1 /*
2  * Copyright (c) 2004, 2005, 2006 Voltaire, Inc. All rights reserved.
3  * Copyright (c) 2013-2014 Mellanox Technologies. All rights reserved.
4  *
5  * This software is available to you under a choice of one of two
6  * licenses.  You may choose to be licensed under the terms of the GNU
7  * General Public License (GPL) Version 2, available from the file
8  * COPYING in the main directory of this source tree, or the
9  * OpenIB.org BSD license below:
10  *
11  *     Redistribution and use in source and binary forms, with or
12  *     without modification, are permitted provided that the following
13  *     conditions are met:
14  *
15  *	- Redistributions of source code must retain the above
16  *	  copyright notice, this list of conditions and the following
17  *	  disclaimer.
18  *
19  *	- Redistributions in binary form must reproduce the above
20  *	  copyright notice, this list of conditions and the following
21  *	  disclaimer in the documentation and/or other materials
22  *	  provided with the distribution.
23  *
24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31  * SOFTWARE.
32  */
33 #include <linux/module.h>
34 #include <linux/kernel.h>
35 #include <linux/slab.h>
36 #include <linux/mm.h>
37 #include <linux/highmem.h>
38 #include <linux/scatterlist.h>
39 
40 #include "iscsi_iser.h"
41 static
42 int iser_fast_reg_fmr(struct iscsi_iser_task *iser_task,
43 		      struct iser_data_buf *mem,
44 		      struct iser_reg_resources *rsc,
45 		      struct iser_mem_reg *mem_reg);
46 static
47 int iser_fast_reg_mr(struct iscsi_iser_task *iser_task,
48 		     struct iser_data_buf *mem,
49 		     struct iser_reg_resources *rsc,
50 		     struct iser_mem_reg *mem_reg);
51 
52 static const struct iser_reg_ops fastreg_ops = {
53 	.alloc_reg_res	= iser_alloc_fastreg_pool,
54 	.free_reg_res	= iser_free_fastreg_pool,
55 	.reg_mem	= iser_fast_reg_mr,
56 	.unreg_mem	= iser_unreg_mem_fastreg,
57 	.reg_desc_get	= iser_reg_desc_get_fr,
58 	.reg_desc_put	= iser_reg_desc_put_fr,
59 };
60 
61 static const struct iser_reg_ops fmr_ops = {
62 	.alloc_reg_res	= iser_alloc_fmr_pool,
63 	.free_reg_res	= iser_free_fmr_pool,
64 	.reg_mem	= iser_fast_reg_fmr,
65 	.unreg_mem	= iser_unreg_mem_fmr,
66 	.reg_desc_get	= iser_reg_desc_get_fmr,
67 	.reg_desc_put	= iser_reg_desc_put_fmr,
68 };
69 
70 void iser_reg_comp(struct ib_cq *cq, struct ib_wc *wc)
71 {
72 	iser_err_comp(wc, "memreg");
73 }
74 
75 int iser_assign_reg_ops(struct iser_device *device)
76 {
77 	struct ib_device *ib_dev = device->ib_device;
78 
79 	/* Assign function handles  - based on FMR support */
80 	if (ib_dev->ops.alloc_fmr && ib_dev->ops.dealloc_fmr &&
81 	    ib_dev->ops.map_phys_fmr && ib_dev->ops.unmap_fmr) {
82 		iser_info("FMR supported, using FMR for registration\n");
83 		device->reg_ops = &fmr_ops;
84 	} else if (ib_dev->attrs.device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS) {
85 		iser_info("FastReg supported, using FastReg for registration\n");
86 		device->reg_ops = &fastreg_ops;
87 		device->remote_inv_sup = iser_always_reg;
88 	} else {
89 		iser_err("IB device does not support FMRs nor FastRegs, can't register memory\n");
