xref: /linux/drivers/infiniband/ulp/iser/iser_memory.c (revision fe33c0fbed75dd464747c0faaedf94c7d8eb4101)
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/kernel.h>
34 #include <linux/slab.h>
35 #include <linux/mm.h>
36 #include <linux/highmem.h>
37 #include <linux/scatterlist.h>
38 
39 #include "iscsi_iser.h"
40 
41 void iser_reg_comp(struct ib_cq *cq, struct ib_wc *wc)
42 {
43 	iser_err_comp(wc, "memreg");
44 }
45 
46 static struct iser_fr_desc *iser_reg_desc_get_fr(struct ib_conn *ib_conn)
47 {
48 	struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
49 	struct iser_fr_desc *desc;
50 	unsigned long flags;
51 
52 	spin_lock_irqsave(&fr_pool->lock, flags);
53 	desc = list_first_entry(&fr_pool->list,
54 				struct iser_fr_desc, list);
55 	list_del(&desc->list);
56 	spin_unlock_irqrestore(&fr_pool->lock, flags);
57 
58 	return desc;
59 }
60 
61 static void iser_reg_desc_put_fr(struct ib_conn *ib_conn,
62 				 struct iser_fr_desc *desc)
63 {
64 	struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
65 	unsigned long flags;
66 
67 	spin_lock_irqsave(&fr_pool->lock, flags);
68 	list_add(&desc->list, &fr_pool->list);
69 	spin_unlock_irqrestore(&fr_pool->lock, flags);
70 }
71 
72 int iser_dma_map_task_data(struct iscsi_iser_task *iser_task,
73 			   enum iser_data_dir iser_dir,
74 			   enum dma_data_direction dma_dir)
75 {
76 	struct iser_data_buf *data = &iser_task->data[iser_dir];
77 	struct ib_device *dev;
78 
79 	iser_task->dir[iser_dir] = 1;
80 	dev = iser_task->iser_conn->ib_conn.device->ib_device;
81 
82 	data->dma_nents = ib_dma_map_sg(dev, data->sg, data->size, dma_dir);
83 	if (unlikely(data->dma_nents == 0)) {
84 		iser_err("dma_map_sg failed!!!\n");
85 		return -EINVAL;
86 	}
87 
88 	if (scsi_prot_sg_count(iser_task->sc)) {
89 		struct iser_data_buf *pdata = &iser_task->prot[iser_dir];
90 
91 		pdata->dma_nents = ib_dma_map_sg(dev, pdata->sg, pdata->size, dma_dir);
92 		if (unlikely(pdata->dma_nents == 0)) {
93 			iser_err("protection dma_map_sg failed!!!\n");
94 			goto out_unmap;
95 		}
96 	}
97 
98 	return 0;
99 
100 out_unmap:
101 	ib_dma_unmap_sg(dev, data->sg, data->size, dma_dir);
102 	return -EINVAL;
103 }
104 
105 
106 void iser_dma_unmap_task_data(struct iscsi_iser_task *iser_task,
107 			      enum iser_data_dir iser_dir,
108 			      enum dma_data_direction dma_dir)
109 {
110 	struct iser_data_buf *data = &iser_task->data[iser_dir];
111 	struct ib_device *dev;
112 
113 	dev = iser_task->iser_conn->ib_conn.device->ib_device;
114 	ib_dma_unmap_sg(dev, data->sg, data->size, dma_dir);
115 
116 	if (scsi_prot_sg_count(iser_task->sc)) {
117 		struct iser_data_buf *pdata = &iser_task->prot[iser_dir];
118 
119 		ib_dma_unmap_sg(dev, pdata->sg, pdata->size, dma_dir);
120 	}
121 }
122 
123 static int iser_reg_dma(struct iser_device *device, struct iser_data_buf *mem,
124 			struct iser_mem_reg *reg)
