/* * include/asm-s390/pgtable.h * * S390 version * Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation * Author(s): Hartmut Penner (hp@de.ibm.com) * Ulrich Weigand (weigand@de.ibm.com) * Martin Schwidefsky (schwidefsky@de.ibm.com) * * 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. For * s390 31 bit we "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 in 31 bit mode. For s390 64 bit we use three of the five levels * the hardware provides (region first and region second tables are not * used). * * The "pgd_xxx()" functions 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) * * This file contains the functions and defines necessary to modify and use * the S390 page table tree. */ #ifndef __ASSEMBLY__ #include #include #include #include #include extern pgd_t swapper_pg_dir[] __attribute__ ((aligned (4096))); extern void paging_init(void); extern void vmem_map_init(void); extern void fault_init(void); /* * The S390 doesn't have any external MMU info: the kernel page * tables contain all the necessary information. */ #define update_mmu_cache(vma, address, ptep) 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; extern unsigned long zero_page_mask; #define ZERO_PAGE(vaddr) \ (virt_to_page((void *)(empty_zero_page + \ (((unsigned long)(vaddr)) &zero_page_mask)))) #define is_zero_pfn is_zero_pfn static inline int is_zero_pfn(unsigned long pfn) { extern unsigned long zero_pfn; unsigned long offset_from_zero_pfn = pfn - zero_pfn; return offset_from_zero_pfn <= (zero_page_mask >> PAGE_SHIFT); } #define my_zero_pfn(addr) page_to_pfn(ZERO_PAGE(addr)) #endif /* !__ASSEMBLY__ */ /* * PMD_SHIFT determines the size of the area a second-level page * table can map * PGDIR_SHIFT determines what a third-level page table entry can map */ #ifndef __s390x__ # define PMD_SHIFT 20 # define PUD_SHIFT 20 # define PGDIR_SHIFT 20 #else /* __s390x__ */ # define PMD_SHIFT 20 # define PUD_SHIFT 31 # define PGDIR_SHIFT 42 #endif /* __s390x__ */ #define PMD_SIZE (1UL << PMD_SHIFT) #define PMD_MASK (~(PMD_SIZE-1)) #define PUD_SIZE (1UL << PUD_SHIFT) #define PUD_MASK (~(PUD_SIZE-1)) #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 256 #ifndef __s390x__ #define PTRS_PER_PMD 1 #define PTRS_PER_PUD 1 #else /* __s390x__ */ #define PTRS_PER_PMD 2048 #define PTRS_PER_PUD 2048 #endif /* __s390x__ */ #define PTRS_PER_PGD 2048 #define FIRST_USER_ADDRESS 0 #define pte_ERROR(e) \ printk("%s:%d: bad pte %p.\n", __FILE__, __LINE__, (void *) pte_val(e)) #define pmd_ERROR(e) \ printk("%s:%d: bad pmd %p.\n", __FILE__, __LINE__, (void *) pmd_val(e)) #define pud_ERROR(e) \ printk("%s:%d: bad pud %p.\n", __FILE__, __LINE__, (void *) pud_val(e)) #define pgd_ERROR(e) \ printk("%s:%d: bad pgd %p.\n", __FILE__, __LINE__, (void *) pgd_val(e)) #ifndef __ASSEMBLY__ /* * The vmalloc area will always be on the topmost area of the kernel * mapping. We reserve 96MB (31bit) / 128GB (64bit) for vmalloc, * which should be enough for any sane case. * By putting vmalloc at the top, we maximise the gap between physical * memory and vmalloc to catch misplaced memory accesses. As a side * effect, this also makes sure that 64 bit module code cannot be used * as system call address. */ extern unsigned long VMALLOC_START; #ifndef __s390x__ #define VMALLOC_SIZE (96UL << 20) #define VMALLOC_END 0x7e000000UL #define VMEM_MAP_END 0x80000000UL #else /* __s390x__ */ #define VMALLOC_SIZE (128UL << 30) #define VMALLOC_END 0x3e000000000UL #define VMEM_MAP_END 0x40000000000UL #endif /* __s390x__ */ /* * VMEM_MAX_PHYS is the highest physical address that can be added to the 1:1 * mapping. This needs to be calculated at compile time since the size of the * VMEM_MAP is static but the size of struct page can change. */ #define VMEM_MAX_PAGES ((VMEM_MAP_END - VMALLOC_END) / sizeof(struct page)) #define VMEM_MAX_PFN