigned long long blocks_long = dev->transport->get_blocks(dev);
48         unsigned char *rbuf;
49         unsigned char buf[8];
50         u32 blocks;
51
52         /*
53          * SBC-2 says:
54          *   If the PMI bit is set to zero and the LOGICAL BLOCK
55          *   ADDRESS field is not set to zero, the device server shall
56          *   terminate the command with CHECK CONDITION status with
57          *   the sense key set to ILLEGAL REQUEST and the additional
58          *   sense code set to INVALID FIELD IN CDB.
59          *
60          * In SBC-3, these fields are obsolete, but some SCSI
61          * compliance tests actually check this, so we might as well
62          * follow SBC-2.
63          */
64         if (!(cdb[8] & 1) && !!(cdb[2] | cdb[3] | cdb[4] | cdb[5]))
65                 return TCM_INVALID_CDB_FIELD;
66
67         if (blocks_long >= 0x00000000ffffffff)
68                 blocks = 0xffffffff;
69         else
70                 blocks = (u32)blocks_long;
71
72         buf[0] = (blocks >> 24) & 0xff;
73         buf[1] = (blocks >> 16) & 0xff;
74         buf[2] = (blocks >> 8) & 0xff;
75         buf[3] = blocks & 0xff;
76         buf[4] = (dev->dev_attrib.block_size >> 24) & 0xff;
77         buf[5] = (dev->dev_attrib.block_size >> 16) & 0xff;
78         buf[6] = (dev->dev_attrib.block_size >> 8) & 0xff;
79         buf[7] = dev->dev_attrib.block_size & 0xff;
80
81         rbuf = transport_kmap_data_sg(cmd);
82         if (rbuf) {
83                 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
84                 transport_kunmap_data_sg(cmd);
85         }
86
87         target_complete_cmd_with_length(cmd, GOOD, 8);
88         return 0;
89 }
90
91 static sense_reason_t
92 sbc_emulate_readcapacity_16(struct se_cmd *cmd)
93 {
94         struct se_device *dev = cmd->se_dev;
95         struct se_session *sess = cmd->se_sess;
96         int pi_prot_type = dev->dev_attrib.pi_prot_type;
97
98         unsigned char *rbuf;
99         unsigned char buf[32];
100         unsigned long long blocks = dev->transport->get_blocks(dev);
101
102         memset(buf, 0, sizeof(buf));
103         buf[0] = (blocks >> 56) & 0xff;
104         buf[1] = (blocks >> 48) & 0xff;
105         buf[2] = (blocks >> 40) & 0xff;
106         buf[3] = (blocks >> 32) & 0xff;
107         buf[4] = (blocks >> 24) & 0xff;
108         buf[5] = (blocks >> 16) & 0xff;
109         buf[6] = (blocks >> 8) & 0xff;
110         buf[7] = blocks & 0xff;
111         buf[8] = (dev->dev_attrib.block_size >> 24) & 0xff;
112         buf[9] = (dev->dev_attrib.block_size >> 16) & 0xff;
113         buf[10] = (dev->dev_attrib.block_size >> 8) & 0xff;
114         buf[11] = dev->dev_attrib.block_size & 0xff;
115         /*
116          * Set P_TYPE and PROT_EN bits for DIF support
117          */
118         if (sess->sup_prot_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS)) {
119                 /*
120                  * Only override a device's pi_prot_type if no T10-PI is
121                  * available, and sess_prot_type has been explicitly enabled.
122                  */
123                 if (!pi_prot_type)
124                         pi_prot_type = sess->sess_prot_type;
125
126                 if (pi_prot_type)
127                         buf[12] = (pi_prot_type - 1) << 1 | 0x1;
128         }
129
130         if (dev->transport->get_lbppbe)
131                 buf[13] = dev->transport->get_lbppbe(dev) & 0x0f;
132
133         if (dev->transport->get_alignment_offset_lbas) {
134                 u16 lalba = dev->transport->get_alignment_offset_lbas(dev);
135                 buf[14] = (lalba >> 8) & 0x3f;
136                 buf[15] = lalba & 0xff;
137         }
138
139         /*
140          * Set Thin Provisioning Enable bit following sbc3r22 in section
141          * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
142          */
143         if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws)
144                 buf[14] |= 0x80;
145
146         rbuf = transport_kmap_data_sg(cmd);
147         if (rbuf) {
148                 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
149                 transport_kunmap_data_sg(cmd);
150         }
151
152         target_complete_cmd_with_length(cmd, GOOD, 32);
153         return 0;
154 }
155
156 sector_t sbc_get_write_same_sectors(struct se_cmd *cmd)
157 {
158         u32 num_blocks;
159
160         if (cmd->t_task_cdb[0] == WRITE_SAME)
161                 num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]);
162         else if (cmd->t_task_cdb[0] == WRITE_SAME_16)
163                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]);
164         else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
165                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]);
166
167         /*
168          * Use the explicit range when non zero is supplied, otherwise calculate
169          * the remaining range based on ->get_blocks() - starting LBA.
170          */
171         if (num_blocks)
172                 return num_blocks;
173
174         return cmd->se_dev->transport->get_blocks(cmd->se_dev) -
175                 cmd->t_task_lba + 1;
176 }
177 EXPORT_SYMBOL(sbc_get_write_same_sectors);
178
179 static sense_reason_t
180 sbc_emulate_noop(struct se_cmd *cmd)
181 {
182         target_complete_cmd(cmd, GOOD);
183         return 0;
184 }
185
186 static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
187 {
188         return cmd->se_dev->dev_attrib.block_size * sectors;
189 }
190
191 static inline u32 transport_get_sectors_6(unsigned char *cdb)
192 {
193         /*
194          * Use 8-bit sector value.  SBC-3 says:
195          *
196          *   A TRANSFER LENGTH field set to zero specifies that 256
197          *   logical blocks shall be written.  Any other value
198          *   specifies the number of logical blocks that shall be
199          *   written.
