/* MN10300 Page table manipulators and constants * * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public Licence * as published by the Free Software Foundation; either version * 2 of the Licence, or (at your option) any later version. * * * The Linux memory management assumes a three-level page table setup. On * the i386, we use that, but "fold" the mid level into the top-level page * table, so that we physically have the same two-level page table as the * i386 mmu expects. * * This file contains the functions and defines necessary to modify and use * the i386 page table tree for the purposes of the MN10300 TLB handler * functions. */ #ifndef _ASM_PGTABLE_H #define _ASM_PGTABLE_H #include #ifndef __ASSEMBLY__ #include #include #include #include #include #include #include /* * ZERO_PAGE is a global shared page that is always zero: used * for zero-mapped memory areas etc.. */ #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) extern unsigned long empty_zero_page[1024]; extern spinlock_t pgd_lock; extern struct page *pgd_list; extern void pmd_ctor(void *, struct kmem_cache *, unsigned long); extern void pgtable_cache_init(void); extern void paging_init(void); #endif /* !__ASSEMBLY__ */ /* * The Linux mn10300 paging architecture only implements both the traditional * 2-level page tables */ #define PGDIR_SHIFT 22 #define PTRS_PER_PGD 1024 #define PTRS_PER_PUD 1 /* we don't really have any PUD physically */ #define PTRS_PER_PMD 1 /* we don't really have any PMD physically */ #define PTRS_PER_PTE 1024 #define PGD_SIZE PAGE_SIZE #define PMD_SIZE (1UL << PMD_SHIFT) #define PGDIR_SIZE (1UL << PGDIR_SHIFT) #define PGDIR_MASK (~(PGDIR_SIZE - 1)) #define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE) #define FIRST_USER_ADDRESS 0 #define USER_PGD_PTRS (PAGE_OFFSET >> PGDIR_SHIFT) #define KERNEL_PGD_PTRS (PTRS_PER_PGD - USER_PGD_PTRS) #define TWOLEVEL_PGDIR_SHIFT 22 #define BOOT_USER_PGD_PTRS (__PAGE_OFFSET >> TWOLEVEL_PGDIR_SHIFT) #define BOOT_KERNEL_PGD_PTRS (1024 - BOOT_USER_PGD_PTRS) #ifndef __ASSEMBLY__ extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; #endif /* * Unfortunately, due to the way the MMU works on the MN10300, the vmalloc VM * area has to be in the lower half of the virtual address range (the upper * half is not translated through the TLB). * * So in this case, the vmalloc area goes at the bottom of the address map * (leaving a hole at the very bottom to catch addressing errors), and * userspace starts immediately above. * * The vmalloc() routines also leaves a hole of 4kB between each vmalloced * area to catch addressing errors. */ #define VMALLOC_OFFSET (8 * 1024 * 1024) #define VMALLOC_START (0x70000000) #define VMALLOC_END (0x7C000000) #ifndef __ASSEMBLY__ extern pte_t kernel_vmalloc_ptes[(VMALLOC_END - VMALLOC_START) / PAGE_SIZE]; #endif /* IPTEL/DPTEL bit assignments */ #define _PAGE_BIT_VALID xPTEL_V_BIT #define _PAGE_BIT_ACCESSED xPTEL_UNUSED1_BIT /* mustn't be loaded into IPTEL/DPTEL */ #define _PAGE_BIT_NX xPTEL_UNUSED2_BIT /* mustn't be loaded