1 /*-
2 * Copyright 2003 Eric Anholt.
3 * All Rights Reserved.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice (including the next
13 * paragraph) shall be included in all copies or substantial portions of the
14 * Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19 * AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
21 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
22 */
23
24 #include <sys/cdefs.h>
25 __FBSDID("$FreeBSD: stable/9/sys/dev/drm/drm_pci.c 190565 2009-03-30 18:01:42Z rnoland $");
26
27 /**
28 * \file drm_pci.h
29 * \brief PCI consistent, DMA-accessible memory allocation.
30 *
31 * \author Eric Anholt <anholt@FreeBSD.org>
32 */
33
34 #include "dev/drm/drmP.h"
35
36 /**********************************************************************/
37 /** \name PCI memory */
38 /*@{*/
39
40 static void
drm_pci_busdma_callback(void * arg,bus_dma_segment_t * segs,int nsegs,int error)41 drm_pci_busdma_callback(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
42 {
43 drm_dma_handle_t *dmah = arg;
44
45 if (error != 0)
46 return;
47
48 KASSERT(nsegs == 1, ("drm_pci_busdma_callback: bad dma segment count"));
49 dmah->busaddr = segs[0].ds_addr;
50 }
51
52 /**
53 * \brief Allocate a physically contiguous DMA-accessible consistent
54 * memory block.
55 */
56 drm_dma_handle_t *
drm_pci_alloc(struct drm_device * dev,size_t size,size_t align,dma_addr_t maxaddr)57 drm_pci_alloc(struct drm_device *dev, size_t size,
58 size_t align, dma_addr_t maxaddr)
59 {
60 drm_dma_handle_t *dmah;
61 int ret;
62
63 /* Need power-of-two alignment, so fail the allocation if it isn't. */
64 if ((align & (align - 1)) != 0) {
65 DRM_ERROR("drm_pci_alloc with non-power-of-two alignment %d\n",
66 (int)align);
67 return NULL;
68 }
69
70 dmah = malloc(sizeof(drm_dma_handle_t), DRM_MEM_DMA, M_ZERO | M_NOWAIT);
71 if (dmah == NULL)
72 return NULL;
73
74 /* Make sure we aren't holding locks here */
75 mtx_assert(&dev->dev_lock, MA_NOTOWNED);
76 if (mtx_owned(&dev->dev_lock))
77 DRM_ERROR("called while holding dev_lock\n");
78 mtx_assert(&dev->dma_lock, MA_NOTOWNED);
79 if (mtx_owned(&dev->dma_lock))
80 DRM_ERROR("called while holding dma_lock\n");
81
82 ret = bus_dma_tag_create(NULL, align, 0, /* tag, align, boundary */
83 maxaddr, BUS_SPACE_MAXADDR, /* lowaddr, highaddr */
84 NULL, NULL, /* filtfunc, filtfuncargs */
85 size, 1, size, /* maxsize, nsegs, maxsegsize */
86 0, NULL, NULL, /* flags, lockfunc, lockfuncargs */
87 &dmah->tag);
88 if (ret != 0) {
89 free(dmah, DRM_MEM_DMA);
90 return NULL;
91 }
92
93 ret = bus_dmamem_alloc(dmah->tag, &dmah->vaddr,
94 BUS_DMA_WAITOK | BUS_DMA_ZERO | BUS_DMA_NOCACHE, &dmah->map);
95 if (ret != 0) {
96 bus_dma_tag_destroy(dmah->tag);
97 free(dmah, DRM_MEM_DMA);
98 return NULL;
99 }
100
101 ret = bus_dmamap_load(dmah->tag, dmah->map, dmah->vaddr, size,
102 drm_pci_busdma_callback, dmah, BUS_DMA_NOWAIT);
103 if (ret != 0) {
104 bus_dmamem_free(dmah->tag, dmah->vaddr, dmah->map);
105 bus_dma_tag_destroy(dmah->tag);
106 free(dmah, DRM_MEM_DMA);
107 return NULL;
108 }
109
110 return dmah;
111 }
112
113 /**
114 * \brief Free a DMA-accessible consistent memory block.
115 */
116 void
drm_pci_free(struct drm_device * dev,drm_dma_handle_t * dmah)117 drm_pci_free(struct drm_device *dev, drm_dma_handle_t *dmah)
118 {
119 if (dmah == NULL)
120 return;
121
122 bus_dmamem_free(dmah->tag, dmah->vaddr, dmah->map);
123 bus_dma_tag_destroy(dmah->tag);
124
125 free(dmah, DRM_MEM_DMA);
126 }
127
128 /*@}*/
129