arch/riscv/include/asm/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. */
  19 extern void * const sys_call_table[];
  20 extern void * const compat_sys_call_table[];
  21
  22 /*
  23  * Only the low 32 bits of orig_r0 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  */
  27 static inline int syscall_get_nr(struct task_struct *task,
  28                                  struct pt_regs *regs)
  29 {
  30         return regs->a7;
  31 }
  32
  33 static inline void syscall_rollback(struct task_struct *task,
  34                                     struct pt_regs *regs)
  35 {
  36         regs->a0 = regs->orig_a0;
  37 }
  38
  39 static inline long syscall_get_error(struct task_struct *task,
  40                                      struct pt_regs *regs)
  41 {
  42         unsigned long error = regs->a0;
  43
  44         return IS_ERR_VALUE(error) ? error : 0;
  45 }
  46
  47 static inline long syscall_get_return_value(struct task_struct *task,
  48                                             struct pt_regs *regs)
  49 {
  50         return regs->a0;
  51 }
  52
  53 static inline void syscall_set_return_value(struct task_struct *task,
  54                                             struct pt_regs *regs,
  55                                             int error, long val)
  56 {
  57         regs->a0 = (long) error ?: val;
  58 }
  59
  60 static inline void syscall_get_arguments(struct task_struct *task,
  61                                          struct pt_regs *regs,
  62                                          unsigned long *args)
  63 {
  64         args[0] = regs->orig_a0;
  65         args++;
  66         memcpy(args, &regs->a1, 5 * sizeof(args[0]));
  67 }
  68
  69 static inline int syscall_get_arch(struct task_struct *task)
  70 {
  71 #ifdef CONFIG_64BIT
  72         return AUDIT_ARCH_RISCV64;
  73 #else
  74         return AUDIT_ARCH_RISCV32;
  75 #endif
  76 }
  77
  78 typedef long (*syscall_t)(const struct pt_regs *);
  79 static inline void syscall_handler(struct pt_regs *regs, ulong syscall)
  80 {
  81         syscall_t fn;
  82
  83 #ifdef CONFIG_COMPAT
  84         if ((regs->status & SR_UXL) == SR_UXL_32)
  85                 fn = compat_sys_call_table[syscall];
  86         else
  87 #endif
  88                 fn = sys_call_table[syscall];
  89
  90         regs->a0 = fn(regs);
  91 }
  92
  93 static inline bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs)
  94 {
  95         return false;
  96 }
  97
  98 asmlinkage long sys_riscv_flush_icache(uintptr_t, uintptr_t, uintptr_t);
  99
 100 asmlinkage long sys_riscv_hwprobe(struct riscv_hwprobe *, size_t, size_t,
 101                                   unsigned long *, unsigned int);
 102 #endif  /* _ASM_RISCV_SYSCALL_H */