xref: /freebsd/sys/dev/sfxge/sfxge_dma.c (revision 6137b5f7b8c183ee8806d79b3f1d8e5e3ddb3df3)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2010-2016 Solarflare Communications Inc.
5  * All rights reserved.
6  *
7  * This software was developed in part by Philip Paeps under contract for
8  * Solarflare Communications, Inc.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions are met:
12  *
13  * 1. Redistributions of source code must retain the above copyright notice,
14  *    this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright notice,
16  *    this list of conditions and the following disclaimer in the documentation
17  *    and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
20  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
21  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
24  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
26  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
27  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
28  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
29  * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  *
31  * The views and conclusions contained in the software and documentation are
32  * those of the authors and should not be interpreted as representing official
33  * policies, either expressed or implied, of the FreeBSD Project.
34  */
35 
36 #include <sys/param.h>
37 #include <sys/bus.h>
38 #include <sys/kernel.h>
39 #include <sys/malloc.h>
40 #include <sys/queue.h>
41 #include <sys/taskqueue.h>
42 
43 #include <machine/bus.h>
44 
45 #include "common/efx.h"
46 
47 #include "sfxge.h"
48 
49 static void
50 sfxge_dma_cb(void *arg, bus_dma_segment_t *segs, int nseg, int error)
51 {
52 	bus_addr_t *addr;
53 
54 	addr = arg;
55 
56 	if (error != 0) {
57 		*addr = 0;
58 		return;
59 	}
60 
61 	*addr = segs[0].ds_addr;
62 }
63 
64 int
65 sfxge_dma_map_sg_collapse(bus_dma_tag_t tag, bus_dmamap_t map,
66 			  struct mbuf **mp, bus_dma_segment_t *segs,
67 			  int *nsegs, int maxsegs)
68 {
69 	bus_dma_segment_t *psegs;
70 	struct mbuf *m;
71 	int seg_count;
72 	int defragged;
73 	int err;
74 
75 	m = *mp;
76 	defragged = err = seg_count = 0;
77 
78 	KASSERT(m->m_pkthdr.len, ("packet has zero header length"));
79 
80 retry:
81 	psegs = segs;
82 	seg_count = 0;
83 	if (m->m_next == NULL) {
84 		sfxge_map_mbuf_fast(tag, map, m, segs);
85 		*nsegs = 1;
86 		return (0);
87 	}
88 #if defined(__i386__) || defined(__amd64__)
89 	while (m != NULL && seg_count < maxsegs) {
90 		/*
91 		 * firmware doesn't like empty segments
92 		 */
93 		if (m->m_len != 0) {
94 			seg_count++;
95 			sfxge_map_mbuf_fast(tag, map, m, psegs);
96 			psegs++;
97 		}
98 		m = m->m_next;
99 	}
100 #else
101 	err = bus_dmamap_load_mbuf_sg(tag, map, *mp, segs, &seg_count, 0);
102 #endif
103 	if (seg_count == 0) {
104 		err = EFBIG;
105 		goto err_out;
106 	} else if (err == EFBIG || seg_count >= maxsegs) {
107 		if (!defragged) {
108 			m = m_defrag(*mp, M_NOWAIT);
109 			if (m == NULL) {
110 				err = ENOBUFS;
111 				goto err_out;
112 			}
113 			*mp = m;
114 			defragged = 1;
115 			goto retry;
116 		}
117 		err = EFBIG;
118 		goto err_out;
119 	}
120 	*nsegs = seg_count;
121 
122 err_out:
123 	return (err);
124 }
125 
126 void
127 sfxge_dma_free(efsys_mem_t *esmp)
128 {
129 
130 	bus_dmamap_unload(esmp->esm_tag, esmp->esm_map);
131 	bus_dmamem_free(esmp->esm_tag, esmp->esm_base, esmp->esm_map);
132 	bus_dma_tag_destroy(esmp->esm_tag);
133 
134 	esmp->esm_addr = 0;
135 	esmp->esm_base = NULL;
136 	esmp->esm_size = 0;
137 }
138 
139 int
140 sfxge_dma_alloc(struct sfxge_softc *sc, bus_size_t len, efsys_mem_t *esmp)
141 {
142 	void *vaddr;
143 
144 	/* Create the child DMA tag. */
145 	if (bus_dma_tag_create(sc->parent_dma_tag, PAGE_SIZE, 0,
146 	    MIN(0x3FFFFFFFFFFFUL, BUS_SPACE_MAXADDR), BUS_SPACE_MAXADDR, NULL,
147 	    NULL, len, 1, len, 0, NULL, NULL, &esmp->esm_tag) != 0) {
148 		device_printf(sc->dev, "Couldn't allocate txq DMA tag\n");
149 		goto fail_tag_create;
150 	}
151 
152 	/* Allocate kernel memory. */
153 	if (bus_dmamem_alloc(esmp->esm_tag, (void **)&vaddr,
154 	    BUS_DMA_WAITOK | BUS_DMA_COHERENT | BUS_DMA_ZERO,
155 	    &esmp->esm_map) != 0) {
156 		device_printf(sc->dev, "Couldn't allocate DMA memory\n");
157 		goto fail_alloc;
158 	}
159 
160 	/* Load map into device memory. */
161 	if (bus_dmamap_load(esmp->esm_tag, esmp->esm_map, vaddr, len,
162 	    sfxge_dma_cb, &esmp->esm_addr, 0) != 0) {
163 		device_printf(sc->dev, "Couldn't load DMA mapping\n");
164 		goto fail_load;
165 	}
166 
167 	/*
168 	 * The callback gets error information about the mapping
169 	 * and will have set esm_addr to 0 if something went
170 	 * wrong.
171 	 */
172 	if (esmp->esm_addr == 0)
173 		goto fail_load_check;
174 
175 	esmp->esm_base = vaddr;
176 	esmp->esm_size = len;
177 
178 	return (0);
179 
180 fail_load_check:
181 fail_load:
182 	bus_dmamem_free(esmp->esm_tag, vaddr, esmp->esm_map);
183 fail_alloc:
184 	bus_dma_tag_destroy(esmp->esm_tag);
185 fail_tag_create:
186 	return (ENOMEM);
187 }
188 
189 void
190 sfxge_dma_fini(struct sfxge_softc *sc)
191 {
192 
193 	bus_dma_tag_destroy(sc->parent_dma_tag);
194 }
195 
196 int
197 sfxge_dma_init(struct sfxge_softc *sc)
198 {
199 
200 	/* Create the parent dma tag. */
201 	if (bus_dma_tag_create(bus_get_dma_tag(sc->dev),	/* parent */
202 	    1, 0,			/* algnmnt, boundary */
203 	    BUS_SPACE_MAXADDR,		/* lowaddr */
204 	    BUS_SPACE_MAXADDR,		/* highaddr */
205 	    NULL, NULL,			/* filter, filterarg */
206 	    BUS_SPACE_MAXSIZE_32BIT,	/* maxsize */
207 	    BUS_SPACE_UNRESTRICTED,	/* nsegments */
208 	    BUS_SPACE_MAXSIZE_32BIT,	/* maxsegsize */
209 	    0,				/* flags */
210 	    NULL, NULL,			/* lock, lockarg */
211 	    &sc->parent_dma_tag) != 0) {
212 		device_printf(sc->dev, "Cannot allocate parent DMA tag\n");
213 		return (ENOMEM);
214 	}
215 
216 	return (0);
217 }
218