1#ifndef _ASM_ARM_FUTEX_H 2#define _ASM_ARM_FUTEX_H 3 4#ifdef __KERNEL__ 5 6#ifdef CONFIG_SMP 7 8#include <asm-generic/futex.h> 9 10#else 11 12#include <linux/futex.h> 13#include <linux/preempt.h> 14#include <linux/uaccess.h> 15#include <asm/errno.h> 16 17#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \ 18 __asm__ __volatile__( \ 19 "1: ldrt %1, [%2]\n" \ 20 " " insn "\n" \ 21 "2: strt %0, [%2]\n" \ 22 " mov %0, #0\n" \ 23 "3:\n" \ 24 " .pushsection __ex_table,\"a\"\n" \ 25 " .align 3\n" \ 26 " .long 1b, 4f, 2b, 4f\n" \ 27 " .popsection\n" \ 28 " .pushsection .fixup,\"ax\"\n" \ 29 "4: mov %0, %4\n" \ 30 " b 3b\n" \ 31 " .popsection" \ 32 : "=&r" (ret), "=&r" (oldval) \ 33 : "r" (uaddr), "r" (oparg), "Ir" (-EFAULT) \ 34 : "cc", "memory") 35 36static inline int 37futex_atomic_op_inuser (int encoded_op, int __user *uaddr) 38{ 39 int op = (encoded_op >> 28) & 7; 40 int cmp = (encoded_op >> 24) & 15; 41 int oparg = (encoded_op << 8) >> 20; 42 int cmparg = (encoded_op << 20) >> 20; 43 int oldval = 0, ret; 44 45 if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) 46 oparg = 1 << oparg; 47 48 if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) 49 return -EFAULT; 50 51 pagefault_disable(); /* implies preempt_disable() */ 52 53 switch (op) { 54 case FUTEX_OP_SET: 55 __futex_atomic_op("mov %0, %3", ret, oldval, uaddr, oparg); 56 break; 57 case FUTEX_OP_ADD: 58 __futex_atomic_op("add %0, %1, %3", ret, oldval, uaddr, oparg); 59 break; 60 case FUTEX_OP_OR: 61 __futex_atomic_op("orr %0, %1, %3", ret, oldval, uaddr, oparg); 62 break; 63 case FUTEX_OP_ANDN: 64 __futex_atomic_op("and %0, %1, %3", ret, oldval, uaddr, ~oparg); 65 break; 66 case FUTEX_OP_XOR: 67 __futex_atomic_op("eor %0, %1, %3", ret, oldval, uaddr, oparg); 68 break; 69 default: 70 ret = -ENOSYS; 71 } 72 73 pagefault_enable(); /* subsumes preempt_enable() */ 74 75 if (!ret) { 76 switch (cmp) { 77 case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break; 78 case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break; 79 case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break; 80 case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break; 81 case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break; 82 case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break; 83 default: ret = -ENOSYS; 84 } 85 } 86 return ret; 87} 88 89static inline int 90futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval) 91{ 92 int val; 93 94 if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) 95 return -EFAULT; 96 97 pagefault_disable(); /* implies preempt_disable() */ 98 99 __asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n" 100 "1: ldrt %0, [%3]\n" 101 " teq %0, %1\n" 102 " it eq @ explicit IT needed for the 2b label\n" 103 "2: streqt %2, [%3]\n" 104 "3:\n" 105 " .pushsection __ex_table,\"a\"\n" 106 " .align 3\n" 107 " .long 1b, 4f, 2b, 4f\n" 108 " .popsection\n" 109 " .pushsection .fixup,\"ax\"\n" 110 "4: mov %0, %4\n" 111 " b 3b\n" 112 " .popsection" 113 : "=&r" (val) 114 : "r" (oldval), "r" (newval), "r" (uaddr), "Ir" (-EFAULT) 115 : "cc", "memory"); 116 117 pagefault_enable(); /* subsumes preempt_enable() */ 118 119 return val; 120} 121 122#endif /* !SMP */ 123 124#endif /* __KERNEL__ */ 125#endif /* _ASM_ARM_FUTEX_H */ 126