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v3.1
  1/*
  2 * SCSI RDMA Protocol lib functions
  3 *
  4 * Copyright (C) 2006 FUJITA Tomonori <tomof@acm.org>
  5 *
  6 * This program is free software; you can redistribute it and/or
  7 * modify it under the terms of the GNU General Public License as
  8 * published by the Free Software Foundation; either version 2 of the
  9 * License, or (at your option) any later version.
 10 *
 11 * This program is distributed in the hope that it will be useful, but
 12 * WITHOUT ANY WARRANTY; without even the implied warranty of
 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 14 * General Public License for more details.
 15 *
 16 * You should have received a copy of the GNU General Public License
 17 * along with this program; if not, write to the Free Software
 18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 19 * 02110-1301 USA
 20 */
 21#include <linux/err.h>
 22#include <linux/slab.h>
 23#include <linux/kfifo.h>
 24#include <linux/scatterlist.h>
 25#include <linux/dma-mapping.h>
 
 26#include <scsi/scsi.h>
 27#include <scsi/scsi_cmnd.h>
 28#include <scsi/scsi_tcq.h>
 29#include <scsi/scsi_tgt.h>
 30#include <scsi/srp.h>
 31#include <scsi/libsrp.h>
 32
 33enum srp_task_attributes {
 34	SRP_SIMPLE_TASK = 0,
 35	SRP_HEAD_TASK = 1,
 36	SRP_ORDERED_TASK = 2,
 37	SRP_ACA_TASK = 4
 38};
 39
 40/* tmp - will replace with SCSI logging stuff */
 41#define eprintk(fmt, args...)					\
 42do {								\
 43	printk("%s(%d) " fmt, __func__, __LINE__, ##args);	\
 44} while (0)
 45/* #define dprintk eprintk */
 46#define dprintk(fmt, args...)
 47
 48static int srp_iu_pool_alloc(struct srp_queue *q, size_t max,
 49			     struct srp_buf **ring)
 50{
 51	int i;
 52	struct iu_entry *iue;
 53
 54	q->pool = kcalloc(max, sizeof(struct iu_entry *), GFP_KERNEL);
 55	if (!q->pool)
 56		return -ENOMEM;
 57	q->items = kcalloc(max, sizeof(struct iu_entry), GFP_KERNEL);
 58	if (!q->items)
 59		goto free_pool;
 60
 61	spin_lock_init(&q->lock);
 62	kfifo_init(&q->queue, (void *) q->pool, max * sizeof(void *));
 63
 64	for (i = 0, iue = q->items; i < max; i++) {
 65		kfifo_in(&q->queue, (void *) &iue, sizeof(void *));
 66		iue->sbuf = ring[i];
 67		iue++;
 68	}
 69	return 0;
 70
 71	kfree(q->items);
 72free_pool:
 73	kfree(q->pool);
 74	return -ENOMEM;
 75}
 76
 77static void srp_iu_pool_free(struct srp_queue *q)
 78{
 79	kfree(q->items);
 80	kfree(q->pool);
 81}
 82
 83static struct srp_buf **srp_ring_alloc(struct device *dev,
 84				       size_t max, size_t size)
 85{
 86	int i;
 87	struct srp_buf **ring;
 88
 89	ring = kcalloc(max, sizeof(struct srp_buf *), GFP_KERNEL);
 90	if (!ring)
 91		return NULL;
 92
 93	for (i = 0; i < max; i++) {
 94		ring[i] = kzalloc(sizeof(struct srp_buf), GFP_KERNEL);
 95		if (!ring[i])
 96			goto out;
 97		ring[i]->buf = dma_alloc_coherent(dev, size, &ring[i]->dma,
 98						  GFP_KERNEL);
 99		if (!ring[i]->buf)
100			goto out;
