perf tools arm64: Add support for get_cpuid_str function.

BugLink: https://bugs.launchpad.net/bugs/1747523
The get_cpuid_str function returns the MIDR string of the first online
cpu from the range of cpus associated with the PMU CORE device.

Signed-off-by: Ganapatrao Kulkarni <ganapatrao.kulkarni@cavium.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ganapatrao Kulkarni <gklkml16@gmail.com>
Cc: Jayachandran C <jnair@caviumnetworks.com>
Cc: Jonathan Cameron <jonathan.cameron@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robert Richter <robert.richter@cavium.com>
Cc: Shaokun Zhang <zhangshaokun@hisilicon.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/20171016183222.25750-3-ganapatrao.kulkarni@cavium.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
(cherry picked from commit b57df28893543db3466172088786fae39b7fc3ad)
Signed-off-by: dann frazier <dann.frazier@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/tools/perf/arch/arm64/util/Build b/tools/perf/arch/arm64/util/Build
index cef6fb38d17ebc7fdc5cc867758a43276f11617e..b1ab72d2a42e370b852442390bfd5bebcba7b987 100644 (file)
--- a/tools/perf/arch/arm64/util/Build
+++ b/tools/perf/arch/arm64/util/Build
@@ -1,3 +1,4 @@
+libperf-y += header.o
 libperf-$(CONFIG_DWARF)     += dwarf-regs.o
 libperf-$(CONFIG_LOCAL_LIBUNWIND) += unwind-libunwind.o
 

diff --git a/tools/perf/arch/arm64/util/header.c b/tools/perf/arch/arm64/util/header.c
new file mode 100644 (file)
index 0000000..534cd25
--- /dev/null
+++ b/tools/perf/arch/arm64/util/header.c
@@ -0,0 +1,65 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <api/fs/fs.h>
+#include "header.h"
+
+#define MIDR "/regs/identification/midr_el1"
+#define MIDR_SIZE 19
+#define MIDR_REVISION_MASK      0xf
+#define MIDR_VARIANT_SHIFT      20
+#define MIDR_VARIANT_MASK       (0xf << MIDR_VARIANT_SHIFT)
+
+char *get_cpuid_str(struct perf_pmu *pmu)
+{
+       char *buf = NULL;
+       char path[PATH_MAX];
+       const char *sysfs = sysfs__mountpoint();
+       int cpu;
+       u64 midr = 0;
+       struct cpu_map *cpus;
+       FILE *file;
+
+       if (!sysfs || !pmu || !pmu->cpus)
+               return NULL;
+
+       buf = malloc(MIDR_SIZE);
+       if (!buf)
+               return NULL;
+
+       /* read midr from list of cpus mapped to this pmu */
+       cpus = cpu_map__get(pmu->cpus);
+       for (cpu = 0; cpu < cpus->nr; cpu++) {
+               scnprintf(path, PATH_MAX, "%s/devices/system/cpu/cpu%d"MIDR,
+                               sysfs, cpus->map[cpu]);
+
+               file = fopen(path, "r");
+               if (!file) {
+                       pr_debug("fopen failed for file %s\n", path);
+                       continue;
+               }
+
+               if (!fgets(buf, MIDR_SIZE, file)) {
+                       fclose(file);
+                       continue;
+               }
+               fclose(file);
+
+               /* Ignore/clear Variant[23:20] and
+                * Revision[3:0] of MIDR
+                */
+               midr = strtoul(buf, NULL, 16);
+               midr &= (~(MIDR_VARIANT_MASK | MIDR_REVISION_MASK));
+               scnprintf(buf, MIDR_SIZE, "0x%016lx", midr);
+               /* got midr break loop */
+               break;
+       }
+
+       if (!midr) {
+               pr_err("failed to get cpuid string for PMU %s\n", pmu->name);
+               free(buf);
+               buf = NULL;
+       }
+
+       cpu_map__put(cpus);
+       return buf;
+}