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0214c7f2 RSZ |
1 | /* |
2 | * drivers/staging/android/ion/ion_mem_pool.c | |
3 | * | |
4 | * Copyright (C) 2011 Google, Inc. | |
5 | * | |
6 | * This software is licensed under the terms of the GNU General Public | |
7 | * License version 2, as published by the Free Software Foundation, and | |
8 | * may be copied, distributed, and modified under those terms. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | */ | |
16 | ||
797a95c4 | 17 | #include <linux/debugfs.h> |
0214c7f2 RSZ |
18 | #include <linux/dma-mapping.h> |
19 | #include <linux/err.h> | |
797a95c4 | 20 | #include <linux/fs.h> |
0214c7f2 | 21 | #include <linux/list.h> |
30d79792 | 22 | #include <linux/init.h> |
0214c7f2 | 23 | #include <linux/slab.h> |
0cd2dc4d | 24 | #include <linux/swap.h> |
0214c7f2 RSZ |
25 | #include "ion_priv.h" |
26 | ||
0214c7f2 RSZ |
27 | static void *ion_page_pool_alloc_pages(struct ion_page_pool *pool) |
28 | { | |
29 | struct page *page = alloc_pages(pool->gfp_mask, pool->order); | |
30 | ||
31 | if (!page) | |
32 | return NULL; | |
0214c7f2 RSZ |
33 | return page; |
34 | } | |
35 | ||
36 | static void ion_page_pool_free_pages(struct ion_page_pool *pool, | |
37 | struct page *page) | |
38 | { | |
39 | __free_pages(page, pool->order); | |
40 | } | |
41 | ||
42 | static int ion_page_pool_add(struct ion_page_pool *pool, struct page *page) | |
43 | { | |
efee5a0c | 44 | mutex_lock(&pool->mutex); |
0fb9b815 | 45 | if (PageHighMem(page)) { |
38c003b1 | 46 | list_add_tail(&page->lru, &pool->high_items); |
0fb9b815 RSZ |
47 | pool->high_count++; |
48 | } else { | |
38c003b1 | 49 | list_add_tail(&page->lru, &pool->low_items); |
0fb9b815 RSZ |
50 | pool->low_count++; |
51 | } | |
efee5a0c | 52 | mutex_unlock(&pool->mutex); |
0214c7f2 RSZ |
53 | return 0; |
54 | } | |
55 | ||
0fb9b815 | 56 | static struct page *ion_page_pool_remove(struct ion_page_pool *pool, bool high) |
0214c7f2 | 57 | { |
0214c7f2 RSZ |
58 | struct page *page; |
59 | ||
0fb9b815 RSZ |
60 | if (high) { |
61 | BUG_ON(!pool->high_count); | |
38c003b1 | 62 | page = list_first_entry(&pool->high_items, struct page, lru); |
0fb9b815 RSZ |
63 | pool->high_count--; |
64 | } else { | |
65 | BUG_ON(!pool->low_count); | |
38c003b1 | 66 | page = list_first_entry(&pool->low_items, struct page, lru); |
0fb9b815 RSZ |
67 | pool->low_count--; |
68 | } | |
0214c7f2 | 69 | |
38c003b1 | 70 | list_del(&page->lru); |
0214c7f2 RSZ |
71 | return page; |
72 | } | |
73 | ||
79240748 | 74 | struct page *ion_page_pool_alloc(struct ion_page_pool *pool) |
0214c7f2 RSZ |
75 | { |
76 | struct page *page = NULL; | |
77 | ||
78 | BUG_ON(!pool); | |
79 | ||
80 | mutex_lock(&pool->mutex); | |
0fb9b815 RSZ |
81 | if (pool->high_count) |
82 | page = ion_page_pool_remove(pool, true); | |
83 | else if (pool->low_count) | |
84 | page = ion_page_pool_remove(pool, false); | |
0214c7f2 RSZ |
85 | mutex_unlock(&pool->mutex); |
86 | ||
0fb9b815 RSZ |
87 | if (!page) |
88 | page = ion_page_pool_alloc_pages(pool); | |
89 | ||
0214c7f2 RSZ |
