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Diffstat (limited to 'include/asm-alpha/pgtable.h')
| -rw-r--r-- | include/asm-alpha/pgtable.h | 423 |
1 files changed, 423 insertions, 0 deletions
diff --git a/include/asm-alpha/pgtable.h b/include/asm-alpha/pgtable.h new file mode 100644 index 000000000..51425af46 --- /dev/null +++ b/include/asm-alpha/pgtable.h @@ -0,0 +1,423 @@ +#ifndef _ALPHA_PGTABLE_H +#define _ALPHA_PGTABLE_H + +/* + * This file contains the functions and defines necessary to modify and use + * the alpha page table tree. + * + * This hopefully works with any standard alpha page-size, as defined + * in <asm/page.h> (currently 8192). + */ + +/* PMD_SHIFT determines the size of the area a second-level page table can map */ +#define PMD_SHIFT (PAGE_SHIFT + (PAGE_SHIFT-3)) +#define PMD_SIZE (1UL << PMD_SHIFT) +#define PMD_MASK (~(PMD_SIZE-1)) + +/* PGDIR_SHIFT determines what a third-level page table entry can map */ +#define PGDIR_SHIFT (PAGE_SHIFT + 2*(PAGE_SHIFT-3)) +#define PGDIR_SIZE (1UL << PGDIR_SHIFT) +#define PGDIR_MASK (~(PGDIR_SIZE-1)) + +/* + * entries per page directory level: the alpha is three-level, with + * all levels having a one-page page table. + * + * The PGD is special: the last entry is reserved for self-mapping. + */ +#define PTRS_PER_PTE (1UL << (PAGE_SHIFT-3)) +#define PTRS_PER_PMD (1UL << (PAGE_SHIFT-3)) +#define PTRS_PER_PGD ((1UL << (PAGE_SHIFT-3))-1) + +/* the no. of pointers that fit on a page: this will go away */ +#define PTRS_PER_PAGE (1UL << (PAGE_SHIFT-3)) + +#define VMALLOC_START 0xFFFFFE0000000000 +#define VMALLOC_VMADDR(x) ((unsigned long)(x)) + +/* + * OSF/1 PAL-code-imposed page table bits + */ +#define _PAGE_VALID 0x0001 +#define _PAGE_FOR 0x0002 /* used for page protection (fault on read) */ +#define _PAGE_FOW 0x0004 /* used for page protection (fault on write) */ +#define _PAGE_FOE 0x0008 /* used for page protection (fault on exec) */ +#define _PAGE_ASM 0x0010 +#define _PAGE_KRE 0x0100 /* xxx - see below on the "accessed" bit */ +#define _PAGE_URE 0x0200 /* xxx */ +#define _PAGE_KWE 0x1000 /* used to do the dirty bit in software */ +#define _PAGE_UWE 0x2000 /* used to do the dirty bit in software */ + +/* .. and these are ours ... */ +#define _PAGE_COW 0x10000 +#define _PAGE_DIRTY 0x20000 +#define _PAGE_ACCESSED 0x40000 + +/* + * NOTE! The "accessed" bit isn't necessarily exact: it can be kept exactly + * by software (use the KRE/URE/KWE/UWE bits appropriately), but I'll fake it. + * Under Linux/AXP, the "accessed" bit just means "read", and I'll just use + * the KRE/URE bits to watch for it. That way we don't need to overload the + * KWE/UWE bits with both handling dirty and accessed. + * + * Note that the kernel uses the accessed bit just to check whether to page + * out a page or not, so it doesn't have to be exact anyway. + */ + +#define __DIRTY_BITS (_PAGE_DIRTY | _PAGE_KWE | _PAGE_UWE) +#define __ACCESS_BITS (_PAGE_ACCESSED | _PAGE_KRE | _PAGE_URE) + +#define _PFN_MASK 0xFFFFFFFF00000000 + +#define _PAGE_TABLE (_PAGE_VALID | __DIRTY_BITS | __ACCESS_BITS) +#define _PAGE_CHG_MASK (_PFN_MASK | __DIRTY_BITS | __ACCESS_BITS) + +/* + * All the normal masks have the "page accessed" bits on, as any time they are used, + * the page is accessed. They are cleared only by the page-out routines + */ +#define PAGE_NONE __pgprot(_PAGE_VALID | __ACCESS_BITS | _PAGE_FOR | _PAGE_FOW | _PAGE_FOE) +#define PAGE_SHARED __pgprot(_PAGE_VALID | __ACCESS_BITS) +#define PAGE_COPY __pgprot(_PAGE_VALID | __ACCESS_BITS | _PAGE_FOW | _PAGE_COW) +#define PAGE_READONLY __pgprot(_PAGE_VALID | __ACCESS_BITS | _PAGE_FOW) +#define PAGE_KERNEL __pgprot(_PAGE_VALID | _PAGE_ASM | _PAGE_KRE | _PAGE_KWE) + +#define _PAGE_NORMAL(x) __pgprot(_PAGE_VALID | __ACCESS_BITS | (x)) + +#define _PAGE_P(x) _PAGE_NORMAL((x) | (((x) & _PAGE_FOW)?0:(_PAGE_FOW | _PAGE_COW))) +#define _PAGE_S(x) _PAGE_NORMAL(x) + +/* + * The hardware can handle write-only mappings, but as the alpha + * architecture does byte-wide writes with a read-modify-write + * sequence, it's not practical to have write-without-read privs. + * Thus the "-w- -> rw-" and "-wx -> rwx" mapping here (and in + * arch/alpha/mm/fault.c) + */ + /* xwr */ +#define __P000 _PAGE_P(_PAGE_FOE | _PAGE_FOW | _PAGE_FOR) +#define __P001 _PAGE_P(_PAGE_FOE | _PAGE_FOW) +#define __P010 _PAGE_P(_PAGE_FOE) +#define __P011 _PAGE_P(_PAGE_FOE) +#define __P100 _PAGE_P(_PAGE_FOW | _PAGE_FOR) +#define __P101 _PAGE_P(_PAGE_FOW) +#define __P110 _PAGE_P(0) +#define __P111 _PAGE_P(0) + +#define __S000 _PAGE_S(_PAGE_FOE | _PAGE_FOW | _PAGE_FOR) +#define __S001 _PAGE_S(_PAGE_FOE | _PAGE_FOW) +#define __S010 _PAGE_S(_PAGE_FOE) +#define __S011 _PAGE_S(_PAGE_FOE) +#define __S100 _PAGE_S(_PAGE_FOW | _PAGE_FOR) +#define __S101 _PAGE_S(_PAGE_FOW) +#define __S110 _PAGE_S(0) +#define __S111 _PAGE_S(0) + +/* + * BAD_PAGETABLE is used when we need a bogus page-table, while + * BAD_PAGE is used for a bogus page. + * + * ZERO_PAGE is a global shared page that is always zero: used + * for zero-mapped memory areas etc.. + */ +extern pte_t __bad_page(void); +extern pmd_t * __bad_pagetable(void); + +extern unsigned long __zero_page(void); + +#define BAD_PAGETABLE __bad_pagetable() +#define BAD_PAGE __bad_page() +#define ZERO_PAGE __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 */ +#define SIZEOF_PTR_LOG2 3 + +/* to find an entry in a page-table */ +#define PAGE_PTR(address) \ + ((unsigned long)(address)>>(PAGE_SHIFT-SIZEOF_PTR_LOG2)&PTR_MASK&~PAGE_MASK) + +extern unsigned long high_memory; + +/* + * Conversion functions: convert a page and protection to a page entry, + * and a page entry and page directory to the page they refer to. + */ +extern inline pte_t mk_pte(unsigned long page, pgprot_t pgprot) +{ pte_t pte; pte_val(pte) = ((page-PAGE_OFFSET) << (32-PAGE_SHIFT)) | pgprot_val(pgprot); return 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; } + +extern inline void pmd_set(pmd_t * pmdp, pte_t * ptep) +{ pmd_val(*pmdp) = _PAGE_TABLE | ((((unsigned