cregit-Linux how code gets into the kernel

Release 4.14 arch/mn10300/mm/pgtable.c

Directory: arch/mn10300/mm
/* 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); }

Contributors

PersonTokensPropCommitsCommitProp
David Howells133100.00%2100.00%
Total133100.00%2100.00%


pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address) { pte_t *pte = (pte_t *)__get_free_page(GFP_KERNEL); if (pte) clear_page(pte); return pte; }

Contributors

PersonTokensPropCommitsCommitProp
David Howells40100.00%1100.00%
Total40100.00%1100.00%


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, 0); #else pte = alloc_pages(GFP_KERNEL, 0); #endif if (!pte) return NULL; clear_highpage(pte); if (!pgtable_page_ctor(pte)) { __free_page(pte); return NULL; } return pte; }

Contributors

PersonTokensPropCommitsCommitProp
David Howells6073.17%150.00%
Kirill A. Shutemov2226.83%150.00%
Total82100.00%2100.00%

/* * 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); }

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PersonTokensPropCommitsCommitProp
David Howells65100.00%1100.00%
Total65100.00%1100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
David Howells72100.00%1100.00%
Total72100.00%1100.00%


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)); }

Contributors

PersonTokensPropCommitsCommitProp
David Howells87100.00%1100.00%
Total87100.00%1100.00%

/* 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); }

Contributors

PersonTokensPropCommitsCommitProp
David Howells35100.00%1100.00%
Total35100.00%1100.00%


pgd_t *pgd_alloc(struct mm_struct *mm) { return quicklist_alloc(0, GFP_KERNEL, pgd_ctor); }

Contributors

PersonTokensPropCommitsCommitProp
David Howells21100.00%1100.00%
Total21100.00%1100.00%


void pgd_free(struct mm_struct *mm, pgd_t *pgd) { quicklist_free(0, pgd_dtor, pgd); }

Contributors

PersonTokensPropCommitsCommitProp
David Howells23100.00%1100.00%
Total23100.00%1100.00%


void __init pgtable_cache_init(void) { }

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PersonTokensPropCommitsCommitProp
David Howells7100.00%1100.00%
Total7100.00%1100.00%


void check_pgt_cache(void) { quicklist_trim(0, pgd_dtor, 25, 16); }

Contributors

PersonTokensPropCommitsCommitProp
David Howells18100.00%1100.00%
Total18100.00%1100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
David Howells61495.64%240.00%
Kirill A. Shutemov223.43%120.00%
Tejun Heo50.78%120.00%
Nadia Yvette Chambers10.16%120.00%
Total642100.00%5100.00%
Directory: arch/mn10300/mm
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