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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
commit | 76cb841cb886eef6b3bee341a2266c76578724ad (patch) | |
tree | f5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /tools/perf/arch/x86/util/tsc.c | |
parent | Initial commit. (diff) | |
download | linux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip |
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/perf/arch/x86/util/tsc.c')
-rw-r--r-- | tools/perf/arch/x86/util/tsc.c | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/tools/perf/arch/x86/util/tsc.c b/tools/perf/arch/x86/util/tsc.c new file mode 100644 index 000000000..950539f9a --- /dev/null +++ b/tools/perf/arch/x86/util/tsc.c @@ -0,0 +1,82 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <stdbool.h> +#include <errno.h> + +#include <linux/stddef.h> +#include <linux/perf_event.h> + +#include "../../perf.h" +#include <linux/types.h> +#include "../../util/debug.h" +#include "../../util/tsc.h" + +int perf_read_tsc_conversion(const struct perf_event_mmap_page *pc, + struct perf_tsc_conversion *tc) +{ + bool cap_user_time_zero; + u32 seq; + int i = 0; + + while (1) { + seq = pc->lock; + rmb(); + tc->time_mult = pc->time_mult; + tc->time_shift = pc->time_shift; + tc->time_zero = pc->time_zero; + cap_user_time_zero = pc->cap_user_time_zero; + rmb(); + if (pc->lock == seq && !(seq & 1)) + break; + if (++i > 10000) { + pr_debug("failed to get perf_event_mmap_page lock\n"); + return -EINVAL; + } + } + + if (!cap_user_time_zero) + return -EOPNOTSUPP; + + return 0; +} + +u64 rdtsc(void) +{ + unsigned int low, high; + + asm volatile("rdtsc" : "=a" (low), "=d" (high)); + + return low | ((u64)high) << 32; +} + +int perf_event__synth_time_conv(const struct perf_event_mmap_page *pc, + struct perf_tool *tool, + perf_event__handler_t process, + struct machine *machine) +{ + union perf_event event = { + .time_conv = { + .header = { + .type = PERF_RECORD_TIME_CONV, + .size = sizeof(struct time_conv_event), + }, + }, + }; + struct perf_tsc_conversion tc; + int err; + + if (!pc) + return 0; + err = perf_read_tsc_conversion(pc, &tc); + if (err == -EOPNOTSUPP) + return 0; + if (err) + return err; + + pr_debug2("Synthesizing TSC conversion information\n"); + + event.time_conv.time_mult = tc.time_mult; + event.time_conv.time_shift = tc.time_shift; + event.time_conv.time_zero = tc.time_zero; + + return process(tool, &event, NULL, machine); +} |