KVM: riscv: selftests: Add sstc timer test

Add a KVM selftests to validate the Sstc timer functionality.
The test was ported from arm64 arch timer test.

Signed-off-by: Haibo Xu <haibo1.xu@intel.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>

2 files changed, 81 insertions, 0 deletions

diff --git a/tools/testing/selftests/kvm/include/riscv/arch_timer.h b/tools/testing/selftests/kvm/include/riscv/arch_timer.h
new file mode 100644
index 000000000000..225d81dad064
--- /dev/null
+++ b/tools/testing/selftests/kvm/include/riscv/arch_timer.h
@@ -0,0 +1,71 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * RISC-V Arch Timer(sstc) specific interface
+ *
+ * Copyright (c) 2024 Intel Corporation
+ */
+
+#ifndef SELFTEST_KVM_ARCH_TIMER_H
+#define SELFTEST_KVM_ARCH_TIMER_H
+
+#include <asm/csr.h>
+#include <asm/vdso/processor.h>
+
+static unsigned long timer_freq;
+
+#define msec_to_cycles(msec)	\
+	((timer_freq) * (uint64_t)(msec) / 1000)
+
+#define usec_to_cycles(usec)	\
+	((timer_freq) * (uint64_t)(usec) / 1000000)
+
+#define cycles_to_usec(cycles) \
+	((uint64_t)(cycles) * 1000000 / (timer_freq))
+
+static inline uint64_t timer_get_cycles(void)
+{
+	return csr_read(CSR_TIME);
+}
+
+static inline void timer_set_cmp(uint64_t cval)
+{
+	csr_write(CSR_STIMECMP, cval);
+}
+
+static inline uint64_t timer_get_cmp(void)
+{
+	return csr_read(CSR_STIMECMP);
+}
+
+static inline void timer_irq_enable(void)
+{
+	csr_set(CSR_SIE, IE_TIE);
+}
+
+static inline void timer_irq_disable(void)
+{
+	csr_clear(CSR_SIE, IE_TIE);
+}
+
+static inline void timer_set_next_cmp_ms(uint32_t msec)
+{
+	uint64_t now_ct = timer_get_cycles();
+	uint64_t next_ct = now_ct + msec_to_cycles(msec);
+
+	timer_set_cmp(next_ct);
+}
+
+static inline void __delay(uint64_t cycles)
+{
+	uint64_t start = timer_get_cycles();
+
+	while ((timer_get_cycles() - start) < cycles)
+		cpu_relax();
+}
+
+static inline void udelay(unsigned long usec)
+{
+	__delay(usec_to_cycles(usec));
+}
+
+#endif /* SELFTEST_KVM_ARCH_TIMER_H */
diff --git a/tools/testing/selftests/kvm/include/riscv/processor.h b/tools/testing/selftests/kvm/include/riscv/processor.h
index 1b0a9e9d2d30..ce473fe251dd 100644
--- a/tools/testing/selftests/kvm/include/riscv/processor.h
+++ b/tools/testing/selftests/kvm/include/riscv/processor.h
@@ -193,4 +193,14 @@ struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0,
 
 bool guest_sbi_probe_extension(int extid, long *out_val);
 
+static inline void local_irq_enable(void)
+{
+	csr_set(CSR_SSTATUS, SR_SIE);
+}
+
+static inline void local_irq_disable(void)
+{
+	csr_clear(CSR_SSTATUS, SR_SIE);
+}
+
 #endif /* SELFTEST_KVM_PROCESSOR_H */