90 | return page; |
91 | } | |
92 | ||
e1d855b0 | 93 | void ion_page_pool_free(struct ion_page_pool *pool, struct page *page) |
0214c7f2 RSZ |
94 | { |
95 | int ret; | |
96 | ||
bdeb9f1c HS |
97 | BUG_ON(pool->order != compound_order(page)); |
98 | ||
0214c7f2 RSZ |
99 | ret = ion_page_pool_add(pool, page); |
100 | if (ret) | |
101 | ion_page_pool_free_pages(pool, page); | |
0214c7f2 RSZ |
102 | } |
103 | ||
ea313b5f | 104 | static int ion_page_pool_total(struct ion_page_pool *pool, bool high) |
797a95c4 | 105 | { |
80cb77dc | 106 | int count = pool->low_count; |
797a95c4 | 107 | |
80cb77dc HS |
108 | if (high) |
109 | count += pool->high_count; | |
110 | ||
111 | return count << pool->order; | |
797a95c4 RSZ |
112 | } |
113 | ||
ea313b5f | 114 | int ion_page_pool_shrink(struct ion_page_pool *pool, gfp_t gfp_mask, |
679011bd | 115 | int nr_to_scan) |
0214c7f2 | 116 | { |
b44d9ce3 | 117 | int freed = 0; |
0fb9b815 RSZ |
118 | bool high; |
119 | ||
0cd2dc4d | 120 | if (current_is_kswapd()) |
17fbab1e | 121 | high = true; |
0cd2dc4d HS |
122 | else |
123 | high = !!(gfp_mask & __GFP_HIGHMEM); | |
0214c7f2 | 124 | |
797a95c4 | 125 | if (nr_to_scan == 0) |
ea313b5f RSZ |
126 | return ion_page_pool_total(pool, high); |
127 | ||
b44d9ce3 | 128 | while (freed < nr_to_scan) { |
ea313b5f RSZ |
129 | struct page *page; |
130 | ||
131 | mutex_lock(&pool->mutex); | |
ce3d1093 | 132 | if (pool->low_count) { |
ea313b5f | 133 | page = ion_page_pool_remove(pool, false); |
ce3d1093 CC |
134 | } else if (high && pool->high_count) { |
135 | page = ion_page_pool_remove(pool, true); | |
ea313b5f | 136 | } else { |
0fb9b815 | 137 | mutex_unlock(&pool->mutex); |
ea313b5f | 138 | break; |
0214c7f2 | 139 | } |
ea313b5f RSZ |
140 | mutex_unlock(&pool->mutex); |
141 | ion_page_pool_free_pages(pool, page); | |
b44d9ce3 | 142 | freed += (1 << pool->order); |
0214c7f2 | 143 | } |
0214c7f2 | 144 | |
b9daf0b6 | 145 | return freed; |
0214c7f2 RSZ |
146 | } |
147 | ||
e7f63771 CF |
148 | struct ion_page_pool *ion_page_pool_create(gfp_t gfp_mask, unsigned int order, |
149 | bool cached) | |
0214c7f2 | 150 | { |
8fb78ad6 BM |
151 | struct ion_page_pool *pool = kmalloc(sizeof(*pool), GFP_KERNEL); |
152 | ||
0214c7f2 RSZ |
153 | if (!pool) |
154 | return NULL; | |
0fb9b815 RSZ |
155 | pool->high_count = 0; |
156 | pool->low_count = 0; | |
157 | INIT_LIST_HEAD(&pool->low_items); | |
158 | INIT_LIST_HEAD(&pool->high_items); | |
bdeb9f1c | 159 | pool->gfp_mask = gfp_mask | __GFP_COMP; |
0214c7f2 RSZ |
160 | pool->order = order; |
161 | mutex_init(&pool->mutex); | |
797a95c4 | 162 | plist_node_init(&pool->list, order); |
e7f63771 CF |
163 | if (cached) |
164 | pool->cached = true; | |
0214c7f2 RSZ |
165 | |
166 | return pool; | |
167 | } | |
168 | ||
169 | void ion_page_pool_destroy(struct ion_page_pool *pool) | |
170 | { | |
0214c7f2 RSZ |
171 | kfree(pool); |
172 | } | |
173 | ||
797a95c4 RSZ |
174 | static int __init ion_page_pool_init(void) |
175 | { | |
797a95c4 RSZ |
176 | return 0; |
177 | } | |
30d79792 | 178 | device_initcall(ion_page_pool_init); |