Root/drivers/gpu/drm/drm_scatter.c

1/**
2 * \file drm_scatter.c
3 * IOCTLs to manage scatter/gather memory
4 *
5 * \author Gareth Hughes <gareth@valinux.com>
6 */
7
8/*
9 * Created: Mon Dec 18 23:20:54 2000 by gareth@valinux.com
10 *
11 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
12 * All Rights Reserved.
13 *
14 * Permission is hereby granted, free of charge, to any person obtaining a
15 * copy of this software and associated documentation files (the "Software"),
16 * to deal in the Software without restriction, including without limitation
17 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
18 * and/or sell copies of the Software, and to permit persons to whom the
19 * Software is furnished to do so, subject to the following conditions:
20 *
21 * The above copyright notice and this permission notice (including the next
22 * paragraph) shall be included in all copies or substantial portions of the
23 * Software.
24 *
25 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
26 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
27 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
28 * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
29 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
30 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
31 * DEALINGS IN THE SOFTWARE.
32 */
33
34#include <linux/vmalloc.h>
35#include <linux/slab.h>
36#include "drmP.h"
37
38#define DEBUG_SCATTER 0
39
40static inline void *drm_vmalloc_dma(unsigned long size)
41{
42#if defined(__powerpc__) && defined(CONFIG_NOT_COHERENT_CACHE)
43    return __vmalloc(size, GFP_KERNEL, PAGE_KERNEL | _PAGE_NO_CACHE);
44#else
45    return vmalloc_32(size);
46#endif
47}
48
49void drm_sg_cleanup(struct drm_sg_mem * entry)
50{
51    struct page *page;
52    int i;
53
54    for (i = 0; i < entry->pages; i++) {
55        page = entry->pagelist[i];
56        if (page)
57            ClearPageReserved(page);
58    }
59
60    vfree(entry->virtual);
61
62    kfree(entry->busaddr);
63    kfree(entry->pagelist);
64    kfree(entry);
65}
66
67#ifdef _LP64
68# define ScatterHandle(x) (unsigned int)((x >> 32) + (x & ((1L << 32) - 1)))
69#else
70# define ScatterHandle(x) (unsigned int)(x)
71#endif
72
73int drm_sg_alloc(struct drm_device *dev, struct drm_scatter_gather * request)
74{
75    struct drm_sg_mem *entry;
76    unsigned long pages, i, j;
77
78    DRM_DEBUG("\n");
79
80    if (!drm_core_check_feature(dev, DRIVER_SG))
81        return -EINVAL;
82
83    if (dev->sg)
84        return -EINVAL;
85
86    entry = kzalloc(sizeof(*entry), GFP_KERNEL);
87    if (!entry)
88        return -ENOMEM;
89
90    pages = (request->size + PAGE_SIZE - 1) / PAGE_SIZE;
91    DRM_DEBUG("size=%ld pages=%ld\n", request->size, pages);
92
93    entry->pages = pages;
94    entry->pagelist = kcalloc(pages, sizeof(*entry->pagelist), GFP_KERNEL);
95    if (!entry->pagelist) {
96        kfree(entry);
97        return -ENOMEM;
98    }
99
100    entry->busaddr = kcalloc(pages, sizeof(*entry->busaddr), GFP_KERNEL);
101    if (!entry->busaddr) {
102        kfree(entry->pagelist);
103        kfree(entry);
104        return -ENOMEM;
105    }
106
107    entry->virtual = drm_vmalloc_dma(pages << PAGE_SHIFT);
108    if (!entry->virtual) {
109        kfree(entry->busaddr);
110        kfree(entry->pagelist);
111        kfree(entry);
112        return -ENOMEM;
113    }
114
115    /* This also forces the mapping of COW pages, so our page list
116     * will be valid. Please don't remove it...
117     */
118    memset(entry->virtual, 0, pages << PAGE_SHIFT);
119
120    entry->handle = ScatterHandle((unsigned long)entry->virtual);
121
122    DRM_DEBUG("handle = %08lx\n", entry->handle);
123    DRM_DEBUG("virtual = %p\n", entry->virtual);
124
125    for (i = (unsigned long)entry->virtual, j = 0; j < pages;
126         i += PAGE_SIZE, j++) {
127        entry->pagelist[j] = vmalloc_to_page((void *)i);
128        if (!entry->pagelist[j])
129            goto failed;
130        SetPageReserved(entry->pagelist[j]);
131    }
132
133    request->handle = entry->handle;
134
135    dev->sg = entry;
136
137#if DEBUG_SCATTER
138    /* Verify that each page points to its virtual address, and vice
139     * versa.
140     */
141    {
142        int error = 0;
143
144        for (i = 0; i < pages; i++) {
145            unsigned long *tmp;
146
147            tmp = page_address(entry->pagelist[i]);
148            for (j = 0;
149                 j < PAGE_SIZE / sizeof(unsigned long);
150                 j++, tmp++) {
151                *tmp = 0xcafebabe;
152            }
153            tmp = (unsigned long *)((u8 *) entry->virtual +
154                        (PAGE_SIZE * i));
155            for (j = 0;
156                 j < PAGE_SIZE / sizeof(unsigned long);
157                 j++, tmp++) {
158                if (*tmp != 0xcafebabe && error == 0) {
159                    error = 1;
160                    DRM_ERROR("Scatter allocation error, "
161                          "pagelist does not match "
162                          "virtual mapping\n");
163                }
164            }
165            tmp = page_address(entry->pagelist[i]);
166            for (j = 0;
167                 j < PAGE_SIZE / sizeof(unsigned long);
168                 j++, tmp++) {
169                *tmp = 0;
170            }
171        }
172        if (error == 0)
173            DRM_ERROR("Scatter allocation matches pagelist\n");
174    }
175#endif
176
177    return 0;
178
179      failed:
180    drm_sg_cleanup(entry);
181    return -ENOMEM;
182}
183
184int drm_sg_alloc_ioctl(struct drm_device *dev, void *data,
185               struct drm_file *file_priv)
186{
187    struct drm_scatter_gather *request = data;
188
189    return drm_sg_alloc(dev, request);
190
191}
192
193int drm_sg_free(struct drm_device *dev, void *data,
194        struct drm_file *file_priv)
195{
196    struct drm_scatter_gather *request = data;
197    struct drm_sg_mem *entry;
198
199    if (!drm_core_check_feature(dev, DRIVER_SG))
200        return -EINVAL;
201
202    entry = dev->sg;
203    dev->sg = NULL;
204
205    if (!entry || entry->handle != request->handle)
206        return -EINVAL;
207
208    DRM_DEBUG("virtual = %p\n", entry->virtual);
209
210    drm_sg_cleanup(entry);
211
212    return 0;
213}
214

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