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1965aae3 PA |
1 | #ifndef _ASM_X86_FUTEX_H |
2 | #define _ASM_X86_FUTEX_H | |
2f18e47c TG |
3 | |
4 | #ifdef __KERNEL__ | |
5 | ||
6 | #include <linux/futex.h> | |
730f412c | 7 | #include <linux/uaccess.h> |
2f18e47c TG |
8 | |
9 | #include <asm/asm.h> | |
10 | #include <asm/errno.h> | |
11 | #include <asm/processor.h> | |
63bcff2a | 12 | #include <asm/smap.h> |
2f18e47c TG |
13 | |
14 | #define __futex_atomic_op1(insn, ret, oldval, uaddr, oparg) \ | |
63bcff2a PA |
15 | asm volatile("\t" ASM_STAC "\n" \ |
16 | "1:\t" insn "\n" \ | |
17 | "2:\t" ASM_CLAC "\n" \ | |
18 | "\t.section .fixup,\"ax\"\n" \ | |
9407913f JP |
19 | "3:\tmov\t%3, %1\n" \ |
20 | "\tjmp\t2b\n" \ | |
21 | "\t.previous\n" \ | |
22 | _ASM_EXTABLE(1b, 3b) \ | |
23 | : "=r" (oldval), "=r" (ret), "+m" (*uaddr) \ | |
24 | : "i" (-EFAULT), "0" (oparg), "1" (0)) | |
2f18e47c TG |
25 | |
26 | #define __futex_atomic_op2(insn, ret, oldval, uaddr, oparg) \ | |
63bcff2a PA |
27 | asm volatile("\t" ASM_STAC "\n" \ |
28 | "1:\tmovl %2, %0\n" \ | |
9407913f JP |
29 | "\tmovl\t%0, %3\n" \ |
30 | "\t" insn "\n" \ | |
1f49a2c2 | 31 | "2:\t" LOCK_PREFIX "cmpxchgl %3, %2\n" \ |
9407913f | 32 | "\tjnz\t1b\n" \ |
63bcff2a PA |
33 | "3:\t" ASM_CLAC "\n" \ |
34 | "\t.section .fixup,\"ax\"\n" \ | |
9407913f JP |
35 | "4:\tmov\t%5, %1\n" \ |
36 | "\tjmp\t3b\n" \ | |
37 | "\t.previous\n" \ | |
38 | _ASM_EXTABLE(1b, 4b) \ | |
39 | _ASM_EXTABLE(2b, 4b) \ | |
40 | : "=&a" (oldval), "=&r" (ret), \ | |
41 | "+m" (*uaddr), "=&r" (tem) \ | |
42 | : "r" (oparg), "i" (-EFAULT), "1" (0)) | |
43 | ||
8d7718aa | 44 | static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr) |
2f18e47c TG |
45 | { |
46 | int op = (encoded_op >> 28) & 7; | |
47 | int cmp = (encoded_op >> 24) & 15; | |
48 | int oparg = (encoded_op << 8) >> 20; | |
49 | int cmparg = (encoded_op << 20) >> 20; | |
50 | int oldval = 0, ret, tem; | |
51 | ||
52 | if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) | |
53 | oparg = 1 << oparg; | |
54 | ||
8d7718aa | 55 | if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) |
2f18e47c TG |
56 | return -EFAULT; |
57 | ||
58 | #if defined(CONFIG_X86_32) && !defined(CONFIG_X86_BSWAP) | |
59 | /* Real i386 machines can only support FUTEX_OP_SET */ | |
60 | if (op != FUTEX_OP_SET && boot_cpu_data.x86 == 3) | |
61 | return -ENOSYS; | |
62 | #endif | |
63 | ||
64 | pagefault_disable(); | |
65 | ||
66 | switch (op) { | |
67 | case FUTEX_OP_SET: | |
68 | __futex_atomic_op1("xchgl %0, %2", ret, oldval, uaddr, oparg); | |
69 | break; | |
70 | case FUTEX_OP_ADD: | |
1f49a2c2 | 71 | __futex_atomic_op1(LOCK_PREFIX "xaddl %0, %2", ret, oldval, |
2f18e47c TG |
72 | uaddr, oparg); |
73 | break; | |
74 | case FUTEX_OP_OR: | |
75 | __futex_atomic_op2("orl %4, %3", ret, oldval, uaddr, oparg); | |
76 | break; | |
77 | case FUTEX_OP_ANDN: | |
78 | __futex_atomic_op2("andl %4, %3", ret, oldval, uaddr, ~oparg); | |
79 | break; | |
80 | case FUTEX_OP_XOR: | |
81 | __futex_atomic_op2("xorl %4, %3", ret, oldval, uaddr, oparg); | |
82 | break; | |
83 | default: | |
84 | ret = -ENOSYS; | |
85 | } | |
86 | ||
87 | pagefault_enable(); | |
88 | ||
89 | if (!ret) { | |
90 | switch (cmp) { | |
9407913f JP |
91 | case FUTEX_OP_CMP_EQ: |
92 | ret = (oldval == cmparg); | |
93 | break; | |
94 | case FUTEX_OP_CMP_NE: | |
95 | ret = (oldval != cmparg); | |
96 | break; | |
97 | case FUTEX_OP_CMP_LT: | |
98 | ret = (oldval < cmparg); | |
99 | break; | |
100 | case FUTEX_OP_CMP_GE: | |
101 | ret = (oldval >= cmparg); | |
102 | break; | |
103 | case FUTEX_OP_CMP_LE: | |
104 | ret = (oldval <= cmparg); | |
105 | break; | |
106 | case FUTEX_OP_CMP_GT: | |
107 | ret = (oldval > cmparg); | |
108 | break; | |
109 | default: | |
110 | ret = -ENOSYS; | |
2f18e47c TG |
111 | } |
112 | } | |
113 | return ret; | |
114 | } | |
115 | ||
8d7718aa ML |
116 | static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, |
117 | u32 oldval, u32 newval) | |
2f18e47c | 118 | { |
37a9d912 | 119 | int ret = 0; |
f18edc95 TG |
120 | |
121 | #if defined(CONFIG_X86_32) && !defined(CONFIG_X86_BSWAP) | |
122 | /* Real i386 machines have no cmpxchg instruction */ | |
123 | if (boot_cpu_data.x86 == 3) | |
124 | return -ENOSYS; | |
125 | #endif | |
126 | ||
8d7718aa | 127 | if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) |
2f18e47c TG |
128 | return -EFAULT; |
129 | ||
63bcff2a PA |
130 | asm volatile("\t" ASM_STAC "\n" |
131 | "1:\t" LOCK_PREFIX "cmpxchgl %4, %2\n" | |
132 | "2:\t" ASM_CLAC "\n" | |
133 | "\t.section .fixup, \"ax\"\n" | |
37a9d912 | 134 | "3:\tmov %3, %0\n" |
9407913f JP |
135 | "\tjmp 2b\n" |
136 | "\t.previous\n" | |
137 | _ASM_EXTABLE(1b, 3b) | |
37a9d912 ML |
138 | : "+r" (ret), "=a" (oldval), "+m" (*uaddr) |
139 | : "i" (-EFAULT), "r" (newval), "1" (oldval) | |
9407913f | 140 | : "memory" |
2f18e47c TG |
141 | ); |
142 | ||
37a9d912 ML |
143 | *uval = oldval; |
144 | return ret; | |
2f18e47c TG |
145 | } |
146 | ||
147 | #endif | |
1965aae3 | 148 | #endif /* _ASM_X86_FUTEX_H */ |