diff options
Diffstat (limited to 'arch/mn10300/mm/pgtable.c')
| -rw-r--r-- | arch/mn10300/mm/pgtable.c | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/arch/mn10300/mm/pgtable.c b/arch/mn10300/mm/pgtable.c new file mode 100644 index 000000000..e77a7c728 --- /dev/null +++ b/arch/mn10300/mm/pgtable.c @@ -0,0 +1,174 @@ +/* MN10300 Page table management + * + * Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd. + * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. + * Modified by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ +#include <linux/sched.h> +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/gfp.h> +#include <linux/mm.h> +#include <linux/swap.h> +#include <linux/smp.h> +#include <linux/highmem.h> +#include <linux/pagemap.h> +#include <linux/spinlock.h> +#include <linux/quicklist.h> + +#include <asm/pgtable.h> +#include <asm/pgalloc.h> +#include <asm/tlb.h> +#include <asm/tlbflush.h> + +/* + * Associate a large virtual page frame with a given physical page frame + * and protection flags for that frame. pfn is for the base of the page, + * vaddr is what the page gets mapped to - both must be properly aligned. + * The pmd must already be instantiated. Assumes PAE mode. + */ +void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags) +{ + pgd_t *pgd; + pud_t *pud; + pmd_t *pmd; + + if (vaddr & (PMD_SIZE-1)) { /* vaddr is misaligned */ + printk(KERN_ERR "set_pmd_pfn: vaddr misaligned\n"); + return; /* BUG(); */ + } + if (pfn & (PTRS_PER_PTE-1)) { /* pfn is misaligned */ + printk(KERN_ERR "set_pmd_pfn: pfn misaligned\n"); + return; /* BUG(); */ + } + pgd = swapper_pg_dir + pgd_index(vaddr); + if (pgd_none(*pgd)) { + printk(KERN_ERR "set_pmd_pfn: pgd_none\n"); + return; /* BUG(); */ + } + pud = pud_offset(pgd, vaddr); + pmd = pmd_offset(pud, vaddr); + set_pmd(pmd, pfn_pmd(pfn, flags)); + /* + * It's enough to flush this one mapping. + * (PGE mappings get flushed as well) + */ + local_flush_tlb_one(vaddr); +} + +pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address) +{ + pte_t *pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT); + if (pte) + clear_page(pte); + return pte; +} + +struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address) +{ + struct page *pte; + +#ifdef CONFIG_HIGHPTE + pte = alloc_pages(GFP_KERNEL|__GFP_HIGHMEM|__GFP_REPEAT, 0); +#else + pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT, 0); +#endif + if (!pte) + return NULL; + clear_highpage(pte); + if (!pgtable_page_ctor(pte)) { + __free_page(pte); + return NULL; + } + return pte; +} + +/* + * List of all pgd's needed for non-PAE so it can invalidate entries + * in both cached and uncached pgd's; not needed for PAE since the + * kernel pmd is shared. If PAE were not to share the pmd a similar + * tactic would be needed. This is essentially codepath-based locking + * against pageattr.c; it is the unique case in which a valid change + * of kernel pagetables can't be lazily synchronized by vmalloc faults. + * vmalloc faults work because attached pagetables are never freed. + * If the locking proves to be non-performant, a ticketing scheme with + * checks at dup_mmap(), exec(), and other mmlist addition points + * could be used. The locking scheme was chosen on the basis of + * manfred's recommendations and having no core impact whatsoever. + * -- nyc + */ +DEFINE_SPINLOCK(pgd_lock); +struct page *pgd_list; + +static inline void pgd_list_add(pgd_t *pgd) +{ + struct page *page = virt_to_page(pgd); + page->index = (unsigned long) pgd_list; + if (pgd_list) + set_page_private(pgd_list, (unsigned long) &page->index); + pgd_list = page; + set_page_private(page, (unsigned long) &pgd_list); +} + +static inline void pgd_list_del(pgd_t *pgd) +{ + struct page *next, **pprev, *page = virt_to_page(pgd); + next = (struct page *) page->index; + pprev = (struct page **) page_private(page); + *pprev = next; + if (next) + set_page_private(next, (unsigned long) pprev); +} + +void pgd_ctor(void *pgd) +{ + unsigned long flags; + + if (PTRS_PER_PMD == 1) + spin_lock_irqsave(&pgd_lock, flags); + + memcpy((pgd_t *)pgd + USER_PTRS_PER_PGD, + swapper_pg_dir + USER_PTRS_PER_PGD, + (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t)); + + if (PTRS_PER_PMD > 1) + return; + + pgd_list_add(pgd); + spin_unlock_irqrestore(&pgd_lock, flags); + memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t)); +} + +/* never called when PTRS_PER_PMD > 1 */ +void pgd_dtor(void *pgd) +{ + unsigned long flags; /* can be called from interrupt context */ + + spin_lock_irqsave(&pgd_lock, flags); + pgd_list_del(pgd); + spin_unlock_irqrestore(&pgd_lock, flags); +} + +pgd_t *pgd_alloc(struct mm_struct *mm) +{ + return quicklist_alloc(0, GFP_KERNEL, pgd_ctor); +} + +void pgd_free(struct mm_struct *mm, pgd_t *pgd) +{ + quicklist_free(0, pgd_dtor, pgd); +} + +void __init pgtable_cache_init(void) +{ +} + +void check_pgt_cache(void) +{ + quicklist_trim(0, pgd_dtor, 25, 16); +} |