LXR linux/arch/powerpc/include/asm/futex.h

   1#ifndef _ASM_POWERPC_FUTEX_H
   2#define _ASM_POWERPC_FUTEX_H
   3
   4#ifdef __KERNEL__
   5
   6#include <linux/futex.h>
   7#include <linux/uaccess.h>
   8#include <asm/errno.h>
   9#include <asm/synch.h>
  10#include <asm/asm-compat.h>
  11
  12#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
  13  __asm__ __volatile ( \
  14        PPC_ATOMIC_ENTRY_BARRIER \
  15"1:     lwarx   %0,0,%2\n" \
  16        insn \
  17        PPC405_ERR77(0, %2) \
  18"2:     stwcx.  %1,0,%2\n" \
  19        "bne-   1b\n" \
  20        PPC_ATOMIC_EXIT_BARRIER \
  21        "li     %1,0\n" \
  22"3:     .section .fixup,\"ax\"\n" \
  23"4:     li      %1,%3\n" \
  24        "b      3b\n" \
  25        ".previous\n" \
  26        ".section __ex_table,\"a\"\n" \
  27        ".align 3\n" \
  28        PPC_LONG "1b,4b,2b,4b\n" \
  29        ".previous" \
  30        : "=&r" (oldval), "=&r" (ret) \
  31        : "b" (uaddr), "i" (-EFAULT), "r" (oparg) \
  32        : "cr0", "memory")
  33
  34static inline int futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
  35{
  36        int op = (encoded_op >> 28) & 7;
  37        int cmp = (encoded_op >> 24) & 15;
  38        int oparg = (encoded_op << 8) >> 20;
  39        int cmparg = (encoded_op << 20) >> 20;
  40        int oldval = 0, ret;
  41        if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
  42                oparg = 1 << oparg;
  43
  44        if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u32)))
  45                return -EFAULT;
  46
  47        pagefault_disable();
  48
  49        switch (op) {
  50        case FUTEX_OP_SET:
  51                __futex_atomic_op("mr %1,%4\n", ret, oldval, uaddr, oparg);
  52                break;
  53        case FUTEX_OP_ADD:
  54                __futex_atomic_op("add %1,%0,%4\n", ret, oldval, uaddr, oparg);
  55                break;
  56        case FUTEX_OP_OR:
  57                __futex_atomic_op("or %1,%0,%4\n", ret, oldval, uaddr, oparg);
  58                break;
  59        case FUTEX_OP_ANDN:
  60                __futex_atomic_op("andc %1,%0,%4\n", ret, oldval, uaddr, oparg);
  61                break;
  62        case FUTEX_OP_XOR:
  63                __futex_atomic_op("xor %1,%0,%4\n", ret, oldval, uaddr, oparg);
  64                break;
  65        default:
  66                ret = -ENOSYS;
  67        }
  68
  69        pagefault_enable();
  70
  71        if (!ret) {
  72                switch (cmp) {
  73                case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
  74                case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
  75                case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
  76                case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
  77                case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
  78                case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
  79                default: ret = -ENOSYS;
  80                }
  81        }
  82        return ret;
  83}
  84
  85static inline int
  86futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
  87                              u32 oldval, u32 newval)
  88{
  89        int ret = 0;
  90        u32 prev;
  91
  92        if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
  93                return -EFAULT;
  94
  95        __asm__ __volatile__ (
  96        PPC_ATOMIC_ENTRY_BARRIER
  97"1:     lwarx   %1,0,%3         # futex_atomic_cmpxchg_inatomic\n\
  98        cmpw    0,%1,%4\n\
  99        bne-    3f\n"
 100        PPC405_ERR77(0,%3)
 101"2:     stwcx.  %5,0,%3\n\
 102        bne-    1b\n"
 103        PPC_ATOMIC_EXIT_BARRIER
 104"3:     .section .fixup,\"ax\"\n\
 1054:      li      %0,%6\n\
 106        b       3b\n\
 107        .previous\n\
 108        .section __ex_table,\"a\"\n\
 109        .align 3\n\
 110        " PPC_LONG "1b,4b,2b,4b\n\
 111        .previous" \
 112        : "+r" (ret), "=&r" (prev), "+m" (*uaddr)
 113        : "r" (uaddr), "r" (oldval), "r" (newval), "i" (-EFAULT)
 114        : "cc", "memory");
 115
 116        *uval = prev;
 117        return ret;
 118}
 119
 120#endif /* __KERNEL__ */
 121#endif /* _ASM_POWERPC_FUTEX_H */
 122