MIPS: Transparent Huge Pages support

Signed-off-by: Ralf Baechle <[e-mail]>

arch/mips/Kconfig

···
 	select HAVE_KRETPROBES
 	select HAVE_DEBUG_KMEMLEAK
 	select ARCH_BINFMT_ELF_RANDOMIZE_PIE
+	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
 	select RTC_LIB if !MACH_LOONGSON
 	select GENERIC_ATOMIC64 if !64BIT
 	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
···
 	depends on SYS_HAS_CPU_R4X00
 	select CPU_SUPPORTS_32BIT_KERNEL
 	select CPU_SUPPORTS_64BIT_KERNEL
+	select CPU_SUPPORTS_HUGEPAGES
 	help
 	  MIPS Technologies R4000-series processors other than 4300, including
 	  the R4000, R4400, R4600, and 4700.
···
 	select CPU_HAS_PREFETCH
 	select CPU_SUPPORTS_32BIT_KERNEL
 	select CPU_SUPPORTS_64BIT_KERNEL
+	select CPU_SUPPORTS_HUGEPAGES
 
 config CPU_R5000
 	bool "R5000"
 	depends on SYS_HAS_CPU_R5000
 	select CPU_SUPPORTS_32BIT_KERNEL
 	select CPU_SUPPORTS_64BIT_KERNEL
+	select CPU_SUPPORTS_HUGEPAGES
 	help
 	  MIPS Technologies R5000-series processors other than the Nevada.
 
···
 	depends on SYS_HAS_CPU_R5432
 	select CPU_SUPPORTS_32BIT_KERNEL
 	select CPU_SUPPORTS_64BIT_KERNEL
+	select CPU_SUPPORTS_HUGEPAGES
 
 config CPU_R5500
 	bool "R5500"
···
 	depends on SYS_HAS_CPU_NEVADA
 	select CPU_SUPPORTS_32BIT_KERNEL
 	select CPU_SUPPORTS_64BIT_KERNEL
+	select CPU_SUPPORTS_HUGEPAGES
 	help
 	  QED / PMC-Sierra RM52xx-series ("Nevada") processors.
 
···
 	select CPU_SUPPORTS_32BIT_KERNEL
 	select CPU_SUPPORTS_64BIT_KERNEL
 	select CPU_SUPPORTS_HIGHMEM
+	select CPU_SUPPORTS_HUGEPAGES
 	help
 	  MIPS Technologies R10000-series processors.
 
···
 	select CPU_SUPPORTS_32BIT_KERNEL
 	select CPU_SUPPORTS_64BIT_KERNEL
 	select CPU_SUPPORTS_HIGHMEM
+	select CPU_SUPPORTS_HUGEPAGES
 
 config CPU_RM9000
 	bool "RM9000"
···
 	select CPU_SUPPORTS_32BIT_KERNEL
 	select CPU_SUPPORTS_64BIT_KERNEL
 	select CPU_SUPPORTS_HIGHMEM
+	select CPU_SUPPORTS_HUGEPAGES
 	select WEAK_ORDERING
 
 config CPU_SB1
···
 	select CPU_SUPPORTS_32BIT_KERNEL
 	select CPU_SUPPORTS_64BIT_KERNEL
 	select CPU_SUPPORTS_HIGHMEM
+	select CPU_SUPPORTS_HUGEPAGES
 	select WEAK_ORDERING
 
 config CPU_CAVIUM_OCTEON
···
 	select CPU_SUPPORTS_32BIT_KERNEL
 	select CPU_SUPPORTS_64BIT_KERNEL
 	select CPU_SUPPORTS_HIGHMEM
+	select CPU_SUPPORTS_HUGEPAGES
 	select WEAK_ORDERING
 	select WEAK_REORDERING_BEYOND_LLSC
-	select CPU_SUPPORTS_HUGEPAGES
 	help
 	  Netlogic Microsystems XLR/XLS processors.
 
···
 	select CPU_SUPPORTS_32BIT_KERNEL
 	select CPU_SUPPORTS_64BIT_KERNEL
 	select CPU_SUPPORTS_HIGHMEM
+	select CPU_SUPPORTS_HUGEPAGES
 
 config CPU_LOONGSON1
 	bool

arch/mips/include/asm/pgtable-64.h

···
 
 static inline int pmd_bad(pmd_t pmd)
 {
-#ifdef CONFIG_HUGETLB_PAGE
+#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
 	/* pmd_huge(pmd) but inline */
 	if (unlikely(pmd_val(pmd) & _PAGE_HUGE))
 		return 0;

arch/mips/include/asm/pgtable-bits.h

···
 #define _PAGE_HUGE		({BUG(); 1; })  /* Dummy value */
 #endif
 
+#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
+/* huge tlb page */
+#define _PAGE_SPLITTING_SHIFT	(_PAGE_HUGE_SHIFT + 1)
+#define _PAGE_SPLITTING		(1 << _PAGE_SPLITTING_SHIFT)
+#else
+#define _PAGE_SPLITTING_SHIFT	(_PAGE_HUGE_SHIFT)
+#define _PAGE_SPLITTING		({BUG(); 1; })  /* Dummy value */
+#endif
+
 /* Page cannot be executed */
-#define _PAGE_NO_EXEC_SHIFT	(cpu_has_rixi ? _PAGE_HUGE_SHIFT + 1 : _PAGE_HUGE_SHIFT)
+#define _PAGE_NO_EXEC_SHIFT	(cpu_has_rixi ? _PAGE_SPLITTING_SHIFT + 1 : _PAGE_SPLITTING_SHIFT)
 #define _PAGE_NO_EXEC		({BUG_ON(!cpu_has_rixi); 1 << _PAGE_NO_EXEC_SHIFT; })
 
