arch/tile/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  *
   5  *   This program is free software; you can redistribute it and/or
   6  *   modify it under the terms of the GNU General Public License
   7  *   as published by the Free Software Foundation, version 2.
   8  *
   9  *   This program is distributed in the hope that it will be useful, but
  10  *   WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  12  *   NON INFRINGEMENT.  See the GNU General Public License for
  13  *   more details.
  14  *
  15  * See asm-generic/syscall.h for descriptions of what we must do here.
  16  */
  17
  18 #ifndef _ASM_TILE_SYSCALL_H
  19 #define _ASM_TILE_SYSCALL_H
  20
  21 #include <linux/sched.h>
  22 #include <linux/err.h>
  23 #include <linux/audit.h>
  24 #include <linux/compat.h>
  25 #include <arch/abi.h>
  26
  27 /* The array of function pointers for syscalls. */
  28 extern void *sys_call_table[];
  29 #ifdef CONFIG_COMPAT
  30 extern void *compat_sys_call_table[];
  31 #endif
  32
  33 /*
  34  * Only the low 32 bits of orig_r0 are meaningful, so we return int.
  35  * This importantly ignores the high bits on 64-bit, so comparisons
  36  * sign-extend the low 32 bits.
  37  */
  38 static inline int syscall_get_nr(struct task_struct *t, struct pt_regs *regs)
  39 {
  40         return regs->regs[TREG_SYSCALL_NR];
  41 }
  42
  43 static inline void syscall_rollback(struct task_struct *task,
  44                                     struct pt_regs *regs)
  45 {
  46         regs->regs[0] = regs->orig_r0;
  47 }
  48
  49 static inline long syscall_get_error(struct task_struct *task,
  50                                      struct pt_regs *regs)
  51 {
  52         unsigned long error = regs->regs[0];
  53         return IS_ERR_VALUE(error) ? error : 0;
  54 }
  55
  56 static inline long syscall_get_return_value(struct task_struct *task,
  57                                             struct pt_regs *regs)
  58 {
  59         return regs->regs[0];
  60 }
  61
  62 static inline void syscall_set_return_value(struct task_struct *task,
  63                                             struct pt_regs *regs,
  64                                             int error, long val)
  65 {
  66         if (error) {
  67                 /* R0 is the passed-in negative error, R1 is positive. */
  68                 regs->regs[0] = error;
  69                 regs->regs[1] = -error;
  70         } else {
  71                 /* R1 set to zero to indicate no error. */
  72                 regs->regs[0] = val;
  73                 regs->regs[1] = 0;
  74         }
  75 }
  76
  77 static inline void syscall_get_arguments(struct task_struct *task,
  78                                          struct pt_regs *regs,
  79                                          unsigned int i, unsigned int n,
  80                                          unsigned long *args)
  81 {
  82         BUG_ON(i + n > 6);
  83         memcpy(args, &regs[i], n * sizeof(args[0]));
  84 }
  85
  86 static inline void syscall_set_arguments(struct task_struct *task,
  87                                          struct pt_regs *regs,
  88                                          unsigned int i, unsigned int n,
  89                                          const unsigned long *args)
  90 {
  91         BUG_ON(i + n > 6);
  92         memcpy(&regs[i], args, n * sizeof(args[0]));
  93 }
  94
  95 /*
  96  * We don't care about endianness (__AUDIT_ARCH_LE bit) here because
  97  * tile has the same system calls both on little- and big- endian.
  98  */
  99 static inline int syscall_get_arch(void)
 100 {
 101         if (is_compat_task())
 102                 return AUDIT_ARCH_TILEGX32;
 103
 104 #ifdef CONFIG_TILEGX
 105         return AUDIT_ARCH_TILEGX;
 106 #else
 107         return AUDIT_ARCH_TILEPRO;
 108 #endif
 109 }
 110
 111 #endif  /* _ASM_TILE_SYSCALL_H */