into IPTEL/DPTEL */ #define _PAGE_BIT_CACHE xPTEL_C_BIT #define _PAGE_BIT_PRESENT xPTEL_PV_BIT #define _PAGE_BIT_DIRTY xPTEL_D_BIT #define _PAGE_BIT_GLOBAL xPTEL_G_BIT #define _PAGE_VALID xPTEL_V #define _PAGE_ACCESSED xPTEL_UNUSED1 #define _PAGE_NX xPTEL_UNUSED2 /* no-execute bit */ #define _PAGE_CACHE xPTEL_C #define _PAGE_PRESENT xPTEL_PV #define _PAGE_DIRTY xPTEL_D #define _PAGE_PROT xPTEL_PR #define _PAGE_PROT_RKNU xPTEL_PR_ROK #define _PAGE_PROT_WKNU xPTEL_PR_RWK #define _PAGE_PROT_RKRU xPTEL_PR_ROK_ROU #define _PAGE_PROT_WKRU xPTEL_PR_RWK_ROU #define _PAGE_PROT_WKWU xPTEL_PR_RWK_RWU #define _PAGE_GLOBAL xPTEL_G #define _PAGE_PSE xPTEL_PS_4Mb /* 4MB page */ #define _PAGE_FILE xPTEL_UNUSED1_BIT /* set:pagecache unset:swap */ #define __PAGE_PROT_UWAUX 0x040 #define __PAGE_PROT_USER 0x080 #define __PAGE_PROT_WRITE 0x100 #define _PAGE_PRESENTV (_PAGE_PRESENT|_PAGE_VALID) #define _PAGE_PROTNONE 0x000 /* If not present */ #ifndef __ASSEMBLY__ #define VMALLOC_VMADDR(x) ((unsigned long)(x)) #define _PAGE_TABLE (_PAGE_PRESENTV | _PAGE_PROT_WKNU | _PAGE_ACCESSED | _PAGE_DIRTY) #define _PAGE_CHG_MASK (PTE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY) #define __PAGE_NONE (_PAGE_PRESENTV | _PAGE_PROT_RKNU | _PAGE_ACCESSED | _PAGE_CACHE) #define __PAGE_SHARED (_PAGE_PRESENTV | _PAGE_PROT_WKWU | _PAGE_ACCESSED | _PAGE_CACHE) #define __PAGE_COPY (_PAGE_PRESENTV | _PAGE_PROT_RKRU | _PAGE_ACCESSED | _PAGE_CACHE) #define __PAGE_READONLY (_PAGE_PRESENTV | _PAGE_PROT_RKRU | _PAGE_ACCESSED | _PAGE_CACHE) #define PAGE_NONE __pgprot(__PAGE_NONE | _PAGE_NX) #define PAGE_SHARED_NOEXEC __pgprot(__PAGE_SHARED | _PAGE_NX) #define PAGE_COPY_NOEXEC __pgprot(__PAGE_COPY | _PAGE_NX) #define PAGE_READONLY_NOEXEC __pgprot(__PAGE_READONLY | _PAGE_NX) #define PAGE_SHARED_EXEC __pgprot(__PAGE_SHARED) #define PAGE_COPY_EXEC __pgprot(__PAGE_COPY) #define PAGE_READONLY_EXEC __pgprot(__PAGE_READONLY) #define PAGE_COPY PAGE_COPY_NOEXEC #define PAGE_READONLY PAGE_READONLY_NOEXEC #define PAGE_SHARED PAGE_SHARED_EXEC #define __PAGE_KERNEL_BASE (_PAGE_PRESENTV | _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_GLOBAL) #define __PAGE_KERNEL (__PAGE_KERNEL_BASE | _PAGE_PROT_WKNU | _PAGE_CACHE | _PAGE_NX) #define __PAGE_KERNEL_NOCACHE (__PAGE_KERNEL_BASE | _PAGE_PROT_WKNU | _PAGE_NX) #define __PAGE_KERNEL_EXEC (__PAGE_KERNEL & ~_PAGE_NX) #define __PAGE_KERNEL_RO (__PAGE_KERNEL_BASE | _PAGE_PROT_RKNU | _PAGE_CACHE | _PAGE_NX) #define __PAGE_KERNEL_LARGE (__PAGE_KERNEL | _PAGE_PSE) #define __PAGE_KERNEL_LARGE_EXEC (__PAGE_KERNEL_EXEC | _PAGE_PSE) #define PAGE_KERNEL __pgprot(__PAGE_KERNEL) #define PAGE_KERNEL_RO __pgprot(__PAGE_KERNEL_RO) #define PAGE_KERNEL_EXEC __pgprot(__PAGE_KERNEL_EXEC) #define PAGE_KERNEL_NOCACHE __pgprot(__PAGE_KERNEL_NOCACHE) #define PAGE_KERNEL_LARGE __pgprot(__PAGE_KERNEL_LARGE) #define PAGE_KERNEL_LARGE_EXEC __pgprot(__PAGE_KERNEL_LARGE_EXEC) /* * Whilst the MN10300 can do page protection for execute (given separate data * and insn TLBs), we are not supporting it at the moment. Write