s390/cpum_cf: add support for the MT-diagnostic counter set (z13)

Complete the IBM z13 support and support counters from the
MT-diagnostic counter set.  Note that this counter set is
available only if SMT is enabled.
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

@@ -20,9 +20,11 @@
 #define CPU_MF_INT_SF_PRA	(1 << 29)	/* program request alert */
 #define CPU_MF_INT_SF_SACA	(1 << 23)	/* sampler auth. change alert */
 #define CPU_MF_INT_SF_LSDA	(1 << 22)	/* loss of sample data alert */
+#define CPU_MF_INT_CF_MTDA	(1 << 15)	/* loss of MT ctr. data alert */
 #define CPU_MF_INT_CF_CACA	(1 <<  7)	/* counter auth. change alert */
 #define CPU_MF_INT_CF_LCDA	(1 <<  6)	/* loss of counter data alert */
-#define CPU_MF_INT_CF_MASK	(CPU_MF_INT_CF_CACA|CPU_MF_INT_CF_LCDA)
+#define CPU_MF_INT_CF_MASK	(CPU_MF_INT_CF_MTDA|CPU_MF_INT_CF_CACA| \
+				 CPU_MF_INT_CF_LCDA)
 #define CPU_MF_INT_SF_MASK	(CPU_MF_INT_SF_IAE|CPU_MF_INT_SF_ISE|	\
 				 CPU_MF_INT_SF_PRA|CPU_MF_INT_SF_SACA|	\
 				 CPU_MF_INT_SF_LSDA)

arch/s390/kernel/perf_cpum_cf.c

@@ -22,19 +22,12 @@
 #include <asm/irq.h>
 #include <asm/cpu_mf.h>
 
-/* CPU-measurement counter facility supports these CPU counter sets:
- * For CPU counter sets:
- *    Basic counter set:	     0-31
- *    Problem-state counter set:    32-63
- *    Crypto-activity counter set:  64-127
- *    Extented counter set:	   128-159
- */
 enum cpumf_ctr_set {
-	/* CPU counter sets */
-	CPUMF_CTR_SET_BASIC   = 0,
-	CPUMF_CTR_SET_USER    = 1,
-	CPUMF_CTR_SET_CRYPTO  = 2,
-	CPUMF_CTR_SET_EXT     = 3,
+	CPUMF_CTR_SET_BASIC   = 0,    /* Basic Counter Set */
+	CPUMF_CTR_SET_USER    = 1,    /* Problem-State Counter Set */
+	CPUMF_CTR_SET_CRYPTO  = 2,    /* Crypto-Activity Counter Set */
+	CPUMF_CTR_SET_EXT     = 3,    /* Extended Counter Set */
+	CPUMF_CTR_SET_MT_DIAG = 4,    /* MT-diagnostic Counter Set */
 
 	/* Maximum number of counter sets */
 	CPUMF_CTR_SET_MAX,
@@ -47,6 +40,7 @@ static const u64 cpumf_state_ctl[CPUMF_CTR_SET_MAX] = {
 	[CPUMF_CTR_SET_USER]	= 0x04,
 	[CPUMF_CTR_SET_CRYPTO]	= 0x08,
 	[CPUMF_CTR_SET_EXT]	= 0x01,
+	[CPUMF_CTR_SET_MT_DIAG] = 0x20,
 };
 
 static void ctr_set_enable(u64 *state, int ctr_set)
@@ -76,19 +70,20 @@ struct cpu_hw_events {
 };
 static DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events) = {
 	.ctr_set = {
-		[CPUMF_CTR_SET_BASIC]  = ATOMIC_INIT(0),
-		[CPUMF_CTR_SET_USER]   = ATOMIC_INIT(0),
-		[CPUMF_CTR_SET_CRYPTO] = ATOMIC_INIT(0),
-		[CPUMF_CTR_SET_EXT]    = ATOMIC_INIT(0),
+		[CPUMF_CTR_SET_BASIC]	= ATOMIC_INIT(0),
+		[CPUMF_CTR_SET_USER]	= ATOMIC_INIT(0),
+		[CPUMF_CTR_SET_CRYPTO]	= ATOMIC_INIT(0),
+		[CPUMF_CTR_SET_EXT]	= ATOMIC_INIT(0),
+		[CPUMF_CTR_SET_MT_DIAG] = ATOMIC_INIT(0),
 	},
 	.state = 0,
 	.flags = 0,
 	.txn_flags = 0,
 };
 
