xref: /dflybsd-src/sys/kern/subr_busdma.c (revision b320a7b1760a61b7b7da2e3aec2ed0716479d465)
1 /*
2  * Copyright (c) 2009 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Sepherosa Ziehau <sepherosa@gmail.com>
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  *
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
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/bus_dma.h>
38 
39 static void
40 _bus_dmamem_coherent_cb(void *arg, bus_dma_segment_t *segs, int nseg, int error)
41 {
42 	bus_addr_t *addr = arg;
43 
44 	if (error)
45 		return;
46 
47 	KASSERT(nseg == 1, ("too many DMA segments, %d should be 1", nseg));
48 	*addr = segs->ds_addr;
49 }
50 
51 int
52 bus_dmamem_coherent(bus_dma_tag_t parent,
53 		    bus_size_t alignment, bus_size_t boundary,
54 		    bus_addr_t lowaddr, bus_addr_t highaddr,
55 		    bus_size_t maxsize, int flags,
56 		    bus_dmamem_t *dmem)
57 {
58 	int error;
59 
60 	bzero(dmem, sizeof(*dmem));
61 
62 	error = bus_dma_tag_create(parent, alignment, boundary,
63 				   lowaddr, highaddr, NULL, NULL,
64 				   maxsize, 1, maxsize, 0,
65 				   &dmem->dmem_tag);
66 	if (error)
67 		return error;
68 
69         error = bus_dmamem_alloc(dmem->dmem_tag, &dmem->dmem_addr,
70 				 flags | BUS_DMA_COHERENT, &dmem->dmem_map);
71         if (error) {
72 		bus_dma_tag_destroy(dmem->dmem_tag);
73 		bzero(dmem, sizeof(*dmem));
74                 return error;
75 	}
76 
77 	error = bus_dmamap_load(dmem->dmem_tag, dmem->dmem_map,
78 				dmem->dmem_addr, maxsize,
79 				_bus_dmamem_coherent_cb, &dmem->dmem_busaddr,
80 				flags & BUS_DMA_NOWAIT);
81 	if (error) {
82 		if (error == EINPROGRESS) {
83 			panic("DMA coherent memory loading is still "
84 			      "in progress\n");
85 		}
86 		bus_dmamem_free(dmem->dmem_tag, dmem->dmem_addr,
87 				dmem->dmem_map);
88 		bus_dma_tag_destroy(dmem->dmem_tag);
89 		bzero(dmem, sizeof(*dmem));
90 		return error;
91 	}
92 	return 0;
93 }
94