David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 1 | /* MN10300 Page table management |
| 2 | * |
| 3 | * Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd. |
| 4 | * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. |
| 5 | * Modified by David Howells (dhowells@redhat.com) |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or |
| 8 | * modify it under the terms of the GNU General Public Licence |
| 9 | * as published by the Free Software Foundation; either version |
| 10 | * 2 of the Licence, or (at your option) any later version. |
| 11 | */ |
| 12 | #include <linux/sched.h> |
| 13 | #include <linux/kernel.h> |
| 14 | #include <linux/errno.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame^] | 15 | #include <linux/gfp.h> |
David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 16 | #include <linux/mm.h> |
| 17 | #include <linux/swap.h> |
| 18 | #include <linux/smp.h> |
| 19 | #include <linux/highmem.h> |
David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 20 | #include <linux/pagemap.h> |
| 21 | #include <linux/spinlock.h> |
| 22 | #include <linux/quicklist.h> |
| 23 | |
| 24 | #include <asm/system.h> |
| 25 | #include <asm/pgtable.h> |
| 26 | #include <asm/pgalloc.h> |
| 27 | #include <asm/tlb.h> |
| 28 | #include <asm/tlbflush.h> |
| 29 | |
David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 30 | /* |
| 31 | * Associate a large virtual page frame with a given physical page frame |
| 32 | * and protection flags for that frame. pfn is for the base of the page, |
| 33 | * vaddr is what the page gets mapped to - both must be properly aligned. |
| 34 | * The pmd must already be instantiated. Assumes PAE mode. |
| 35 | */ |
| 36 | void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags) |
| 37 | { |
| 38 | pgd_t *pgd; |
| 39 | pud_t *pud; |
| 40 | pmd_t *pmd; |
| 41 | |
| 42 | if (vaddr & (PMD_SIZE-1)) { /* vaddr is misaligned */ |
| 43 | printk(KERN_ERR "set_pmd_pfn: vaddr misaligned\n"); |
| 44 | return; /* BUG(); */ |
| 45 | } |
| 46 | if (pfn & (PTRS_PER_PTE-1)) { /* pfn is misaligned */ |
| 47 | printk(KERN_ERR "set_pmd_pfn: pfn misaligned\n"); |
| 48 | return; /* BUG(); */ |
| 49 | } |
| 50 | pgd = swapper_pg_dir + pgd_index(vaddr); |
| 51 | if (pgd_none(*pgd)) { |
| 52 | printk(KERN_ERR "set_pmd_pfn: pgd_none\n"); |
| 53 | return; /* BUG(); */ |
| 54 | } |
| 55 | pud = pud_offset(pgd, vaddr); |
| 56 | pmd = pmd_offset(pud, vaddr); |
| 57 | set_pmd(pmd, pfn_pmd(pfn, flags)); |
| 58 | /* |
| 59 | * It's enough to flush this one mapping. |
| 60 | * (PGE mappings get flushed as well) |
| 61 | */ |
| 62 | __flush_tlb_one(vaddr); |
| 63 | } |
| 64 | |
| 65 | pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address) |
| 66 | { |
| 67 | pte_t *pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT); |
| 68 | if (pte) |
| 69 | clear_page(pte); |
| 70 | return pte; |
| 71 | } |
| 72 | |
| 73 | struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address) |
| 74 | { |
| 75 | struct page *pte; |
| 76 | |
| 77 | #ifdef CONFIG_HIGHPTE |
| 78 | pte = alloc_pages(GFP_KERNEL|__GFP_HIGHMEM|__GFP_REPEAT, 0); |
| 79 | #else |
| 80 | pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT, 0); |