min(VMALLOC_START >> PAGE_SHIFT, VMEM_MAX_PAGES) #define VMEM_MAX_PHYS ((VMEM_MAX_PFN << PAGE_SHIFT) & ~((16 << 20) - 1)) #define vmemmap ((struct page *) VMALLOC_END) /* * A 31 bit 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 31 bit 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: Page-table length (PTL+1*16 entries -> up to 256) * * The 31 bit 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: Segment-table length (STL+1*16 entries -> up to 2048) * * A 64 bit pagetable entry of S390 has following format: * | PFRA |0IPC| OS | * 0000000000111111111122222222223333333333444444444455555555556666 * 0123456789012345678901234567890123456789012345678901234567890123 * * I Page-Invalid Bit: Page is not available for address-translation * P Page-Protection Bit: Store access not possible for page * C Change-bit override: HW is not required to set change bit * * A 64 bit segmenttable entry of S390 has following format: * | P-table origin | TT * 0000000000111111111122222222223333333333444444444455555555556666 * 0123456789012345678901234567890123456789012345678901234567890123 * * I Segment-Invalid Bit: Segment is not available for address-translation * C Common-Segment Bit: Segment is not private (PoP 3-30) * P Page-Protection Bit: Store access not possible for page * TT Type 00 * * A 64 bit region table entry of S390 has following format: * | S-table origin | TF TTTL * 0000000000111111111122222222223333333333444444444455555555556666 * 0123456789012345678901234567890123456789012345678901234567890123 * * I Segment-Invalid Bit: Segment is not available for address-translation * TT Type 01 * TF * TL Table length * * The 64 bit regiontable origin of S390 has following format: * | region table origon | DTTL * 0000000000111111111122222222223333333333444444444455555555556666 * 0123456789012345678901234567890123456789012345678901234567890123 * * X Space-Switch event: * G Segment-Invalid Bit: * P Private-Space Bit: * S Storage-Alteration: * R Real space * TL Table-Length: * * A storage key has the following format: * | ACC |F|R|C|0| * 0 3 4 5 6 7 * ACC: access key * F : fetch protection bit * R : referenced bit * C : changed bit */ /* Hardware bits in the page table entry */ #define _PAGE_CO 0x100 /* HW Change-bit override */ #define _PAGE_RO 0x200 /* HW read-only bit */ #define _PAGE_INVALID 0x400 /* HW invalid bit */ /* Software bits in the page table entry */ #define _PAGE_SWT 0x001 /* SW pte type bit t */ #define _PAGE_SWX 0x002 /* SW pte type bit x */ #define _PAGE_SPECIAL 0x004 /* SW associated with special page */ #define __HAVE_ARCH_PTE_SPECIAL /* Set of bits not changed in pte_modify */ #define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_SPECIAL) /* Six different types of pages. */ #define _PAGE_TYPE_EMPTY 0x400 #define _PAGE_TYPE_NONE 0x401 #define _PAGE_TYPE_SWAP 0x403 #define _PAGE_TYPE_FILE 0x601 /* bit 0x002 is used for offset !! */ #define _PAGE_TYPE_RO 0x200 #define _PAGE_TYPE_RW 0x000 /* * Only four types for huge pages, using the invalid bit and protection bit * of a segment table entry. */ #define _HPAGE_TYPE_EMPTY 0x020 /* _SEGMENT_ENTRY_INV */ #define _HPAGE_TYPE_NONE 0x220 #define _HPAGE_TYPE_RO 0x200 /* _SEGMENT_ENTRY_RO */ #define _HPAGE_TYPE_RW 0x000 /* * PTE type bits are rather complicated. handle_pte_fault uses pte_present, * pte_none and pte_file to find out the pte type WITHOUT holding the page * table lock. ptep_clear_flush on the other hand uses ptep_clear_flush to * invalidate a given pte. ipte sets the hw invalid bit and clears all tlbs * for the page. The page table entry is set to _PAGE_TYPE_EMPTY afterwards. * This change is done while holding the lock, but the intermediate step * of a previously valid pte with the hw invalid bit set can be observed by * handle_pte_fault. That makes it necessary that all valid pte