PPC44x supports page sizes other than 4K however when 64K page sizes
are selected compilation fails. This is due to a change in the
definition of pgtable_t introduced by the following patch:
commit 5c1f6ee9a3
Author: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
powerpc: Reduce PTE table memory wastage
The above patch only implements the new layout for PPC64 so it doesn't
compile for PPC32 with a 64K page size. Ideally we should implement
the same layout for PPC32 however for the meantime this patch reverts
the definition of pgtable_t for PPC32.
Signed-off-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
		
	
			
		
			
				
	
	
		
			415 lines
		
	
	
	
		
			12 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			415 lines
		
	
	
	
		
			12 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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#ifndef __ASSEMBLY__
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#include <linux/types.h>
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#else
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#include <asm/types.h>
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#endif
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#include <asm/asm-compat.h>
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#include <asm/kdump.h>
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/*
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 * On regular PPC32 page size is 4K (but we support 4K/16K/64K/256K pages
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 * on PPC44x). 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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#if defined(CONFIG_PPC_256K_PAGES)
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#define PAGE_SHIFT		18
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#elif defined(CONFIG_PPC_64K_PAGES)
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#define PAGE_SHIFT		16
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#elif defined(CONFIG_PPC_16K_PAGES)
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#define PAGE_SHIFT		14
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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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#ifndef __ASSEMBLY__
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#ifdef CONFIG_HUGETLB_PAGE
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extern unsigned int HPAGE_SHIFT;
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#else
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#define HPAGE_SHIFT PAGE_SHIFT
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#endif
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#define HPAGE_SIZE		((1UL) << HPAGE_SHIFT)
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#define HPAGE_MASK		(~(HPAGE_SIZE - 1))
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#define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
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#define HUGE_MAX_HSTATE		(MMU_PAGE_COUNT-1)
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#endif
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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 ways 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_NONSTATIC_KERNEL)
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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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#ifdef CONFIG_RELOCATABLE_PPC32
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extern long long virt_phys_offset;
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#endif
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#endif /* __ASSEMBLY__ */
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#define PHYSICAL_START	kernstart_addr
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#else	/* !CONFIG_NONSTATIC_KERNEL */
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#define PHYSICAL_START	ASM_CONST(CONFIG_PHYSICAL_START)
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#endif
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/* See Description below for VIRT_PHYS_OFFSET */
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#ifdef CONFIG_RELOCATABLE_PPC32
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#define VIRT_PHYS_OFFSET virt_phys_offset
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#else
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#define VIRT_PHYS_OFFSET (KERNELBASE - PHYSICAL_START)
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#endif
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#ifdef CONFIG_PPC64
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#define MEMORY_START	0UL
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#elif defined(CONFIG_NONSTATIC_KERNEL)
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#define MEMORY_START	memstart_addr
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#else
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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		((unsigned long)(MEMORY_START >> PAGE_SHIFT))
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#define pfn_valid(pfn)		((pfn) >= ARCH_PFN_OFFSET && (pfn) < 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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/*
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 * On Book-E parts we need __va to parse the device tree and we can't
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 * determine MEMORY_START until then.  However we can determine PHYSICAL_START
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 * from information at hand (program counter, TLB lookup).
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 *
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 * On BookE with RELOCATABLE (RELOCATABLE_PPC32)
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 *
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 *   With RELOCATABLE_PPC32,  we support loading the kernel at any physical 
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 *   address without any restriction on the page alignment.
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 *
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 *   We find the runtime address of _stext and relocate ourselves based on 
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 *   the following calculation:
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 *
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 *  	  virtual_base = ALIGN_DOWN(KERNELBASE,256M) +
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 *  				MODULO(_stext.run,256M)
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 *   and create the following mapping:
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 *
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 * 	  ALIGN_DOWN(_stext.run,256M) => ALIGN_DOWN(KERNELBASE,256M)
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 *
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 *   When we process relocations, we cannot depend on the
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 *   existing equation for the __va()/__pa() translations:
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 *
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 * 	   __va(x) = (x)  - PHYSICAL_START + KERNELBASE
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 *
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 *   Where:
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 *   	 PHYSICAL_START = kernstart_addr = Physical address of _stext
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 *  	 KERNELBASE = Compiled virtual address of _stext.
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 *
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 *   This formula holds true iff, kernel load address is TLB page aligned.
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 *
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 *   In our case, we need to also account for the shift in the kernel Virtual 
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 *   address.
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 *
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 *   E.g.,
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 *
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 *   Let the kernel be loaded at 64MB and KERNELBASE be 0xc0000000 (same as PAGE_OFFSET).
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 *   In this case, we would be mapping 0 to 0xc0000000, and kernstart_addr = 64M
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 *
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 *   Now __va(1MB) = (0x100000) - (0x4000000) + 0xc0000000
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 *                 = 0xbc100000 , which is wrong.
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 *
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 *   Rather, it should be : 0xc0000000 + 0x100000 = 0xc0100000
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 *      	according to our mapping.
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 *
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 *   Hence we use the following formula to get the translations right:
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 *
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 * 	  __va(x) = (x) - [ PHYSICAL_START - Effective KERNELBASE ]
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 *
