xref: /freebsd/sys/dev/drm2/drm_scatter.c (revision 734e82fe33aa764367791a7d603b383996c6b40b)
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 /** @file drm_scatter.c
27  * Allocation of memory for scatter-gather mappings by the graphics chip.
28  * The memory allocated here is then made into an aperture in the card
29  * by mapping the pages into the GART.
30  */
31 
32 #include <dev/drm2/drmP.h>
33 
34 #define DEBUG_SCATTER 0
35 
36 static inline void *drm_vmalloc_dma(vm_size_t size)
37 {
38 	return kmem_alloc_attr(size, M_NOWAIT | M_ZERO, 0,
39 	    BUS_SPACE_MAXADDR_32BIT, VM_MEMATTR_WRITE_COMBINING);
40 }
41 
42 void drm_sg_cleanup(struct drm_sg_mem * entry)
43 {
44 	if (entry == NULL)
45 		return;
46 
47 	if (entry->vaddr != NULL)
48 		kmem_free(entry->vaddr, IDX_TO_OFF(entry->pages));
49 
50 	free(entry->busaddr, DRM_MEM_SGLISTS);
51 	free(entry, DRM_MEM_DRIVER);
52 }
53 
54 int drm_sg_alloc(struct drm_device *dev, struct drm_scatter_gather * request)
55 {
56 	struct drm_sg_mem *entry;
57 	vm_size_t size;
58 	vm_pindex_t pindex;
59 
60 	DRM_DEBUG("\n");
61 
62 	if (!drm_core_check_feature(dev, DRIVER_SG))
63 		return -EINVAL;
64 
65 	if (dev->sg)
66 		return -EINVAL;
67 
68 	entry = malloc(sizeof(*entry), DRM_MEM_DRIVER, M_NOWAIT | M_ZERO);
69 	if (!entry)
70 		return -ENOMEM;
71 
72 	DRM_DEBUG("request size=%ld\n", request->size);
73 
74 	size = round_page(request->size);
75 	entry->pages = atop(size);
76 	entry->busaddr = malloc(entry->pages * sizeof(*entry->busaddr),
77 	    DRM_MEM_SGLISTS, M_NOWAIT | M_ZERO);
78 	if (!entry->busaddr) {
79 		free(entry, DRM_MEM_DRIVER);
80 		return -ENOMEM;
81 	}
82 
83 	entry->vaddr = drm_vmalloc_dma(size);
84 	if (entry->vaddr == NULL) {
85 		free(entry->busaddr, DRM_MEM_DRIVER);
86 		free(entry, DRM_MEM_DRIVER);
87 		return -ENOMEM;
88 	}
89 
90 	for (pindex = 0; pindex < entry->pages; pindex++) {
91 		entry->busaddr[pindex] =
92 		    vtophys((uintptr_t)entry->vaddr + IDX_TO_OFF(pindex));
93 	}
94 
95 	request->handle = (uintptr_t)entry->vaddr;
96 
97 	dev->sg = entry;
98 
99 	DRM_DEBUG("allocated %ju pages @ %p, contents=%08lx\n",
100 	    entry->pages, entry->vaddr, *(unsigned long *)entry->vaddr);
101 
102 	return 0;
103 }
104 
105 int drm_sg_alloc_ioctl(struct drm_device *dev, void *data,
106 		       struct drm_file *file_priv)
107 {
108 	struct drm_scatter_gather *request = data;
109 
110 	return drm_sg_alloc(dev, request);
111 
112 }
113 
114 int drm_sg_free(struct drm_device *dev, void *data,
115 		struct drm_file *file_priv)
116 {
117 	struct drm_scatter_gather *request = data;
118 	struct drm_sg_mem *entry;
119 
120 	if (!drm_core_check_feature(dev, DRIVER_SG))
121 		return -EINVAL;
122 
123 	entry = dev->sg;
124 	dev->sg = NULL;
125 
126 	if (!entry || (uintptr_t)entry->vaddr != request->handle)
127 		return -EINVAL;
128 
129 	DRM_DEBUG("free %p\n", entry->vaddr);
130 
131 	drm_sg_cleanup(entry);
132 
133 	return 0;
134 }
135