types with * the hw invalid bit set must be distinguishable from the four pte types * empty, none, swap and file. * * irxt ipte irxt * _PAGE_TYPE_EMPTY 1000 -> 1000 * _PAGE_TYPE_NONE 1001 -> 1001 * _PAGE_TYPE_SWAP 1011 -> 1011 * _PAGE_TYPE_FILE 11?1 -> 11?1 * _PAGE_TYPE_RO 0100 -> 1100 * _PAGE_TYPE_RW 0000 -> 1000 * * pte_none is true for bits combinations 1000, 1010, 1100, 1110 * pte_present is true for bits combinations 0000, 0010, 0100, 0110, 1001 * pte_file is true for bits combinations 1101, 1111 * swap pte is 1011 and 0001, 0011, 0101, 0111 are invalid. */ /* Page status table bits for virtualization */ #define RCP_PCL_BIT 55 #define RCP_HR_BIT 54 #define RCP_HC_BIT 53 #define RCP_GR_BIT 50 #define RCP_GC_BIT 49 /* User dirty bit for KVM's migration feature */ #define KVM_UD_BIT 47 #ifndef __s390x__ /* Bits in the segment table address-space-control-element */ #define _ASCE_SPACE_SWITCH 0x80000000UL /* space switch event */ #define _ASCE_ORIGIN_MASK 0x7ffff000UL /* segment table origin */ #define _ASCE_PRIVATE_SPACE 0x100 /* private space control */ #define _ASCE_ALT_EVENT 0x80 /* storage alteration event control */ #define _ASCE_TABLE_LENGTH 0x7f /* 128 x 64 entries = 8k */ /* Bits in the segment table entry */ #define _SEGMENT_ENTRY_ORIGIN 0x7fffffc0UL /* page table origin */ #define _SEGMENT_ENTRY_RO 0x200 /* page protection bit */ #define _SEGMENT_ENTRY_INV 0x20 /* invalid segment table entry */ #define _SEGMENT_ENTRY_COMMON 0x10 /* common segment bit */ #define _SEGMENT_ENTRY_PTL 0x0f /* page table length */ #define _SEGMENT_ENTRY (_SEGMENT_ENTRY_PTL) #define _SEGMENT_ENTRY_EMPTY (_SEGMENT_ENTRY_INV) #else /* __s390x__ */ /* Bits in the segment/region table address-space-control-element */ #define _ASCE_ORIGIN ~0xfffUL/* segment table origin */ #define _ASCE_PRIVATE_SPACE 0x100 /* private space control */ #define _ASCE_ALT_EVENT 0x80 /* storage alteration event control */ #define _ASCE_SPACE_SWITCH 0x40 /* space switch event */ #define _ASCE_REAL_SPACE 0x20 /* real space control */ #define _ASCE_TYPE_MASK 0x0c /* asce table type mask */ #define _ASCE_TYPE_REGION1 0x0c /* region first table type */ #define _ASCE_TYPE_REGION2 0x08 /* region second table type */ #define _ASCE_TYPE_REGION3 0x04 /* region third table type */ #define _ASCE_TYPE_SEGMENT 0x00 /* segment table type */ #define _ASCE_TABLE_LENGTH 0x03 /* region table length */ /* Bits in the region table entry */ #define _REGION_ENTRY_ORIGIN ~0xfffUL/* region/segment table origin */ #define _REGION_ENTRY_INV 0x20 /* invalid region table entry */ #define _REGION_ENTRY_TYPE_MASK 0x0c /* region/segment table type mask */ #define _REGION_ENTRY_TYPE_R1 0x0c /* region first table type */ #define _REGION_ENTRY_TYPE_R2 0x08 /* region second table type */ #define _REGION_ENTRY_TYPE_R3 0x04 /* region third table type */ #define _REGION_ENTRY_LENGTH 0x03 /* region third length */ #define _REGION1_ENTRY (_REGION_ENTRY_TYPE_R1 | _REGION_ENTRY_LENGTH) #define _REGION1_ENTRY_EMPTY (_REGION_ENTRY_TYPE_R1 | _REGION_ENTRY_INV) #define _REGION2_ENTRY (_REGION_ENTRY_TYPE_R2 | _REGION_ENTRY_LENGTH) #define _REGION2_ENTRY_EMPTY (_REGION_ENTRY_TYPE_R2 | _REGION_ENTRY_INV) #define _REGION3_ENTRY (_REGION_ENTRY_TYPE_R3 | _REGION_ENTRY_LENGTH) #define _REGION3_ENTRY_EMPTY (_REGION_ENTRY_TYPE_R3 | _REGION_ENTRY_INV) /* Bits in the segment table entry */ #define _SEGMENT_ENTRY_ORIGIN ~0x7ffUL/* segment table origin */ #define _SEGMENT_ENTRY_RO 0x200 /* page protection bit */ #define _SEGMENT_ENTRY_INV 0x20 /* invalid segment table entry */ #define _SEGMENT_ENTRY (0) #define _SEGMENT_ENTRY_EMPTY (_SEGMENT_ENTRY_INV) #define _SEGMENT_ENTRY_LARGE 0x400 /* STE-format control, large page */ #define _SEGMENT_ENTRY_CO 0x100 /* change-recording override */ #endif /* __s390x__ */ /* * A user page table pointer has the