125 {
126 	struct scatterlist *sg = mem->sg;
127 
128 	reg->sge.lkey = device->pd->local_dma_lkey;
129 	/*
130 	 * FIXME: rework the registration code path to differentiate
131 	 * rkey/lkey use cases
132 	 */
133 
134 	if (device->pd->flags & IB_PD_UNSAFE_GLOBAL_RKEY)
135 		reg->rkey = device->pd->unsafe_global_rkey;
136 	else
137 		reg->rkey = 0;
138 	reg->sge.addr = sg_dma_address(&sg[0]);
139 	reg->sge.length = sg_dma_len(&sg[0]);
140 
141 	iser_dbg("Single DMA entry: lkey=0x%x, rkey=0x%x, addr=0x%llx,"
142 		 " length=0x%x\n", reg->sge.lkey, reg->rkey,
143 		 reg->sge.addr, reg->sge.length);
144 
145 	return 0;
146 }
147 
148 void iser_unreg_mem_fastreg(struct iscsi_iser_task *iser_task,
149 			    enum iser_data_dir cmd_dir)
150 {
151 	struct iser_mem_reg *reg = &iser_task->rdma_reg[cmd_dir];
152 	struct iser_fr_desc *desc;
153 	struct ib_mr_status mr_status;
154 
155 	desc = reg->desc;
156 	if (!desc)
157 		return;
158 
159 	/*
160 	 * The signature MR cannot be invalidated and reused without checking.
161 	 * libiscsi calls the check_protection transport handler only if
162 	 * SCSI-Response is received. And the signature MR is not checked if
163 	 * the task is completed for some other reason like a timeout or error
164 	 * handling. That's why we must check the signature MR here before
165 	 * putting it to the free pool.
166 	 */
167 	if (unlikely(desc->sig_protected)) {
168 		desc->sig_protected = false;
169 		ib_check_mr_status(desc->rsc.sig_mr, IB_MR_CHECK_SIG_STATUS,
170 				   &mr_status);
171 	}
172 	iser_reg_desc_put_fr(&iser_task->iser_conn->ib_conn, reg->desc);
173 	reg->desc = NULL;
174 }
175 
176 static void iser_set_dif_domain(struct scsi_cmnd *sc,
177 				struct ib_sig_domain *domain)
178 {
179 	domain->sig_type = IB_SIG_TYPE_T10_DIF;
180 	domain->sig.dif.pi_interval = scsi_prot_interval(sc);
181 	domain->sig.dif.ref_tag = t10_pi_ref_tag(scsi_cmd_to_rq(sc));
182 	/*
183 	 * At the moment we hard code those, but in the future
184 	 * we will take them from sc.
185 	 */
186 	domain->sig.dif.apptag_check_mask = 0xffff;
187 	domain->sig.dif.app_escape = true;
188 	domain->sig.dif.ref_escape = true;
189 	if (sc->prot_flags & SCSI_PROT_REF_INCREMENT)
190 		domain->sig.dif.ref_remap = true;
191 }
192 
193 static int iser_set_sig_attrs(struct scsi_cmnd *sc,
194 			      struct ib_sig_attrs *sig_attrs)
195 {
196 	switch (scsi_get_prot_op(sc)) {
197 	case SCSI_PROT_WRITE_INSERT:
198 	case SCSI_PROT_READ_STRIP:
199 		sig_attrs->mem.sig_type = IB_SIG_TYPE_NONE;
200 		iser_set_dif_domain(sc, &sig_attrs->wire);
201 		sig_attrs->wire.sig.dif.bg_type = IB_T10DIF_CRC;
202 		break;
203 	case SCSI_PROT_READ_INSERT:
204 	case SCSI_PROT_WRITE_STRIP:
205 		sig_attrs->wire.sig_type = IB_SIG_TYPE_NONE;
206 		iser_set_dif_domain(sc, &sig_attrs->mem);
207 		sig_attrs->mem.sig.dif.bg_type = sc->prot_flags & SCSI_PROT_IP_CHECKSUM ?
