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s390: disable pfmf for clear page instruction

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Wit the introduction of large pages Linux also used pfmf for page
clearing. The current implementation is not ideal, though:
- currently we set usage intent=0, but cleared pages are often used
directly after the clearing
- z/VM does not yet provide EDAT
- KVM does have to intercept PFMF even for resident pages

Lets just the mvcl loop in all cases until we have a well defined
pattern were pfmf is besser.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Christian Borntraeger 2013-05-06 21:44:36 +02:00 committed by Martin Schwidefsky
parent 7678dcfb31
commit 617e164c35
1 changed files with 8 additions and 12 deletions
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20
arch/s390/include/asm/page.h
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@ -32,7 +32,7 @@
void storage_key_init_range(unsigned long start, unsigned long end);
static unsigned long pfmf(unsigned long function, unsigned long address)
static inline unsigned long pfmf(unsigned long function, unsigned long address)
{
asm volatile(
" .insn rre,0xb9af0000,%[function],%[address]"
@ -44,17 +44,13 @@ static unsigned long pfmf(unsigned long function, unsigned long address)
static inline void clear_page(void *page)
{
if (MACHINE_HAS_PFMF) {
pfmf(0x10000, (unsigned long)page);
} else {
register unsigned long reg1 asm ("1") = 0;
register void *reg2 asm ("2") = page;
register unsigned long reg3 asm ("3") = 4096;
asm volatile(
" mvcl 2,0"
: "+d" (reg2), "+d" (reg3) : "d" (reg1)
: "memory", "cc");
}
register unsigned long reg1 asm ("1") = 0;
register void *reg2 asm ("2") = page;
register unsigned long reg3 asm ("3") = 4096;
asm volatile(
" mvcl 2,0"
: "+d" (reg2), "+d" (reg3) : "d" (reg1)
: "memory", "cc");
}
static inline void copy_page(void *to, void *from)