[PATCH v4 07/18] KVM: arm64: selftests: Add basic support to generate delays
From: Raghavendra Rao Ananta <hidden>
Date: 2021-09-09 01:38:55
Also in:
kvm, kvmarm, lkml
Subsystem:
kernel selftest framework, kernel virtual machine (kvm), the rest · Maintainers:
Shuah Khan, Paolo Bonzini, Linus Torvalds
Add udelay() support to generate a delay in the guest. The routines are derived and simplified from kernel's arch/arm64/lib/delay.c. Signed-off-by: Raghavendra Rao Ananta <redacted> Reviewed-by: Andrew Jones <redacted> Reviewed-by: Oliver Upton <redacted> --- .../selftests/kvm/include/aarch64/delay.h | 25 +++++++++++++++++++ 1 file changed, 25 insertions(+) create mode 100644 tools/testing/selftests/kvm/include/aarch64/delay.h
diff --git a/tools/testing/selftests/kvm/include/aarch64/delay.h b/tools/testing/selftests/kvm/include/aarch64/delay.h
new file mode 100644
index 000000000000..329e4f5079ea
--- /dev/null
+++ b/tools/testing/selftests/kvm/include/aarch64/delay.h@@ -0,0 +1,25 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * ARM simple delay routines + */ + +#ifndef SELFTEST_KVM_ARM_DELAY_H +#define SELFTEST_KVM_ARM_DELAY_H + +#include "arch_timer.h" + +static inline void __delay(uint64_t cycles) +{ + enum arch_timer timer = VIRTUAL; + uint64_t start = timer_get_cntct(timer); + + while ((timer_get_cntct(timer) - start) < cycles) + cpu_relax(); +} + +static inline void udelay(unsigned long usec) +{ + __delay(usec_to_cycles(usec)); +} + +#endif /* SELFTEST_KVM_ARM_DELAY_H */
--
2.33.0.153.gba50c8fa24-goog
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