90 		return -1;
91 	}
92 
93 	return 0;
94 }
95 
96 struct iser_fr_desc *
97 iser_reg_desc_get_fr(struct ib_conn *ib_conn)
98 {
99 	struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
100 	struct iser_fr_desc *desc;
101 	unsigned long flags;
102 
103 	spin_lock_irqsave(&fr_pool->lock, flags);
104 	desc = list_first_entry(&fr_pool->list,
105 				struct iser_fr_desc, list);
106 	list_del(&desc->list);
107 	spin_unlock_irqrestore(&fr_pool->lock, flags);
108 
109 	return desc;
110 }
111 
112 void
113 iser_reg_desc_put_fr(struct ib_conn *ib_conn,
114 		     struct iser_fr_desc *desc)
115 {
116 	struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
117 	unsigned long flags;
118 
119 	spin_lock_irqsave(&fr_pool->lock, flags);
120 	list_add(&desc->list, &fr_pool->list);
121 	spin_unlock_irqrestore(&fr_pool->lock, flags);
122 }
123 
124 struct iser_fr_desc *
125 iser_reg_desc_get_fmr(struct ib_conn *ib_conn)
126 {
127 	struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
128 
129 	return list_first_entry(&fr_pool->list,
130 				struct iser_fr_desc, list);
131 }
132 
133 void
134 iser_reg_desc_put_fmr(struct ib_conn *ib_conn,
135 		      struct iser_fr_desc *desc)
136 {
137 }
138 
139 static void iser_data_buf_dump(struct iser_data_buf *data,
140 			       struct ib_device *ibdev)
141 {
142 	struct scatterlist *sg;
143 	int i;
144 
145 	for_each_sg(data->sg, sg, data->dma_nents, i)
146 		iser_dbg("sg[%d] dma_addr:0x%lX page:0x%p "
147 			 "off:0x%x sz:0x%x dma_len:0x%x\n",
148 			 i, (unsigned long)sg_dma_address(sg),
149 			 sg_page(sg), sg->offset, sg->length, sg_dma_len(sg));
150 }
151 
152 static void iser_dump_page_vec(struct iser_page_vec *page_vec)
153 {
154 	int i;
155 
156 	iser_err("page vec npages %d data length %lld\n",
157 		 page_vec->npages, page_vec->fake_mr.length);
158 	for (i = 0; i < page_vec->npages; i++)
159 		iser_err("vec[%d]: %llx\n", i, page_vec->pages[i]);
160 }
161 
162 int iser_dma_map_task_data(struct iscsi_iser_task *iser_task,
163 			    struct iser_data_buf *data,
164 			    enum iser_data_dir iser_dir,
165 			    enum dma_data_direction dma_dir)
166 {
167 	struct ib_device *dev;
168 
169 	iser_task->dir[iser_dir] = 1;
170 	dev = iser_task->iser_conn->ib_conn.device->ib_device;
171 
172 	data->dma_nents = ib_dma_map_sg(dev, data->sg, data->size, dma_dir);
173 	if (unlikely(data->dma_nents == 0)) {
174 		iser_err("dma_map_sg failed!!!\n");
175 		return -EINVAL;
176 	}
177 	return 0;
178 }
179 
180 void iser_dma_unmap_task_data(struct iscsi_iser_task *iser_task,
181 			      struct iser_data_buf *data,
182 			      enum dma_data_direction dir)
183 {
184 	struct ib_device *dev;
185 
186 	dev = iser_task->iser_conn->ib_conn.device->ib_device;
187 	ib_dma_unmap_sg(dev, data->sg, data->size, dir);
188 }
189 
190 static int
191 iser_reg_dma(struct iser_device *device, struct iser_data_buf *mem,
192 	     struct iser_mem_reg *reg)
193 {
194 	struct scatterlist *sg = mem->sg;
195 
196 	reg->sge.lkey = device->pd->local_dma_lkey;
197 	/*
198 	 * FIXME: rework the registration code path to differentiate
199 	 * rkey/lkey use cases
