xref: /freebsd/sys/dev/drm2/drm_scatter.c (revision b3e7694832e81d7a904a10f525f8797b753bf0d3)
1 /*-
2  * Copyright (c) 2009 Robert C. Noland III <rnoland@FreeBSD.org>
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
19  * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
22  * DEALINGS IN THE SOFTWARE.
23  */
24 
25 #include <sys/cdefs.h>
26 __FBSDID("$FreeBSD$");
27 
28 /** @file drm_scatter.c
29  * Allocation of memory for scatter-gather mappings by the graphics chip.
30  * The memory allocated here is then made into an aperture in the card
31  * by mapping the pages into the GART.
32  */
33 
34 #include <dev/drm2/drmP.h>
35 
36 #define DEBUG_SCATTER 0
37 
38 static inline void *drm_vmalloc_dma(vm_size_t size)
39 {
40 	return kmem_alloc_attr(size, M_NOWAIT | M_ZERO, 0,
41 	    BUS_SPACE_MAXADDR_32BIT, VM_MEMATTR_WRITE_COMBINING);
42 }
43 
44 void drm_sg_cleanup(struct drm_sg_mem * entry)
45 {
46 	if (entry == NULL)
47 		return;
48 
49 	if (entry->vaddr != NULL)
50 		kmem_free(entry->vaddr, IDX_TO_OFF(entry->pages));
51 
52 	free(entry->busaddr, DRM_MEM_SGLISTS);
53 	free(entry, DRM_MEM_DRIVER);
54 }
55 
56 int drm_sg_alloc(struct drm_device *dev, struct drm_scatter_gather * request)
57 {
58 	struct drm_sg_mem *entry;
59 	vm_size_t size;
60 	vm_pindex_t pindex;
61 
62 	DRM_DEBUG("\n");
63 
64 	if (!drm_core_check_feature(dev, DRIVER_SG))
65 		return -EINVAL;
66 
67 	if (dev->sg)
68 		return -EINVAL;
69 
70 	entry = malloc(sizeof(*entry), DRM_MEM_DRIVER, M_NOWAIT | M_ZERO);
71 	if (!entry)
72 		return -ENOMEM;
73 
74 	DRM_DEBUG("request size=%ld\n", request->size);
75 
76 	size = round_page(request->size);
77 	entry->pages = atop(size);
78 	entry->busaddr = malloc(entry->pages * sizeof(*entry->busaddr),
79 	    DRM_MEM_SGLISTS, M_NOWAIT | M_ZERO);
80 	if (!entry->busaddr) {
81 		free(entry, DRM_MEM_DRIVER);
82 		return -ENOMEM;
83 	}
84 
85 	entry->vaddr = drm_vmalloc_dma(size);
86 	if (entry->vaddr == NULL) {
87 		free(entry->busaddr, DRM_MEM_DRIVER);
88 		free(entry, DRM_MEM_DRIVER);
89 		return -ENOMEM;
90 	}
91 
92 	for (pindex = 0; pindex < entry->pages; pindex++) {
93 		entry->busaddr[pindex] =
94 		    vtophys((uintptr_t)entry->vaddr + IDX_TO_OFF(pindex));
95 	}
96 
97 	request->handle = (uintptr_t)entry->vaddr;
98 
99 	dev->sg = entry;
100 
101 	DRM_DEBUG("allocated %ju pages @ %p, contents=%08lx\n",
102 	    entry->pages, entry->vaddr, *(unsigned long *)entry->vaddr);
103 
104 	return 0;
105 }
106 
107 int drm_sg_alloc_ioctl(struct drm_device *dev, void *data,
108 		       struct drm_file *file_priv)
109 {
110 	struct drm_scatter_gather *request = data;
111 
112 	return drm_sg_alloc(dev, request);
113 
114 }
115 
116 int drm_sg_free(struct drm_device *dev, void *data,
117 		struct drm_file *file_priv)
118 {
119 	struct drm_scatter_gather *request = data;
120 	struct drm_sg_mem *entry;
121 
122 	if (!drm_core_check_feature(dev, DRIVER_SG))
123 		return -EINVAL;
124 
125 	entry = dev->sg;
126 	dev->sg = NULL;
127 
128 	if (!entry || (uintptr_t)entry->vaddr != request->handle)
129 		return -EINVAL;
130 
131 	DRM_DEBUG("free %p\n", entry->vaddr);
132 
133 	drm_sg_cleanup(entry);
134 
135 	return 0;
136 }
137