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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /tools/perf/arch/arm64/util/tsc.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/perf/arch/arm64/util/tsc.c')
-rw-r--r-- | tools/perf/arch/arm64/util/tsc.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/tools/perf/arch/arm64/util/tsc.c b/tools/perf/arch/arm64/util/tsc.c new file mode 100644 index 000000000..cc85bd9e7 --- /dev/null +++ b/tools/perf/arch/arm64/util/tsc.c @@ -0,0 +1,21 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/types.h> + +#include "../../../util/tsc.h" + +u64 rdtsc(void) +{ + u64 val; + + /* + * According to ARM DDI 0487F.c, from Armv8.0 to Armv8.5 inclusive, the + * system counter is at least 56 bits wide; from Armv8.6, the counter + * must be 64 bits wide. So the system counter could be less than 64 + * bits wide and it is attributed with the flag 'cap_user_time_short' + * is true. + */ + asm volatile("mrs %0, cntvct_el0" : "=r" (val)); + + return val; +} |