OMAPDSS: VENC: fix NULL pointer dereference in DSS2 VENC sysfs debug attr on OMAP4
[zen-stable.git] / drivers / gpu / drm / nouveau / nouveau_mm.c
blobb29ffb3d1408c6686f09c499c13e0d1a8f7fe05a
1 /*
2 * Copyright 2010 Red Hat Inc.
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20 * OTHER DEALINGS IN THE SOFTWARE.
22 * Authors: Ben Skeggs
25 #include "drmP.h"
26 #include "nouveau_drv.h"
27 #include "nouveau_mm.h"
29 static inline void
30 region_put(struct nouveau_mm *mm, struct nouveau_mm_node *a)
32 list_del(&a->nl_entry);
33 list_del(&a->fl_entry);
34 kfree(a);
37 static struct nouveau_mm_node *
38 region_split(struct nouveau_mm *mm, struct nouveau_mm_node *a, u32 size)
40 struct nouveau_mm_node *b;
42 if (a->length == size)
43 return a;
45 b = kmalloc(sizeof(*b), GFP_KERNEL);
46 if (unlikely(b == NULL))
47 return NULL;
49 b->offset = a->offset;
50 b->length = size;
51 b->type = a->type;
52 a->offset += size;
53 a->length -= size;
54 list_add_tail(&b->nl_entry, &a->nl_entry);
55 if (b->type == 0)
56 list_add_tail(&b->fl_entry, &a->fl_entry);
57 return b;
60 #define node(root, dir) ((root)->nl_entry.dir == &mm->nodes) ? NULL : \
61 list_entry((root)->nl_entry.dir, struct nouveau_mm_node, nl_entry)
63 void
64 nouveau_mm_put(struct nouveau_mm *mm, struct nouveau_mm_node *this)
66 struct nouveau_mm_node *prev = node(this, prev);
67 struct nouveau_mm_node *next = node(this, next);
69 list_add(&this->fl_entry, &mm->free);
70 this->type = 0;
72 if (prev && prev->type == 0) {
73 prev->length += this->length;
74 region_put(mm, this);
75 this = prev;
78 if (next && next->type == 0) {
79 next->offset = this->offset;
80 next->length += this->length;
81 region_put(mm, this);
85 int
86 nouveau_mm_get(struct nouveau_mm *mm, int type, u32 size, u32 size_nc,
87 u32 align, struct nouveau_mm_node **pnode)
89 struct nouveau_mm_node *prev, *this, *next;
90 u32 min = size_nc ? size_nc : size;
91 u32 align_mask = align - 1;
92 u32 splitoff;
93 u32 s, e;
95 list_for_each_entry(this, &mm->free, fl_entry) {
96 e = this->offset + this->length;
97 s = this->offset;
99 prev = node(this, prev);
100 if (prev && prev->type != type)
101 s = roundup(s, mm->block_size);
103 next = node(this, next);
104 if (next && next->type != type)
105 e = rounddown(e, mm->block_size);
107 s = (s + align_mask) & ~align_mask;
108 e &= ~align_mask;
109 if (s > e || e - s < min)
110 continue;
112 splitoff = s - this->offset;
113 if (splitoff && !region_split(mm, this, splitoff))
114 return -ENOMEM;
116 this = region_split(mm, this, min(size, e - s));
117 if (!this)
118 return -ENOMEM;
120 this->type = type;
121 list_del(&this->fl_entry);
122 *pnode = this;
123 return 0;
126 return -ENOSPC;
130 nouveau_mm_init(struct nouveau_mm *mm, u32 offset, u32 length, u32 block)
132 struct nouveau_mm_node *node;
134 if (block) {
135 mutex_init(&mm->mutex);
136 INIT_LIST_HEAD(&mm->nodes);
137 INIT_LIST_HEAD(&mm->free);
138 mm->block_size = block;
139 mm->heap_nodes = 0;
142 node = kzalloc(sizeof(*node), GFP_KERNEL);
143 if (!node)
144 return -ENOMEM;
145 node->offset = roundup(offset, mm->block_size);
146 node->length = rounddown(offset + length, mm->block_size) - node->offset;
148 list_add_tail(&node->nl_entry, &mm->nodes);
149 list_add_tail(&node->fl_entry, &mm->free);
150 mm->heap_nodes++;
151 return 0;
155 nouveau_mm_fini(struct nouveau_mm *mm)
157 struct nouveau_mm_node *node, *heap =
158 list_first_entry(&mm->nodes, struct nouveau_mm_node, nl_entry);
159 int nodes = 0;
161 list_for_each_entry(node, &mm->nodes, nl_entry) {
162 if (nodes++ == mm->heap_nodes) {
163 printk(KERN_ERR "nouveau_mm in use at destroy time!\n");
164 list_for_each_entry(node, &mm->nodes, nl_entry) {
165 printk(KERN_ERR "0x%02x: 0x%08x 0x%08x\n",
166 node->type, node->offset, node->length);
168 WARN_ON(1);
169 return -EBUSY;
173 kfree(heap);
174 return 0;