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authorJan Glauber <jang@linux.vnet.ibm.com>2011-10-30 15:17:04 +0100
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2011-10-30 15:16:45 +0100
commit80376f347d70ce5fcfb98105d83624518e0911d6 (patch)
tree9592c2968b21812d1ad1a200af70e959fb74d463 /arch/s390
parent388186bc920d9200202e4d25de66fa95b1b8fc68 (diff)
[S390] Introduce get_clock_fast()
Add get_clock_fast() which uses the slightly faster stckf if available. If stckf is not available fall back to stck, which has the same width. Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/include/asm/timex.h11
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/s390/include/asm/timex.h b/arch/s390/include/asm/timex.h
index 88829a40af6..d610bef9c5e 100644
--- a/arch/s390/include/asm/timex.h
+++ b/arch/s390/include/asm/timex.h
@@ -86,6 +86,17 @@ static inline void get_clock_ext(char *clk)
asm volatile("stcke %0" : "=Q" (*clk) : : "cc");
}
+static inline unsigned long long get_clock_fast(void)
+{
+ unsigned long long clk;
+
+ if (test_facility(25))
+ asm volatile(".insn s,0xb27c0000,%0" : "=Q" (clk) : : "cc");
+ else
+ clk = get_clock();
+ return clk;
+}
+
static inline unsigned long long get_clock_xt(void)
{
unsigned char clk[16];