xref: /netbsd/sys/external/bsd/drm/dist/bsd-core/drm_pci.c (revision 6550d01e)
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 /**
25  * \file drm_pci.h
26  * \brief PCI consistent, DMA-accessible memory allocation.
27  *
28  * \author Eric Anholt <anholt@FreeBSD.org>
29  */
30 
31 #include "drmP.h"
32 
33 /**********************************************************************/
34 /** \name PCI memory */
35 /*@{*/
36 
37 #if defined(__FreeBSD__)
38 static void
39 drm_pci_busdma_callback(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
40 {
41 	drm_dma_handle_t *dmah = arg;
42 
43 	if (error != 0)
44 		return;
45 
46 	KASSERT(nsegs == 1, ("drm_pci_busdma_callback: bad dma segment count"));
47 	dmah->busaddr = segs[0].ds_addr;
48 }
49 #endif
50 
51 /**
52  * \brief Allocate a physically contiguous DMA-accessible consistent
53  * memory block.
54  */
55 drm_dma_handle_t *
56 drm_pci_alloc(struct drm_device *dev, size_t size,
57 	      size_t align, dma_addr_t maxaddr)
58 {
59 	drm_dma_handle_t *dmah;
60 	int ret;
61 #if defined (__NetBSD__)
62 	int nsegs;
63 #endif
64 
65 	/* Need power-of-two alignment, so fail the allocation if it isn't. */
66 	if ((align & (align - 1)) != 0) {
67 		DRM_ERROR("drm_pci_alloc with non-power-of-two alignment %d\n",
68 		    (int)align);
69 		return NULL;
70 	}
71 
72 	dmah = malloc(sizeof(drm_dma_handle_t), DRM_MEM_DMA, M_ZERO | M_NOWAIT);
73 	if (dmah == NULL)
74 		return NULL;
75 
76 #if defined__FreeBSD__
77 	/* Make sure we aren't holding locks here */
78 	mtx_assert(&dev->dev_lock, MA_NOTOWNED);
79 	if (mtx_owned(&dev->dev_lock))
80 	    DRM_ERROR("called while holding dev_lock\n");
81 	mtx_assert(&dev->dma_lock, MA_NOTOWNED);
82 	if (mtx_owned(&dev->dma_lock))
83 	    DRM_ERROR("called while holding dma_lock\n");
84 
85 	ret = bus_dma_tag_create(NULL, align, 0, /* tag, align, boundary */
86 	    maxaddr, BUS_SPACE_MAXADDR, /* lowaddr, highaddr */
87 	    NULL, NULL, /* filtfunc, filtfuncargs */
88 	    size, 1, size, /* maxsize, nsegs, maxsegsize */
89 	    0, NULL, NULL, /* flags, lockfunc, lockfuncargs */
90 	    &dmah->tag);
91 	if (ret != 0) {
92 		free(dmah, DRM_MEM_DMA);
93 		return NULL;
94 	}
95 
96 	ret = bus_dmamem_alloc(dmah->tag, &dmah->vaddr,
97 	    BUS_DMA_WAITOK | BUS_DMA_ZERO, &dmah->map);
98 	if (ret != 0) {
99 		bus_dma_tag_destroy(dmah->tag);
100 		free(dmah, DRM_MEM_DMA);
101 		return NULL;
102 	}
103 
104 	ret = bus_dmamap_load(dmah->tag, dmah->map, dmah->vaddr, size,
105 	    drm_pci_busdma_callback, dmah, BUS_DMA_NOWAIT | BUS_DMA_NOCACHE);
106 	if (ret != 0) {
107 		bus_dmamem_free(dmah->tag, dmah->vaddr, dmah->map);
108 		bus_dma_tag_destroy(dmah->tag);
109 		free(dmah, DRM_MEM_DMA);
