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Diffstat (limited to 'include/asm-s390/pgtable.h')
| -rw-r--r-- | include/asm-s390/pgtable.h | 418 |
1 files changed, 418 insertions, 0 deletions
diff --git a/include/asm-s390/pgtable.h b/include/asm-s390/pgtable.h new file mode 100644 index 000000000..f5f854749 --- /dev/null +++ b/include/asm-s390/pgtable.h @@ -0,0 +1,418 @@ +/* + * include/asm-s390/pgtable.h + * + * S390 version + * Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation + * Author(s): Hartmut Penner + * + * Derived from "include/asm-i386/pgtable.h" + */ + +#ifndef _ASM_S390_PGTABLE_H +#define _ASM_S390_PGTABLE_H + +/* + * The Linux memory management assumes a three-level page table setup. On + * the S390, we use that, but "fold" the mid level into the top-level page + * table, so that we physically have the same two-level page table as the + * S390 mmu expects. + * + * This file contains the functions and defines necessary to modify and use + * the S390 page table tree. + */ +#ifndef __ASSEMBLY__ +#include <asm/processor.h> +#include <linux/tasks.h> + +extern pgd_t swapper_pg_dir[] __attribute__ ((aligned (4096))); + +/* Caches aren't brain-dead on S390. */ +#define flush_cache_all() do { } while (0) +#define flush_cache_mm(mm) do { } while (0) +#define flush_cache_range(mm, start, end) do { } while (0) +#define flush_cache_page(vma, vmaddr) do { } while (0) +#define flush_page_to_ram(page) do { } while (0) +#define flush_icache_range(start, end) do { } while (0) +#define flush_icache_page(vma,pg) do { } while (0) + +/* + * ZERO_PAGE is a global shared page that is always zero: used + * for zero-mapped memory areas etc.. + */ +extern unsigned long empty_zero_page[1024]; +#define ZERO_PAGE(vaddr) (mem_map + MAP_NR(empty_zero_page)) +#endif /* !__ASSEMBLY__ */ + +/* Certain architectures need to do special things when PTEs + * within a page table are directly modified. Thus, the following + * hook is made available. + */ +#define set_pte(pteptr, pteval) ((*(pteptr)) = (pteval)) + +/* PMD_SHIFT determines the size of the area a second-level page table can map */ +#define PMD_SHIFT 22 +#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 22 +#define PGDIR_SIZE (1UL << PGDIR_SHIFT) +#define PGDIR_MASK (~(PGDIR_SIZE-1)) + +/* + * entries per page directory level: the S390 is two-level, so + * we don't really have any PMD directory physically. + * for S390 segment-table entries are combined to one PGD + * that leads to 1024 pte per pgd + */ +#define PTRS_PER_PTE 1024 +#define PTRS_PER_PMD 1 +#define PTRS_PER_PGD 512 + + +/* + * pgd entries used up by user/kernel: + */ +#define USER_PTRS_PER_PGD 512 +#define USER_PGD_PTRS 512 +#define KERNEL_PGD_PTRS 512 +#define FIRST_USER_PGD_NR 0 + +#define pte_ERROR(e) \ + printk("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e)) +#define pmd_ERROR(e) \ + printk("%s:%d: bad pmd %08lx.\n", __FILE__, __LINE__, pmd_val(e)) +#define pgd_ERROR(e) \ + printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e)) + +#ifndef __ASSEMBLY__ +/* Just any arbitrary offset to the start of the vmalloc VM area: the + * current 8MB value just means that there will be a 8MB "hole" after the + * physical memory until the kernel virtual memory starts. That means that + * any out-of-bounds memory accesses will hopefully be caught. + * The vmalloc() routines leaves a hole of 4kB between each vmalloced + * area for the same reason. ;) + */ +#define VMALLOC_OFFSET (8*1024*1024) +#define VMALLOC_START (((unsigned long) high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1)) +#define VMALLOC_VMADDR(x) ((unsigned long)(x)) +#define VMALLOC_END (0x7fffffffL) + + +/* + * A pagetable entry of S390 has following format: + * + * | PFRA | | OS | + * 0 0IP0 + * 00000000001111111111222222222233 + * 01234567890123456789012345678901 + * + * I Page-Invalid Bit: Page is not available for address-translation + * P Page-Protection Bit: Store access not possible for page + */ + +/* + * A segmenttable entry of S390 has following format: + * + * | P-table origin | |PTL + * 0 IC + * 00000000001111111111222222222233 + * 01234567890123456789012345678901 + * + * I Segment-Invalid