[RFC PATCH 5/6] ARM: mm: Transparent huge page support for LPAE systems.
Steve Capper
steve.capper at arm.com
Thu Oct 18 12:15:41 EDT 2012
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 arm.com: symbolic constants used, value of PMD_SECT_SPLITTING
adjusted, tlbflush.h included in pgtable.h]
Signed-off-by: Will Deacon <will.deacon at arm.com>
Signed-off-by: Steve Capper <steve.capper at arm.com>
---
arch/arm/Kconfig | 4 ++
arch/arm/include/asm/pgtable-2level.h | 2 +
arch/arm/include/asm/pgtable-3level-hwdef.h | 2 +
arch/arm/include/asm/pgtable-3level.h | 57 +++++++++++++++++++++++++++
arch/arm/include/asm/pgtable.h | 4 +-
arch/arm/include/asm/tlb.h | 6 +++
arch/arm/include/asm/tlbflush.h | 2 +
arch/arm/mm/fsr-3level.c | 2 +-
8 files changed, 77 insertions(+), 2 deletions(-)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index dd0a230..9621d5f 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1771,6 +1771,10 @@ config SYS_SUPPORTS_HUGETLBFS
def_bool y
depends on ARM_LPAE || (!CPU_USE_DOMAINS && !MEMORY_FAILURE)
+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-2level.h b/arch/arm/include/asm/pgtable-2level.h
index fd1d9be..34f4775 100644
--- a/arch/arm/include/asm/pgtable-2level.h
+++ b/arch/arm/include/asm/pgtable-2level.h
@@ -182,6 +182,8 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr)
/* we don't need complex calculations here as the pmd is folded into the pgd */
#define pmd_addr_end(addr,end) (end)
+#define pmd_present(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) != PMD_TYPE_FAULT)
+
#define set_pte_ext(ptep,pte,ext) cpu_set_pte_ext(ptep,pte,ext)
diff --git a/arch/arm/include/asm/pgtable-3level-hwdef.h b/arch/arm/include/asm/pgtable-3level-hwdef.h
index d795282..53c7f67 100644
--- a/arch/arm/include/asm/pgtable-3level-hwdef.h
+++ b/arch/arm/include/asm/pgtable-3level-hwdef.h
@@ -38,6 +38,8 @@
*/
#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 d086f61..31c071f 100644
--- a/arch/arm/include/asm/pgtable-3level.h
+++ b/arch/arm/include/asm/pgtable-3level.h
@@ -85,6 +85,9 @@
#define L_PTE_DIRTY (_AT(pteval_t, 1) << 55) /* unused */
#define L_PTE_SPECIAL (_AT(pteval_t, 1) << 56) /* unused */
+#define PMD_SECT_DIRTY (_AT(pmdval_t, 1) << 55)
+#define PMD_SECT_SPLITTING (_AT(pmdval_t, 1) << 57)
+
/*
* To be used in assembly code with the upper page attributes.
*/
@@ -166,6 +169,60 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr)
#define pte_mkhuge(pte) (__pte((pte_val(pte) & ~PMD_TYPE_MASK) | PMD_TYPE_SECT))
+#define pmd_present(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) != PMD_TYPE_FAULT)
+#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_TYPE_MASK) == PMD_TYPE_SECT)
+#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);
+PMD_BIT_FUNC(mknotpresent, &= ~PMD_TYPE_MASK);
+
+#define pmd_mkhuge(pmd) (__pmd((pmd_val(pmd) & ~PMD_TYPE_MASK) | PMD_TYPE_SECT))
+
+#define pmd_pfn(pmd) ((pmd_val(pmd) & 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)
+
+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_val(pmd) = (pmd_val(pmd) & ~mask) | (pgprot_val(newprot) & mask);
+ return pmd;
+}
+
+static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
+{
+ *pmdp = 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);
+ pmd = __pmd(pmd_val(pmd) | PMD_SECT_nG);
+ set_pmd(pmdp, pmd);
+ 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 c35bf46..767aa7c 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
@@ -163,7 +166,6 @@ extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
#define pgd_offset_k(addr) pgd_offset(&init_mm, addr)
#define pmd_none(pmd) (!pmd_val(pmd))
-#define pmd_present(pmd) (pmd_val(pmd))
static inline pte_t *pmd_page_vaddr(pmd_t pmd)
{
diff --git a/arch/arm/include/asm/tlb.h b/arch/arm/include/asm/tlb.h
index 685e9e87..0fc2d9d 100644
--- a/arch/arm/include/asm/tlb.h
+++ b/arch/arm/include/asm/tlb.h
@@ -229,6 +229,12 @@ 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 6e924d3..907cede 100644
--- a/arch/arm/include/asm/tlbflush.h
+++ b/arch/arm/include/asm/tlbflush.h
@@ -505,6 +505,8 @@ 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 05a4e94..47f4c6f 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" },
--
1.7.9.5
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