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