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linux/include/asm-s390/pgtable.h
Gerald Schaefer 9282ed9297 [S390] Cleanup in page table related code. 
Changed and simplified some page table related #defines and code.

Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2006-09-20 15:59:37 +02:00

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/*
* 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
#include <asm-generic/4level-fixup.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 <asm/bug.h>
#include <asm/processor.h>
#include <linux/threads.h>
struct vm_area_struct; /* forward declaration (include/linux/mm.h) */
struct mm_struct;
extern pgd_t swapper_pg_dir[] __attribute__ ((aligned (4096)));
extern void paging_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 22
# define PGDIR_SHIFT 22
#else /* __s390x__ */
# define PMD_SHIFT 21
# define PGDIR_SHIFT 31
#endif /* __s390x__ */
#define PMD_SIZE (1UL << PMD_SHIFT)
#define PMD_MASK (~(PMD_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
*/
#ifndef __s390x__
# define PTRS_PER_PTE 1024
# define PTRS_PER_PMD 1
# define PTRS_PER_PGD 512
#else /* __s390x__ */
# define PTRS_PER_PTE 512
# define PTRS_PER_PMD 1024
# define PTRS_PER_PGD 2048
#endif /* __s390x__ */
#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 pgd_ERROR(e) \
printk("%s:%d: bad pgd %p.\n", __FILE__, __LINE__, (void *) 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))
#ifndef __s390x__
# define VMALLOC_END (0x7fffffffL)
#else /* __s390x__ */
# define VMALLOC_END (0x40000000000L)
#endif /* __s390x__ */
/*
* 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 lenght
*
* 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 */
#define _PAGE_INVALID 0x400 /* HW invalid */
/* Mask and six different types of pages. */
#define _PAGE_TYPE_MASK 0x601
#define _PAGE_TYPE_EMPTY 0x400
#define _PAGE_TYPE_NONE 0x401
#define _PAGE_TYPE_SWAP 0x600
#define _PAGE_TYPE_FILE 0x601
#define _PAGE_TYPE_RO 0x200
#define _PAGE_TYPE_RW 0x000
#ifndef __s390x__
/* Bits in the segment table entry */
#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) */
/* Bits int the storage key */
#define _PAGE_CHANGED 0x02 /* HW changed bit */
#define _PAGE_REFERENCED 0x04 /* HW referenced bit */
#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|0x100)
#define _KERNSEG_TABLE _KERNEL_SEG_TABLE_LEN
#define USER_STD_MASK 0x00000080UL
#else /* __s390x__ */
/* Bits in the segment table entry */
#define _PMD_ENTRY_INV 0x20 /* invalid segment table entry */
#define _PMD_ENTRY 0x00
/* Bits in the region third table entry */
#define _PGD_ENTRY_INV 0x20 /* invalid region table entry */
#define _PGD_ENTRY 0x07
/*
* User and kernel page directory
*/
#define _REGION_THIRD 0x4
#define _REGION_THIRD_LEN 0x3
#define _REGION_TABLE (_REGION_THIRD|_REGION_THIRD_LEN|0x40|0x100)
#define _KERN_REGION_TABLE (_REGION_THIRD|_REGION_THIRD_LEN)
#define USER_STD_MASK 0x0000000000000080UL
/* Bits in the storage key */
#define _PAGE_CHANGED 0x02 /* HW changed bit */
#define _PAGE_REFERENCED 0x04 /* HW referenced bit */
#endif /* __s390x__ */
/*
* 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
/*
* 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..
