summaryrefslogtreecommitdiffstats
path: root/drivers/scsi/cxgb3i/cxgb3i_pdu.c
blob: 17115c230d6582ca8d8522166f774a999727ed3f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
/*
 * cxgb3i_pdu.c: Chelsio S3xx iSCSI driver.
 *
 * Copyright (c) 2008 Chelsio Communications, Inc.
 * Copyright (c) 2008 Mike Christie
 * Copyright (c) 2008 Red Hat, Inc.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation.
 *
 * Written by: Karen Xie (kxie@chelsio.com)
 */

#include <linux/skbuff.h>
#include <linux/crypto.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_host.h>

#include "cxgb3i.h"
#include "cxgb3i_pdu.h"

#ifdef __DEBUG_CXGB3I_RX__
#define cxgb3i_rx_debug		cxgb3i_log_debug
#else
#define cxgb3i_rx_debug(fmt...)
#endif

#ifdef __DEBUG_CXGB3I_TX__
#define cxgb3i_tx_debug		cxgb3i_log_debug
#else
#define cxgb3i_tx_debug(fmt...)
#endif

/* always allocate rooms for AHS */
#define SKB_TX_PDU_HEADER_LEN	\
	(sizeof(struct iscsi_hdr) + ISCSI_MAX_AHS_SIZE)
static unsigned int skb_extra_headroom;
static struct page *pad_page;

/*
 * pdu receive, interact with libiscsi_tcp
 */
static inline int read_pdu_skb(struct iscsi_conn *conn, struct sk_buff *skb,
			       unsigned int offset, int offloaded)
{
	int status = 0;
	int bytes_read;

	bytes_read = iscsi_tcp_recv_skb(conn, skb, offset, offloaded, &status);
	switch (status) {
	case ISCSI_TCP_CONN_ERR:
		return -EIO;
	case ISCSI_TCP_SUSPENDED:
		/* no transfer - just have caller flush queue */
		return bytes_read;
	case ISCSI_TCP_SKB_DONE:
		/*
		 * pdus should always fit in the skb and we should get
		 * segment done notifcation.
		 */
		iscsi_conn_printk(KERN_ERR, conn, "Invalid pdu or skb.");
		return -EFAULT;
	case ISCSI_TCP_SEGMENT_DONE:
		return bytes_read;
	default:
		iscsi_conn_printk(KERN_ERR, conn, "Invalid iscsi_tcp_recv_skb "
				  "status %d\n", status);
		return -EINVAL;
	}
}

static int cxgb3i_conn_read_pdu_skb(struct iscsi_conn *conn,
				    struct sk_buff *skb)
{
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
	bool offloaded = 0;
	unsigned int offset;
	int rc;

	cxgb3i_rx_debug("conn 0x%p, skb 0x%p, len %u, flag 0x%x.\n",
			conn, skb, skb->len, skb_ulp_mode(skb));

	if (!iscsi_tcp_recv_segment_is_hdr(tcp_conn)) {
		iscsi_conn_failure(conn, ISCSI_ERR_PROTO);
		return -EIO;
	}

	if (conn->hdrdgst_en && (skb_ulp_mode(skb) & ULP2_FLAG_HCRC_ERROR)) {
		iscsi_conn_failure(conn, ISCSI_ERR_HDR_DGST);
		return -EIO;
	}

	if (conn->datadgst_en && (skb_ulp_mode(skb) & ULP2_FLAG_DCRC_ERROR)) {
		iscsi_conn_failure(conn, ISCSI_ERR_DATA_DGST);
		return -EIO;
	}

	/* iscsi hdr */
	rc = read_pdu_skb(conn, skb, 0, 0);
	if (rc <= 0)
		return rc;

	if (iscsi_tcp_recv_segment_is_hdr(tcp_conn))
		return 0;

	offset = rc;
	if (conn->hdrdgst_en)
		offset += ISCSI_DIGEST_SIZE;

