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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]; | |
55 | ||
56 | /* | |
57 | * Hash related functions | |
58 | * | |
59 | * Every DMA-API request is saved into a struct dma_debug_entry. To | |
60 | * have quick access to these structs they are stored into a hash. | |
61 | */ | |
62 | static int hash_fn(struct dma_debug_entry *entry) | |
63 | { | |
64 | /* | |
65 | * Hash function is based on the dma address. | |
66 | * We use bits 20-27 here as the index into the hash | |
67 | */ | |
68 | return (entry->dev_addr >> HASH_FN_SHIFT) & HASH_FN_MASK; | |
69 | } | |
70 | ||
71 | /* | |
72 | * Request exclusive access to a hash bucket for a given dma_debug_entry. | |
73 | */ | |
74 | static struct hash_bucket *get_hash_bucket(struct dma_debug_entry *entry, | |
75 | unsigned long *flags) | |
76 | { | |
77 | int idx = hash_fn(entry); | |
78 | unsigned long __flags; | |
79 | ||
80 | spin_lock_irqsave(&dma_entry_hash[idx].lock, __flags); | |
81 | *flags = __flags; | |
82 | return &dma_entry_hash[idx]; | |
83 | } | |
84 | ||
85 | /* | |
86 | * Give up exclusive access to the hash bucket | |
87 | */ | |
88 | static void put_hash_bucket(struct hash_bucket *bucket, | |
89 | unsigned long *flags) | |
90 | { | |
91 | unsigned long __flags = *flags; | |
92 | ||
93 | spin_unlock_irqrestore(&bucket->lock, __flags); | |
94 | } | |
95 | ||
96 | /* | |
97 | * Search a given entry in the hash bucket list | |
98 | */ | |
99 | static struct dma_debug_entry *hash_bucket_find(struct hash_bucket *bucket, | |
100 | struct dma_debug_entry *ref) | |
101 | { | |
102 | struct dma_debug_entry *entry; | |
103 | ||
104 | list_for_each_entry(entry, &bucket->list, list) { | |
105 | if ((entry->dev_addr == ref->dev_addr) && | |
106 | (entry->dev == ref->dev)) | |
107 | return entry; | |
108 | } | |
109 | ||
110 | return NULL; | |
111 | } | |
112 | ||
113 | /* | |
114 | * Add an entry to a hash bucket | |
115 | */ | |
116 | static void hash_bucket_add(struct hash_bucket *bucket, | |
117 | struct dma_debug_entry *entry) | |
118 | { | |
119 | list_add_tail(&entry->list, &bucket->list); | |
120 | } | |
121 | ||
122 | /* | |
123 | * Remove entry from a hash bucket list | |
124 | */ | |
125 | static void hash_bucket_del(struct dma_debug_entry *entry) | |
126 | { | |
127 | list_del(&entry->list); | |
128 | } | |
129 | ||
130 | /* | |
131 | * Wrapper function for adding an entry to the hash. | |
132 | * This function takes care of locking itself. | |
133 | */ | |
134 | static void add_dma_entry(struct dma_debug_entry *entry) | |
135 | { | |
136 | struct hash_bucket *bucket; | |
137 | unsigned long flags; | |
138 | ||
139 | bucket = get_hash_bucket(entry, &flags); | |
140 | hash_bucket_add(bucket, entry); | |
141 | put_hash_bucket(bucket, &flags); | |
142 | } | |
143 |