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Diffstat (limited to 'arch/openrisc/include/asm/pgtable.h')
| -rw-r--r-- | arch/openrisc/include/asm/pgtable.h | 459 |
1 files changed, 459 insertions, 0 deletions
diff --git a/arch/openrisc/include/asm/pgtable.h b/arch/openrisc/include/asm/pgtable.h new file mode 100644 index 00000000000..37bf6a3ef8f --- /dev/null +++ b/arch/openrisc/include/asm/pgtable.h @@ -0,0 +1,459 @@ +/* + * OpenRISC Linux + * + * Linux architectural port borrowing liberally from similar works of + * others. All original copyrights apply as per the original source + * declaration. + * + * OpenRISC implementation: + * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com> + * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se> + * et al. + * + * 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. + */ + +/* or32 pgtable.h - macros and functions to manipulate page tables + * + * Based on: + * include/asm-cris/pgtable.h + */ + +#ifndef __ASM_OPENRISC_PGTABLE_H +#define __ASM_OPENRISC_PGTABLE_H + +#include <asm-generic/pgtable-nopmd.h> + +#ifndef __ASSEMBLY__ +#include <asm/mmu.h> +#include <asm/fixmap.h> + +/* + * The Linux memory management assumes a three-level page table setup. On + * or32, we use that, but "fold" the mid level into the top-level page + * table. Since the MMU TLB is software loaded through an interrupt, it + * supports any page table structure, so we could have used a three-level + * setup, but for the amounts of memory we normally use, a two-level is + * probably more efficient. + * + * This file contains the functions and defines necessary to modify and use + * the or32 page table tree. + */ + +extern void paging_init(void); + +/* Certain architectures need to do special things when pte's + * 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) +/* + * (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 PGDIR_SHIFT (PAGE_SHIFT + (PAGE_SHIFT-2)) +#define PGDIR_SIZE (1UL << PGDIR_SHIFT) +#define PGDIR_MASK (~(PGDIR_SIZE-1)) + +/* + * entries per page directory level: we use a two-level, so + * we don't really have any PMD directory physically. + * pointers are 4 bytes so we can use the page size and + * divide it by 4 (shift by 2). + */ +#define PTRS_PER_PTE (1UL << (PAGE_SHIFT-2)) + +#define PTRS_PER_PGD (1UL << (PAGE_SHIFT-2)) + +/* calculate how many PGD entries a user-level program can use + * the first mappable virtual address is 0 + * (TASK_SIZE is the maximum virtual address space) + */ + +#define USER_PTRS_PER_PGD (TASK_SIZE/PGDIR_SIZE) +#define FIRST_USER_ADDRESS 0 + +/* + * Kernels own virtual memory area. + */ + +/* + * The size and location of the vmalloc area are chosen so that modules + * placed in this area aren't more than a 28-bit signed offset from any + * kernel functions that they may need. This greatly simplifies handling + * of the relocations for l.j and l.jal instructions as we don't need to + * introduce any trampolines for reaching "distant" code. + * + * 64 MB of vmalloc area is comparable to what's available on other arches. + */ + +#define VMALLOC_START (PAGE_OFFSET-0x04000000) +#define VMALLOC_END (PAGE_OFFSET) +#define VMALLOC_VMADDR(x) ((unsigned long)(x)) + +/* Define some higher level generic page attributes. + * + * If you change _PAGE_CI definition be sure to change it in + * io.h for ioremap_nocache() too. + */ + +/* + * An OR32 PTE looks like this: + * + * | 31 ... 