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: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 9 insertions, 15 deletions

diff --git a/arch/s390/mm/pageattr.c b/arch/s390/mm/pageattr.c
index d21040ed5e59..80adfbf75065 100644
--- a/arch/s390/mm/pageattr.c
+++ b/arch/s390/mm/pageattr.c
@@ -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;
                         }