*/
/*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(pte_t *pteptr, pte_t pteval)
{
*pteptr = pteval;
}
#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
/*
* 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 pmd_present(pmd_t pmd) { return pmd_val(pmd) & _SEG_PRESENT; }
static inline int pmd_none(pmd_t pmd) { return pmd_val(pmd) & _PAGE_TABLE_INV; }
static inline int pmd_bad(pmd_t pmd)
{
return (pmd_val(pmd) & (~PAGE_MASK & ~_PAGE_TABLE_INV)) != _PAGE_TABLE;
}
#else /* __s390x__ */
static inline int pgd_present(pgd_t pgd)
{
return (pgd_val(pgd) & ~PAGE_MASK) == _PGD_ENTRY;
}
static inline int pgd_none(pgd_t pgd)
{
return pgd_val(pgd) & _PGD_ENTRY_INV;
}
static inline int pgd_bad(pgd_t pgd)
{
return (pgd_val(pgd) & (~PAGE_MASK & ~_PGD_ENTRY_INV)) != _PGD_ENTRY;
}
static inline int pmd_present(pmd_t pmd)
{
return (pmd_val(pmd) & ~PAGE_MASK) == _PMD_ENTRY;
}
static inline int pmd_none(pmd_t pmd)
{
return pmd_val(pmd) & _PMD_ENTRY_INV;
}
static inline int pmd_bad(pmd_t pmd)
{
return (pmd_val(pmd) & (~PAGE_MASK & ~_PMD_ENTRY_INV)) != _PMD_ENTRY;
}
#endif /* __s390x__ */
static inline int pte_none(pte_t pte)
{
return (pte_val(pte) & _PAGE_TYPE_MASK) == _PAGE_TYPE_EMPTY;
}
static inline int pte_present(pte_t pte)
{
return !(pte_val(pte) & _PAGE_INVALID) ||
(pte_val(pte) & _PAGE_TYPE_MASK) == _PAGE_TYPE_NONE;
}
static inline int pte_file(pte_t pte)
{
return (pte_val(pte) & _PAGE_TYPE_MASK) == _PAGE_TYPE_FILE;
}
#define pte_same(a,b) (pte_val(a) == pte_val(b))
/*
* 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;
}
static inline int pte_read(pte_t pte)
{
/* All pages are readable since we don't use the fetch
* protection bit in the storage key.
*/
return 1;
}
/*
* pgd/pmd/pte modification functions
*/
#ifndef __s390x__
static inline void pgd_clear(pgd_t * pgdp) { }
static 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;
}
#else /* __s390x__ */
static inline void pgd_clear(pgd_t * pgdp)
{
pgd_val(*pgdp) = _PGD_ENTRY_INV | _PGD_ENTRY;
}
static inline void pmd_clear(pmd_t * pmdp)
{
pmd_val(*pmdp) = _PMD_ENTRY_INV | _PMD_ENTRY;
pmd_val1(*pmdp) = _PMD_ENTRY_INV | _PMD_ENTRY;
}
#endif /* __s390x__ */
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_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 int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
{
return 0;
}
static inline int
ptep_clear_flush_young(struct vm_area_struct *vma,
unsigned long address, pte_t *ptep)
{
/* No need to flush TLB; bits are in storage key */
return ptep_test_and_clear_young(vma, address, ptep);
}
static inline int ptep_test_and_clear_dirty(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
{
return 0;
}
static inline int
ptep_clear_flush_dirty(struct vm_area_struct *vma,
unsigned long address, pte_t *ptep)
{
/* No need to flush TLB; bits are in storage key */
return ptep_test_and_clear_dirty(vma, address, ptep);
}
static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
pte_t pte = *ptep;
pte_clear(mm, addr, ptep);
return pte;
}
static inline void __ptep_ipte(unsigned long address, pte_t *ptep)
{
if (!(pte_val(*ptep) & _PAGE_INVALID)) {
#ifndef __s390x__
/* S390 has 1mb segments, we are emulating 4MB segments */
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) );
}
pte_val(*ptep) = _PAGE_TYPE_EMPTY;
}
static inline pte_t
ptep_clear_flush(struct vm_area_struct *vma,
unsigned long address, pte_t *ptep)
{
pte_t pte = *ptep;
__ptep_ipte(address, ptep);
return pte;
}
static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
pte_t old_pte = *ptep;
set_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
}
static inline void
ptep_establish(struct vm_area_struct *vma,
unsigned long address, pte_t *ptep,
pte_t entry)
{
ptep_clear_flush(vma, address, ptep);
set_pte(ptep, entry);
}
#define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
ptep_establish(__vma, __address, __ptep, __entry)
/*
* 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 page_test_and_clear_dirty(_page) \
({ \
struct page *__page = (_page); \
unsigned long __physpage = __pa((__page-mem_map) << PAGE_SHIFT); \
int __skey = page_get_storage_key(__physpage); \
if (__skey & _PAGE_CHANGED) \
page_set_storage_key(__physpage, __skey & ~_PAGE_CHANGED);\
(__skey & _PAGE_CHANGED); \
})
/*
* Test and clear referenced bit in storage key.