200 	 */
201 
202 	if (device->pd->flags & IB_PD_UNSAFE_GLOBAL_RKEY)
203 		reg->rkey = device->pd->unsafe_global_rkey;
204 	else
205 		reg->rkey = 0;
206 	reg->sge.addr = sg_dma_address(&sg[0]);
207 	reg->sge.length = sg_dma_len(&sg[0]);
208 
209 	iser_dbg("Single DMA entry: lkey=0x%x, rkey=0x%x, addr=0x%llx,"
210 		 " length=0x%x\n", reg->sge.lkey, reg->rkey,
211 		 reg->sge.addr, reg->sge.length);
212 
213 	return 0;
214 }
215 
216 static int iser_set_page(struct ib_mr *mr, u64 addr)
217 {
218 	struct iser_page_vec *page_vec =
219 		container_of(mr, struct iser_page_vec, fake_mr);
220 
221 	page_vec->pages[page_vec->npages++] = addr;
222 
223 	return 0;
224 }
225 
226 static
227 int iser_fast_reg_fmr(struct iscsi_iser_task *iser_task,
228 		      struct iser_data_buf *mem,
229 		      struct iser_reg_resources *rsc,
230 		      struct iser_mem_reg *reg)
231 {
232 	struct ib_conn *ib_conn = &iser_task->iser_conn->ib_conn;
233 	struct iser_device *device = ib_conn->device;
234 	struct iser_page_vec *page_vec = rsc->page_vec;
235 	struct ib_fmr_pool *fmr_pool = rsc->fmr_pool;
236 	struct ib_pool_fmr *fmr;
237 	int ret, plen;
238 
239 	page_vec->npages = 0;
240 	page_vec->fake_mr.page_size = SZ_4K;
241 	plen = ib_sg_to_pages(&page_vec->fake_mr, mem->sg,
242 			      mem->dma_nents, NULL, iser_set_page);
243 	if (unlikely(plen < mem->dma_nents)) {
244 		iser_err("page vec too short to hold this SG\n");
245 		iser_data_buf_dump(mem, device->ib_device);
246 		iser_dump_page_vec(page_vec);
247 		return -EINVAL;
248 	}
249 
250 	fmr  = ib_fmr_pool_map_phys(fmr_pool, page_vec->pages,
251 				    page_vec->npages, page_vec->pages[0]);
252 	if (IS_ERR(fmr)) {
253 		ret = PTR_ERR(fmr);
254 		iser_err("ib_fmr_pool_map_phys failed: %d\n", ret);
255 		return ret;
256 	}
257 
258 	reg->sge.lkey = fmr->fmr->lkey;
259 	reg->rkey = fmr->fmr->rkey;
260 	reg->sge.addr = page_vec->fake_mr.iova;
261 	reg->sge.length = page_vec->fake_mr.length;
262 	reg->mem_h = fmr;
263 
264 	iser_dbg("fmr reg: lkey=0x%x, rkey=0x%x, addr=0x%llx,"
265 		 " length=0x%x\n", reg->sge.lkey, reg->rkey,
266 		 reg->sge.addr, reg->sge.length);
267 
268 	return 0;
269 }
270 
271 /**
272  * Unregister (previosuly registered using FMR) memory.
273  * If memory is non-FMR does nothing.
274  */
275 void iser_unreg_mem_fmr(struct iscsi_iser_task *iser_task,
276 			enum iser_data_dir cmd_dir)
277 {
278 	struct iser_mem_reg *reg = &iser_task->rdma_reg[cmd_dir];
279 
280 	if (!reg->mem_h)
281 		return;
282 
283 	iser_dbg("PHYSICAL Mem.Unregister mem_h %p\n", reg->mem_h);
284 
285 	ib_fmr_pool_unmap((struct ib_pool_fmr *)reg->mem_h);
286 
287 	reg->mem_h = NULL;
288 }
289 
290 void iser_unreg_mem_fastreg(struct iscsi_iser_task *iser_task,
291 			    enum iser_data_dir cmd_dir)
292 {
293 	struct iser_device *device = iser_task->iser_conn->ib_conn.device;
294 	struct iser_mem_reg *reg = &iser_task->rdma_reg[cmd_dir];
295 	struct iser_fr_desc *desc;
296 	struct ib_mr_status mr_status;
297 
298 	desc = reg->mem_h;
299 	if (!desc)
300 		return;
301 
302 	/*
303 	 * The signature MR cannot be invalidated and reused without checking.
