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    Subject[PATCH 3.16 001/305] x86/asm: Add pud/pmd mask interfaces to handle large PAT bit
    3.16.63-rc1 review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Toshi Kani <toshi.kani@hpe.com>

    commit 4be4c1fb9a754b100466ebaec50f825be0b2050b upstream.

    The PAT bit gets relocated to bit 12 when PUD and PMD mappings are
    used. This bit 12, however, is not covered by PTE_FLAGS_MASK, which
    is used for masking pfn and flags for all levels.

    Add pud/pmd mask interfaces to handle pfn and flags properly by using
    P?D_PAGE_MASK when PUD/PMD mappings are used, i.e. PSE bit is set.

    Suggested-by: Juergen Gross <jgross@suse.com>
    Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
    Cc: Andrew Morton <akpm@linux-foundation.org>
    Cc: Juergen Gross <jgross@suse.com>
    Cc: H. Peter Anvin <hpa@zytor.com>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Borislav Petkov <bp@alien8.de>
    Cc: Konrad Wilk <konrad.wilk@oracle.com>
    Cc: Robert Elliot <elliott@hpe.com>
    Cc: linux-mm@kvack.org
    Link: http://lkml.kernel.org/r/1442514264-12475-4-git-send-email-toshi.kani@hpe.com
    Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
    Signed-off-by: Wenkuan Wang <Wenkuan.Wang@windriver.com>
    Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
    ---
    arch/x86/include/asm/pgtable_types.h | 36 ++++++++++++++++++++++++++++++++++--
    1 file changed, 34 insertions(+), 2 deletions(-)

    --- a/arch/x86/include/asm/pgtable_types.h
    +++ b/arch/x86/include/asm/pgtable_types.h
    @@ -257,10 +257,10 @@

    #include <linux/types.h>

    -/* PTE_PFN_MASK extracts the PFN from a (pte|pmd|pud|pgd)val_t */
    +/* Extracts the PFN from a (pte|pmd|pud|pgd)val_t of a 4KB page */
    #define PTE_PFN_MASK ((pteval_t)PHYSICAL_PAGE_MASK)

    -/* PTE_FLAGS_MASK extracts the flags from a (pte|pmd|pud|pgd)val_t */
    +/* Extracts the flags from a (pte|pmd|pud|pgd)val_t of a 4KB page */
    #define PTE_FLAGS_MASK (~PTE_PFN_MASK)

    typedef struct pgprot { pgprotval_t pgprot; } pgprot_t;
    @@ -329,11 +329,43 @@ static inline pmdval_t native_pmd_val(pm
    }
    #endif

    +static inline pudval_t pud_pfn_mask(pud_t pud)
    +{
    + if (native_pud_val(pud) & _PAGE_PSE)
    + return PUD_PAGE_MASK & PHYSICAL_PAGE_MASK;
    + else
    + return PTE_PFN_MASK;
    +}
    +
    +static inline pudval_t pud_flags_mask(pud_t pud)
    +{
    + if (native_pud_val(pud) & _PAGE_PSE)
    + return ~(PUD_PAGE_MASK & (pudval_t)PHYSICAL_PAGE_MASK);
    + else
    + return ~PTE_PFN_MASK;
    +}
    +
    static inline pudval_t pud_flags(pud_t pud)
    {
    return native_pud_val(pud) & PTE_FLAGS_MASK;
    }

    +static inline pmdval_t pmd_pfn_mask(pmd_t pmd)
    +{
    + if (native_pmd_val(pmd) & _PAGE_PSE)
    + return PMD_PAGE_MASK & PHYSICAL_PAGE_MASK;
    + else
    + return PTE_PFN_MASK;
    +}
    +
    +static inline pmdval_t pmd_flags_mask(pmd_t pmd)
    +{
    + if (native_pmd_val(pmd) & _PAGE_PSE)
    + return ~(PMD_PAGE_MASK & (pmdval_t)PHYSICAL_PAGE_MASK);
    + else
    + return ~PTE_PFN_MASK;
    +}
    +
    static inline pmdval_t pmd_flags(pmd_t pmd)
    {
    return native_pmd_val(pmd) & PTE_FLAGS_MASK;
    \
     
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