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Commit 7747b9a4 authored by Paul Mundt's avatar Paul Mundt
Browse files

sh: Wire up clear_user_highpage(). 



With the kmap_coherent() API in place, this is trivial to implement,
and lets us avoid the cache flush in certain cases.

Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent f9669187

arch/sh/mm/pg-sh4.c

+23 −0
Original line number Diff line number Diff line
@@ -9,6 +9,8 @@ 
#include <linux/mm.h>

#include <linux/mutex.h>

#include <linux/fs.h>

#include <linux/highmem.h>

#include <linux/module.h>

#include <asm/mmu_context.h>

#include <asm/cacheflush.h>
@@ -79,6 +81,27 @@ void copy_user_page(void *to, void *from, unsigned long address, 
	}

}



void copy_user_highpage(struct page *to, struct page *from,

			unsigned long vaddr, struct vm_area_struct *vma)

{

	void *vfrom, *vto;



	__set_bit(PG_mapped, &to->flags);



	vto = kmap_atomic(to, KM_USER1);

	vfrom = kmap_coherent(from, vaddr);

	copy_page(vto, vfrom);

	kunmap_coherent(vfrom);



	if (((vaddr ^ (unsigned long)vto) & CACHE_ALIAS))

		__flush_wback_region(vto, PAGE_SIZE);



	kunmap_atomic(vto, KM_USER1);

	/* Make sure this page is cleared on other CPU's too before using it */

	smp_wmb();

}

EXPORT_SYMBOL(copy_user_highpage);



/*

 * For SH-4, we have our own implementation for ptep_get_and_clear

 */

include/asm-sh/page.h

+6 −0
Original line number Diff line number Diff line
@@ -73,10 +73,16 @@ extern void copy_page_nommu(void *to, void *from); 
#if !defined(CONFIG_CACHE_OFF) && defined(CONFIG_MMU) && \

	(defined(CONFIG_CPU_SH4) || defined(CONFIG_SH7705_CACHE_32KB))

struct page;

struct vm_area_struct;

extern void clear_user_page(void *to, unsigned long address, struct page *pg);

extern void copy_user_page(void *to, void *from, unsigned long address, struct page *pg);

extern void __clear_user_page(void *to, void *orig_to);

extern void __copy_user_page(void *to, void *from, void *orig_to);

#ifdef CONFIG_CPU_SH4

extern void copy_user_highpage(struct page *to, struct page *from,

			       unsigned long vaddr, struct vm_area_struct *vma);

#define __HAVE_ARCH_COPY_USER_HIGHPAGE

#endif

#else

#define clear_user_page(page, vaddr, pg)	clear_page(page)

#define copy_user_page(to, from, vaddr, pg)	copy_page(to, from)