linux-kernel - [PATCH 02/13] x86/mm: Add p?d

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Date:   Fri, 15 Feb 2019 17:02:23 +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
Subject: [PATCH 02/13] x86/mm: Add p?d_large() definitions

Exposing the pud/pgd levels of the page tables to walk_page_range() means
we may come across the exotic large mappings that come with large areas
of contiguous memory (such as the kernel's linear map).

Expose p?d_large() from each architecture to detect these large mappings.

x86 already has these defined as inline functions, add a macro of the
same name so we don't end up with the generic version too.

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

diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 2779ace16d23..3695f6acb6af 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -234,6 +234,7 @@ static inline int pmd_large(pmd_t pte)
 {
 	return pmd_flags(pte) & _PAGE_PSE;
 }
+#define pmd_large(x)	pmd_large(x)
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 static inline int pmd_trans_huge(pmd_t pmd)
@@ -873,6 +874,7 @@ static inline int pud_large(pud_t pud)
 	return 0;
 }
 #endif	/* CONFIG_PGTABLE_LEVELS > 2 */
+#define pud_large(x)	pud_large(x)
 
 static inline unsigned long pud_index(unsigned long address)
 {
@@ -1214,6 +1216,7 @@ static inline bool pgdp_maps_userspace(void *__ptr)
 }
 
 static inline int pgd_large(pgd_t pgd) { return 0; }
+#define pgd_large(x)	pgd_large(x)
 
 #ifdef CONFIG_PAGE_TABLE_ISOLATION
 /*
diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
index e3cdc85ce5b6..695647dc9cb9 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
@@ -503,6 +504,7 @@ 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