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37dd2badcf
Added support to allow an 85xx kernel to be run from a non-zero physical address (useful for cooperative asymmetric multiprocessing situations and kdump). The support can be configured at compile time by setting CONFIG_PAGE_OFFSET, CONFIG_KERNEL_START, and CONFIG_PHYSICAL_START as desired. Alternatively, the kernel build can set CONFIG_RELOCATABLE. Setting this config option causes the kernel to determine at runtime the physical addresses of CONFIG_PAGE_OFFSET and CONFIG_KERNEL_START. If CONFIG_RELOCATABLE is set, then CONFIG_PHYSICAL_START has no meaning. However, CONFIG_PHYSICAL_START will always be used to set the LOAD program header physical address field in the resulting ELF image. Currently we are limited to running at a physical address that is a multiple of 256M. This is due to how we map TLBs to cover lowmem. This should be fixed to allow 64M or maybe even 16M alignment in the future. It is considered an error to try and run a kernel at a non-aligned physical address. All the magic for this support is accomplished by proper initialization of the kernel memory subsystem and use of ARCH_PFN_OFFSET. The use of ARCH_PFN_OFFSET only affects normal memory and not IO mappings. ioremap uses map_page and isn't affected by ARCH_PFN_OFFSET. /dev/mem continues to allow access to any physical address in the system regardless of how CONFIG_PHYSICAL_START is set. Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
229 lines
6.5 KiB
C
229 lines
6.5 KiB
C
#ifndef _ASM_POWERPC_PAGE_H
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#define _ASM_POWERPC_PAGE_H
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/*
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* Copyright (C) 2001,2005 IBM Corporation.
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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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#include <asm/asm-compat.h>
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#include <asm/kdump.h>
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#include <asm/types.h>
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/*
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* On PPC32 page size is 4K. For PPC64 we support either 4K or 64K software
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* page size. When using 64K pages however, whether we are really supporting
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* 64K pages in HW or not is irrelevant to those definitions.
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*/
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#ifdef CONFIG_PPC_64K_PAGES
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#define PAGE_SHIFT 16
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#else
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#define PAGE_SHIFT 12
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#endif
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#define PAGE_SIZE (ASM_CONST(1) << PAGE_SHIFT)
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/* We do define AT_SYSINFO_EHDR but don't use the gate mechanism */
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#define __HAVE_ARCH_GATE_AREA 1
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/*
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* Subtle: (1 << PAGE_SHIFT) is an int, not an unsigned long. So if we
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* assign PAGE_MASK to a larger type it gets extended the way we want
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* (i.e. with 1s in the high bits)
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*/
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#define PAGE_MASK (~((1 << PAGE_SHIFT) - 1))
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/*
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* KERNELBASE is the virtual address of the start of the kernel, it's often
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* the same as PAGE_OFFSET, but _might not be_.
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*
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* The kdump dump kernel is one example where KERNELBASE != PAGE_OFFSET.
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*
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* PAGE_OFFSET is the virtual address of the start of lowmem.
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*
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* PHYSICAL_START is the physical address of the start of the kernel.
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*
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* MEMORY_START is the physical address of the start of lowmem.
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*
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* KERNELBASE, PAGE_OFFSET, and PHYSICAL_START are all configurable on
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* ppc32 and based on how they are set we determine MEMORY_START.
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*
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* For the linear mapping the following equation should be true:
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* KERNELBASE - PAGE_OFFSET = PHYSICAL_START - MEMORY_START
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*
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* Also, KERNELBASE >= PAGE_OFFSET and PHYSICAL_START >= MEMORY_START
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*
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* There are two was to determine a physical address from a virtual one:
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* va = pa + PAGE_OFFSET - MEMORY_START
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* va = pa + KERNELBASE - PHYSICAL_START
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*
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* If you want to know something's offset from the start of the kernel you
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* should subtract KERNELBASE.
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*
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* If you want to test if something's a kernel address, use is_kernel_addr().
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*/
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#define KERNELBASE ASM_CONST(CONFIG_KERNEL_START)
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#define PAGE_OFFSET ASM_CONST(CONFIG_PAGE_OFFSET)
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#define LOAD_OFFSET ASM_CONST((CONFIG_KERNEL_START-CONFIG_PHYSICAL_START))
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#if defined(CONFIG_RELOCATABLE) && defined(CONFIG_FLATMEM)
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#ifndef __ASSEMBLY__
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extern phys_addr_t memstart_addr;
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extern phys_addr_t kernstart_addr;
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#endif
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#define PHYSICAL_START kernstart_addr
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#define MEMORY_START memstart_addr
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#else
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#define PHYSICAL_START ASM_CONST(CONFIG_PHYSICAL_START)
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#define MEMORY_START (PHYSICAL_START + PAGE_OFFSET - KERNELBASE)
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#endif
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#ifdef CONFIG_FLATMEM
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#define ARCH_PFN_OFFSET (MEMORY_START >> PAGE_SHIFT)
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#define pfn_valid(pfn) ((pfn) >= ARCH_PFN_OFFSET && (pfn) < (ARCH_PFN_OFFSET + max_mapnr))
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#endif
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#define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
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#define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT)
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#define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
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#define __va(x) ((void *)((unsigned long)(x) - PHYSICAL_START + KERNELBASE))
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#define __pa(x) ((unsigned long)(x) + PHYSICAL_START - KERNELBASE)
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/*
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* Unfortunately the PLT is in the BSS in the PPC32 ELF ABI,
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* and needs to be executable. This means the whole heap ends
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* up being executable.
