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Subject[PATCH v2 3/4] x86: Fix pud/pmd interfaces to handle large PAT bit
Date
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 corrently used for masking pfn and flags for all cases.

Fix pud/pmd 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@hp.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Konrad Wilk <konrad.wilk@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
arch/x86/include/asm/pgtable.h | 14 +++++++-----
arch/x86/include/asm/pgtable_types.h | 40 +++++++++++++++++++++++++++++++---
2 files changed, 44 insertions(+), 10 deletions(-)

diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 867da5b..0733ec7 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -142,12 +142,12 @@ static inline unsigned long pte_pfn(pte_t pte)

static inline unsigned long pmd_pfn(pmd_t pmd)
{
- return (pmd_val(pmd) & PTE_PFN_MASK) >> PAGE_SHIFT;
+ return (pmd_val(pmd) & pmd_pfn_mask(pmd)) >> PAGE_SHIFT;
}

static inline unsigned long pud_pfn(pud_t pud)
{
- return (pud_val(pud) & PTE_PFN_MASK) >> PAGE_SHIFT;
+ return (pud_val(pud) & pud_pfn_mask(pud)) >> PAGE_SHIFT;
}

#define pte_page(pte) pfn_to_page(pte_pfn(pte))
@@ -502,14 +502,15 @@ static inline int pmd_none(pmd_t pmd)

static inline unsigned long pmd_page_vaddr(pmd_t pmd)
{
- return (unsigned long)__va(pmd_val(pmd) & PTE_PFN_MASK);
+ return (unsigned long)__va(pmd_val(pmd) & pmd_pfn_mask(pmd));
}

/*
* Currently stuck as a macro due to indirect forward reference to
* linux/mmzone.h's __section_mem_map_addr() definition:
*/
-#define pmd_page(pmd) pfn_to_page((pmd_val(pmd) & PTE_PFN_MASK) >> PAGE_SHIFT)
+#define pmd_page(pmd) \
+ pfn_to_page((pmd_val(pmd) & pmd_pfn_mask(pmd)) >> PAGE_SHIFT)

/*
* the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
@@ -570,14 +571,15 @@ static inline int pud_present(pud_t pud)

static inline unsigned long pud_page_vaddr(pud_t pud)
{
- return (unsigned long)__va((unsigned long)pud_val(pud) & PTE_PFN_MASK);
+ return (unsigned long)__va(pud_val(pud) & pud_pfn_mask(pud));
}

/*
* Currently stuck as a macro due to indirect forward reference to
* linux/mmzone.h's __section_mem_map_addr() definition:
*/
-#define pud_page(pud) pfn_to_page(pud_val(pud) >> PAGE_SHIFT)
+#define pud_page(pud) \
+ pfn_to_page((pud_val(pud) & pud_pfn_mask(pud)) >> PAGE_SHIFT)

/* Find an entry in the second-level page table.. */
static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
index 13f310b..dd5b0aa 100644
--- a/arch/x86/include/asm/pgtable_types.h
+++ b/arch/x86/include/asm/pgtable_types.h
@@ -209,10 +209,10 @@ enum page_cache_mode {

#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;
@@ -276,14 +276,46 @@ static inline pmdval_t native_pmd_val(pmd_t pmd)
}
#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;
+ return native_pud_val(pud) & pud_flags_mask(pud);
+}
+
+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;
+ return native_pmd_val(pmd) & pmd_flags_mask(pmd);
}

static inline pte_t native_make_pte(pteval_t val)

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