| 81 | #endif |
| 82 | if (pte) |
| 83 | clear_highpage(pte); |
| 84 | return pte; |
| 85 | } |
| 86 | |
| 87 | /* |
| 88 | * List of all pgd's needed for non-PAE so it can invalidate entries |
| 89 | * in both cached and uncached pgd's; not needed for PAE since the |
| 90 | * kernel pmd is shared. If PAE were not to share the pmd a similar |
| 91 | * tactic would be needed. This is essentially codepath-based locking |
| 92 | * against pageattr.c; it is the unique case in which a valid change |
| 93 | * of kernel pagetables can't be lazily synchronized by vmalloc faults. |
| 94 | * vmalloc faults work because attached pagetables are never freed. |
| 95 | * If the locking proves to be non-performant, a ticketing scheme with |
| 96 | * checks at dup_mmap(), exec(), and other mmlist addition points |
| 97 | * could be used. The locking scheme was chosen on the basis of |
| 98 | * manfred's recommendations and having no core impact whatsoever. |
| 99 | * -- wli |
| 100 | */ |
| 101 | DEFINE_SPINLOCK(pgd_lock); |
| 102 | struct page *pgd_list; |
| 103 | |
| 104 | static inline void pgd_list_add(pgd_t *pgd) |
| 105 | { |
| 106 | struct page *page = virt_to_page(pgd); |
| 107 | page->index = (unsigned long) pgd_list; |
| 108 | if (pgd_list) |
| 109 | set_page_private(pgd_list, (unsigned long) &page->index); |
| 110 | pgd_list = page; |
| 111 | set_page_private(page, (unsigned long) &pgd_list); |
| 112 | } |
| 113 | |
| 114 | static inline void pgd_list_del(pgd_t *pgd) |
| 115 | { |
| 116 | struct page *next, **pprev, *page = virt_to_page(pgd); |
| 117 | next = (struct page *) page->index; |
| 118 | pprev = (struct page **) page_private(page); |
| 119 | *pprev = next; |
| 120 | if (next) |
| 121 | set_page_private(next, (unsigned long) pprev); |
| 122 | } |
| 123 | |
| 124 | void pgd_ctor(void *pgd) |
| 125 | { |
| 126 | unsigned long flags; |
| 127 | |
| 128 | if (PTRS_PER_PMD == 1) |
| 129 | spin_lock_irqsave(&pgd_lock, flags); |
| 130 | |
| 131 | memcpy((pgd_t *)pgd + USER_PTRS_PER_PGD, |
| 132 | swapper_pg_dir + USER_PTRS_PER_PGD, |
| 133 | (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t)); |
| 134 | |
| 135 | if (PTRS_PER_PMD > 1) |
| 136 | return; |
| 137 | |
| 138 | pgd_list_add(pgd); |
| 139 | spin_unlock_irqrestore(&pgd_lock, flags); |
| 140 | memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t)); |
| 141 | } |
| 142 | |
| 143 | /* never called when PTRS_PER_PMD > 1 */ |
| 144 | void pgd_dtor(void *pgd) |
| 145 | { |
| 146 | unsigned long flags; /* can be called from interrupt context */ |
| 147 | |
| 148 | spin_lock_irqsave(&pgd_lock, flags); |
| 149 | pgd_list_del(pgd); |
| 150 | spin_unlock_irqrestore(&pgd_lock, flags); |
| 151 | } |
| 152 | |
| 153 | pgd_t *pgd_alloc(struct mm_struct *mm) |
| 154 | { |
| 155 | return quicklist_alloc(0, GFP_KERNEL, pgd_ctor); |
| 156 | } |
| 157 | |
| 158 | void pgd_free(struct mm_struct *mm, pgd_t *pgd) |
| 159 | { |
| 160 | quicklist_free(0, pgd_dtor, pgd); |
| 161 | } |
| 162 | |
| 163 | void __init pgtable_cache_init(void) |
| 164 | { |
| 165 | } |
| 166 | |
| 167 | void check_pgt_cache(void) |
| 168 | { |
| 169 | quicklist_trim(0, pgd_dtor, 25, 16); |
| 170 | } |