space-switch-event bit, the * private-space-control bit and the storage-alteration-event-control * bit set. A kernel page table pointer doesn't need them. */ #define _ASCE_USER_BITS (_ASCE_SPACE_SWITCH | _ASCE_PRIVATE_SPACE | \ _ASCE_ALT_EVENT) /* * Page protection definitions. */ #define PAGE_NONE __pgprot(_PAGE_TYPE_NONE) #define PAGE_RO __pgprot(_PAGE_TYPE_RO) #define PAGE_RW __pgprot(_PAGE_TYPE_RW) #define PAGE_KERNEL PAGE_RW #define PAGE_COPY PAGE_RO /* * On s390 the page table entry has an invalid bit and a read-only bit. * Read permission implies execute permission and write permission * implies read permission. */ /*xwr*/ #define __P000 PAGE_NONE #define __P001 PAGE_RO #define __P010 PAGE_RO #define __P011 PAGE_RO #define __P100 PAGE_RO #define __P101 PAGE_RO #define __P110 PAGE_RO #define __P111 PAGE_RO #define __S000 PAGE_NONE #define __S001 PAGE_RO #define __S010 PAGE_RW #define __S011 PAGE_RW #define __S100 PAGE_RO #define __S101 PAGE_RO #define __S110 PAGE_RW #define __S111 PAGE_RW /* * Certain architectures need to do special things when PTEs * within a page table are directly modified. Thus, the following * hook is made available. */ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t entry) { *ptep = entry; } /* * pgd/pmd/pte query functions */ #ifndef __s390x__ static inline int pgd_present(pgd_t pgd) { return 1; } static inline int pgd_none(pgd_t pgd) { return 0; } static inline int pgd_bad(pgd_t pgd) { return 0; } static inline int pud_present(pud_t pud) { return 1; } static inline int pud_none(pud_t pud) { return 0; } static inline int pud_bad(pud_t pud) { return 0; } #else /* __s390x__ */ static inline int pgd_present(pgd_t pgd) { if ((pgd_val(pgd) & _REGION_ENTRY_TYPE_MASK) < _REGION_ENTRY_TYPE_R2) return 1; return (pgd_val(pgd) & _REGION_ENTRY_ORIGIN) != 0UL; } static inline int pgd_none(pgd_t pgd) { if ((pgd_val(pgd) & _REGION_ENTRY_TYPE_MASK) < _REGION_ENTRY_TYPE_R2) return 0; return (pgd_val(pgd) & _REGION_ENTRY_INV) != 0UL; } static inline int pgd_bad(pgd_t pgd) { /* * With dynamic page table levels the pgd can be a region table * entry or a segment table entry. Check for the bit that are * invalid for either table entry. */ unsigned long mask = ~_SEGMENT_ENTRY_ORIGIN & ~_REGION_ENTRY_INV & ~_REGION_ENTRY_TYPE_MASK & ~_REGION_ENTRY_LENGTH; return (pgd_val(pgd) & mask) != 0; } static inline int pud_present(pud_t pud) { if ((pud_val(pud) & _REGION_ENTRY_TYPE_MASK) < _REGION_ENTRY_TYPE_R3) return 1; return (pud_val(pud) & _REGION_ENTRY_ORIGIN) != 0UL; } static inline int pud_none(pud_t pud) { if ((pud_val(pud) & _REGION_ENTRY_TYPE_MASK) < _REGION_ENTRY_TYPE_R3) return 0; return (pud_val(pud) & _REGION_ENTRY_INV) != 0UL; } static inline int pud_bad(pud_t pud) { /* * With dynamic page table levels the pud can be a region table * entry or a segment table entry. Check for the bit that are * invalid for either table entry. */ unsigned long mask = ~_SEGMENT_ENTRY_ORIGIN & ~_REGION_ENTRY_INV & ~_REGION_ENTRY_TYPE_MASK & ~_REGION_ENTRY_LENGTH; return (pud_val(pud) & mask) != 0; } #endif /* __s390x__ */ static inline int pmd_present(pmd_t pmd) { return (pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN) != 0UL; } static inline int pmd_none(pmd_t pmd) { return (pmd_val(pmd) & _SEGMENT_ENTRY_INV) != 0UL; } static inline int pmd_bad(pmd_t pmd) { unsigned long mask = ~_SEGMENT_ENTRY_ORIGIN & ~_SEGMENT_ENTRY_INV; return (pmd_val(pmd) & mask) != _SEGMENT_ENTRY; } static inline int pte_none(pte_t pte) { return (pte_val(pte) & _PAGE_INVALID) && !(pte_val(pte) & _PAGE_SWT); } static inline int pte_present(pte_t pte) { unsigned long mask = _PAGE_RO | _PAGE_INVALID | _PAGE_SWT | _PAGE_SWX; return (pte_val(pte) & mask) == _PAGE_TYPE_NONE || (!(pte_val(pte) & _PAGE_INVALID) && !