*/
#define page_test_and_clear_young(page) \
({ \
struct page *__page = (page); \
unsigned long __physpage = __pa((__page-mem_map) << PAGE_SHIFT); \
int __ccode; \
asm volatile ("rrbe 0,%1\n\t" \
"ipm %0\n\t" \
"srl %0,28\n\t" \
: "=d" (__ccode) : "a" (__physpage) : "cc" ); \
(__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;
}
#define mk_pte(pg, pgprot) \
({ \
struct page *__page = (pg); \
pgprot_t __pgprot = (pgprot); \
unsigned long __physpage = __pa((__page-mem_map) << PAGE_SHIFT); \
pte_t __pte = mk_pte_phys(__physpage, __pgprot); \
__pte; \
})
#define pfn_pte(pfn, pgprot) \
({ \
pgprot_t __pgprot = (pgprot); \
unsigned long __physpage = __pa((pfn) << PAGE_SHIFT); \
pte_t __pte = mk_pte_phys(__physpage, __pgprot); \
__pte; \
})
#ifdef __s390x__
#define pfn_pmd(pfn, pgprot) \
({ \
pgprot_t __pgprot = (pgprot); \
unsigned long __physpage = __pa((pfn) << PAGE_SHIFT); \
pmd_t __pmd = __pmd(__physpage + pgprot_val(__pgprot)); \
__pmd; \
})
#endif /* __s390x__ */
#define pte_pfn(x) (pte_val(x) >> PAGE_SHIFT)
#define pte_page(x) pfn_to_page(pte_pfn(x))
#define pmd_page_kernel(pmd) (pmd_val(pmd) & PAGE_MASK)
#define pmd_page(pmd) (mem_map+(pmd_val(pmd) >> PAGE_SHIFT))
#define pgd_page_kernel(pgd) (pgd_val(pgd) & 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(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)
#ifndef __s390x__
/* Find an entry in the second-level page table.. */
static inline pmd_t * pmd_offset(pgd_t * dir, unsigned long address)
{
return (pmd_t *) dir;
}
#else /* __s390x__ */
/* Find an entry in the second-level page table.. */
#define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
#define pmd_offset(dir,addr) \
((pmd_t *) pgd_page_kernel(*(dir)) + pmd_index(addr))
#endif /* __s390x__ */
/* Find an entry in the third-level page table.. */
#define pte_index(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE-1))
#define pte_offset_kernel(pmd, address) \
((pte_t *) pmd_page_kernel(*(pmd)) + pte_index(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)
/*
* No page table caches to initialise
*/
#define pgtable_cache_init() do { } while (0)
#define __HAVE_ARCH_PTEP_ESTABLISH
#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
#define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY
#define __HAVE_ARCH_PTEP_CLEAR_DIRTY_FLUSH
#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
#define __HAVE_ARCH_PTEP_CLEAR_FLUSH
#define __HAVE_ARCH_PTEP_SET_WRPROTECT
#define __HAVE_ARCH_PTE_SAME
#define __HAVE_ARCH_PAGE_TEST_AND_CLEAR_DIRTY
#define __HAVE_ARCH_PAGE_TEST_AND_CLEAR_YOUNG
#include <asm-generic/pgtable.h>
#endif /* _S390_PAGE_H */
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