200          */
201         return cdb[4] ? : 256;
202 }
203
204 static inline u32 transport_get_sectors_10(unsigned char *cdb)
205 {
206         return (u32)(cdb[7] << 8) + cdb[8];
207 }
208
209 static inline u32 transport_get_sectors_12(unsigned char *cdb)
210 {
211         return (u32)(cdb[6] << 24) + (cdb[7] << 16) + (cdb[8] << 8) + cdb[9];
212 }
213
214 static inline u32 transport_get_sectors_16(unsigned char *cdb)
215 {
216         return (u32)(cdb[10] << 24) + (cdb[11] << 16) +
217                     (cdb[12] << 8) + cdb[13];
218 }
219
220 /*
221  * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
222  */
223 static inline u32 transport_get_sectors_32(unsigned char *cdb)
224 {
225         return (u32)(cdb[28] << 24) + (cdb[29] << 16) +
226                     (cdb[30] << 8) + cdb[31];
227
228 }
229
230 static inline u32 transport_lba_21(unsigned char *cdb)
231 {
232         return ((cdb[1] & 0x1f) << 16) | (cdb[2] << 8) | cdb[3];
233 }
234
235 static inline u32 transport_lba_32(unsigned char *cdb)
236 {
237         return (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
238 }
239
240 static inline unsigned long long transport_lba_64(unsigned char *cdb)
241 {
242         unsigned int __v1, __v2;
243
244         __v1 = (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
245         __v2 = (cdb[6] << 24) | (cdb[7] << 16) | (cdb[8] << 8) | cdb[9];
246
247         return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
248 }
249
250 /*
251  * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
252  */
253 static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
254 {
255         unsigned int __v1, __v2;
256
257         __v1 = (cdb[12] << 24) | (cdb[13] << 16) | (cdb[14] << 8) | cdb[15];
258         __v2 = (cdb[16] << 24) | (cdb[17] << 16) | (cdb[18] << 8) | cdb[19];
259
260         return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
261 }
262
263 static sense_reason_t
264 sbc_setup_write_same(struct se_cmd *cmd, unsigned char *flags, struct sbc_ops *ops)
265 {
266         struct se_device *dev = cmd->se_dev;
267         sector_t end_lba = dev->transport->get_blocks(dev) + 1;
268         unsigned int sectors = sbc_get_write_same_sectors(cmd);
269         sense_reason_t ret;
270
271         if ((flags[0] & 0x04) || (flags[0] & 0x02)) {
272                 pr_err("WRITE_SAME PBDATA and LBDATA"
273                         " bits not supported for Block Discard"
274                         " Emulation\n");
275                 return TCM_UNSUPPORTED_SCSI_OPCODE;
276         }
277         if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
278                 pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
279                         sectors, cmd->se_dev->dev_attrib.max_write_same_len);
280                 return TCM_INVALID_CDB_FIELD;
281         }
282         /*
283          * Sanity check for LBA wrap and request past end of device.
284          */
285         if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
286             ((cmd->t_task_lba + sectors) > end_lba)) {
287                 pr_err("WRITE_SAME exceeds last lba %llu (lba %llu, sectors %u)\n",
288                        (unsigned long long)end_lba, cmd->t_task_lba, sectors);
289                 return TCM_ADDRESS_OUT_OF_RANGE;
290         }
291
292         /* We always have ANC_SUP == 0 so setting ANCHOR is always an error */
293         if (flags[0] & 0x10) {
294                 pr_warn("WRITE SAME with ANCHOR not supported\n");
295                 return TCM_INVALID_CDB_FIELD;
296         }
297         /*
298          * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
299          * translated into block discard requests within backend code.
300          */
301         if (flags[0] & 0x08) {
302                 if (!ops->execute_write_same_unmap)
303                         return TCM_UNSUPPORTED_SCSI_OPCODE;
304
305                 if (!dev->dev_attrib.emulate_tpws) {
306                         pr_err("Got WRITE_SAME w/ UNMAP=1, but backend device"
307                                " has emulate_tpws disabled\n");
308                         return TCM_UNSUPPORTED_SCSI_OPCODE;
309                 }
310                 cmd->execute_cmd = ops->execute_write_same_unmap;
311                 return 0;
312         }
313         if (!ops->execute_write_same)
314                 return TCM_UNSUPPORTED_SCSI_OPCODE;
315
316         ret = sbc_check_prot(dev, cmd, &cmd->t_task_cdb[0], sectors, true);
317         if (ret)
318                 return ret;
319
320         cmd->execute_cmd = ops->execute_write_same;
321         return 0;
322 }
323
324 static sense_reason_t xdreadwrite_callback(struct se_cmd *cmd, bool success)
325 {
326         unsigned char *buf, *addr;
327         struct scatterlist *sg;
328         unsigned int offset;
329         sense_reason_t ret = TCM_NO_SENSE;
330         int i, count;
331         /*
332          * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
333          *
334          * 1) read the specified logical block(s);
335          * 2) transfer logical blocks from the data-out buffer;
336          * 3) XOR the logical blocks transferred from the data-out buffer with
337          *    the logical blocks read, storing the resulting XOR data in a buffer;
338          * 4) if the DISABLE WRITE bit is set to zero, then write the logical
339          *    blocks transferred from the data-out buffer; and
340          * 5) transfer the resulting XOR data to the data-in buffer.
341          */
342         buf = kmalloc(cmd->data_length, GFP_KERNEL);
343         if (!buf) {
344                 pr_err("Unable to allocate xor_callback buf\n");
345                 return TCM_OUT_OF_RESOURCES;
346         }
347         /*
348          * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
349          * into the locally allocated *buf
350          */
351         sg_copy_to_buffer(cmd->t_data_sg,
352                           cmd->t_data_nents,
353                           buf,
354                           cmd->data_length);
355
356         /*
357          * Now perform the XOR against the BIDI read memory located at
358          * cmd->t_mem_bidi_list
359          */
360
361         offset = 0;
362         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
363                 addr = kmap_atomic(sg_page(sg));
364                 if (!addr) {
365                         ret = TCM_OUT_OF_RESOURCES;
366                         goto out;
367                 }
368
369                 for (i = 0; i < sg->length; i++)
370                         *(addr + sg->offset + i) ^= *(buf + offset + i);
371
372                 offset += sg->length;
373                 kunmap_atomic(addr);
374         }
375
376 out:
377         kfree(buf);
378         return ret;
379 }
380
381 static sense_reason_t
382 sbc_execute_rw(struct se_cmd *cmd)
383 {
384         return cmd->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
385                                cmd->data_direction);
386 }
387
388 static sense_reason_t compare_and_write_post(struct se_cmd *cmd, bool success)
389 {
390         struct se_device *dev = cmd->se_dev;
391
392         /*
393          * Only set SCF_COMPARE_AND_WRITE_POST to force a response fall-through
394          * within target_complete_ok_work() if the command was successfully
395          * sent to the backend driver.