101	}
102	return ring;
103
104out:
105	for (i = 0; i < max && ring[i]; i++) {
106		if (ring[i]->buf)
107			dma_free_coherent(dev, size, ring[i]->buf, ring[i]->dma);
108		kfree(ring[i]);
109	}
110	kfree(ring);
111
112	return NULL;
113}
114
115static void srp_ring_free(struct device *dev, struct srp_buf **ring, size_t max,
116			  size_t size)
117{
118	int i;
119
120	for (i = 0; i < max; i++) {
121		dma_free_coherent(dev, size, ring[i]->buf, ring[i]->dma);
122		kfree(ring[i]);
123	}
124	kfree(ring);
125}
126
127int srp_target_alloc(struct srp_target *target, struct device *dev,
128		     size_t nr, size_t iu_size)
129{
130	int err;
131
132	spin_lock_init(&target->lock);
133	INIT_LIST_HEAD(&target->cmd_queue);
134
135	target->dev = dev;
136	dev_set_drvdata(target->dev, target);
137
138	target->srp_iu_size = iu_size;
139	target->rx_ring_size = nr;
140	target->rx_ring = srp_ring_alloc(target->dev, nr, iu_size);
141	if (!target->rx_ring)
142		return -ENOMEM;
143	err = srp_iu_pool_alloc(&target->iu_queue, nr, target->rx_ring);
144	if (err)
145		goto free_ring;
146
147	return 0;
148
149free_ring:
150	srp_ring_free(target->dev, target->rx_ring, nr, iu_size);
151	return -ENOMEM;
152}
153EXPORT_SYMBOL_GPL(srp_target_alloc);
154
155void srp_target_free(struct srp_target *target)
156{
157	srp_ring_free(target->dev, target->rx_ring, target->rx_ring_size,
158		      target->srp_iu_size);
159	srp_iu_pool_free(&target->iu_queue);
160}
161EXPORT_SYMBOL_GPL(srp_target_free);
162
163struct iu_entry *srp_iu_get(struct srp_target *target)
164{
165	struct iu_entry *iue = NULL;
166
167	if (kfifo_out_locked(&target->iu_queue.queue, (void *) &iue,
168		sizeof(void *), &target->iu_queue.lock) != sizeof(void *)) {
169			WARN_ONCE(1, "unexpected fifo state");
170			return NULL;
171	}
172	if (!iue)
173		return iue;
174	iue->target = target;
175	INIT_LIST_HEAD(&iue->ilist);
176	iue->flags = 0;
177	return iue;
178}
179EXPORT_SYMBOL_GPL(srp_iu_get);
180
181void srp_iu_put(struct iu_entry *iue)
182{
183	kfifo_in_locked(&iue->target->iu_queue.queue, (void *) &iue,
184			sizeof(void *), &iue->target->iu_queue.lock);
185}
186EXPORT_SYMBOL_GPL(srp_iu_put);
187
188static int srp_direct_data(struct scsi_cmnd *sc, struct srp_direct_buf *md,
189			   enum dma_data_direction dir, srp_rdma_t rdma_io,
190			   int dma_map, int ext_desc)
191{
192	struct iu_entry *iue = NULL;
193	struct scatterlist *sg = NULL;
194	int err, nsg = 0, len;
195
196	if (dma_map) {
197		iue = (struct iu_entry *) sc->SCp.ptr;
198		sg = scsi_sglist(sc);
199
200		dprintk("%p %u %u %d\n", iue, scsi_bufflen(sc),
201			md->len, scsi_sg_count(sc));
202
203		nsg = dma_map_sg(iue->target->dev, sg, scsi_sg_count(sc),
204				 DMA_BIDIRECTIONAL);
205		if (!nsg) {
206			printk("fail to map %p %d\n", iue, scsi_sg_count(sc));
207			return 0;
208		}
209		len = min(scsi_bufflen(sc), md->len);
210	} else
211		len = md->len;
212
213	err = rdma_io(sc, sg, nsg, md, 1, dir, len);
