1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_ALPHA_FUTEX_H 3 #define _ASM_ALPHA_FUTEX_H 4 5 #ifdef __KERNEL__ 6 7 #include <linux/futex.h> 8 #include <linux/uaccess.h> 9 #include <asm/errno.h> 10 #include <asm/barrier.h> 11 12 #define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \ 13 __asm__ __volatile__( \ 14 __ASM_SMP_MB \ 15 "1: ldl_l %0,0(%2)\n" \ 16 insn \ 17 "2: stl_c %1,0(%2)\n" \ 18 " beq %1,4f\n" \ 19 " mov $31,%1\n" \ 20 "3: .subsection 2\n" \ 21 "4: br 1b\n" \ 22 " .previous\n" \ 23 EXC(1b,3b,%1,$31) \ 24 EXC(2b,3b,%1,$31) \ 25 : "=&r" (oldval), "=&r"(ret) \ 26 : "r" (uaddr), "r"(oparg) \ 27 : "memory") 28 29 static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval, 30 u32 __user *uaddr) 31 { 32 int oldval = 0, ret; 33 34 pagefault_disable(); 35 36 switch (op) { 37 case FUTEX_OP_SET: 38 __futex_atomic_op("mov %3,%1\n", ret, oldval, uaddr, oparg); 39 break; 40 case FUTEX_OP_ADD: 41 __futex_atomic_op("addl %0,%3,%1\n", ret, oldval, uaddr, oparg); 42 break; 43 case FUTEX_OP_OR: 44 __futex_atomic_op("or %0,%3,%1\n", ret, oldval, uaddr, oparg); 45 break; 46 case FUTEX_OP_ANDN: 47 __futex_atomic_op("andnot %0,%3,%1\n", ret, oldval, uaddr, oparg); 48 break; 49 case FUTEX_OP_XOR: 50 __futex_atomic_op("xor %0,%3,%1\n", ret, oldval, uaddr, oparg); 51 break; 52 default: 53 ret = -ENOSYS; 54 } 55 56 pagefault_enable(); 57 58 if (!ret) 59 *oval = oldval; 60 61 return ret; 62 } 63 64 static inline int 65 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, 66 u32 oldval, u32 newval) 67 { 68 int ret = 0, cmp; 69 u32 prev; 70 71 if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) 72 return -EFAULT; 73 74 __asm__ __volatile__ ( 75 __ASM_SMP_MB 76 "1: ldl_l %1,0(%3)\n" 77 " cmpeq %1,%4,%2\n" 78 " beq %2,3f\n" 79 " mov %5,%2\n" 80 "2: stl_c %2,0(%3)\n" 81 " beq %2,4f\n" 82 "3: .subsection 2\n" 83 "4: br 1b\n" 84 " .previous\n" 85 EXC(1b,3b,%0,$31) 86 EXC(2b,3b,%0,$31) 87 : "+r"(ret), "=&r"(prev), "=&r"(cmp) 88 : "r"(uaddr), "r"((long)(int)oldval), "r"(newval) 89 : "memory"); 90 91 *uval = prev; 92 return ret; 93 } 94 95 #endif /* __KERNEL__ */ 96 #endif /* _ASM_ALPHA_FUTEX_H */ 97