#ifndef _ASM_X86_UACCESS_64_H
#define _ASM_X86_UACCESS_64_H

/*
 * User space memory access functions
 */
#include <linux/compiler.h>
#include <linux/errno.h>
#include <linux/lockdep.h>
#include <linux/kasan-checks.h>
#include <asm/alternative.h>
#include <asm/cpufeatures.h>
#include <asm/page.h>

/*
 * Copy To/From Userspace
 */

/* Handles exceptions in both to and from, but doesn't do access_ok */
__must_check unsigned long
copy_user_enhanced_fast_string(void *to, const void *from, unsigned len);
__must_check unsigned long
copy_user_generic_string(void *to, const void *from, unsigned len);
__must_check unsigned long
copy_user_generic_unrolled(void *to, const void *from, unsigned len);

static __always_inline __must_check unsigned long
copy_user_generic(void *to, const void *from, unsigned len)
{
	unsigned ret;

	/*
	 * If CPU has ERMS feature, use copy_user_enhanced_fast_string.
	 * Otherwise, if CPU has rep_good feature, use copy_user_generic_string.
	 * Otherwise, use copy_user_generic_unrolled.
	 */
	alternative_call_2(copy_user_generic_unrolled,
					   copy_user_generic_string,
					   X86_FEATURE_REP_GOOD,
					   copy_user_enhanced_fast_string,
					   X86_FEATURE_ERMS,
					   ASM_OUTPUT2("=a" (ret), "=D" (to), "=S" (from),
								   "=d" (len)),
					   "1" (to), "2" (from), "3" (len)
					   : "memory", "rcx", "r8", "r9", "r10", "r11");
	return ret;
}

__must_check unsigned long
copy_in_user(void __user *to, const void __user *from, unsigned len);

static __always_inline __must_check
int __copy_from_user_nocheck(void *dst, const void __user *src, unsigned size)
{
	int ret = 0;

	check_object_size(dst, size, false);

	if (!__builtin_constant_p(size))
	{
		return copy_user_generic(dst, (__force void *)src, size);
	}

	switch (size)
	{
		case 1:
			__uaccess_begin();
			__get_user_asm(*(u8 *)dst, (u8 __user *)src,
						   ret, "b", "b", "=q", 1);
			__uaccess_end();
			return ret;

		case 2:
			__uaccess_begin();
			__get_user_asm(*(u16 *)dst, (u16 __user *)src,
						   ret, "w", "w", "=r", 2);
			__uaccess_end();
			return ret;

		case 4:
			__uaccess_begin();
			__get_user_asm(*(u32 *)dst, (u32 __user *)src,
						   ret, "l", "k", "=r", 4);
			__uaccess_end();
			return ret;

		case 8:
			__uaccess_begin();
			__get_user_asm(*(u64 *)dst, (u64 __user *)src,
						   ret, "q", "", "=r", 8);
			__uaccess_end();
			return ret;

		case 10:
			__uaccess_begin();
			__get_user_asm(*(u64 *)dst, (u64 __user *)src,
						   ret, "q", "", "=r", 10);

			if (likely(!ret))
				__get_user_asm(*(u16 *)(8 + (char *)dst),
							   (u16 __user *)(8 + (char __user *)src),
							   ret, "w", "w", "=r", 2);

			__uaccess_end();
			return ret;

		case 16:
			__uaccess_begin();
			__get_user_asm(*(u64 *)dst, (u64 __user *)src,
						   ret, "q", "", "=r", 16);

			if (likely(!ret))
				__get_user_asm(*(u64 *)(8 + (char *)dst),
							   (u64 __user *)(8 + (char __user *)src),
							   ret, "q", "", "=r", 8);

			__uaccess_end();
			return ret;

		default:
			return copy_user_generic(dst, (__force void *)src, size);
	}
}

static __always_inline __must_check
int __copy_from_user(void *dst, const void __user *src, unsigned size)
{
	might_fault();
	kasan_check_write(dst, size);
	return __copy_from_user_nocheck(dst, src, size);
}

static __always_inline __must_check
int __copy_to_user_nocheck(void __user *dst, const void *src, unsigned size)
{
	int ret = 0;

	check_object_size(src, size, true);

	if (!__builtin_constant_p(size))
	{
		return copy_user_generic((__force void *)dst, src, size);
	}

	switch (size)
	{
		case 1:
			__uaccess_begin();
			__put_user_asm(*(u8 *)src, (u8 __user *)dst,
						   ret, "b", "b", "iq", 1);
			__uaccess_end();
			return ret;

