diff options
Diffstat (limited to 'include/asm-cris/pgtable.h')
| -rw-r--r-- | include/asm-cris/pgtable.h | 352 |
1 files changed, 352 insertions, 0 deletions
diff --git a/include/asm-cris/pgtable.h b/include/asm-cris/pgtable.h new file mode 100644 index 000000000000..957dd92d108d --- /dev/null +++ b/include/asm-cris/pgtable.h @@ -0,0 +1,352 @@ +/* + * CRIS pgtable.h - macros and functions to manipulate page tables. + */ + +#ifndef _CRIS_PGTABLE_H +#define _CRIS_PGTABLE_H + +#include <asm-generic/4level-fixup.h> + +#ifndef __ASSEMBLY__ +#include <linux/config.h> +#include <linux/sched.h> +#include <asm/mmu.h> +#endif +#include <asm/arch/pgtable.h> + +/* + * 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_pgd(pgdptr, pgdval) (*(pgdptr) = pgdval) + +/* PMD_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 PMD_SHIFT (PAGE_SHIFT + (PAGE_SHIFT-2)) +#define PMD_SIZE (1UL << PMD_SHIFT) +#define PMD_MASK (~(PMD_SIZE-1)) + +/* PGDIR_SHIFT determines what a third-level page table entry can map. + * Since we fold into a two-level structure, this is the same as PMD_SHIFT. + */ + +#define PGDIR_SHIFT PMD_SHIFT +#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_PMD 1 +#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_PGD_NR 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<<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)) +/* 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 "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) + */ +extern inline int pgd_none(pgd_t pgd) { return 0; } +extern inline int pgd_bad(pgd_t pgd) { return 0; } +extern inline int pgd_present(pgd_t pgd) { return 1; } +extern inline void pgd_clear(pgd_t * pgdp) { } + +/* + * The following only work if pte_present() is true. + * Undefined behaviour if not.. + */ + +extern inline int pte_read(pte_t pte) { return pte_val(pte) & _PAGE_READ; } +extern inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_WRITE; } +extern inline int pte_exec(pte_t pte) { return pte_val(pte) & _PAGE_READ; } +extern inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_MODIFIED; } +extern inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; } +extern inline int pte_file(pte_t pte) { return pte_val(pte) & _PAGE_FILE; } + +extern inline pte_t pte_wrprotect(pte_t pte) +{ + pte_val(pte) &= ~(_PAGE_WRITE | _PAGE_SILENT_WRITE); + return pte; +} + +extern inline pte_t pte_rdprotect(pte_t pte) +{ + pte_val(pte) &= ~(_PAGE_READ | _PAGE_SILENT_READ); + return pte; +} + +extern inline pte_t pte_exprotect(pte_t pte) +{ + pte_val(pte) &= ~(_PAGE_READ | _PAGE_SILENT_READ); + return pte; +} + +extern inline pte_t pte_mkclean(pte_t pte) +{ + pte_val(pte) &= ~(_PAGE_MODIFIED | _PAGE_SILENT_WRITE); + return pte; +} + +extern inline pte_t pte_mkold(pte_t pte) +{ + pte_val(pte) &= ~(_PAGE_ACCESSED | _PAGE_SILENT_READ); + return pte; +} + +extern 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; +} + +extern inline pte_t pte_mkread(pte_t pte) +{ + pte_val(pte) |= _PAGE_READ; + if (pte_val(pte) & _PAGE_ACCESSED) + pte_val(pte) |= _PAGE_SILENT_READ; + return pte; +} + +extern inline pte_t pte_mkexec(pte_t pte) +{ + pte_val(pte) |= _PAGE_READ; + if (pte_val(pte) & _PAGE_ACCESSED) + pte_val(pte) |= _PAGE_SILENT_READ; + return pte; +} + +extern 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; +} + +extern 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; +} + +/* + * 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. + */ + +extern 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; \ +}) + +extern 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 + */ + +extern 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. + */ + +extern 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_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)) + +/* to find an entry in a page-table-directory */ +extern inline pgd_t * pgd_offset(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 second-level page table.. */ +extern inline pmd_t * pmd_offset(pgd_t * dir, unsigned long address) +{ + return (pmd_t *) dir; +} + +/* 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_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)(__va((x).pte)) >> PAGE_SHIFT) +#define pfn_pte(pfn, prot) __pte((__pa((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 pmd_ERROR(e) \ + printk("%s:%d: bad pmd %p(%08lx).\n", __FILE__, __LINE__, &(e), pmd_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. + */ +extern 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 <asm-generic/pgtable.h> + +/* + * 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) + +#endif /* __ASSEMBLY__ */ +#endif /* _CRIS_PGTABLE_H */ |