423 строки
9.7 KiB
C
423 строки
9.7 KiB
C
/*
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* This file contains the routines setting up the linux page tables.
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* -- paulus
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*
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* Derived from arch/ppc/mm/init.c:
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* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
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*
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* Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
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* and Cort Dougan (PReP) (cort@cs.nmt.edu)
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* Copyright (C) 1996 Paul Mackerras
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*
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* Derived from "arch/i386/mm/init.c"
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* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/mm.h>
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#include <linux/vmalloc.h>
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#include <linux/init.h>
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#include <linux/highmem.h>
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#include <asm/pgtable.h>
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#include <asm/pgalloc.h>
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#include <asm/fixmap.h>
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#include <asm/io.h>
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#include "mmu_decl.h"
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unsigned long ioremap_base;
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unsigned long ioremap_bot;
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EXPORT_SYMBOL(ioremap_bot); /* aka VMALLOC_END */
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#if defined(CONFIG_6xx) || defined(CONFIG_POWER3)
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#define HAVE_BATS 1
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#endif
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#if defined(CONFIG_FSL_BOOKE)
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#define HAVE_TLBCAM 1
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#endif
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extern char etext[], _stext[];
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#ifdef CONFIG_SMP
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extern void hash_page_sync(void);
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#endif
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#ifdef HAVE_BATS
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extern phys_addr_t v_mapped_by_bats(unsigned long va);
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extern unsigned long p_mapped_by_bats(phys_addr_t pa);
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void setbat(int index, unsigned long virt, phys_addr_t phys,
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unsigned int size, int flags);
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#else /* !HAVE_BATS */
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#define v_mapped_by_bats(x) (0UL)
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#define p_mapped_by_bats(x) (0UL)
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#endif /* HAVE_BATS */
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#ifdef HAVE_TLBCAM
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extern unsigned int tlbcam_index;
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extern unsigned long v_mapped_by_tlbcam(unsigned long va);
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extern unsigned long p_mapped_by_tlbcam(unsigned long pa);
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#else /* !HAVE_TLBCAM */
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#define v_mapped_by_tlbcam(x) (0UL)
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#define p_mapped_by_tlbcam(x) (0UL)
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#endif /* HAVE_TLBCAM */
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#ifdef CONFIG_PTE_64BIT
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/* Some processors use an 8kB pgdir because they have 8-byte Linux PTEs. */
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#define PGDIR_ORDER 1
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#else
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#define PGDIR_ORDER 0
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#endif
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pgd_t *pgd_alloc(struct mm_struct *mm)
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{
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pgd_t *ret;
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ret = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, PGDIR_ORDER);
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return ret;
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}
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void pgd_free(struct mm_struct *mm, pgd_t *pgd)
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{
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free_pages((unsigned long)pgd, PGDIR_ORDER);
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}
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__init_refok pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
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{
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pte_t *pte;
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extern int mem_init_done;
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extern void *early_get_page(void);
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if (mem_init_done) {
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pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
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} else {
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pte = (pte_t *)early_get_page();
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if (pte)
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clear_page(pte);
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}
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return pte;
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}
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pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address)
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{
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struct page *ptepage;
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#ifdef CONFIG_HIGHPTE
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gfp_t flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_REPEAT | __GFP_ZERO;
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#else
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gfp_t flags = GFP_KERNEL | __GFP_REPEAT | __GFP_ZERO;
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#endif
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ptepage = alloc_pages(flags, 0);
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if (!ptepage)
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return NULL;
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pgtable_page_ctor(ptepage);
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return ptepage;
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}
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void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
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{
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#ifdef CONFIG_SMP
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hash_page_sync();
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#endif
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free_page((unsigned long)pte);
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}
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void pte_free(struct mm_struct *mm, pgtable_t ptepage)
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{
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#ifdef CONFIG_SMP
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hash_page_sync();
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#endif
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pgtable_page_dtor(ptepage);
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__free_page(ptepage);
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}
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void __iomem *
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ioremap(phys_addr_t addr, unsigned long size)
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{
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return __ioremap(addr, size, _PAGE_NO_CACHE | _PAGE_GUARDED);
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}
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EXPORT_SYMBOL(ioremap);
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void __iomem *
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ioremap_flags(phys_addr_t addr, unsigned long size, unsigned long flags)
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{
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/* writeable implies dirty for kernel addresses */
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if (flags & _PAGE_RW)
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flags |= _PAGE_DIRTY | _PAGE_HWWRITE;
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/* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */
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flags &= ~(_PAGE_USER | _PAGE_EXEC | _PAGE_HWEXEC);
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return __ioremap(addr, size, flags);
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}
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EXPORT_SYMBOL(ioremap_flags);
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void __iomem *
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__ioremap(phys_addr_t addr, unsigned long size, unsigned long flags)
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{
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unsigned long v, i;
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phys_addr_t p;
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int err;
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/* Make sure we have the base flags */
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if ((flags & _PAGE_PRESENT) == 0)
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flags |= _PAGE_KERNEL;
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/* Non-cacheable page cannot be coherent */
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if (flags & _PAGE_NO_CACHE)
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flags &= ~_PAGE_COHERENT;
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/*
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* Choose an address to map it to.