(pte_val(pte) & _PAGE_SWT)); } static inline int pte_file(pte_t pte) { unsigned long mask = _PAGE_RO | _PAGE_INVALID | _PAGE_SWT; return (pte_val(pte) & mask) == _PAGE_TYPE_FILE; } static inline int pte_special(pte_t pte) { return (pte_val(pte) & _PAGE_SPECIAL); } #define __HAVE_ARCH_PTE_SAME #define pte_same(a,b) (pte_val(a) == pte_val(b)) static inline void rcp_lock(pte_t *ptep) { #ifdef CONFIG_PGSTE unsigned long *pgste = (unsigned long *) (ptep + PTRS_PER_PTE); preempt_disable(); while (test_and_set_bit(RCP_PCL_BIT, pgste)) ; #endif } static inline void rcp_unlock(pte_t *ptep) { #ifdef CONFIG_PGSTE unsigned long *pgste = (unsigned long *) (ptep + PTRS_PER_PTE); clear_bit(RCP_PCL_BIT, pgste); preempt_enable(); #endif } #include static inline void ptep_rcp_copy(pte_t *ptep) { #ifdef CONFIG_PGSTE struct page *page = virt_to_page(pte_val(*ptep)); unsigned int skey; unsigned long *pgste = (unsigned long *) (ptep + PTRS_PER_PTE); skey = page_get_storage_key(pte_val(*ptep) >> PAGE_SHIFT); if (skey & _PAGE_CHANGED) { set_bit_simple(RCP_GC_BIT, pgste); set_bit_simple(KVM_UD_BIT, pgste); } if (skey & _PAGE_REFERENCED) set_bit_simple(RCP_GR_BIT, pgste); if (test_and_clear_bit_simple(RCP_HC_BIT, pgste)) { SetPageDirty(page); set_bit_simple(KVM_UD_BIT, pgste); } if (test_and_clear_bit_simple(RCP_HR_BIT, pgste)) SetPageReferenced(page); #endif } /* * query functions pte_write/pte_dirty/pte_young only work if * pte_present() is true. Undefined behaviour if not.. */ static inline int pte_write(pte_t pte) { return (pte_val(pte) & _PAGE_RO) == 0; } static inline int pte_dirty(pte_t pte) { /* A pte is neither clean nor dirty on s/390. The dirty bit * is in the storage key. See page_test_and_clear_dirty for * details. */ return 0; } static inline int pte_young(pte_t pte) { /* A pte is neither young nor old on s/390. The young bit * is in the storage key. See page_test_and_clear_young for * details. */ return 0; } /* * pgd/pmd/pte modification functions */ #ifndef __s390x__ #define pgd_clear(pgd) do { } while (0) #define pud_clear(pud) do { } while (0) #else /* __s390x__ */ static inline void pgd_clear_kernel(pgd_t * pgd) { if ((pgd_val(*pgd) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R2) pgd_val(*pgd) = _REGION2_ENTRY_EMPTY; } static inline void pgd_clear(pgd_t * pgd) { pgd_clear_kernel(pgd); } static inline void pud_clear_kernel(pud_t *pud) { if ((pud_val(*pud) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3) pud_val(*pud) = _REGION3_ENTRY_EMPTY; } static inline void pud_clear(pud_t *pud) { pud_clear_kernel(pud); } #endif /* __s390x__ */ static inline void pmd_clear_kernel(pmd_t * pmdp) { pmd_val(*pmdp) = _SEGMENT_ENTRY_EMPTY; } static inline void pmd_clear(pmd_t *pmd) { pmd_clear_kernel(pmd); } static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep) { pte_val(*ptep) = _PAGE_TYPE_EMPTY; } /* * The following pte modification functions only work if * pte_present() is true. Undefined behaviour if not.. */ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) { pte_val(pte) &= _PAGE_CHG_MASK; pte_val(pte) |= pgprot_val(newprot); return pte; } static inline pte_t pte_wrprotect(pte_t pte) { /* Do not clobber _PAGE_TYPE_NONE pages! */ if (!(pte_val(pte) & _PAGE_INVALID)) pte_val(pte) |= _PAGE_RO; return pte; } static inline pte_t pte_mkwrite(pte_t pte) { pte_val(pte) &= ~_PAGE_RO; return pte; } static inline pte_t pte_mkclean(pte_t pte) { /* The only user of pte_mkclean is the fork() code. We must *not* clear the *physical* page dirty bit just because fork() wants to clear the dirty bit in *one* of the page's mappings. So we just do nothing. */ return pte; } static inline pte_t pte_mkdirty(pte_t pte) { /* We do not explicitly set the dirty bit because the * sske instruction is slow. It is faster to let the * next instruction set the dirty bit. */ return pte; } static inline pte_t pte_mkold(pte_t pte) { /* S/390 doesn't keep its