arch/riscv/include/asm/syscall.h

   1 /*
   2  * Copyright (C) 2008-2009 Red Hat, Inc.  All rights reserved.
   3  * Copyright 2010 Tilera Corporation. All Rights Reserved.
   4  * Copyright 2015 Regents of the University of California, Berkeley
   5  *
   6  *   This program is free software; you can redistribute it and/or
   7  *   modify it under the terms of the GNU General Public License
   8  *   as published by the Free Software Foundation, version 2.
   9  *
  10  *   This program is distributed in the hope that it will be useful,
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *   GNU General Public License for more details.
  14  *
  15  * See asm-generic/syscall.h for descriptions of what we must do here.
  16  */
  17
  18 #ifndef _ASM_RISCV_SYSCALL_H
  19 #define _ASM_RISCV_SYSCALL_H
  20
  21 #include <uapi/linux/audit.h>
  22 #include <linux/sched.h>
  23 #include <linux/err.h>
  24
  25 /* The array of function pointers for syscalls. */
  26 extern void *sys_call_table[];
  27
  28 /*
  29  * Only the low 32 bits of orig_r0 are meaningful, so we return int.
  30  * This importantly ignores the high bits on 64-bit, so comparisons
  31  * sign-extend the low 32 bits.
  32  */
  33 static inline int syscall_get_nr(struct task_struct *task,
  34                                  struct pt_regs *regs)
  35 {
  36         return regs->a7;
  37 }
  38
  39 static inline void syscall_set_nr(struct task_struct *task,
  40                                   struct pt_regs *regs,
  41                                   int sysno)
  42 {
  43         regs->a7 = sysno;
  44 }
  45
  46 static inline void syscall_rollback(struct task_struct *task,
  47                                     struct pt_regs *regs)
  48 {
  49         regs->a0 = regs->orig_a0;
  50 }
  51
  52 static inline long syscall_get_error(struct task_struct *task,
  53                                      struct pt_regs *regs)
  54 {
  55         unsigned long error = regs->a0;
  56
  57         return IS_ERR_VALUE(error) ? error : 0;
  58 }
  59
  60 static inline long syscall_get_return_value(struct task_struct *task,
  61                                             struct pt_regs *regs)
  62 {
  63         return regs->a0;
  64 }
  65
  66 static inline void syscall_set_return_value(struct task_struct *task,
  67                                             struct pt_regs *regs,
  68                                             int error, long val)
  69 {
  70         regs->a0 = (long) error ?: val;
  71 }
  72
  73 static inline void syscall_get_arguments(struct task_struct *task,
  74                                          struct pt_regs *regs,
  75                                          unsigned int i, unsigned int n,
  76                                          unsigned long *args)
  77 {
  78         BUG_ON(i + n > 6);
  79         if (i == 0) {
  80                 args[0] = regs->orig_a0;
  81                 args++;
  82                 i++;
  83                 n--;
  84         }
  85         memcpy(args, &regs->a1 + i * sizeof(regs->a1), n * sizeof(args[0]));
  86 }
  87
  88 static inline void syscall_set_arguments(struct task_struct *task,
  89                                          struct pt_regs *regs,
  90                                          unsigned int i, unsigned int n,
  91                                          const unsigned long *args)
  92 {
  93         BUG_ON(i + n > 6);
  94         if (i == 0) {
  95                 regs->orig_a0 = args[0];
  96                 args++;
  97                 i++;
  98                 n--;
  99         }
 100         memcpy(&regs->a1 + i * sizeof(regs->a1), args, n * sizeof(regs->a0));
 101 }
 102
 103 static inline int syscall_get_arch(void)
 104 {
 105 #ifdef CONFIG_64BIT
 106         return AUDIT_ARCH_RISCV64;
 107 #else
 108         return AUDIT_ARCH_RISCV32;
 109 #endif
 110 }
 111
 112 #endif  /* _ASM_RISCV_SYSCALL_H */