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* Once the vmalloc system is running, we use it.
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* Before then, we use space going down from ioremap_base
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* (ioremap_bot records where we're up to).
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*/
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p = addr & PAGE_MASK;
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size = PAGE_ALIGN(addr + size) - p;
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/*
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* If the address lies within the first 16 MB, assume it's in ISA
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* memory space
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*/
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if (p < 16*1024*1024)
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p += _ISA_MEM_BASE;
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/*
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* Don't allow anybody to remap normal RAM that we're using.
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* mem_init() sets high_memory so only do the check after that.
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*/
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if (mem_init_done && (p < virt_to_phys(high_memory))) {
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printk("__ioremap(): phys addr 0x%llx is RAM lr %p\n",
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(unsigned long long)p, __builtin_return_address(0));
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return NULL;
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}
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if (size == 0)
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return NULL;
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/*
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* Is it already mapped? Perhaps overlapped by a previous
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* BAT mapping. If the whole area is mapped then we're done,
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* otherwise remap it since we want to keep the virt addrs for
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* each request contiguous.
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*
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* We make the assumption here that if the bottom and top
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* of the range we want are mapped then it's mapped to the
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* same virt address (and this is contiguous).
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* -- Cort
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*/
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if ((v = p_mapped_by_bats(p)) /*&& p_mapped_by_bats(p+size-1)*/ )
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goto out;
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if ((v = p_mapped_by_tlbcam(p)))
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goto out;
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if (mem_init_done) {
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struct vm_struct *area;
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area = get_vm_area(size, VM_IOREMAP);
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if (area == 0)
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return NULL;
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v = (unsigned long) area->addr;
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} else {
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v = (ioremap_bot -= size);
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}
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/*
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* Should check if it is a candidate for a BAT mapping
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*/
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err = 0;
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for (i = 0; i < size && err == 0; i += PAGE_SIZE)
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err = map_page(v+i, p+i, flags);
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if (err) {
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if (mem_init_done)
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vunmap((void *)v);
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return NULL;
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}
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out:
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return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK));
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}
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EXPORT_SYMBOL(__ioremap);
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void iounmap(volatile void __iomem *addr)
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{
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/*
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* If mapped by BATs then there is nothing to do.
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* Calling vfree() generates a benign warning.
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*/
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if (v_mapped_by_bats((unsigned long)addr)) return;
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if (addr > high_memory && (unsigned long) addr < ioremap_bot)
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vunmap((void *) (PAGE_MASK & (unsigned long)addr));
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}
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EXPORT_SYMBOL(iounmap);
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int map_page(unsigned long va, phys_addr_t pa, int flags)
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{
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pmd_t *pd;
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pte_t *pg;
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int err = -ENOMEM;
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/* Use upper 10 bits of VA to index the first level map */
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pd = pmd_offset(pud_offset(pgd_offset_k(va), va), va);
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/* Use middle 10 bits of VA to index the second-level map */
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pg = pte_alloc_kernel(pd, va);
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if (pg != 0) {
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err = 0;
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/* The PTE should never be already set nor present in the
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* hash table
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*/
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BUG_ON(pte_val(*pg) & (_PAGE_PRESENT | _PAGE_HASHPTE));
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set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT,
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__pgprot(flags)));
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}
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return err;
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}
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/*
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* Map in a big chunk of physical memory starting at KERNELBASE.
