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Commit 617e164c authored by Christian Borntraeger's avatar Christian Borntraeger Committed by Martin Schwidefsky
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s390: disable pfmf for clear page instruction 



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: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 7678dcfb

arch/s390/include/asm/page.h

+8 −12
Original line number Diff line number Diff line
@@ -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]"
@@ -44,9 +44,6 @@ 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;
@@ -55,7 +52,6 @@ static inline void clear_page(void *page) 
		: "+d" (reg2), "+d" (reg3) : "d" (reg1)

		: "memory", "cc");

}

}



static inline void copy_page(void *to, void *from)

{