Commit bd79f947 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Arnd Bergmann
Browse files

asm-generic: provide entirely generic nommu uaccess 



Move the code to implement uaccess using memcpy or direct loads and
stores to asm-generic/uaccess.h and make it selectable kconfig option.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
parent c67fdc1f

arch/h8300/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ config H8300 
	select HAVE_ARCH_KGDB

	select HAVE_ARCH_HASH

	select CPU_NO_EFFICIENT_FFS

	select UACCESS_MEMCPY



config CPU_BIG_ENDIAN

	def_bool y

arch/h8300/include/asm/Kbuild

+1 −0
Original line number Diff line number Diff line
@@ -46,6 +46,7 @@ generic-y += timex.h 
generic-y += tlbflush.h

generic-y += topology.h

generic-y += trace_clock.h

generic-y += uaccess.h

generic-y += unaligned.h

generic-y += vga.h

generic-y += word-at-a-time.h

arch/h8300/include/asm/uaccess.h

deleted100644 → 0
+0 −55
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

#ifndef _ASM_UACCESS_H

#define _ASM_UACCESS_H



#include <linux/string.h>



static inline __must_check unsigned long

raw_copy_from_user(void *to, const void __user * from, unsigned long n)

{

	if (__builtin_constant_p(n)) {

		switch(n) {

		case 1:

			*(u8 *)to = *(u8 __force *)from;

			return 0;

		case 2:

			*(u16 *)to = *(u16 __force *)from;

			return 0;

		case 4:

			*(u32 *)to = *(u32 __force *)from;

			return 0;

		}

	}



	memcpy(to, (const void __force *)from, n);

	return 0;

}



static inline __must_check unsigned long

raw_copy_to_user(void __user *to, const void *from, unsigned long n)

{

	if (__builtin_constant_p(n)) {

		switch(n) {

		case 1:

			*(u8 __force *)to = *(u8 *)from;

			return 0;

		case 2:

			*(u16 __force *)to = *(u16 *)from;

			return 0;

		case 4:

			*(u32 __force *)to = *(u32 *)from;

			return 0;

		default:

			break;

		}

	}



	memcpy((void __force *)to, from, n);

	return 0;

}

#define INLINE_COPY_FROM_USER

#define INLINE_COPY_TO_USER



#include <asm-generic/uaccess.h>



#endif

include/asm-generic/uaccess.h

+48 −0
Original line number Diff line number Diff line
@@ -9,6 +9,54 @@ 
 */

#include <linux/string.h>



#ifdef CONFIG_UACCESS_MEMCPY

static inline __must_check unsigned long

raw_copy_from_user(void *to, const void __user * from, unsigned long n)

{

	if (__builtin_constant_p(n)) {

		switch(n) {

		case 1:

			*(u8 *)to = *(u8 __force *)from;

			return 0;

		case 2:

			*(u16 *)to = *(u16 __force *)from;

			return 0;

		case 4:

			*(u32 *)to = *(u32 __force *)from;

			return 0;

		}

	}



	memcpy(to, (const void __force *)from, n);

	return 0;

}



static inline __must_check unsigned long

raw_copy_to_user(void __user *to, const void *from, unsigned long n)

{

	if (__builtin_constant_p(n)) {

		switch(n) {

		case 1:

			*(u8 __force *)to = *(u8 *)from;

			return 0;

		case 2:

			*(u16 __force *)to = *(u16 *)from;

			return 0;

		case 4:

			*(u32 __force *)to = *(u32 *)from;

			return 0;

		default:

			break;

		}

	}



	memcpy((void __force *)to, from, n);

	return 0;

}

#define INLINE_COPY_FROM_USER

#define INLINE_COPY_TO_USER

#endif /* CONFIG_UACCESS_MEMCPY */



#define MAKE_MM_SEG(s)	((mm_segment_t) { (s) })



#ifndef KERNEL_DS

lib/Kconfig

+4 −0
Original line number Diff line number Diff line
@@ -591,6 +591,10 @@ config ARCH_NO_SG_CHAIN 
config ARCH_HAS_PMEM_API

	bool



# use memcpy to implement user copies for nommu architectures

config UACCESS_MEMCPY

	bool



config ARCH_HAS_UACCESS_FLUSHCACHE

	bool