kernel/arch/microblaze/include/asm/futex.h

   1 #ifndef _ASM_MICROBLAZE_FUTEX_H
   2 #define _ASM_MICROBLAZE_FUTEX_H
   3
   4 #ifdef __KERNEL__
   5
   6 #include <linux/futex.h>
   7 #include <linux/uaccess.h>
   8 #include <asm/errno.h>
   9
  10 #define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
  11 ({                                                                      \
  12         __asm__ __volatile__ (                                          \
  13                         "1:     lwx     %0, %2, r0; "                   \
  14                                 insn                                    \
  15                         "2:     swx     %1, %2, r0;                     \
  16                                 addic   %1, r0, 0;                      \
  17                                 bnei    %1, 1b;                         \
  18                         3:                                              \
  19                         .section .fixup,\"ax\";                         \
  20                         4:      brid    3b;                             \
  21                                 addik   %1, r0, %3;                     \
  22                         .previous;                                      \
  23                         .section __ex_table,\"a\";                      \
  24                         .word   1b,4b,2b,4b;                            \
  25                         .previous;"                                     \
  26         : "=&r" (oldval), "=&r" (ret)                                   \
  27         : "r" (uaddr), "i" (-EFAULT), "r" (oparg)                       \
  28         );                                                              \
  29 })
  30
  31 static inline int
  32 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;
  39         if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
  40                 oparg = 1 << oparg;
  41
  42         if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
  43                 return -EFAULT;
  44
  45         pagefault_disable();
  46
  47         switch (op) {
  48         case FUTEX_OP_SET:
  49                 __futex_atomic_op("or %1,%4,%4;", ret, oldval, uaddr, oparg);
  50                 break;
  51         case FUTEX_OP_ADD:
  52                 __futex_atomic_op("add %1,%0,%4;", ret, oldval, uaddr, oparg);
  53                 break;
  54         case FUTEX_OP_OR:
  55                 __futex_atomic_op("or %1,%0,%4;", ret, oldval, uaddr, oparg);
  56                 break;
  57         case FUTEX_OP_ANDN:
  58                 __futex_atomic_op("andn %1,%0,%4;", ret, oldval, uaddr, oparg);
  59                 break;
  60         case FUTEX_OP_XOR:
  61                 __futex_atomic_op("xor %1,%0,%4;", ret, oldval, uaddr, oparg);
  62                 break;
  63         default:
  64                 ret = -ENOSYS;
  65         }
  66
  67         pagefault_enable();
  68
  69         if (!ret) {
  70                 switch (cmp) {
  71                 case FUTEX_OP_CMP_EQ:
  72                         ret = (oldval == cmparg);
  73                         break;
  74                 case FUTEX_OP_CMP_NE:
  75                         ret = (oldval != cmparg);
  76                         break;
  77                 case FUTEX_OP_CMP_LT:
  78                         ret = (oldval < cmparg);
  79                         break;
  80                 case FUTEX_OP_CMP_GE:
  81                         ret = (oldval >= cmparg);
  82                         break;
  83                 case FUTEX_OP_CMP_LE:
  84                         ret = (oldval <= cmparg);
  85                         break;
  86                 case FUTEX_OP_CMP_GT:
  87                         ret = (oldval > cmparg);
  88                         break;
  89                 default:
  90                         ret = -ENOSYS;
  91                 }
  92         }
  93         return ret;
  94 }
  95
  96 static inline int
  97 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
  98                               u32 oldval, u32 newval)
  99 {
 100         int ret = 0, cmp;
 101         u32 prev;
 102
 103         if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
 104                 return -EFAULT;
 105
 106         __asm__ __volatile__ ("1:       lwx     %1, %3, r0;             \
 107                                         cmp     %2, %1, %4;             \
 108                                         bnei    %2, 3f;                 \
 109                                 2:      swx     %5, %3, r0;             \
 110                                         addic   %2, r0, 0;              \
 111                                         bnei    %2, 1b;                 \
 112                                 3:                                      \
 113                                 .section .fixup,\"ax\";                 \
 114                                 4:      brid    3b;                     \
 115                                         addik   %0, r0, %6;             \
 116                                 .previous;                              \
 117                                 .section __ex_table,\"a\";              \
 118                                 .word   1b,4b,2b,4b;                    \
 119                                 .previous;"                             \
 120                 : "+r" (ret), "=&r" (prev), "=&r"(cmp)  \
 121                 : "r" (uaddr), "r" (oldval), "r" (newval), "i" (-EFAULT));
 122
 123         *uval = prev;
 124         return ret;
 125 }
 126
 127 #endif /* __KERNEL__ */
 128
 129 #endif