Logo Search packages:      
Sourcecode: linux version File versions  Download package

syscall.h

/*
 * Magic syscall break down functions
 *
 * Copyright 2010 Analog Devices Inc.
 *
 * Licensed under the GPL-2 or later.
 */

#ifndef __ASM_BLACKFIN_SYSCALL_H__
#define __ASM_BLACKFIN_SYSCALL_H__

/*
 * Blackfin syscalls are simple:
 *    enter:
 *          p0: syscall number
 *          r{0,1,2,3,4,5}: syscall args 0,1,2,3,4,5
 *    exit:
 *          r0: return/error value
 */

#include <linux/err.h>
#include <linux/sched.h>
#include <asm/ptrace.h>

static inline long
syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
{
      return regs->p0;
}

static inline void
syscall_rollback(struct task_struct *task, struct pt_regs *regs)
{
      regs->p0 = regs->orig_p0;
}

static inline long
syscall_get_error(struct task_struct *task, struct pt_regs *regs)
{
      return IS_ERR_VALUE(regs->r0) ? regs->r0 : 0;
}

static inline long
syscall_get_return_value(struct task_struct *task, struct pt_regs *regs)
{
      return regs->r0;
}

static inline void
syscall_set_return_value(struct task_struct *task, struct pt_regs *regs,
                         int error, long val)
{
      regs->r0 = error ? -error : val;
}

/**
 *    syscall_get_arguments()
 *    @task:   unused
 *    @regs:   the register layout to extract syscall arguments from
 *    @i:      first syscall argument to extract
 *    @n:      number of syscall arguments to extract
 *    @args:   array to return the syscall arguments in
 *
 * args[0] gets i'th argument, args[n - 1] gets the i+n-1'th argument
 */
static inline void
syscall_get_arguments(struct task_struct *task, struct pt_regs *regs,
                      unsigned int i, unsigned int n, unsigned long *args)
{
      /*
       * Assume the ptrace layout doesn't change -- r5 is first in memory,
       * then r4, ..., then r0.  So we simply reverse the ptrace register
       * array in memory to store into the args array.
       */
      long *aregs = &regs->r0 - i;

      BUG_ON(i > 5 || i + n > 6);

      while (n--)
            *args++ = *aregs--;
}

/* See syscall_get_arguments() comments */
static inline void
syscall_set_arguments(struct task_struct *task, struct pt_regs *regs,
                      unsigned int i, unsigned int n, const unsigned long *args)
{
      long *aregs = &regs->r0 - i;

      BUG_ON(i > 5 || i + n > 6);

      while (n--)
            *aregs-- = *args++;
}

#endif

Generated by  Doxygen 1.6.0   Back to index