From 5d9b4b19f118abfb75e352841f7bf74580d7e427 Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Sun, 13 Dec 2009 14:38:50 +0000 Subject: [PATCH] sh: Definitions for 3-level page table layout If using 64-bit PTEs and 4K pages then each page table has 512 entries (as opposed to 1024 entries with 32-bit PTEs). Unlike MIPS, SH follows the convention that all structures in the page table (pgd_t, pmd_t, pgprot_t, etc) must be the same size. Therefore, 64-bit PTEs require 64-bit PGD entries, etc. Using 2-levels of page tables and 64-bit PTEs it is only possible to map 1GB of virtual address space. In order to map all 4GB of virtual address space we need to adopt a 3-level page table layout. This actually works out better for CONFIG_SUPERH32 because we only waste 2 PGD entries on the P1 and P2 areas (which are untranslated) instead of 256. Signed-off-by: Matt Fleming Signed-off-by: Paul Mundt --- arch/sh/include/asm/pgalloc.h | 4 +++ arch/sh/include/asm/pgalloc_pmd.h | 41 +++++++++++++++++++++++ arch/sh/include/asm/pgtable.h | 4 +++ arch/sh/include/asm/pgtable_pmd.h | 55 +++++++++++++++++++++++++++++++ arch/sh/mm/Kconfig | 24 ++++++++++++-- arch/sh/mm/fault_32.c | 3 ++ arch/sh/mm/init.c | 6 ++++ 7 files changed, 134 insertions(+), 3 deletions(-) create mode 100644 arch/sh/include/asm/pgalloc_pmd.h create mode 100644 arch/sh/include/asm/pgtable_pmd.h diff --git a/arch/sh/include/asm/pgalloc.h b/arch/sh/include/asm/pgalloc.h index fe9f037ac5fd..4ea27855c3b5 100644 --- a/arch/sh/include/asm/pgalloc.h +++ b/arch/sh/include/asm/pgalloc.h @@ -6,7 +6,11 @@ #define QUICK_PT 1 /* Other page table pages that are zero on free */ +#ifdef CONFIG_PGTABLE_LEVELS_3 +#include +#else #include +#endif static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd, pte_t *pte) diff --git a/arch/sh/include/asm/pgalloc_pmd.h b/arch/sh/include/asm/pgalloc_pmd.h new file mode 100644 index 000000000000..20f75cc4eb09 --- /dev/null +++ b/arch/sh/include/asm/pgalloc_pmd.h @@ -0,0 +1,41 @@ +#ifndef __ASM_SH_PGALLOC_PMD_H +#define __ASM_SH_PGALLOC_PMD_H + +static inline pgd_t *pgd_alloc(struct mm_struct *mm) +{ + pgd_t *pgd; + int i; + + pgd = kzalloc(sizeof(*pgd) * PTRS_PER_PGD, GFP_KERNEL | __GFP_REPEAT); + + for (i = USER_PTRS_PER_PGD; i < PTRS_PER_PGD; i++) + pgd[i] = swapper_pg_dir[i]; + + return pgd; +} + +static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd) +{ + kfree(pgd); +} + +static inline void __check_pgt_cache(void) +{ +} + +static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd) +{ + set_pud(pud, __pud((unsigned long)pmd)); +} + +static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address) +{ + return quicklist_alloc(QUICK_PT, GFP_KERNEL | __GFP_REPEAT, NULL); +} + +static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd) +{ + quicklist_free(QUICK_PT, NULL, pmd); +} + +#endif /* __ASM_SH_PGALLOC_PMD_H */ diff --git a/arch/sh/include/asm/pgtable.h b/arch/sh/include/asm/pgtable.h index 9a0f66c1134c..9effcc3b0d10 100644 --- a/arch/sh/include/asm/pgtable.h +++ b/arch/sh/include/asm/pgtable.h @@ -12,7 +12,11 @@ #ifndef __ASM_SH_PGTABLE_H #define __ASM_SH_PGTABLE_H +#ifdef CONFIG_PGTABLE_LEVELS_3 +#include +#else #include +#endif #include #ifndef __ASSEMBLY__ diff --git a/arch/sh/include/asm/pgtable_pmd.h b/arch/sh/include/asm/pgtable_pmd.h new file mode 100644 index 000000000000..78dc36e1c2dd --- /dev/null +++ b/arch/sh/include/asm/pgtable_pmd.h @@ -0,0 +1,55 @@ +#ifndef __ASM_SH_PGTABLE_PMD_H +#define __ASM_SH_PGTABLE_PMD_H + +#include + +/* + * Some cores need a 3-level page table layout, for example when using + * 64-bit PTEs and 4K pages. + */ + +#define PTE_MAGNITUDE 3 /* 64-bit PTEs on extended mode SH-X2 TLB */ + +/* PGD bits */ +#define PGDIR_SHIFT 30 + +#define PTRS_PER_PGD 4 +#define USER_PTRS_PER_PGD 2 + +/* PMD bits */ +#define PMD_SHIFT (PAGE_SHIFT + (PAGE_SHIFT - 3)) +#define PMD_SIZE (1UL << PMD_SHIFT) +#define PMD_MASK (~(PMD_SIZE-1)) + +#define PTRS_PER_PMD (PAGE_SIZE / sizeof(pmd_t)) + +#define pmd_ERROR(e) \ + printk("%s:%d: bad pmd %016llx.