 /* Page cannot be read */

arch/mips/include/asm/pgtable.h

···
 #ifndef _ASM_PGTABLE_H
 #define _ASM_PGTABLE_H
 
+#include <linux/mmzone.h>
 #ifdef CONFIG_32BIT
 #include <asm/pgtable-32.h>
 #endif
···
  * and a page entry and page directory to the page they refer to.
  */
 #define pmd_phys(pmd)		virt_to_phys((void *)pmd_val(pmd))
-#define pmd_page(pmd)		(pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT))
+
+#define __pmd_page(pmd)		(pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT))
+#ifndef CONFIG_TRANSPARENT_HUGEPAGE
+#define pmd_page(pmd)		__pmd_page(pmd)
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE  */
+
 #define pmd_page_vaddr(pmd)	pmd_val(pmd)
 
 #if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
···
 	__update_cache(vma, address, pte);
 }
 
+static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
+	unsigned long address, pmd_t *pmdp)
+{
+	pte_t pte = *(pte_t *)pmdp;
+
+	__update_tlb(vma, address, pte);
+}
+
 #define kern_addr_valid(addr)	(1)
 
 #ifdef CONFIG_64BIT_PHYS_ADDR
···
 #define io_remap_pfn_range(vma, vaddr, pfn, size, prot)		\
 		remap_pfn_range(vma, vaddr, pfn, size, prot)
 #endif
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+
+extern int has_transparent_hugepage(void);
+
+static inline int pmd_trans_huge(pmd_t pmd)
+{
+	return !!(pmd_val(pmd) & _PAGE_HUGE);
+}
+
+static inline pmd_t pmd_mkhuge(pmd_t pmd)
+{
+	pmd_val(pmd) |= _PAGE_HUGE;
+
+	return pmd;
+}
+
+static inline int pmd_trans_splitting(pmd_t pmd)
+{
+	return !!(pmd_val(pmd) & _PAGE_SPLITTING);
+}
+
+static inline pmd_t pmd_mksplitting(pmd_t pmd)
+{
+	pmd_val(pmd) |= _PAGE_SPLITTING;
+
+	return pmd;
+}
+
+extern void set_pmd_at(struct mm_struct *mm, unsigned long addr,
+		       pmd_t *pmdp, pmd_t pmd);
+
+#define __HAVE_ARCH_PMDP_SPLITTING_FLUSH
+/* Extern to avoid header file madness */
+extern void pmdp_splitting_flush(struct vm_area_struct *vma,
+					unsigned long address,
+					pmd_t *pmdp);
+
+#define __HAVE_ARCH_PMD_WRITE
+static inline int pmd_write(pmd_t pmd)
+{
+	return !!(pmd_val(pmd) & _PAGE_WRITE);
+}
+
+static inline pmd_t pmd_wrprotect(pmd_t pmd)
+{
+	pmd_val(pmd) &= ~(_PAGE_WRITE | _PAGE_SILENT_WRITE);
+	return pmd;
+}
+
+static inline pmd_t pmd_mkwrite(pmd_t pmd)
+{
+	pmd_val(pmd) |= _PAGE_WRITE;
+	if (pmd_val(pmd) & _PAGE_MODIFIED)
+		pmd_val(pmd) |= _PAGE_SILENT_WRITE;
+
+	return pmd;
+}
+
+static inline int pmd_dirty(pmd_t pmd)
+{
+	return !!(pmd_val(pmd) & _PAGE_MODIFIED);
+}
+
+static inline pmd_t pmd_mkclean(pmd_t pmd)
+{
+	pmd_val(pmd) &= ~(_PAGE_MODIFIED | _PAGE_SILENT_WRITE);
+	return pmd;
+}
+
+static inline pmd_t pmd_mkdirty(pmd_t pmd)
+{
+	pmd_val(pmd) |= _PAGE_MODIFIED;
+	if (pmd_val(pmd) & _PAGE_WRITE)
+		pmd_val(pmd) |= _PAGE_SILENT_WRITE;
+
+	return pmd;
+}
+
+static inline int pmd_young(pmd_t pmd)
+{
+	return !!(pmd_val(pmd) & _PAGE_ACCESSED);
+}
+
+static inline pmd_t pmd_mkold(pmd_t pmd)
+{
+	pmd_val(pmd) &= ~(_PAGE_ACCESSED|_PAGE_SILENT_READ);
+
+	return pmd;
+}
+
+static inline pmd_t pmd_mkyoung(pmd_t pmd)
+{
+	pmd_val(pmd) |= _PAGE_ACCESSED;
+
+	if (cpu_has_rixi) {
+		if (!(pmd_val(pmd) & _PAGE_NO_READ))
+			pmd_val(pmd) |= _PAGE_SILENT_READ;
+	} else {
+		if (pmd_val(pmd) & _PAGE_READ)
+			pmd_val(pmd) |= _PAGE_SILENT_READ;
+	}
+
+	return pmd;
+}
+
+/* Extern to avoid header file madness */
+extern pmd_t mk_pmd(struct page *page, pgprot_t prot);
+
+static inline unsigned long pmd_pfn(pmd_t pmd)
+{
+	return pmd_val(pmd) >> _PFN_SHIFT;
+}
+
+static inline struct page *pmd_page(pmd_t pmd)
+{
+	if (pmd_trans_huge(pmd))
+		return pfn_to_page(pmd_pfn(pmd));
+
+	return pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT);
+}
+
+static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
+{
+	pmd_val(pmd) = (pmd_val(pmd) & _PAGE_CHG_MASK) | pgprot_val(newprot);
+	return pmd;
+}
+
+static inline pmd_t pmd_mknotpresent(pmd_t pmd)
+{
+	pmd_val(pmd) &= ~(_PAGE_PRESENT | _PAGE_VALID | _PAGE_DIRTY);
+
+	return pmd;
+}
+
+/*
+ * The generic version pmdp_get_and_clear uses a version of pmd_clear() with a
+ * different prototype.
+ */
+#define __HAVE_ARCH_PMDP_GET_AND_CLEAR
+static inline pmd_t pmdp_get_and_clear(struct mm_struct *mm,
+				       unsigned long address, pmd_t *pmdp)
+{
+	pmd_t old = *pmdp;
+
+	pmd_clear(pmdp);
+
+	return old;
+}
+
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
 #include <asm-generic/pgtable.h>
 

