syscall.h

  1/* SPDX-License-Identifier: GPL-2.0-only */
  2/*
  3 * Copyright (C) 2008-2009 Red Hat, Inc.  All rights reserved.
  4 * Copyright 2010 Tilera Corporation. All Rights Reserved.
  5 * Copyright 2015 Regents of the University of California, Berkeley
  6 *
  7 * See asm-generic/syscall.h for descriptions of what we must do here.
  8 */
  9
 10#ifndef _ASM_RISCV_SYSCALL_H
 11#define _ASM_RISCV_SYSCALL_H
 12
 13#include <asm/hwprobe.h>
 14#include <uapi/linux/audit.h>
 15#include <linux/sched.h>
 16#include <linux/err.h>
 17
 18/* The array of function pointers for syscalls. */
 19extern void * const sys_call_table[];
 20extern void * const compat_sys_call_table[];
 21
 22/*
 23 * Only the low 32 bits of orig_a0 are meaningful, so we return int.
 24 * This importantly ignores the high bits on 64-bit, so comparisons
 25 * sign-extend the low 32 bits.
 26 */
 27static inline int syscall_get_nr(struct task_struct *task,
 28				 struct pt_regs *regs)
 29{
 30	return regs->a7;
 31}
 32
 33static inline void syscall_set_nr(struct task_struct *task,
 34				  struct pt_regs *regs,
 35				  int nr)
 36{
 37	regs->a7 = nr;
 38}
 39
 40static inline void syscall_rollback(struct task_struct *task,
 41				    struct pt_regs *regs)
 42{
 43        regs->a0 = regs->orig_a0;
 44}
 45
 46static inline long syscall_get_error(struct task_struct *task,
 47				     struct pt_regs *regs)
 48{
 49	unsigned long error = regs->a0;
 50
 51	return IS_ERR_VALUE(error) ? error : 0;
 52}
 53
 54static inline long syscall_get_return_value(struct task_struct *task,
 55					    struct pt_regs *regs)
 56{
 57	return regs->a0;
 58}
 59
 60static inline void syscall_set_return_value(struct task_struct *task,
 61					    struct pt_regs *regs,
 62					    int error, long val)
 63{
 64	regs->a0 = (long) error ?: val;
 65}
 66
 67static inline void syscall_get_arguments(struct task_struct *task,
 68					 struct pt_regs *regs,
 69					 unsigned long *args)
 70{
 71	args[0] = regs->orig_a0;
 72	args[1] = regs->a1;
 73	args[2] = regs->a2;
 74	args[3] = regs->a3;
 75	args[4] = regs->a4;
 76	args[5] = regs->a5;
 77}
 78
 79static inline void syscall_set_arguments(struct task_struct *task,
 80					 struct pt_regs *regs,
 81					 const unsigned long *args)
 82{
 83	regs->orig_a0 = args[0];
 84	regs->a1 = args[1];
 85	regs->a2 = args[2];
 86	regs->a3 = args[3];
 87	regs->a4 = args[4];
 88	regs->a5 = args[5];
 89}
 90
 91static inline int syscall_get_arch(struct task_struct *task)
 92{
 93#ifdef CONFIG_64BIT
 94	return AUDIT_ARCH_RISCV64;
 95#else
 96	return AUDIT_ARCH_RISCV32;
 97#endif
 98}
 99
100typedef long (*syscall_t)(const struct pt_regs *);
101static inline void syscall_handler(struct pt_regs *regs, ulong syscall)
102{
103	syscall_t fn;
104
105#ifdef CONFIG_COMPAT
106	if ((regs->status & SR_UXL) == SR_UXL_32)
107		fn = compat_sys_call_table[syscall];
108	else
109#endif
110		fn = sys_call_table[syscall];
111
112	regs->a0 = fn(regs);
113}
114
115static inline bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs)
116{
117	return false;
118}
119
120asmlinkage long sys_riscv_flush_icache(uintptr_t, uintptr_t, uintptr_t);
121
122asmlinkage long sys_riscv_hwprobe(struct riscv_hwprobe *, size_t, size_t,
123				  unsigned long *, unsigned int);
124#endif	/* _ASM_RISCV_SYSCALL_H */