xref: /freebsd-14.2/sys/dev/cxgb/sys/uipc_mvec.c (revision 685dc743)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2007-2008 Kip Macy <[email protected]>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
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 
52 int
busdma_map_sg_collapse(bus_dma_tag_t tag,bus_dmamap_t map,struct mbuf ** m,bus_dma_segment_t * segs,int * nsegs)53 busdma_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 
59 	KASSERT(n->m_pkthdr.len, ("packet has zero header len"));
60 	if (n->m_pkthdr.len <= PIO_LEN)
61 		return (0);
62 retry:
63 	seg_count = 0;
64 	err = bus_dmamap_load_mbuf_sg(tag, map, *m, segs, &seg_count, 0);
65 	if (seg_count == 0) {
66 		if (cxgb_debug)
67 			printf("empty segment chain\n");
68 		err = EFBIG;
69 		goto err_out;
70 	}  else if (err == EFBIG || seg_count >= TX_MAX_SEGS) {
71 		if (cxgb_debug)
72 			printf("mbuf chain too long: %d max allowed %d\n",
73 			    seg_count, TX_MAX_SEGS);
74 		if (!defragged) {
75 			n = m_defrag(*m, M_NOWAIT);
76 			if (n == NULL) {
77 				err = ENOBUFS;
78 				goto err_out;
79 			}
80 			*m = n;
81 			defragged = 1;
82 			goto retry;
83 		}
84 		err = EFBIG;
85 		goto err_out;
86 	}
87 
88 	*nsegs = seg_count;
89 err_out:
90 	return (err);
91 }
92 
93 void
busdma_map_sg_vec(bus_dma_tag_t tag,bus_dmamap_t map,struct mbuf * m,bus_dma_segment_t * segs,int * nsegs)94 busdma_map_sg_vec(bus_dma_tag_t tag, bus_dmamap_t map,
95     struct mbuf *m, bus_dma_segment_t *segs, int *nsegs)
96 {
97 	int n = 0;
98 
99 	for (*nsegs = 0; m != NULL; segs += n, *nsegs += n, m = m->m_nextpkt)
100 		bus_dmamap_load_mbuf_sg(tag, map, m, segs, &n, 0);
101 }
102 
103