/* * 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 #define __ARCH_USE_5LEVEL_HACK #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 << (32-PGDIR_SHIFT)) /* 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 0UL /* * 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_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_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 */ struct vm_area_struct; /* * 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 }) #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 */