LXR linux/arch/sh/include/asm/syscall

   1#ifndef __ASM_SH_SYSCALL_32_H
   2#define __ASM_SH_SYSCALL_32_H
   3
   4#include <linux/kernel.h>
   5#include <linux/sched.h>
   6#include <linux/err.h>
   7#include <asm/ptrace.h>
   8
   9/* The system call number is given by the user in R3 */
  10static inline long syscall_get_nr(struct task_struct *task,
  11                                  struct pt_regs *regs)
  12{
  13        return (regs->tra >= 0) ? regs->regs[3] : -1L;
  14}
  15
  16static inline void syscall_rollback(struct task_struct *task,
  17                                    struct pt_regs *regs)
  18{
  19        /*
  20         * XXX: This needs some thought. On SH we don't
  21         * save away the original r0 value anywhere.
  22         */
  23}
  24
  25static inline long syscall_get_error(struct task_struct *task,
  26                                     struct pt_regs *regs)
  27{
  28        return IS_ERR_VALUE(regs->regs[0]) ? regs->regs[0] : 0;
  29}
  30
  31static inline long syscall_get_return_value(struct task_struct *task,
  32                                            struct pt_regs *regs)
  33{
  34        return regs->regs[0];
  35}
  36
  37static inline void syscall_set_return_value(struct task_struct *task,
  38                                            struct pt_regs *regs,
  39                                            int error, long val)
  40{
  41        if (error)
  42                regs->regs[0] = -error;
  43        else
  44                regs->regs[0] = val;
  45}
  46
  47static inline void syscall_get_arguments(struct task_struct *task,
  48                                         struct pt_regs *regs,
  49                                         unsigned int i, unsigned int n,
  50                                         unsigned long *args)
  51{
  52        /*
  53         * Do this simply for now. If we need to start supporting
  54         * fetching arguments from arbitrary indices, this will need some
  55         * extra logic. Presently there are no in-tree users that depend
  56         * on this behaviour.
  57         */
  58        BUG_ON(i);
  59
  60        /* Argument pattern is: R4, R5, R6, R7, R0, R1 */
  61        switch (n) {
  62        case 6: args[5] = regs->regs[1];
  63        case 5: args[4] = regs->regs[0];
  64        case 4: args[3] = regs->regs[7];
  65        case 3: args[2] = regs->regs[6];
  66        case 2: args[1] = regs->regs[5];
  67        case 1: args[0] = regs->regs[4];
  68        case 0:
  69                break;
  70        default:
  71                BUG();
  72        }
  73}
  74
  75static inline void syscall_set_arguments(struct task_struct *task,
  76                                         struct pt_regs *regs,
  77                                         unsigned int i, unsigned int n,
  78                                         const unsigned long *args)
  79{
  80        /* Same note as above applies */
  81        BUG_ON(i);
  82
  83        switch (n) {
  84        case 6: regs->regs[1] = args[5];
  85        case 5: regs->regs[0] = args[4];
  86        case 4: regs->regs[7] = args[3];
  87        case 3: regs->regs[6] = args[2];
  88        case 2: regs->regs[5] = args[1];
  89        case 1: regs->regs[4] = args[0];
  90                break;
  91        default:
  92                BUG();
  93        }
  94}
  95
  96#endif /* __ASM_SH_SYSCALL_32_H */
  97