	/* iscsi data */
	if (skb_ulp_mode(skb) & ULP2_FLAG_DATA_DDPED) {
		cxgb3i_rx_debug("skb 0x%p, opcode 0x%x, data %u, ddp'ed, "
				"itt 0x%x.\n",
				skb,
				tcp_conn->in.hdr->opcode & ISCSI_OPCODE_MASK,
				tcp_conn->in.datalen,
				ntohl(tcp_conn->in.hdr->itt));
		offloaded = 1;
	} else {
		cxgb3i_rx_debug("skb 0x%p, opcode 0x%x, data %u, NOT ddp'ed, "
				"itt 0x%x.\n",
				skb,
				tcp_conn->in.hdr->opcode & ISCSI_OPCODE_MASK,
				tcp_conn->in.datalen,
				ntohl(tcp_conn->in.hdr->itt));
		offset += sizeof(struct cpl_iscsi_hdr_norss);
	}

	rc = read_pdu_skb(conn, skb, offset, offloaded);
	if (rc < 0)
		return rc;
	else
		return 0;
}

/*
 * pdu transmit, interact with libiscsi_tcp
 */
static inline void tx_skb_setmode(struct sk_buff *skb, int hcrc, int dcrc)
{
	u8 submode = 0;

	if (hcrc)
		submode |= 1;
	if (dcrc)
		submode |= 2;
	skb_ulp_mode(skb) = (ULP_MODE_ISCSI << 4) | submode;
}

void cxgb3i_conn_cleanup_task(struct iscsi_task *task)
{
	struct cxgb3i_task_data *tdata = task->dd_data +
					sizeof(struct iscsi_tcp_task);

	/* never reached the xmit task callout */
	if (tdata->skb)
		__kfree_skb(tdata->skb);
	memset(tdata, 0, sizeof(struct cxgb3i_task_data));

	/* MNC - Do we need a check in case this is called but
	 * cxgb3i_conn_alloc_pdu has never been called on the task */
	cxgb3i_release_itt(task, task->hdr_itt);
	iscsi_tcp_cleanup_task(task);
}

static int sgl_seek_offset(struct scatterlist *sgl, unsigned int sgcnt,
				unsigned int offset, unsigned int *off,
				struct scatterlist **sgp)
{
	int i;
	struct scatterlist *sg;

	for_each_sg(sgl, sg, sgcnt, i) {
		if (offset < sg->length) {
			*off = offset;
			*sgp = sg;
			return 0;
		}
		offset -= sg->length;
	}
	return -EFAULT;
}

static int sgl_read_to_frags(struct scatterlist *sg, unsigned int sgoffset,
				unsigned int dlen, skb_frag_t *frags,
				int frag_max)
{
	unsigned int datalen = dlen;
	unsigned int sglen = sg->length - sgoffset;
	struct page *page = sg_page(sg);
	int i;

	i = 0;
	do {
		unsigned int copy;

		if (!sglen) {
			sg = sg_next(sg);
			if (!sg) {
				cxgb3i_log_error("%s, sg NULL, len %u/%u.\n",
						 __func__, datalen, dlen);
				return -EINVAL;
			}
			sgoffset = 0;
			sglen = sg->length;
			page = sg_page(sg);

		}
		copy = min(datalen, sglen);
		if (i && page == frags[i - 1].page &&
		    sgoffset + sg->offset ==
			frags[i - 1].page_offset + frags[i - 1].size) {
			frags[i - 1].size += copy;
		} else {
			if (i >= frag_max) {
				cxgb3i_log_error("%s, too many pages %u, "
						 "dlen %u.\n", __func__,
						 frag_max, dlen);
				return -EINVAL;
			}

			frags[i].page = page;
			frags[i].page_offset = sg->offset + sgoffset;
			frags[i].size = copy;
			i++;
		}
		datalen -= copy;
		sgoffset += copy;
		sglen -= copy;
	} while (datalen);

	return i;
}

int cxgb3i_conn_alloc_pdu(struct iscsi_task *task, u8 opcode)
{
	struct iscsi_conn *conn = task->conn;
	struct iscsi_tcp_task *tcp_task = task->dd_data;
	struct cxgb3i_task_data *tdata = task->dd_data + sizeof(*tcp_task);
	struct scsi_cmnd *sc = task->sc;
	int headroom = SKB_TX_PDU_HEADER_LEN;

	tcp_task->dd_data = tdata;
	task->hdr = NULL;

	/* write command, need to send data pdus */
	if (skb_extra_headroom && (opcode == ISCSI_OP_SCSI_DATA_OUT ||
	    (opcode == ISCSI_OP_SCSI_CMD &&
	    (scsi_bidi_cmnd(sc) || sc->sc_data_direction == DMA_TO_DEVICE))))
		headroom += min(skb_extra_headroom, conn->max_xmit_dlength);

	tdata->skb = alloc_skb(TX_HEADER_LEN + headroom, GFP_ATOMIC);
	if (!tdata->skb)
		return -ENOMEM;
	skb_reserve(tdata->skb, TX_HEADER_LEN);

	cxgb3i_tx_debug("task 0x%p, opcode 0x%x, skb 0x%p.\n",
			task, opcode, tdata->skb);

	task->hdr = (struct iscsi_hdr *)tdata->skb->data;
	task->hdr_max = SKB_TX_PDU_HEADER_LEN;