396          */
397         spin_lock_irq(&cmd->t_state_lock);
398         if ((cmd->transport_state & CMD_T_SENT) && !cmd->scsi_status)
399                 cmd->se_cmd_flags |= SCF_COMPARE_AND_WRITE_POST;
400         spin_unlock_irq(&cmd->t_state_lock);
401
402         /*
403          * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
404          * before the original READ I/O submission.
405          */
406         up(&dev->caw_sem);
407
408         return TCM_NO_SENSE;
409 }
410
411 static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool success)
412 {
413         struct se_device *dev = cmd->se_dev;
414         struct scatterlist *write_sg = NULL, *sg;
415         unsigned char *buf = NULL, *addr;
416         struct sg_mapping_iter m;
417         unsigned int offset = 0, len;
418         unsigned int nlbas = cmd->t_task_nolb;
419         unsigned int block_size = dev->dev_attrib.block_size;
420         unsigned int compare_len = (nlbas * block_size);
421         sense_reason_t ret = TCM_NO_SENSE;
422         int rc, i;
423
424         /*
425          * Handle early failure in transport_generic_request_failure(),
426          * which will not have taken ->caw_sem yet..
427          */
428         if (!success && (!cmd->t_data_sg || !cmd->t_bidi_data_sg))
429                 return TCM_NO_SENSE;
430         /*
431          * Handle special case for zero-length COMPARE_AND_WRITE
432          */
433         if (!cmd->data_length)
434                 goto out;
435         /*
436          * Immediately exit + release dev->caw_sem if command has already
437          * been failed with a non-zero SCSI status.
438          */
439         if (cmd->scsi_status) {
440                 pr_err("compare_and_write_callback: non zero scsi_status:"
441                         " 0x%02x\n", cmd->scsi_status);
442                 goto out;
443         }
444
445         buf = kzalloc(cmd->data_length, GFP_KERNEL);
446         if (!buf) {
447                 pr_err("Unable to allocate compare_and_write buf\n");
448                 ret = TCM_OUT_OF_RESOURCES;
449                 goto out;
450         }
451
452         write_sg = kmalloc(sizeof(struct scatterlist) * cmd->t_data_nents,
453                            GFP_KERNEL);
454         if (!write_sg) {
455                 pr_err("Unable to allocate compare_and_write sg\n");
456                 ret = TCM_OUT_OF_RESOURCES;
457                 goto out;
458         }
459         sg_init_table(write_sg, cmd->t_data_nents);
460         /*
461          * Setup verify and write data payloads from total NumberLBAs.
462          */
463         rc = sg_copy_to_buffer(cmd->t_data_sg, cmd->t_data_nents, buf,
464                                cmd->data_length);
465         if (!rc) {
466                 pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
467                 ret = TCM_OUT_OF_RESOURCES;
468                 goto out;
469         }
470         /*
471          * Compare against SCSI READ payload against verify payload
472          */
473         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, i) {
474                 addr = (unsigned char *)kmap_atomic(sg_page(sg));
475                 if (!addr) {
476                         ret = TCM_OUT_OF_RESOURCES;
477                         goto out;
478                 }
479
480                 len = min(sg->length, compare_len);
481
482                 if (memcmp(addr, buf + offset, len)) {
483                         pr_warn("Detected MISCOMPARE for addr: %p buf: %p\n",
484                                 addr, buf + offset);
485                         kunmap_atomic(addr);
486                         goto miscompare;
487                 }
488                 kunmap_atomic(addr);
489
490                 offset += len;
491                 compare_len -= len;
492                 if (!compare_len)
493                         break;
494         }
495
496         i = 0;
497         len = cmd->t_task_nolb * block_size;
498         sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
499         /*
500          * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
501          */
502         while (len) {
503                 sg_miter_next(&m);
504
505                 if (block_size < PAGE_SIZE) {
506                         sg_set_page(&write_sg[i], m.page, block_size,
507                                     block_size);
508                 } else {
509                         sg_miter_next(&m);
510                         sg_set_page(&write_sg[i], m.page, block_size,
511                                     0);
512                 }
513                 len -= block_size;
514                 i++;
515         }
516         sg_miter_stop(&m);
517         /*
518          * Save the original SGL + nents values before updating to new
519          * assignments, to be released in transport_free_pages() ->
520          * transport_reset_sgl_orig()
521          */
522         cmd->t_data_sg_orig = cmd->t_data_sg;
523         cmd->t_data_sg = write_sg;
524         cmd->t_data_nents_orig = cmd->t_data_nents;
525         cmd->t_data_nents = 1;
526
527         cmd->sam_task_attr = TCM_HEAD_TAG;
528         cmd->transport_complete_callback = compare_and_write_post;
529         /*
530          * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
531          * for submitting the adjusted SGL to write instance user-data.
532          */
533         cmd->execute_cmd = sbc_execute_rw;
534
535         spin_lock_irq(&cmd->t_state_lock);
536         cmd->t_state = TRANSPORT_PROCESSING;
537         cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
538         spin_unlock_irq(&cmd->t_state_lock);
539
540         __target_execute_cmd(cmd);
541
542         kfree(buf);
543         return ret;
544
545 miscompare:
546         pr_warn("Target/%s: Send MISCOMPARE check condition and sense\n",
547                 dev->transport->name);
548         ret = TCM_MISCOMPARE_VERIFY;
549 out:
550         /*
551          * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
552          * sbc_compare_and_write() before the original READ I/O submission.
553          */
554         up(&dev->caw_sem);
555         kfree(write_sg);
556         kfree(buf);
557         return ret;
558 }
559
560 static sense_reason_t
561 sbc_compare_and_write(struct se_cmd *cmd)
562 {
563         struct se_device *dev = cmd->se_dev;
564         sense_reason_t ret;
565         int rc;
566         /*
567          * Submit the READ first for COMPARE_AND_WRITE to perform the
568          * comparision using SGLs at cmd->t_bidi_data_sg..