long) ptep) - PAGE_OFFSET) << (32-PAGE_SHIFT)); } + +extern inline void pgd_set(pgd_t * pgdp, pmd_t * pmdp) +{ pgd_val(*pgdp) = _PAGE_TABLE | ((((unsigned long) pmdp) - PAGE_OFFSET) << (32-PAGE_SHIFT)); } + +extern inline unsigned long pte_page(pte_t pte) +{ return PAGE_OFFSET + ((pte_val(pte) & _PFN_MASK) >> (32-PAGE_SHIFT)); } + +extern inline unsigned long pmd_page(pmd_t pmd) +{ return PAGE_OFFSET + ((pmd_val(pmd) & _PFN_MASK) >> (32-PAGE_SHIFT)); } + +extern inline unsigned long pgd_page(pgd_t pgd) +{ return PAGE_OFFSET + ((pgd_val(pgd) & _PFN_MASK) >> (32-PAGE_SHIFT)); } + +extern inline int pte_none(pte_t pte) { return !pte_val(pte); } +extern inline int pte_present(pte_t pte) { return pte_val(pte) & _PAGE_VALID; } +extern inline int pte_inuse(pte_t *ptep) { return mem_map[MAP_NR(ptep)] != 1; } +extern inline void pte_clear(pte_t *ptep) { pte_val(*ptep) = 0; } +extern inline void pte_reuse(pte_t * ptep) +{ + if (!(mem_map[MAP_NR(ptep)] & MAP_PAGE_RESERVED)) + mem_map[MAP_NR(ptep)]++; +} + +extern inline int pmd_none(pmd_t pmd) { return !pmd_val(pmd); } +extern inline int pmd_bad(pmd_t pmd) { return (pmd_val(pmd) & ~_PFN_MASK) != _PAGE_TABLE || pmd_page(pmd) > high_memory; } +extern inline int pmd_present(pmd_t pmd) { return pmd_val(pmd) & _PAGE_VALID; } +extern inline int pmd_inuse(pmd_t *pmdp) { return mem_map[MAP_NR(pmdp)] != 1; } +extern inline void pmd_clear(pmd_t * pmdp) { pmd_val(*pmdp) = 0; } +extern inline void pmd_reuse(pmd_t * pmdp) +{ + if (!(mem_map[MAP_NR(pmdp)] & MAP_PAGE_RESERVED)) + mem_map[MAP_NR(pmdp)]++; +} + +extern inline int pgd_none(pgd_t pgd) { return !pgd_val(pgd); } +extern inline int pgd_bad(pgd_t pgd) { return (pgd_val(pgd) & ~_PFN_MASK) != _PAGE_TABLE || pgd_page(pgd) > high_memory; } +extern inline int pgd_present(pgd_t pgd) { return pgd_val(pgd) & _PAGE_VALID; } +extern inline int pgd_inuse(pgd_t *pgdp) { return mem_map[MAP_NR(pgdp)] != 1; } +extern inline void pgd_clear(pgd_t * pgdp) { pgd_val(*pgdp) = 0; } +extern inline void pgd_reuse(pgd_t * pgdp) +{ + if (!(mem_map[MAP_NR(pgdp)] & MAP_PAGE_RESERVED)) + mem_map[MAP_NR(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_FOR); } +extern inline int pte_write(pte_t pte) { return !(pte_val(pte) & _PAGE_FOW); } +extern inline int pte_exec(pte_t pte) { return !(pte_val(pte) & _PAGE_FOE); } +extern inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY; } +extern inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; } +extern inline int pte_cow(pte_t pte) { return pte_val(pte) & _PAGE_COW; } + +extern inline pte_t pte_wrprotect(pte_t pte) { pte_val(pte) |= _PAGE_FOW; return pte; } +extern inline pte_t pte_rdprotect(pte_t pte) { pte_val(pte) |= _PAGE_FOR; return pte; } +extern inline pte_t pte_exprotect(pte_t pte) { pte_val(pte) |= _PAGE_FOE; return pte; } +extern inline pte_t pte_mkclean(pte_t pte) { pte_val(pte) &= ~(__DIRTY_BITS); return pte; } +extern inline pte_t pte_mkold(pte_t pte) { pte_val(pte) &= ~(__ACCESS_BITS); return pte; } +extern inline pte_t pte_uncow(pte_t