	/* data_out uses scsi_cmd's itt */
	if (opcode != ISCSI_OP_SCSI_DATA_OUT)
		cxgb3i_reserve_itt(task, &task->hdr->itt);

	return 0;
}

int cxgb3i_conn_init_pdu(struct iscsi_task *task, unsigned int offset,
			      unsigned int count)
{
	struct iscsi_conn *conn = task->conn;
	struct iscsi_tcp_task *tcp_task = task->dd_data;
	struct cxgb3i_task_data *tdata = tcp_task->dd_data;
	struct sk_buff *skb = tdata->skb;
	unsigned int datalen = count;
	int i, padlen = iscsi_padding(count);
	struct page *pg;

	cxgb3i_tx_debug("task 0x%p,0x%p, offset %u, count %u, skb 0x%p.\n",
			task, task->sc, offset, count, skb);

	skb_put(skb, task->hdr_len);
	tx_skb_setmode(skb, conn->hdrdgst_en, datalen ? conn->datadgst_en : 0);
	if (!count)
		return 0;

	if (task->sc) {
		struct scsi_data_buffer *sdb = scsi_out(task->sc);
		struct scatterlist *sg = NULL;
		int err;

		tdata->offset = offset;
		tdata->count = count;
		err = sgl_seek_offset(sdb->table.sgl, sdb->table.nents,
					tdata->offset, &tdata->sgoffset, &sg);
		if (err < 0) {
			cxgb3i_log_warn("tpdu, sgl %u, bad offset %u/%u.\n",
					sdb->table.nents, tdata->offset,
					sdb->length);
			return err;
		}
		err = sgl_read_to_frags(sg, tdata->sgoffset, tdata->count,
					tdata->frags, MAX_PDU_FRAGS);
		if (err < 0) {
			cxgb3i_log_warn("tpdu, sgl %u, bad offset %u + %u.\n",
					sdb->table.nents, tdata->offset,
					tdata->count);
			return err;
		}
		tdata->nr_frags = err;

		if (tdata->nr_frags > MAX_SKB_FRAGS ||
		    (padlen && tdata->nr_frags == MAX_SKB_FRAGS)) {
			char *dst = skb->data + task->hdr_len;
			skb_frag_t *frag = tdata->frags;

			/* data fits in the skb's headroom */
			for (i = 0; i < tdata->nr_frags; i++, frag++) {
				char *src = kmap_atomic(frag->page,
							KM_SOFTIRQ0);

				memcpy(dst, src+frag->page_offset, frag->size);
				dst += frag->size;
				kunmap_atomic(src, KM_SOFTIRQ0);
			}
			if (padlen) {
				memset(dst, 0, padlen);
				padlen = 0;
			}
			skb_put(skb, count + padlen);
		} else {
			/* data fit into frag_list */
			for (i = 0; i < tdata->nr_frags; i++)
				get_page(tdata->frags[i].page);

			memcpy(skb_shinfo(skb)->frags, tdata->frags,
				sizeof(skb_frag_t) * tdata->nr_frags);
			skb_shinfo(skb)->nr_frags = tdata->nr_frags;
			skb->len += count;
			skb->data_len += count;
			skb->truesize += count;
		}

	} else {
		pg = virt_to_page(task->data);

		get_page(pg);
		skb_fill_page_desc(skb, 0, pg, offset_in_page(task->data),
					count);
		skb->len += count;
		skb->data_len += count;
		skb->truesize += count;
	}

	if (padlen) {
		i = skb_shinfo(skb)->nr_frags;
		get_page(pad_page);
		skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags, pad_page, 0,
				 padlen);

		skb->data_len += padlen;
		skb->truesize += padlen;
		skb->len += padlen;
	}

	return 0;
}

int cxgb3i_conn_xmit_pdu(struct iscsi_task *task)
{
	struct iscsi_tcp_conn *tcp_conn = task->conn->dd_data;
	struct cxgb3i_conn *cconn = tcp_conn->dd_data;
	struct iscsi_tcp_task *tcp_task = task->dd_data;
	struct cxgb3i_task_data *tdata = tcp_task->dd_data;
	struct sk_buff *skb = tdata->skb;
	unsigned int datalen;
	int err;

