perf tools: Add perf pmu object to access pmu format definition

Adding pmu object which provides interface to pmu's sysfs
event format definition located at:
  ${sysfs_mount}/bus/event_source/devices/${pmu}/format

Following interface is exported:
  struct perf_pmu* perf_pmu__find(char *name);
  - this function returns pmu object, which is then
    passed as a handle to other interface functions

  int perf_pmu__config(struct perf_pmu *pmu, struct perf_event_attr *attr,
                       struct list_head *head_terms);
  - this function configures perf_event_attr struct based
    on pmu's format definitions and config terms data,
    containined in head_terms list.

Parser generator is used to retrive the pmu's format definition.
The generated parser is part of the patch. Added makefile rule
'pmu-parser' to generate the parser code out of the bison/flex
sources.

Added builtin test 'Test perf pmu format parsing', which could
be run like:
	perf test pmu

Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/n/tip-errz96u1668gj9wlop1zhpht@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 469 insertions, 0 deletions

diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
new file mode 100644
index 000000000000..cb08a118e811
--- /dev/null
+++ b/tools/perf/util/pmu.c
@@ -0,0 +1,469 @@
+
+#include <linux/list.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <dirent.h>
+#include "sysfs.h"
+#include "util.h"
+#include "pmu.h"
+#include "parse-events.h"
+
+int perf_pmu_parse(struct list_head *list, char *name);
+extern FILE *perf_pmu_in;
+
+static LIST_HEAD(pmus);
+
+/*
+ * Parse & process all the sysfs attributes located under
+ * the directory specified in 'dir' parameter.
+ */
+static int pmu_format_parse(char *dir, struct list_head *head)
+{
+        struct dirent *evt_ent;
+        DIR *format_dir;
+        int ret = 0;
+
+        format_dir = opendir(dir);
+        if (!format_dir)
+                return -EINVAL;
+
+        while (!ret && (evt_ent = readdir(format_dir))) {
+                char path[PATH_MAX];
+                char *name = evt_ent->d_name;
+                FILE *file;
+
+                if (!strcmp(name, ".") || !strcmp(name, ".."))
+                        continue;
+
+                snprintf(path, PATH_MAX, "%s/%s", dir, name);
+
+                ret = -EINVAL;
+                file = fopen(path, "r");
+                if (!file)
+                        break;
+
+                perf_pmu_in = file;
+                ret = perf_pmu_parse(head, name);
+                fclose(file);
+        }
+
+        closedir(format_dir);
+        return ret;
+}
+
+/*
+ * Reading/parsing the default pmu format definition, which should be
+ * located at:
+ * /sys/bus/event_source/devices/<dev>/format as sysfs group attributes.
+ */
+static int pmu_format(char *name, struct list_head *format)
+{
+        struct stat st;
+        char path[PATH_MAX];
+        const char *sysfs;
+
+        sysfs = sysfs_find_mountpoint();
+        if (!sysfs)
+                return -1;
+
+        snprintf(path, PATH_MAX,
+                 "%s/bus/event_source/devices/%s/format", sysfs, name);
+
+        if (stat(path, &st) < 0)
+                return -1;
+
+        if (pmu_format_parse(path, format))
+                return -1;
+
+        return 0;
+}
+
+/*
+ * Reading/parsing the default pmu type value, which should be
+ * located at:
+ * /sys/bus/event_source/devices/<dev>/type as sysfs attribute.
+ */
+static int pmu_type(char *name, __u32 *type)
+{
+        struct stat st;
+        char path[PATH_MAX];
+        const char *sysfs;
+        FILE *file;
+        int ret = 0;
+
+        sysfs = sysfs_find_mountpoint();
+        if (!sysfs)
+                return -1;
+
+        snprintf(path, PATH_MAX,
+                 "%s/bus/event_source/devices/%s/type", sysfs, name);
+
+        if (stat(path, &st) < 0)
+                return -1;
+
+        file = fopen(path, "r");
+        if (!file)
+                return -EINVAL;
+
+        if (1 != fscanf(file, "%u", type))
+                ret = -1;
+
+        fclose(file);
+        return ret;
+}
+
+static struct perf_pmu *pmu_lookup(char *name)
+{
+        struct perf_pmu *pmu;
+        LIST_HEAD(format);
+        __u32 type;
+
+        /*
+         * The pmu data we store & need consists of the pmu
+         * type value and format definitions. Load both right
+         * now.
+         */
+        if (pmu_format(name, &format))
+                return NULL;
+
+        if (pmu_type(name, &type))
+                return NULL;
+
+        pmu = zalloc(sizeof(*pmu));
+        if (!pmu)
+                return NULL;