214
215	if (dma_map)
216		dma_unmap_sg(iue->target->dev, sg, nsg, DMA_BIDIRECTIONAL);
217
218	return err;
219}
220
221static int srp_indirect_data(struct scsi_cmnd *sc, struct srp_cmd *cmd,
222			     struct srp_indirect_buf *id,
223			     enum dma_data_direction dir, srp_rdma_t rdma_io,
224			     int dma_map, int ext_desc)
225{
226	struct iu_entry *iue = NULL;
227	struct srp_direct_buf *md = NULL;
228	struct scatterlist dummy, *sg = NULL;
229	dma_addr_t token = 0;
230	int err = 0;
231	int nmd, nsg = 0, len;
232
233	if (dma_map || ext_desc) {
234		iue = (struct iu_entry *) sc->SCp.ptr;
235		sg = scsi_sglist(sc);
236
237		dprintk("%p %u %u %d %d\n",
238			iue, scsi_bufflen(sc), id->len,
239			cmd->data_in_desc_cnt, cmd->data_out_desc_cnt);
240	}
241
242	nmd = id->table_desc.len / sizeof(struct srp_direct_buf);
243
244	if ((dir == DMA_FROM_DEVICE && nmd == cmd->data_in_desc_cnt) ||
245	    (dir == DMA_TO_DEVICE && nmd == cmd->data_out_desc_cnt)) {
246		md = &id->desc_list[0];
247		goto rdma;
248	}
249
250	if (ext_desc && dma_map) {
251		md = dma_alloc_coherent(iue->target->dev, id->table_desc.len,
252				&token, GFP_KERNEL);
253		if (!md) {
254			eprintk("Can't get dma memory %u\n", id->table_desc.len);
255			return -ENOMEM;
256		}
257
258		sg_init_one(&dummy, md, id->table_desc.len);
259		sg_dma_address(&dummy) = token;
260		sg_dma_len(&dummy) = id->table_desc.len;
261		err = rdma_io(sc, &dummy, 1, &id->table_desc, 1, DMA_TO_DEVICE,
262			      id->table_desc.len);
263		if (err) {
264			eprintk("Error copying indirect table %d\n", err);
265			goto free_mem;
266		}
267	} else {
268		eprintk("This command uses external indirect buffer\n");
269		return -EINVAL;
270	}
271
272rdma:
273	if (dma_map) {
274		nsg = dma_map_sg(iue->target->dev, sg, scsi_sg_count(sc),
275				 DMA_BIDIRECTIONAL);
276		if (!nsg) {
277			eprintk("fail to map %p %d\n", iue, scsi_sg_count(sc));
278			err = -EIO;
279			goto free_mem;
280		}
281		len = min(scsi_bufflen(sc), id->len);
282	} else
283		len = id->len;
284
285	err = rdma_io(sc, sg, nsg, md, nmd, dir, len);
286
287	if (dma_map)
288		dma_unmap_sg(iue->target->dev, sg, nsg, DMA_BIDIRECTIONAL);
289
290free_mem:
291	if (token && dma_map)
292		dma_free_coherent(iue->target->dev, id->table_desc.len, md, token);
293
294	return err;
295}
296
297static int data_out_desc_size(struct srp_cmd *cmd)
298{
299	int size = 0;
300	u8 fmt = cmd->buf_fmt >> 4;
301
302	switch (fmt) {
303	case SRP_NO_DATA_DESC:
304		break;
305	case SRP_DATA_DESC_DIRECT:
306		size = sizeof(struct srp_direct_buf);
307		break;
308	case SRP_DATA_DESC_INDIRECT:
309		size = sizeof(struct srp_indirect_buf) +
310			sizeof(struct srp_direct_buf) * cmd->data_out_desc_cnt;
311		break;
312	default:
313		eprintk("client error. Invalid data_out_format %x\n", fmt);
314		break;
315	}
316	return size;
317}
318
319/*
320 * TODO: this can be called multiple times for a single command if it
321 * has very long data.