208 						IB_T10DIF_CSUM : IB_T10DIF_CRC;
209 		break;
210 	case SCSI_PROT_READ_PASS:
211 	case SCSI_PROT_WRITE_PASS:
212 		iser_set_dif_domain(sc, &sig_attrs->wire);
213 		sig_attrs->wire.sig.dif.bg_type = IB_T10DIF_CRC;
214 		iser_set_dif_domain(sc, &sig_attrs->mem);
215 		sig_attrs->mem.sig.dif.bg_type = sc->prot_flags & SCSI_PROT_IP_CHECKSUM ?
216 						IB_T10DIF_CSUM : IB_T10DIF_CRC;
217 		break;
218 	default:
219 		iser_err("Unsupported PI operation %d\n",
220 			 scsi_get_prot_op(sc));
221 		return -EINVAL;
222 	}
223 
224 	return 0;
225 }
226 
227 static inline void iser_set_prot_checks(struct scsi_cmnd *sc, u8 *mask)
228 {
229 	*mask = 0;
230 	if (sc->prot_flags & SCSI_PROT_REF_CHECK)
231 		*mask |= IB_SIG_CHECK_REFTAG;
232 	if (sc->prot_flags & SCSI_PROT_GUARD_CHECK)
233 		*mask |= IB_SIG_CHECK_GUARD;
234 }
235 
236 static inline void iser_inv_rkey(struct ib_send_wr *inv_wr, struct ib_mr *mr,
237 				 struct ib_cqe *cqe, struct ib_send_wr *next_wr)
238 {
239 	inv_wr->opcode = IB_WR_LOCAL_INV;
240 	inv_wr->wr_cqe = cqe;
241 	inv_wr->ex.invalidate_rkey = mr->rkey;
242 	inv_wr->send_flags = 0;
243 	inv_wr->num_sge = 0;
244 	inv_wr->next = next_wr;
245 }
246 
247 static int iser_reg_sig_mr(struct iscsi_iser_task *iser_task,
248 			   struct iser_data_buf *mem,
249 			   struct iser_data_buf *sig_mem,
250 			   struct iser_reg_resources *rsc,
251 			   struct iser_mem_reg *sig_reg)
252 {
253 	struct iser_tx_desc *tx_desc = &iser_task->desc;
254 	struct ib_cqe *cqe = &iser_task->iser_conn->ib_conn.reg_cqe;
255 	struct ib_mr *mr = rsc->sig_mr;
256 	struct ib_sig_attrs *sig_attrs = mr->sig_attrs;
257 	struct ib_reg_wr *wr = &tx_desc->reg_wr;
258 	int ret;
259 
260 	memset(sig_attrs, 0, sizeof(*sig_attrs));
261 	ret = iser_set_sig_attrs(iser_task->sc, sig_attrs);
262 	if (ret)
263 		goto err;
264 
265 	iser_set_prot_checks(iser_task->sc, &sig_attrs->check_mask);
266 
267 	if (rsc->sig_mr->need_inval)
268 		iser_inv_rkey(&tx_desc->inv_wr, mr, cqe, &wr->wr);
269 
270 	ib_update_fast_reg_key(mr, ib_inc_rkey(mr->rkey));
271 
272 	ret = ib_map_mr_sg_pi(mr, mem->sg, mem->dma_nents, NULL,
273 			      sig_mem->sg, sig_mem->dma_nents, NULL, SZ_4K);
274 	if (unlikely(ret)) {
275 		iser_err("failed to map PI sg (%d)\n",
276 			 mem->dma_nents + sig_mem->dma_nents);
277 		goto err;
278 	}
279 
280 	memset(wr, 0, sizeof(*wr));
281 	wr->wr.next = &tx_desc->send_wr;
282 	wr->wr.opcode = IB_WR_REG_MR_INTEGRITY;
283 	wr->wr.wr_cqe = cqe;
284 	wr->wr.num_sge = 0;
285 	wr->wr.send_flags = 0;
286 	wr->mr = mr;
287 	wr->key = mr->rkey;
288 	wr->access = IB_ACCESS_LOCAL_WRITE |
289 		     IB_ACCESS_REMOTE_READ |
290 		     IB_ACCESS_REMOTE_WRITE;
291 	rsc->sig_mr->need_inval = true;