569          */
570         rc = down_interruptible(&dev->caw_sem);
571         if (rc != 0) {
572                 cmd->transport_complete_callback = NULL;
573                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
574         }
575         /*
576          * Reset cmd->data_length to individual block_size in order to not
577          * confuse backend drivers that depend on this value matching the
578          * size of the I/O being submitted.
579          */
580         cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
581
582         ret = cmd->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
583                               DMA_FROM_DEVICE);
584         if (ret) {
585                 cmd->transport_complete_callback = NULL;
586                 up(&dev->caw_sem);
587                 return ret;
588         }
589         /*
590          * Unlock of dev->caw_sem to occur in compare_and_write_callback()
591          * upon MISCOMPARE, or in compare_and_write_done() upon completion
592          * of WRITE instance user-data.
593          */
594         return TCM_NO_SENSE;
595 }
596
597 static int
598 sbc_set_prot_op_checks(u8 protect, bool fabric_prot, enum target_prot_type prot_type,
599                        bool is_write, struct se_cmd *cmd)
600 {
601         if (is_write) {
602                 cmd->prot_op = fabric_prot ? TARGET_PROT_DOUT_STRIP :
603                                protect ? TARGET_PROT_DOUT_PASS :
604                                TARGET_PROT_DOUT_INSERT;
605                 switch (protect) {
606                 case 0x0:
607                 case 0x3:
608                         cmd->prot_checks = 0;
609                         break;
610                 case 0x1:
611                 case 0x5:
612                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
613                         if (prot_type == TARGET_DIF_TYPE1_PROT)
614                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
615                         break;
616                 case 0x2:
617                         if (prot_type == TARGET_DIF_TYPE1_PROT)
618                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
619                         break;
620                 case 0x4:
621                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
622                         break;
623                 default:
624                         pr_err("Unsupported protect field %d\n", protect);
625                         return -EINVAL;
626                 }
627         } else {
628                 cmd->prot_op = fabric_prot ? TARGET_PROT_DIN_INSERT :
629                                protect ? TARGET_PROT_DIN_PASS :
630                                TARGET_PROT_DIN_STRIP;
631                 switch (protect) {
632                 case 0x0:
633                 case 0x1:
634                 case 0x5:
635                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
636                         if (prot_type == TARGET_DIF_TYPE1_PROT)
637                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
638                         break;
639                 case 0x2:
640                         if (prot_type == TARGET_DIF_TYPE1_PROT)
641                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
642                         break;
643                 case 0x3:
644                         cmd->prot_checks = 0;
645                         break;
646                 case 0x4:
647                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
648                         break;
649                 default:
650                         pr_err("Unsupported protect field %d\n", protect);
651                         return -EINVAL;
652                 }
653         }
654
655         return 0;
656 }
657
658 static sense_reason_t
659 sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb,
660                u32 sectors, bool is_write)
661 {
662         u8 protect = cdb[1] >> 5;
663         int sp_ops = cmd->se_sess->sup_prot_ops;
664         int pi_prot_type = dev->dev_attrib.pi_prot_type;
665         bool fabric_prot = false;
666
667         if (!cmd->t_prot_sg || !cmd->t_prot_nents) {
668                 if (unlikely(protect &&
669                     !dev->dev_attrib.pi_prot_type && !cmd->se_sess->sess_prot_type)) {
670                         pr_err("CDB contains protect bit, but device + fabric does"
671                                " not advertise PROTECT=1 feature bit\n");
672                         return TCM_INVALID_CDB_FIELD;
673                 }
674                 if (cmd->prot_pto)
675                         return TCM_NO_SENSE;
676         }
677
678         switch (dev->dev_attrib.pi_prot_type) {
679         case TARGET_DIF_TYPE3_PROT:
680                 cmd->reftag_seed = 0xffffffff;
681                 break;
682         case TARGET_DIF_TYPE2_PROT:
683                 if (protect)
684                         return TCM_INVALID_CDB_FIELD;
685
686                 cmd->reftag_seed = cmd->t_task_lba;
687                 break;
688         case TARGET_DIF_TYPE1_PROT:
689                 cmd->reftag_seed = cmd->t_task_lba;
690                 break;
691         case TARGET_DIF_TYPE0_PROT:
692                 /*
693                  * See if the fabric supports T10-PI, and the session has been
694                  * configured to allow export PROTECT=1 feature bit with backend
695                  * devices that don't support T10-PI.
696                  */
697                 fabric_prot = is_write ?
698                               !!(sp_ops & (TARGET_PROT_DOUT_PASS | TARGET_PROT_DOUT_STRIP)) :
699                               !!(sp_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DIN_INSERT));
700
701                 if (fabric_prot && cmd->se_sess->sess_prot_type) {
702                         pi_prot_type = cmd->se_sess->sess_prot_type;
703                         break;
704                 }
705                 if (!protect)
706                         return TCM_NO_SENSE;
707                 /* Fallthrough */
708         default:
709                 pr_err("Unable to determine pi_prot_type for CDB: 0x%02x "
710                        "PROTECT: 0x%02x\n", cdb[0], protect);
711                 return TCM_INVALID_CDB_FIELD;
712         }
713
714         if (sbc_set_prot_op_checks(protect, fabric_prot, pi_prot_type, is_write, cmd))
715                 return TCM_INVALID_CDB_FIELD;
716
717         cmd->prot_type = pi_prot_type;
718         cmd->prot_length = dev->prot_length * sectors;
719
720         /**
721          * In case protection information exists over the wire
722          * we modify command data length to describe pure data.
