From 80166904655976bb9babc48fd283c2bba5799920 Mon Sep 17 00:00:00 2001 From: Raghavendra Rao Ananta Date: Thu, 7 Oct 2021 23:34:31 +0000 Subject: [PATCH] KVM: arm64: selftests: Add basic support to generate delays 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 Reviewed-by: Andrew Jones Reviewed-by: Oliver Upton Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20211007233439.1826892-8-rananta@google.com --- .../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 */ -- GitLab