1/*-
2 * Copyright (c) 2007-2008 Kip Macy <kmacy@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD$");
29
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/kernel.h>
33#include <sys/lock.h>
34#include <sys/malloc.h>
35#include <sys/mbuf.h>
36#include <sys/ktr.h>
37
38#include <vm/vm.h>
39#include <vm/pmap.h>
40
41#include <machine/bus.h>
42
43#include <cxgb_include.h>
44#include <sys/mvec.h>
45
46#ifdef INVARIANTS
47#define M_SANITY m_sanity
48#else
49#define M_SANITY(a, b)
50#endif
51
52int
53busdma_map_sg_collapse(bus_dma_tag_t tag, bus_dmamap_t map,
54	struct mbuf **m, bus_dma_segment_t *segs, int *nsegs)
55{
56	struct mbuf *n = *m;
57	int seg_count, defragged = 0, err = 0;
58	bus_dma_segment_t *psegs;
59
60	KASSERT(n->m_pkthdr.len, ("packet has zero header len"));
61	if (n->m_pkthdr.len <= PIO_LEN)
62		return (0);
63retry:
64	psegs = segs;
65	seg_count = 0;
66	if (n->m_next == NULL) {
67		busdma_map_mbuf_fast(tag, map, n, segs);
68		*nsegs = 1;
69		return (0);
70	}
71#if defined(__i386__) || defined(__amd64__)
72	while (n && seg_count < TX_MAX_SEGS) {
73		/*
74		 * firmware doesn't like empty segments
75		 */
76		if (__predict_true(n->m_len != 0)) {
77			seg_count++;
78			busdma_map_mbuf_fast(tag, map, n, psegs);
79			psegs++;
80		}
81		n = n->m_next;
82	}
83#else
84	err = bus_dmamap_load_mbuf_sg(tag, map, *m, segs, &seg_count, 0);
85#endif
86	if (seg_count == 0) {
87		if (cxgb_debug)
88			printf("empty segment chain\n");
89		err = EFBIG;
90		goto err_out;
91	}  else if (err == EFBIG || seg_count >= TX_MAX_SEGS) {
92		if (cxgb_debug)
93			printf("mbuf chain too long: %d max allowed %d\n",
94			    seg_count, TX_MAX_SEGS);
95		if (!defragged) {
96			n = m_defrag(*m, M_NOWAIT);
97			if (n == NULL) {
98				err = ENOBUFS;
99				goto err_out;
100			}
101			*m = n;
102			defragged = 1;
103			goto retry;
104		}
105		err = EFBIG;
106		goto err_out;
107	}
108
109	*nsegs = seg_count;
110err_out:
111	return (err);
112}
113
114void
115busdma_map_sg_vec(bus_dma_tag_t tag, bus_dmamap_t map,
116    struct mbuf *m, bus_dma_segment_t *segs, int *nsegs)
117{
118
119	for (*nsegs = 0; m != NULL ; segs++, *nsegs += 1, m = m->m_nextpkt)
120		busdma_map_mbuf_fast(tag, map, m, segs);
121}
122
123