From b9820d8f39f816b67112eb7ec5cdc4c1655ff060 Mon Sep 17 00:00:00 2001
From: Toshi Kani <toshi.kani@hp.com>
Date: Tue, 14 Apr 2015 15:47:26 -0700
Subject: [PATCH] mm: change vunmap to tear down huge KVA mappings
Change vunmap_pmd_range() and vunmap_pud_range() to tear down huge KVA
mappings when they are set. pud_clear_huge() and pmd_clear_huge() return
zero when no-operation is performed, i.e. huge page mapping was not used.
These changes are only enabled when CONFIG_HAVE_ARCH_HUGE_VMAP is defined
on the architecture.
[akpm@linux-foundation.org: use consistent code layout]
Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Robert Elliott <Elliott@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
include/asm-generic/pgtable.h | 10 ++++++++++
mm/vmalloc.c | 4 ++++
2 files changed, 14 insertions(+)
diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index 9fb7dc7ca7f4..39f1d6a2b04d 100644
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -700,6 +700,8 @@ static inline int pmd_protnone(pmd_t pmd)
#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot);
int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot);
+int pud_clear_huge(pud_t *pud);
+int pmd_clear_huge(pmd_t *pmd);
#else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
static inline int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot)
{
@@ -709,6 +711,14 @@ static inline int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot)
{
return 0;
}
+static inline int pud_clear_huge(pud_t *pud)
+{
+ return 0;
+}
+static inline int pmd_clear_huge(pmd_t *pmd)
+{
+ return 0;
+}
#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
#endif /* !__ASSEMBLY__ */
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index a48cd061f16f..a5bbdd3b5d67 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -75,6 +75,8 @@ static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end)
pmd = pmd_offset(pud, addr);
do {
next = pmd_addr_end(addr, end);
+ if (pmd_clear_huge(pmd))
+ continue;
if (pmd_none_or_clear_bad(pmd))
continue;
vunmap_pte_range(pmd, addr, next);
@@ -89,6 +91,8 @@ static void vunmap_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end)
pud = pud_offset(pgd, addr);
do {
next = pud_addr_end(addr, end);
+ if (pud_clear_huge(pud))
+ continue;
if (pud_none_or_clear_bad(pud))
continue;
vunmap_pmd_range(pud, addr, next);