322 */
323int srp_transfer_data(struct scsi_cmnd *sc, struct srp_cmd *cmd,
324		      srp_rdma_t rdma_io, int dma_map, int ext_desc)
325{
326	struct srp_direct_buf *md;
327	struct srp_indirect_buf *id;
328	enum dma_data_direction dir;
329	int offset, err = 0;
330	u8 format;
331
332	offset = cmd->add_cdb_len & ~3;
333
334	dir = srp_cmd_direction(cmd);
335	if (dir == DMA_FROM_DEVICE)
336		offset += data_out_desc_size(cmd);
337
338	if (dir == DMA_TO_DEVICE)
339		format = cmd->buf_fmt >> 4;
340	else
341		format = cmd->buf_fmt & ((1U << 4) - 1);
342
343	switch (format) {
344	case SRP_NO_DATA_DESC:
345		break;
346	case SRP_DATA_DESC_DIRECT:
347		md = (struct srp_direct_buf *)
348			(cmd->add_data + offset);
349		err = srp_direct_data(sc, md, dir, rdma_io, dma_map, ext_desc);
350		break;
351	case SRP_DATA_DESC_INDIRECT:
352		id = (struct srp_indirect_buf *)
353			(cmd->add_data + offset);
354		err = srp_indirect_data(sc, cmd, id, dir, rdma_io, dma_map,
355					ext_desc);
356		break;
357	default:
358		eprintk("Unknown format %d %x\n", dir, format);
359		err = -EINVAL;
360	}
361
362	return err;
363}
364EXPORT_SYMBOL_GPL(srp_transfer_data);
365
366static int vscsis_data_length(struct srp_cmd *cmd, enum dma_data_direction dir)
367{
368	struct srp_direct_buf *md;
369	struct srp_indirect_buf *id;
370	int len = 0, offset = cmd->add_cdb_len & ~3;
371	u8 fmt;
372
373	if (dir == DMA_TO_DEVICE)
374		fmt = cmd->buf_fmt >> 4;
375	else {
376		fmt = cmd->buf_fmt & ((1U << 4) - 1);
377		offset += data_out_desc_size(cmd);
378	}
379
380	switch (fmt) {
381	case SRP_NO_DATA_DESC:
382		break;
383	case SRP_DATA_DESC_DIRECT:
384		md = (struct srp_direct_buf *) (cmd->add_data + offset);
385		len = md->len;
386		break;
387	case SRP_DATA_DESC_INDIRECT:
388		id = (struct srp_indirect_buf *) (cmd->add_data + offset);
389		len = id->len;
390		break;
391	default:
392		eprintk("invalid data format %x\n", fmt);
393		break;
394	}
395	return len;
396}
397
398int srp_cmd_queue(struct Scsi_Host *shost, struct srp_cmd *cmd, void *info,
399		  u64 itn_id, u64 addr)
400{
401	enum dma_data_direction dir;
402	struct scsi_cmnd *sc;
403	int tag, len, err;
404
405	switch (cmd->task_attr) {
406	case SRP_SIMPLE_TASK:
407		tag = MSG_SIMPLE_TAG;
408		break;
409	case SRP_ORDERED_TASK:
410		tag = MSG_ORDERED_TAG;
411		break;
412	case SRP_HEAD_TASK:
413		tag = MSG_HEAD_TAG;
414		break;
415	default:
416		eprintk("Task attribute %d not supported\n", cmd->task_attr);
417		tag = MSG_ORDERED_TAG;
418	}
419
420	dir = srp_cmd_direction(cmd);
421	len = vscsis_data_length(cmd, dir);
422
423	dprintk("%p %x %lx %d %d %d %llx\n", info, cmd->cdb[0],
424		cmd->lun, dir, len, tag, (unsigned long long) cmd->tag);
425
426	sc = scsi_host_get_command(shost, dir, GFP_KERNEL);
427	if (!sc)
428		return -ENOMEM;
429
430	sc->SCp.ptr = info;
431	memcpy(sc->cmnd, cmd->cdb, MAX_COMMAND_SIZE);
432	sc->sdb.length = len;
433	sc->sdb.table.sgl = (void *) (unsigned long) addr;
434	sc->tag = tag;
435	err = scsi_tgt_queue_command(sc, itn_id, (struct scsi_lun *)&cmd->lun,
436				     cmd->tag);
437	if (err)
438		scsi_host_put_command(shost, sc);
439
440	return err;
441}
442EXPORT_SYMBOL_GPL(srp_cmd_queue);
443
444MODULE_DESCRIPTION("SCSI RDMA Protocol lib functions");
445MODULE_AUTHOR("FUJITA Tomonori");
446MODULE_LICENSE("GPL");
v3.5.6
  1/*
  2 * SCSI RDMA Protocol lib functions
  3 *
  4 * Copyright (C) 2006 FUJITA Tomonori <tomof@acm.org>
  5 *
  6 * This program is free software; you can redistribute it and/or
  7 * modify it under the terms of the GNU General Public License as
  8 * published by the Free Software Foundation; either version 2 of the
  9 * License, or (at your option) any later version.