110 		return NULL;
111 	}
112 #elif   defined(__NetBSD__)
113 	KASSERT(maxaddr >= 0xffffffffUL); /* no way to tell bus_dma_alloc */
114 	dmah->tag = dev->pa.pa_dmat; /* use 32-bit DMA tag */
115 
116 	if ((ret = bus_dmamem_alloc(dmah->tag, size, align, 0,
117 	    dmah->segs, 1, &nsegs, BUS_DMA_WAITOK)) != 0) {
118 		printf("drm: Unable to allocate %zu bytes of DMA, error %d\n",
119 		    size, ret);
120 		dmah->tag = NULL;
121 		free(dmah, DRM_MEM_DMA);
122 		return NULL;
123 	}
124 	/* XXX is there a better way to deal with this? */
125 	if (nsegs != 1) {
126 		printf("drm: bad segment count from bus_dmamem_alloc\n");
127 		bus_dmamem_free(dmah->tag, dmah->segs, 1);
128 		dmah->tag = NULL;
129 		free(dmah, DRM_MEM_DMA);
130 		return NULL;
131 	}
132 	if ((ret = bus_dmamem_map(dmah->tag, dmah->segs, nsegs, size,
133 	     &dmah->vaddr, BUS_DMA_NOWAIT | BUS_DMA_COHERENT | BUS_DMA_NOCACHE)) != 0) {
134 		printf("drm: Unable to map DMA, error %d\n", ret);
135 		bus_dmamem_free(dmah->tag, dmah->segs, 1);
136 		dmah->tag = NULL;
137 		free(dmah, DRM_MEM_DMA);
138 		return NULL;
139 	}
140 	if ((ret = bus_dmamap_create(dmah->tag, size, 1, size, 0,
141 	     BUS_DMA_NOWAIT, &dmah->map)) != 0) {
142 		printf("drm: Unable to create DMA map, error %d\n", ret);
143 		bus_dmamem_unmap(dmah->tag, dmah->vaddr, size);
144 		bus_dmamem_free(dmah->tag, dmah->segs, 1);
145 		dmah->tag = NULL;
146 		free(dmah, DRM_MEM_DMA);
147 		return NULL;
148 	}
149 	if ((ret = bus_dmamap_load(dmah->tag, dmah->map, dmah->vaddr,
150 	     size, NULL, BUS_DMA_NOWAIT | BUS_DMA_NOCACHE)) != 0) {
151 		printf("drm: Unable to load DMA map, error %d\n", ret);
152 		bus_dmamap_destroy(dmah->tag, dmah->map);
153 		bus_dmamem_unmap(dmah->tag, dmah->vaddr, size);
154 		bus_dmamem_free(dmah->tag, dmah->segs, 1);
155 		dmah->tag = NULL;
156 		free(dmah, DRM_MEM_DMA);
157 		return NULL;
158 	}
159 	dmah->busaddr = dmah->map->dm_segs[0].ds_addr;
160 	dmah->size = size;
161 	dmah->nsegs = 1;
162 	memset(dmah->vaddr, 0, size);
163 #endif
164 
165 	return dmah;
166 }
167 
168 /**
169  * \brief Free a DMA-accessible consistent memory block.
170  */
171 void
172 drm_pci_free(struct drm_device *dev, drm_dma_handle_t *dmah)
173 {
174 	if (dmah == NULL)
175 		return;
176 
177 #if defined(__FreeBSD__)
178 	bus_dmamem_free(dmah->tag, dmah->vaddr, dmah->map);
179 	bus_dma_tag_destroy(dmah->tag);
180 #elif   defined(__NetBSD__)
181 	bus_dmamap_unload(dmah->tag, dmah->map);
182 	bus_dmamap_destroy(dmah->tag, dmah->map);
183 	bus_dmamem_unmap(dmah->tag, dmah->vaddr, dmah->size);
184 	bus_dmamem_free(dmah->tag, dmah->segs, 1);
185 	dmah->tag = NULL;
186 #endif
187 
188 	free(dmah, DRM_MEM_DMA);
189 }
190 
191 /*@}*/
192