diff options
Diffstat (limited to 'tools')
-rw-r--r-- | tools/perf/arch/arm64/util/Build | 1 | ||||
-rw-r--r-- | tools/perf/arch/arm64/util/tsc.c | 21 |
2 files changed, 22 insertions, 0 deletions
diff --git a/tools/perf/arch/arm64/util/Build b/tools/perf/arch/arm64/util/Build index 5c13438c7bd4..b53294d74b01 100644 --- a/tools/perf/arch/arm64/util/Build +++ b/tools/perf/arch/arm64/util/Build @@ -1,6 +1,7 @@ perf-y += header.o perf-y += machine.o perf-y += perf_regs.o +perf-y += tsc.o perf-$(CONFIG_DWARF) += dwarf-regs.o perf-$(CONFIG_LOCAL_LIBUNWIND) += unwind-libunwind.o perf-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o diff --git a/tools/perf/arch/arm64/util/tsc.c b/tools/perf/arch/arm64/util/tsc.c new file mode 100644 index 000000000000..cc85bd9e73f1 --- /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; +} |