/* * 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 #include 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_dcache_page(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) (virt_to_page(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<>(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; } #define PTE_INIT(x) pte_clear(x) 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)<virtual) #define pte_page(x) (mem_map+(unsigned long)((pte_val(pte) >> PAGE_SHIFT))) #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 }) #include #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 */