Commit 1ac2f7d5 authored by Shaohua Li's avatar Shaohua Li Committed by Ingo Molnar
Browse files

introduce two APIs for page attribute 



Introduce two APIs for page attribute. flushing tlb/cache in every page
attribute is expensive. AGP gart usually will do a lot of operations to
change a page to uc, new APIs can reduce flush.

Signed-off-by: default avatarShaohua Li <shaohua.li@intel.com>
Cc: airlied@linux.ie
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 012f09e7

arch/x86/mm/pageattr.c

+50 −8
Original line number Diff line number Diff line
@@ -752,12 +752,12 @@ static inline int cache_attr(pgprot_t attr) 
		(_PAGE_PAT | _PAGE_PAT_LARGE | _PAGE_PWT | _PAGE_PCD);

}



static int change_page_attr_set_clr(unsigned long addr, int numpages,

static int do_change_page_attr_set_clr(unsigned long addr, int numpages,

				    pgprot_t mask_set, pgprot_t mask_clr,

				    int force_split)

				    int force_split, int *tlb_flush)

{

	struct cpa_data cpa;

	int ret, cache, checkalias;

	int ret, checkalias;



	/*

	 * Check, if we are requested to change a not supported
@@ -792,9 +792,22 @@ static int change_page_attr_set_clr(unsigned long addr, int numpages, 
	/*

	 * Check whether we really changed something:

	 */

	if (!cpa.flushtlb)

		goto out;

	*tlb_flush = cpa.flushtlb;

	cpa_fill_pool(NULL);



	return ret;

}



static int change_page_attr_set_clr(unsigned long addr, int numpages,

				    pgprot_t mask_set, pgprot_t mask_clr,

				    int force_split)

{

	int cache, flush_cache = 0, ret;



	ret = do_change_page_attr_set_clr(addr, numpages, mask_set, mask_clr,

		force_split, &flush_cache);

	if (!flush_cache)

		goto out;

	/*

	 * No need to flush, when we did not set any of the caching

	 * attributes:
@@ -811,10 +824,7 @@ static int change_page_attr_set_clr(unsigned long addr, int numpages, 
		cpa_flush_range(addr, numpages, cache);

	else

		cpa_flush_all(cache);



out:

	cpa_fill_pool(NULL);



	return ret;

}
@@ -852,6 +862,30 @@ int set_memory_uc(unsigned long addr, int numpages) 
}

EXPORT_SYMBOL(set_memory_uc);



int set_memory_uc_noflush(unsigned long addr, int numpages)

{

	int flush;

	/*

	 * for now UC MINUS. see comments in ioremap_nocache()

	 */

	if (reserve_memtype(addr, addr + numpages * PAGE_SIZE,

			    _PAGE_CACHE_UC_MINUS, NULL))

		return -EINVAL;

	/*

	 * for now UC MINUS. see comments in ioremap_nocache()

	 */

	return do_change_page_attr_set_clr(addr, numpages,

				    __pgprot(_PAGE_CACHE_UC_MINUS),

					__pgprot(0), 0, &flush);

}

EXPORT_SYMBOL(set_memory_uc_noflush);



void set_memory_flush_all(void)

{

	cpa_flush_all(1);

}

EXPORT_SYMBOL(set_memory_flush_all);



int _set_memory_wc(unsigned long addr, int numpages)

{

	return change_page_attr_set(addr, numpages,
@@ -926,6 +960,14 @@ int set_pages_uc(struct page *page, int numpages) 
}

EXPORT_SYMBOL(set_pages_uc);



int set_pages_uc_noflush(struct page *page, int numpages)

{

	unsigned long addr = (unsigned long)page_address(page);



	return set_memory_uc_noflush(addr, numpages);

}

EXPORT_SYMBOL(set_pages_uc_noflush);



int set_pages_wb(struct page *page, int numpages)

{

	unsigned long addr = (unsigned long)page_address(page);

include/asm-x86/cacheflush.h

+3 −0
Original line number Diff line number Diff line
@@ -57,6 +57,8 @@ int _set_memory_uc(unsigned long addr, int numpages); 
int _set_memory_wc(unsigned long addr, int numpages);

int _set_memory_wb(unsigned long addr, int numpages);

int set_memory_uc(unsigned long addr, int numpages);

int set_memory_uc_noflush(unsigned long addr, int numpages);

void set_memory_flush_all(void);

int set_memory_wc(unsigned long addr, int numpages);

int set_memory_wb(unsigned long addr, int numpages);

int set_memory_x(unsigned long addr, int numpages);
@@ -87,6 +89,7 @@ int set_memory_4k(unsigned long addr, int numpages); 
 */



int set_pages_uc(struct page *page, int numpages);

int set_pages_uc_noflush(struct page *page, int numpages);

int set_pages_wb(struct page *page, int numpages);

int set_pages_x(struct page *page, int numpages);

int set_pages_nx(struct page *page, int numpages);