arch/nios2/include/asm/syscall.h

   1 /*
   2  * Copyright Altera Corporation (C) <2014>. All rights reserved
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program.  If not, see <http://www.gnu.org/licenses/>.
  15  */
  16
  17 #ifndef __ASM_NIOS2_SYSCALL_H__
  18 #define __ASM_NIOS2_SYSCALL_H__
  19
  20 #include <linux/err.h>
  21 #include <linux/sched.h>
  22
  23 static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
  24 {
  25         return regs->r2;
  26 }
  27
  28 static inline void syscall_rollback(struct task_struct *task,
  29                                 struct pt_regs *regs)
  30 {
  31         regs->r2 = regs->orig_r2;
  32         regs->r7 = regs->orig_r7;
  33 }
  34
  35 static inline long syscall_get_error(struct task_struct *task,
  36                                 struct pt_regs *regs)
  37 {
  38         return regs->r7 ? regs->r2 : 0;
  39 }
  40
  41 static inline long syscall_get_return_value(struct task_struct *task,
  42         struct pt_regs *regs)
  43 {
  44         return regs->r2;
  45 }
  46
  47 static inline void syscall_set_return_value(struct task_struct *task,
  48         struct pt_regs *regs, int error, long val)
  49 {
  50         if (error) {
  51                 /* error < 0, but nios2 uses > 0 return value */
  52                 regs->r2 = -error;
  53                 regs->r7 = 1;
  54         } else {
  55                 regs->r2 = val;
  56                 regs->r7 = 0;
  57         }
  58 }
  59
  60 static inline void syscall_get_arguments(struct task_struct *task,
  61         struct pt_regs *regs, unsigned int i, unsigned int n,
  62         unsigned long *args)
  63 {
  64         BUG_ON(i + n > 6);
  65
  66         switch (i) {
  67         case 0:
  68                 if (!n--)
  69                         break;
  70                 *args++ = regs->r4;
  71         case 1:
  72                 if (!n--)
  73                         break;
  74                 *args++ = regs->r5;
  75         case 2:
  76                 if (!n--)
  77                         break;
  78                 *args++ = regs->r6;
  79         case 3:
  80                 if (!n--)
  81                         break;
  82                 *args++ = regs->r7;
  83         case 4:
  84                 if (!n--)
  85                         break;
  86                 *args++ = regs->r8;
  87         case 5:
  88                 if (!n--)
  89                         break;
  90                 *args++ = regs->r9;
  91         case 6:
  92                 if (!n--)
  93                         break;
  94         default:
  95                 BUG();
  96         }
  97 }
  98
  99 static inline void syscall_set_arguments(struct task_struct *task,
 100         struct pt_regs *regs, unsigned int i, unsigned int n,
 101         const unsigned long *args)
 102 {
 103         BUG_ON(i + n > 6);
 104
 105         switch (i) {
 106         case 0:
 107                 if (!n--)
 108                         break;
 109                 regs->r4 = *args++;
 110         case 1:
 111                 if (!n--)
 112                         break;
 113                 regs->r5 = *args++;
 114         case 2:
 115                 if (!n--)
 116                         break;
 117                 regs->r6 = *args++;
 118         case 3:
 119                 if (!n--)
 120                         break;
 121                 regs->r7 = *args++;
 122         case 4:
 123                 if (!n--)
 124                         break;
 125                 regs->r8 = *args++;
 126         case 5:
 127                 if (!n--)
 128                         break;
 129                 regs->r9 = *args++;
 130         case 6:
 131                 if (!n)
 132                         break;
 133         default:
 134                 BUG();
 135         }
 136 }
 137
 138 #endif