 10 *
 11 * This program is distributed in the hope that it will be useful, but
 12 * WITHOUT ANY WARRANTY; without even the implied warranty of
 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 14 * General Public License for more details.
 15 *
 16 * You should have received a copy of the GNU General Public License
 17 * along with this program; if not, write to the Free Software
 18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 19 * 02110-1301 USA
 20 */
 21#include <linux/err.h>
 22#include <linux/slab.h>
 23#include <linux/kfifo.h>
 24#include <linux/scatterlist.h>
 25#include <linux/dma-mapping.h>
 26#include <linux/module.h>
 27#include <scsi/scsi.h>
 28#include <scsi/scsi_cmnd.h>
 29#include <scsi/scsi_tcq.h>
 30#include <scsi/scsi_tgt.h>
 31#include <scsi/srp.h>
 32#include <scsi/libsrp.h>
 33
 34enum srp_task_attributes {
 35	SRP_SIMPLE_TASK = 0,
 36	SRP_HEAD_TASK = 1,
 37	SRP_ORDERED_TASK = 2,
 38	SRP_ACA_TASK = 4
 39};
 40
 41/* tmp - will replace with SCSI logging stuff */
 42#define eprintk(fmt, args...)					\
 43do {								\
 44	printk("%s(%d) " fmt, __func__, __LINE__, ##args);	\
 45} while (0)
 46/* #define dprintk eprintk */
 47#define dprintk(fmt, args...)
 48
 49static int srp_iu_pool_alloc(struct srp_queue *q, size_t max,
 50			     struct srp_buf **ring)
 51{
 52	int i;
 53	struct iu_entry *iue;
 54
 55	q->pool = kcalloc(max, sizeof(struct iu_entry *), GFP_KERNEL);
 56	if (!q->pool)
 57		return -ENOMEM;
 58	q->items = kcalloc(max, sizeof(struct iu_entry), GFP_KERNEL);
 59	if (!q->items)
 60		goto free_pool;
 61
 62	spin_lock_init(&q->lock);
 63	kfifo_init(&q->queue, (void *) q->pool, max * sizeof(void *));
 64
 65	for (i = 0, iue = q->items; i < max; i++) {
 66		kfifo_in(&q->queue, (void *) &iue, sizeof(void *));
 67		iue->sbuf = ring[i];
 68		iue++;
 69	}
 70	return 0;
 71
 72	kfree(q->items);
 73free_pool:
 74	kfree(q->pool);
 75	return -ENOMEM;
 76}
 77
 78static void srp_iu_pool_free(struct srp_queue *q)
 79{
 80	kfree(q->items);
 81	kfree(q->pool);
 82}
 83
 84static struct srp_buf **srp_ring_alloc(struct device *dev,
 85				       size_t max, size_t size)
 86{
 87	int i;
 88	struct srp_buf **ring;
 89
 90	ring = kcalloc(max, sizeof(struct srp_buf *), GFP_KERNEL);
 91	if (!ring)
 92		return NULL;
 93
 94	for (i = 0; i < max; i++) {
 95		ring[i] = kzalloc(sizeof(struct srp_buf), GFP_KERNEL);
 96		if (!ring[i])
 97			goto out;
 98		ring[i]->buf = dma_alloc_coherent(dev, size, &ring[i]->dma,
 99						  GFP_KERNEL);
100		if (!ring[i]->buf)
101			goto out;
102	}
103	return ring;
104
105out:
106	for (i = 0; i < max && ring[i]; i++) {
107		if (ring[i]->buf)
108			dma_free_coherent(dev, size, ring[i]->buf, ring[i]->dma);
109		kfree(ring[i]);
110	}
111	kfree(ring);
112
113	return NULL;
114}
115