Bit: Segment is not available for address-translation + * C Common-Segment Bit: Segment is not private (PoP 3-30) + * PTL Page-Table-Length: Length of Page-table (PTL+1*16 entries -> up to 256 entries) + */ + +/* + * The segmenttable origin of S390 has following format: + * + * |S-table origin | | STL | + * X **GPS + * 00000000001111111111222222222233 + * 01234567890123456789012345678901 + * + * X Space-Switch event: + * G Segment-Invalid Bit: * + * P Private-Space Bit: Segment is not private (PoP 3-30) + * S Storage-Alteration: + * STL Segment-Table-Length: Length of Page-table (STL+1*16 entries -> up to 2048 entries) + */ + +#define _PAGE_PRESENT 0x001 /* Software */ +#define _PAGE_ACCESSED 0x002 /* Software accessed */ +#define _PAGE_DIRTY 0x004 /* Software dirty */ +#define _PAGE_RO 0x200 /* HW read-only */ +#define _PAGE_INVALID 0x400 /* HW invalid */ + +#define _PAGE_TABLE_LEN 0xf /* only full page-tables */ +#define _PAGE_TABLE_COM 0x10 /* common page-table */ +#define _PAGE_TABLE_INV 0x20 /* invalid page-table */ +#define _SEG_PRESENT 0x001 /* Software (overlap with PTL) */ + +#define _USER_SEG_TABLE_LEN 0x7f /* user-segment-table up to 2 GB */ +#define _KERNEL_SEG_TABLE_LEN 0x7f /* kernel-segment-table up to 2 GB */ + +/* + * User and Kernel pagetables are identical + */ + +#define _PAGE_TABLE (_PAGE_TABLE_LEN ) +#define _KERNPG_TABLE (_PAGE_TABLE_LEN ) + +/* + * The Kernel segment-tables includes the User segment-table + */ + +#define _SEGMENT_TABLE (_USER_SEG_TABLE_LEN|0x80000000) +#define _KERNSEG_TABLE (_KERNEL_SEG_TABLE_LEN) +/* + * No mapping available + */ +#define PAGE_NONE __pgprot(_PAGE_INVALID ) + +#define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED) +#define PAGE_COPY __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_RO) +#define PAGE_READONLY __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_RO) +#define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY) + +/* + * The S390 can't do page protection for execute, and considers that the same are read. + * Also, write permissions imply read permissions. This is the closest we can get.. + */ +#define __P000 PAGE_NONE +#define __P001 PAGE_READONLY +#define __P010 PAGE_COPY +#define __P011 PAGE_COPY +#define __P100 PAGE_READONLY +#define __P101 PAGE_READONLY +#define __P110 PAGE_COPY +#define __P111 PAGE_COPY + +#define __S000 PAGE_NONE +#define __S001 PAGE_READONLY +#define __S010 PAGE_SHARED +#define __S011 PAGE_SHARED +#define __S100 PAGE_READONLY +#define __S101 PAGE_READONLY +#define __S110 PAGE_SHARED +#define __S111 PAGE_SHARED + +/* + * Define this if things work differently on an i386 and an i486: + * it will (on an i486) warn about kernel memory accesses that are + * done without a 'verify_area(VERIFY_WRITE,..)' + * + * Kernel and User memory-access are done equal, so we don't need verify + */ +#undef TEST_VERIFY_AREA + +/* page table for 0-4MB for everybody */ +extern unsigned long pg0[1024]; + +/* 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) + + + +/* + * CR 7 (SPST) and cr 13 (HPST) are set to the user pgdir. + * Kernel is running in its own, disjunct address space, + * running in primary address space. + * Copy to/from user is done via access register mode with + * access registers set to 0 or 1. For that purpose we need + * set up CR 7 with the user pgd. + * + */ + +#define SET_PAGE_DIR(tsk,pgdir) \ +do { \ + unsigned long __pgdir = (__pa(pgdir) & PAGE_MASK ) | _SEGMENT_TABLE; \ + (tsk)->thread.user_seg = __pgdir; \ + if ((tsk) == current) { \ + __asm__ __volatile__("lctl 7,7,%0": :"m" (__pgdir)); \ + __asm__ __volatile__("lctl 13,13,%0": :"m" (__pgdir)); \ + } \ +} while (0) + +/* + * CR 7 (SPST) and cr 13 (HPST) are set to the user pgdir. + * Kernel is running in its own, disjunct address space, + * running in primary address space. + * Copy to/from user is done via access register mode with + * access registers set to 0 or 1. For that purpose we need + * set up CR 7 with the user pgd. + * + */ + +#define SET_PAGE_DIR(tsk,pgdir) \ +do { \ + unsigned long __pgdir = (__pa(pgdir) & PAGE_MASK ) | _SEGMENT_TABLE; \ + (tsk)->thread.user_seg = __pgdir; \ + if ((tsk) == current) { \ + __asm__ __volatile__("lctl 7,7,%0": :"m" (__pgdir)); \ + __asm__ __volatile__("lctl 13,13,%0": :"m" (__pgdir)); \ + } \ +} while (0) + + +extern inline int pte_none(pte_t pte) { return ((pte_val(pte) & (_PAGE_INVALID | _PAGE_RO)) == _PAGE_INVALID); } +extern inline int pte_present(pte_t pte) { return pte_val(pte) & _PAGE_PRESENT; } +extern inline void pte_clear(pte_t *ptep) { pte_val(*ptep) = _PAGE_INVALID; } +extern inline int pte_pagenr(pte_t pte) { return ((unsigned long)((pte_val(pte) >> PAGE_SHIFT))); } + +extern inline int pmd_none(pmd_t pmd) { return pmd_val(pmd) & _PAGE_TABLE_INV; } +extern inline int pmd_bad(pmd_t pmd) { return (pmd_val(pmd) == 0); } +extern inline int pmd_present(pmd_t pmd) { return pmd_val(pmd) & _SEG_PRESENT; } +extern inline void pmd_clear(pmd_t * pmdp) { + pmd_val(pmdp[0]) = _PAGE_TABLE_INV; + pmd_val(pmdp[1]) = _PAGE_TABLE_INV; + pmd_val(pmdp[2]) = _PAGE_TABLE_INV; + pmd_val(pmdp[3]) = _PAGE_TABLE_INV; + } + +/* + * 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_write(pte_t pte) { return !(pte_val(pte) & _PAGE_RO); } +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; } + +/* who needs that +extern inline int pte_read(pte_t pte) { return !(pte_val(pte) & _PAGE_INVALID); } +extern inline int pte_exec(pte_t pte) { return !(pte_val(pte) & _PAGE_INVALID); } +extern inline pte_t pte_rdprotect(pte_t pte) { pte_val(pte) |= _PAGE_INVALID; return pte; } +extern inline pte_t pte_exprotect(pte_t pte) { pte_val(pte) |= _PAGE_INVALID; return pte; } +extern inline pte_t pte_mkread(pte_t pte) { pte_val(pte) &= _PAGE_INVALID; return pte; } +extern inline pte_t pte_mkexec(pte_t pte) { pte_val(pte) &= _PAGE_INVALID; return pte; } +*/ + +extern inline pte_t pte_wrprotect(pte_t pte) { pte_val(pte) |= _PAGE_RO; return pte; } +extern inline pte_t pte_mkwrite(pte_t pte) { pte_val(pte) &= ~_PAGE_RO ; return pte; } + +extern inline pte_t pte_mkclean(pte_t pte) { pte_val(pte) &= ~_PAGE_DIRTY; return pte; } +extern inline pte_t pte_mkdirty(pte_t pte) { pte_val(pte) |= _PAGE_DIRTY; return pte; } + +extern inline pte_t pte_mkold(pte_t pte) { pte_val(pte) &= ~_PAGE_ACCESSED; return pte; } +extern 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. + */ +#define mk_pte(page, pgprot) \ +({ pte_t __pte; pte_val(__pte) = __pa(((page)-mem_map)<<PAGE_SHIFT) + pgprot_val(pgprot); __pte; }) + +/* This takes a physical page address that is used by the remapping functions */ +#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_MASK) | pgprot_val(newprot); return pte; } + +#define page_address(page) \ +({ if (!(page)->virtual) BUG(); (page)->virtual; }) +#define pte_page(x) (mem_map+pte_pagenr(x)) + +#define pmd_page(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) + +/* 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(pmd, address) \ +((pte_t *) (pmd_page(*pmd) + ((address>>10) & ((PTRS_PER_PTE-1)<<2)))) + + +/* We don't use pmd cache, so these are dummy routines */ +extern __inline__ pmd_t *get_pmd_fast(void) +{ + return (pmd_t *)0; +} + +extern __inline__ void free_pmd_fast(pmd_t *pmd) +{ +} + +extern __inline__ void free_pmd_slow(pmd_t *pmd) +{ +} + +extern void __handle_bad_pmd(pmd_t *pmd); +extern void __handle_bad_pmd_kernel(pmd_t *pmd); + +/* + * The S390 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) +{ +} + +/* + * a page-table entry has only 19 bit for offset and 7 bit for type + * if bits 0, 20 or 23 are set, a translation specification exceptions occures, and it's + * hard to find out the failing address + * therefor, we zero out this bits + */ + +#define SWP_TYPE(entry) (((entry).val >> 1) & 0x3f) +#define SWP_OFFSET(entry) (((entry).val >> 12) & 0x7FFFF ) +#define SWP_ENTRY(type,offset) ((swp_entry_t) { (((type) << 1) | \ + ((offset) << 12) | \ + _PAGE_INVALID | _PAGE_RO) \ + & 0x7ffff6fe }) + +#define pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) +#define swp_entry_to_pte(x) ((pte_t) { (x).val }) + +#define module_map vmalloc +#define module_unmap vfree + +#endif /* !__ASSEMBLY__ */ + +/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */ +#define PageSkip(page) (0) +#define kern_addr_valid(addr) (1) + +#endif /* _S390_PAGE_H */ + |