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 
42 void iser_reg_comp(struct ib_cq *cq, struct ib_wc *wc)
43 {
44 	iser_err_comp(wc, "memreg");
45 }
46 
47 static struct iser_fr_desc *
48 iser_reg_desc_get_fr(struct ib_conn *ib_conn)
49 {
50 	struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
51 	struct iser_fr_desc *desc;
52 	unsigned long flags;
53 
54 	spin_lock_irqsave(&fr_pool->lock, flags);
55 	desc = list_first_entry(&fr_pool->list,
56 				struct iser_fr_desc, list);
57 	list_del(&desc->list);
58 	spin_unlock_irqrestore(&fr_pool->lock, flags);
59 
60 	return desc;
61 }
62 
63 static void
64 iser_reg_desc_put_fr(struct ib_conn *ib_conn,
65 		     struct iser_fr_desc *desc)
66 {
67 	struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
68 	unsigned long flags;
69 
70 	spin_lock_irqsave(&fr_pool->lock, flags);
71 	list_add(&desc->list, &fr_pool->list);
72 	spin_unlock_irqrestore(&fr_pool->lock, flags);
73 }
74 
75 int iser_dma_map_task_data(struct iscsi_iser_task *iser_task,
76 			    struct iser_data_buf *data,
77 			    enum iser_data_dir iser_dir,
78 			    enum dma_data_direction dma_dir)
79 {
80 	struct ib_device *dev;
81 
82 	iser_task->dir[iser_dir] = 1;
83 	dev = iser_task->iser_conn->ib_conn.device->ib_device;
84 
85 	data->dma_nents = ib_dma_map_sg(dev, data->sg, data->size, dma_dir);
86 	if (unlikely(data->dma_nents == 0)) {
87 		iser_err("dma_map_sg failed!!!\n");
88 		return -EINVAL;
89 	}
90 	return 0;
91 }
92 
93 void iser_dma_unmap_task_data(struct iscsi_iser_task *iser_task,
94 			      struct iser_data_buf *data,
95 			      enum dma_data_direction dir)
96 {
97 	struct ib_device *dev;
98 
99 	dev = iser_task->iser_conn->ib_conn.device->ib_device;
100 	ib_dma_unmap_sg(dev, data->sg, data->size, dir);
101 }
102 
103 static int
104 iser_reg_dma(struct iser_device *device, struct iser_data_buf *mem,
105 	     struct iser_mem_reg *reg)
106 {
107 	struct scatterlist *sg = mem->sg;
108 
109 	reg->sge.lkey = device->pd->local_dma_lkey;
110 	/*
111 	 * FIXME: rework the registration code path to differentiate
112 	 * rkey/lkey use cases
113 	 */
114 
115 	if (device->pd->flags & IB_PD_UNSAFE_GLOBAL_RKEY)
116 		reg->rkey = device->pd->unsafe_global_rkey;
117 	else
118 		reg->rkey = 0;
119 	reg->sge.addr = sg_dma_address(&sg[0]);
120 	reg->sge.length = sg_dma_len(&sg[0]);
121 
122 	iser_dbg("Single DMA entry: lkey=0x%x, rkey=0x%x, addr=0x%llx,"
123 		 " length=0x%x\n", reg->sge.lkey, reg->rkey,
124 		 reg->sge.addr, reg->sge.length);
125 
126 	return 0;
127 }
128 
129 void iser_unreg_mem_fastreg(struct iscsi_iser_task *iser_task,
130 			    enum iser_data_dir cmd_dir)
131 {
132 	struct iser_mem_reg *reg = &iser_task->rdma_reg[cmd_dir];
133 	struct iser_fr_desc *desc;
134 	struct ib_mr_status mr_status;
135 
136 	desc = reg->mem_h;
137 	if (!desc)
138 		return;
139 
140 	/*
141 	 * The signature MR cannot be invalidated and reused without checking.
