From 127c1feffff8078400f01372712c600d0f9eef51 Mon Sep 17 00:00:00 2001
From: Martin Schwidefsky <schwidefsky@de.ibm.com>
Date: Mon, 7 Oct 2013 12:12:32 +0200
Subject: [PATCH] s390/mm: do not initialize storage keys
With dirty and referenced bits implemented in software it is unnecessary
to initialize the storage key for every page. With this patch not a single
storage key operation is done for a system that does not use KVM.
For KVM set_pte_at/pgste_set_key will do the initialization for the guest
view of the storage key when the mapping for the page is established in
the host.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
arch/s390/include/asm/page.h | 7 ++++++-
arch/s390/kernel/early.c | 2 ++
arch/s390/mm/pageattr.c | 4 +++-
3 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h
index 1e51f2915b2ee..316c8503a3b4f 100644
--- a/arch/s390/include/asm/page.h
+++ b/arch/s390/include/asm/page.h
@@ -30,7 +30,12 @@
#include <asm/setup.h>
#ifndef __ASSEMBLY__
-void storage_key_init_range(unsigned long start, unsigned long end);
+static inline void storage_key_init_range(unsigned long start, unsigned long end)
+{
+#if PAGE_DEFAULT_KEY
+ __storage_key_init_range(start, end);
+#endif
+}
static inline void clear_page(void *page)
{
diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c
index dc8770d7173c8..96543ac400a78 100644
--- a/arch/s390/kernel/early.c
+++ b/arch/s390/kernel/early.c
@@ -206,6 +206,7 @@ static noinline __init void clear_bss_section(void)
*/
static noinline __init void init_kernel_storage_key(void)
{
+#if PAGE_DEFAULT_KEY
unsigned long end_pfn, init_pfn;
end_pfn = PFN_UP(__pa(&_end));
@@ -213,6 +214,7 @@ static noinline __init void init_kernel_storage_key(void)
for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
page_set_storage_key(init_pfn << PAGE_SHIFT,
PAGE_DEFAULT_KEY, 0);
+#endif
}
static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
diff --git a/arch/s390/mm/pageattr.c b/arch/s390/mm/pageattr.c
index 990397420e6bc..8400f494623f4 100644
--- a/arch/s390/mm/pageattr.c
+++ b/arch/s390/mm/pageattr.c
@@ -9,6 +9,7 @@
#include <asm/pgtable.h>
#include <asm/page.h>
+#if PAGE_DEFAULT_KEY
static inline unsigned long sske_frame(unsigned long addr, unsigned char skey)
{
asm volatile(".insn rrf,0xb22b0000,%[skey],%[addr],9,0"
@@ -16,7 +17,7 @@ static inline unsigned long sske_frame(unsigned long addr, unsigned char skey)
return addr;
}
-void storage_key_init_range(unsigned long start, unsigned long end)
+void __storage_key_init_range(unsigned long start, unsigned long end)
{
unsigned long boundary, size;
@@ -36,6 +37,7 @@ void storage_key_init_range(unsigned long start, unsigned long end)
start += PAGE_SIZE;
}
}
+#endif
static pte_t *walk_page_table(unsigned long addr)
{
--
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