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