142 	 * libiscsi calls the check_protection transport handler only if
143 	 * SCSI-Response is received. And the signature MR is not checked if
144 	 * the task is completed for some other reason like a timeout or error
145 	 * handling. That's why we must check the signature MR here before
146 	 * putting it to the free pool.
147 	 */
148 	if (unlikely(desc->sig_protected)) {
149 		desc->sig_protected = false;
150 		ib_check_mr_status(desc->rsc.sig_mr, IB_MR_CHECK_SIG_STATUS,
151 				   &mr_status);
152 	}
153 	iser_reg_desc_put_fr(&iser_task->iser_conn->ib_conn, reg->mem_h);
154 	reg->mem_h = NULL;
155 }
156 
157 static void
158 iser_set_dif_domain(struct scsi_cmnd *sc, struct ib_sig_domain *domain)
159 {
160 	domain->sig_type = IB_SIG_TYPE_T10_DIF;
161 	domain->sig.dif.pi_interval = scsi_prot_interval(sc);
162 	domain->sig.dif.ref_tag = t10_pi_ref_tag(scsi_cmd_to_rq(sc));
163 	/*
164 	 * At the moment we hard code those, but in the future
165 	 * we will take them from sc.
166 	 */
167 	domain->sig.dif.apptag_check_mask = 0xffff;
168 	domain->sig.dif.app_escape = true;
169 	domain->sig.dif.ref_escape = true;
170 	if (sc->prot_flags & SCSI_PROT_REF_INCREMENT)
171 		domain->sig.dif.ref_remap = true;
172 }
173 
174 static int
175 iser_set_sig_attrs(struct scsi_cmnd *sc, struct ib_sig_attrs *sig_attrs)
176 {
177 	switch (scsi_get_prot_op(sc)) {
178 	case SCSI_PROT_WRITE_INSERT:
179 	case SCSI_PROT_READ_STRIP:
180 		sig_attrs->mem.sig_type = IB_SIG_TYPE_NONE;
181 		iser_set_dif_domain(sc, &sig_attrs->wire);
182 		sig_attrs->wire.sig.dif.bg_type = IB_T10DIF_CRC;
183 		break;
184 	case SCSI_PROT_READ_INSERT:
185 	case SCSI_PROT_WRITE_STRIP:
186 		sig_attrs->wire.sig_type = IB_SIG_TYPE_NONE;
187 		iser_set_dif_domain(sc, &sig_attrs->mem);
188 		sig_attrs->mem.sig.dif.bg_type = sc->prot_flags & SCSI_PROT_IP_CHECKSUM ?
189 						IB_T10DIF_CSUM : IB_T10DIF_CRC;
190 		break;
191 	case SCSI_PROT_READ_PASS:
192 	case SCSI_PROT_WRITE_PASS:
193 		iser_set_dif_domain(sc, &sig_attrs->wire);
194 		sig_attrs->wire.sig.dif.bg_type = IB_T10DIF_CRC;
195 		iser_set_dif_domain(sc, &sig_attrs->mem);
196 		sig_attrs->mem.sig.dif.bg_type = sc->prot_flags & SCSI_PROT_IP_CHECKSUM ?
