s390/cpum_cf: Export event names in sysfs

Provide PMU event attributes for supported counters and export their symbolic
names to the sysfs "events" directory.

See the /sys/devices/cpum_cf/events/ directory for a list of available counters.
Note that you might require counter set authorizations for the LPAR to use them.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/include/asm/perf_event.h

 /*
  * Performance event support - s390 specific definitions.
  *
- * Copyright IBM Corp. 2009, 2012
+ * Copyright IBM Corp. 2009, 2013
  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
  *	      Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
  */
 
+#ifndef _ASM_S390_PERF_EVENT_H
+#define _ASM_S390_PERF_EVENT_H
+
+#ifdef CONFIG_64BIT
+
+#include <linux/perf_event.h>
+#include <linux/device.h>
 #include <asm/cpu_mf.h>
 
 /* CPU-measurement counter facility */
@@ -15,7 +22,18 @@
 #define PMU_F_RESERVED			0x1000
 #define PMU_F_ENABLED			0x2000
 
-#ifdef CONFIG_64BIT
+/* Perf defintions for PMU event attributes in sysfs */
+extern __init const struct attribute_group **cpumf_cf_event_group(void);
+extern ssize_t cpumf_events_sysfs_show(struct device *dev,
+				       struct device_attribute *attr,
+				       char *page);
+#define EVENT_VAR(_cat, _name)		event_attr_##_cat##_##_name
+#define EVENT_PTR(_cat, _name)		(&EVENT_VAR(_cat, _name).attr.attr)
+
+#define CPUMF_EVENT_ATTR(cat, name, id)			\
+	PMU_EVENT_ATTR(name, EVENT_VAR(cat, name), id, cpumf_events_sysfs_show)
+#define CPUMF_EVENT_PTR(cat, name)	EVENT_PTR(cat, name)
+
 
 /* Perf callbacks */
 struct pt_regs;
@@ -24,3 +42,4 @@ extern unsigned long perf_misc_flags(struct pt_regs *regs);
 #define perf_misc_flags(regs) perf_misc_flags(regs)
 
 #endif /* CONFIG_64BIT */
+#endif /* _ASM_S390_PERF_EVENT_H */

arch/s390/kernel/Makefile

@@ -60,7 +60,8 @@ obj-$(CONFIG_FTRACE_SYSCALLS)  += ftrace.o
 obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o
 
 ifdef CONFIG_64BIT
-obj-$(CONFIG_PERF_EVENTS)	+= perf_event.o perf_cpum_cf.o
+obj-$(CONFIG_PERF_EVENTS)	+= perf_event.o perf_cpum_cf.o \
+						perf_cpum_cf_events.o
 obj-y				+= runtime_instr.o cache.o
 endif
 

arch/s390/kernel/perf_cpum_cf.c

@@ -680,6 +680,7 @@ static int __init cpumf_pmu_init(void)
 		goto out;
 	}
 
+	cpumf_pmu.attr_groups = cpumf_cf_event_group();
 	rc = perf_pmu_register(&cpumf_pmu, "cpum_cf", PERF_TYPE_RAW);
 	if (rc) {
 		pr_err("Registering the cpum_cf PMU failed with rc=%i\n", rc);

arch/s390/kernel/perf_event.c

@@ -16,6 +16,7 @@
 #include <linux/kvm_host.h>
 #include <linux/percpu.h>
 #include <linux/export.h>
+#include <linux/sysfs.h>
 #include <asm/irq.h>
 #include <asm/cpu_mf.h>
 #include <asm/lowcore.h>
@@ -172,3 +173,14 @@ void perf_callchain_kernel(struct perf_callchain_entry *entry,
 	__store_trace(entry, head, S390_lowcore.thread_info,
 		      S390_lowcore.thread_info + THREAD_SIZE);
 }
+
+/* Perf defintions for PMU event attributes in sysfs */
+ssize_t cpumf_events_sysfs_show(struct device *dev,
+				struct device_attribute *attr, char *page)
+{
+	struct perf_pmu_events_attr *pmu_attr;
+
+	pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
+	return sprintf(page, "event=0x%04llx,name=%s\n",
+		       pmu_attr->id, attr->attr.name);
+}