linux/arch/powerpc/include/asm/syscall.h

/*
 * Access to user system call parameters and results
 *
 * Copyright (C) 2008 Red Hat, Inc.  All rights reserved.
 *
 * This copyrighted material is made available to anyone wishing to use,
 * modify, copy, or redistribute it subject to the terms and conditions
 * of the GNU General Public License v.2.
 *
 * See asm-generic/syscall.h for descriptions of what we must do here.
 */

#ifndef _ASM_SYSCALL_H
#define _ASM_SYSCALL_H	1

#include <uapi/linux/audit.h>
#include <linux/sched.h>
#include <linux/thread_info.h>

/* ftrace syscalls requires exporting the sys_call_table */
#ifdef CONFIG_FTRACE_SYSCALLS
extern const unsigned long sys_call_table[];
#endif /* CONFIG_FTRACE_SYSCALLS */

static inline long syscall_get_nr(struct task_struct *task,
				  struct pt_regs *regs)
{
	return TRAP(regs) == 0xc00 ? regs->gpr[0] : -1L;
}

static inline void syscall_rollback(struct task_struct *task,
				    struct pt_regs *regs)
{
	regs->gpr[3] = regs->orig_gpr3;
}

static inline long syscall_get_return_value(struct task_struct *task,
					    struct pt_regs *regs)
{
	return regs->gpr[3];
}

static inline void syscall_set_return_value(struct task_struct *task,
					    struct pt_regs *regs,
					    int error, long val)
{
	/*
	 * In the general case it's not obvious that we must deal with CCR
	 * here, as the syscall exit path will also do that for us. However
	 * there are some places, eg. the signal code, which check ccr to
	 * decide if the value in r3 is actually an error.
	 */
	if (error) {
		regs->ccr |= 0x10000000L;
		regs->gpr[3] = error;
	} else {
		regs->ccr &= ~0x10000000L;
		regs->gpr[3] = val;
	}
}

static inline void syscall_get_arguments(struct task_struct *task,
					 struct pt_regs *regs,
					 unsigned int i, unsigned int n,
					 unsigned long *args)
{
	BUG_ON(i + n > 6);
#ifdef CONFIG_PPC64
	if (test_tsk_thread_flag(task, TIF_32BIT)) {
		/*
		 * Zero-extend 32-bit argument values.  The high bits are
		 * garbage ignored by the actual syscall dispatch.
		 */
		while (n-- > 0)
			args[n] = (u32) regs->gpr[3 + i + n];
		return;
	}
#endif
	memcpy(args, &regs->gpr[3 + i], n * sizeof(args[0]));
}

static inline void syscall_set_arguments(struct task_struct *task,
					 struct pt_regs *regs,
					 unsigned int i, unsigned int n,
					 const unsigned long *args)
{
	BUG_ON(i + n > 6);
	memcpy(&regs->gpr[3 + i], args, n * sizeof(args[0]));
}

static inline int syscall_get_arch(void)
{
	int arch = is_32bit_task() ? AUDIT_ARCH_PPC : AUDIT_ARCH_PPC64;
#ifdef __LITTLE_ENDIAN__
	arch |= __AUDIT_ARCH_LE;
#endif
	return arch;
}
#endif	/* _ASM_SYSCALL_H */