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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 | /* SPDX-License-Identifier: GPL-2.0 */ #ifndef _ASM_FUTEX_H #define _ASM_FUTEX_H #include <linux/futex.h> #include <linux/uaccess.h> #include <asm/errno.h> #define __futex_atomic_op1(insn, ret, oldval, uaddr, oparg) \ do { \ register unsigned long r8 __asm ("r8") = 0; \ __asm__ __volatile__( \ " mf;; \n" \ "[1:] " insn ";; \n" \ " .xdata4 \"__ex_table\", 1b-., 2f-. \n" \ "[2:]" \ : "+r" (r8), "=r" (oldval) \ : "r" (uaddr), "r" (oparg) \ : "memory"); \ ret = r8; \ } while (0) #define __futex_atomic_op2(insn, ret, oldval, uaddr, oparg) \ do { \ register unsigned long r8 __asm ("r8") = 0; \ int val, newval; \ do { \ __asm__ __volatile__( \ " mf;; \n" \ "[1:] ld4 %3=[%4];; \n" \ " mov %2=%3 \n" \ insn ";; \n" \ " mov ar.ccv=%2;; \n" \ "[2:] cmpxchg4.acq %1=[%4],%3,ar.ccv;; \n" \ " .xdata4 \"__ex_table\", 1b-., 3f-.\n" \ " .xdata4 \"__ex_table\", 2b-., 3f-.\n" \ "[3:]" \ : "+r" (r8), "=r" (val), "=&r" (oldval), \ "=&r" (newval) \ : "r" (uaddr), "r" (oparg) \ : "memory"); \ if (unlikely (r8)) \ break; \ } while (unlikely (val != oldval)); \ ret = r8; \ } while (0) static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr) { int oldval = 0, ret; if (!access_ok(uaddr, sizeof(u32))) return -EFAULT; switch (op) { case FUTEX_OP_SET: __futex_atomic_op1("xchg4 %1=[%2],%3", ret, oldval, uaddr, oparg); break; case FUTEX_OP_ADD: __futex_atomic_op2("add %3=%3,%5", ret, oldval, uaddr, oparg); break; case FUTEX_OP_OR: __futex_atomic_op2("or %3=%3,%5", ret, oldval, uaddr, oparg); break; case FUTEX_OP_ANDN: __futex_atomic_op2("and %3=%3,%5", ret, oldval, uaddr, ~oparg); break; case FUTEX_OP_XOR: __futex_atomic_op2("xor %3=%3,%5", ret, oldval, uaddr, oparg); break; default: ret = -ENOSYS; } if (!ret) *oval = oldval; return ret; } static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, u32 oldval, u32 newval) { if (!access_ok(uaddr, sizeof(u32))) return -EFAULT; { register unsigned long r8 __asm ("r8") = 0; unsigned long prev; __asm__ __volatile__( " mf;; \n" " mov ar.ccv=%4;; \n" "[1:] cmpxchg4.acq %1=[%2],%3,ar.ccv \n" " .xdata4 \"__ex_table\", 1b-., 2f-. \n" "[2:]" : "+r" (r8), "=&r" (prev) : "r" (uaddr), "r" (newval), "rO" ((long) (unsigned) oldval) : "memory"); *uval = prev; return r8; } } #endif /* _ASM_FUTEX_H */ |