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Commit f7f8d7e5 authored by Heiko Carstens's avatar Heiko Carstens Committed by Martin Schwidefsky
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s390/mm: speedup storage key initialization 



Use sske with multiple block control to initialize storage keys within
a 1 MB frame at once.
It turned out that the sske with mb=1 is an order of magnitude faster
than pfmf. This is only an issue for very large systems (several 100GB)
where storage key initialization could last more than a minute.

Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 1bca09f7

arch/s390/mm/pageattr.c

+9 −15
Original line number Diff line number Diff line
@@ -9,31 +9,25 @@ 
#include <asm/pgtable.h>

#include <asm/page.h>



static inline unsigned long sske_frame(unsigned long addr, unsigned char skey)

{

	asm volatile(".insn rrf,0xb22b0000,%[skey],%[addr],9,0"

		     : [addr] "+a" (addr) : [skey] "d" (skey));

	return addr;

}



void storage_key_init_range(unsigned long start, unsigned long end)

{

	unsigned long boundary, function, size;

	unsigned long boundary, size;



	while (start < end) {

		if (MACHINE_HAS_EDAT2) {

			/* set storage keys for a 2GB frame */

			function = 0x22000 | PAGE_DEFAULT_KEY;

			size = 1UL << 31;

			boundary = (start + size) & ~(size - 1);

			if (boundary <= end) {

				do {

					start = pfmf(function, start);

				} while (start < boundary);

				continue;

			}

		}

		if (MACHINE_HAS_EDAT1) {

			/* set storage keys for a 1MB frame */

			function = 0x21000 | PAGE_DEFAULT_KEY;

			size = 1UL << 20;

			boundary = (start + size) & ~(size - 1);

			if (boundary <= end) {

				do {

					start = pfmf(function, start);

					start = sske_frame(start, PAGE_DEFAULT_KEY);

				} while (start < boundary);

				continue;

			}