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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/x86/tests/rdpmc.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/x86/tests/rdpmc.c')
-rw-r--r-- | tools/perf/arch/x86/tests/rdpmc.c | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/tools/perf/arch/x86/tests/rdpmc.c b/tools/perf/arch/x86/tests/rdpmc.c new file mode 100644 index 000000000..1ea916656 --- /dev/null +++ b/tools/perf/arch/x86/tests/rdpmc.c @@ -0,0 +1,182 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <errno.h> +#include <unistd.h> +#include <stdlib.h> +#include <signal.h> +#include <sys/mman.h> +#include <sys/types.h> +#include <sys/wait.h> +#include <linux/string.h> +#include <linux/types.h> +#include "perf-sys.h" +#include "debug.h" +#include "tests/tests.h" +#include "cloexec.h" +#include "event.h" +#include <internal/lib.h> // page_size +#include "arch-tests.h" + +static u64 rdpmc(unsigned int counter) +{ + unsigned int low, high; + + asm volatile("rdpmc" : "=a" (low), "=d" (high) : "c" (counter)); + + return low | ((u64)high) << 32; +} + +static u64 rdtsc(void) +{ + unsigned int low, high; + + asm volatile("rdtsc" : "=a" (low), "=d" (high)); + + return low | ((u64)high) << 32; +} + +static u64 mmap_read_self(void *addr) +{ + struct perf_event_mmap_page *pc = addr; + u32 seq, idx, time_mult = 0, time_shift = 0; + u64 count, cyc = 0, time_offset = 0, enabled, running, delta; + + do { + seq = pc->lock; + barrier(); + + enabled = pc->time_enabled; + running = pc->time_running; + + if (enabled != running) { + cyc = rdtsc(); + time_mult = pc->time_mult; + time_shift = pc->time_shift; + time_offset = pc->time_offset; + } + + idx = pc->index; + count = pc->offset; + if (idx) + count += rdpmc(idx - 1); + + barrier(); + } while (pc->lock != seq); + + if (enabled != running) { + u64 quot, rem; + + quot = (cyc >> time_shift); + rem = cyc & (((u64)1 << time_shift) - 1); + delta = time_offset + quot * time_mult + + ((rem * time_mult) >> time_shift); + + enabled += delta; + if (idx) + running += delta; + + quot = count / running; + rem = count % running; + count = quot * enabled + (rem * enabled) / running; + } + + return count; +} + +/* + * If the RDPMC instruction faults then signal this back to the test parent task: + */ +static void segfault_handler(int sig __maybe_unused, + siginfo_t *info __maybe_unused, + void *uc __maybe_unused) +{ + exit(-1); +} + +static int __test__rdpmc(void) +{ + volatile int tmp = 0; + u64 i, loops = 1000; + int n; + int fd; + void *addr; + struct perf_event_attr attr = { + .type = PERF_TYPE_HARDWARE, + .config = PERF_COUNT_HW_INSTRUCTIONS, + .exclude_kernel = 1, + }; + u64 delta_sum = 0; + struct sigaction sa; + char sbuf[STRERR_BUFSIZE]; + + sigfillset(&sa.sa_mask); + sa.sa_sigaction = segfault_handler; + sa.sa_flags = 0; + sigaction(SIGSEGV, &sa, NULL); + + fd = sys_perf_event_open(&attr, 0, -1, -1, + perf_event_open_cloexec_flag()); + if (fd < 0) { + pr_err("Error: sys_perf_event_open() syscall returned " + "with %d (%s)\n", fd, + str_error_r(errno, sbuf, sizeof(sbuf))); + return -1; + } + + addr = mmap(NULL, page_size, PROT_READ, MAP_SHARED, fd, 0); + if (addr == (void *)(-1)) { + pr_err("Error: mmap() syscall returned with (%s)\n", + str_error_r(errno, sbuf, sizeof(sbuf))); + goto out_close; + } + + for (n = 0; n < 6; n++) { + u64 stamp, now, delta; + + stamp = mmap_read_self(addr); + + for (i = 0; i < loops; i++) + tmp++; + + now = mmap_read_self(addr); + loops *= 10; + + delta = now - stamp; + pr_debug("%14d: %14Lu\n", n, (long long)delta); + + delta_sum += delta; + } + + munmap(addr, page_size); + pr_debug(" "); +out_close: + close(fd); + + if (!delta_sum) + return -1; + + return 0; +} + +int test__rdpmc(struct test *test __maybe_unused, int subtest __maybe_unused) +{ + int status = 0; + int wret = 0; + int ret; + int pid; + + pid = fork(); + if (pid < 0) + return -1; + + if (!pid) { + ret = __test__rdpmc(); + + exit(ret); + } + + wret = waitpid(pid, &status, 0); + if (wret < 0 || status) + return -1; + + return 0; +} |