kernel/arch/sparc/include/asm/futex_64.h

   1 #ifndef _SPARC64_FUTEX_H
   2 #define _SPARC64_FUTEX_H
   3
   4 #include <linux/futex.h>
   5 #include <linux/uaccess.h>
   6 #include <asm/errno.h>
   7
   8 #define __futex_cas_op(insn, ret, oldval, uaddr, oparg) \
   9         __asm__ __volatile__(                           \
  10         "\n1:   lduwa   [%3] %%asi, %2\n"               \
  11         "       " insn "\n"                             \
  12         "2:     casa    [%3] %%asi, %2, %1\n"           \
  13         "       cmp     %2, %1\n"                       \
  14         "       bne,pn  %%icc, 1b\n"                    \
  15         "        mov    0, %0\n"                        \
  16         "3:\n"                                          \
  17         "       .section .fixup,#alloc,#execinstr\n"    \
  18         "       .align  4\n"                            \
  19         "4:     sethi   %%hi(3b), %0\n"                 \
  20         "       jmpl    %0 + %%lo(3b), %%g0\n"          \
  21         "        mov    %5, %0\n"                       \
  22         "       .previous\n"                            \
  23         "       .section __ex_table,\"a\"\n"            \
  24         "       .align  4\n"                            \
  25         "       .word   1b, 4b\n"                       \
  26         "       .word   2b, 4b\n"                       \
  27         "       .previous\n"                            \
  28         : "=&r" (ret), "=&r" (oldval), "=&r" (tem)      \
  29         : "r" (uaddr), "r" (oparg), "i" (-EFAULT)       \
  30         : "memory")
  31
  32 static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr)
  33 {
  34         int op = (encoded_op >> 28) & 7;
  35         int cmp = (encoded_op >> 24) & 15;
  36         int oparg = (encoded_op << 8) >> 20;
  37         int cmparg = (encoded_op << 20) >> 20;
  38         int oldval = 0, ret, tem;
  39
  40         if (unlikely(!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))))
  41                 return -EFAULT;
  42         if (unlikely((((unsigned long) uaddr) & 0x3UL)))
  43                 return -EINVAL;
  44
  45         if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
  46                 oparg = 1 << oparg;
  47
  48         pagefault_disable();
  49
  50         switch (op) {
  51         case FUTEX_OP_SET:
  52                 __futex_cas_op("mov\t%4, %1", ret, oldval, uaddr, oparg);
  53                 break;
  54         case FUTEX_OP_ADD:
  55                 __futex_cas_op("add\t%2, %4, %1", ret, oldval, uaddr, oparg);
  56                 break;
  57         case FUTEX_OP_OR:
  58                 __futex_cas_op("or\t%2, %4, %1", ret, oldval, uaddr, oparg);
  59                 break;
  60         case FUTEX_OP_ANDN:
  61                 __futex_cas_op("andn\t%2, %4, %1", ret, oldval, uaddr, oparg);
  62                 break;
  63         case FUTEX_OP_XOR:
  64                 __futex_cas_op("xor\t%2, %4, %1", ret, oldval, uaddr, oparg);
  65                 break;
  66         default:
  67                 ret = -ENOSYS;
  68         }
  69
  70         pagefault_enable();
  71
  72         if (!ret) {
  73                 switch (cmp) {
  74                 case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
  75                 case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
  76                 case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
  77                 case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
  78                 case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
  79                 case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
  80                 default: ret = -ENOSYS;
  81                 }
  82         }
  83         return ret;
  84 }
  85
  86 static inline int
  87 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
  88                               u32 oldval, u32 newval)
  89 {
  90         int ret = 0;
  91
  92         __asm__ __volatile__(
  93         "\n1:   casa    [%4] %%asi, %3, %1\n"
  94         "2:\n"
  95         "       .section .fixup,#alloc,#execinstr\n"
  96         "       .align  4\n"
  97         "3:     sethi   %%hi(2b), %0\n"
  98         "       jmpl    %0 + %%lo(2b), %%g0\n"
  99         "       mov     %5, %0\n"
 100         "       .previous\n"
 101         "       .section __ex_table,\"a\"\n"
 102         "       .align  4\n"
 103         "       .word   1b, 3b\n"
 104         "       .previous\n"
 105         : "+r" (ret), "=r" (newval)
 106         : "1" (newval), "r" (oldval), "r" (uaddr), "i" (-EFAULT)
 107         : "memory");
 108
 109         *uval = newval;
 110         return ret;
 111 }
 112
 113 #endif /* !(_SPARC64_FUTEX_H) */