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 * 	  Where :
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 * 		PHYSICAL_START = dynamic load address.(kernstart_addr variable)
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 * 		Effective KERNELBASE = virtual_base =
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 * 				     = ALIGN_DOWN(KERNELBASE,256M) +
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 * 						MODULO(PHYSICAL_START,256M)
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 *
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 * 	To make the cost of __va() / __pa() more light weight, we introduce
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 * 	a new variable virt_phys_offset, which will hold :
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 *
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 * 	virt_phys_offset = Effective KERNELBASE - PHYSICAL_START
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 * 			 = ALIGN_DOWN(KERNELBASE,256M) - 
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 * 			 	ALIGN_DOWN(PHYSICALSTART,256M)
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 *
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 * 	Hence :
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 *
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 * 	__va(x) = x - PHYSICAL_START + Effective KERNELBASE
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 * 		= x + virt_phys_offset
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 *
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 * 		and
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 * 	__pa(x) = x + PHYSICAL_START - Effective KERNELBASE
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 * 		= x - virt_phys_offset
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 * 		
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 * On non-Book-E PPC64 PAGE_OFFSET and MEMORY_START are constants so use
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 * the other definitions for __va & __pa.
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 */
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#ifdef CONFIG_BOOKE
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#define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + VIRT_PHYS_OFFSET))
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#define __pa(x) ((unsigned long)(x) - VIRT_PHYS_OFFSET)
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#else
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#ifdef CONFIG_PPC64
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/*
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 * gcc miscompiles (unsigned long)(&static_var) - PAGE_OFFSET
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 * with -mcmodel=medium, so we use & and | instead of - and + on 64-bit.
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 */
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#define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) | PAGE_OFFSET))
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#define __pa(x) ((unsigned long)(x) & 0x0fffffffffffffffUL)
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#else /* 32-bit, non book E */
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#define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + PAGE_OFFSET - MEMORY_START))
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#define __pa(x) ((unsigned long)(x) - PAGE_OFFSET + MEMORY_START)
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#endif
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#endif
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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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/*
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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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#ifdef CONFIG_PPC_BOOK3E_64
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#define is_kernel_addr(x)	((x) >= 0x8000000000000000ul)
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#else
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#define is_kernel_addr(x)	((x) >= PAGE_OFFSET)
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#endif
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#ifndef CONFIG_PPC_BOOK3S_64
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/*
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 * Use the top bit of the higher-level page table entries to indicate whether
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 * the entries we point to contain hugepages.  This works because we know that
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 * the page tables live in kernel space.  If we ever decide to support having
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 * page tables at arbitrary addresses, this breaks and will have to change.
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 */
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#ifdef CONFIG_PPC64
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#define PD_HUGE 0x8000000000000000
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#else
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#define PD_HUGE 0x80000000
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#endif
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#endif /* CONFIG_PPC_BOOK3S_64 */
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/*
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 * Some number of bits at the level of the page table that points to
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 * a hugepte are used to encode the size.  This masks those bits.
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 */
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#define HUGEPD_SHIFT_MASK     0x3f
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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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#if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_PPC_STD_MMU_64)
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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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#if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_PPC_STD_MMU_64)
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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 pte_t 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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typedef struct { signed long pd; } hugepd_t;
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#ifdef CONFIG_HUGETLB_PAGE
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#ifdef CONFIG_PPC_BOOK3S_64
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static inline int hugepd_ok(hugepd_t hpd)
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{
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	/*
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	 * hugepd pointer, bottom two bits == 00 and next 4 bits
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	 * indicate size of table
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	 */
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	return (((hpd.pd & 0x3) == 0x0) && ((hpd.pd & HUGEPD_SHIFT_MASK) != 0));
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}
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#else
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static inline int hugepd_ok(hugepd_t hpd)
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{
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	return (hpd.pd > 0);
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}
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#endif
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#define is_hugepd(pdep)               (hugepd_ok(*((hugepd_t *)(pdep))))
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int pgd_huge(pgd_t pgd);
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#else /* CONFIG_HUGETLB_PAGE */
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#define is_hugepd(pdep)			0
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#define pgd_huge(pgd)			0
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#endif /* CONFIG_HUGETLB_PAGE */
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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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extern int devmem_is_allowed(unsigned long pfn);
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#ifdef CONFIG_PPC_SMLPAR
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void arch_free_page(struct page *page, int order);
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#define HAVE_ARCH_FREE_PAGE
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#endif
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struct vm_area_struct;
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#if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_PPC64)
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typedef pte_t *pgtable_t;
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#else
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						|
typedef struct page *pgtable_t;
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#endif
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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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