[S390] sclp: Test facility list before executing a service call.

Check if a command is available before executing. Saves some
superfluous service calls that won't succeed anyway.

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

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/s390/char/sclp_info.c b/drivers/s390/char/sclp_info.c
index 7d21dbb12fcd..a1136e052750 100644
--- a/drivers/s390/char/sclp_info.c
+++ b/drivers/s390/char/sclp_info.c
@@ -30,6 +30,8 @@ struct sclp_readinfo_sccb {
 static struct sclp_readinfo_sccb __initdata early_readinfo_sccb;
 static int __initdata early_readinfo_sccb_valid;
 
+u64 sclp_facilities;
+
 void __init sclp_readinfo_early(void)
 {
         int ret;
@@ -70,6 +72,13 @@ void __init sclp_readinfo_early(void)
         __ctl_clear_bit(0, 9);
 }
 
+void __init sclp_facilities_detect(void)
+{
+        if (!early_readinfo_sccb_valid)
+                return;
+        sclp_facilities = early_readinfo_sccb.facilities;
+}
+
 unsigned long long __init sclp_memory_detect(void)
 {
         unsigned long long memsize;