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
41void iser_reg_comp(struct ib_cq *cq, struct ib_wc *wc)
42{
43	iser_err_comp(wc, "memreg");
44}
45
46static 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
61static 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
72int 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
100out_unmap:
101	ib_dma_unmap_sg(dev, data->sg, data->size, dma_dir);
102	return -EINVAL;
103}
104
105
106void 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
123static 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
148void 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
176static 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
193static 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
227static 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
236static 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
247static 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);
301err:
302	return ret;
303}
304
305static 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
352int 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
387err_reg:
388	iser_reg_desc_put_fr(ib_conn, desc);
389
390	return err;
391}
392