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>

diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h
index 1e51f2915b2eea6a1396c7dfb2d63ffc2f671ee9..316c8503a3b4fda3824ca071065f145038b34a0c 100644 (file)
--- 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 dc8770d7173c83aec5b3475d748eee99d99e60b7..96543ac400a7820ede40f22bf9636753920456b7 100644 (file)
--- 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 990397420e6bcf8262b92806b5f5b57bff273373..8400f494623f4591a5de3e5ea6442a08fe767ed4 100644 (file)
--- 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)
 {