[kvm-unit-tests GIT PULL 06/11] lib/s390x: add CPU timer related defines and functions

Janosch Frank
2022-09-20T07:32:19Z

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 constant S390_CLOCK_SHIFT_US for this value. The respective shifts
for CPU timer and TOD clock reference it, so the semantic difference
between the two defines is kept.

Also add a constant for the CPU timer subclass mask.

Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Link: https://lore.kernel.org/r/20220823103833.156942-3-nrb@linux.ibm.com
Message-Id: <20220823103833.156942-3-nrb@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@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 e7ae454b..b92291e8 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 7652a151..d8d91d68 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
--
2.34.1