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| author | Juergen Gross <jgross@suse.com> | 2014-11-28 13:53:56 +0300 |
|---|---|---|
| committer | David Vrabel <david.vrabel@citrix.com> | 2014-12-04 17:09:04 +0300 |
| commit | 792230c3a66b3d17d6dcca712866d24f2283d4a6 (patch) | |
| tree | 8afc8973622985092d2a0913a6ba53028d625b39 /arch/x86/mm | |
| parent | 5b8e7d80542487ff1bf17b4cf2922a01dee13d3a (diff) | |
| download | linux-792230c3a66b3d17d6dcca712866d24f2283d4a6.tar.xz | |
x86: Introduce function to get pmd entry pointer
Introduces lookup_pmd_address() to get the address of the pmd entry
related to a virtual address in the current address space. This
function is needed for support of a virtual mapped sparse p2m list
in xen pv domains, as we need the address of the pmd entry, not the
one of the pte in that case.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Diffstat (limited to 'arch/x86/mm')
| -rw-r--r-- | arch/x86/mm/pageattr.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 36de293caf25..129810887e83 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -384,6 +384,26 @@ static pte_t *_lookup_address_cpa(struct cpa_data *cpa, unsigned long address, } /* + * Lookup the PMD entry for a virtual address. Return a pointer to the entry + * or NULL if not present. + */ +pmd_t *lookup_pmd_address(unsigned long address) +{ + pgd_t *pgd; + pud_t *pud; + + pgd = pgd_offset_k(address); + if (pgd_none(*pgd)) + return NULL; + + pud = pud_offset(pgd, address); + if (pud_none(*pud) || pud_large(*pud) || !pud_present(*pud)) + return NULL; + + return pmd_offset(pud, address); +} + +/* * This is necessary because __pa() does not work on some * kinds of memory, like vmalloc() or the alloc_remap() * areas on 32-bit NUMA systems. The percpu areas can |