116static void srp_ring_free(struct device *dev, struct srp_buf **ring, size_t max,
117			  size_t size)
118{
119	int i;
120
121	for (i = 0; i < max; i++) {
122		dma_free_coherent(dev, size, ring[i]->buf, ring[i]->dma);
123		kfree(ring[i]);
124	}
125	kfree(ring);
126}
127
128int srp_target_alloc(struct srp_target *target, struct device *dev,
129		     size_t nr, size_t iu_size)
130{
131	int err;
132
133	spin_lock_init(&target->lock);
134	INIT_LIST_HEAD(&target->cmd_queue);
135
136	target->dev = dev;
137	dev_set_drvdata(target->dev, target);
138
139	target->srp_iu_size = iu_size;
140	target->rx_ring_size = nr;
141	target->rx_ring = srp_ring_alloc(target->dev, nr, iu_size);
142	if (!target->rx_ring)
143		return -ENOMEM;
144	err = srp_iu_pool_alloc(&target->iu_queue, nr, target->rx_ring);
145	if (err)
146		goto free_ring;
147
148	return 0;
149
150free_ring:
151	srp_ring_free(target->dev, target->rx_ring, nr, iu_size);
152	return -ENOMEM;
153}
154EXPORT_SYMBOL_GPL(srp_target_alloc);
155
156void srp_target_free(struct srp_target *target)
157{
158	srp_ring_free(target->dev, target->rx_ring, target->rx_ring_size,
159		      target->srp_iu_size);
160	srp_iu_pool_free(&target->iu_queue);
161}
162EXPORT_SYMBOL_GPL(srp_target_free);
163
164struct iu_entry *srp_iu_get(struct srp_target *target)
165{
166	struct iu_entry *iue = NULL;
167
168	if (kfifo_out_locked(&target->iu_queue.queue, (void *) &iue,
169		sizeof(void *), &target->iu_queue.lock) != sizeof(void *)) {
170			WARN_ONCE(1, "unexpected fifo state");
171			return NULL;
172	}
173	if (!iue)
174		return iue;
175	iue->target = target;
176	INIT_LIST_HEAD(&iue->ilist);
177	iue->flags = 0;
178	return iue;
179}
180EXPORT_SYMBOL_GPL(srp_iu_get);
181
182void srp_iu_put(struct iu_entry *iue)
183{
184	kfifo_in_locked(&iue->target->iu_queue.queue, (void *) &iue,
185			sizeof(void *), &iue->target->iu_queue.lock);
186}
187EXPORT_SYMBOL_GPL(srp_iu_put);
188
189static int srp_direct_data(struct scsi_cmnd *sc, struct srp_direct_buf *md,
190			   enum dma_data_direction dir, srp_rdma_t rdma_io,
191			   int dma_map, int ext_desc)
192{
193	struct iu_entry *iue = NULL;
194	struct scatterlist *sg = NULL;
195	int err, nsg = 0, len;
196
197	if (dma_map) {
198		iue = (struct iu_entry *) sc->SCp.ptr;
199		sg = scsi_sglist(sc);
200
201		dprintk("%p %u %u %d\n", iue, scsi_bufflen(sc),
202			md->len, scsi_sg_count(sc));
203
204		nsg = dma_map_sg(iue->target->dev, sg, scsi_sg_count(sc),
205				 DMA_BIDIRECTIONAL);
206		if (!nsg) {
207			printk("fail to map %p %d\n", iue, scsi_sg_count(sc));
208			return 0;
209		}
210		len = min(scsi_bufflen(sc), md->len);
211	} else
212		len = md->len;
213
214	err = rdma_io(sc, sg, nsg, md, 1, dir, len);
215
216	if (dma_map)
217		dma_unmap_sg(iue->target->dev, sg, nsg, DMA_BIDIRECTIONAL);
218
219	return err;
220}
221
