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linux/arch/powerpc/include/asm/page.h

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#ifndef _ASM_POWERPC_PAGE_H
#define _ASM_POWERPC_PAGE_H
/*
* Copyright (C) 2001,2005 IBM Corporation.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#ifndef __ASSEMBLY__
#include <linux/types.h>
#else
#include <asm/types.h>
#endif
#include <asm/asm-compat.h>
#include <asm/kdump.h>
/*
* On regular PPC32 page size is 4K (but we support 4K/16K/64K/256K pages
* on PPC44x). For PPC64 we support either 4K or 64K software
* page size. When using 64K pages however, whether we are really supporting
* 64K pages in HW or not is irrelevant to those definitions.
*/
#if defined(CONFIG_PPC_256K_PAGES)
#define PAGE_SHIFT 18
#elif defined(CONFIG_PPC_64K_PAGES)
#define PAGE_SHIFT 16
#elif defined(CONFIG_PPC_16K_PAGES)
#define PAGE_SHIFT 14
#else
#define PAGE_SHIFT 12
#endif
#define PAGE_SIZE (ASM_CONST(1) << PAGE_SHIFT)
#ifndef __ASSEMBLY__
#ifdef CONFIG_HUGETLB_PAGE
extern unsigned int HPAGE_SHIFT;
#else
#define HPAGE_SHIFT PAGE_SHIFT
#endif
#define HPAGE_SIZE ((1UL) << HPAGE_SHIFT)
#define HPAGE_MASK (~(HPAGE_SIZE - 1))
#define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT)
#define HUGE_MAX_HSTATE (MMU_PAGE_COUNT-1)
#endif
/* We do define AT_SYSINFO_EHDR but don't use the gate mechanism */
#define __HAVE_ARCH_GATE_AREA 1
/*
* Subtle: (1 << PAGE_SHIFT) is an int, not an unsigned long. So if we
* assign PAGE_MASK to a larger type it gets extended the way we want
* (i.e. with 1s in the high bits)
*/
#define PAGE_MASK (~((1 << PAGE_SHIFT) - 1))
/*
* KERNELBASE is the virtual address of the start of the kernel, it's often
* the same as PAGE_OFFSET, but _might not be_.
*
* The kdump dump kernel is one example where KERNELBASE != PAGE_OFFSET.
*
* PAGE_OFFSET is the virtual address of the start of lowmem.
*
* PHYSICAL_START is the physical address of the start of the kernel.
*
* MEMORY_START is the physical address of the start of lowmem.
*
* KERNELBASE, PAGE_OFFSET, and PHYSICAL_START are all configurable on
* ppc32 and based on how they are set we determine MEMORY_START.
*
* For the linear mapping the following equation should be true:
* KERNELBASE - PAGE_OFFSET = PHYSICAL_START - MEMORY_START
*
* Also, KERNELBASE >= PAGE_OFFSET and PHYSICAL_START >= MEMORY_START
*
* There are two was to determine a physical address from a virtual one:
* va = pa + PAGE_OFFSET - MEMORY_START
* va = pa + KERNELBASE - PHYSICAL_START
*
* If you want to know something's offset from the start of the kernel you
* should subtract KERNELBASE.
*
* If you want to test if something's a kernel address, use is_kernel_addr().
*/
#define KERNELBASE ASM_CONST(CONFIG_KERNEL_START)
#define PAGE_OFFSET ASM_CONST(CONFIG_PAGE_OFFSET)
#define LOAD_OFFSET ASM_CONST((CONFIG_KERNEL_START-CONFIG_PHYSICAL_START))
#if defined(CONFIG_NONSTATIC_KERNEL)
#ifndef __ASSEMBLY__
extern phys_addr_t memstart_addr;
extern phys_addr_t kernstart_addr;
#ifdef CONFIG_RELOCATABLE_PPC32
extern long long virt_phys_offset;
#endif
#endif /* __ASSEMBLY__ */
#define PHYSICAL_START kernstart_addr
#else /* !CONFIG_NONSTATIC_KERNEL */
#define PHYSICAL_START ASM_CONST(CONFIG_PHYSICAL_START)
#endif
/* See Description below for VIRT_PHYS_OFFSET */
#ifdef CONFIG_RELOCATABLE_PPC32
#define VIRT_PHYS_OFFSET virt_phys_offset
#else
#define VIRT_PHYS_OFFSET (KERNELBASE - PHYSICAL_START)
#endif
#ifdef CONFIG_PPC64
#define MEMORY_START 0UL
#elif defined(CONFIG_NONSTATIC_KERNEL)
#define MEMORY_START memstart_addr
#else
#define MEMORY_START (PHYSICAL_START + PAGE_OFFSET - KERNELBASE)
#endif
#ifdef CONFIG_FLATMEM
#define ARCH_PFN_OFFSET ((unsigned long)(MEMORY_START >> PAGE_SHIFT))
#define pfn_valid(pfn) ((pfn) >= ARCH_PFN_OFFSET && (pfn) < max_mapnr)
#endif
#define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
#define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT)
#define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
/*
* On Book-E parts we need __va to parse the device tree and we can't
* determine MEMORY_START until then. However we can determine PHYSICAL_START
* from information at hand (program counter, TLB lookup).
