ARM64: mm: THP support.

Bring Transparent HugePage support to ARM. The size of a
transparent huge page depends on the normal page size. A
transparent huge page is always represented as a pmd.

If PAGE_SIZE is 4KB, THPs are 2MB.
If PAGE_SIZE is 64KB, THPs are 512MB.

Signed-off-by: Steve Capper <steve.capper@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 10607d63b945778c268c15001e96beb8d126cfa6..308a55636f76c1bde5d445d619dd52bafd20215e 100644 (file)
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -189,6 +189,9 @@ config ARCH_WANT_GENERAL_HUGETLB
 config ARCH_WANT_HUGE_PMD_SHARE
        def_bool y if !ARM64_64K_PAGES
 
+config HAVE_ARCH_TRANSPARENT_HUGEPAGE
+       def_bool y
+
 source "mm/Kconfig"
 
 config FORCE_MAX_ZONEORDER

diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h
index e6e0a0d4cf9ade5d63b2cab26c315ffbc279927d..63c9d0de05bb29c66b827297957f1fd232dfdcfe 100644 (file)
--- a/arch/arm64/include/asm/pgtable-hwdef.h
+++ b/arch/arm64/include/asm/pgtable-hwdef.h
@@ -42,6 +42,10 @@
 /*
  * Section
  */
+#define PMD_SECT_VALID         (_AT(pmdval_t, 1) << 0)
+#define PMD_SECT_PROT_NONE     (_AT(pmdval_t, 1) << 2)
+#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/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 21771330f809373f210fd48b60ab2198318ddefb..720fc4a2be494f72c840d39623ec96d2fe928c59 100644 (file)
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -187,6 +187,61 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
 
 #define __HAVE_ARCH_PTE_SPECIAL
 
+/*
+ * Software PMD bits for THP
+ */
+
+#define PMD_SECT_DIRTY         (_AT(pmdval_t, 1) << 55)
+#define PMD_SECT_SPLITTING     (_AT(pmdval_t, 1) << 57)
+
+/*
+ * THP definitions.
+ */
+#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);
+PMD_BIT_FUNC(mknotpresent, &= ~PMD_TYPE_MASK);
+
+#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)
+
+#define pmd_page(pmd)           pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK))
+
+static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
+{
+       const pmdval_t mask = PMD_SECT_USER | PMD_SECT_PXN | PMD_SECT_UXN |
+                             PMD_SECT_RDONLY | PMD_SECT_PROT_NONE |
+                             PMD_SECT_VALID;
+       pmd_val(pmd) = (pmd_val(pmd) & ~mask) | (pgprot_val(newprot) & mask);
+       return pmd;
+}
+
+#define set_pmd_at(mm, addr, pmdp, pmd)        set_pmd(pmdp, pmd)
+
+static inline int has_transparent_hugepage(void)
+{
+       return 1;
+}
+
 /*
  * Mark the prot value as uncacheable and unbufferable.
  */

diff --git a/arch/arm64/include/asm/tlb.h b/arch/arm64/include/asm/tlb.h
index 654f0968030b702f8040d07d54445c3f34174c20..46b3beb4b773c85cd381f72301b8f2e9dfdc7a97 100644 (file)
--- a/arch/arm64/include/asm/tlb.h
+++ b/arch/arm64/include/asm/tlb.h
@@ -187,4 +187,10 @@ static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp,
 
 #define tlb_migrate_finish(mm)         do { } while (0)
 
+static inline void
+tlb_remove_pmd_tlb_entry(struct mmu_gather *tlb, pmd_t *pmdp, unsigned long addr)
+{
+       tlb_add_flush(tlb, addr);
+}
+
 #endif

diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h
index 122d6320f7453d985a6eb5754a245752c7abb78c..8b482035cfc2434bdba34d3e24e6308ac01f423e 100644 (file)
--- a/arch/arm64/include/asm/tlbflush.h
+++ b/arch/arm64/include/asm/tlbflush.h
@@ -117,6 +117,8 @@ static inline void update_mmu_cache(struct vm_area_struct *vma,
        dsb();
 }
 
+#define update_mmu_cache_pmd(vma, address, pmd) do { } while (0)
+
 #endif
 
 #endif