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Date:   Thu,  7 Oct 2021 23:34:30 +0000
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Subject: [PATCH v8 06/15] KVM: arm64: selftests: Add basic support for arch_timers
From:   Raghavendra Rao Ananta <rananta@google.com>
To:     Paolo Bonzini <pbonzini@redhat.com>, Marc Zyngier <maz@kernel.org>,
        Andrew Jones <drjones@redhat.com>,
        James Morse <james.morse@arm.com>,
        Alexandru Elisei <alexandru.elisei@arm.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>
Cc:     Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>, Peter Shier <pshier@google.com>,
        Ricardo Koller <ricarkol@google.com>,
        Oliver Upton <oupton@google.com>,
        Reiji Watanabe <reijiw@google.com>,
        Jing Zhang <jingzhangos@google.com>,
        Raghavendra Rao Anata <rananta@google.com>,
        linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu,
        linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

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@google.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
---
 .../kvm/include/aarch64/arch_timer.h          | 142 ++++++++++++++++++
 1 file changed, 142 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..cb7c03de3a21
--- /dev/null
+++ b/tools/testing/selftests/kvm/include/aarch64/arch_timer.h
@@ -0,0 +1,142 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * ARM Generic Timer specific interface
+ */
+
+#ifndef SELFTEST_KVM_ARCH_TIMER_H
+#define SELFTEST_KVM_ARCH_TIMER_H
+
+#include "processor.h"
+
+enum arch_timer {
+	VIRTUAL,
+	PHYSICAL,
+};
+
+#define CTL_ENABLE	(1 << 0)
+#define CTL_IMASK	(1 << 1)
+#define CTL_ISTATUS	(1 << 2)
+
+#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:
+		write_sysreg(cval, cntv_cval_el0);
+		break;
+	case PHYSICAL:
+		write_sysreg(cval, cntp_cval_el0);
+		break;
+	default:
+		GUEST_ASSERT_1(0, timer);
+	}
+
+	isb();
+}
+
+static inline uint64_t timer_get_cval(enum arch_timer timer)
+{
+	switch (timer) {
+	case VIRTUAL:
+		return read_sysreg(cntv_cval_el0);
+	case PHYSICAL:
+		return read_sysreg(cntp_cval_el0);
+	default:
+		GUEST_ASSERT_1(0, timer);
+	}
+
+	/* We should not reach here */
+	return 0;
+}
+
+static inline void timer_set_tval(enum arch_timer timer, uint32_t tval)
+{
+	switch (timer) {
+	case VIRTUAL:
+		write_sysreg(tval, cntv_tval_el0);
+		break;
+	case PHYSICAL:
+		write_sysreg(tval, cntp_tval_el0);
+		break;
+	default:
+		GUEST_ASSERT_1(0, timer);
+	}
+
+	isb();
+}
+
+static inline void timer_set_ctl(enum arch_timer timer, uint32_t ctl)
+{
+	switch (timer) {
+	case VIRTUAL:
+		write_sysreg(ctl, cntv_ctl_el0);
+		break;
+	case PHYSICAL:
+		write_sysreg(ctl, cntp_ctl_el0);
+		break;
+	default:
+		GUEST_ASSERT_1(0, timer);
+	}
+
+	isb();
+}
+
+static inline uint32_t timer_get_ctl(enum arch_timer timer)
+{
+	switch (timer) {
+	case VIRTUAL:
+		return read_sysreg(cntv_ctl_el0);
+	case PHYSICAL:
+		return read_sysreg(cntp_ctl_el0);
+	default:
+		GUEST_ASSERT_1(0, timer);
+	}
+
+	/* We should not reach here */
+	return 0;
+}
+
+static inline void timer_set_next_cval_ms(enum arch_timer timer, uint32_t msec)
+{
+	uint64_t now_ct = timer_get_cntct(timer);
+	uint64_t next_ct = now_ct + msec_to_cycles(msec);
+
+	timer_set_cval(timer, next_ct);
+}
+
+static inline void timer_set_next_tval_ms(enum arch_timer timer, uint32_t msec)
+{
+	timer_set_tval(timer, msec_to_cycles(msec));
+}
+
+#endif /* SELFTEST_KVM_ARCH_TIMER_H */
-- 
2.33.0.882.g93a45727a2-goog