197 						IB_T10DIF_CSUM : IB_T10DIF_CRC;
198 		break;
199 	default:
200 		iser_err("Unsupported PI operation %d\n",
201 			 scsi_get_prot_op(sc));
202 		return -EINVAL;
203 	}
204 
205 	return 0;
206 }
207 
208 static inline void
209 iser_set_prot_checks(struct scsi_cmnd *sc, u8 *mask)
210 {
211 	*mask = 0;
212 	if (sc->prot_flags & SCSI_PROT_REF_CHECK)
213 		*mask |= IB_SIG_CHECK_REFTAG;
214 	if (sc->prot_flags & SCSI_PROT_GUARD_CHECK)
215 		*mask |= IB_SIG_CHECK_GUARD;
216 }
217 
218 static inline void
219 iser_inv_rkey(struct ib_send_wr *inv_wr,
220 	      struct ib_mr *mr,
221 	      struct ib_cqe *cqe,
222 	      struct ib_send_wr *next_wr)
223 {
224 	inv_wr->opcode = IB_WR_LOCAL_INV;
225 	inv_wr->wr_cqe = cqe;
226 	inv_wr->ex.invalidate_rkey = mr->rkey;
227 	inv_wr->send_flags = 0;
228 	inv_wr->num_sge = 0;
229 	inv_wr->next = next_wr;
230 }
231 
232 static int
233 iser_reg_sig_mr(struct iscsi_iser_task *iser_task,
234 		struct iser_data_buf *mem,
235 		struct iser_data_buf *sig_mem,
236 		struct iser_reg_resources *rsc,
237 		struct iser_mem_reg *sig_reg)
238 {
239 	struct iser_tx_desc *tx_desc = &iser_task->desc;
240 	struct ib_cqe *cqe = &iser_task->iser_conn->ib_conn.reg_cqe;
241 	struct ib_mr *mr = rsc->sig_mr;
242 	struct ib_sig_attrs *sig_attrs = mr->sig_attrs;
243 	struct ib_reg_wr *wr = &tx_desc->reg_wr;
244 	int ret;
245 
246 	memset(sig_attrs, 0, sizeof(*sig_attrs));
247 	ret = iser_set_sig_attrs(iser_task->sc, sig_attrs);
248 	if (ret)
249 		goto err;
250 
251 	iser_set_prot_checks(iser_task->sc, &sig_attrs->check_mask);
252 
253 	if (rsc->mr_valid)
254 		iser_inv_rkey(&tx_desc->inv_wr, mr, cqe, &wr->wr);
255 
256 	ib_update_fast_reg_key(mr, ib_inc_rkey(mr->rkey));
257 
258 	ret = ib_map_mr_sg_pi(mr, mem->sg, mem->dma_nents, NULL,
259 			      sig_mem->sg, sig_mem->dma_nents, NULL, SZ_4K);
260 	if (unlikely(ret)) {
261 		iser_err("failed to map PI sg (%d)\n",
262 			 mem->dma_nents + sig_mem->dma_nents);
263 		goto err;
264 	}
265 
266 	memset(wr, 0, sizeof(*wr));
267 	wr->wr.next = &tx_desc->send_wr;
268 	wr->wr.opcode = IB_WR_REG_MR_INTEGRITY;
269 	wr->wr.wr_cqe = cqe;
270 	wr->wr.num_sge = 0;
271 	wr->wr.send_flags = 0;
272 	wr->mr = mr;
273 	wr->key = mr->rkey;
274 	wr->access = IB_ACCESS_LOCAL_WRITE |
275 		     IB_ACCESS_REMOTE_READ |
276 		     IB_ACCESS_REMOTE_WRITE;
277 	rsc->mr_valid = 1;
278 
279 	sig_reg->sge.lkey = mr->lkey;
280 	sig_reg->rkey = mr->rkey;
281 	sig_reg->sge.addr = mr->iova;
282 	sig_reg->sge.length = mr->length;
283 
284 	iser_dbg("lkey=0x%x rkey=0x%x addr=0x%llx length=%u\n",
285 		 sig_reg->sge.lkey, sig_reg->rkey, sig_reg->sge.addr,
286 		 sig_reg->sge.length);
287 err:
288 	return ret;
289 }
290 
291 static int iser_fast_reg_mr(struct iscsi_iser_task *iser_task,
292 			    struct iser_data_buf *mem,
