/* * CRIS pgtable.h - macros and functions to manipulate page tables. */ #ifndef _CRIS_PGTABLE_H #define _CRIS_PGTABLE_H #include #include #ifndef __ASSEMBLY__ #include #include #endif #include /* * The Linux memory management assumes a three-level page table setup. On * CRIS, 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 CRIS page table tree. */ #ifndef __ASSEMBLY__ extern void paging_init(void); #endif /* 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 set_pgu(pudptr, pudval) (*(pudptr) = pudval) /* PGDIR_SHIFT determines the size of the area a second-level page table can * map. It is equal to the page size times the number of PTE's that fit in * a PMD page. A PTE is 4-bytes in CRIS. Hence the following number. */ #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 /* zero page used for uninitialized stuff */ #ifndef __ASSEMBLY__ extern unsigned long empty_zero_page; #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) #endif /* 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<>(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)) /* by removing the _PAGE_KERNEL bit from the comparision, the same pmd_bad * works for both _PAGE_TABLE and _KERNPG_TABLE pmd entries. */ #define pmd_bad(x) ((pmd_val(x) & (~PAGE_MASK & ~_PAGE_KERNEL)) != _PAGE_TABLE) #define pmd_present(x) (pmd_val(x) & _PAGE_PRESENT) #define pmd_clear(xp) do { pmd_val(*(xp)) = 0; } while (0) #ifndef __ASSEMBLY__ /* * The following only work if pte_present() is true. * Undefined behaviour if not.. */ static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_WRITE; } static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_MODIFIED; } 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_wrprotect(pte_t pte) { pte_val(pte) &= ~(_PAGE_WRITE | _PAGE_SILENT_WRITE); return pte; } static inline pte_t pte_mkclean(pte_t pte) { pte_val(pte) &= ~(_PAGE_MODIFIED | _PAGE_SILENT_WRITE); return pte; } static inline pte_t pte_mkold(pte_t pte) { pte_val(pte) &= ~(_PAGE_ACCESSED | _PAGE_SILENT_READ); return pte; } static inline pte_t pte_mkwrite(pte_t pte) { pte_val(pte) |= _PAGE_WRITE; if (pte_val(pte) & _PAGE_MODIFIED) pte_val(pte) |= _PAGE_SILENT_WRITE; return pte; } static inline pte_t pte_mkdirty(pte_t pte) { pte_val(pte) |= _PAGE_MODIFIED; if (pte_val(pte) & _PAGE_WRITE) pte_val(pte) |= _PAGE_SILENT_WRITE; return pte; } static inline pte_t pte_mkyoung(pte_t pte) { pte_val(pte) |= _PAGE_ACCESSED; if (pte_val(pte) & _PAGE_READ) { pte_val(pte) |= _PAGE_SILENT_READ; if ((pte_val(pte) & (_PAGE_WRITE | _PAGE_MODIFIED)) == (_PAGE_WRITE | _PAGE_MODIFIED)) pte_val(pte) |= _PAGE_SILENT_WRITE; } return pte; } static inline pte_t pte_mkspecial(pte_t pte) { 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 0x4xxxxxxx 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) = _PAGE_TABLE | (unsigned long) ptep; } #define pmd_page(pmd) (pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT)) #define pmd_page_vaddr(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)) /* to find an entry in a page-table-directory */ static inline pgd_t * pgd_offset(const struct mm_struct *mm, unsigned long address) { return 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) /* Find an entry in the third-level page table.. */ #define __pte_offset(address) \ (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) #define pte_offset_kernel(dir, address) \ ((pte_t *) pmd_page_vaddr(*(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)(__va((x).pte)) >> PAGE_SHIFT) #define pfn_pte(pfn, prot) __pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot)) #define pte_ERROR(e) \ printk("%s:%d: bad pte %p(%08lx).\n", __FILE__, __LINE__, &(e), pte_val(e)) #define pgd_ERROR(e) \ printk("%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 */ /* * CRIS 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) { } /* 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 /* * No page table caches to initialise */ #define pgtable_cache_init() do { } while (0) #define pte_to_pgoff(x) (pte_val(x) >> 6) #define pgoff_to_pte(x) __pte(((x) << 6) | _PAGE_FILE) typedef pte_t *pte_addr_t; #endif /* __ASSEMBLY__ */ #endif /* _CRIS_PGTABLE_H */