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19#include <linux/highmem.h>
20#include <asm/unaligned.h>
21
22#include "ctree.h"
23
24static inline u8 get_unaligned_le8(const void *p)
25{
26 return *(u8 *)p;
27}
28
29static inline void put_unaligned_le8(u8 val, void *p)
30{
31 *(u8 *)p = val;
32}
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51
52#define DEFINE_BTRFS_SETGET_BITS(bits) \
53u##bits btrfs_get_token_##bits(struct extent_buffer *eb, void *ptr, \
54 unsigned long off, \
55 struct btrfs_map_token *token) \
56{ \
57 unsigned long part_offset = (unsigned long)ptr; \
58 unsigned long offset = part_offset + off; \
59 void *p; \
60 int err; \
61 char *kaddr; \
62 unsigned long map_start; \
63 unsigned long map_len; \
64 int size = sizeof(u##bits); \
65 u##bits res; \
66 \
67 if (token && token->kaddr && token->offset <= offset && \
68 token->eb == eb && \
69 (token->offset + PAGE_SIZE >= offset + size)) { \
70 kaddr = token->kaddr; \
71 p = kaddr + part_offset - token->offset; \
72 res = get_unaligned_le##bits(p + off); \
73 return res; \
74 } \
75 err = map_private_extent_buffer(eb, offset, size, \
76 &kaddr, &map_start, &map_len); \
77 if (err) { \
78 __le##bits leres; \
79 \
80 read_extent_buffer(eb, &leres, offset, size); \
81 return le##bits##_to_cpu(leres); \
82 } \
83 p = kaddr + part_offset - map_start; \
84 res = get_unaligned_le##bits(p + off); \
85 if (token) { \
86 token->kaddr = kaddr; \
87 token->offset = map_start; \
88 token->eb = eb; \
89 } \
90 return res; \
91} \
92void btrfs_set_token_##bits(struct extent_buffer *eb, \
93 void *ptr, unsigned long off, u##bits val, \
94 struct btrfs_map_token *token) \
95{ \
96 unsigned long part_offset = (unsigned long)ptr; \
97 unsigned long offset = part_offset + off; \
98 void *p; \
99 int err; \
100 char *kaddr; \
101 unsigned long map_start; \
102 unsigned long map_len; \
103 int size = sizeof(u##bits); \
104 \
105 if (token && token->kaddr && token->offset <= offset && \
106 token->eb == eb && \
107 (token->offset + PAGE_SIZE >= offset + size)) { \
108 kaddr = token->kaddr; \
109 p = kaddr + part_offset - token->offset; \
110 put_unaligned_le##bits(val, p + off); \
111 return; \
112 } \
113 err = map_private_extent_buffer(eb, offset, size, \
114 &kaddr, &map_start, &map_len); \
115 if (err) { \
116 __le##bits val2; \
117 \
118 val2 = cpu_to_le##bits(val); \
119 write_extent_buffer(eb, &val2, offset, size); \
120 return; \
121 } \
122 p = kaddr + part_offset - map_start; \
123 put_unaligned_le##bits(val, p + off); \
124 if (token) { \
125 token->kaddr = kaddr; \
126 token->offset = map_start; \
127 token->eb = eb; \
128 } \
129}
130
131DEFINE_BTRFS_SETGET_BITS(8)
132DEFINE_BTRFS_SETGET_BITS(16)
133DEFINE_BTRFS_SETGET_BITS(32)
134DEFINE_BTRFS_SETGET_BITS(64)
135
136void btrfs_node_key(struct extent_buffer *eb,
137 struct btrfs_disk_key *disk_key, int nr)
138{
139 unsigned long ptr = btrfs_node_key_ptr_offset(nr);
140 read_eb_member(eb, (struct btrfs_key_ptr *)ptr,
141 struct btrfs_key_ptr, key, disk_key);
142}
143