*
* On BookE with RELOCATABLE (RELOCATABLE_PPC32)
*
* With RELOCATABLE_PPC32, we support loading the kernel at any physical
* address without any restriction on the page alignment.
*
* We find the runtime address of _stext and relocate ourselves based on
* the following calculation:
*
* virtual_base = ALIGN_DOWN(KERNELBASE,256M) +
* MODULO(_stext.run,256M)
* and create the following mapping:
*
* ALIGN_DOWN(_stext.run,256M) => ALIGN_DOWN(KERNELBASE,256M)
*
* When we process relocations, we cannot depend on the
* existing equation for the __va()/__pa() translations:
*
* __va(x) = (x) - PHYSICAL_START + KERNELBASE
*
* Where:
* PHYSICAL_START = kernstart_addr = Physical address of _stext
* KERNELBASE = Compiled virtual address of _stext.
*
* This formula holds true iff, kernel load address is TLB page aligned.
*
* In our case, we need to also account for the shift in the kernel Virtual
* address.
*
* E.g.,
*
* Let the kernel be loaded at 64MB and KERNELBASE be 0xc0000000 (same as PAGE_OFFSET).
* In this case, we would be mapping 0 to 0xc0000000, and kernstart_addr = 64M
*
* Now __va(1MB) = (0x100000) - (0x4000000) + 0xc0000000
* = 0xbc100000 , which is wrong.
*
* Rather, it should be : 0xc0000000 + 0x100000 = 0xc0100000
* according to our mapping.
*
* Hence we use the following formula to get the translations right:
*
* __va(x) = (x) - [ PHYSICAL_START - Effective KERNELBASE ]
*
* Where :
* PHYSICAL_START = dynamic load address.(kernstart_addr variable)
* Effective KERNELBASE = virtual_base =
* = ALIGN_DOWN(KERNELBASE,256M) +
* MODULO(PHYSICAL_START,256M)
*
* To make the cost of __va() / __pa() more light weight, we introduce
* a new variable virt_phys_offset, which will hold :
*
* virt_phys_offset = Effective KERNELBASE - PHYSICAL_START
* = ALIGN_DOWN(KERNELBASE,256M) -
* ALIGN_DOWN(PHYSICALSTART,256M)
*
* Hence :
*
* __va(x) = x - PHYSICAL_START + Effective KERNELBASE
* = x + virt_phys_offset
*
* and
* __pa(x) = x + PHYSICAL_START - Effective KERNELBASE
* = x - virt_phys_offset
*
* On non-Book-E PPC64 PAGE_OFFSET and MEMORY_START are constants so use
* the other definitions for __va & __pa.
*/
#ifdef CONFIG_BOOKE
#define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + VIRT_PHYS_OFFSET))
#define __pa(x) ((unsigned long)(x) - VIRT_PHYS_OFFSET)
#else
#define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + PAGE_OFFSET - MEMORY_START))
#define __pa(x) ((unsigned long)(x) - PAGE_OFFSET + MEMORY_START)
#endif
/*
* Unfortunately the PLT is in the BSS in the PPC32 ELF ABI,
* and needs to be executable. This means the whole heap ends
* up being executable.
*/
#define VM_DATA_DEFAULT_FLAGS32 (VM_READ | VM_WRITE | VM_EXEC | \
VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
#define VM_DATA_DEFAULT_FLAGS64 (VM_READ | VM_WRITE | \
VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
#ifdef __powerpc64__
#include <asm/page_64.h>
#else
#include <asm/page_32.h>
#endif
/* align addr on a size boundary - adjust address up/down if needed */
#define _ALIGN_UP(addr,size) (((addr)+((size)-1))&(~((size)-1)))
#define _ALIGN_DOWN(addr,size) ((addr)&(~((size)-1)))
/* align addr on a size boundary - adjust address up if needed */
#define _ALIGN(addr,size) _ALIGN_UP(addr,size)
/*
* Don't compare things with KERNELBASE or PAGE_OFFSET to test for
* "kernelness", use is_kernel_addr() - it should do what you want.