304 	 * libiscsi calls the check_protection transport handler only if
305 	 * SCSI-Response is received. And the signature MR is not checked if
306 	 * the task is completed for some other reason like a timeout or error
307 	 * handling. That's why we must check the signature MR here before
308 	 * putting it to the free pool.
309 	 */
310 	if (unlikely(desc->sig_protected)) {
311 		desc->sig_protected = false;
312 		ib_check_mr_status(desc->rsc.sig_mr, IB_MR_CHECK_SIG_STATUS,
313 				   &mr_status);
314 	}
315 	device->reg_ops->reg_desc_put(&iser_task->iser_conn->ib_conn, desc);
316 	reg->mem_h = NULL;
317 }
318 
319 static void
320 iser_set_dif_domain(struct scsi_cmnd *sc, struct ib_sig_domain *domain)
321 {
322 	domain->sig_type = IB_SIG_TYPE_T10_DIF;
323 	domain->sig.dif.pi_interval = scsi_prot_interval(sc);
324 	domain->sig.dif.ref_tag = t10_pi_ref_tag(sc->request);
325 	/*
326 	 * At the moment we hard code those, but in the future
327 	 * we will take them from sc.
328 	 */
329 	domain->sig.dif.apptag_check_mask = 0xffff;
330 	domain->sig.dif.app_escape = true;
331 	domain->sig.dif.ref_escape = true;
332 	if (sc->prot_flags & SCSI_PROT_REF_INCREMENT)
333 		domain->sig.dif.ref_remap = true;
334 };
335 
336 static int
337 iser_set_sig_attrs(struct scsi_cmnd *sc, struct ib_sig_attrs *sig_attrs)
338 {
339 	switch (scsi_get_prot_op(sc)) {
340 	case SCSI_PROT_WRITE_INSERT:
341 	case SCSI_PROT_READ_STRIP:
342 		sig_attrs->mem.sig_type = IB_SIG_TYPE_NONE;
343 		iser_set_dif_domain(sc, &sig_attrs->wire);
344 		sig_attrs->wire.sig.dif.bg_type = IB_T10DIF_CRC;
345 		break;
346 	case SCSI_PROT_READ_INSERT:
347 	case SCSI_PROT_WRITE_STRIP:
348 		sig_attrs->wire.sig_type = IB_SIG_TYPE_NONE;
349 		iser_set_dif_domain(sc, &sig_attrs->mem);
350 		sig_attrs->mem.sig.dif.bg_type = sc->prot_flags & SCSI_PROT_IP_CHECKSUM ?
351 						IB_T10DIF_CSUM : IB_T10DIF_CRC;
352 		break;
353 	case SCSI_PROT_READ_PASS:
354 	case SCSI_PROT_WRITE_PASS:
355 		iser_set_dif_domain(sc, &sig_attrs->wire);
356 		sig_attrs->wire.sig.dif.bg_type = IB_T10DIF_CRC;
357 		iser_set_dif_domain(sc, &sig_attrs->mem);
358 		sig_attrs->mem.sig.dif.bg_type = sc->prot_flags & SCSI_PROT_IP_CHECKSUM ?
