futex.h 2.0 KB

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  1. /* SPDX-License-Identifier: GPL-2.0 */
  2. #ifndef _ASM_ALPHA_FUTEX_H
  3. #define _ASM_ALPHA_FUTEX_H
  4. #ifdef __KERNEL__
  5. #include <linux/futex.h>
  6. #include <linux/uaccess.h>
  7. #include <asm/errno.h>
  8. #include <asm/barrier.h>
  9. #define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
  10. __asm__ __volatile__( \
  11. __ASM_SMP_MB \
  12. "1: ldl_l %0,0(%2)\n" \
  13. insn \
  14. "2: stl_c %1,0(%2)\n" \
  15. " beq %1,4f\n" \
  16. " mov $31,%1\n" \
  17. "3: .subsection 2\n" \
  18. "4: br 1b\n" \
  19. " .previous\n" \
  20. EXC(1b,3b,$31,%1) \
  21. EXC(2b,3b,$31,%1) \
  22. : "=&r" (oldval), "=&r"(ret) \
  23. : "r" (uaddr), "r"(oparg) \
  24. : "memory")
  25. static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
  26. u32 __user *uaddr)
  27. {
  28. int oldval = 0, ret;
  29. if (!access_ok(uaddr, sizeof(u32)))
  30. return -EFAULT;
  31. switch (op) {
  32. case FUTEX_OP_SET:
  33. __futex_atomic_op("mov %3,%1\n", ret, oldval, uaddr, oparg);
  34. break;
  35. case FUTEX_OP_ADD:
  36. __futex_atomic_op("addl %0,%3,%1\n", ret, oldval, uaddr, oparg);
  37. break;
  38. case FUTEX_OP_OR:
  39. __futex_atomic_op("or %0,%3,%1\n", ret, oldval, uaddr, oparg);
  40. break;
  41. case FUTEX_OP_ANDN:
  42. __futex_atomic_op("andnot %0,%3,%1\n", ret, oldval, uaddr, oparg);
  43. break;
  44. case FUTEX_OP_XOR:
  45. __futex_atomic_op("xor %0,%3,%1\n", ret, oldval, uaddr, oparg);
  46. break;
  47. default:
  48. ret = -ENOSYS;
  49. }
  50. if (!ret)
  51. *oval = oldval;
  52. return ret;
  53. }
  54. static inline int
  55. futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
  56. u32 oldval, u32 newval)
  57. {
  58. int ret = 0, cmp;
  59. u32 prev;
  60. if (!access_ok(uaddr, sizeof(u32)))
  61. return -EFAULT;
  62. __asm__ __volatile__ (
  63. __ASM_SMP_MB
  64. "1: ldl_l %1,0(%3)\n"
  65. " cmpeq %1,%4,%2\n"
  66. " beq %2,3f\n"
  67. " mov %5,%2\n"
  68. "2: stl_c %2,0(%3)\n"
  69. " beq %2,4f\n"
  70. "3: .subsection 2\n"
  71. "4: br 1b\n"
  72. " .previous\n"
  73. EXC(1b,3b,$31,%0)
  74. EXC(2b,3b,$31,%0)
  75. : "+r"(ret), "=&r"(prev), "=&r"(cmp)
  76. : "r"(uaddr), "r"((long)(int)oldval), "r"(newval)
  77. : "memory");
  78. *uval = prev;
  79. return ret;
  80. }
  81. #endif /* __KERNEL__ */
  82. #endif /* _ASM_ALPHA_FUTEX_H */