s390/perf: add support for the CPU-Measurement Sampling Facility

Introduce a perf PMU, "cpum_sf", to support the CPU-Measurement
Sampling Facility.  You can control the sampling facility through
this perf PMU interfaces.  Perf sampling events are created for
hardware samples.

For details about the CPU-Measurement Sampling Facility, see
"The Load-Program-Parameter and the CPU-Measurement Facilities" (SA23-2260).

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/include/asm/cpu_mf.h

@@ -210,6 +210,20 @@ static inline int lsctl(struct hws_lsctl_request_block *req)
 
 /* Sampling control helper functions */
 
+#include <linux/time.h>
+
+static inline unsigned long freq_to_sample_rate(struct hws_qsi_info_block *qsi,
+						unsigned long freq)
+{
+	return (USEC_PER_SEC / freq) * qsi->cpu_speed;
+}
+
+static inline unsigned long sample_rate_to_freq(struct hws_qsi_info_block *qsi,
+						unsigned long rate)
+{
+	return USEC_PER_SEC * qsi->cpu_speed / rate;
+}
+
 #define SDB_TE_ALERT_REQ_MASK	0x4000000000000000UL
 #define SDB_TE_BUFFER_FULL_MASK 0x8000000000000000UL
 

arch/s390/include/asm/perf_event.h

@@ -15,12 +15,13 @@
 #include <linux/device.h>
 #include <asm/cpu_mf.h>
 
-/* CPU-measurement counter facility */
-#define PERF_CPUM_CF_MAX_CTR		256
-
 /* Per-CPU flags for PMU states */
 #define PMU_F_RESERVED			0x1000
 #define PMU_F_ENABLED			0x2000
+#define PMU_F_IN_USE			0x4000
+#define PMU_F_ERR_IBE			0x0100
+#define PMU_F_ERR_LSDA			0x0200
+#define PMU_F_ERR_MASK			(PMU_F_ERR_IBE|PMU_F_ERR_LSDA)
 
 /* Perf defintions for PMU event attributes in sysfs */
 extern __init const struct attribute_group **cpumf_cf_event_group(void);
@@ -41,5 +42,15 @@ extern unsigned long perf_instruction_pointer(struct pt_regs *regs);
 extern unsigned long perf_misc_flags(struct pt_regs *regs);
 #define perf_misc_flags(regs) perf_misc_flags(regs)
 
+/* Perf PMU definitions for the counter facility */
+#define PERF_CPUM_CF_MAX_CTR		256
+
+/* Perf PMU definitions for the sampling facility */
+#define PERF_CPUM_SF_MAX_CTR		1
+#define PERF_EVENT_CPUM_SF		0xB0000UL	/* Raw event ID */
+
+#define TEAR_REG(hwc)		((hwc)->last_tag)
+#define SAMPL_RATE(hwc)		((hwc)->event_base)
+
 #endif /* CONFIG_64BIT */
 #endif /* _ASM_S390_PERF_EVENT_H */

arch/s390/kernel/Makefile

@@ -60,7 +60,7 @@ 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_sf.o \
 						perf_cpum_cf_events.o
 obj-y				+= runtime_instr.o cache.o
 endif