	if (!skb)
		return 0;

	datalen = skb->data_len;
	tdata->skb = NULL;
	err = cxgb3i_c3cn_send_pdus(cconn->cep->c3cn, skb);
	if (err > 0) {
		int pdulen = err;

	cxgb3i_tx_debug("task 0x%p, skb 0x%p, len %u/%u, rv %d.\n",
			task, skb, skb->len, skb->data_len, err);

		if (task->conn->hdrdgst_en)
			pdulen += ISCSI_DIGEST_SIZE;
		if (datalen && task->conn->datadgst_en)
			pdulen += ISCSI_DIGEST_SIZE;

		task->conn->txdata_octets += pdulen;
		return 0;
	}

	if (err < 0 && err != -EAGAIN) {
		kfree_skb(skb);
		cxgb3i_tx_debug("itt 0x%x, skb 0x%p, len %u/%u, xmit err %d.\n",
				task->itt, skb, skb->len, skb->data_len, err);
		iscsi_conn_printk(KERN_ERR, task->conn, "xmit err %d.\n", err);
		iscsi_conn_failure(task->conn, ISCSI_ERR_XMIT_FAILED);
		return err;
	}
	/* reset skb to send when we are called again */
	tdata->skb = skb;
	return -EAGAIN;
}

int cxgb3i_pdu_init(void)
{
	if (SKB_TX_HEADROOM > (512 * MAX_SKB_FRAGS))
		skb_extra_headroom = SKB_TX_HEADROOM;
	pad_page = alloc_page(GFP_KERNEL);
	if (!pad_page)
		return -ENOMEM;
	memset(page_address(pad_page), 0, PAGE_SIZE);
	return 0;
}

void cxgb3i_pdu_cleanup(void)
{
	if (pad_page) {
		__free_page(pad_page);
		pad_page = NULL;
	}
}

void cxgb3i_conn_pdu_ready(struct s3_conn *c3cn)
{
	struct sk_buff *skb;
	unsigned int read = 0;
	struct iscsi_conn *conn = c3cn->user_data;
	int err = 0;

	cxgb3i_rx_debug("cn 0x%p.\n", c3cn);

	read_lock(&c3cn->callback_lock);
	if (unlikely(!conn || conn->suspend_rx)) {
		cxgb3i_rx_debug("conn 0x%p, id %d, suspend_rx %lu!\n",
				conn, conn ? conn->id : 0xFF,
				conn ? conn->suspend_rx : 0xFF);
		read_unlock(&c3cn->callback_lock);
		return;
	}
	skb = skb_peek(&c3cn->receive_queue);
	while (!err && skb) {
		__skb_unlink(skb, &c3cn->receive_queue);
		read += skb_rx_pdulen(skb);
		cxgb3i_rx_debug("conn 0x%p, cn 0x%p, rx skb 0x%p, pdulen %u.\n",
				conn, c3cn, skb, skb_rx_pdulen(skb));
		err = cxgb3i_conn_read_pdu_skb(conn, skb);
		__kfree_skb(skb);
		skb = skb_peek(&c3cn->receive_queue);
	}
	read_unlock(&c3cn->callback_lock);
	if (c3cn) {
		c3cn->copied_seq += read;
		cxgb3i_c3cn_rx_credits(c3cn, read);
	}
	conn->rxdata_octets += read;

	if (err) {
		cxgb3i_log_info("conn 0x%p rx failed err %d.\n", conn, err);
		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
	}
}

void cxgb3i_conn_tx_open(struct s3_conn *c3cn)
{
	struct iscsi_conn *conn = c3cn->user_data;

	cxgb3i_tx_debug("cn 0x%p.\n", c3cn);
	if (conn) {
		cxgb3i_tx_debug("cn 0x%p, cid %d.\n", c3cn, conn->id);
		scsi_queue_work(conn->session->host, &conn->xmitwork);
	}
}

void cxgb3i_conn_closing(struct s3_conn *c3cn)
{
	struct iscsi_conn *conn;

	read_lock(&c3cn->callback_lock);
	conn = c3cn->user_data;
	if (conn && c3cn->state != C3CN_STATE_ESTABLISHED)
		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
	read_unlock(&c3cn->callback_lock);
}