292 
293 	sig_reg->sge.lkey = mr->lkey;
294 	sig_reg->rkey = mr->rkey;
295 	sig_reg->sge.addr = mr->iova;
296 	sig_reg->sge.length = mr->length;
297 
298 	iser_dbg("lkey=0x%x rkey=0x%x addr=0x%llx length=%u\n",
299 		 sig_reg->sge.lkey, sig_reg->rkey, sig_reg->sge.addr,
300 		 sig_reg->sge.length);
301 err:
302 	return ret;
303 }
304 
305 static int iser_fast_reg_mr(struct iscsi_iser_task *iser_task,
306 			    struct iser_data_buf *mem,
307 			    struct iser_reg_resources *rsc,
308 			    struct iser_mem_reg *reg)
309 {
310 	struct iser_tx_desc *tx_desc = &iser_task->desc;
311 	struct ib_cqe *cqe = &iser_task->iser_conn->ib_conn.reg_cqe;
312 	struct ib_mr *mr = rsc->mr;
313 	struct ib_reg_wr *wr = &tx_desc->reg_wr;
314 	int n;
315 
316 	if (rsc->mr->need_inval)
317 		iser_inv_rkey(&tx_desc->inv_wr, mr, cqe, &wr->wr);
318 
319 	ib_update_fast_reg_key(mr, ib_inc_rkey(mr->rkey));
320 
321 	n = ib_map_mr_sg(mr, mem->sg, mem->dma_nents, NULL, SZ_4K);
322 	if (unlikely(n != mem->dma_nents)) {
323 		iser_err("failed to map sg (%d/%d)\n",
324 			 n, mem->dma_nents);
325 		return n < 0 ? n : -EINVAL;
326 	}
327 
328 	wr->wr.next = &tx_desc->send_wr;
329 	wr->wr.opcode = IB_WR_REG_MR;
330 	wr->wr.wr_cqe = cqe;
331 	wr->wr.send_flags = 0;
332 	wr->wr.num_sge = 0;
333 	wr->mr = mr;
334 	wr->key = mr->rkey;
335 	wr->access = IB_ACCESS_LOCAL_WRITE  |
336 		     IB_ACCESS_REMOTE_WRITE |
337 		     IB_ACCESS_REMOTE_READ;
338 
339 	rsc->mr->need_inval = true;
340 
341 	reg->sge.lkey = mr->lkey;
342 	reg->rkey = mr->rkey;
343 	reg->sge.addr = mr->iova;
344 	reg->sge.length = mr->length;
345 
346 	iser_dbg("lkey=0x%x rkey=0x%x addr=0x%llx length=0x%x\n",
347 		 reg->sge.lkey, reg->rkey, reg->sge.addr, reg->sge.length);
348 
349 	return 0;
350 }
351 
352 int iser_reg_mem_fastreg(struct iscsi_iser_task *task,
353 			 enum iser_data_dir dir,
354 			 bool all_imm)
355 {
356 	struct ib_conn *ib_conn = &task->iser_conn->ib_conn;
357 	struct iser_device *device = ib_conn->device;
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;
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 	if (use_dma_key)
367 		return iser_reg_dma(device, mem, reg);
368 
369 	desc = iser_reg_desc_get_fr(ib_conn);
370 	if (scsi_get_prot_op(task->sc) == SCSI_PROT_NORMAL) {
371 		err = iser_fast_reg_mr(task, mem, &desc->rsc, reg);
372 		if (unlikely(err))
373 			goto err_reg;
374 	} else {
375 		err = iser_reg_sig_mr(task, mem, &task->prot[dir],
376 				      &desc->rsc, reg);
377 		if (unlikely(err))
378 			goto err_reg;
379 
380 		desc->sig_protected = true;
381 	}
382 
383 	reg->desc = desc;
384 
385 	return 0;
386 
387 err_reg:
388 	iser_reg_desc_put_fr(ib_conn, desc);
389 
390 	return err;
391 }
392