a1f242ff46
This adds ioremap_prot and pte_pgprot() so that one can extract protection bits from a PTE and use them to ioremap_prot() (in order to support ptrace of VM_IO | VM_PFNMAP as per Rik's patch). This moves a couple of flag checks around in the ioremap implementations of arch/powerpc. There's a side effect of allowing non-cacheable and non-guarded mappings on ppc32 which before would always have _PAGE_GUARDED set whenever _PAGE_NO_CACHE is. (standard ioremap will still set _PAGE_GUARDED, but ioremap_prot will be capable of setting such a non guarded mapping). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Rik van Riel <riel@redhat.com> Cc: Dave Airlie <airlied@linux.ie> Cc: Hugh Dickins <hugh@veritas.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
250 lines
6 KiB
C
250 lines
6 KiB
C
/*
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* This file contains ioremap and related functions for 64-bit machines.
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*
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* Derived from arch/ppc64/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@samba.org)
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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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* Dave Engebretsen <engebret@us.ibm.com>
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* Rework for PPC64 port.
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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/signal.h>
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/string.h>
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#include <linux/types.h>
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#include <linux/mman.h>
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#include <linux/mm.h>
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#include <linux/swap.h>
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#include <linux/stddef.h>
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#include <linux/vmalloc.h>
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#include <linux/init.h>
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#include <asm/pgalloc.h>
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#include <asm/page.h>
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#include <asm/prom.h>
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#include <asm/io.h>
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#include <asm/mmu_context.h>
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#include <asm/pgtable.h>
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#include <asm/mmu.h>
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#include <asm/smp.h>
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#include <asm/machdep.h>
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#include <asm/tlb.h>
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#include <asm/processor.h>
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#include <asm/cputable.h>
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#include <asm/sections.h>
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#include <asm/system.h>
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#include <asm/abs_addr.h>
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#include <asm/firmware.h>
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#include "mmu_decl.h"
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unsigned long ioremap_bot = IOREMAP_BASE;
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/*
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* map_io_page currently only called by __ioremap
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* map_io_page adds an entry to the ioremap page table
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* and adds an entry to the HPT, possibly bolting it
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*/
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static int map_io_page(unsigned long ea, unsigned long pa, int flags)
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{
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pgd_t *pgdp;
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pud_t *pudp;
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pmd_t *pmdp;
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pte_t *ptep;
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if (mem_init_done) {
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pgdp = pgd_offset_k(ea);
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pudp = pud_alloc(&init_mm, pgdp, ea);
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if (!pudp)
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return -ENOMEM;
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pmdp = pmd_alloc(&init_mm, pudp, ea);
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if (!pmdp)
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return -ENOMEM;
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ptep = pte_alloc_kernel(pmdp, ea);
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if (!ptep)
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return -ENOMEM;
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set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT,
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__pgprot(flags)));
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} else {
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/*
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* If the mm subsystem is not fully up, we cannot create a
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* linux page table entry for this mapping. Simply bolt an
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* entry in the hardware page table.
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*
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*/
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if (htab_bolt_mapping(ea, ea + PAGE_SIZE, pa, flags,
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mmu_io_psize, mmu_kernel_ssize)) {
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printk(KERN_ERR "Failed to do bolted mapping IO "
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"memory at %016lx !\n", pa);
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return -ENOMEM;
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}
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}
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return 0;
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}
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/**
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* __ioremap_at - Low level function to establish the page tables
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* for an IO mapping
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*/
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void __iomem * __ioremap_at(phys_addr_t pa, void *ea, unsigned long size,
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unsigned long flags)
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{
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unsigned long i;
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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 |= pgprot_val(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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/* We don't support the 4K PFN hack with ioremap */
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if (flags & _PAGE_4K_PFN)
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return NULL;
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WARN_ON(pa & ~PAGE_MASK);
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WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
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WARN_ON(size & ~PAGE_MASK);
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for (i = 0; i < size; i += PAGE_SIZE)
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if (map_io_page((unsigned long)ea+i, pa+i, flags))
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return NULL;
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return (void __iomem *)ea;
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}
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/**
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* __iounmap_from - Low level function to tear down the page tables
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* for an IO mapping. This is used for mappings that
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* are manipulated manually, like partial unmapping of
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* PCI IOs or ISA space.
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*/
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void __iounmap_at(void *ea, unsigned long size)
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{
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WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
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WARN_ON(size & ~PAGE_MASK);
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unmap_kernel_range((unsigned long)ea, size);
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}
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void __iomem * __ioremap(phys_addr_t addr, unsigned long size,
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unsigned long flags)
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{
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phys_addr_t paligned;
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void __iomem *ret;
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/*
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* Choose an address to map it to.
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* Once the imalloc system is running, we use it.
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* Before that, we map using addresses going
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* up from ioremap_bot. imalloc will use
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* the addresses from ioremap_bot through
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* IMALLOC_END
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*
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*/
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paligned = addr & PAGE_MASK;
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size = PAGE_ALIGN(addr + size) - paligned;
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if ((size == 0) || (paligned == 0))
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return NULL;
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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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ioremap_bot, IOREMAP_END);
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if (area == NULL)
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return NULL;
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ret = __ioremap_at(paligned, area->addr, size, flags);
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if (!ret)
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vunmap(area->addr);
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} else {
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ret = __ioremap_at(paligned, (void *)ioremap_bot, size, flags);
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if (ret)
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ioremap_bot += size;
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}
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if (ret)
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ret += addr & ~PAGE_MASK;
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return ret;
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}
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void __iomem * ioremap(phys_addr_t addr, unsigned long size)
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{
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unsigned long flags = _PAGE_NO_CACHE | _PAGE_GUARDED;
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if (ppc_md.ioremap)
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return ppc_md.ioremap(addr, size, flags);
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return __ioremap(addr, size, flags);
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}
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void __iomem * ioremap_flags(phys_addr_t addr, unsigned long size,
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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;
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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);
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if (ppc_md.ioremap)
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return ppc_md.ioremap(addr, size, flags);
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return __ioremap(addr, size, flags);
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}
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/*
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* Unmap an IO region and remove it from imalloc'd list.
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* Access to IO memory should be serialized by driver.
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*/
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void __iounmap(volatile void __iomem *token)
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{
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void *addr;
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if (!mem_init_done)
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return;
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addr = (void *) ((unsigned long __force)
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PCI_FIX_ADDR(token) & PAGE_MASK);
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if ((unsigned long)addr < ioremap_bot) {
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printk(KERN_WARNING "Attempt to iounmap early bolted mapping"
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" at 0x%p\n", addr);
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return;
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}
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vunmap(addr);
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}
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void iounmap(volatile void __iomem *token)
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{
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if (ppc_md.iounmap)
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ppc_md.iounmap(token);
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else
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__iounmap(token);
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}
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EXPORT_SYMBOL(ioremap);
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EXPORT_SYMBOL(ioremap_flags);
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EXPORT_SYMBOL(__ioremap);
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EXPORT_SYMBOL(__ioremap_at);
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EXPORT_SYMBOL(iounmap);
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EXPORT_SYMBOL(__iounmap);
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EXPORT_SYMBOL(__iounmap_at);
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