pte) { pte_val(pte) &= ~_PAGE_COW; return pte; } +extern inline pte_t pte_mkwrite(pte_t pte) { pte_val(pte) &= ~_PAGE_FOW; return pte; } +extern inline pte_t pte_mkread(pte_t pte) { pte_val(pte) &= ~_PAGE_FOR; return pte; } +extern inline pte_t pte_mkexec(pte_t pte) { pte_val(pte) &= ~_PAGE_FOE; return pte; } +extern inline pte_t pte_mkdirty(pte_t pte) { pte_val(pte) |= __DIRTY_BITS; return pte; } +extern inline pte_t pte_mkyoung(pte_t pte) { pte_val(pte) |= __ACCESS_BITS; return pte; } +extern inline pte_t pte_mkcow(pte_t pte) { pte_val(pte) |= _PAGE_COW; return pte; } + +/* + * To set the page-dir. Note the self-mapping in the last entry + * + * Also note that if we update the current process ptbr, we need to + * update the PAL-cached ptbr value as well.. There doesn't seem to + * be any "wrptbr" PAL-insn, but we can do a dummy swpctx to ourself + * instead. + */ +extern inline void SET_PAGE_DIR(struct task_struct * tsk, pgd_t * pgdir) +{ + pgd_val(pgdir[PTRS_PER_PGD]) = pte_val(mk_pte((unsigned long) pgdir, PAGE_KERNEL)); + tsk->tss.ptbr = ((unsigned long) pgdir - PAGE_OFFSET) >> PAGE_SHIFT; + if (tsk == current) + __asm__ __volatile__( + "bis %0,%0,$16\n\t" + "call_pal %1" + : /* no outputs */ + : "r" (&tsk->tss), "i" (PAL_swpctx) + : "$0", "$1", "$16", "$22", "$23", "$24", "$25"); +} + +#define PAGE_DIR_OFFSET(tsk,address) pgd_offset((tsk),(address)) + +/* to find an entry in a page-table-directory. */ +extern inline pgd_t * pgd_offset(struct task_struct * tsk, unsigned long address) +{ + return (pgd_t *) ((tsk->tss.ptbr << PAGE_SHIFT) + PAGE_OFFSET) + + ((address >> PGDIR_SHIFT) & (PTRS_PER_PAGE - 1)); +} + +/* Find an entry in the second-level page table.. */ +extern inline pmd_t * pmd_offset(pgd_t * dir, unsigned long address) +{ + return (pmd_t *) pgd_page(*dir) + ((address >> PMD_SHIFT) & (PTRS_PER_PAGE - 1)); +} + +/* Find an entry in the third-level page table.. */ +extern inline pte_t * pte_offset(pmd_t * dir, unsigned long address) +{ + return (pte_t *) pmd_page(*dir) + ((address >> PAGE_SHIFT) & (PTRS_PER_PAGE - 1)); +} + +/* + * Allocate and free page tables. The xxx_kernel() versions are + * used to allocate a kernel page table - this turns on ASN bits + * if any, and marks the page tables reserved. + */ +extern inline void pte_free_kernel(pte_t * pte) +{ + mem_map[MAP_NR(pte)] = 1; + free_page((unsigned long) pte); +} + +extern inline pte_t * pte_alloc_kernel(pmd_t *pmd, unsigned long address) +{ + address = (address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1); + if (pmd_none(*pmd)) { + pte_t *page = (pte_t *) get_free_page(GFP_KERNEL); + if (pmd_none(*pmd)) { + if (page) { + pmd_set(pmd, page); + mem_map[MAP_NR(page)] = MAP_PAGE_RESERVED; + return page + address; + } + pmd_set(pmd, (pte_t *) BAD_PAGETABLE); + return NULL; + } + free_page((unsigned long) page); + } + if (pmd_bad(*pmd)) { + printk("Bad pmd in pte_alloc: %08lx\n", pmd_val(*pmd)); + pmd_set(pmd, (pte_t *) BAD_PAGETABLE); + return NULL; + } + return (pte_t *) pmd_page(*pmd) + address; +} + +extern inline void pmd_free_kernel(pmd_t * pmd) +{ + mem_map[MAP_NR(pmd)] = 1; + free_page((unsigned long) pmd); +} + +extern inline pmd_t * pmd_alloc_kernel(pgd_t *pgd, unsigned long address) +{ + address = (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1); + if (pgd_none(*pgd)) { + pmd_t *page = (pmd_t *) get_free_page(GFP_KERNEL); + if (pgd_none(*pgd)) { + if (page) { + pgd_set(pgd, page); + mem_map[MAP_NR(page)] = MAP_PAGE_RESERVED; + return page + address; + } + pgd_set(pgd, BAD_PAGETABLE); + return NULL; + } + free_page((unsigned long) page); + } + if (pgd_bad(*pgd)) { + printk("Bad pgd in pmd_alloc: %08lx\n", pgd_val(*pgd)); + pgd_set(pgd, BAD_PAGETABLE); + return NULL; + } + return (pmd_t *) pgd_page(*pgd) + address; +} + +extern inline void pte_free(pte_t * pte) +{ + free_page((unsigned long) pte); +} + +extern inline pte_t * pte_alloc(pmd_t *pmd, unsigned long address) +{ + address = (address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1); + if (pmd_none(*pmd)) { + pte_t *page = (pte_t *) get_free_page(GFP_KERNEL); + if (pmd_none(*pmd)) { + if (page) { + pmd_set(pmd, page); + return page + address; + } + pmd_set(pmd, (pte_t *) BAD_PAGETABLE); + return NULL; + } + free_page((unsigned long) page); + } + if (pmd_bad(*pmd)) { + printk("Bad pmd in pte_alloc: %08lx\n", pmd_val(*pmd)); + pmd_set(pmd, (pte_t *) BAD_PAGETABLE); + return NULL; + } + return (pte_t *) pmd_page(*pmd) + address; +} + +extern inline void pmd_free(pmd_t * pmd) +{ + free_page((unsigned long) pmd); +} + +extern inline pmd_t * pmd_alloc(pgd_t *pgd, unsigned long address) +{ + address = (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1); + if (pgd_none(*pgd)) { + pmd_t *page = (pmd_t *) get_free_page(GFP_KERNEL); + if (pgd_none(*pgd)) { + if (page) { + pgd_set(pgd, page); + return page + address; + } + pgd_set(pgd, BAD_PAGETABLE); + return NULL; + } + free_page((unsigned long) page); + } + if (pgd_bad(*pgd)) { + printk("Bad pgd in pmd_alloc: %08lx\n", pgd_val(*pgd)); + pgd_set(pgd, BAD_PAGETABLE); + return NULL; + } + return (pmd_t *) pgd_page(*pgd) + address; +} + +extern inline void pgd_free(pgd_t * pgd) +{ + free_page((unsigned long) pgd); +} + +extern inline pgd_t * pgd_alloc(void) +{ + return (pgd_t *) get_free_page(GFP_KERNEL); +} + +extern pgd_t swapper_pg_dir[1024]; + +/* + * The alpha doesn't have any external MMU info: the kernel page + * tables contain all the necessary information. + */ +extern inline void update_mmu_cache(struct vm_area_struct * vma, + unsigned long address, pte_t pte) +{ +} + +/* + * Non-present pages: high 24 bits are offset, next 8 bits type, + * low 32 bits zero.. + */ +extern inline pte_t mk_swap_pte(unsigned long type, unsigned long offset) +{ pte_t pte; pte_val(pte) = (type << 32) | (offset << 40); return pte; } + +#define SWP_TYPE(entry) (((entry) >> 32) & 0xff) +#define SWP_OFFSET(entry) ((entry) >> 40) +#define SWP_ENTRY(type,offset) pte_val(mk_swap_pte((type),(offset))) + +#endif /* _ALPHA_PGTABLE_H */ |