1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_POWERPC_FUTEX_H 3 #define _ASM_POWERPC_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/synch.h> 11 12 #define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \ 13 __asm__ __volatile ( \ 14 PPC_ATOMIC_ENTRY_BARRIER \ 15 "1: lwarx %0,0,%2\n" \ 16 insn \ 17 "2: stwcx. %1,0,%2\n" \ 18 "bne- 1b\n" \ 19 PPC_ATOMIC_EXIT_BARRIER \ 20 "li %1,0\n" \ 21 "3: .section .fixup,\"ax\"\n" \ 22 "4: li %1,%3\n" \ 23 "b 3b\n" \ 24 ".previous\n" \ 25 EX_TABLE(1b, 4b) \ 26 EX_TABLE(2b, 4b) \ 27 : "=&r" (oldval), "=&r" (ret) \ 28 : "b" (uaddr), "i" (-EFAULT), "r" (oparg) \ 29 : "cr0", "memory") 30 31 static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval, 32 u32 __user *uaddr) 33 { 34 int oldval = 0, ret; 35 36 uaddr = masked_user_access_begin(uaddr); 37 38 switch (op) { 39 case FUTEX_OP_SET: 40 __futex_atomic_op("mr %1,%4\n", ret, oldval, uaddr, oparg); 41 break; 42 case FUTEX_OP_ADD: 43 __futex_atomic_op("add %1,%0,%4\n", ret, oldval, uaddr, oparg); 44 break; 45 case FUTEX_OP_OR: 46 __futex_atomic_op("or %1,%0,%4\n", ret, oldval, uaddr, oparg); 47 break; 48 case FUTEX_OP_ANDN: 49 __futex_atomic_op("andc %1,%0,%4\n", ret, oldval, uaddr, oparg); 50 break; 51 case FUTEX_OP_XOR: 52 __futex_atomic_op("xor %1,%0,%4\n", ret, oldval, uaddr, oparg); 53 break; 54 default: 55 ret = -ENOSYS; 56 } 57 user_access_end(); 58 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; 69 u32 prev; 70 71 uaddr = masked_user_access_begin(uaddr); 72 73 __asm__ __volatile__ ( 74 PPC_ATOMIC_ENTRY_BARRIER 75 "1: lwarx %1,0,%3 # futex_atomic_cmpxchg_inatomic\n\ 76 cmpw 0,%1,%4\n\ 77 bne- 3f\n" 78 "2: stwcx. %5,0,%3\n\ 79 bne- 1b\n" 80 PPC_ATOMIC_EXIT_BARRIER 81 "3: .section .fixup,\"ax\"\n\ 82 4: li %0,%6\n\ 83 b 3b\n\ 84 .previous\n" 85 EX_TABLE(1b, 4b) 86 EX_TABLE(2b, 4b) 87 : "+r" (ret), "=&r" (prev), "+m" (*uaddr) 88 : "r" (uaddr), "r" (oldval), "r" (newval), "i" (-EFAULT) 89 : "cc", "memory"); 90 91 user_access_end(); 92 93 *uval = prev; 94 95 return ret; 96 } 97 98 #endif /* __KERNEL__ */ 99 #endif /* _ASM_POWERPC_FUTEX_H */ 100