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 13 #define __futex_atomic_op1(insn, ret, oldval, uaddr, oparg) \ 14 asm volatile("1:\t" insn "\n" \ 15 "2:\t.section .fixup,\"ax\"\n" \ 16 "3:\tmov\t%3, %1\n" \ 17 "\tjmp\t2b\n" \ 18 "\t.previous\n" \ 19 _ASM_EXTABLE(1b, 3b) \ 20 : "=r" (oldval), "=r" (ret), "+m" (*uaddr) \ 21 : "i" (-EFAULT), "0" (oparg), "1" (0)) 22 23 #define __futex_atomic_op2(insn, ret, oldval, uaddr, oparg) \ 24 asm volatile("1:\tmovl %2, %0\n" \ 25 "\tmovl\t%0, %3\n" \ 26 "\t" insn "\n" \ 27 "2:\t" LOCK_PREFIX "cmpxchgl %3, %2\n" \ 28 "\tjnz\t1b\n" \ 29 "3:\t.section .fixup,\"ax\"\n" \ 30 "4:\tmov\t%5, %1\n" \ 31 "\tjmp\t3b\n" \ 32 "\t.previous\n" \ 33 _ASM_EXTABLE(1b, 4b) \ 34 _ASM_EXTABLE(2b, 4b) \ 35 : "=&a" (oldval), "=&r" (ret), \ 36 "+m" (*uaddr), "=&r" (tem) \ 37 : "r" (oparg), "i" (-EFAULT), "1" (0)) 38 39 static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr) 40 { 41 int op = (encoded_op >> 28) & 7; 42 int cmp = (encoded_op >> 24) & 15; 43 int oparg = (encoded_op << 8) >> 20; 44 int cmparg = (encoded_op << 20) >> 20; 45 int oldval = 0, ret, tem; 46 47 if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) 48 oparg = 1 << oparg; 49 50 if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) 51 return -EFAULT; 52 53 #if defined(CONFIG_X86_32) && !defined(CONFIG_X86_BSWAP) 54 /* Real i386 machines can only support FUTEX_OP_SET */ 55 if (op != FUTEX_OP_SET && boot_cpu_data.x86 == 3) 56 return -ENOSYS; 57 #endif 58 59 pagefault_disable(); 60 61 switch (op) { 62 case FUTEX_OP_SET: 63 __futex_atomic_op1("xchgl %0, %2", ret, oldval, uaddr, oparg); 64 break; 65 case FUTEX_OP_ADD: 66 __futex_atomic_op1(LOCK_PREFIX "xaddl %0, %2", ret, oldval, 67 uaddr, oparg); 68 break; 69 case FUTEX_OP_OR: 70 __futex_atomic_op2("orl %4, %3", ret, oldval, uaddr, oparg); 71 break; 72 case FUTEX_OP_ANDN: 73 __futex_atomic_op2("andl %4, %3", ret, oldval, uaddr, ~oparg); 74 break; 75 case FUTEX_OP_XOR: 76 __futex_atomic_op2("xorl %4, %3", ret, oldval, uaddr, oparg); 77 break; 78 default: 79 ret = -ENOSYS; 80 } 81 82 pagefault_enable(); 83 84 if (!ret) { 85 switch (cmp) { 86 case FUTEX_OP_CMP_EQ: 87 ret = (oldval == cmparg); 88 break; 89 case FUTEX_OP_CMP_NE: 90 ret = (oldval != cmparg); 91 break; 92 case FUTEX_OP_CMP_LT: 93 ret = (oldval < cmparg); 94 break; 95 case FUTEX_OP_CMP_GE: 96 ret = (oldval >= cmparg); 97 break; 98 case FUTEX_OP_CMP_LE: 99 ret = (oldval <= cmparg); 100 break; 101 case FUTEX_OP_CMP_GT: 102 ret = (oldval > cmparg); 103 break; 104 default: 105 ret = -ENOSYS; 106 } 107 } 108 return ret; 109 } 110 111 static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, 112 u32 oldval, u32 newval) 113 { 114 int ret = 0; 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(u32))) 123 return -EFAULT; 124 125 asm volatile("1:\t" LOCK_PREFIX "cmpxchgl %4, %2\n" 126 "2:\t.section .fixup, \"ax\"\n" 127 "3:\tmov %3, %0\n" 128 "\tjmp 2b\n" 129 "\t.previous\n" 130 _ASM_EXTABLE(1b, 3b) 131 : "+r" (ret), "=a" (oldval), "+m" (*uaddr) 132 : "i" (-EFAULT), "r" (newval), "1" (oldval) 133 : "memory" 134 ); 135 136 *uval = oldval; 137 return ret; 138 } 139 140 #endif 141 #endif /* _ASM_X86_FUTEX_H */ 142