723          * The actual transfer length is data length + protection
724          * length
725          **/
726         if (protect)
727                 cmd->data_length = sectors * dev->dev_attrib.block_size;
728
729         pr_debug("%s: prot_type=%d, data_length=%d, prot_length=%d "
730                  "prot_op=%d prot_checks=%d\n",
731                  __func__, cmd->prot_type, cmd->data_length, cmd->prot_length,
732                  cmd->prot_op, cmd->prot_checks);
733
734         return TCM_NO_SENSE;
735 }
736
737 static int
738 sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
739 {
740         if (cdb[1] & 0x10) {
741                 if (!dev->dev_attrib.emulate_dpo) {
742                         pr_err("Got CDB: 0x%02x with DPO bit set, but device"
743                                " does not advertise support for DPO\n", cdb[0]);
744                         return -EINVAL;
745                 }
746         }
747         if (cdb[1] & 0x8) {
748                 if (!dev->dev_attrib.emulate_fua_write || !se_dev_check_wce(dev)) {
749                         pr_err("Got CDB: 0x%02x with FUA bit set, but device"
750                                " does not advertise support for FUA write\n",
751                                cdb[0]);
752                         return -EINVAL;
753                 }
754                 cmd->se_cmd_flags |= SCF_FUA;
755         }
756         return 0;
757 }
758
759 sense_reason_t
760 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
761 {
762         struct se_device *dev = cmd->se_dev;
763         unsigned char *cdb = cmd->t_task_cdb;
764         unsigned int size;
765         u32 sectors = 0;
766         sense_reason_t ret;
767
768         switch (cdb[0]) {
769         case READ_6:
770                 sectors = transport_get_sectors_6(cdb);
771                 cmd->t_task_lba = transport_lba_21(cdb);
772                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
773                 cmd->execute_rw = ops->execute_rw;
774                 cmd->execute_cmd = sbc_execute_rw;
775                 break;
776         case READ_10:
777                 sectors = transport_get_sectors_10(cdb);
778                 cmd->t_task_lba = transport_lba_32(cdb);
779
780                 if (sbc_check_dpofua(dev, cmd, cdb))
781                         return TCM_INVALID_CDB_FIELD;
782
783                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
784                 if (ret)
785                         return ret;
786
787                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
788                 cmd->execute_rw = ops->execute_rw;
789                 cmd->execute_cmd = sbc_execute_rw;
790                 break;
791         case READ_12:
792                 sectors = transport_get_sectors_12(cdb);
793                 cmd->t_task_lba = transport_lba_32(cdb);
794
795                 if (sbc_check_dpofua(dev, cmd, cdb))
796                         return TCM_INVALID_CDB_FIELD;
797
798                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
799                 if (ret)
800                         return ret;
801
802                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
803                 cmd->execute_rw = ops->execute_rw;
804                 cmd->execute_cmd = sbc_execute_rw;
805                 break;
806         case READ_16:
807                 sectors = transport_get_sectors_16(cdb);
808                 cmd->t_task_lba = transport_lba_64(cdb);
809
810                 if (sbc_check_dpofua(dev, cmd, cdb))
811                         return TCM_INVALID_CDB_FIELD;
812
813                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
814                 if (ret)
815                         return ret;
816
817                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
818                 cmd->execute_rw = ops->execute_rw;
819                 cmd->execute_cmd = sbc_execute_rw;
820                 break;
821         case WRITE_6:
822                 sectors = transport_get_sectors_6(cdb);
823                 cmd->t_task_lba = transport_lba_21(cdb);
824                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
825                 cmd->execute_rw = ops->execute_rw;
826                 cmd->execute_cmd = sbc_execute_rw;
827                 break;
828         case WRITE_10:
829         case WRITE_VERIFY:
830                 sectors = transport_get_sectors_10(cdb);
831                 cmd->t_task_lba = transport_lba_32(cdb);
832
833                 if (sbc_check_dpofua(dev, cmd, cdb))
834                         return TCM_INVALID_CDB_FIELD;
835
836                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
837                 if (ret)
838                         return ret;
839
840                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
841                 cmd->execute_rw = ops->execute_rw;
842                 cmd->execute_cmd = sbc_execute_rw;
843                 break;
844         case WRITE_12:
845                 sectors = transport_get_sectors_12(cdb);
846                 cmd->t_task_lba = transport_lba_32(cdb);
847
848                 if (sbc_check_dpofua(dev, cmd, cdb))
849                         return TCM_INVALID_CDB_FIELD;
850
851                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
852                 if (ret)
853                         return ret;
854
855                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
856                 cmd->execute_rw = ops->execute_rw;
857                 cmd->execute_cmd = sbc_execute_rw;
858                 break;
859         case WRITE_16:
860                 sectors = transport_get_sectors_16(cdb);
861                 cmd->t_task_lba = transport_lba_64(cdb);
862
863                 if (sbc_check_dpofua(dev, cmd, cdb))
864                         return TCM_INVALID_CDB_FIELD;
865
866                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
867                 if (ret)
868                         return ret;
869
870                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
871                 cmd->execute_rw = ops->execute_rw;
872                 cmd->execute_cmd = sbc_execute_rw;
873                 break;
874         case XDWRITEREAD_10:
875                 if (cmd->data_direction != DMA_TO_DEVICE ||
876                     !(cmd->se_cmd_flags & SCF_BIDI))
877                         return TCM_INVALID_CDB_FIELD;
878                 sectors = transport_get_sectors_10(cdb);
879
880                 if (sbc_check_dpofua(dev, cmd, cdb))
881                         return TCM_INVALID_CDB_FIELD;
882
883                 cmd->t_task_lba = transport_lba_32(cdb);
884                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
885
886                 /*
887                  * Setup BIDI XOR callback to be run after I/O completion.
888                  */
889                 cmd->execute_rw = ops->execute_rw;
890                 cmd->execute_cmd = sbc_execute_rw;
891                 cmd->transport_complete_callback = &xdreadwrite_callback;
892                 break;
893         case VARIABLE_LENGTH_CMD:
894         {
895                 u16 service_action = get_unaligned_be16(&cdb[8]);
896                 switch (service_action) {
897                 case XDWRITEREAD_32:
898                         sectors = transport_get_sectors_32(cdb);
899
900                         if (sbc_check_dpofua(dev, cmd, cdb))
901                                 return TCM_INVALID_CDB_FIELD;
902                         /*
903                          * Use WRITE_32 and READ_32 opcodes for the emulated
904                          * XDWRITE_READ_32 logic.
905                          */
906                         cmd->t_task_lba = transport_lba_64_ext(cdb);
907                         cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
908
909                         /*
910                          * Setup BIDI XOR callback to be run during after I/O
911                          * completion.
