diff options
Diffstat (limited to 'arch/s390/include/asm/pgtable.h')
| -rw-r--r-- | arch/s390/include/asm/pgtable.h | 1093 |
1 files changed, 1093 insertions, 0 deletions
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h new file mode 100644 index 000000000000..0bdb704ae051 --- /dev/null +++ b/arch/s390/include/asm/pgtable.h @@ -0,0 +1,1093 @@ +/* + * 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 <linux/sched.h> +#include <linux/mm_types.h> +#include <asm/bitops.h> +#include <asm/bug.h> +#include <asm/processor.h> + +extern pgd_t swapper_pg_dir[] __attribute__ ((aligned (4096))); +extern void paging_init(void); +extern void vmem_map_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, pte) do { } while (0) + +/* + * ZERO_PAGE is a global shared page that is always zero: used + * for zero-mapped memory areas etc.. + */ +extern char empty_zero_page[PAGE_SIZE]; +#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) +#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) / 1GB (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. + */ +#ifndef __s390x__ +#define VMALLOC_START 0x78000000UL +#define VMALLOC_END 0x7e000000UL +#define VMEM_MAP_END 0x80000000UL +#else /* __s390x__ */ +#define VMALLOC_START 0x3e000000000UL +#define VMALLOC_END 0x3e040000000UL +#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 |0IP0| OS | + * 0000000000111111111122222222223333333333444444444455555555556666 + * 0123456789012345678901234567890123456789012345678901234567890123 + * + * I Page-Invalid Bit: Page is not available for address-translation + * P Page-Protection Bit: Store access not possible for page + * + * 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_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 +#define _PAGE_TYPE_EX_RO 0x202 +#define _PAGE_TYPE_EX_RW 0x002 + +/* + * 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 + * _PAGE_TYPE_EX_RO 0110 -> 1110 + * _PAGE_TYPE_EX_RW 0010 -> 1010 + * + * 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 + +#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_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) + +/* Bits int the storage key */ +#define _PAGE_CHANGED 0x02 /* HW changed bit */ +#define _PAGE_REFERENCED 0x04 /* HW referenced bit */ + +/* + * 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_EX_RO __pgprot(_PAGE_TYPE_EX_RO) +#define PAGE_EX_RW __pgprot(_PAGE_TYPE_EX_RW) + +#define PAGE_KERNEL PAGE_RW +#define PAGE_COPY PAGE_RO + +/* + * Dependent on the EXEC_PROTECT option s390 can do execute protection. + * Write permission always implies read permission. In theory with a + * primary/secondary page table execute only can be implemented but + * it would cost an additional bit in the pte to distinguish all the + * different pte types. To avoid that execute permission currently + * implies read permission as well. + */ + /*xwr*/ +#define __P000 PAGE_NONE +#define __P001 PAGE_RO +#define __P010 PAGE_RO +#define __P011 PAGE_RO +#define __P100 PAGE_EX_RO +#define __P101 PAGE_EX_RO +#define __P110 PAGE_EX_RO +#define __P111 PAGE_EX_RO + +#define __S000 PAGE_NONE +#define __S001 PAGE_RO +#define __S010 PAGE_RW +#define __S011 PAGE_RW +#define __S100 PAGE_EX_RO +#define __S101 PAGE_EX_RO +#define __S110 PAGE_EX_RW +#define __S111 PAGE_EX_RW + +#ifndef __s390x__ +# define PxD_SHADOW_SHIFT 1 +#else /* __s390x__ */ +# define PxD_SHADOW_SHIFT 2 +#endif /* __s390x__ */ + +static inline void *get_shadow_table(void *table) +{ + unsigned long addr, offset; + struct page *page; + + addr = (unsigned long) table; + offset = addr & ((PAGE_SIZE << PxD_SHADOW_SHIFT) - 1); + page = virt_to_page((void *)(addr ^ offset)); + return (void *)(addr_t)(page->index ? (page->index | offset) : 0UL); +} + +/* + * 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; + if (mm->context.noexec) { + if (!(pte_val(entry) & _PAGE_INVALID) && + (pte_val(entry) & _PAGE_SWX)) + pte_val(entry) |= _PAGE_RO; + else + pte_val(entry) = _PAGE_TYPE_EMPTY; + ptep[PTRS_PER_PTE] = 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 +} + +/* forward declaration for SetPageUptodate in page-flags.h*/ +static inline void page_clear_dirty(struct page *page); +#include <linux/page-flags.h> + +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(page_to_phys(page)); + if (skey & _PAGE_CHANGED) + set_bit_simple(RCP_GC_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); + 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_t *shadow = get_shadow_table(pgd); + + pgd_clear_kernel(pgd); + if (shadow) + pgd_clear_kernel(shadow); +} + +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_t *shadow = get_shadow_table(pud); + + pud_clear_kernel(pud); + if (shadow) + pud_clear_kernel(shadow); +} + +#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_t *shadow = get_shadow_table(pmd); + + pmd_clear_kernel(pmd); + if (shadow) + pmd_clear_kernel(shadow); +} + +static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep) +{ + if (mm->context.pgstes) + ptep_rcp_copy(ptep); + pte_val(*ptep) = _PAGE_TYPE_EMPTY; + if (mm->context.noexec) + pte_val(ptep[PTRS_PER_PTE]) = _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; +} + +#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 physpage; + int young; + unsigned long *pgste; + + if (!vma->vm_mm->context.pgstes) + return 0; + physpage = pte_val(*ptep) & PAGE_MASK; + pgste = (unsigned long *) (ptep + PTRS_PER_PTE); + + young = ((page_get_storage_key(physpage) & _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.pgstes) { + 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; + if (mm->context.noexec) { + __ptep_ipte(address, ptep + PTRS_PER_PTE); + pte_val(*(ptep + PTRS_PER_PTE)) = _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); \ + if (atomic_read(&(__mm)->mm_users) > 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)) { \ + if (atomic_read(&(__mm)->mm_users) > 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; \ +}) + +/* + * Test and clear dirty bit in storage key. + * We can't clear the changed bit atomically. This is a potential + * race against modification of the referenced bit. This function + * should therefore only be called if it is not mapped in any + * address space. + */ +#define __HAVE_ARCH_PAGE_TEST_DIRTY +static inline int page_test_dirty(struct page *page) +{ + return (page_get_storage_key(page_to_phys(page)) & _PAGE_CHANGED) != 0; +} + +#define __HAVE_ARCH_PAGE_CLEAR_DIRTY +static inline void page_clear_dirty(struct page *page) +{ + page_set_storage_key(page_to_phys(page), PAGE_DEFAULT_KEY); +} + +/* + * Test and clear referenced bit in storage key. + */ +#define __HAVE_ARCH_PAGE_TEST_AND_CLEAR_YOUNG +static inline int page_test_and_clear_young(struct page *page) +{ + unsigned long physpage = page_to_phys(page); + int ccode; + + asm volatile( + " rrbe 0,%1\n" + " ipm %0\n" + " srl %0,28\n" + : "=d" (ccode) : "a" (physpage) : "cc" ); + return ccode & 2; +} + +/* + * 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_offset_map_nested(pmd, address) pte_offset_kernel(pmd, address) +#define pte_unmap(pte) do { } while (0) +#define pte_unmap_nested(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 <asm-generic/pgtable.h> + +#endif /* _S390_PAGE_H */ |