[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>
diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c
index 9fcf3f1..e6289ee 100644
--- a/arch/s390/kernel/early.c
+++ b/arch/s390/kernel/early.c
@@ -275,6 +275,7 @@
sort_main_extable();
setup_lowcore_early();
sclp_readinfo_early();
+ sclp_facilities_detect();
memsize = sclp_memory_detect();
#ifndef CONFIG_64BIT
/*
diff --git a/drivers/s390/char/sclp.h b/drivers/s390/char/sclp.h
index cb5888f..c7318a1 100644
--- a/drivers/s390/char/sclp.h
+++ b/drivers/s390/char/sclp.h
@@ -79,6 +79,11 @@
u16 response_code;
} __attribute__((packed));
+extern u64 sclp_facilities;
+
+#define SCLP_HAS_CHP_INFO (sclp_facilities & 0x8000000000000000ULL)
+#define SCLP_HAS_CHP_RECONFIG (sclp_facilities & 0x2000000000000000ULL)
+
struct gds_subvector {
u8 length;
u8 key;
diff --git a/drivers/s390/char/sclp_chp.c b/drivers/s390/char/sclp_chp.c
index a66b914..c68f5e7 100644
--- a/drivers/s390/char/sclp_chp.c
+++ b/drivers/s390/char/sclp_chp.c
@@ -55,6 +55,8 @@
struct chp_cfg_data *data;
int rc;
+ if (!SCLP_HAS_CHP_RECONFIG)
+ return -EOPNOTSUPP;
/* Prepare sccb. */
data = (struct chp_cfg_data *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
if (!data)
@@ -152,6 +154,8 @@
struct chp_info_data *data;
int rc;
+ if (!SCLP_HAS_CHP_INFO)
+ return -EOPNOTSUPP;
/* Prepare sccb. */
data = (struct chp_info_data *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
if (!data)
diff --git a/drivers/s390/char/sclp_info.c b/drivers/s390/char/sclp_info.c
index 7d21dbb..a1136e0 100644
--- a/drivers/s390/char/sclp_info.c
+++ b/drivers/s390/char/sclp_info.c
@@ -30,6 +30,8 @@
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 @@
__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;
diff --git a/include/asm-s390/sclp.h b/include/asm-s390/sclp.h
index ddfaa8d..cb9faf1 100644
--- a/include/asm-s390/sclp.h
+++ b/include/asm-s390/sclp.h
@@ -28,6 +28,7 @@
};
void sclp_readinfo_early(void);
+void sclp_facilities_detect(void);
unsigned long long sclp_memory_detect(void);
int sclp_sdias_blk_count(void);
int sclp_sdias_copy(void *dest, int blk_num, int nr_blks);