912                          */
913                         cmd->execute_rw = ops->execute_rw;
914                         cmd->execute_cmd = sbc_execute_rw;
915                         cmd->transport_complete_callback = &xdreadwrite_callback;
916                         break;
917                 case WRITE_SAME_32:
918                         sectors = transport_get_sectors_32(cdb);
919                         if (!sectors) {
920                                 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
921                                        " supported\n");
922                                 return TCM_INVALID_CDB_FIELD;
923                         }
924
925                         size = sbc_get_size(cmd, 1);
926                         cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
927
928                         ret = sbc_setup_write_same(cmd, &cdb[10], ops);
929                         if (ret)
930                                 return ret;
931                         break;
932                 default:
933                         pr_err("VARIABLE_LENGTH_CMD service action"
934                                 " 0x%04x not supported\n", service_action);
935                         return TCM_UNSUPPORTED_SCSI_OPCODE;
936                 }
937                 break;
938         }
939         case COMPARE_AND_WRITE:
940                 sectors = cdb[13];
941                 /*
942                  * Currently enforce COMPARE_AND_WRITE for a single sector
943                  */
944                 if (sectors > 1) {
945                         pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
946                                " than 1\n", sectors);
947                         return TCM_INVALID_CDB_FIELD;
948                 }
949                 /*
950                  * Double size because we have two buffers, note that
951                  * zero is not an error..
952                  */
953                 size = 2 * sbc_get_size(cmd, sectors);
954                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
955                 cmd->t_task_nolb = sectors;
956                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
957                 cmd->execute_rw = ops->execute_rw;
958                 cmd->execute_cmd = sbc_compare_and_write;
959                 cmd->transport_complete_callback = compare_and_write_callback;
960                 break;
961         case READ_CAPACITY:
962                 size = READ_CAP_LEN;
963                 cmd->execute_cmd = sbc_emulate_readcapacity;
964                 break;
965         case SERVICE_ACTION_IN_16:
966                 switch (cmd->t_task_cdb[1] & 0x1f) {
967                 case SAI_READ_CAPACITY_16:
968                         cmd->execute_cmd = sbc_emulate_readcapacity_16;
969                         break;
970                 case SAI_REPORT_REFERRALS:
971                         cmd->execute_cmd = target_emulate_report_referrals;
972                         break;
973                 default:
974                         pr_err("Unsupported SA: 0x%02x\n",
975                                 cmd->t_task_cdb[1] & 0x1f);
976                         return TCM_INVALID_CDB_FIELD;
977                 }
978                 size = (cdb[10] << 24) | (cdb[11] << 16) |
979                        (cdb[12] << 8) | cdb[13];
980                 break;
981         case SYNCHRONIZE_CACHE:
982         case SYNCHRONIZE_CACHE_16:
983                 if (cdb[0] == SYNCHRONIZE_CACHE) {
984                         sectors = transport_get_sectors_10(cdb);
985                         cmd->t_task_lba = transport_lba_32(cdb);
986                 } else {
987                         sectors = transport_get_sectors_16(cdb);
988                         cmd->t_task_lba = transport_lba_64(cdb);
989                 }
990                 if (ops->execute_sync_cache) {
991                         cmd->execute_cmd = ops->execute_sync_cache;
992                         goto check_lba;
993                 }
994                 size = 0;
995                 cmd->execute_cmd = sbc_emulate_noop;
996                 break;
997         case UNMAP:
998                 if (!ops->execute_unmap)
999                         return TCM_UNSUPPORTED_SCSI_OPCODE;
1000
1001                 if (!dev->dev_attrib.emulate_tpu) {
1002                         pr_err("Got UNMAP, but backend device has"
1003                                " emulate_tpu disabled\n");
1004                         return TCM_UNSUPPORTED_SCSI_OPCODE;
1005                 }
1006                 size = get_unaligned_be16(&cdb[7]);
1007                 cmd->execute_cmd = ops->execute_unmap;
1008                 break;
1009         case WRITE_SAME_16:
1010                 sectors = transport_get_sectors_16(cdb);
1011                 if (!sectors) {
1012                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1013                         return TCM_INVALID_CDB_FIELD;
1014                 }
1015
1016                 size = sbc_get_size(cmd, 1);
1017                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
1018
1019                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
1020                 if (ret)
1021                         return ret;
1022                 break;
1023         case WRITE_SAME:
1024                 sectors = transport_get_sectors_10(cdb);
1025                 if (!sectors) {
1026                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1027                         return TCM_INVALID_CDB_FIELD;
1028                 }
1029
1030                 size = sbc_get_size(cmd, 1);
1031                 cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
1032
1033                 /*
1034                  * Follow sbcr26 with WRITE_SAME (10) and check for the existence
1035                  * of byte 1 bit 3 UNMAP instead of original reserved field
1036                  */
1037                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
1038                 if (ret)
1039                         return ret;
1040                 break;
1041         case VERIFY:
1042                 size = 0;
1043                 sectors = transport_get_sectors_10(cdb);
1044                 cmd->t_task_lba = transport_lba_32(cdb);
1045                 cmd->execute_cmd = sbc_emulate_noop;
1046                 goto check_lba;
1047         case REZERO_UNIT:
1048         case SEEK_6:
1049         case SEEK_10:
1050                 /*
1051                  * There are still clients out there which use these old SCSI-2
1052                  * commands. This mainly happens when running VMs with legacy
1053                  * guest systems, connected via SCSI command pass-through to
1054                  * iSCSI targets. Make them happy and return status GOOD.