arch/mips/kernel/mips_ksyms.c

···
 #include <linux/interrupt.h>
 #include <linux/export.h>
 #include <asm/checksum.h>
-#include <asm/pgtable.h>
+#include <linux/mm.h>
 #include <asm/uaccess.h>
 #include <asm/ftrace.h>
 

arch/mips/mm/pgtable-64.c

···
 #include <asm/fixmap.h>
 #include <asm/pgtable.h>
 #include <asm/pgalloc.h>
+#include <asm/tlbflush.h>
 
 void pgd_init(unsigned long page)
 {
···
 	} while (p != end);
 }
 #endif
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+
+void pmdp_splitting_flush(struct vm_area_struct *vma,
+			 unsigned long address,
+			 pmd_t *pmdp)
+{
+	if (!pmd_trans_splitting(*pmdp)) {
+		pmd_t pmd = pmd_mksplitting(*pmdp);
+		set_pmd_at(vma->vm_mm, address, pmdp, pmd);
+	}
+}
+
+#endif
+
+pmd_t mk_pmd(struct page *page, pgprot_t prot)
+{
+	pmd_t pmd;
+
+	pmd_val(pmd) = (page_to_pfn(page) << _PFN_SHIFT) | pgprot_val(prot);
+
+	return pmd;
+}
+
+void set_pmd_at(struct mm_struct *mm, unsigned long addr,
+		pmd_t *pmdp, pmd_t pmd)
+{
+	*pmdp = pmd;
+	flush_tlb_all();
+}
 
 void __init pagetable_init(void)
 {

arch/mips/mm/tlb-r4k.c

···
 	EXIT_CRITICAL(flags);
 }
 
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+
+int __init has_transparent_hugepage(void)
+{
+	unsigned int mask;
+	unsigned long flags;
+
+	ENTER_CRITICAL(flags);
+	write_c0_pagemask(PM_HUGE_MASK);
+	back_to_back_c0_hazard();
+	mask = read_c0_pagemask();
+	write_c0_pagemask(PM_DEFAULT_MASK);
+
+	EXIT_CRITICAL(flags);
+
+	return mask == PM_HUGE_MASK;
+}
+
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE  */
+
 static int __cpuinitdata ntlb;
 static int __init set_ntlb(char *str)
 {

arch/mips/mm/tlbex.c

···
 	pr_define("_PAGE_WRITE_SHIFT %d\n", _PAGE_WRITE_SHIFT);
 	pr_define("_PAGE_ACCESSED_SHIFT %d\n", _PAGE_ACCESSED_SHIFT);
 	pr_define("_PAGE_MODIFIED_SHIFT %d\n", _PAGE_MODIFIED_SHIFT);
-#ifdef _PAGE_HUGE_SHIFT
+#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
 	pr_define("_PAGE_HUGE_SHIFT %d\n", _PAGE_HUGE_SHIFT);
+	pr_define("_PAGE_SPLITTING_SHIFT %d\n", _PAGE_SPLITTING_SHIFT);
 #endif
 	if (cpu_has_rixi) {
 #ifdef _PAGE_NO_EXEC_SHIFT