10 | 9 | 8 ... 6 | 5 | 4 | 3 | 2 | 1 | 0 | + * Phys pg.num L PP Index D A WOM WBC CI CC + * + * L : link + * PPI: Page protection index + * D : Dirty + * A : Accessed + * WOM: Weakly ordered memory + * WBC: Write-back cache + * CI : Cache inhibit + * CC : Cache coherent + * + * The protection bits below should correspond to the layout of the actual + * PTE as per above + */ + +#define _PAGE_CC 0x001 /* software: pte contains a translation */ +#define _PAGE_CI 0x002 /* cache inhibit */ +#define _PAGE_WBC 0x004 /* write back cache */ +#define _PAGE_FILE 0x004 /* set: pagecache, unset: swap (when !PRESENT) */ +#define _PAGE_WOM 0x008 /* weakly ordered memory */ + +#define _PAGE_A 0x010 /* accessed */ +#define _PAGE_D 0x020 /* dirty */ +#define _PAGE_URE 0x040 /* user read enable */ +#define _PAGE_UWE 0x080 /* user write enable */ + +#define _PAGE_SRE 0x100 /* superuser read enable */ +#define _PAGE_SWE 0x200 /* superuser write enable */ +#define _PAGE_EXEC 0x400 /* software: page is executable */ +#define _PAGE_U_SHARED 0x800 /* software: page is shared in user space */ + +/* 0x001 is cache coherency bit, which should always be set to + * 1 - for SMP (when we support it) + * 0 - otherwise + * + * we just reuse this bit in software for _PAGE_PRESENT and + * force it to 0 when loading it into TLB. + */ +#define _PAGE_PRESENT _PAGE_CC +#define _PAGE_USER _PAGE_URE +#define _PAGE_WRITE (_PAGE_UWE | _PAGE_SWE) +#define _PAGE_DIRTY _PAGE_D +#define _PAGE_ACCESSED _PAGE_A +#define _PAGE_NO_CACHE _PAGE_CI +#define _PAGE_SHARED _PAGE_U_SHARED +#define _PAGE_READ (_PAGE_URE | _PAGE_SRE) + +#define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY) +#define _PAGE_BASE (_PAGE_PRESENT | _PAGE_ACCESSED) +#define _PAGE_ALL (_PAGE_PRESENT | _PAGE_ACCESSED) +#define _KERNPG_TABLE \ + (_PAGE_BASE | _PAGE_SRE | _PAGE_SWE | _PAGE_ACCESSED | _PAGE_DIRTY) + +#define PAGE_NONE __pgprot(_PAGE_ALL) +#define PAGE_READONLY __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE) +#define PAGE_READONLY_X __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE | _PAGE_EXEC) +#define PAGE_SHARED \ + __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE | _PAGE_UWE | _PAGE_SWE \ + | _PAGE_SHARED) +#define PAGE_SHARED_X \ + __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE | _PAGE_UWE | _PAGE_SWE \ + | _PAGE_SHARED | _PAGE_EXEC) +#define PAGE_COPY __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE) +#define PAGE_COPY_X __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE | _PAGE_EXEC) + +#define PAGE_KERNEL \ + __pgprot(_PAGE_ALL | _PAGE_SRE | _PAGE_SWE \ + | _PAGE_SHARED | _PAGE_DIRTY | _PAGE_EXEC) +#define PAGE_KERNEL_RO \ + __pgprot(_PAGE_ALL | _PAGE_SRE \ + | _PAGE_SHARED | _PAGE_DIRTY | _PAGE_EXEC) +#define PAGE_KERNEL_NOCACHE \ + __pgprot(_PAGE_ALL | _PAGE_SRE | _PAGE_SWE \ + | _PAGE_SHARED | _PAGE_DIRTY | _PAGE_EXEC | _PAGE_CI) + +#define __P000 PAGE_NONE +#define __P001 PAGE_READONLY_X +#define __P010 PAGE_COPY +#define __P011 PAGE_COPY_X +#define __P100 PAGE_READONLY +#define __P101 PAGE_READONLY_X +#define __P110 PAGE_COPY +#define __P111 PAGE_COPY_X + +#define __S000 PAGE_NONE +#define __S001 PAGE_READONLY_X +#define __S010 PAGE_SHARED +#define __S011 PAGE_SHARED_X +#define __S100 PAGE_READONLY +#define __S101 PAGE_READONLY_X +#define __S110 PAGE_SHARED +#define __S111 PAGE_SHARED_X + +/* zero page used for