359 						IB_T10DIF_CSUM : IB_T10DIF_CRC;
360 		break;
361 	default:
362 		iser_err("Unsupported PI operation %d\n",
363 			 scsi_get_prot_op(sc));
364 		return -EINVAL;
365 	}
366 
367 	return 0;
368 }
369 
370 static inline void
371 iser_set_prot_checks(struct scsi_cmnd *sc, u8 *mask)
372 {
373 	*mask = 0;
374 	if (sc->prot_flags & SCSI_PROT_REF_CHECK)
375 		*mask |= IB_SIG_CHECK_REFTAG;
376 	if (sc->prot_flags & SCSI_PROT_GUARD_CHECK)
377 		*mask |= IB_SIG_CHECK_GUARD;
378 }
379 
380 static inline void
381 iser_inv_rkey(struct ib_send_wr *inv_wr,
382 	      struct ib_mr *mr,
383 	      struct ib_cqe *cqe,
384 	      struct ib_send_wr *next_wr)
385 {
386 	inv_wr->opcode = IB_WR_LOCAL_INV;
387 	inv_wr->wr_cqe = cqe;
388 	inv_wr->ex.invalidate_rkey = mr->rkey;
389 	inv_wr->send_flags = 0;
390 	inv_wr->num_sge = 0;
391 	inv_wr->next = next_wr;
392 }
393 
394 static int
395 iser_reg_sig_mr(struct iscsi_iser_task *iser_task,
396 		struct iser_data_buf *mem,
397 		struct iser_data_buf *sig_mem,
398 		struct iser_reg_resources *rsc,
399 		struct iser_mem_reg *sig_reg)
400 {
401 	struct iser_tx_desc *tx_desc = &iser_task->desc;
402 	struct ib_cqe *cqe = &iser_task->iser_conn->ib_conn.reg_cqe;
403 	struct ib_mr *mr = rsc->sig_mr;
404 	struct ib_sig_attrs *sig_attrs = mr->sig_attrs;
405 	struct ib_reg_wr *wr = &tx_desc->reg_wr;
406 	int ret;
407 
408 	memset(sig_attrs, 0, sizeof(*sig_attrs));
409 	ret = iser_set_sig_attrs(iser_task->sc, sig_attrs);
410 	if (ret)
411 		goto err;
412 
413 	iser_set_prot_checks(iser_task->sc, &sig_attrs->check_mask);
414 
415 	if (rsc->mr_valid)
416 		iser_inv_rkey(&tx_desc->inv_wr, mr, cqe, &wr->wr);
417 
418 	ib_update_fast_reg_key(mr, ib_inc_rkey(mr->rkey));
419 
420 	ret = ib_map_mr_sg_pi(mr, mem->sg, mem->dma_nents, NULL,
421 			      sig_mem->sg, sig_mem->dma_nents, NULL, SZ_4K);
422 	if (unlikely(ret)) {
423 		iser_err("failed to map PI sg (%d)\n",
424 			 mem->dma_nents + sig_mem->dma_nents);
425 		goto err;
426 	}
427 
428 	memset(wr, 0, sizeof(*wr));
429 	wr->wr.next = &tx_desc->send_wr;
430 	wr->wr.opcode = IB_WR_REG_MR_INTEGRITY;
431 	wr->wr.wr_cqe = cqe;
432 	wr->wr.num_sge = 0;
433 	wr->wr.send_flags = 0;
434 	wr->mr = mr;
435 	wr->key = mr->rkey;
436 	wr->access = IB_ACCESS_LOCAL_WRITE |
437 		     IB_ACCESS_REMOTE_READ |
438 		     IB_ACCESS_REMOTE_WRITE;
439 	rsc->mr_valid = 1;
440 
441 	sig_reg->sge.lkey = mr->lkey;
442 	sig_reg->rkey = mr->rkey;
443 	sig_reg->sge.addr = mr->iova;
444 	sig_reg->sge.length = mr->length;
445 
446 	iser_dbg("lkey=0x%x rkey=0x%x addr=0x%llx length=%u\n",
447 		 sig_reg->sge.lkey, sig_reg->rkey, sig_reg->sge.addr,
448 		 sig_reg->sge.length);
449 err:
450 	return ret;
451 }
452 
453 static int iser_fast_reg_mr(struct iscsi_iser_task *iser_task,
454 			    struct iser_data_buf *mem,
455 			    struct iser_reg_resources *rsc,
456 			    struct iser_mem_reg *reg)
457 {
458 	struct iser_tx_desc *tx_desc = &iser_task->desc;