		case 2:
			__uaccess_begin();
			__put_user_asm(*(u16 *)src, (u16 __user *)dst,
						   ret, "w", "w", "ir", 2);
			__uaccess_end();
			return ret;

		case 4:
			__uaccess_begin();
			__put_user_asm(*(u32 *)src, (u32 __user *)dst,
						   ret, "l", "k", "ir", 4);
			__uaccess_end();
			return ret;

		case 8:
			__uaccess_begin();
			__put_user_asm(*(u64 *)src, (u64 __user *)dst,
						   ret, "q", "", "er", 8);
			__uaccess_end();
			return ret;

		case 10:
			__uaccess_begin();
			__put_user_asm(*(u64 *)src, (u64 __user *)dst,
						   ret, "q", "", "er", 10);

			if (likely(!ret))
			{
				asm("":::"memory");
				__put_user_asm(4[(u16 *)src], 4 + (u16 __user *)dst,
							   ret, "w", "w", "ir", 2);
			}

			__uaccess_end();
			return ret;

		case 16:
			__uaccess_begin();
			__put_user_asm(*(u64 *)src, (u64 __user *)dst,
						   ret, "q", "", "er", 16);

			if (likely(!ret))
			{
				asm("":::"memory");
				__put_user_asm(1[(u64 *)src], 1 + (u64 __user *)dst,
							   ret, "q", "", "er", 8);
			}

			__uaccess_end();
			return ret;

		default:
			return copy_user_generic((__force void *)dst, src, size);
	}
}

static __always_inline __must_check
int __copy_to_user(void __user *dst, const void *src, unsigned size)
{
	might_fault();
	kasan_check_read(src, size);
	return __copy_to_user_nocheck(dst, src, size);
}

static __always_inline __must_check
int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
{
	int ret = 0;

	might_fault();

	if (!__builtin_constant_p(size))
		return copy_user_generic((__force void *)dst,
								 (__force void *)src, size);

	switch (size)
	{
		case 1:
			{
				u8 tmp;
				__uaccess_begin();
				__get_user_asm(tmp, (u8 __user *)src,
							   ret, "b", "b", "=q", 1);

				if (likely(!ret))
					__put_user_asm(tmp, (u8 __user *)dst,
								   ret, "b", "b", "iq", 1);

				__uaccess_end();
				return ret;
			}

		case 2:
			{
				u16 tmp;
				__uaccess_begin();
				__get_user_asm(tmp, (u16 __user *)src,
							   ret, "w", "w", "=r", 2);

				if (likely(!ret))
					__put_user_asm(tmp, (u16 __user *)dst,
								   ret, "w", "w", "ir", 2);

				__uaccess_end();
				return ret;
			}

		case 4:
			{
				u32 tmp;
				__uaccess_begin();
				__get_user_asm(tmp, (u32 __user *)src,
							   ret, "l", "k", "=r", 4);

				if (likely(!ret))
					__put_user_asm(tmp, (u32 __user *)dst,
								   ret, "l", "k", "ir", 4);

				__uaccess_end();
				return ret;
			}

		case 8:
			{
				u64 tmp;
				__uaccess_begin();
				__get_user_asm(tmp, (u64 __user *)src,
							   ret, "q", "", "=r", 8);

				if (likely(!ret))
					__put_user_asm(tmp, (u64 __user *)dst,
								   ret, "q", "", "er", 8);

				__uaccess_end();
				return ret;
			}

		default:
			return copy_user_generic((__force void *)dst,
									 (__force void *)src, size);
	}
}

static __must_check __always_inline int
__copy_from_user_inatomic(void *dst, const void __user *src, unsigned size)
{
	kasan_check_write(dst, size);
	return __copy_from_user_nocheck(dst, src, size);
}

static __must_check __always_inline int
__copy_to_user_inatomic(void __user *dst, const void *src, unsigned size)
{
	kasan_check_read(src, size);
	return __copy_to_user_nocheck(dst, src, size);
}

extern long __copy_user_nocache(void *dst, const void __user *src,
								unsigned size, int zerorest);

static inline int
__copy_from_user_nocache(void *dst, const void __user *src, unsigned size)
{
	might_fault();
	kasan_check_write(dst, size);
	return __copy_user_nocache(dst, src, size, 1);
}

static inline int
__copy_from_user_inatomic_nocache(void *dst, const void __user *src,
								  unsigned size)
{
	kasan_check_write(dst, size);
	return __copy_user_nocache(dst, src, size, 0);
}

unsigned long
copy_user_handle_tail(char *to, char *from, unsigned len);

#endif /* _ASM_X86_UACCESS_64_H */