-static int get_counter_set(u64 event)
+static enum cpumf_ctr_set get_counter_set(u64 event)
 {
-	int set = -1;
+	int set = CPUMF_CTR_SET_MAX;
 
 	if (event < 32)
 		set = CPUMF_CTR_SET_BASIC;
@@ -98,6 +93,8 @@ static int get_counter_set(u64 event)
 		set = CPUMF_CTR_SET_CRYPTO;
 	else if (event < 256)
 		set = CPUMF_CTR_SET_EXT;
+	else if (event >= 448 && event < 496)
+		set = CPUMF_CTR_SET_MT_DIAG;
 
 	return set;
 }
@@ -106,6 +103,7 @@ static int validate_ctr_version(const struct hw_perf_event *hwc)
 {
 	struct cpu_hw_events *cpuhw;
 	int err = 0;
+	u16 mtdiag_ctl;
 
 	cpuhw = &get_cpu_var(cpu_hw_events);
 
@@ -125,6 +123,27 @@ static int validate_ctr_version(const struct hw_perf_event *hwc)
 		    (cpuhw->info.csvn  > 2 && hwc->config > 255))
 			err = -EOPNOTSUPP;
 		break;
+	case CPUMF_CTR_SET_MT_DIAG:
+		if (cpuhw->info.csvn <= 3)
+			err = -EOPNOTSUPP;
+		/*
+		 * MT-diagnostic counters are read-only.  The counter set
+		 * is automatically enabled and activated on all CPUs with
+		 * multithreading (SMT).  Deactivation of multithreading
+		 * also disables the counter set.  State changes are ignored
+		 * by lcctl().	Because Linux controls SMT enablement through
+		 * a kernel parameter only, the counter set is either disabled
+		 * or enabled and active.
+		 *
+		 * Thus, the counters can only be used if SMT is on and the
+		 * counter set is enabled and active.
+		 */
+		mtdiag_ctl = cpumf_state_ctl[CPUMF_CTR_SET_MT_DIAG];
+		if (!((cpuhw->info.auth_ctl & mtdiag_ctl) &&
+		      (cpuhw->info.enable_ctl & mtdiag_ctl) &&
+		      (cpuhw->info.act_ctl & mtdiag_ctl)))
+			err = -EOPNOTSUPP;
+		break;
 	}
 
 	put_cpu_var(cpu_hw_events);
@@ -230,6 +249,11 @@ static void cpumf_measurement_alert(struct ext_code ext_code,
 	/* loss of counter data alert */
 	if (alert & CPU_MF_INT_CF_LCDA)
 		pr_err("CPU[%i] Counter data was lost\n", smp_processor_id());
+
+	/* loss of MT counter data alert */
+	if (alert & CPU_MF_INT_CF_MTDA)
+		pr_warn("CPU[%i] MT counter data was lost\n",
+			smp_processor_id());
 }
 
 #define PMC_INIT      0
@@ -310,6 +334,7 @@ static int __hw_perf_event_init(struct perf_event *event)
 {
 	struct perf_event_attr *attr = &event->attr;
 	struct hw_perf_event *hwc = &event->hw;
+	enum cpumf_ctr_set set;
 	int err;
 	u64 ev;
 
@@ -353,13 +378,27 @@ static int __hw_perf_event_init(struct perf_event *event)
 	if (ev > PERF_CPUM_CF_MAX_CTR)
 		return -EINVAL;
 
-	/* Use the hardware perf event structure to store the counter number
-	 * in 'config' member and the counter set to which the counter belongs
-	 * in the 'config_base'.  The counter set (config_base) is then used
-	 * to enable/disable the counters.
-	 */
-	hwc->config = ev;
-	hwc->config_base = get_counter_set(ev);
+	/* Obtain the counter set to which the specified counter belongs */
+	set = get_counter_set(ev);
+	switch (set) {
+	case CPUMF_CTR_SET_BASIC:
+	case CPUMF_CTR_SET_USER:
+	case CPUMF_CTR_SET_CRYPTO:
+	case CPUMF_CTR_SET_EXT:
+	case CPUMF_CTR_SET_MT_DIAG:
+		/*
+		 * Use the hardware perf event structure to store the
+		 * counter number in the 'config' member and the counter
+		 * set number in the 'config_base'.  The counter set number
+		 * is then later used to enable/disable the counter(s).
+		 */
+		hwc->config = ev;
+		hwc->config_base = set;
+		break;
+	case CPUMF_CTR_SET_MAX:
+		/* The counter could not be associated to a counter set */
+		return -EINVAL;
+	};
 
 	/* Initialize for using the CPU-measurement counter facility */
 	if (!atomic_inc_not_zero(&num_events)) {