RISC-V: Support CPUID for risc-v in perf

This patch creates the header.c file for the risc-v architecture and introduces support for
PMU identification through sysfs.
It is now possible to configure pmu-events in risc-v.

Depends on patch [1], that introduces the id sysfs file.

Signed-off-by: João Mário Domingos <joao.mario@tecnico.ulisboa.pt>
Signed-off-by: minda.chen <minda.chen@starfivetech.com>

diff --git a/drivers/perf/riscv_pmu.c b/drivers/perf/riscv_pmu.c
index b2b8d20..d1aa4e0 100644 (file)
--- a/drivers/perf/riscv_pmu.c
+++ b/drivers/perf/riscv_pmu.c
@@ -17,6 +17,23 @@
 
 #include <asm/sbi.h>
 
+PMU_FORMAT_ATTR(event, "config:0-63");
+
+static struct attribute *riscv_arch_formats_attr[] = {
+       &format_attr_event.attr,
+       NULL,
+};
+
+static struct attribute_group riscv_pmu_format_group = {
+       .name = "format",
+       .attrs = riscv_arch_formats_attr,
+};
+
+static const struct attribute_group *riscv_pmu_attr_groups[] = {
+       &riscv_pmu_format_group,
+       NULL,
+};
+
 static unsigned long csr_read_num(int csr_num)
 {
 #define switchcase_csr_read(__csr_num, __val)          {\
@@ -307,6 +324,7 @@ struct riscv_pmu *riscv_pmu_alloc(void)
                        cpuc->events[i] = NULL;
        }
        pmu->pmu = (struct pmu) {
+               .attr_groups    = riscv_pmu_attr_groups,
                .event_init     = riscv_pmu_event_init,
                .add            = riscv_pmu_add,
                .del            = riscv_pmu_del,

diff --git a/tools/perf/arch/riscv/util/Build b/tools/perf/arch/riscv/util/Build
index 7d30501..603dbb5 100644 (file)
--- a/tools/perf/arch/riscv/util/Build
+++ b/tools/perf/arch/riscv/util/Build
@@ -1,4 +1,5 @@
 perf-y += perf_regs.o
+perf-y += header.o
 
 perf-$(CONFIG_DWARF) += dwarf-regs.o
 perf-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o

diff --git a/tools/perf/arch/riscv/util/header.c b/tools/perf/arch/riscv/util/header.c
new file mode 100644 (file)
index 0000000..98d40b8
--- /dev/null
+++ b/tools/perf/arch/riscv/util/header.c
@@ -0,0 +1,66 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <api/fs/fs.h>
+#include <errno.h>
+#include "../../util/debug.h"
+#include "../../util/header.h"
+
+#define STR_LEN 1024
+#define ID_SIZE 64
+
+static int _get_cpuid(char *buf, size_t sz)
+{
+       const char *sysfs = sysfs__mountpoint();
+       u64 id = 0;
+       char path[PATH_MAX];
+       FILE *file;
+
+       if (!sysfs || sz < ID_SIZE)
+               return -EINVAL;
+
+       scnprintf(path, PATH_MAX, "%s/devices/platform/riscv-pmu/id",
+                       sysfs);
+
+       file = fopen(path, "r");
+       if (!file) {
+               pr_debug("fopen failed for file %s\n", path);
+               return -EINVAL;
+       }
+       if (!fgets(buf, ID_SIZE, file)) {
+               fclose(file);
+               return -EINVAL;
+       }
+
+       fclose(file);
+
+       /*Check if value is numeric and remove special characters*/
+       id = strtoul(buf, NULL, 16);
+       if (!id)
+               return -EINVAL;
+       scnprintf(buf, ID_SIZE, "0x%lx", id);
+
+       return 0;
+}
+
+char *get_cpuid_str(struct perf_pmu *pmu __maybe_unused)
+{
+       char *buf = NULL;
+       int res;
+
+       if (!pmu)
+               return NULL;
+
+       buf = malloc(ID_SIZE);
+       if (!buf)
+               return NULL;
+
+       /* read id */
+       res = _get_cpuid(buf, ID_SIZE);
+       if (res) {
+               pr_err("failed to get cpuid string for PMU %s\n", pmu->name);
+               free(buf);
+               buf = NULL;
+       }
+
+       return buf;
+}