linux-kernel - [PATCH v7 09/20] x86: mm: Add p?d

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Date:   Thu, 28 Mar 2019 15:20:53 +0000
From:   Steven Price <steven.price@....com>
To:     linux-mm@...ck.org
Cc:     Steven Price <steven.price@....com>,
        Andy Lutomirski <luto@...nel.org>,
        Ard Biesheuvel <ard.biesheuvel@...aro.org>,
        Arnd Bergmann <arnd@...db.de>, Borislav Petkov <bp@...en8.de>,
        Catalin Marinas <catalin.marinas@....com>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Ingo Molnar <mingo@...hat.com>,
        James Morse <james.morse@....com>,
        Jérôme Glisse <jglisse@...hat.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Will Deacon <will.deacon@....com>, x86@...nel.org,
        "H. Peter Anvin" <hpa@...or.com>,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Mark Rutland <Mark.Rutland@....com>,
        "Liang, Kan" <kan.liang@...ux.intel.com>
Subject: [PATCH v7 09/20] x86: mm: Add p?d_large() definitions

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@....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