Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-12-22 02:52:56 +00:00
Code Issues Packages Projects Releases Wiki Activity
f2db2e6cb3
linux/arch/s390/include/asm/pgtable.h
Martin Schwidefsky 043d07084b [S390] Remove data execution protection 
The noexec support on s390 does not rely on a bit in the page table
entry but utilizes the secondary space mode to distinguish between
memory accesses for instructions vs. data. The noexec code relies
on the assumption that the cpu will always use the secondary space
page table for data accesses while it is running in the secondary
space mode. Up to the z9-109 class machines this has been the case.
Unfortunately this is not true anymore with z10 and later machines.
The load-relative-long instructions lrl, lgrl and lgfrl access the
memory operand using the same addressing-space mode that has been
used to fetch the instruction.
This breaks the noexec mode for all user space binaries compiled
with march=z10 or later. The only option is to remove the current
noexec support.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-05-23 10:24:28 +02:00

1131 lines
34 KiB
C
Raw Blame History

/*
* 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);
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)
/* 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_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
}
/* forward declaration for SetPageUptodate in page-flags.h*/
static inline void page_clear_dirty(struct page *page, int mapped);
#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);
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;
struct page *page;
unsigned int skey;
if (!mm->context.has_pgste)
return -EINVAL;
rcp_lock(ptep);
pgste = (unsigned long *) (ptep + PTRS_PER_PTE);
page = virt_to_page(pte_val(*ptep));
skey = page_get_storage_key(page_to_phys(page));
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_clear_dirty(page, 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 physpage;
int young;
unsigned long *pgste;
if (!vma->vm_mm->context.has_pgste)
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.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; \
})
/*
* 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, int mapped)
{
page_set_storage_key(page_to_phys(page), PAGE_DEFAULT_KEY, mapped);
}
/*
* 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_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 <asm-generic/pgtable.h>
#endif /* _S390_PAGE_H */
Reference in New Issue View Git Blame Copy Permalink