permission, * however, always implies read permission (but not execute permission). */ #define __P000 PAGE_NONE #define __P001 PAGE_READONLY_NOEXEC #define __P010 PAGE_COPY_NOEXEC #define __P011 PAGE_COPY_NOEXEC #define __P100 PAGE_READONLY_EXEC #define __P101 PAGE_READONLY_EXEC #define __P110 PAGE_COPY_EXEC #define __P111 PAGE_COPY_EXEC #define __S000 PAGE_NONE #define __S001 PAGE_READONLY_NOEXEC #define __S010 PAGE_SHARED_NOEXEC #define __S011 PAGE_SHARED_NOEXEC #define __S100 PAGE_READONLY_EXEC #define __S101 PAGE_READONLY_EXEC #define __S110 PAGE_SHARED_EXEC #define __S111 PAGE_SHARED_EXEC /* * Define this to warn about kernel memory accesses that are * done without a 'verify_area(VERIFY_WRITE,..)' */ #undef TEST_VERIFY_AREA #define pte_present(x) (pte_val(x) & _PAGE_VALID) #define pte_clear(mm, addr, xp) \ do { \ set_pte_at((mm), (addr), (xp), __pte(0)); \ } while (0) #define pmd_none(x) (!pmd_val(x)) #define pmd_present(x) (!pmd_none(x)) #define pmd_clear(xp) do { set_pmd(xp, __pmd(0)); } while (0) #define pmd_bad(x) 0 #define pages_to_mb(x) ((x) >> (20 - PAGE_SHIFT)) #ifndef __ASSEMBLY__ /* * The following only work if pte_present() is true. * Undefined behaviour if not.. */ static inline int pte_user(pte_t pte) { return pte_val(pte) & __PAGE_PROT_USER; } static inline int pte_read(pte_t pte) { return pte_val(pte) & __PAGE_PROT_USER; } static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY; } static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; } static inline int pte_write(pte_t pte) { return pte_val(pte) & __PAGE_PROT_WRITE; } static inline int pte_special(pte_t pte){ return 0; } /* * The following only works if pte_present() is not true. */ static inline int pte_file(pte_t pte) { return pte_val(pte) & _PAGE_FILE; } static inline pte_t pte_rdprotect(pte_t pte) { pte_val(pte) &= ~(__PAGE_PROT_USER|__PAGE_PROT_UWAUX); return pte; } static inline pte_t pte_exprotect(pte_t pte) { pte_val(pte) |= _PAGE_NX; return pte; } static inline pte_t pte_wrprotect(pte_t pte) { pte_val(pte) &= ~(__PAGE_PROT_WRITE|__PAGE_PROT_UWAUX); return pte; } static inline pte_t pte_mkclean(pte_t pte) { pte_val(pte) &= ~_PAGE_DIRTY; return pte; } static inline pte_t pte_mkold(pte_t pte) { pte_val(pte) &= ~_PAGE_ACCESSED; return pte; } static inline pte_t pte_mkdirty(pte_t pte) { pte_val(pte) |= _PAGE_DIRTY; return pte; } static inline pte_t pte_mkyoung(pte_t pte) { pte_val(pte) |= _PAGE_ACCESSED; return pte; } static inline pte_t pte_mkexec(pte_t pte) { pte_val(pte) &= ~_PAGE_NX; return pte; } static inline pte_t pte_mkread(pte_t pte) { pte_val(pte) |= __PAGE_PROT_USER; if (pte_write(pte)) pte_val(pte) |= __PAGE_PROT_UWAUX; return pte; } static inline pte_t pte_mkwrite(pte_t pte) { pte_val(pte) |= __PAGE_PROT_WRITE; if (pte_val(pte) & __PAGE_PROT_USER) pte_val(pte) |= __PAGE_PROT_UWAUX; return pte; } static inline pte_t pte_mkspecial(pte_t pte) { return pte; } #define pte_ERROR(e) \ printk(KERN_ERR "%s:%d: bad pte %08lx.\n", \ __FILE__, __LINE__, pte_val(e)) #define pgd_ERROR(e) \ printk(KERN_ERR "%s:%d: bad pgd %08lx.