sfxge_dma.c revision 284555 
1/*-
2 * Copyright (c) 2010-2015 Solarflare Communications Inc.
3 * All rights reserved.
4 *
5 * This software was developed in part by Philip Paeps under contract for
6 * Solarflare Communications, Inc.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright notice,
12 *    this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright notice,
14 *    this list of conditions and the following disclaimer in the documentation
15 *    and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
18 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
19 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
20 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
21 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
22 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
23 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
24 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
25 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
26 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
27 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 *
29 * The views and conclusions contained in the software and documentation are
30 * those of the authors and should not be interpreted as representing official
31 * policies, either expressed or implied, of the FreeBSD Project.
32 */
33
34#include <sys/cdefs.h>
35__FBSDID("$FreeBSD: stable/10/sys/dev/sfxge/sfxge_dma.c 284555 2015-06-18 15:46:39Z arybchik $");
36
37#include <sys/param.h>
38#include <sys/bus.h>
39
40#include <machine/bus.h>
41
42#include "common/efx.h"
43
44#include "sfxge.h"
45
46static void
47sfxge_dma_cb(void *arg, bus_dma_segment_t *segs, int nseg, int error)
48{
49	bus_addr_t *addr;
50
51	addr = arg;
52
53	if (error != 0) {
54		*addr = 0;
55		return;
56	}
57
58	*addr = segs[0].ds_addr;
59}
60
61int
62sfxge_dma_map_sg_collapse(bus_dma_tag_t tag, bus_dmamap_t map,
63			  struct mbuf **mp, bus_dma_segment_t *segs,
64			  int *nsegs, int maxsegs)
65{
66	bus_dma_segment_t *psegs;
67	struct mbuf *m;
68	int seg_count;
69	int defragged;
70	int err;
71
72	m = *mp;
73	defragged = err = seg_count = 0;
74
75	KASSERT(m->m_pkthdr.len, ("packet has zero header length"));
76
77retry:
78	psegs = segs;
79	seg_count = 0;
80	if (m->m_next == NULL) {
81		sfxge_map_mbuf_fast(tag, map, m, segs);
82		*nsegs = 1;
83		return (0);
84	}
85#if defined(__i386__) || defined(__amd64__)
86	while (m != NULL && seg_count < maxsegs) {
87		/*
88		 * firmware doesn't like empty segments
89		 */
90		if (m->m_len != 0) {
91			seg_count++;
92			sfxge_map_mbuf_fast(tag, map, m, psegs);
93			psegs++;
94		}
95		m = m->m_next;
96	}
97#else
98	err = bus_dmamap_load_mbuf_sg(tag, map, *mp, segs, &seg_count, 0);
99#endif
100	if (seg_count == 0) {
101		err = EFBIG;
102		goto err_out;
103	} else if (err == EFBIG || seg_count >= maxsegs) {
104		if (!defragged) {
105			m = m_defrag(*mp, M_NOWAIT);
106			if (m == NULL) {
107				err = ENOBUFS;
108				goto err_out;
109			}
110			*mp = m;
111			defragged = 1;
112			goto retry;
113		}
114		err = EFBIG;
115		goto err_out;
116	}
117	*nsegs = seg_count;
118
119err_out:
120	return (err);
121}
122
123void
124sfxge_dma_free(efsys_mem_t *esmp)
125{
126
127	bus_dmamap_unload(esmp->esm_tag, esmp->esm_map);
128	bus_dmamem_free(esmp->esm_tag, esmp->esm_base, esmp->esm_map);
129	bus_dma_tag_destroy(esmp->esm_tag);
130
131	esmp->esm_addr = 0;
132	esmp->esm_base = NULL;
133}
134
135int
136sfxge_dma_alloc(struct sfxge_softc *sc, bus_size_t len, efsys_mem_t *esmp)
137{
138	void *vaddr;
139
140	/* Create the child DMA tag. */
141	if (bus_dma_tag_create(sc->parent_dma_tag, PAGE_SIZE, 0,
142	    MIN(0x3FFFFFFFFFFFUL, BUS_SPACE_MAXADDR), BUS_SPACE_MAXADDR, NULL,
143	    NULL, len, 1, len, 0, NULL, NULL, &esmp->esm_tag) != 0) {
144		device_printf(sc->dev, "Couldn't allocate txq DMA tag\n");
145		goto fail_tag_create;
146	}
147
148	/* Allocate kernel memory. */
149	if (bus_dmamem_alloc(esmp->esm_tag, (void **)&vaddr,
150	    BUS_DMA_WAITOK | BUS_DMA_COHERENT | BUS_DMA_ZERO,
151	    &esmp->esm_map) != 0) {
152		device_printf(sc->dev, "Couldn't allocate DMA memory\n");
153		goto fail_alloc;
154	}
155
156	/* Load map into device memory. */
157	if (bus_dmamap_load(esmp->esm_tag, esmp->esm_map, vaddr, len,
158	    sfxge_dma_cb, &esmp->esm_addr, 0) != 0) {
159		device_printf(sc->dev, "Couldn't load DMA mapping\n");
160		goto fail_load;
161	}
162
163	/*
164	 * The callback gets error information about the mapping
165	 * and will have set esm_addr to 0 if something went
166	 * wrong.
167	 */
168	if (esmp->esm_addr == 0)
169		goto fail_load_check;
170
171	esmp->esm_base = vaddr;
172
173	return (0);
174
175fail_load_check:
176fail_load:
177	bus_dmamem_free(esmp->esm_tag, vaddr, esmp->esm_map);
178fail_alloc:
179	bus_dma_tag_destroy(esmp->esm_tag);
180fail_tag_create:
181	return (ENOMEM);
182}
183
184void
185sfxge_dma_fini(struct sfxge_softc *sc)
186{
187
188	bus_dma_tag_destroy(sc->parent_dma_tag);
189}
190
191int
192sfxge_dma_init(struct sfxge_softc *sc)
193{
194
195	/* Create the parent dma tag. */
196	if (bus_dma_tag_create(bus_get_dma_tag(sc->dev),	/* parent */
197	    1, 0,			/* algnmnt, boundary */
198	    BUS_SPACE_MAXADDR,		/* lowaddr */
199	    BUS_SPACE_MAXADDR,		/* highaddr */
200	    NULL, NULL,			/* filter, filterarg */
201	    BUS_SPACE_MAXSIZE_32BIT,	/* maxsize */
202	    BUS_SPACE_UNRESTRICTED,	/* nsegments */
203	    BUS_SPACE_MAXSIZE_32BIT,	/* maxsegsize */
204	    0,				/* flags */
205	    NULL, NULL,			/* lock, lockarg */
206	    &sc->parent_dma_tag) != 0) {
207		device_printf(sc->dev, "Cannot allocate parent DMA tag\n");
208		return (ENOMEM);
209	}
210
211	return (0);
212}
213