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464fd83e84
fixrange_init() allocates page tables for all addresses higher than FIXADDR_TOP. On processors that override the default FIXADDR_TOP address of 0xfffe_0000, this can consume up to 4 pages (1 page per 4MB) for pgd's that are never used. Signed-off-by: Kevin Cernekee <cernekee@gmail.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/1980/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
70 lines
1.7 KiB
C
70 lines
1.7 KiB
C
/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 2003 by Ralf Baechle
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*/
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#include <linux/init.h>
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#include <linux/mm.h>
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#include <linux/bootmem.h>
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#include <linux/highmem.h>
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#include <asm/fixmap.h>
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#include <asm/pgtable.h>
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#include <asm/pgalloc.h>
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void pgd_init(unsigned long page)
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{
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unsigned long *p = (unsigned long *) page;
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int i;
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for (i = 0; i < USER_PTRS_PER_PGD; i+=8) {
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p[i + 0] = (unsigned long) invalid_pte_table;
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p[i + 1] = (unsigned long) invalid_pte_table;
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p[i + 2] = (unsigned long) invalid_pte_table;
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p[i + 3] = (unsigned long) invalid_pte_table;
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p[i + 4] = (unsigned long) invalid_pte_table;
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p[i + 5] = (unsigned long) invalid_pte_table;
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p[i + 6] = (unsigned long) invalid_pte_table;
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p[i + 7] = (unsigned long) invalid_pte_table;
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}
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}
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void __init pagetable_init(void)
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{
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unsigned long vaddr;
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pgd_t *pgd_base;
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#ifdef CONFIG_HIGHMEM
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pgd_t *pgd;
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pud_t *pud;
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pmd_t *pmd;
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pte_t *pte;
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#endif
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/* Initialize the entire pgd. */
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pgd_init((unsigned long)swapper_pg_dir);
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pgd_init((unsigned long)swapper_pg_dir
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+ sizeof(pgd_t) * USER_PTRS_PER_PGD);
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pgd_base = swapper_pg_dir;
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/*
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* Fixed mappings:
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*/
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vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
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fixrange_init(vaddr, vaddr + FIXADDR_SIZE, pgd_base);
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#ifdef CONFIG_HIGHMEM
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/*
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* Permanent kmaps:
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*/
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vaddr = PKMAP_BASE;
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fixrange_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
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pgd = swapper_pg_dir + __pgd_offset(vaddr);
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pud = pud_offset(pgd, vaddr);
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pmd = pmd_offset(pud, vaddr);
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pte = pte_offset_kernel(pmd, vaddr);
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pkmap_page_table = pte;
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#endif
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}
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