[kvm-unit-tests PATCH v5 2/4] lib/s390x: add CPU timer related defines and functions

[Nico Boehr <nrb@linux.ibm.com>]

Upcoming changes will make use of the CPU timer, so add some defines and
functions to work with the CPU timer.

Since shifts for both CPU timer and TOD clock are the same, introduce a
new define S390_CLOCK_SHIFT_US. The respective shifts for CPU timer and
TOD clock reference it, so the semantic difference between the two
defines is kept.

Also add a define for the CPU timer subclass mask.

Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
---
 lib/s390x/asm/arch_def.h |  1 +
 lib/s390x/asm/time.h     | 17 ++++++++++++++++-
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/lib/s390x/asm/arch_def.h b/lib/s390x/asm/arch_def.h
index e7ae454b3a33..b92291e8ae3f 100644
--- a/lib/s390x/asm/arch_def.h
+++ b/lib/s390x/asm/arch_def.h
@@ -78,6 +78,7 @@ struct cpu {
 #define CTL0_EMERGENCY_SIGNAL			(63 - 49)
 #define CTL0_EXTERNAL_CALL			(63 - 50)
 #define CTL0_CLOCK_COMPARATOR			(63 - 52)
+#define CTL0_CPU_TIMER				(63 - 53)
 #define CTL0_SERVICE_SIGNAL			(63 - 54)
 #define CR0_EXTM_MASK			0x0000000000006200UL /* Combined external masks */
 
diff --git a/lib/s390x/asm/time.h b/lib/s390x/asm/time.h
index 7652a151e87a..d8d91d68a667 100644
--- a/lib/s390x/asm/time.h
+++ b/lib/s390x/asm/time.h
@@ -11,9 +11,13 @@
 #ifndef _ASMS390X_TIME_H_
 #define _ASMS390X_TIME_H_
 
-#define STCK_SHIFT_US	(63 - 51)
+#define S390_CLOCK_SHIFT_US	(63 - 51)
+
+#define STCK_SHIFT_US	S390_CLOCK_SHIFT_US
 #define STCK_MAX	((1UL << 52) - 1)
 
+#define CPU_TIMER_SHIFT_US	S390_CLOCK_SHIFT_US
+
 static inline uint64_t get_clock_us(void)
 {
 	uint64_t clk;
@@ -45,4 +49,15 @@ static inline void mdelay(unsigned long ms)
 	udelay(ms * 1000);
 }
 
+static inline void cpu_timer_set_ms(int64_t timeout_ms)
+{
+	int64_t timer_value = (timeout_ms * 1000) << CPU_TIMER_SHIFT_US;
+
+	asm volatile (
+		"spt %[timer_value]\n"
+		:
+		: [timer_value] "Q" (timer_value)
+	);
+}
+
 #endif
-- 
2.36.1