\n", \ __FILE__, __LINE__, pgd_val(e)) /* * The "pgd_xxx()" functions here are trivial for a folded two-level * setup: the pgd is never bad, and a pmd always exists (as it's folded * into the pgd entry) */ #define pgd_clear(xp) do { } while (0) /* * Certain architectures need to do special things when PTEs * within a page table are directly modified. Thus, the following * hook is made available. */ #define set_pte(pteptr, pteval) (*(pteptr) = pteval) #define set_pte_at(mm, addr, ptep, pteval) set_pte((ptep), (pteval)) #define set_pte_atomic(pteptr, pteval) set_pte((pteptr), (pteval)) /* * (pmds are folded into pgds so this doesn't get actually called, * but the define is needed for a generic inline function.) */ #define set_pmd(pmdptr, pmdval) (*(pmdptr) = pmdval) #define ptep_get_and_clear(mm, addr, ptep) \ __pte(xchg(&(ptep)->pte, 0)) #define pte_same(a, b) (pte_val(a) == pte_val(b)) #define pte_page(x) pfn_to_page(pte_pfn(x)) #define pte_none(x) (!pte_val(x)) #define pte_pfn(x) ((unsigned long) (pte_val(x) >> PAGE_SHIFT)) #define __pfn_addr(pfn) ((pfn) << PAGE_SHIFT) #define pfn_pte(pfn, prot) __pte(__pfn_addr(pfn) | pgprot_val(prot)) #define pfn_pmd(pfn, prot) __pmd(__pfn_addr(pfn) | pgprot_val(prot)) /* * All present user pages are user-executable: */ static inline int pte_exec(pte_t pte) { return pte_user(pte); } /* * All present pages are kernel-executable: */ static inline int pte_exec_kernel(pte_t pte) { return 1; } /* * Bits 0 and 1 are taken, split up the 29 bits of offset * into this range: */ #define PTE_FILE_MAX_BITS 29 #define pte_to_pgoff(pte) (pte_val(pte) >> 2) #define pgoff_to_pte(off) __pte((off) << 2 | _PAGE_FILE) /* Encode and de-code a swap entry */ #define __swp_type(x) (((x).val >> 2) & 0x3f) #define __swp_offset(x) ((x).val >> 8) #define __swp_entry(type, offset) \ ((swp_entry_t) { ((type) << 2) | ((offset) << 8) }) #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) #define __swp_entry_to_pte(x) __pte((x).val) static inline int ptep_test_and_clear_dirty(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep) { if (!pte_dirty(*ptep)) return 0; return test_and_clear_bit(_PAGE_BIT_DIRTY, &ptep->pte); } static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep) { if (!pte_young(*ptep)) return 0; return test_and_clear_bit(_PAGE_BIT_ACCESSED, &ptep->pte); } static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep) { pte_val(*ptep) &= ~(__PAGE_PROT_WRITE|__PAGE_PROT_UWAUX); } static inline void ptep_mkdirty(pte_t *ptep) { set_bit(_PAGE_BIT_DIRTY, &ptep->pte); } /* * Macro to mark a page protection value as "uncacheable". On processors which * do not support it, this is a no-op. */ #define pgprot_noncached(prot) __pgprot(pgprot_val(prot) | _PAGE_CACHE) /* * Conversion functions: convert a page and protection to a page entry, * and a page entry and page directory to the page they refer to. */ #define mk_pte(page, pgprot) pfn_pte(page_to_pfn(page), (pgprot)) #define mk_pte_huge(entry) \ ((entry).pte |= _PAGE_PRESENT | _PAGE_PSE | _PAGE_VALID) static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) { pte_val(pte) &= _PAGE_CHG_MASK; pte_val(pte) |= pgprot_val(newprot); return pte; } #define page_pte(page) page_pte_prot((page), __pgprot(0)) #define pmd_page_kernel(pmd) \ ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK)) #define pmd_page(pmd) pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT) #define pmd_large(pmd) \ ((pmd_val(pmd) & (_PAGE_PSE | _PAGE_PRESENT)) == \ (_PAGE_PSE | _PAGE_PRESENT)) /* * the pgd page can be thought of an array like this: pgd_t[PTRS_PER_PGD] * * this macro returns the index of the entry in the pgd page which would * control the given virtual address */ #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1)) /* * pgd_offset() returns a (pgd_t *) * pgd_index() is used get the offset into the pgd page's array of pgd_t's; */ #define pgd_offset(mm, address) ((mm)->pgd + pgd_index(address)) /* * a shortcut which implies the use of the kernel's pgd, instead * of a process's */ #define pgd_offset_k(address) pgd_offset(&init_mm, address) /* * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD] * * this macro returns the index of the entry in the pmd page which would * control the given virtual address */ #define pmd_index(address) \ (((address) >> PMD_SHIFT) & (PTRS_PER_PMD - 1)) /* * the pte page can be thought of an array like this: pte_t[PTRS_PER_PTE] * * this macro returns the index of the entry in the pte page which would * control the given virtual address */ #define pte_index(address) \ (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) #define pte_offset_kernel(dir, address) \ ((pte_t *) pmd_page_kernel(*(dir)) + pte_index(address)) /* * Make a given kernel text page executable/non-executable. * Returns the previous executability setting of that page (which * is used to restore the previous state). Used by the SMP bootup code. * NOTE: this is an __init function for security reasons. */ static inline int set_kernel_exec(unsigned long vaddr, int enable) { return 0; } #define pte_offset_map(dir, address) \ ((pte_t *) page_address(pmd_page(*(dir))) + pte_index(address)) #define pte_offset_map_nested(dir, address) pte_offset_map(dir, address) #define pte_unmap(pte) do {} while (0) #define pte_unmap_nested(pte) do {} while (0) /* * The MN10300 has external MMU info in the form of a TLB: this is adapted from * the kernel page tables containing the necessary information by tlb-mn10300.S */ extern void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t pte); #endif /* !__ASSEMBLY__ */ #define kern_addr_valid(addr) (1) #define io_remap_pfn_range(vma, vaddr, pfn, size, prot) \ remap_pfn_range((vma), (vaddr), (pfn), (size), (prot)) #define MK_IOSPACE_PFN(space, pfn) (pfn) #define GET_IOSPACE(pfn) 0 #define GET_PFN(pfn) (pfn) #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY #define __HAVE_ARCH_PTEP_GET_AND_CLEAR #define __HAVE_ARCH_PTEP_SET_WRPROTECT #define __HAVE_ARCH_PTEP_MKDIRTY #define __HAVE_ARCH_PTE_SAME #include #endif /* !__ASSEMBLY__ */ #endif /* _ASM_PGTABLE_H */