redonkable/alistair23-linux
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x86: add set_memory_4k to pageattr.c

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Add a new function to force split large pages into 4k pages.
This is needed for some followup optimizations.

I had to add a new field to cpa_data to pass down the information
that try_preserve_large_page should not run.

Right now no set_page_4k() because I didn't need it and all the
specialized users I have in mind would be more comfortable with
pure addresses. I also didn't export it because it's unlikely
external code needs it.

Signed-off-by: Andi Kleen <ak@suse.de>
Cc: andreas.herrmann3@amd.com
Cc: mingo@elte.hu
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Andi Kleen 2008-03-12 03:53:29 +01:00 committed by Ingo Molnar
parent cc61503219
commit c9caa02c52
2 changed files with 17 additions and 4 deletions
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20
arch/x86/mm/pageattr.c
View file

@ -31,6 +31,7 @@ struct cpa_data {
int numpages;
int flushtlb;
unsigned long pfn;
unsigned force_split : 1;
};
#ifdef CONFIG_X86_64
@ -262,6 +263,9 @@ try_preserve_large_page(pte_t *kpte, unsigned long address,
int i, do_split = 1;
unsigned int level;
if (cpa->force_split)
return 1;
spin_lock_irqsave(&pgd_lock, flags);
/*
* Check for races, another CPU might have split this page
@ -696,7 +700,8 @@ static inline int cache_attr(pgprot_t attr)
}
static int change_page_attr_set_clr(unsigned long addr, int numpages,
pgprot_t mask_set, pgprot_t mask_clr)
pgprot_t mask_set, pgprot_t mask_clr,
int force_split)
{
struct cpa_data cpa;
int ret, cache, checkalias;
@ -707,7 +712,7 @@ static int change_page_attr_set_clr(unsigned long addr, int numpages,
*/
mask_set = canon_pgprot(mask_set);
mask_clr = canon_pgprot(mask_clr);
if (!pgprot_val(mask_set) && !pgprot_val(mask_clr))
if (!pgprot_val(mask_set) && !pgprot_val(mask_clr) && !force_split)
return 0;
/* Ensure we are PAGE_SIZE aligned */
@ -724,6 +729,7 @@ static int change_page_attr_set_clr(unsigned long addr, int numpages,
cpa.mask_set = mask_set;
cpa.mask_clr = mask_clr;
cpa.flushtlb = 0;
cpa.force_split = force_split;
/* No alias checking for _NX bit modifications */
checkalias = (pgprot_val(mask_set) | pgprot_val(mask_clr)) != _PAGE_NX;
@ -762,13 +768,13 @@ out:
static inline int change_page_attr_set(unsigned long addr, int numpages,
pgprot_t mask)
{
return change_page_attr_set_clr(addr, numpages, mask, __pgprot(0));
return change_page_attr_set_clr(addr, numpages, mask, __pgprot(0), 0);
}
static inline int change_page_attr_clear(unsigned long addr, int numpages,
pgprot_t mask)
{
return change_page_attr_set_clr(addr, numpages, __pgprot(0), mask);
return change_page_attr_set_clr(addr, numpages, __pgprot(0), mask, 0);
}
int _set_memory_uc(unsigned long addr, int numpages)
@ -847,6 +853,12 @@ int set_memory_np(unsigned long addr, int numpages)
return change_page_attr_clear(addr, numpages, __pgprot(_PAGE_PRESENT));
}
int set_memory_4k(unsigned long addr, int numpages)
{
return change_page_attr_set_clr(addr, numpages, __pgprot(0),
__pgprot(0), 1);
}
int set_pages_uc(struct page *page, int numpages)
{
unsigned long addr = (unsigned long)page_address(page);

1
include/asm-x86/cacheflush.h
View file

@ -45,6 +45,7 @@ int set_memory_nx(unsigned long addr, int numpages);
int set_memory_ro(unsigned long addr, int numpages);
int set_memory_rw(unsigned long addr, int numpages);
int set_memory_np(unsigned long addr, int numpages);
int set_memory_4k(unsigned long addr, int numpages);
void clflush_cache_range(void *addr, unsigned int size);