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C/C++ Source or Header  |  2008-12-24  |  3.1 KB  |  125 lines
  1. #ifndef _ASM_FUTEX_H
  2. #define _ASM_FUTEX_H
  3.  
  4. #include <linux/futex.h>
  5. #include <linux/uaccess.h>
  6. #include <asm/errno.h>
  7. #include <asm/system.h>
  8.  
  9. #define __futex_atomic_op1(insn, ret, oldval, uaddr, oparg) \
  10. do {                                    \
  11.     register unsigned long r8 __asm ("r8") = 0;            \
  12.     __asm__ __volatile__(                        \
  13.         "    mf;;                    \n"    \
  14.         "[1:] "    insn ";;                \n"    \
  15.         "    .xdata4 \"__ex_table\", 1b-., 2f-.    \n"    \
  16.         "[2:]"                            \
  17.         : "+r" (r8), "=r" (oldval)                \
  18.         : "r" (uaddr), "r" (oparg)                \
  19.         : "memory");                        \
  20.     ret = r8;                            \
  21. } while (0)
  22.  
  23. #define __futex_atomic_op2(insn, ret, oldval, uaddr, oparg) \
  24. do {                                    \
  25.     register unsigned long r8 __asm ("r8") = 0;            \
  26.     int val, newval;                        \
  27.     do {                                \
  28.         __asm__ __volatile__(                    \
  29.             "    mf;;                  \n"    \
  30.             "[1:]    ld4 %3=[%4];;              \n"    \
  31.             "    mov %2=%3              \n"    \
  32.                 insn    ";;              \n"    \
  33.             "    mov ar.ccv=%2;;              \n"    \
  34.             "[2:]    cmpxchg4.acq %1=[%4],%3,ar.ccv;;  \n"    \
  35.             "    .xdata4 \"__ex_table\", 1b-., 3f-.\n"    \
  36.             "    .xdata4 \"__ex_table\", 2b-., 3f-.\n"    \
  37.             "[3:]"                        \
  38.             : "+r" (r8), "=r" (val), "=&r" (oldval),    \
  39.                "=&r" (newval)                \
  40.             : "r" (uaddr), "r" (oparg)            \
  41.             : "memory");                    \
  42.         if (unlikely (r8))                    \
  43.             break;                        \
  44.     } while (unlikely (val != oldval));                \
  45.     ret = r8;                            \
  46. } while (0)
  47.  
  48. static inline int
  49. futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
  50. {
  51.     int op = (encoded_op >> 28) & 7;
  52.     int cmp = (encoded_op >> 24) & 15;
  53.     int oparg = (encoded_op << 8) >> 20;
  54.     int cmparg = (encoded_op << 20) >> 20;
  55.     int oldval = 0, ret;
  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.     pagefault_disable();
  63.  
  64.     switch (op) {
  65.     case FUTEX_OP_SET:
  66.         __futex_atomic_op1("xchg4 %1=[%2],%3", ret, oldval, uaddr,
  67.                    oparg);
  68.         break;
  69.     case FUTEX_OP_ADD:
  70.         __futex_atomic_op2("add %3=%3,%5", ret, oldval, uaddr, oparg);
  71.         break;
  72.     case FUTEX_OP_OR:
  73.         __futex_atomic_op2("or %3=%3,%5", ret, oldval, uaddr, oparg);
  74.         break;
  75.     case FUTEX_OP_ANDN:
  76.         __futex_atomic_op2("and %3=%3,%5", ret, oldval, uaddr,
  77.                    ~oparg);
  78.         break;
  79.     case FUTEX_OP_XOR:
  80.         __futex_atomic_op2("xor %3=%3,%5", ret, oldval, uaddr, oparg);
  81.         break;
  82.     default:
  83.         ret = -ENOSYS;
  84.     }
  85.  
  86.     pagefault_enable();
  87.  
  88.     if (!ret) {
  89.         switch (cmp) {
  90.         case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
  91.         case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
  92.         case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
  93.         case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
  94.         case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
  95.         case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
  96.         default: ret = -ENOSYS;
  97.         }
  98.     }
  99.     return ret;
  100. }
  101.  
  102. static inline int
  103. futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
  104. {
  105.     if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
  106.         return -EFAULT;
  107.  
  108.     {
  109.         register unsigned long r8 __asm ("r8");
  110.         __asm__ __volatile__(
  111.             "    mf;;                    \n"
  112.             "    mov ar.ccv=%3;;                \n"
  113.             "[1:]    cmpxchg4.acq %0=[%1],%2,ar.ccv        \n"
  114.             "    .xdata4 \"__ex_table\", 1b-., 2f-.    \n"
  115.             "[2:]"
  116.             : "=r" (r8)
  117.             : "r" (uaddr), "r" (newval),
  118.               "rO" ((long) (unsigned) oldval)
  119.             : "memory");
  120.         return r8;
  121.     }
  122. }
  123.  
  124. #endif /* _ASM_FUTEX_H */
  125.