1055                  */
1056                 size = 0;
1057                 cmd->execute_cmd = sbc_emulate_noop;
1058                 break;
1059         default:
1060                 ret = spc_parse_cdb(cmd, &size);
1061                 if (ret)
1062                         return ret;
1063         }
1064
1065         /* reject any command that we don't have a handler for */
1066         if (!cmd->execute_cmd)
1067                 return TCM_UNSUPPORTED_SCSI_OPCODE;
1068
1069         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1070                 unsigned long long end_lba;
1071 check_lba:
1072                 end_lba = dev->transport->get_blocks(dev) + 1;
1073                 if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
1074                     ((cmd->t_task_lba + sectors) > end_lba)) {
1075                         pr_err("cmd exceeds last lba %llu "
1076                                 "(lba %llu, sectors %u)\n",
1077                                 end_lba, cmd->t_task_lba, sectors);
1078                         return TCM_ADDRESS_OUT_OF_RANGE;
1079                 }
1080
1081                 if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
1082                         size = sbc_get_size(cmd, sectors);
1083         }
1084
1085         return target_cmd_size_check(cmd, size);
1086 }
1087 EXPORT_SYMBOL(sbc_parse_cdb);
1088
1089 u32 sbc_get_device_type(struct se_device *dev)
1090 {
1091         return TYPE_DISK;
1092 }
1093 EXPORT_SYMBOL(sbc_get_device_type);
1094
1095 sense_reason_t
1096 sbc_execute_unmap(struct se_cmd *cmd,
1097         sense_reason_t (*do_unmap_fn)(struct se_cmd *, void *,
1098                                       sector_t, sector_t),
1099         void *priv)
1100 {
1101         struct se_device *dev = cmd->se_dev;
1102         unsigned char *buf, *ptr = NULL;
1103         sector_t lba;
1104         int size;
1105         u32 range;
1106         sense_reason_t ret = 0;
1107         int dl, bd_dl;
1108
1109         /* We never set ANC_SUP */
1110         if (cmd->t_task_cdb[1])
1111                 return TCM_INVALID_CDB_FIELD;
1112
1113         if (cmd->data_length == 0) {
1114                 target_complete_cmd(cmd, SAM_STAT_GOOD);
1115                 return 0;
1116         }
1117
1118         if (cmd->data_length < 8) {
1119                 pr_warn("UNMAP parameter list length %u too small\n",
1120                         cmd->data_length);
1121                 return TCM_PARAMETER_LIST_LENGTH_ERROR;
1122         }
1123
1124         buf = transport_kmap_data_sg(cmd);
1125         if (!buf)
1126                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1127
1128         dl = get_unaligned_be16(&buf[0]);
1129         bd_dl = get_unaligned_be16(&buf[2]);
1130
1131         size = cmd->data_length - 8;
1132         if (bd_dl > size)
1133                 pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
1134                         cmd->data_length, bd_dl);
1135         else
1136                 size = bd_dl;
1137
1138         if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
1139                 ret = TCM_INVALID_PARAMETER_LIST;
1140                 goto err;
1141         }
1142
1143         /* First UNMAP block descriptor starts at 8 byte offset */
1144         ptr = &buf[8];
1145         pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
1146                 " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
1147
1148         while (size >= 16) {
1149                 lba = get_unaligned_be64(&ptr[0]);
1150                 range = get_unaligned_be32(&ptr[8]);
1151                 pr_debug("UNMAP: Using lba: %llu and range: %u\n",
1152                                  (unsigned long long)lba, range);
1153
1154                 if (range > dev->dev_attrib.max_unmap_lba_count) {
1155                         ret = TCM_INVALID_PARAMETER_LIST;
1156                         goto err;
1157                 }
1158
1159                 if (lba + range > dev->transport->get_blocks(dev) + 1) {
1160                         ret = TCM_ADDRESS_OUT_OF_RANGE;
1161                         goto err;
1162                 }
1163
1164                 ret = do_unmap_fn(cmd, priv, lba, range);
1165                 if (ret)
1166                         goto err;
1167
1168                 ptr += 16;
1169                 size -= 16;
1170         }
1171
1172 err:
1173         transport_kunmap_data_sg(cmd);
1174         if (!ret)
1175                 target_complete_cmd(cmd, GOOD);
1176         return ret;
1177 }
1178 EXPORT_SYMBOL(sbc_execute_unmap);
1179
1180 void
1181 sbc_dif_generate(struct se_cmd *cmd)
1182 {
1183         struct se_device *dev = cmd->se_dev;
1184         struct se_dif_v1_tuple *sdt;
1185         struct scatterlist *dsg, *psg = cmd->t_prot_sg;
1186         sector_t sector = cmd->t_task_lba;
1187         void *daddr, *paddr;
1188         int i, j, offset = 0;
1189
1190         for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {
1191                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1192                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1193
1194                 for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {
1195
1196                         if (offset >= psg->length) {
1197                                 kunmap_atomic(paddr);
1198                                 psg = sg_next(psg);
1199                                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1200                                 offset = 0;
1201                         }
1202
1203                         sdt = paddr + offset;
1204                         sdt->guard_tag = cpu_to_be16(crc_t10dif(daddr + j,
1205                                                 dev->dev_attrib.block_size));
1206                         if (cmd->prot_type == TARGET_DIF_TYPE1_PROT)
1207                                 sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
1208                         sdt->app_tag = 0;
1209
1210                         pr_debug("DIF %s INSERT sector: %llu guard_tag: 0x%04x"
1211                                  " app_tag: 0x%04x ref_tag: %u\n",
1212                                  (cmd->data_direction == DMA_TO_DEVICE) ?