222static int srp_indirect_data(struct scsi_cmnd *sc, struct srp_cmd *cmd,
223			     struct srp_indirect_buf *id,
224			     enum dma_data_direction dir, srp_rdma_t rdma_io,
225			     int dma_map, int ext_desc)
226{
227	struct iu_entry *iue = NULL;
228	struct srp_direct_buf *md = NULL;
229	struct scatterlist dummy, *sg = NULL;
230	dma_addr_t token = 0;
231	int err = 0;
232	int nmd, nsg = 0, len;
233
234	if (dma_map || ext_desc) {
235		iue = (struct iu_entry *) sc->SCp.ptr;
236		sg = scsi_sglist(sc);
237
238		dprintk("%p %u %u %d %d\n",
239			iue, scsi_bufflen(sc), id->len,
240			cmd->data_in_desc_cnt, cmd->data_out_desc_cnt);
241	}
242
243	nmd = id->table_desc.len / sizeof(struct srp_direct_buf);
244
245	if ((dir == DMA_FROM_DEVICE && nmd == cmd->data_in_desc_cnt) ||
246	    (dir == DMA_TO_DEVICE && nmd == cmd->data_out_desc_cnt)) {
247		md = &id->desc_list[0];
248		goto rdma;
249	}
250
251	if (ext_desc && dma_map) {
252		md = dma_alloc_coherent(iue->target->dev, id->table_desc.len,
253				&token, GFP_KERNEL);
254		if (!md) {
255			eprintk("Can't get dma memory %u\n", id->table_desc.len);
256			return -ENOMEM;
257		}
258
259		sg_init_one(&dummy, md, id->table_desc.len);
260		sg_dma_address(&dummy) = token;
261		sg_dma_len(&dummy) = id->table_desc.len;
262		err = rdma_io(sc, &dummy, 1, &id->table_desc, 1, DMA_TO_DEVICE,
263			      id->table_desc.len);
264		if (err) {
265			eprintk("Error copying indirect table %d\n", err);
266			goto free_mem;
267		}
268	} else {
269		eprintk("This command uses external indirect buffer\n");
270		return -EINVAL;
271	}
272
273rdma:
274	if (dma_map) {
275		nsg = dma_map_sg(iue->target->dev, sg, scsi_sg_count(sc),
276				 DMA_BIDIRECTIONAL);
277		if (!nsg) {
278			eprintk("fail to map %p %d\n", iue, scsi_sg_count(sc));
279			err = -EIO;
280			goto free_mem;
281		}
282		len = min(scsi_bufflen(sc), id->len);
283	} else
284		len = id->len;
285
286	err = rdma_io(sc, sg, nsg, md, nmd, dir, len);
287
288	if (dma_map)
289		dma_unmap_sg(iue->target->dev, sg, nsg, DMA_BIDIRECTIONAL);
290
291free_mem:
292	if (token && dma_map)
293		dma_free_coherent(iue->target->dev, id->table_desc.len, md, token);
294
295	return err;
296}
297
298static int data_out_desc_size(struct srp_cmd *cmd)
299{
300	int size = 0;
301	u8 fmt = cmd->buf_fmt >> 4;
302
303	switch (fmt) {
304	case SRP_NO_DATA_DESC:
305		break;
306	case SRP_DATA_DESC_DIRECT:
307		size = sizeof(struct srp_direct_buf);
308		break;
309	case SRP_DATA_DESC_INDIRECT:
310		size = sizeof(struct srp_indirect_buf) +
311			sizeof(struct srp_direct_buf) * cmd->data_out_desc_cnt;
312		break;
313	default:
314		eprintk("client error. Invalid data_out_format %x\n", fmt);
315		break;
316	}
317	return size;
318}
319
320/*
321 * TODO: this can be called multiple times for a single command if it
322 * has very long data.