*/
#ifdef CONFIG_PPC_BOOK3E_64
#define is_kernel_addr(x) ((x) >= 0x8000000000000000ul)
#else
#define is_kernel_addr(x) ((x) >= PAGE_OFFSET)
#endif
/*
* Use the top bit of the higher-level page table entries to indicate whether
* the entries we point to contain hugepages. This works because we know that
* the page tables live in kernel space. If we ever decide to support having
* page tables at arbitrary addresses, this breaks and will have to change.
*/
#ifdef CONFIG_PPC64
#define PD_HUGE 0x8000000000000000
#else
#define PD_HUGE 0x80000000
#endif
/*
* Some number of bits at the level of the page table that points to
* a hugepte are used to encode the size. This masks those bits.
*/
#define HUGEPD_SHIFT_MASK 0x3f
#ifndef __ASSEMBLY__
#undef STRICT_MM_TYPECHECKS
#ifdef STRICT_MM_TYPECHECKS
/* These are used to make use of C type-checking. */
/* PTE level */
typedef struct { pte_basic_t pte; } pte_t;
#define pte_val(x) ((x).pte)
#define __pte(x) ((pte_t) { (x) })
/* 64k pages additionally define a bigger "real PTE" type that gathers
* the "second half" part of the PTE for pseudo 64k pages
*/
#if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_PPC_STD_MMU_64)
typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
#else
typedef struct { pte_t pte; } real_pte_t;
#endif
/* PMD level */
#ifdef CONFIG_PPC64
typedef struct { unsigned long pmd; } pmd_t;
#define pmd_val(x) ((x).pmd)
#define __pmd(x) ((pmd_t) { (x) })
/* PUD level exusts only on 4k pages */
#ifndef CONFIG_PPC_64K_PAGES
typedef struct { unsigned long pud; } pud_t;
#define pud_val(x) ((x).pud)
#define __pud(x) ((pud_t) { (x) })
#endif /* !CONFIG_PPC_64K_PAGES */
#endif /* CONFIG_PPC64 */
/* PGD level */
typedef struct { unsigned long pgd; } pgd_t;
#define pgd_val(x) ((x).pgd)
#define __pgd(x) ((pgd_t) { (x) })
/* Page protection bits */
typedef struct { unsigned long pgprot; } pgprot_t;
#define pgprot_val(x) ((x).pgprot)
#define __pgprot(x) ((pgprot_t) { (x) })
#else
/*
* .. while these make it easier on the compiler
*/
typedef pte_basic_t pte_t;
#define pte_val(x) (x)
#define __pte(x) (x)
#if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_PPC_STD_MMU_64)
typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
#else
typedef pte_t real_pte_t;
#endif
#ifdef CONFIG_PPC64
typedef unsigned long pmd_t;
#define pmd_val(x) (x)
#define __pmd(x) (x)
#ifndef CONFIG_PPC_64K_PAGES
typedef unsigned long pud_t;
#define pud_val(x) (x)
#define __pud(x) (x)
#endif /* !CONFIG_PPC_64K_PAGES */
#endif /* CONFIG_PPC64 */
typedef unsigned long pgd_t;
#define pgd_val(x) (x)
#define pgprot_val(x) (x)
typedef unsigned long pgprot_t;
#define __pgd(x) (x)
#define __pgprot(x) (x)
#endif
typedef struct { signed long pd; } hugepd_t;
#ifdef CONFIG_HUGETLB_PAGE
static inline int hugepd_ok(hugepd_t hpd)
{
return (hpd.pd > 0);
}
#define is_hugepd(pdep) (hugepd_ok(*((hugepd_t *)(pdep))))
#else /* CONFIG_HUGETLB_PAGE */
#define is_hugepd(pdep) 0
#endif /* CONFIG_HUGETLB_PAGE */
struct page;
extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg);
extern void copy_user_page(void *to, void *from, unsigned long vaddr,
struct page *p);
extern int page_is_ram(unsigned long pfn);
extern int devmem_is_allowed(unsigned long pfn);
#ifdef CONFIG_PPC_SMLPAR
void arch_free_page(struct page *page, int order);
#define HAVE_ARCH_FREE_PAGE
#endif
struct vm_area_struct;
typedef struct page *pgtable_t;
#include <asm-generic/memory_model.h>
#endif /* __ASSEMBLY__ */
#endif /* _ASM_POWERPC_PAGE_H */
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