uninitialized stuff */ +extern unsigned long empty_zero_page[2048]; +#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) + +/* number of bits that fit into a memory pointer */ +#define BITS_PER_PTR (8*sizeof(unsigned long)) + +/* to align the pointer to a pointer address */ +#define PTR_MASK (~(sizeof(void *)-1)) + +/* sizeof(void*)==1<<SIZEOF_PTR_LOG2 */ +/* 64-bit machines, beware! SRB. */ +#define SIZEOF_PTR_LOG2 2 + +/* to find an entry in a page-table */ +#define PAGE_PTR(address) \ +((unsigned long)(address)>>(PAGE_SHIFT-SIZEOF_PTR_LOG2)&PTR_MASK&~PAGE_MASK) + +/* to set the page-dir */ +#define SET_PAGE_DIR(tsk, pgdir) + +#define pte_none(x) (!pte_val(x)) +#define pte_present(x) (pte_val(x) & _PAGE_PRESENT) +#define pte_clear(mm, addr, xp) do { pte_val(*(xp)) = 0; } while (0) + +#define pmd_none(x) (!pmd_val(x)) +#define pmd_bad(x) ((pmd_val(x) & (~PAGE_MASK)) != _KERNPG_TABLE) +#define pmd_present(x) (pmd_val(x) & _PAGE_PRESENT) +#define pmd_clear(xp) do { pmd_val(*(xp)) = 0; } while (0) + +/* + * The following only work if pte_present() is true. + * Undefined behaviour if not.. + */ + +static inline int pte_read(pte_t pte) { return pte_val(pte) & _PAGE_READ; } +static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_WRITE; } +static inline int pte_exec(pte_t pte) { return pte_val(pte) & _PAGE_EXEC; } +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_file(pte_t pte) { return pte_val(pte) & _PAGE_FILE; } +static inline int pte_special(pte_t pte) { return 0; } +static inline pte_t pte_mkspecial(pte_t pte) { return pte; } + +static inline pte_t pte_wrprotect(pte_t pte) +{ + pte_val(pte) &= ~(_PAGE_WRITE); + return pte; +} + +static inline pte_t pte_rdprotect(pte_t pte) +{ + pte_val(pte) &= ~(_PAGE_READ); + return pte; +} + +static inline pte_t pte_exprotect(pte_t pte) +{ + pte_val(pte) &= ~(_PAGE_EXEC); + 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_mkwrite(pte_t pte) +{ + pte_val(pte) |= _PAGE_WRITE; + return pte; +} + +static inline pte_t pte_mkread(pte_t pte) +{ + pte_val(pte) |= _PAGE_READ; + return pte; +} + +static inline pte_t pte_mkexec(pte_t pte) +{ + pte_val(pte) |= _PAGE_EXEC; + 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; +} + +/* + * Conversion functions: convert a page and protection to a page entry, + * and a page entry and page directory to the page they refer to. + */ + +/* What actually goes as arguments to the various functions is less than + * obvious, but a rule of thumb is that struct page's goes as struct page *, + * really physical DRAM addresses are unsigned long's, and DRAM "virtual" + * addresses (the 0xc0xxxxxx's) goes as void *'s. + */ + +static inline pte_t __mk_pte(void *page, pgprot_t pgprot) +{ + pte_t pte; + /* the PTE needs a physical address */ + pte_val(pte) = __pa(page) | pgprot_val(pgprot); + return pte; +} + +#define mk_pte(page, pgprot) __mk_pte(page_address(page), (pgprot)) + +#define mk_pte_phys(physpage, pgprot) \ +({ \ + pte_t __pte; \ + \ + pte_val(__pte) = (physpage) + pgprot_val(pgprot); \ + __pte; \ +}) + +static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) +{ + pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot); + return pte; +} + + +/* + * pte_val refers to a page in the 0x0xxxxxxx physical DRAM interval + * __pte_page(pte_val) refers to the "virtual" DRAM interval + * pte_pagenr refers to the page-number counted starting from the virtual + * DRAM start + */ + +static inline unsigned long __pte_page(pte_t pte) +{ + /* the PTE contains a physical address */ + return (unsigned long)__va(pte_val(pte) & PAGE_MASK); +} + +#define pte_pagenr(pte) ((__pte_page(pte) - PAGE_OFFSET) >> PAGE_SHIFT) + +/* permanent address of a page */ + +#define __page_address(page) (PAGE_OFFSET + (((page) - mem_map) << PAGE_SHIFT)) +#define pte_page(pte) (mem_map+pte_pagenr(pte)) + +/* + * only the pte's themselves need to point to physical DRAM (see above) + * the pagetable links are purely handled within the kernel SW and thus + * don't need the __pa and __va transformations. + */ +static inline void pmd_set(pmd_t *pmdp, pte_t *ptep) +{ + pmd_val(*pmdp) = _KERNPG_TABLE | (unsigned long) ptep; +} + +#define pmd_page(pmd) (pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT)) +#define pmd_page_kernel(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK)) + +/* to find an entry in a page-table-directory. */ +#define pgd_index(address) ((address >> PGDIR_SHIFT) & (PTRS_PER_PGD-1)) + +#define __pgd_offset(address) pgd_index(address) + +#define pgd_offset(mm, address) ((mm)->pgd+pgd_index(address)) + +/* to find an entry in a kernel page-table-directory */ +#define pgd_offset_k(address) pgd_offset(&init_mm, address) + +#define __pmd_offset(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_offset(address) \ + (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) +#define pte_offset_kernel(dir, address) \ + ((pte_t *) pmd_page_kernel(*(dir)) + __pte_offset(address)) +#define pte_offset_map(dir, address) \ + ((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(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) +#define pte_pfn(x) ((unsigned long)(((x).pte)) >> PAGE_SHIFT) +#define pfn_pte(pfn, prot) __pte((((pfn) << PAGE_SHIFT)) | pgprot_val(prot)) + +#define pte_ERROR(e) \ + printk(KERN_ERR "%s:%d: bad pte %p(%08lx).\n", \ + __FILE__, __LINE__, &(e), pte_val(e)) +#define pgd_ERROR(e) \ + printk(KERN_ERR "%s:%d: bad pgd %p(%08lx).\n", \ + __FILE__, __LINE__, &(e), pgd_val(e)) + +extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; /* defined in head.S */ + +/* + * or32 doesn't have any external MMU info: the kernel page + * tables contain all the necessary information. + * + * Actually I am not sure on what this could be used for. + */ +static inline void update_mmu_cache(struct vm_area_struct *vma, + unsigned long address, pte_t *pte) +{ +} + +/* __PHX__ FIXME, SWAP, this probably doesn't work */ + +/* Encode and de-code a swap entry (must be !pte_none(e) && !pte_present(e)) */ +/* Since the PAGE_PRESENT bit is bit 4, we can use the bits above */ + +#define __swp_type(x) (((x).val >> 5) & 0x7f) +#define __swp_offset(x) ((x).val >> 12) +#define __swp_entry(type, offset) \ + ((swp_entry_t) { ((type) << 5) | ((offset) << 12) }) +#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) +#define __swp_entry_to_pte(x) ((pte_t) { (x).val }) + +/* Encode and decode a nonlinear file mapping entry */ + +#define PTE_FILE_MAX_BITS 26 +#define pte_to_pgoff(x) (pte_val(x) >> 6) +#define pgoff_to_pte(x) __pte(((x) << 6) | _PAGE_FILE) + +#define kern_addr_valid(addr) (1) + +#include <asm-generic/pgtable.h> + +/* + * No page table caches to initialise + */ +#define pgtable_cache_init() do { } while (0) + +typedef pte_t *pte_addr_t; + +#endif /* __ASSEMBLY__ */ +#endif /* __ASM_OPENRISC_PGTABLE_H */ |