| /* SPDX-License-Identifier: GPL-2.0 */ |
| /* |
| * Copyright (c) 2006 Ralf Baechle (ralf@linux-mips.org) |
| * Copyright (c) 2018 Jim Wilson (jimw@sifive.com) |
| */ |
| |
| #ifndef _ASM_FUTEX_H |
| #define _ASM_FUTEX_H |
| |
| #include <linux/futex.h> |
| #include <linux/uaccess.h> |
| #include <linux/errno.h> |
| #include <asm/asm.h> |
| |
| #define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \ |
| { \ |
| uintptr_t tmp; \ |
| __enable_user_access(); \ |
| __asm__ __volatile__ ( \ |
| "1: " insn " \n" \ |
| "2: \n" \ |
| " .section .fixup,\"ax\" \n" \ |
| " .balign 4 \n" \ |
| "3: li %[r],%[e] \n" \ |
| " jump 2b,%[t] \n" \ |
| " .previous \n" \ |
| " .section __ex_table,\"a\" \n" \ |
| " .balign " RISCV_SZPTR " \n" \ |
| " " RISCV_PTR " 1b, 3b \n" \ |
| " .previous \n" \ |
| : [r] "+r" (ret), [ov] "=&r" (oldval), \ |
| [u] "+m" (*uaddr), [t] "=&r" (tmp) \ |
| : [op] "Jr" (oparg), [e] "i" (-EFAULT) \ |
| : "memory"); \ |
| __disable_user_access(); \ |
| } |
| |
| static inline int |
| arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr) |
| { |
| int oldval = 0, ret = 0; |
| |
| pagefault_disable(); |
| |
| switch (op) { |
| case FUTEX_OP_SET: |
| __futex_atomic_op("amoswap.w.aqrl %[ov],%z[op],%[u]", |
| ret, oldval, uaddr, oparg); |
| break; |
| case FUTEX_OP_ADD: |
| __futex_atomic_op("amoadd.w.aqrl %[ov],%z[op],%[u]", |
| ret, oldval, uaddr, oparg); |
| break; |
| case FUTEX_OP_OR: |
| __futex_atomic_op("amoor.w.aqrl %[ov],%z[op],%[u]", |
| ret, oldval, uaddr, oparg); |
| break; |
| case FUTEX_OP_ANDN: |
| __futex_atomic_op("amoand.w.aqrl %[ov],%z[op],%[u]", |
| ret, oldval, uaddr, ~oparg); |
| break; |
| case FUTEX_OP_XOR: |
| __futex_atomic_op("amoxor.w.aqrl %[ov],%z[op],%[u]", |
| ret, oldval, uaddr, oparg); |
| break; |
| default: |
| ret = -ENOSYS; |
| } |
| |
| pagefault_enable(); |
| |
| if (!ret) |
| *oval = oldval; |
| |
| return ret; |
| } |
| |
| static inline int |
| futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, |
| u32 oldval, u32 newval) |
| { |
| int ret = 0; |
| u32 val; |
| uintptr_t tmp; |
| |
| if (!access_ok(uaddr, sizeof(u32))) |
| return -EFAULT; |
| |
| __enable_user_access(); |
| __asm__ __volatile__ ( |
| "1: lr.w.aqrl %[v],%[u] \n" |
| " bne %[v],%z[ov],3f \n" |
| "2: sc.w.aqrl %[t],%z[nv],%[u] \n" |
| " bnez %[t],1b \n" |
| "3: \n" |
| " .section .fixup,\"ax\" \n" |
| " .balign 4 \n" |
| "4: li %[r],%[e] \n" |
| " jump 3b,%[t] \n" |
| " .previous \n" |
| " .section __ex_table,\"a\" \n" |
| " .balign " RISCV_SZPTR " \n" |
| " " RISCV_PTR " 1b, 4b \n" |
| " " RISCV_PTR " 2b, 4b \n" |
| " .previous \n" |
| : [r] "+r" (ret), [v] "=&r" (val), [u] "+m" (*uaddr), [t] "=&r" (tmp) |
| : [ov] "Jr" (oldval), [nv] "Jr" (newval), [e] "i" (-EFAULT) |
| : "memory"); |
| __disable_user_access(); |
| |
| *uval = val; |
| return ret; |
| } |
| |
| #endif /* _ASM_FUTEX_H */ |