[PATCH v2 4/4] ARM: mm: Transparent huge page support for LPAE systems.
Steve Capper
steve.capper at linaro.org
Thu May 23 11:31:20 EDT 2013
From: Catalin Marinas <catalin.marinas at arm.com>
The patch adds support for THP (transparent huge pages) to LPAE
systems. When this feature is enabled, the kernel tries to map
anonymous pages as 2MB sections where possible.
Signed-off-by: Catalin Marinas <catalin.marinas at arm.com>
[steve.capper at linaro.org: symbolic constants used, value of
PMD_SECT_SPLITTING adjusted, tlbflush.h included in pgtable.h,
added PROT_NONE support.]
Signed-off-by: Steve Capper <steve.capper at linaro.org>
Reviewed-by: Will Deacon <will.deacon at arm.com>
---
arch/arm/Kconfig | 4 ++
arch/arm/include/asm/pgtable-3level-hwdef.h | 2 +
arch/arm/include/asm/pgtable-3level.h | 60 +++++++++++++++++++++++++++++
arch/arm/include/asm/pgtable.h | 3 ++
arch/arm/include/asm/tlb.h | 6 +++
arch/arm/include/asm/tlbflush.h | 2 +
arch/arm/mm/fsr-3level.c | 2 +-
7 files changed, 78 insertions(+), 1 deletion(-)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 860f034..f07a462 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1711,6 +1711,10 @@ config SYS_SUPPORTS_HUGETLBFS
def_bool y
depends on ARM_LPAE
+config HAVE_ARCH_TRANSPARENT_HUGEPAGE
+ def_bool y
+ depends on ARM_LPAE
+
source "mm/Kconfig"
config FORCE_MAX_ZONEORDER
diff --git a/arch/arm/include/asm/pgtable-3level-hwdef.h b/arch/arm/include/asm/pgtable-3level-hwdef.h
index 42df407..f088c86 100644
--- a/arch/arm/include/asm/pgtable-3level-hwdef.h
+++ b/arch/arm/include/asm/pgtable-3level-hwdef.h
@@ -42,6 +42,8 @@
*/
#define PMD_SECT_BUFFERABLE (_AT(pmdval_t, 1) << 2)
#define PMD_SECT_CACHEABLE (_AT(pmdval_t, 1) << 3)
+#define PMD_SECT_USER (_AT(pmdval_t, 1) << 6) /* AP[1] */
+#define PMD_SECT_RDONLY (_AT(pmdval_t, 1) << 7) /* AP[2] */
#define PMD_SECT_S (_AT(pmdval_t, 3) << 8)
#define PMD_SECT_AF (_AT(pmdval_t, 1) << 10)
#define PMD_SECT_nG (_AT(pmdval_t, 1) << 11)
diff --git a/arch/arm/include/asm/pgtable-3level.h b/arch/arm/include/asm/pgtable-3level.h
index d1bcd82..54733e5 100644
--- a/arch/arm/include/asm/pgtable-3level.h
+++ b/arch/arm/include/asm/pgtable-3level.h
@@ -87,6 +87,11 @@
#define L_PTE_SPECIAL (_AT(pteval_t, 1) << 56) /* unused */
#define L_PTE_NONE (_AT(pteval_t, 1) << 57) /* PROT_NONE */
+#define PMD_SECT_VALID (_AT(pmdval_t, 1) << 0)
+#define PMD_SECT_DIRTY (_AT(pmdval_t, 1) << 55)
+#define PMD_SECT_SPLITTING (_AT(pmdval_t, 1) << 56)
+#define PMD_SECT_NONE (_AT(pmdval_t, 1) << 57)
+
/*
* To be used in assembly code with the upper page attributes.
