]>
Commit | Line | Data |
---|---|---|
f2f45e5f JR |
1 | /* |
2 | * Copyright (C) 2008 Advanced Micro Devices, Inc. | |
3 | * | |
4 | * Author: Joerg Roedel <joerg.roedel@amd.com> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify it | |
7 | * under the terms of the GNU General Public License version 2 as published | |
8 | * by the Free Software Foundation. | |
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 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
18 | */ | |
19 | ||
20 | #include <linux/dma-debug.h> | |
30dfa90c | 21 | #include <linux/spinlock.h> |
f2f45e5f JR |
22 | #include <linux/types.h> |
23 | #include <linux/list.h> | |
24 | ||
30dfa90c JR |
25 | #define HASH_SIZE 1024ULL |
26 | #define HASH_FN_SHIFT 13 | |
27 | #define HASH_FN_MASK (HASH_SIZE - 1) | |
28 | ||
f2f45e5f JR |
29 | enum { |
30 | dma_debug_single, | |
31 | dma_debug_page, | |
32 | dma_debug_sg, | |
33 | dma_debug_coherent, | |
34 | }; | |
35 | ||
36 | struct dma_debug_entry { | |
37 | struct list_head list; | |
38 | struct device *dev; | |
39 | int type; | |
40 | phys_addr_t paddr; | |
41 | u64 dev_addr; | |
42 | u64 size; | |
43 | int direction; | |
44 | int sg_call_ents; | |
45 | int sg_mapped_ents; | |
46 | }; | |
47 | ||
30dfa90c JR |
48 | struct hash_bucket { |
49 | struct list_head list; | |
50 | spinlock_t lock; | |
51 | } __cacheline_aligned_in_smp; | |
52 | ||
53 | /* Hash list to save the allocated dma addresses */ | |
54 | static struct hash_bucket dma_entry_hash[HASH_SIZE]; | |
3b1e79ed JR |
55 | /* List of pre-allocated dma_debug_entry's */ |
56 | static LIST_HEAD(free_entries); | |
57 | /* Lock for the list above */ | |
58 | static DEFINE_SPINLOCK(free_entries_lock); | |
59 | ||
60 | /* Global disable flag - will be set in case of an error */ | |
61 | static bool global_disable __read_mostly; | |
62 | ||
63 | static u32 num_free_entries; | |
64 | static u32 min_free_entries; | |
30dfa90c JR |
65 | |
66 | /* | |
67 | * Hash related functions | |
68 | * | |
69 | * Every DMA-API request is saved into a struct dma_debug_entry. To | |
70 | * have quick access to these structs they are stored into a hash. | |
71 | */ | |
72 | static int hash_fn(struct dma_debug_entry *entry) | |
73 | { | |
74 | /* | |
75 | * Hash function is based on the dma address. | |
76 | * We use bits 20-27 here as the index into the hash | |
77 | */ | |
78 | return (entry->dev_addr >> HASH_FN_SHIFT) & HASH_FN_MASK; | |
79 | } | |
80 | ||
81 | /* | |
82 | * Request exclusive access to a hash bucket for a given dma_debug_entry. | |
83 | */ | |
84 | static struct hash_bucket *get_hash_bucket(struct dma_debug_entry *entry, | |
85 | unsigned long *flags) | |
86 | { | |
87 | int idx = hash_fn(entry); | |
88 | unsigned long __flags; | |
89 | ||
90 | spin_lock_irqsave(&dma_entry_hash[idx].lock, __flags); | |
91 | *flags = __flags; | |
92 | return &dma_entry_hash[idx]; | |
93 | } | |
94 | ||
95 | /* | |
96 | * Give up exclusive access to the hash bucket | |
97 | */ | |
98 | static void put_hash_bucket(struct hash_bucket *bucket, | |
99 | unsigned long *flags) | |
100 | { | |
101 | unsigned long __flags = *flags; | |
102 | ||
103 | spin_unlock_irqrestore(&bucket->lock, __flags); | |
104 | } | |
105 | ||
106 | /* | |
107 | * Search a given entry in the hash bucket list | |
108 | */ | |
109 | static struct dma_debug_entry *hash_bucket_find(struct hash_bucket *bucket, | |
110 | struct dma_debug_entry *ref) | |
111 | { | |
112 | struct dma_debug_entry *entry; | |
113 | ||
114 | list_for_each_entry(entry, &bucket->list, list) { | |
115 | if ((entry->dev_addr == ref->dev_addr) && | |
116 | (entry->dev == ref->dev)) | |
117 | return entry; | |
118 | } | |
119 | ||
120 | return NULL; | |
121 | } | |
122 | ||
123 | /* | |
124 | * Add an entry to a hash bucket | |
125 | */ | |
126 | static void hash_bucket_add(struct hash_bucket *bucket, | |
127 | struct dma_debug_entry *entry) | |
128 | { | |
129 | list_add_tail(&entry->list, &bucket->list); | |
130 | } | |
131 | ||
132 | /* | |
133 | * Remove entry from a hash bucket list | |
134 | */ | |
135 | static void hash_bucket_del(struct dma_debug_entry *entry) | |
136 | { | |
137 | list_del(&entry->list); | |
138 | } | |
139 | ||
140 | /* | |
141 | * Wrapper function for adding an entry to the hash. | |
142 | * This function takes care of locking itself. | |
143 | */ | |
144 | static void add_dma_entry(struct dma_debug_entry *entry) | |
145 | { | |
146 | struct hash_bucket *bucket; | |
147 | unsigned long flags; | |
148 | ||
149 | bucket = get_hash_bucket(entry, &flags); | |
150 | hash_bucket_add(bucket, entry); | |
151 | put_hash_bucket(bucket, &flags); | |
152 | } | |
153 | ||
3b1e79ed JR |
154 | /* struct dma_entry allocator |
155 | * | |
156 | * The next two functions implement the allocator for | |
157 | * struct dma_debug_entries. | |
158 | */ | |
159 | static struct dma_debug_entry *dma_entry_alloc(void) | |
160 | { | |
161 | struct dma_debug_entry *entry = NULL; | |
162 | unsigned long flags; | |
163 | ||
164 | spin_lock_irqsave(&free_entries_lock, flags); | |
165 | ||
166 | if (list_empty(&free_entries)) { | |
167 | printk(KERN_ERR "DMA-API: debugging out of memory " | |
168 | "- disabling\n"); | |
169 | global_disable = true; | |
170 | goto out; | |
171 | } | |
172 | ||
173 | entry = list_entry(free_entries.next, struct dma_debug_entry, list); | |
174 | list_del(&entry->list); | |
175 | memset(entry, 0, sizeof(*entry)); | |
176 | ||
177 | num_free_entries -= 1; | |
178 | if (num_free_entries < min_free_entries) | |
179 | min_free_entries = num_free_entries; | |
180 | ||
181 | out: | |
182 | spin_unlock_irqrestore(&free_entries_lock, flags); | |
183 | ||
184 | return entry; | |
185 | } | |
186 | ||
187 | static void dma_entry_free(struct dma_debug_entry *entry) | |
188 | { | |
189 | unsigned long flags; | |
190 | ||
191 | /* | |
192 | * add to beginning of the list - this way the entries are | |
193 | * more likely cache hot when they are reallocated. | |
194 | */ | |
195 | spin_lock_irqsave(&free_entries_lock, flags); | |
196 | list_add(&entry->list, &free_entries); | |
197 | num_free_entries += 1; | |
198 | spin_unlock_irqrestore(&free_entries_lock, flags); | |
199 | } | |
200 |