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x86/mm/pageattr: Add a PUD pagetable populating function 

Add the next level of the pagetable populating function, we handle
chunks around a 1G boundary by mapping them with the lower level
functions - otherwise we use 1G pages for the mappings, thus using as
less amount of pagetable pages as possible.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
This commit is contained in:
Borislav Petkov 2013-10-31 17:25:02 +01:00 committed by Matt Fleming
parent f3f729661e
commit 4b23538d88
1 changed files with 86 additions and 1 deletions
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87
arch/x86/mm/pageattr.c
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@ -666,7 +666,92 @@ static int split_large_page(pte_t *kpte, unsigned long address)
return 0;
}
#define populate_pud(cpa, addr, pgd, pgprot) (-1)
static int alloc_pmd_page(pud_t *pud)
{
pmd_t *pmd = (pmd_t *)get_zeroed_page(GFP_KERNEL | __GFP_NOTRACK);
if (!pmd)
return -1;
set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));
return 0;
}
#define populate_pmd(cpa, start, end, pages, pud, pgprot) (-1)
static int populate_pud(struct cpa_data *cpa, unsigned long start, pgd_t *pgd,
pgprot_t pgprot)
{
pud_t *pud;
unsigned long end;
int cur_pages = 0;
end = start + (cpa->numpages << PAGE_SHIFT);
/*
* Not on a Gb page boundary? => map everything up to it with
* smaller pages.
*/
if (start & (PUD_SIZE - 1)) {
unsigned long pre_end;
unsigned long next_page = (start + PUD_SIZE) & PUD_MASK;
pre_end = min_t(unsigned long, end, next_page);
cur_pages = (pre_end - start) >> PAGE_SHIFT;
cur_pages = min_t(int, (int)cpa->numpages, cur_pages);
pud = pud_offset(pgd, start);
/*
* Need a PMD page?
*/
if (pud_none(*pud))
if (alloc_pmd_page(pud))
return -1;
cur_pages = populate_pmd(cpa, start, pre_end, cur_pages,
pud, pgprot);
if (cur_pages < 0)
return cur_pages;
start = pre_end;
}
/* We mapped them all? */
if (cpa->numpages == cur_pages)
return cur_pages;
pud = pud_offset(pgd, start);
/*
* Map everything starting from the Gb boundary, possibly with 1G pages
*/
while (end - start >= PUD_SIZE) {
set_pud(pud, __pud(cpa->pfn | _PAGE_PSE | massage_pgprot(pgprot)));
start += PUD_SIZE;
cpa->pfn += PUD_SIZE;
cur_pages += PUD_SIZE >> PAGE_SHIFT;
pud++;
}
/* Map trailing leftover */
if (start < end) {
int tmp;
pud = pud_offset(pgd, start);
if (pud_none(*pud))
if (alloc_pmd_page(pud))
return -1;
tmp = populate_pmd(cpa, start, end, cpa->numpages - cur_pages,
pud, pgprot);
if (tmp < 0)
return cur_pages;
cur_pages += tmp;
}
return cur_pages;
}
/*
* Restrictions for kernel page table do not necessarily apply when mapping in