+
+        INIT_LIST_HEAD(&pmu->format);
+        list_splice(&format, &pmu->format);
+        pmu->name = strdup(name);
+        pmu->type = type;
+        return pmu;
+}
+
+static struct perf_pmu *pmu_find(char *name)
+{
+        struct perf_pmu *pmu;
+
+        list_for_each_entry(pmu, &pmus, list)
+                if (!strcmp(pmu->name, name))
+                        return pmu;
+
+        return NULL;
+}
+
+struct perf_pmu *perf_pmu__find(char *name)
+{
+        struct perf_pmu *pmu;
+
+        /*
+         * Once PMU is loaded it stays in the list,
+         * so we keep us from multiple reading/parsing
+         * the pmu format definitions.
+         */
+        pmu = pmu_find(name);
+        if (pmu)
+                return pmu;
+
+        return pmu_lookup(name);
+}
+
+static struct perf_pmu__format*
+pmu_find_format(struct list_head *formats, char *name)
+{
+        struct perf_pmu__format *format;
+
+        list_for_each_entry(format, formats, list)
+                if (!strcmp(format->name, name))
+                        return format;
+
+        return NULL;
+}
+
+/*
+ * Returns value based on the format definition (format parameter)
+ * and unformated value (value parameter).
+ *
+ * TODO maybe optimize a little ;)
+ */
+static __u64 pmu_format_value(unsigned long *format, __u64 value)
+{
+        unsigned long fbit, vbit;
+        __u64 v = 0;
+
+        for (fbit = 0, vbit = 0; fbit < PERF_PMU_FORMAT_BITS; fbit++) {
+
+                if (!test_bit(fbit, format))
+                        continue;
+
+                if (!(value & (1llu << vbit++)))
+                        continue;
+
+                v |= (1llu << fbit);
+        }
+
+        return v;
+}
+
+/*
+ * Setup one of config[12] attr members based on the
+ * user input data - temr parameter.
+ */
+static int pmu_config_term(struct list_head *formats,
+                           struct perf_event_attr *attr,
+                           struct parse_events__term *term)
+{
+        struct perf_pmu__format *format;
+        __u64 *vp;
+
+        /*
+         * Support only for hardcoded and numnerial terms.
+         * Hardcoded terms should be already in, so nothing
+         * to be done for them.
+         */
+        if (parse_events__is_hardcoded_term(term))
+                return 0;
+
+        if (term->type != PARSE_EVENTS__TERM_TYPE_NUM)
+                return -EINVAL;
+
+        format = pmu_find_format(formats, term->config);
+        if (!format)
+                return -EINVAL;
+
+        switch (format->value) {
+        case PERF_PMU_FORMAT_VALUE_CONFIG:
+                vp = &attr->config;
+                break;
+        case PERF_PMU_FORMAT_VALUE_CONFIG1:
+                vp = &attr->config1;
+                break;
+        case PERF_PMU_FORMAT_VALUE_CONFIG2:
+                vp = &attr->config2;
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        *vp |= pmu_format_value(format->bits, term->val.num);
+        return 0;
+}
+
+static int pmu_config(struct list_head *formats, struct perf_event_attr *attr,
+                      struct list_head *head_terms)
+{
+        struct parse_events__term *term, *h;
+
+        list_for_each_entry_safe(term, h, head_terms, list)
+                if (pmu_config_term(formats, attr, term))
+                        return -EINVAL;
+
+        return 0;
+}
+
+/*
+ * Configures event's 'attr' parameter based on the:
+ * 1) users input - specified in terms parameter
+ * 2) pmu format definitions - specified by pmu parameter
+ */
+int perf_pmu__config(struct perf_pmu *pmu, struct perf_event_attr *attr,
+                     struct list_head *head_terms)
+{
+        attr->type = pmu->type;
+        return pmu_config(&pmu->format, attr, head_terms);
+}
+
+int perf_pmu__new_format(struct list_head *list, char *name,
+                         int config, unsigned long *bits)
+{
+        struct perf_pmu__format *format;
+
+        format = zalloc(sizeof(*format));
+        if (!format)
+                return -ENOMEM;
+
+        format->name = strdup(name);
+        format->value = config;
+        memcpy(format->bits, bits, sizeof(format->bits));
+
+        list_add_tail(&format->list, list);
+        return 0;
+}
+
+void perf_pmu__set_format(unsigned long *bits, long from, long to)
+{
+        long b;
+
+        if (!to)
+                to = from;
+
+        memset(bits, 0, BITS_TO_LONGS(PERF_PMU_FORMAT_BITS));
+        for (b = from; b <= to; b++)
+                set_bit(b, bits);
+}
+
+/* Simulated format definitions. */
+static struct test_format {
+        const char *name;
+        const char *value;
