On 2021/8/14 5:12, Raghavendra Rao Ananta wrote:
Add a minimalistic library support to access the virtual timers,
that can be used for simple timing functionalities, such as
introducing delays in the guest.
Signed-off-by: Raghavendra Rao Ananta <rananta@xxxxxxxxxx>
---
.../kvm/include/aarch64/arch_timer.h | 138 ++++++++++++++++++
1 file changed, 138 insertions(+)
create mode 100644 tools/testing/selftests/kvm/include/aarch64/arch_timer.h
diff --git a/tools/testing/selftests/kvm/include/aarch64/arch_timer.h b/tools/testing/selftests/kvm/include/aarch64/arch_timer.h
new file mode 100644
index 000000000000..e6144ab95348
--- /dev/null
+++ b/tools/testing/selftests/kvm/include/aarch64/arch_timer.h
@@ -0,0 +1,138 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * ARM Generic Interrupt Controller (GIC) specific defines
This isn't GIC specific, but arch timer.
+ */
+
+#ifndef SELFTEST_KVM_ARCH_TIMER_H
+#define SELFTEST_KVM_ARCH_TIMER_H
+
+#include <linux/sizes.h>
Do we really need it?
+
+#include "processor.h"
+
+enum arch_timer {
+ VIRTUAL,
+ PHYSICAL,
+};
+
+#define CTL_ENABLE (1 << 0)
+#define CTL_ISTATUS (1 << 2)
+#define CTL_IMASK (1 << 1)
nitpick: Move CTL_IMASK before CTL_ISTATUS ?
+
+#define msec_to_cycles(msec) \
+ (timer_get_cntfrq() * (uint64_t)(msec) / 1000)
+
+#define usec_to_cycles(usec) \
+ (timer_get_cntfrq() * (uint64_t)(usec) / 1000000)
+
+#define cycles_to_usec(cycles) \
+ ((uint64_t)(cycles) * 1000000 / timer_get_cntfrq())
+
+static inline uint32_t timer_get_cntfrq(void)
+{
+ return read_sysreg(cntfrq_el0);
+}
+
+static inline uint64_t timer_get_cntct(enum arch_timer timer)
+{
+ isb();
+
+ switch (timer) {
+ case VIRTUAL:
+ return read_sysreg(cntvct_el0);
+ case PHYSICAL:
+ return read_sysreg(cntpct_el0);
+ default:
+ GUEST_ASSERT_1(0, timer);
+ }
+
+ /* We should not reach here */
+ return 0;
+}
+
+static inline void timer_set_cval(enum arch_timer timer, uint64_t cval)
+{
+ switch (timer) {
+ case VIRTUAL:
+ return write_sysreg(cntv_cval_el0, cval);
+ case PHYSICAL:
+ return write_sysreg(cntp_cval_el0, cval);
+ default:
+ GUEST_ASSERT_1(0, timer);
+ }
+
+ isb();
ISB should be performed before 'return'. And the same for
timer_set_{tval,ctl}.
Thanks,
Zenghui
