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: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h
index 75ce9b0..5d64fb7 100644
--- a/arch/s390/include/asm/page.h
+++ b/arch/s390/include/asm/page.h
@@ -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 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)