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 "drmP.h"
36
37#define DEBUG_SCATTER 0
38
39void drm_sg_cleanup(drm_sg_mem_t * entry)
40{
41	struct page *page;
42	int i;
43
44	for (i = 0; i < entry->pages; i++) {
45		page = entry->pagelist[i];
46		if (page)
47			ClearPageReserved(page);
48	}
49
50	vfree(entry->virtual);
51
52	drm_free(entry->busaddr,
53		 entry->pages * sizeof(*entry->busaddr), DRM_MEM_PAGES);
54	drm_free(entry->pagelist,
55		 entry->pages * sizeof(*entry->pagelist), DRM_MEM_PAGES);
56	drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
57}
58
59#ifdef _LP64
60# define ScatterHandle(x) (unsigned int)((x >> 32) + (x & ((1L << 32) - 1)))
61#else
62# define ScatterHandle(x) (unsigned int)(x)
63#endif
64
65int drm_sg_alloc(struct inode *inode, struct file *filp,
66		 unsigned int cmd, unsigned long arg)
67{
68	drm_file_t *priv = filp->private_data;
69	drm_device_t *dev = priv->head->dev;
70	drm_scatter_gather_t __user *argp = (void __user *)arg;
71	drm_scatter_gather_t request;
72	drm_sg_mem_t *entry;
73	unsigned long pages, i, j;
74
75	DRM_DEBUG("%s\n", __FUNCTION__);
76
77	if (!drm_core_check_feature(dev, DRIVER_SG))
78		return -EINVAL;
79
80	if (dev->sg)
81		return -EINVAL;
82
83	if (copy_from_user(&request, argp, sizeof(request)))
84		return -EFAULT;
85
86	entry = drm_alloc(sizeof(*entry), DRM_MEM_SGLISTS);
87	if (!entry)
88		return -ENOMEM;
89
90	memset(entry, 0, sizeof(*entry));
91
92	pages = (request.size + PAGE_SIZE - 1) / PAGE_SIZE;
93	DRM_DEBUG("sg size=%ld pages=%ld\n", request.size, pages);
94
95	entry->pages = pages;
96	entry->pagelist = drm_alloc(pages * sizeof(*entry->pagelist),
97				    DRM_MEM_PAGES);
98	if (!entry->pagelist) {
99		drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
100		return -ENOMEM;
101	}
102
103	memset(entry->pagelist, 0, pages * sizeof(*entry->pagelist));
104
105	entry->busaddr = drm_alloc(pages * sizeof(*entry->busaddr),
106				   DRM_MEM_PAGES);
107	if (!entry->busaddr) {
108		drm_free(entry->pagelist,
109			 entry->pages * sizeof(*entry->pagelist),
110			 DRM_MEM_PAGES);
111		drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
112		return -ENOMEM;
113	}
114	memset((void *)entry->busaddr, 0, pages * sizeof(*entry->busaddr));
115
116	entry->virtual = vmalloc_32(pages << PAGE_SHIFT);
117	if (!entry->virtual) {
118		drm_free(entry->busaddr,
119			 entry->pages * sizeof(*entry->busaddr), DRM_MEM_PAGES);
120		drm_free(entry->pagelist,
121			 entry->pages * sizeof(*entry->pagelist),
122			 DRM_MEM_PAGES);
123		drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
124		return -ENOMEM;
125	}
126
127	/* This also forces the mapping of COW pages, so our page list
128	 * will be valid.  Please don't remove it...
129	 */
130	memset(entry->virtual, 0, pages << PAGE_SHIFT);
131
132	entry->handle = ScatterHandle((unsigned long)entry->virtual);
133
134	DRM_DEBUG("sg alloc handle  = %08lx\n", entry->handle);
135	DRM_DEBUG("sg alloc virtual = %p\n", entry->virtual);
136
137	for (i = (unsigned long)entry->virtual, j = 0; j < pages;
138	     i += PAGE_SIZE, j++) {
139		entry->pagelist[j] = vmalloc_to_page((void *)i);
140		if (!entry->pagelist[j])
141			goto failed;
142		SetPageReserved(entry->pagelist[j]);
143	}
144
145	request.handle = entry->handle;
146
147	if (copy_to_user(argp, &request, sizeof(request))) {
148		drm_sg_cleanup(entry);
149		return -EFAULT;
150	}
151
152	dev->sg = entry;
153
154#if DEBUG_SCATTER
155	/* Verify that each page points to its virtual address, and vice
156	 * versa.
157	 */
158	{
159		int error = 0;
160
161		for (i = 0; i < pages; i++) {
162			unsigned long *tmp;
163
164			tmp = page_address(entry->pagelist[i]);
165			for (j = 0;
166			     j < PAGE_SIZE / sizeof(unsigned long);
167			     j++, tmp++) {
168				*tmp = 0xcafebabe;
169			}
170			tmp = (unsigned long *)((u8 *) entry->virtual +
171						(PAGE_SIZE * i));
172			for (j = 0;
173			     j < PAGE_SIZE / sizeof(unsigned long);
174			     j++, tmp++) {
175				if (*tmp != 0xcafebabe && error == 0) {
176					error = 1;
177					DRM_ERROR("Scatter allocation error, "
178						  "pagelist does not match "
179						  "virtual mapping\n");
180				}
181			}
182			tmp = page_address(entry->pagelist[i]);
183			for (j = 0;
184			     j < PAGE_SIZE / sizeof(unsigned long);
185			     j++, tmp++) {
186				*tmp = 0;
187			}
188		}
189		if (error == 0)
190			DRM_ERROR("Scatter allocation matches pagelist\n");
191	}
192#endif
193
194	return 0;
195
196      failed:
197	drm_sg_cleanup(entry);
198	return -ENOMEM;
199}
200
201int drm_sg_free(struct inode *inode, struct file *filp,
202		unsigned int cmd, unsigned long arg)
203{
204	drm_file_t *priv = filp->private_data;
205	drm_device_t *dev = priv->head->dev;
206	drm_scatter_gather_t request;
207	drm_sg_mem_t *entry;
208
209	if (!drm_core_check_feature(dev, DRIVER_SG))
210		return -EINVAL;
211
212	if (copy_from_user(&request,
213			   (drm_scatter_gather_t __user *) arg,
214			   sizeof(request)))
215		return -EFAULT;
216
217	entry = dev->sg;
218	dev->sg = NULL;
219
220	if (!entry || entry->handle != request.handle)
221		return -EINVAL;
222
223	DRM_DEBUG("sg free virtual  = %p\n", entry->virtual);
224
225	drm_sg_cleanup(entry);
226
227	return 0;
228}
229