linux/arch/s390/mm/hugetlbpage.c
Martin Schwidefsky 5614dd920a s390/mm: implement soft-dirty bits for user memory change tracking
Use bit 2**1 of the pte and bit 2**14 of the pmd for the soft dirty
bit. The fault mechanism to do dirty tracking is already in place.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-10-14 14:32:05 +02:00

153 lines
4.5 KiB
C

/*
* IBM System z Huge TLB Page Support for Kernel.
*
* Copyright IBM Corp. 2007
* Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
*/
#include <linux/mm.h>
#include <linux/hugetlb.h>
static inline pmd_t __pte_to_pmd(pte_t pte)
{
pmd_t pmd;
/*
* Convert encoding pte bits pmd bits
* lIR.uswrdy.p dy..R...I...wr
* empty 010.000000.0 -> 00..0...1...00
* prot-none, clean, old 111.000000.1 -> 00..1...1...00
* prot-none, clean, young 111.000001.1 -> 01..1...1...00
* prot-none, dirty, old 111.000010.1 -> 10..1...1...00
* prot-none, dirty, young 111.000011.1 -> 11..1...1...00
* read-only, clean, old 111.000100.1 -> 00..1...1...01
* read-only, clean, young 101.000101.1 -> 01..1...0...01
* read-only, dirty, old 111.000110.1 -> 10..1...1...01
* read-only, dirty, young 101.000111.1 -> 11..1...0...01
* read-write, clean, old 111.001100.1 -> 00..1...1...11
* read-write, clean, young 101.001101.1 -> 01..1...0...11
* read-write, dirty, old 110.001110.1 -> 10..0...1...11
* read-write, dirty, young 100.001111.1 -> 11..0...0...11
* HW-bits: R read-only, I invalid
* SW-bits: p present, y young, d dirty, r read, w write, s special,
* u unused, l large
*/
if (pte_present(pte)) {
pmd_val(pmd) = pte_val(pte) & PAGE_MASK;
pmd_val(pmd) |= (pte_val(pte) & _PAGE_READ) >> 4;
pmd_val(pmd) |= (pte_val(pte) & _PAGE_WRITE) >> 4;
pmd_val(pmd) |= (pte_val(pte) & _PAGE_INVALID) >> 5;
pmd_val(pmd) |= (pte_val(pte) & _PAGE_PROTECT);
pmd_val(pmd) |= (pte_val(pte) & _PAGE_DIRTY) << 10;
pmd_val(pmd) |= (pte_val(pte) & _PAGE_YOUNG) << 10;
pmd_val(pmd) |= (pte_val(pte) & _PAGE_SOFT_DIRTY) << 13;
} else
pmd_val(pmd) = _SEGMENT_ENTRY_INVALID;
return pmd;
}
static inline pte_t __pmd_to_pte(pmd_t pmd)
{
pte_t pte;
/*
* Convert encoding pmd bits pte bits
* dy..R...I...wr lIR.uswrdy.p
* empty 00..0...1...00 -> 010.000000.0
* prot-none, clean, old 00..1...1...00 -> 111.000000.1
* prot-none, clean, young 01..1...1...00 -> 111.000001.1
* prot-none, dirty, old 10..1...1...00 -> 111.000010.1
* prot-none, dirty, young 11..1...1...00 -> 111.000011.1
* read-only, clean, old 00..1...1...01 -> 111.000100.1
* read-only, clean, young 01..1...0...01 -> 101.000101.1
* read-only, dirty, old 10..1...1...01 -> 111.000110.1
* read-only, dirty, young 11..1...0...01 -> 101.000111.1
* read-write, clean, old 00..1...1...11 -> 111.001100.1
* read-write, clean, young 01..1...0...11 -> 101.001101.1
* read-write, dirty, old 10..0...1...11 -> 110.001110.1
* read-write, dirty, young 11..0...0...11 -> 100.001111.1
* HW-bits: R read-only, I invalid
* SW-bits: p present, y young, d dirty, r read, w write, s special,
* u unused, l large
*/
if (pmd_present(pmd)) {
pte_val(pte) = pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN_LARGE;
pte_val(pte) |= _PAGE_LARGE | _PAGE_PRESENT;
pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_READ) << 4;
pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_WRITE) << 4;
pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_INVALID) << 5;
pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_PROTECT);
pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_DIRTY) >> 10;
pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_YOUNG) >> 10;
pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_SOFT_DIRTY) >> 13;
} else
pte_val(pte) = _PAGE_INVALID;
return pte;
}
void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t pte)
{
pmd_t pmd = __pte_to_pmd(pte);
pmd_val(pmd) |= _SEGMENT_ENTRY_LARGE;
*(pmd_t *) ptep = pmd;
}
pte_t huge_ptep_get(pte_t *ptep)
{
pmd_t pmd = *(pmd_t *) ptep;
return __pmd_to_pte(pmd);
}
pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
unsigned long addr, pte_t *ptep)
{
pmd_t *pmdp = (pmd_t *) ptep;
pte_t pte = huge_ptep_get(ptep);
pmdp_flush_direct(mm, addr, pmdp);
pmd_val(*pmdp) = _SEGMENT_ENTRY_EMPTY;
return pte;
}
pte_t *huge_pte_alloc(struct mm_struct *mm,
unsigned long addr, unsigned long sz)
{
pgd_t *pgdp;
pud_t *pudp;
pmd_t *pmdp = NULL;
pgdp = pgd_offset(mm, addr);
pudp = pud_alloc(mm, pgdp, addr);
if (pudp)
pmdp = pmd_alloc(mm, pudp, addr);
return (pte_t *) pmdp;
}
pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
{
pgd_t *pgdp;
pud_t *pudp;
pmd_t *pmdp = NULL;
pgdp = pgd_offset(mm, addr);
if (pgd_present(*pgdp)) {
pudp = pud_offset(pgdp, addr);
if (pud_present(*pudp))
pmdp = pmd_offset(pudp, addr);
}
return (pte_t *) pmdp;
}
int pmd_huge(pmd_t pmd)
{
return pmd_large(pmd);
}
int pud_huge(pud_t pud)
{
return 0;
}