+} test_formats[] = {
+        { "krava01", "config:0-1,62-63\n", },
+        { "krava02", "config:10-17\n", },
+        { "krava03", "config:5\n", },
+        { "krava11", "config1:0,2,4,6,8,20-28\n", },
+        { "krava12", "config1:63\n", },
+        { "krava13", "config1:45-47\n", },
+        { "krava21", "config2:0-3,10-13,20-23,30-33,40-43,50-53,60-63\n", },
+        { "krava22", "config2:8,18,48,58\n", },
+        { "krava23", "config2:28-29,38\n", },
+};
+
+#define TEST_FORMATS_CNT (sizeof(test_formats) / sizeof(struct test_format))
+
+/* Simulated users input. */
+static struct parse_events__term test_terms[] = {
+        {
+                .config  = (char *) "krava01",
+                .val.num = 15,
+                .type    = PARSE_EVENTS__TERM_TYPE_NUM,
+        },
+        {
+                .config  = (char *) "krava02",
+                .val.num = 170,
+                .type    = PARSE_EVENTS__TERM_TYPE_NUM,
+        },
+        {
+                .config  = (char *) "krava03",
+                .val.num = 1,
+                .type    = PARSE_EVENTS__TERM_TYPE_NUM,
+        },
+        {
+                .config  = (char *) "krava11",
+                .val.num = 27,
+                .type    = PARSE_EVENTS__TERM_TYPE_NUM,
+        },
+        {
+                .config  = (char *) "krava12",
+                .val.num = 1,
+                .type    = PARSE_EVENTS__TERM_TYPE_NUM,
+        },
+        {
+                .config  = (char *) "krava13",
+                .val.num = 2,
+                .type    = PARSE_EVENTS__TERM_TYPE_NUM,
+        },
+        {
+                .config  = (char *) "krava21",
+                .val.num = 119,
+                .type    = PARSE_EVENTS__TERM_TYPE_NUM,
+        },
+        {
+                .config  = (char *) "krava22",
+                .val.num = 11,
+                .type    = PARSE_EVENTS__TERM_TYPE_NUM,
+        },
+        {
+                .config  = (char *) "krava23",
+                .val.num = 2,
+                .type    = PARSE_EVENTS__TERM_TYPE_NUM,
+        },
+};
+#define TERMS_CNT (sizeof(test_terms) / sizeof(struct parse_events__term))
+
+/*
+ * Prepare format directory data, exported by kernel
+ * at /sys/bus/event_source/devices/<dev>/format.
+ */
+static char *test_format_dir_get(void)
+{
+        static char dir[PATH_MAX];
+        unsigned int i;
+
+        snprintf(dir, PATH_MAX, "/tmp/perf-pmu-test-format-XXXXXX");
+        if (!mkdtemp(dir))
+                return NULL;
+
+        for (i = 0; i < TEST_FORMATS_CNT; i++) {
+                static char name[PATH_MAX];
+                struct test_format *format = &test_formats[i];
+                FILE *file;
+
+                snprintf(name, PATH_MAX, "%s/%s", dir, format->name);
+
+                file = fopen(name, "w");
+                if (!file)
+                        return NULL;
+
+                if (1 != fwrite(format->value, strlen(format->value), 1, file))
+                        break;
+
+                fclose(file);
+        }
+
+        return dir;
+}
+
+/* Cleanup format directory. */
+static int test_format_dir_put(char *dir)
+{
+        char buf[PATH_MAX];
+        snprintf(buf, PATH_MAX, "rm -f %s/*\n", dir);
+        if (system(buf))
+                return -1;
+
+        snprintf(buf, PATH_MAX, "rmdir %s\n", dir);
+        return system(buf);
+}
+
+static struct list_head *test_terms_list(void)
+{
+        static LIST_HEAD(terms);
+        unsigned int i;
+
+        for (i = 0; i < TERMS_CNT; i++)
+                list_add_tail(&test_terms[i].list, &terms);
+
+        return &terms;
+}
+
+#undef TERMS_CNT
+
+int perf_pmu__test(void)
+{
+        char *format = test_format_dir_get();
+        LIST_HEAD(formats);
+        struct list_head *terms = test_terms_list();
+        int ret;
+
+        if (!format)
+                return -EINVAL;
+
+        do {
+                struct perf_event_attr attr;
+
+                memset(&attr, 0, sizeof(attr));
+
+                ret = pmu_format_parse(format, &formats);
+                if (ret)
+                        break;
+
+                ret = pmu_config(&formats, &attr, terms);
+                if (ret)
+                        break;
+
+                ret = -EINVAL;
+
+                if (attr.config  != 0xc00000000002a823)
+                        break;
+                if (attr.config1 != 0x8000400000000145)
+                        break;
+                if (attr.config2 != 0x0400000020041d07)
+                        break;
+
+                ret = 0;
+        } while (0);
+
+        test_format_dir_put(format);
+        return ret;
+}