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*/
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void __init mapin_ram(void)
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{
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unsigned long v, s, f;
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phys_addr_t p;
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int ktext;
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s = mmu_mapin_ram();
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v = KERNELBASE + s;
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p = memstart_addr + s;
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for (; s < total_lowmem; s += PAGE_SIZE) {
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ktext = ((char *) v >= _stext && (char *) v < etext);
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f = ktext ?_PAGE_RAM_TEXT : _PAGE_RAM;
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map_page(v, p, f);
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#ifdef CONFIG_PPC_STD_MMU_32
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if (ktext)
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hash_preload(&init_mm, v, 0, 0x300);
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#endif
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v += PAGE_SIZE;
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p += PAGE_SIZE;
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}
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}
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/* Scan the real Linux page tables and return a PTE pointer for
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* a virtual address in a context.
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* Returns true (1) if PTE was found, zero otherwise. The pointer to
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* the PTE pointer is unmodified if PTE is not found.
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*/
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int
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get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep, pmd_t **pmdp)
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{
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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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int retval = 0;
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pgd = pgd_offset(mm, addr & PAGE_MASK);
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if (pgd) {
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pud = pud_offset(pgd, addr & PAGE_MASK);
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if (pud && pud_present(*pud)) {
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pmd = pmd_offset(pud, addr & PAGE_MASK);
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if (pmd_present(*pmd)) {
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pte = pte_offset_map(pmd, addr & PAGE_MASK);
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if (pte) {
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retval = 1;
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*ptep = pte;
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if (pmdp)
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*pmdp = pmd;
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/* XXX caller needs to do pte_unmap, yuck */
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}
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}
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}
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}
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return(retval);
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}
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#ifdef CONFIG_DEBUG_PAGEALLOC
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static int __change_page_attr(struct page *page, pgprot_t prot)
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{
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pte_t *kpte;
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pmd_t *kpmd;
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unsigned long address;
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BUG_ON(PageHighMem(page));
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address = (unsigned long)page_address(page);
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if (v_mapped_by_bats(address) || v_mapped_by_tlbcam(address))
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return 0;
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if (!get_pteptr(&init_mm, address, &kpte, &kpmd))
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return -EINVAL;
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set_pte_at(&init_mm, address, kpte, mk_pte(page, prot));
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wmb();
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flush_HPTE(0, address, pmd_val(*kpmd));
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pte_unmap(kpte);
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return 0;
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}
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/*
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* Change the page attributes of an page in the linear mapping.
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*
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* THIS CONFLICTS WITH BAT MAPPINGS, DEBUG USE ONLY
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*/
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static int change_page_attr(struct page *page, int numpages, pgprot_t prot)
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{
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int i, err = 0;
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unsigned long flags;
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local_irq_save(flags);
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for (i = 0; i < numpages; i++, page++) {
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err = __change_page_attr(page, prot);
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if (err)
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break;
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}
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local_irq_restore(flags);
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return err;
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}
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void kernel_map_pages(struct page *page, int numpages, int enable)
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{
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if (PageHighMem(page))
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return;
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change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0));
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}
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#endif /* CONFIG_DEBUG_PAGEALLOC */
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static int fixmaps;
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unsigned long FIXADDR_TOP = 0xfffff000;
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EXPORT_SYMBOL(FIXADDR_TOP);
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void __set_fixmap (enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags)
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{
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unsigned long address = __fix_to_virt(idx);
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if (idx >= __end_of_fixed_addresses) {
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BUG();
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return;
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}
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map_page(address, phys, pgprot_val(flags));
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fixmaps++;
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}
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void __this_fixmap_does_not_exist(void)
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{
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WARN_ON(1);
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}
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