[PATCH v8 09/20] x86: mm: Add p?d_large() definitions

Steven Price
2019-04-03T14:17:52Z

walk_page_range() is going to be allowed to walk page tables other than
those of user space. For this it needs to know when it has reached a
'leaf' entry in the page tables. This information is provided by the
p?d_large() functions/macros.

For x86 we already have static inline functions, so simply add #defines
to prevent the generic versions (added in a later patch) from being
picked up.

We also need to add corresponding #undefs in dump_pagetables.c. This
code will be removed when x86 is switched over to using the generic
pagewalk code in a later patch.

Signed-off-by: Steven Price <steven.price@arm.com>
---
arch/x86/include/asm/pgtable.h | 5 +++++
arch/x86/mm/dump_pagetables.c | 3 +++
2 files changed, 8 insertions(+)

diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 2779ace16d23..0dd04cf6ebeb 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -222,6 +222,7 @@ static inline unsigned long pgd_pfn(pgd_t pgd)
return (pgd_val(pgd) & PTE_PFN_MASK) >> PAGE_SHIFT;
}

+#define p4d_large p4d_large
static inline int p4d_large(p4d_t p4d)
{
/* No 512 GiB pages yet */
@@ -230,6 +231,7 @@ static inline int p4d_large(p4d_t p4d)

#define pte_page(pte) pfn_to_page(pte_pfn(pte))

+#define pmd_large pmd_large
static inline int pmd_large(pmd_t pte)
{
return pmd_flags(pte) & _PAGE_PSE;
@@ -857,6 +859,7 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address);
}

+#define pud_large pud_large
static inline int pud_large(pud_t pud)
{
return (pud_val(pud) & (_PAGE_PSE | _PAGE_PRESENT)) ==
@@ -868,6 +871,7 @@ static inline int pud_bad(pud_t pud)
return (pud_flags(pud) & ~(_KERNPG_TABLE | _PAGE_USER)) != 0;
}
#else
+#define pud_large pud_large
static inline int pud_large(pud_t pud)
{
return 0;
@@ -1213,6 +1217,7 @@ static inline bool pgdp_maps_userspace(void *__ptr)
return (((ptr & ~PAGE_MASK) / sizeof(pgd_t)) < PGD_KERNEL_START);
}

+#define pgd_large pgd_large
static inline int pgd_large(pgd_t pgd) { return 0; }

#ifdef CONFIG_PAGE_TABLE_ISOLATION
diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
index ee8f8ab46941..ca270fb00805 100644
--- a/arch/x86/mm/dump_pagetables.c
+++ b/arch/x86/mm/dump_pagetables.c
@@ -432,6 +432,7 @@ static void walk_pmd_level(struct seq_file *m, struct pg_state *st, pud_t addr,

#else
#define walk_pmd_level(m,s,a,e,p) walk_pte_level(m,s,__pmd(pud_val(a)),e,p)
+#undef pud_large
#define pud_large(a) pmd_large(__pmd(pud_val(a)))
#define pud_none(a) pmd_none(__pmd(pud_val(a)))
#endif
@@ -467,6 +468,7 @@ static void walk_pud_level(struct seq_file *m, struct pg_state *st, p4d_t addr,

#else
#define walk_pud_level(m,s,a,e,p) walk_pmd_level(m,s,__pud(p4d_val(a)),e,p)
+#undef p4d_large
#define p4d_large(a) pud_large(__pud(p4d_val(a)))
#define p4d_none(a) pud_none(__pud(p4d_val(a)))
#endif
@@ -501,6 +503,7 @@ static void walk_p4d_level(struct seq_file *m, struct pg_state *st, pgd_t addr,
}
}

+#undef pgd_large
#define pgd_large(a) (pgtable_l5_enabled() ? pgd_large(a) : p4d_large(__p4d(pgd_val(a))))
#define pgd_none(a) (pgtable_l5_enabled() ? pgd_none(a) : p4d_none(__p4d(pgd_val(a))))

--
2.20.1