459 	struct ib_cqe *cqe = &iser_task->iser_conn->ib_conn.reg_cqe;
460 	struct ib_mr *mr = rsc->mr;
461 	struct ib_reg_wr *wr = &tx_desc->reg_wr;
462 	int n;
463 
464 	if (rsc->mr_valid)
465 		iser_inv_rkey(&tx_desc->inv_wr, mr, cqe, &wr->wr);
466 
467 	ib_update_fast_reg_key(mr, ib_inc_rkey(mr->rkey));
468 
469 	n = ib_map_mr_sg(mr, mem->sg, mem->dma_nents, NULL, SZ_4K);
470 	if (unlikely(n != mem->dma_nents)) {
471 		iser_err("failed to map sg (%d/%d)\n",
472 			 n, mem->dma_nents);
473 		return n < 0 ? n : -EINVAL;
474 	}
475 
476 	wr->wr.next = &tx_desc->send_wr;
477 	wr->wr.opcode = IB_WR_REG_MR;
478 	wr->wr.wr_cqe = cqe;
479 	wr->wr.send_flags = 0;
480 	wr->wr.num_sge = 0;
481 	wr->mr = mr;
482 	wr->key = mr->rkey;
483 	wr->access = IB_ACCESS_LOCAL_WRITE  |
484 		     IB_ACCESS_REMOTE_WRITE |
485 		     IB_ACCESS_REMOTE_READ;
486 
487 	rsc->mr_valid = 1;
488 
489 	reg->sge.lkey = mr->lkey;
490 	reg->rkey = mr->rkey;
491 	reg->sge.addr = mr->iova;
492 	reg->sge.length = mr->length;
493 
494 	iser_dbg("lkey=0x%x rkey=0x%x addr=0x%llx length=0x%x\n",
495 		 reg->sge.lkey, reg->rkey, reg->sge.addr, reg->sge.length);
496 
497 	return 0;
498 }
499 
500 static int
501 iser_reg_data_sg(struct iscsi_iser_task *task,
502 		 struct iser_data_buf *mem,
503 		 struct iser_fr_desc *desc,
504 		 bool use_dma_key,
505 		 struct iser_mem_reg *reg)
506 {
507 	struct iser_device *device = task->iser_conn->ib_conn.device;
508 
509 	if (use_dma_key)
510 		return iser_reg_dma(device, mem, reg);
511 
512 	return device->reg_ops->reg_mem(task, mem, &desc->rsc, reg);
513 }
514 
515 int iser_reg_rdma_mem(struct iscsi_iser_task *task,
516 		      enum iser_data_dir dir,
517 		      bool all_imm)
518 {
519 	struct ib_conn *ib_conn = &task->iser_conn->ib_conn;
520 	struct iser_device *device = ib_conn->device;
521 	struct iser_data_buf *mem = &task->data[dir];
522 	struct iser_mem_reg *reg = &task->rdma_reg[dir];
523 	struct iser_fr_desc *desc = NULL;
524 	bool use_dma_key;
525 	int err;
526 
527 	use_dma_key = mem->dma_nents == 1 && (all_imm || !iser_always_reg) &&
528 		      scsi_get_prot_op(task->sc) == SCSI_PROT_NORMAL;
529 
530 	if (!use_dma_key) {
531 		desc = device->reg_ops->reg_desc_get(ib_conn);
532 		reg->mem_h = desc;
533 	}
534 
535 	if (scsi_get_prot_op(task->sc) == SCSI_PROT_NORMAL) {
536 		err = iser_reg_data_sg(task, mem, desc, use_dma_key, reg);
537 		if (unlikely(err))
538 			goto err_reg;
539 	} else {
540 		err = iser_reg_sig_mr(task, mem, &task->prot[dir],
541 				      &desc->rsc, reg);
542 		if (unlikely(err))
543 			goto err_reg;
544 
545 		desc->sig_protected = true;
546 	}
547 
548 	return 0;
549 
550 err_reg:
551 	if (desc)
552 		device->reg_ops->reg_desc_put(ib_conn, desc);
553 
554 	return err;
555 }
556 
557 void iser_unreg_rdma_mem(struct iscsi_iser_task *task,
558 			 enum iser_data_dir dir)
559 {
560 	struct iser_device *device = task->iser_conn->ib_conn.device;
561 
562 	device->reg_ops->unreg_mem(task, dir);
563 }
564