/*

 * 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_X86_SYSCALL_H

#define _ASM_X86_SYSCALL_H

#include <linux/sched.h>

#include <linux/err.h>

static inline long syscall_get_nr(struct task_struct *task,

				  struct pt_regs *regs)

{

	/*

	 * We always sign-extend a -1 value being set here,

	 * so this is always either -1L or a syscall number.

	 */

	return regs->orig_ax;

}

static inline void syscall_rollback(struct task_struct *task,

				    struct pt_regs *regs)

{

	regs->ax = regs->orig_ax;

}

static inline long syscall_get_error(struct task_struct *task,

				     struct pt_regs *regs)

{

	unsigned long error = regs->ax;

#ifdef CONFIG_IA32_EMULATION

	/*

	 * TS_COMPAT is set for 32-bit syscall entries and then

	 * remains set until we return to user mode.

	 */

	if (task_thread_info(task)->status & TS_COMPAT)

		/*

		 * Sign-extend the value so (int)-EFOO becomes (long)-EFOO

		 * and will match correctly in comparisons.

		 */

		error = (long) (int) error;

#endif

	return IS_ERR_VALUE(error) ? error : 0;

}

static inline long syscall_get_return_value(struct task_struct *task,

					    struct pt_regs *regs)

{

	return regs->ax;

}

static inline void syscall_set_return_value(struct task_struct *task,

					    struct pt_regs *regs,

					    int error, long val)

{

	regs->ax = (long) error ?: val;

}

#ifdef CONFIG_X86_32

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);

	memcpy(args, &regs->bx + 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->bx + i, args, n * sizeof(args[0]));

}

#else	 /* CONFIG_X86_64 */

static inline void syscall_get_arguments(struct task_struct *task,

					 struct pt_regs *regs,

					 unsigned int i, unsigned int n,

					 unsigned long *args)

{

# ifdef CONFIG_IA32_EMULATION

	if (task_thread_info(task)->status & TS_COMPAT)

		switch (i) {

		case 0:

			if (!n--) break;

			*args++ = regs->bx;

		case 1:

			if (!n--) break;

			*args++ = regs->cx;

		case 2:

			if (!n--) break;

			*args++ = regs->dx;

		case 3:

			if (!n--) break;

			*args++ = regs->si;

		case 4:

			if (!n--) break;

			*args++ = regs->di;

		case 5:

			if (!n--) break;

			*args++ = regs->bp;

		case 6:

			if (!n--) break;

		default:

			BUG();

			break;

		}

	else

# endif

		switch (i) {

		case 0:

			if (!n--) break;

			*args++ = regs->di;

		case 1:

			if (!n--) break;

			*args++ = regs->si;

		case 2:

			if (!n--) break;

			*args++ = regs->dx;

		case 3:

			if (!n--) break;

			*args++ = regs->r10;

		case 4:

			if (!n--) break;

			*args++ = regs->r8;

		case 5:

			if (!n--) break;

			*args++ = regs->r9;

		case 6:

			if (!n--) break;

		default:

			BUG();

			break;

		}

}

static inline void syscall_set_arguments(struct task_struct *task,

					 struct pt_regs *regs,

					 unsigned int i, unsigned int n,

					 const unsigned long *args)

{

# ifdef CONFIG_IA32_EMULATION

	if (task_thread_info(task)->status & TS_COMPAT)

		switch (i) {

		case 0:

			if (!n--) break;

			regs->bx = *args++;

		case 1:

			if (!n--) break;

			regs->cx = *args++;

		case 2:

			if (!n--) break;

			regs->dx = *args++;

		case 3:

			if (!n--) break;

			regs->si = *args++;

		case 4:

			if (!n--) break;

			regs->di = *args++;

		case 5:

			if (!n--) break;

			regs->bp = *args++;

		case 6:

			if (!n--) break;

		default:

			BUG();

			break;

		}

	else

# endif

		switch (i) {

		case 0:

			if (!n--) break;

			regs->di = *args++;

		case 1:

			if (!n--) break;

			regs->si = *args++;

		case 2:

			if (!n--) break;

			regs->dx = *args++;

		case 3:

			if (!n--) break;

			regs->r10 = *args++;

		case 4:

			if (!n--) break;

			regs->r8 = *args++;

		case 5:

			if (!n--) break;

			regs->r9 = *args++;

		case 6:

			if (!n--) break;

		default:

			BUG();

			break;

		}

}

#endif	/* CONFIG_X86_32 */

#endif	/* _ASM_X86_SYSCALL_H */