\n", __FILE__, __LINE__, pmd_val(e)) + +typedef struct { unsigned long long pmd; } pmd_t; +#define pmd_val(x) ((x).pmd) +#define __pmd(x) ((pmd_t) { (x) } ) + +static inline unsigned long pud_page_vaddr(pud_t pud) +{ + return pud_val(pud); +} + +#define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1)) +static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address) +{ + return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address); +} + +#define pud_none(x) (!pud_val(x)) +#define pud_present(x) (pud_val(x)) +#define pud_clear(xp) do { set_pud(xp, __pud(0)); } while (0) +#define pud_bad(x) (pud_val(x) & ~PAGE_MASK) + +/* + * (puds are folded into pgds so this doesn't get actually called, + * but the define is needed for a generic inline function.) + */ +#define set_pud(pudptr, pudval) do { *(pudptr) = (pudval); } while(0) + +#endif /* __ASM_SH_PGTABLE_PMD_H */ diff --git a/arch/sh/mm/Kconfig b/arch/sh/mm/Kconfig index 0e7ba8e891cf..b3f6c1a30b22 100644 --- a/arch/sh/mm/Kconfig +++ b/arch/sh/mm/Kconfig @@ -189,6 +189,24 @@ config ARCH_MEMORY_PROBE def_bool y depends on MEMORY_HOTPLUG +choice + prompt "Page table layout" + default PGTABLE_LEVELS_3 if X2TLB + default PGTABLE_LEVELS_2 + +config PGTABLE_LEVELS_2 + bool "2 Levels" + help + This is the default page table layout for all SuperH CPUs. + +config PGTABLE_LEVELS_3 + bool "3 Levels" + depends on X2TLB + help + This enables a 3 level page table structure. + +endchoice + choice prompt "Kernel page size" default PAGE_SIZE_8KB if X2TLB @@ -196,13 +214,13 @@ choice config PAGE_SIZE_4KB bool "4kB" - depends on !MMU || !X2TLB + depends on !MMU || !X2TLB || PGTABLE_LEVELS_3 help This is the default page size used by all SuperH CPUs. config PAGE_SIZE_8KB bool "8kB" - depends on !MMU || X2TLB + depends on !MMU || X2TLB && !PGTABLE_LEVELS_3 help This enables 8kB pages as supported by SH-X2 and later MMUs. @@ -214,7 +232,7 @@ config PAGE_SIZE_16KB config PAGE_SIZE_64KB bool "64kB" - depends on !MMU || CPU_SH4 || CPU_SH5 + depends on !MMU || CPU_SH4 && !PGTABLE_LEVELS_3 || CPU_SH5 help This enables support for 64kB pages, possible on all SH-4 CPUs and later. diff --git a/arch/sh/mm/fault_32.c b/arch/sh/mm/fault_32.c index 47530104e0ad..28e22839c665 100644 --- a/arch/sh/mm/fault_32.c +++ b/arch/sh/mm/fault_32.c @@ -53,6 +53,9 @@ static inline pmd_t *vmalloc_sync_one(pgd_t *pgd, unsigned long address) if (!pud_present(*pud_k)) return NULL; + if (!pud_present(*pud)) + set_pud(pud, *pud_k); + pmd = pmd_offset(pud, address); pmd_k = pmd_offset(pud_k, address); if (!pmd_present(*pmd_k)) diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c index 432acd07e76a..761910d142f8 100644 --- a/arch/sh/mm/init.c +++ b/arch/sh/mm/init.c @@ -120,7 +120,13 @@ void __init page_table_range_init(unsigned long start, unsigned long end, for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) { pud = (pud_t *)pgd; for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) { +#ifdef __PAGETABLE_PMD_FOLDED pmd = (pmd_t *)pud; +#else + pmd = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE); + pud_populate(&init_mm, pud, pmd); + pmd += k; +#endif for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) { if (pmd_none(*pmd)) { pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);