1213                                  "WRITE" : "READ", (unsigned long long)sector,
1214                                  sdt->guard_tag, sdt->app_tag,
1215                                  be32_to_cpu(sdt->ref_tag));
1216
1217                         sector++;
1218                         offset += sizeof(struct se_dif_v1_tuple);
1219                 }
1220
1221                 kunmap_atomic(paddr);
1222                 kunmap_atomic(daddr);
1223         }
1224 }
1225
1226 static sense_reason_t
1227 sbc_dif_v1_verify(struct se_cmd *cmd, struct se_dif_v1_tuple *sdt,
1228                   const void *p, sector_t sector, unsigned int ei_lba)
1229 {
1230         struct se_device *dev = cmd->se_dev;
1231         int block_size = dev->dev_attrib.block_size;
1232         __be16 csum;
1233
1234         if (!(cmd->prot_checks & TARGET_DIF_CHECK_GUARD))
1235                 goto check_ref;
1236
1237         csum = cpu_to_be16(crc_t10dif(p, block_size));
1238
1239         if (sdt->guard_tag != csum) {
1240                 pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1241                         " csum 0x%04x\n", (unsigned long long)sector,
1242                         be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1243                 return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1244         }
1245
1246 check_ref:
1247         if (!(cmd->prot_checks & TARGET_DIF_CHECK_REFTAG))
1248                 return 0;
1249
1250         if (cmd->prot_type == TARGET_DIF_TYPE1_PROT &&
1251             be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1252                 pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1253                        " sector MSB: 0x%08x\n", (unsigned long long)sector,
1254                        be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1255                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1256         }
1257
1258         if (cmd->prot_type == TARGET_DIF_TYPE2_PROT &&
1259             be32_to_cpu(sdt->ref_tag) != ei_lba) {
1260                 pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1261                        " ei_lba: 0x%08x\n", (unsigned long long)sector,
1262                         be32_to_cpu(sdt->ref_tag), ei_lba);
1263                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1264         }
1265
1266         return 0;
1267 }
1268
1269 static void
1270 sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1271                   struct scatterlist *sg, int sg_off)
1272 {
1273         struct se_device *dev = cmd->se_dev;
1274         struct scatterlist *psg;
1275         void *paddr, *addr;
1276         unsigned int i, len, left;
1277         unsigned int offset = sg_off;
1278
1279         if (!sg)
1280                 return;
1281
1282         left = sectors * dev->prot_length;
1283
1284         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1285                 unsigned int psg_len, copied = 0;
1286
1287                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1288                 psg_len = min(left, psg->length);
1289                 while (psg_len) {
1290                         len = min(psg_len, sg->length - offset);
1291                         addr = kmap_atomic(sg_page(sg)) + sg->offset + offset;
1292
1293                         if (read)
1294                                 memcpy(paddr + copied, addr, len);
1295                         else
1296                                 memcpy(addr, paddr + copied, len);
1297
1298                         left -= len;
1299                         offset += len;
1300                         copied += len;
1301                         psg_len -= len;
1302
1303                         if (offset >= sg->length) {
1304                                 sg = sg_next(sg);
1305                                 offset = 0;
1306                         }
1307                         kunmap_atomic(addr);
1308                 }
1309                 kunmap_atomic(paddr);
1310         }
1311 }
1312
1313 sense_reason_t
1314 sbc_dif_verify_write(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1315                      unsigned int ei_lba, struct scatterlist *sg, int sg_off)
1316 {
1317         struct se_device *dev = cmd->se_dev;
1318         struct se_dif_v1_tuple *sdt;
1319         struct scatterlist *dsg, *psg = cmd->t_prot_sg;
1320         sector_t sector = start;
1321         void *daddr, *paddr;
1322         int i, j, offset = 0;
1323         sense_reason_t rc;
1324
1325         for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {
1326                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1327                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1328
1329                 for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {
1330
1331                         if (offset >= psg->length) {
1332                                 kunmap_atomic(paddr);
1333                                 psg = sg_next(psg);
1334                                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1335                                 offset = 0;
1336                         }
1337
1338                         sdt = paddr + offset;
1339
1340                         pr_debug("DIF WRITE sector: %llu guard_tag: 0x%04x"
1341                                  " app_tag: 0x%04x ref_tag: %u\n",
1342                                  (unsigned long long)sector, sdt->guard_tag,
1343                                  sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1344
1345                         rc = sbc_dif_v1_verify(cmd, sdt, daddr + j, sector,
1346                                                ei_lba);
1347                         if (rc) {
1348                                 kunmap_atomic(paddr);
1349                                 kunmap_atomic(daddr);
1350                                 cmd->bad_sector = sector;
1351                                 return rc;
1352                         }
1353
1354                         sector++;
1355                         ei_lba++;
1356                         offset += sizeof(struct se_dif_v1_tuple);
1357                 }
1358
1359                 kunmap_atomic(paddr);
1360                 kunmap_atomic(daddr);
1361         }
1362         if (!sg)
1363                 return 0;
1364
1365         sbc_dif_copy_prot(cmd, sectors, false, sg, sg_off);
1366
1367         return 0;
1368 }
1369 EXPORT_SYMBOL(sbc_dif_verify_write);
1370
1371 static sense_reason_t
1372 __sbc_dif_verify_read(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1373                       unsigned int ei_lba, struct scatterlist *sg, int sg_off)
1374 {
1375         struct se_device *dev = cmd->se_dev;
1376         struct se_dif_v1_tuple *sdt;
1377         struct scatterlist *dsg, *psg = sg;
1378         sector_t sector = start;
1379         void *daddr, *paddr;
1380         int i, j, offset = sg_off;
1381         sense_reason_t rc;
1382
1383         for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {
1384                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1385                 paddr = kmap_atomic(sg_page(psg)) + sg->offset;
1386
1387                 for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {
1388
1389                         if (offset >= psg->length) {
1390                                 kunmap_atomic(paddr);
1391                                 psg = sg_next(psg);
1392                                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1393                                 offset = 0;
1394                         }
1395
1396                         sdt = paddr + offset;
1397
1398                         pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1399                                  " app_tag: 0x%04x ref_tag: %u\n",
1400                                  (unsigned long long)sector, sdt->guard_tag,
1401                                  sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1402
1403                         if (sdt->app_tag == cpu_to_be16(0xffff)) {
1404                                 sector++;
1405                                 offset += sizeof(struct se_dif_v1_tuple);
1406                                 continue;
1407                         }
1408
1409                         rc = sbc_dif_v1_verify(cmd, sdt, daddr + j, sector,
1410                                                ei_lba);
1411                         if (rc) {
1412                                 kunmap_atomic(paddr);
1413                                 kunmap_atomic(daddr);
1414                                 cmd->bad_sector = sector;
1415                                 return rc;
1416                         }
1417
1418                         sector++;
1419                         ei_lba++;
1420                         offset += sizeof(struct se_dif_v1_tuple);
1421                 }
1422
1423                 kunmap_atomic(paddr);
1424                 kunmap_atomic(daddr);
1425         }
1426
1427         return 0;
1428 }
1429
1430 sense_reason_t
1431 sbc_dif_read_strip(struct se_cmd *cmd)
1432 {
1433         struct se_device *dev = cmd->se_dev;
1434         u32 sectors = cmd->prot_length / dev->prot_length;
1435
1436         return __sbc_dif_verify_read(cmd, cmd->t_task_lba, sectors, 0,
1437                                      cmd->t_prot_sg, 0);
1438 }
1439
1440 sense_reason_t
1441 sbc_dif_verify_read(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1442                     unsigned int ei_lba, struct scatterlist *sg, int sg_off)
1443 {
1444         sense_reason_t rc;
1445
1446         rc = __sbc_dif_verify_read(cmd, start, sectors, ei_lba, sg, sg_off);
1447         if (rc)
1448                 return rc;
1449
1450         sbc_dif_copy_prot(cmd, sectors, true, sg, sg_off);
1451         return 0;
1452 }
1453 EXPORT_SYMBOL(sbc_dif_verify_read);