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
42void iser_reg_comp(struct ib_cq *cq, struct ib_wc *wc)
43{
44	iser_err_comp(wc, "memreg");
45}
46
47static struct iser_fr_desc *
48iser_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
63static void
64iser_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
75int 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
93void 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
103static int
104iser_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
129void 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
157static void
158iser_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(sc->request);
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
174static int
175iser_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
208static inline void
209iser_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
218static inline void
219iser_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
232static int
233iser_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->sig_mr->need_inval)
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->sig_mr->need_inval = true;
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);
287err:
288	return ret;
289}
290
291static 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->need_inval)
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->need_inval = true;
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
338static int
339iser_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
353int 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
387err_reg:
388	if (desc)
389		iser_reg_desc_put_fr(ib_conn, desc);
390
391	return err;
392}
393
394