*/
@@ -196,6 +201,61 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr)
#define pte_huge(pte) (pte_val(pte) && !(pte_val(pte) & PTE_TABLE_BIT))
#define pte_mkhuge(pte) (__pte(pte_val(pte) & ~PTE_TABLE_BIT))
+#define pmd_young(pmd) (pmd_val(pmd) & PMD_SECT_AF)
+
+#define __HAVE_ARCH_PMD_WRITE
+#define pmd_write(pmd) (!(pmd_val(pmd) & PMD_SECT_RDONLY))
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+#define pmd_trans_huge(pmd) (pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT))
+#define pmd_trans_splitting(pmd) (pmd_val(pmd) & PMD_SECT_SPLITTING)
+#endif
+
+#define PMD_BIT_FUNC(fn,op) \
+static inline pmd_t pmd_##fn(pmd_t pmd) { pmd_val(pmd) op; return pmd; }
+
+PMD_BIT_FUNC(wrprotect, |= PMD_SECT_RDONLY);
+PMD_BIT_FUNC(mkold, &= ~PMD_SECT_AF);
+PMD_BIT_FUNC(mksplitting, |= PMD_SECT_SPLITTING);
+PMD_BIT_FUNC(mkwrite, &= ~PMD_SECT_RDONLY);
+PMD_BIT_FUNC(mkdirty, |= PMD_SECT_DIRTY);
+PMD_BIT_FUNC(mkyoung, |= PMD_SECT_AF);
+
+#define pmd_mkhuge(pmd) (__pmd(pmd_val(pmd) & ~PMD_TABLE_BIT))
+
+#define pmd_pfn(pmd) (((pmd_val(pmd) & PMD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
+#define pfn_pmd(pfn,prot) (__pmd(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)))
+#define mk_pmd(page,prot) pfn_pmd(page_to_pfn(page),prot)
+
+/* represent a notpresent pmd by zero, this is used by pmdp_invalidate */
+#define pmd_mknotpresent(pmd) (__pmd(0))
+
+static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
+{
+ const pmdval_t mask = PMD_SECT_USER | PMD_SECT_XN | PMD_SECT_RDONLY |
+ PMD_SECT_VALID | PMD_SECT_NONE;
+ pmd_val(pmd) = (pmd_val(pmd) & ~mask) | (pgprot_val(newprot) & mask);
+ return pmd;
+}
+
+static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
+ pmd_t *pmdp, pmd_t pmd)
+{
+ BUG_ON(addr >= TASK_SIZE);
+
+ /* create a faulting entry if PROT_NONE protected */
+ if (pmd_val(pmd) & PMD_SECT_NONE)
+ pmd_val(pmd) &= ~PMD_SECT_VALID;
+
+ *pmdp = __pmd(pmd_val(pmd) | PMD_SECT_nG);
+ flush_pmd_entry(pmdp);
+}
+
+static inline int has_transparent_hugepage(void)
+{
+ return 1;
+}
+
#endif /* __ASSEMBLY__ */
#endif /* _ASM_PGTABLE_3LEVEL_H */
diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
index 9bcd262..eaedce7 100644
--- a/arch/arm/include/asm/pgtable.h
+++ b/arch/arm/include/asm/pgtable.h
@@ -24,6 +24,9 @@
#include <asm/memory.h>
#include <asm/pgtable-hwdef.h>
+
+#include <asm/tlbflush.h>
+
#ifdef CONFIG_ARM_LPAE
#include <asm/pgtable-3level.h>
#else
diff --git a/arch/arm/include/asm/tlb.h b/arch/arm/include/asm/tlb.h
index 99a1951..bdc62da 100644
--- a/arch/arm/include/asm/tlb.h
+++ b/arch/arm/include/asm/tlb.h
@@ -223,6 +223,12 @@ static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp,
#endif
}
+static inline void
+tlb_remove_pmd_tlb_entry(struct mmu_gather *tlb, pmd_t *pmdp, unsigned long addr)
+{
+ tlb_add_flush(tlb, addr);
+}
+
#define pte_free_tlb(tlb, ptep, addr) __pte_free_tlb(tlb, ptep, addr)
#define pmd_free_tlb(tlb, pmdp, addr) __pmd_free_tlb(tlb, pmdp, addr)
#define pud_free_tlb(tlb, pudp, addr) pud_free((tlb)->mm, pudp)
diff --git a/arch/arm/include/asm/tlbflush.h b/arch/arm/include/asm/tlbflush.h
index a3625d1..c374592 100644
--- a/arch/arm/include/asm/tlbflush.h
+++ b/arch/arm/include/asm/tlbflush.h
@@ -535,6 +535,8 @@ static inline void update_mmu_cache(struct vm_area_struct *vma,
}
#endif
+#define update_mmu_cache_pmd(vma, address, pmd) do { } while (0)
+
#endif
#endif /* CONFIG_MMU */
diff --git a/arch/arm/mm/fsr-3level.c b/arch/arm/mm/fsr-3level.c
index e115fc7..ab4409a 100644
--- a/arch/arm/mm/fsr-3level.c
+++ b/arch/arm/mm/fsr-3level.c
@@ -9,7 +9,7 @@ static struct fsr_info fsr_info[] = {
{ do_page_fault, SIGSEGV, SEGV_MAPERR, "level 3 translation fault" },
{ do_bad, SIGBUS, 0, "reserved access flag fault" },
{ do_bad, SIGSEGV, SEGV_ACCERR, "level 1 access flag fault" },
- { do_bad, SIGSEGV, SEGV_ACCERR, "level 2 access flag fault" },
+ { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 access flag fault" },
{ do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 access flag fault" },
{ do_bad, SIGBUS, 0, "reserved permission fault" },
{ do_bad, SIGSEGV, SEGV_ACCERR, "level 1 permission fault" },
--
1.8.1.4
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