From: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>
Add apic timer mode transition test.
Signed-off-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>
---
lib/x86/apic-defs.h | 1 +
x86/apic.c | 78 +++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 79 insertions(+)
diff --git a/lib/x86/apic-defs.h b/lib/x86/apic-defs.h
index e0c3cca..a7bc6a0 100644
--- a/lib/x86/apic-defs.h
+++ b/lib/x86/apic-defs.h
@@ -91,6 +91,7 @@
#define APIC_TIMER_BASE_CLKIN 0x0
#define APIC_TIMER_BASE_TMBASE 0x1
#define APIC_TIMER_BASE_DIV 0x2
+#define APIC_LVT_TIMER_MASK (3 << 17)
#define APIC_LVT_TIMER_ONESHOT (0 << 17)
#define APIC_LVT_TIMER_PERIODIC (1 << 17)
#define APIC_LVT_TIMER_TSCDEADLINE (2 << 17)
diff --git a/x86/apic.c b/x86/apic.c
index eb78579..6cfb52d 100644
--- a/x86/apic.c
+++ b/x86/apic.c
@@ -458,6 +458,83 @@ static void test_physical_broadcast(void)
report("APIC physical broadcast shorthand", broadcast_received(ncpus));
}
+void wait_until_tmcct_is_zero(uint32_t initial_count, bool stop_when_half)
+{
+ uint32_t tmcct = apic_read(APIC_TMCCT);
+
+ if (tmcct) {
+ while (tmcct > (initial_count / 2))
+ tmcct = apic_read(APIC_TMCCT);
+
+ if ( stop_when_half )
+ return;
+
+ /* Wait until the counter reach 0 or wrap-around */
+ while ( tmcct <= (initial_count / 2) && tmcct > 0 )
+ tmcct = apic_read(APIC_TMCCT);
+ }
+}
+
+static inline void apic_change_mode(unsigned long new_mode)
+{
+ uint32_t lvtt;
+
+ lvtt = apic_read(APIC_LVTT);
+ apic_write(APIC_LVTT, (lvtt & ~APIC_LVT_TIMER_MASK) | new_mode);
+}
+
+static void test_apic_change_mode()
+{
+ uint32_t tmict = 0x999999;
+
+ printf("starting apic change mode\n");
+
+ apic_write(APIC_TMICT, tmict);
+
+ apic_change_mode(APIC_LVT_TIMER_PERIODIC);
+
+ report("TMICT value reset", apic_read(APIC_TMICT) == tmict);
+
+ /* Testing one-shot */
+ apic_change_mode(APIC_LVT_TIMER_ONESHOT);
+ apic_write(APIC_TMICT, tmict);
+ report("TMCCT should have a non-zero value", apic_read(APIC_TMCCT));
+
+ wait_until_tmcct_is_zero(tmict, false);
+ report("TMCCT should have reached 0", !apic_read(APIC_TMCCT));
+
+ /*
+ * Write TMICT before changing mode from one-shot to periodic TMCCT should
+ * be reset to TMICT periodicly
+ */
+ apic_write(APIC_TMICT, tmict);
+ wait_until_tmcct_is_zero(tmict, true);
+ apic_change_mode(APIC_LVT_TIMER_PERIODIC);
+ report("TMCCT should have a non-zero value", apic_read(APIC_TMCCT));
+
+ /*
+ * After the change of mode, the counter should not be reset and continue
+ * counting down from where it was
+ */
+ report("TMCCT should not be reset to TMICT value", apic_read(APIC_TMCCT) < (tmict / 2));
+ wait_until_tmcct_is_zero(tmict, false);
+ report("TMCCT should be reset to the initial-count", apic_read(APIC_TMCCT) > (tmict / 2));
+
+ wait_until_tmcct_is_zero(tmict, true);
+ /*
+ * Keep the same TMICT and change timer mode to one-shot
+ * TMCCT should be > 0 and count-down to 0
+ */
+ apic_change_mode(APIC_LVT_TIMER_ONESHOT);
+ report("TMCCT should not be reset to init", apic_read(APIC_TMCCT) < (tmict / 2));
+ wait_until_tmcct_is_zero(tmict, false);
+ report("TMCCT should have reach zero", !apic_read(APIC_TMCCT));
+
+ /* now tmcct == 0 and tmict != 0 */
+ apic_change_mode(APIC_LVT_TIMER_PERIODIC);
+ report("TMCCT should stay at zero", !apic_read(APIC_TMCCT));
+}
+
int main()
{
setup_vm();
@@ -478,6 +555,7 @@ int main()
test_multiple_nmi();
test_apic_timer_one_shot();
+ test_apic_change_mode();
test_tsc_deadline_timer();
return report_summary();
--
2.7.4
