perf pmu: Push configuration down to PMU driver

This patch adds a PMU callback and the required mechanic so that drivers
can process the command line configuration elements found in
evsel::config_terms.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1474041004-13956-6-git-send-email-mathieu.poirier@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/Build

@@ -86,6 +86,7 @@ libperf-y += term.o
 libperf-y += help-unknown-cmd.o
 libperf-y += mem-events.o
 libperf-y += vsprintf.o
+libperf-y += drv_configs.o
 
 libperf-$(CONFIG_LIBBPF) += bpf-loader.o
 libperf-$(CONFIG_BPF_PROLOGUE) += bpf-prologue.o

tools/perf/util/drv_configs.c

@@ -0,0 +1,77 @@
+/*
+ * drv_configs.h: Interface to apply PMU specific configuration
+ * Copyright (c) 2016-2018, Linaro Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ */
+
+#include "drv_configs.h"
+#include "evlist.h"
+#include "evsel.h"
+#include "pmu.h"
+
+static int
+perf_evsel__apply_drv_configs(struct perf_evsel *evsel,
+			      struct perf_evsel_config_term **err_term)
+{
+	bool found = false;
+	int err = 0;
+	struct perf_evsel_config_term *term;
+	struct perf_pmu *pmu = NULL;
+
+	while ((pmu = perf_pmu__scan(pmu)) != NULL)
+		if (pmu->type == evsel->attr.type) {
+			found = true;
+			break;
+		}
+
+	list_for_each_entry(term, &evsel->config_terms, list) {
+		if (term->type != PERF_EVSEL__CONFIG_TERM_DRV_CFG)
+			continue;
+
+		/*
+		 * We have a configuration term, report an error if we
+		 * can't find the PMU or if the PMU driver doesn't support
+		 * cmd line driver configuration.
+		 */
+		if (!found || !pmu->set_drv_config) {
+			err = -EINVAL;
+			*err_term = term;
+			break;
+		}
+
+		err = pmu->set_drv_config(term);
+		if (err) {
+			*err_term = term;
+			break;
+		}
+	}
+
+	return err;
+}
+
+int perf_evlist__apply_drv_configs(struct perf_evlist *evlist,
+				   struct perf_evsel **err_evsel,
+				   struct perf_evsel_config_term **err_term)
+{
+	struct perf_evsel *evsel;
+	int err = 0;
+
+	evlist__for_each_entry(evlist, evsel) {
+		err = perf_evsel__apply_drv_configs(evsel, err_term);
+		if (err) {
+			*err_evsel = evsel;
+			break;
+		}
+	}
+
+	return err;
+}

tools/perf/util/drv_configs.h

@@ -0,0 +1,26 @@
+/*
+ * drv_configs.h: Interface to apply PMU specific configuration
+ * Copyright (c) 2016-2018, Linaro Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ */
+
+#ifndef __PERF_DRV_CONFIGS_H
+#define __PERF_DRV_CONFIGS_H
+
+#include "drv_configs.h"
+#include "evlist.h"
+#include "evsel.h"
+
+int perf_evlist__apply_drv_configs(struct perf_evlist *evlist,
+				   struct perf_evsel **err_evsel,
+				   struct perf_evsel_config_term **term);
+#endif

tools/perf/util/pmu.h

@@ -4,6 +4,7 @@
 #include <linux/bitmap.h>
 #include <linux/perf_event.h>
 #include <stdbool.h>
+#include "evsel.h"
 #include "parse-events.h"
 
 enum {
@@ -25,6 +26,7 @@ struct perf_pmu {
 	struct list_head format;  /* HEAD struct perf_pmu_format -> list */
 	struct list_head aliases; /* HEAD struct perf_pmu_alias -> list */
 	struct list_head list;    /* ELEM */
+	int (*set_drv_config)	(struct perf_evsel_config_term *term);
 };
 
 struct perf_pmu_info {