1/*-
2 * Copyright (c) 2010-2011 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
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#include <sys/cdefs.h>
31__FBSDID("$FreeBSD$");
32
33#include <sys/param.h>
34#include <sys/bus.h>
35
36#include <machine/bus.h>
37
38#include "common/efx.h"
39
40#include "sfxge.h"
41
42static void
43sfxge_dma_cb(void *arg, bus_dma_segment_t *segs, int nseg, int error)
44{
45	bus_addr_t *addr;
46
47	addr = arg;
48
49	if (error) {
50		*addr = 0;
51		return;
52	}
53
54	*addr = segs[0].ds_addr;
55}
56
57int
58sfxge_dma_map_sg_collapse(bus_dma_tag_t tag, bus_dmamap_t map,
59    struct mbuf **mp, bus_dma_segment_t *segs, int *nsegs, int maxsegs)
60{
61	bus_dma_segment_t *psegs;
62	struct mbuf *m;
63	int seg_count;
64	int defragged;
65	int err;
66
67	m = *mp;
68	defragged = err = seg_count = 0;
69
70	KASSERT(m->m_pkthdr.len, ("packet has zero header length"));
71
72retry:
73	psegs = segs;
74	seg_count = 0;
75	if (m->m_next == NULL) {
76		sfxge_map_mbuf_fast(tag, map, m, segs);
77		*nsegs = 1;
78		return (0);
79	}
80#if defined(__i386__) || defined(__amd64__)
81	while (m && seg_count < maxsegs) {
82		/*
83		 * firmware doesn't like empty segments
84		 */
85		if (m->m_len != 0) {
86			seg_count++;
87			sfxge_map_mbuf_fast(tag, map, m, psegs);
88			psegs++;
89		}
90		m = m->m_next;
91	}
92#else
93	err = bus_dmamap_load_mbuf_sg(tag, map, *mp, segs, &seg_count, 0);
94#endif
95	if (seg_count == 0) {
96		err = EFBIG;
97		goto err_out;
98	} else if (err == EFBIG || seg_count >= maxsegs) {
99		if (!defragged) {
100			m = m_defrag(*mp, M_NOWAIT);
101			if (m == NULL) {
102				err = ENOBUFS;
103				goto err_out;
104			}
105			*mp = m;
106			defragged = 1;
107			goto retry;
108		}
109		err = EFBIG;
110		goto err_out;
111	}
112	*nsegs = seg_count;
113
114err_out:
115	return (err);
116}
117
118void
119sfxge_dma_free(efsys_mem_t *esmp)
120{
121
122	bus_dmamap_unload(esmp->esm_tag, esmp->esm_map);
123	bus_dmamem_free(esmp->esm_tag, esmp->esm_base, esmp->esm_map);
124	bus_dma_tag_destroy(esmp->esm_tag);
125
126	esmp->esm_addr = 0;
127	esmp->esm_base = NULL;
128}
129
130int
131sfxge_dma_alloc(struct sfxge_softc *sc, bus_size_t len, efsys_mem_t *esmp)
132{
133	void *vaddr;
134
135	/* Create the child DMA tag. */
136	if (bus_dma_tag_create(sc->parent_dma_tag, PAGE_SIZE, 0,
137	    MIN(0x3FFFFFFFFFFFUL, BUS_SPACE_MAXADDR), BUS_SPACE_MAXADDR, NULL,
138	    NULL, len, 1, len, 0, NULL, NULL, &esmp->esm_tag) != 0) {
139		device_printf(sc->dev, "Couldn't allocate txq DMA tag\n");
140		return (ENOMEM);
141	}
142
143	/* Allocate kernel memory. */
144	if (bus_dmamem_alloc(esmp->esm_tag, (void **)&vaddr,
145	    BUS_DMA_WAITOK | BUS_DMA_COHERENT | BUS_DMA_ZERO,
146	    &esmp->esm_map) != 0) {
147		device_printf(sc->dev, "Couldn't allocate DMA memory\n");
148		bus_dma_tag_destroy(esmp->esm_tag);
149		return (ENOMEM);
150	}
151
152	/* Load map into device memory. */
153	if (bus_dmamap_load(esmp->esm_tag, esmp->esm_map, vaddr, len,
154	    sfxge_dma_cb, &esmp->esm_addr, 0) != 0) {
155		device_printf(sc->dev, "Couldn't load DMA mapping\n");
156		bus_dmamem_free(esmp->esm_tag, esmp->esm_base, esmp->esm_map);
157		bus_dma_tag_destroy(esmp->esm_tag);
158		return (ENOMEM);
159	}
160
161	/*
162	 * The callback gets error information about the mapping
163	 * and will have set our vaddr to NULL if something went
164	 * wrong.
165	 */
166	if (vaddr == NULL)
167		return (ENOMEM);
168
169	esmp->esm_base = vaddr;
170
171	return (0);
172}
173
174void
175sfxge_dma_fini(struct sfxge_softc *sc)
176{
177
178	bus_dma_tag_destroy(sc->parent_dma_tag);
179}
180
181int
182sfxge_dma_init(struct sfxge_softc *sc)
183{
184
185	/* Create the parent dma tag. */
186	if (bus_dma_tag_create(bus_get_dma_tag(sc->dev),	/* parent */
187	    1, 0,			/* algnmnt, boundary */
188	    BUS_SPACE_MAXADDR,		/* lowaddr */
189	    BUS_SPACE_MAXADDR,		/* highaddr */
190	    NULL, NULL,			/* filter, filterarg */
191	    BUS_SPACE_MAXSIZE_32BIT,	/* maxsize */
192	    BUS_SPACE_UNRESTRICTED,	/* nsegments */
193	    BUS_SPACE_MAXSIZE_32BIT,	/* maxsegsize */
194	    0,				/* flags */
195	    NULL, NULL,			/* lock, lockarg */
196	    &sc->parent_dma_tag)) {
197		device_printf(sc->dev, "Cannot allocate parent DMA tag\n");
198		return (ENOMEM);
199	}
200
201	return (0);
202}
203