293 			    struct iser_reg_resources *rsc,
294 			    struct iser_mem_reg *reg)
295 {
296 	struct iser_tx_desc *tx_desc = &iser_task->desc;
297 	struct ib_cqe *cqe = &iser_task->iser_conn->ib_conn.reg_cqe;
298 	struct ib_mr *mr = rsc->mr;
299 	struct ib_reg_wr *wr = &tx_desc->reg_wr;
300 	int n;
301 
302 	if (rsc->mr_valid)
303 		iser_inv_rkey(&tx_desc->inv_wr, mr, cqe, &wr->wr);
304 
305 	ib_update_fast_reg_key(mr, ib_inc_rkey(mr->rkey));
306 
307 	n = ib_map_mr_sg(mr, mem->sg, mem->dma_nents, NULL, SZ_4K);
308 	if (unlikely(n != mem->dma_nents)) {
309 		iser_err("failed to map sg (%d/%d)\n",
310 			 n, mem->dma_nents);
311 		return n < 0 ? n : -EINVAL;
312 	}
313 
314 	wr->wr.next = &tx_desc->send_wr;
315 	wr->wr.opcode = IB_WR_REG_MR;
316 	wr->wr.wr_cqe = cqe;
317 	wr->wr.send_flags = 0;
318 	wr->wr.num_sge = 0;
319 	wr->mr = mr;
320 	wr->key = mr->rkey;
321 	wr->access = IB_ACCESS_LOCAL_WRITE  |
322 		     IB_ACCESS_REMOTE_WRITE |
323 		     IB_ACCESS_REMOTE_READ;
324 
325 	rsc->mr_valid = 1;
326 
327 	reg->sge.lkey = mr->lkey;
328 	reg->rkey = mr->rkey;
329 	reg->sge.addr = mr->iova;
330 	reg->sge.length = mr->length;
331 
332 	iser_dbg("lkey=0x%x rkey=0x%x addr=0x%llx length=0x%x\n",
333 		 reg->sge.lkey, reg->rkey, reg->sge.addr, reg->sge.length);
334 
335 	return 0;
336 }
337 
338 static int
339 iser_reg_data_sg(struct iscsi_iser_task *task,
340 		 struct iser_data_buf *mem,
341 		 struct iser_fr_desc *desc,
342 		 bool use_dma_key,
343 		 struct iser_mem_reg *reg)
344 {
345 	struct iser_device *device = task->iser_conn->ib_conn.device;
346 
347 	if (use_dma_key)
348 		return iser_reg_dma(device, mem, reg);
349 
350 	return iser_fast_reg_mr(task, mem, &desc->rsc, reg);
351 }
352 
353 int iser_reg_mem_fastreg(struct iscsi_iser_task *task,
354 			 enum iser_data_dir dir,
355 			 bool all_imm)
356 {
357 	struct ib_conn *ib_conn = &task->iser_conn->ib_conn;
358 	struct iser_data_buf *mem = &task->data[dir];
359 	struct iser_mem_reg *reg = &task->rdma_reg[dir];
360 	struct iser_fr_desc *desc = NULL;
361 	bool use_dma_key;
362 	int err;
363 
364 	use_dma_key = mem->dma_nents == 1 && (all_imm || !iser_always_reg) &&
365 		      scsi_get_prot_op(task->sc) == SCSI_PROT_NORMAL;
366 
367 	if (!use_dma_key) {
368 		desc = iser_reg_desc_get_fr(ib_conn);
369 		reg->mem_h = desc;
370 	}
371 
372 	if (scsi_get_prot_op(task->sc) == SCSI_PROT_NORMAL) {
373 		err = iser_reg_data_sg(task, mem, desc, use_dma_key, reg);
374 		if (unlikely(err))
375 			goto err_reg;
376 	} else {
377 		err = iser_reg_sig_mr(task, mem, &task->prot[dir],
378 				      &desc->rsc, reg);
379 		if (unlikely(err))
380 			goto err_reg;
381 
382 		desc->sig_protected = true;
383 	}
384 
385 	return 0;
386 
387 err_reg:
388 	if (desc)
389 		iser_reg_desc_put_fr(ib_conn, desc);
390 
391 	return err;
392 }
393