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 #include <asm/asm-compat.h> 12 13 #define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \ 14 __asm__ __volatile ( \ 15 PPC_ATOMIC_ENTRY_BARRIER \ 16 "1: lwarx %0,0,%2\n" \ 17 insn \ 18 PPC405_ERR77(0, %2) \ 19 "2: stwcx. %1,0,%2\n" \ 20 "bne- 1b\n" \ 21 PPC_ATOMIC_EXIT_BARRIER \ 22 "li %1,0\n" \ 23 "3: .section .fixup,\"ax\"\n" \ 24 "4: li %1,%3\n" \ 25 "b 3b\n" \ 26 ".previous\n" \ 27 EX_TABLE(1b, 4b) \ 28 EX_TABLE(2b, 4b) \ 29 : "=&r" (oldval), "=&r" (ret) \ 30 : "b" (uaddr), "i" (-EFAULT), "r" (oparg) \ 31 : "cr0", "memory") 32 33 static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval, 34 u32 __user *uaddr) 35 { 36 int oldval = 0, ret; 37 38 pagefault_disable(); 39 40 switch (op) { 41 case FUTEX_OP_SET: 42 __futex_atomic_op("mr %1,%4\n", ret, oldval, uaddr, oparg); 43 break; 44 case FUTEX_OP_ADD: 45 __futex_atomic_op("add %1,%0,%4\n", ret, oldval, uaddr, oparg); 46 break; 47 case FUTEX_OP_OR: 48 __futex_atomic_op("or %1,%0,%4\n", ret, oldval, uaddr, oparg); 49 break; 50 case FUTEX_OP_ANDN: 51 __futex_atomic_op("andc %1,%0,%4\n", ret, oldval, uaddr, oparg); 52 break; 53 case FUTEX_OP_XOR: 54 __futex_atomic_op("xor %1,%0,%4\n", ret, oldval, uaddr, oparg); 55 break; 56 default: 57 ret = -ENOSYS; 58 } 59 60 pagefault_enable(); 61 62 if (!ret) 63 *oval = oldval; 64 65 return ret; 66 } 67 68 static inline int 69 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, 70 u32 oldval, u32 newval) 71 { 72 int ret = 0; 73 u32 prev; 74 75 if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) 76 return -EFAULT; 77 78 __asm__ __volatile__ ( 79 PPC_ATOMIC_ENTRY_BARRIER 80 "1: lwarx %1,0,%3 # futex_atomic_cmpxchg_inatomic\n\ 81 cmpw 0,%1,%4\n\ 82 bne- 3f\n" 83 PPC405_ERR77(0,%3) 84 "2: stwcx. %5,0,%3\n\ 85 bne- 1b\n" 86 PPC_ATOMIC_EXIT_BARRIER 87 "3: .section .fixup,\"ax\"\n\ 88 4: li %0,%6\n\ 89 b 3b\n\ 90 .previous\n" 91 EX_TABLE(1b, 4b) 92 EX_TABLE(2b, 4b) 93 : "+r" (ret), "=&r" (prev), "+m" (*uaddr) 94 : "r" (uaddr), "r" (oldval), "r" (newval), "i" (-EFAULT) 95 : "cc", "memory"); 96 97 *uval = prev; 98 return ret; 99 } 100 101 #endif /* __KERNEL__ */ 102 #endif /* _ASM_POWERPC_FUTEX_H */ 103