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| author | Christian Borntraeger <borntraeger@de.ibm.com> | 2009-12-07 14:52:11 +0300 |
|---|---|---|
| committer | Martin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com> | 2009-12-07 14:51:37 +0300 |
| commit | 6a985c6194017de2c062916ad1cd00dee0302c40 (patch) | |
| tree | ea19d62cd639876cc1f63e2963276d4fdf2e95b0 | |
| parent | a968cd3ef1d315b8c4c48ea65ab5aac8421c2612 (diff) | |
| download | linux-6a985c6194017de2c062916ad1cd00dee0302c40.tar.xz | |
[S390] s390: use change recording override for kernel mapping
We dont need the dirty bit if a write access is done via the kernel
mapping. In that case SetPageDirty and friends are used anyway, no
need to do that a second time. We can use the change-recording
overide function for the kernel mapping, if available.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| -rw-r--r-- | arch/s390/include/asm/pgtable.h | 4 | ||||
| -rw-r--r-- | arch/s390/mm/vmem.c | 11 |
2 files changed, 11 insertions, 4 deletions
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index 60a7b1a1702f..e2fa79cf0614 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -169,12 +169,13 @@ extern unsigned long VMALLOC_START; * 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 | + * | 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 @@ -218,6 +219,7 @@ extern unsigned long VMALLOC_START; */ /* 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 */ diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c index 5f91a38d7592..300ab012b0fd 100644 --- a/arch/s390/mm/vmem.c +++ b/arch/s390/mm/vmem.c @@ -70,8 +70,12 @@ static pte_t __ref *vmem_pte_alloc(void) pte = alloc_bootmem(PTRS_PER_PTE * sizeof(pte_t)); if (!pte) return NULL; - clear_table((unsigned long *) pte, _PAGE_TYPE_EMPTY, - PTRS_PER_PTE * sizeof(pte_t)); + if (MACHINE_HAS_HPAGE) + clear_table((unsigned long *) pte, _PAGE_TYPE_EMPTY | _PAGE_CO, + PTRS_PER_PTE * sizeof(pte_t)); + else + clear_table((unsigned long *) pte, _PAGE_TYPE_EMPTY, + PTRS_PER_PTE * sizeof(pte_t)); return pte; } @@ -112,7 +116,8 @@ static int vmem_add_mem(unsigned long start, unsigned long size, int ro) if (MACHINE_HAS_HPAGE && !(address & ~HPAGE_MASK) && (address + HPAGE_SIZE <= start + size) && (address >= HPAGE_SIZE)) { - pte_val(pte) |= _SEGMENT_ENTRY_LARGE; + pte_val(pte) |= _SEGMENT_ENTRY_LARGE | + _SEGMENT_ENTRY_CO; pmd_val(*pm_dir) = pte_val(pte); address += HPAGE_SIZE - PAGE_SIZE; continue; |