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*/
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#define VM_DATA_DEFAULT_FLAGS32 (VM_READ | VM_WRITE | VM_EXEC | \
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VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
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#define VM_DATA_DEFAULT_FLAGS64 (VM_READ | VM_WRITE | \
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VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
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#ifdef __powerpc64__
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#include <asm/page_64.h>
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#else
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#include <asm/page_32.h>
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#endif
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/* align addr on a size boundary - adjust address up/down if needed */
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#define _ALIGN_UP(addr,size) (((addr)+((size)-1))&(~((size)-1)))
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#define _ALIGN_DOWN(addr,size) ((addr)&(~((size)-1)))
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/* align addr on a size boundary - adjust address up if needed */
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#define _ALIGN(addr,size) _ALIGN_UP(addr,size)
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/* to align the pointer to the (next) page boundary */
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#define PAGE_ALIGN(addr) _ALIGN(addr, PAGE_SIZE)
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/*
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* Don't compare things with KERNELBASE or PAGE_OFFSET to test for
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* "kernelness", use is_kernel_addr() - it should do what you want.
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*/
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#define is_kernel_addr(x) ((x) >= PAGE_OFFSET)
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#ifndef __ASSEMBLY__
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#undef STRICT_MM_TYPECHECKS
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#ifdef STRICT_MM_TYPECHECKS
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/* These are used to make use of C type-checking. */
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/* PTE level */
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typedef struct { pte_basic_t pte; } pte_t;
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#define pte_val(x) ((x).pte)
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#define __pte(x) ((pte_t) { (x) })
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/* 64k pages additionally define a bigger "real PTE" type that gathers
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* the "second half" part of the PTE for pseudo 64k pages
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*/
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#ifdef CONFIG_PPC_64K_PAGES
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typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
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#else
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typedef struct { pte_t pte; } real_pte_t;
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#endif
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/* PMD level */
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#ifdef CONFIG_PPC64
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typedef struct { unsigned long pmd; } pmd_t;
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#define pmd_val(x) ((x).pmd)
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#define __pmd(x) ((pmd_t) { (x) })
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/* PUD level exusts only on 4k pages */
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#ifndef CONFIG_PPC_64K_PAGES
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typedef struct { unsigned long pud; } pud_t;
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#define pud_val(x) ((x).pud)
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#define __pud(x) ((pud_t) { (x) })
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#endif /* !CONFIG_PPC_64K_PAGES */
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#endif /* CONFIG_PPC64 */
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/* PGD level */
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typedef struct { unsigned long pgd; } pgd_t;
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#define pgd_val(x) ((x).pgd)
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#define __pgd(x) ((pgd_t) { (x) })
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/* Page protection bits */
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typedef struct { unsigned long pgprot; } pgprot_t;
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#define pgprot_val(x) ((x).pgprot)
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#define __pgprot(x) ((pgprot_t) { (x) })
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#else
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/*
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* .. while these make it easier on the compiler
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*/
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typedef pte_basic_t pte_t;
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#define pte_val(x) (x)
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#define __pte(x) (x)
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#ifdef CONFIG_PPC_64K_PAGES
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typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
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#else
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typedef unsigned long real_pte_t;
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#endif
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#ifdef CONFIG_PPC64
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typedef unsigned long pmd_t;
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#define pmd_val(x) (x)
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#define __pmd(x) (x)
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#ifndef CONFIG_PPC_64K_PAGES
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typedef unsigned long pud_t;
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#define pud_val(x) (x)
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#define __pud(x) (x)
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#endif /* !CONFIG_PPC_64K_PAGES */
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#endif /* CONFIG_PPC64 */
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typedef unsigned long pgd_t;
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#define pgd_val(x) (x)
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#define pgprot_val(x) (x)
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typedef unsigned long pgprot_t;
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#define __pgd(x) (x)
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#define __pgprot(x) (x)
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#endif
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struct page;
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extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg);
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extern void copy_user_page(void *to, void *from, unsigned long vaddr,
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struct page *p);
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extern int page_is_ram(unsigned long pfn);
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struct vm_area_struct;
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typedef struct page *pgtable_t;
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#include <asm-generic/memory_model.h>
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#endif /* __ASSEMBLY__ */
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#endif /* _ASM_POWERPC_PAGE_H */
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