Thomas Gleixner | 2f18e47 | 2008-01-30 13:30:20 +0100 | [diff] [blame^] | 1 | #ifndef _ASM_X86_FUTEX_H |
| 2 | #define _ASM_X86_FUTEX_H |
| 3 | |
| 4 | #ifdef __KERNEL__ |
| 5 | |
| 6 | #include <linux/futex.h> |
| 7 | |
| 8 | #include <asm/asm.h> |
| 9 | #include <asm/errno.h> |
| 10 | #include <asm/processor.h> |
| 11 | #include <asm/system.h> |
| 12 | #include <asm/uaccess.h> |
| 13 | |
| 14 | #define __futex_atomic_op1(insn, ret, oldval, uaddr, oparg) \ |
| 15 | __asm__ __volatile( \ |
| 16 | "1: " insn "\n" \ |
| 17 | "2: .section .fixup,\"ax\"\n \ |
| 18 | 3: mov %3, %1\n \ |
| 19 | jmp 2b\n \ |
| 20 | .previous\n \ |
| 21 | .section __ex_table,\"a\"\n \ |
| 22 | .align 8\n" \ |
| 23 | _ASM_PTR "1b,3b\n \ |
| 24 | .previous" \ |
| 25 | : "=r" (oldval), "=r" (ret), "+m" (*uaddr) \ |
| 26 | : "i" (-EFAULT), "0" (oparg), "1" (0)) |
| 27 | |
| 28 | #define __futex_atomic_op2(insn, ret, oldval, uaddr, oparg) \ |
| 29 | __asm__ __volatile( \ |
| 30 | "1: movl %2, %0\n \ |
| 31 | movl %0, %3\n" \ |
| 32 | insn "\n" \ |
| 33 | "2: " LOCK_PREFIX "cmpxchgl %3, %2\n \ |
| 34 | jnz 1b\n \ |
| 35 | 3: .section .fixup,\"ax\"\n \ |
| 36 | 4: mov %5, %1\n \ |
| 37 | jmp 3b\n \ |
| 38 | .previous\n \ |
| 39 | .section __ex_table,\"a\"\n \ |
| 40 | .align 8\n" \ |
| 41 | _ASM_PTR "1b,4b,2b,4b\n \ |
| 42 | .previous" \ |
| 43 | : "=&a" (oldval), "=&r" (ret), "+m" (*uaddr), \ |
| 44 | "=&r" (tem) \ |
| 45 | : "r" (oparg), "i" (-EFAULT), "1" (0)) |
| 46 | |
| 47 | static inline int |
| 48 | futex_atomic_op_inuser(int encoded_op, int __user *uaddr) |
| 49 | { |
| 50 | int op = (encoded_op >> 28) & 7; |
| 51 | int cmp = (encoded_op >> 24) & 15; |
| 52 | int oparg = (encoded_op << 8) >> 20; |
| 53 | int cmparg = (encoded_op << 20) >> 20; |
| 54 | int oldval = 0, ret, tem; |
| 55 | |
| 56 | if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) |
| 57 | oparg = 1 << oparg; |
| 58 | |
| 59 | if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) |
| 60 | return -EFAULT; |
| 61 | |
| 62 | #if defined(CONFIG_X86_32) && !defined(CONFIG_X86_BSWAP) |
| 63 | /* Real i386 machines can only support FUTEX_OP_SET */ |
| 64 | if (op != FUTEX_OP_SET && boot_cpu_data.x86 == 3) |
| 65 | return -ENOSYS; |
| 66 | #endif |
| 67 | |
| 68 | pagefault_disable(); |
| 69 | |
| 70 | switch (op) { |
| 71 | case FUTEX_OP_SET: |
| 72 | __futex_atomic_op1("xchgl %0, %2", ret, oldval, uaddr, oparg); |
| 73 | break; |
| 74 | case FUTEX_OP_ADD: |
| 75 | __futex_atomic_op1(LOCK_PREFIX "xaddl %0, %2", ret, oldval, |
| 76 | uaddr, oparg); |
| 77 | break; |
| 78 | case FUTEX_OP_OR: |
| 79 | __futex_atomic_op2("orl %4, %3", ret, oldval, uaddr, oparg); |
| 80 | break; |
| 81 | case FUTEX_OP_ANDN: |
| 82 | __futex_atomic_op2("andl %4, %3", ret, oldval, uaddr, ~oparg); |
| 83 | break; |
| 84 | case FUTEX_OP_XOR: |
| 85 | __futex_atomic_op2("xorl %4, %3", ret, oldval, uaddr, oparg); |
| 86 | break; |
| 87 | default: |
| 88 | ret = -ENOSYS; |
| 89 | } |
| 90 | |
| 91 | pagefault_enable(); |
| 92 | |
| 93 | if (!ret) { |
| 94 | switch (cmp) { |
| 95 | case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break; |
| 96 | case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break; |
| 97 | case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break; |
| 98 | case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break; |
| 99 | case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break; |
| 100 | case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break; |
| 101 | default: ret = -ENOSYS; |
| 102 | } |
| 103 | } |
| 104 | return ret; |
| 105 | } |
| 106 | |
| 107 | static inline int |
| 108 | futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval) |
| 109 | { |
| 110 | if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) |
| 111 | return -EFAULT; |
| 112 | |
| 113 | __asm__ __volatile__( |
| 114 | "1: " LOCK_PREFIX "cmpxchgl %3, %1 \n" |
| 115 | |
| 116 | "2: .section .fixup, \"ax\" \n" |
| 117 | "3: mov %2, %0 \n" |
| 118 | " jmp 2b \n" |
| 119 | " .previous \n" |
| 120 | |
| 121 | " .section __ex_table, \"a\" \n" |
| 122 | " .align 8 \n" |
| 123 | _ASM_PTR " 1b,3b \n" |
| 124 | " .previous \n" |
| 125 | |
| 126 | : "=a" (oldval), "+m" (*uaddr) |
| 127 | : "i" (-EFAULT), "r" (newval), "0" (oldval) |
| 128 | : "memory" |
| 129 | ); |
| 130 | |
| 131 | return oldval; |
| 132 | } |
| 133 | |
| 134 | #endif |
Thomas Gleixner | 96a388d | 2007-10-11 11:20:03 +0200 | [diff] [blame] | 135 | #endif |