323 */
324int srp_transfer_data(struct scsi_cmnd *sc, struct srp_cmd *cmd,
325		      srp_rdma_t rdma_io, int dma_map, int ext_desc)
326{
327	struct srp_direct_buf *md;
328	struct srp_indirect_buf *id;
329	enum dma_data_direction dir;
330	int offset, err = 0;
331	u8 format;
332
333	offset = cmd->add_cdb_len & ~3;
334
335	dir = srp_cmd_direction(cmd);
336	if (dir == DMA_FROM_DEVICE)
337		offset += data_out_desc_size(cmd);
338
339	if (dir == DMA_TO_DEVICE)
340		format = cmd->buf_fmt >> 4;
341	else
342		format = cmd->buf_fmt & ((1U << 4) - 1);
343
344	switch (format) {
345	case SRP_NO_DATA_DESC:
346		break;
347	case SRP_DATA_DESC_DIRECT:
348		md = (struct srp_direct_buf *)
349			(cmd->add_data + offset);
350		err = srp_direct_data(sc, md, dir, rdma_io, dma_map, ext_desc);
351		break;
352	case SRP_DATA_DESC_INDIRECT:
353		id = (struct srp_indirect_buf *)
354			(cmd->add_data + offset);
355		err = srp_indirect_data(sc, cmd, id, dir, rdma_io, dma_map,
356					ext_desc);
357		break;
358	default:
359		eprintk("Unknown format %d %x\n", dir, format);
360		err = -EINVAL;
361	}
362
363	return err;
364}
365EXPORT_SYMBOL_GPL(srp_transfer_data);
366
367static int vscsis_data_length(struct srp_cmd *cmd, enum dma_data_direction dir)
368{
369	struct srp_direct_buf *md;
370	struct srp_indirect_buf *id;
371	int len = 0, offset = cmd->add_cdb_len & ~3;
372	u8 fmt;
373
374	if (dir == DMA_TO_DEVICE)
375		fmt = cmd->buf_fmt >> 4;
376	else {
377		fmt = cmd->buf_fmt & ((1U << 4) - 1);
378		offset += data_out_desc_size(cmd);
379	}
380
381	switch (fmt) {
382	case SRP_NO_DATA_DESC:
383		break;
384	case SRP_DATA_DESC_DIRECT:
385		md = (struct srp_direct_buf *) (cmd->add_data + offset);
386		len = md->len;
387		break;
388	case SRP_DATA_DESC_INDIRECT:
389		id = (struct srp_indirect_buf *) (cmd->add_data + offset);
390		len = id->len;
391		break;
392	default:
393		eprintk("invalid data format %x\n", fmt);
394		break;
395	}
396	return len;
397}
398
399int srp_cmd_queue(struct Scsi_Host *shost, struct srp_cmd *cmd, void *info,
400		  u64 itn_id, u64 addr)
401{
402	enum dma_data_direction dir;
403	struct scsi_cmnd *sc;
404	int tag, len, err;
405
406	switch (cmd->task_attr) {
407	case SRP_SIMPLE_TASK:
408		tag = MSG_SIMPLE_TAG;
409		break;
410	case SRP_ORDERED_TASK:
411		tag = MSG_ORDERED_TAG;
412		break;
413	case SRP_HEAD_TASK:
414		tag = MSG_HEAD_TAG;
415		break;
416	default:
417		eprintk("Task attribute %d not supported\n", cmd->task_attr);
418		tag = MSG_ORDERED_TAG;
419	}
420
421	dir = srp_cmd_direction(cmd);
422	len = vscsis_data_length(cmd, dir);
423
424	dprintk("%p %x %lx %d %d %d %llx\n", info, cmd->cdb[0],
425		cmd->lun, dir, len, tag, (unsigned long long) cmd->tag);
426
427	sc = scsi_host_get_command(shost, dir, GFP_KERNEL);
428	if (!sc)
429		return -ENOMEM;
430
431	sc->SCp.ptr = info;
432	memcpy(sc->cmnd, cmd->cdb, MAX_COMMAND_SIZE);
433	sc->sdb.length = len;
434	sc->sdb.table.sgl = (void *) (unsigned long) addr;
435	sc->tag = tag;
436	err = scsi_tgt_queue_command(sc, itn_id, (struct scsi_lun *)&cmd->lun,
437				     cmd->tag);
438	if (err)
439		scsi_host_put_command(shost, sc);
440
441	return err;
442}
443EXPORT_SYMBOL_GPL(srp_cmd_queue);
444
445MODULE_DESCRIPTION("SCSI RDMA Protocol lib functions");
446MODULE_AUTHOR("FUJITA Tomonori");
447MODULE_LICENSE("GPL");