dirty/referenced bit in the pte. * There is no point in clearing the real referenced bit. */ return pte; } static inline pte_t pte_mkyoung(pte_t pte) { /* S/390 doesn't keep its dirty/referenced bit in the pte. * There is no point in setting the real referenced bit. */ return pte; } static inline pte_t pte_mkspecial(pte_t pte) { pte_val(pte) |= _PAGE_SPECIAL; return pte; } #ifdef CONFIG_HUGETLB_PAGE static inline pte_t pte_mkhuge(pte_t pte) { /* * PROT_NONE needs to be remapped from the pte type to the ste type. * The HW invalid bit is also different for pte and ste. The pte * invalid bit happens to be the same as the ste _SEGMENT_ENTRY_LARGE * bit, so we don't have to clear it. */ if (pte_val(pte) & _PAGE_INVALID) { if (pte_val(pte) & _PAGE_SWT) pte_val(pte) |= _HPAGE_TYPE_NONE; pte_val(pte) |= _SEGMENT_ENTRY_INV; } /* * Clear SW pte bits SWT and SWX, there are no SW bits in a segment * table entry. */ pte_val(pte) &= ~(_PAGE_SWT | _PAGE_SWX); /* * Also set the change-override bit because we don't need dirty bit * tracking for hugetlbfs pages. */ pte_val(pte) |= (_SEGMENT_ENTRY_LARGE | _SEGMENT_ENTRY_CO); return pte; } #endif #ifdef CONFIG_PGSTE /* * Get (and clear) the user dirty bit for a PTE. */ static inline int kvm_s390_test_and_clear_page_dirty(struct mm_struct *mm, pte_t *ptep) { int dirty; unsigned long *pgste; unsigned long pfn; struct page *page; unsigned int skey; if (!mm->context.has_pgste) return -EINVAL; rcp_lock(ptep); pgste = (unsigned long *) (ptep + PTRS_PER_PTE); pfn = pte_val(*ptep) >> PAGE_SHIFT; page = pfn_to_page(pfn); skey = page_get_storage_key(pfn); if (skey & _PAGE_CHANGED) { set_bit_simple(RCP_GC_BIT, pgste); set_bit_simple(KVM_UD_BIT, pgste); } if (test_and_clear_bit_simple(RCP_HC_BIT, pgste)) { SetPageDirty(page); set_bit_simple(KVM_UD_BIT, pgste); } dirty = test_and_clear_bit_simple(KVM_UD_BIT, pgste); if (skey & _PAGE_CHANGED) page_set_storage_key(pfn, skey & ~_PAGE_CHANGED, 1); rcp_unlock(ptep); return dirty; } #endif #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep) { #ifdef CONFIG_PGSTE unsigned long pfn; int young; unsigned long *pgste; if (!vma->vm_mm->context.has_pgste) return 0; pfn = pte_val(*ptep) >> PAGE_SHIFT; pgste = (unsigned long *) (ptep + PTRS_PER_PTE); young = ((page_get_storage_key(pfn) & _PAGE_REFERENCED) != 0); rcp_lock(ptep); if (young) set_bit_simple(RCP_GR_BIT, pgste); young |= test_and_clear_bit_simple(RCP_HR_BIT, pgste); rcp_unlock(ptep); return young; #endif return 0; } #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH static inline int ptep_clear_flush_young(struct vm_area_struct *vma, unsigned long address, pte_t *ptep) { /* No need to flush TLB * On s390 reference bits are in storage key and never in TLB * With virtualization we handle the reference bit, without we * we can simply return */ #ifdef CONFIG_PGSTE return ptep_test_and_clear_young(vma, address, ptep); #endif return 0; } static inline void __ptep_ipte(unsigned long address, pte_t *ptep) { if (!(pte_val(*ptep) & _PAGE_INVALID)) { #ifndef __s390x__ /* pto must point to the start of the segment table */ pte_t *pto = (pte_t *) (((unsigned long) ptep) & 0x7ffffc00); #else /* ipte in zarch mode can do the math */ pte_t *pto = ptep; #endif asm volatile( " ipte %2,%3" : "=m" (*ptep) : "m" (*ptep), "a" (pto), "a" (address)); } } static inline void ptep_invalidate(struct mm_struct *mm, unsigned long address, pte_t *ptep) { if (mm->context.has_pgste) { rcp_lock(ptep); __ptep_ipte(address, ptep); ptep_rcp_copy(ptep); pte_val(*ptep) = _PAGE_TYPE_EMPTY; rcp_unlock(ptep); return; } __ptep_ipte(address, ptep); pte_val(*ptep) = _PAGE_TYPE_EMPTY; } /* * This is hard to understand. ptep_get_and_clear and ptep_clear_flush * both clear the TLB for the unmapped pte. The reason is that * ptep_get_and_clear is used in common code (e.g. change_pte_range) * to modify an active pte. The sequence is * 1) ptep_get_and_clear * 2) set_pte_at * 3) flush_tlb_range * On s390 the tlb needs to get flushed with the modification of the pte * if the pte is active. The only way how this can be implemented is to * have ptep_get_and_clear do the tlb flush. In exchange flush_tlb_range * is a nop. */ #define __HAVE_ARCH_PTEP_GET_AND_CLEAR #define ptep_get_and_clear(__mm, __address, __ptep) \ ({ \ pte_t __pte = *(__ptep); \ (__mm)->context.flush_mm = 1; \ if (atomic_read(&(__mm)->context.attach_count) > 1 || \ (__mm) != current->active_mm) \ ptep_invalidate(__mm, __address, __ptep); \ else \ pte_clear((__mm), (__address), (__ptep)); \ __pte; \ }) #define __HAVE_ARCH_PTEP_CLEAR_FLUSH static inline pte_t ptep_clear_flush(struct vm_area_struct *vma, unsigned long address, pte_t *ptep) { pte_t pte = *ptep; ptep_invalidate(vma->vm_mm, address, ptep); return pte; } /* * The batched pte unmap code uses ptep_get_and_clear_full to clear the * ptes. Here an optimization is possible. tlb_gather_mmu flushes all * tlbs of an mm if it can guarantee that the ptes of the mm_struct * cannot be accessed while the batched unmap is running. In this case * full==1 and a simple pte_clear is enough. See tlb.h. */ #define __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm, unsigned long addr, pte_t *ptep, int full) { pte_t pte = *ptep; if (full) pte_clear(mm, addr, ptep); else ptep_invalidate(mm, addr, ptep); return pte; } #define __HAVE_ARCH_PTEP_SET_WRPROTECT #define ptep_set_wrprotect(__mm, __addr, __ptep) \ ({ \ pte_t __pte = *(__ptep); \ if (pte_write(__pte)) { \ (__mm)->context.flush_mm = 1; \ if (atomic_read(&(__mm)->context.attach_count) > 1 || \ (__mm) != current->active_mm) \ ptep_invalidate(__mm, __addr, __ptep); \ set_pte_at(__mm, __addr, __ptep, pte_wrprotect(__pte)); \ } \ }) #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS #define ptep_set_access_flags(__vma, __addr, __ptep, __entry, __dirty) \ ({ \ int __changed = !pte_same(*(__ptep), __entry); \ if (__changed) { \ ptep_invalidate((__vma)->vm_mm, __addr, __ptep); \ set_pte_at((__vma)->vm_mm, __addr, __ptep, __entry); \ } \ __changed; \ }) /* * Conversion functions: convert a page and protection to a page entry, * and a page entry and page directory to the page they refer to. */ static inline pte_t mk_pte_phys(unsigned long physpage, pgprot_t pgprot) { pte_t __pte; pte_val(__pte) = physpage + pgprot_val(pgprot); return __pte; } static inline pte_t mk_pte(struct page *page, pgprot_t pgprot) { unsigned long physpage = page_to_phys(page); return mk_pte_phys(physpage, pgprot); } #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1)) #define pud_index(address) (((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1)) #define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1)) #define pte_index(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE-1)) #define pgd_offset(mm, address) ((mm)->pgd + pgd_index(address)) #define pgd_offset_k(address) pgd_offset(&init_mm, address) #ifndef __s390x__ #define pmd_deref(pmd) (pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN) #define pud_deref(pmd) ({ BUG(); 0UL; }) #define pgd_deref(pmd) ({ BUG(); 0UL; }) #define pud_offset(pgd, address) ((pud_t *) pgd) #define pmd_offset(pud, address) ((pmd_t *) pud + pmd_index(address)) #else /* __s390x__ */ #define pmd_deref(pmd) (pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN) #define pud_deref(pud) (pud_val(pud) & _REGION_ENTRY_ORIGIN) #define pgd_deref(pgd) (pgd_val(pgd) & _REGION_ENTRY_ORIGIN) static inline pud_t *pud_offset(pgd_t *pgd, unsigned long address) { pud_t *pud = (pud_t *) pgd; if ((pgd_val(*pgd) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R2) pud = (pud_t *) pgd_deref(*pgd); return pud + pud_index(address); } static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address) { pmd_t *pmd = (pmd_t *) pud; if ((pud_val(*pud) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3) pmd = (pmd_t *) pud_deref(*pud); return pmd + pmd_index(address); } #endif /* __s390x__ */ #define pfn_pte(pfn,pgprot) mk_pte_phys(__pa((pfn) << PAGE_SHIFT),(pgprot)) #define pte_pfn(x) (pte_val(x) >> PAGE_SHIFT) #define pte_page(x) pfn_to_page(pte_pfn(x)) #define pmd_page(pmd) pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT) /* Find an entry in the lowest level page table.. */ #define pte_offset(pmd, addr) ((pte_t *) pmd_deref(*(pmd)) + pte_index(addr)) #define pte_offset_kernel(pmd, address) pte_offset(pmd,address) #define pte_offset_map(pmd, address) pte_offset_kernel(pmd, address) #define pte_unmap(pte) do { } while (0) /* * 31 bit swap entry format: * A page-table entry has some bits we have to treat in a special way. * Bits 0, 20 and bit 23 have to be zero, otherwise an specification * exception will occur instead of a page translation exception. The * specifiation exception has the bad habit not to store necessary * information in the lowcore. * Bit 21 and bit 22 are the page invalid bit and the page protection * bit. We set both to indicate a swapped page. * Bit 30 and 31 are used to distinguish the different page types. For * a swapped page these bits need to be zero. * This leaves the bits 1-19 and bits 24-29 to store type and offset. * We use the 5 bits from 25-29 for the type and the 20 bits from 1-19 * plus 24 for the offset. * 0| offset |0110|o|type |00| * 0 0000000001111111111 2222 2 22222 33 * 0 1234567890123456789 0123 4 56789 01 * * 64 bit swap entry format: * A page-table entry has some bits we have to treat in a special way. * Bits 52 and bit 55 have to be zero, otherwise an specification * exception will occur instead of a page translation exception. The * specifiation exception has the bad habit not to store necessary * information in the lowcore. * Bit 53 and bit 54 are the page invalid bit and the page protection * bit. We set both to indicate a swapped page. * Bit 62 and 63 are used to distinguish the different page types. For * a swapped page these bits need to be zero. * This leaves the bits 0-51 and bits 56-61 to store type and offset. * We use the 5 bits from 57-61 for the type and the 53 bits from 0-51 * plus 56 for the offset. * | offset |0110|o|type |00| * 0000000000111111111122222222223333333333444444444455 5555 5 55566 66 * 0123456789012345678901234567890123456789012345678901 2345 6 78901 23 */ #ifndef __s390x__ #define __SWP_OFFSET_MASK (~0UL >> 12) #else #define __SWP_OFFSET_MASK (~0UL >> 11) #endif static inline pte_t mk_swap_pte(unsigned long type, unsigned long offset) { pte_t pte; offset &= __SWP_OFFSET_MASK; pte_val(pte) = _PAGE_TYPE_SWAP | ((type & 0x1f) << 2) | ((offset & 1UL) << 7) | ((offset & ~1UL) << 11); return pte; } #define __swp_type(entry) (((entry).val >> 2) & 0x1f) #define __swp_offset(entry) (((entry).val >> 11) | (((entry).val >> 7) & 1)) #define __swp_entry(type,offset) ((swp_entry_t) { pte_val(mk_swap_pte((type),(offset))) }) #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) #ifndef __s390x__ # define PTE_FILE_MAX_BITS 26 #else /* __s390x__ */ # define PTE_FILE_MAX_BITS 59 #endif /* __s390x__ */ #define pte_to_pgoff(__pte) \ ((((__pte).pte >> 12) << 7) + (((__pte).pte >> 1) & 0x7f)) #define pgoff_to_pte(__off) \ ((pte_t) { ((((__off) & 0x7f) << 1) + (((__off) >> 7) << 12)) \ | _PAGE_TYPE_FILE }) #endif /* !__ASSEMBLY__ */ #define kern_addr_valid(addr) (1) extern int vmem_add_mapping(unsigned long start, unsigned long size); extern int vmem_remove_mapping(unsigned long start, unsigned long size); extern int s390_enable_sie(void); /* * No page table caches to initialise */ #define pgtable_cache_init() do { } while (0) #include #endif /* _S390_PAGE_H */