s390/topology: add detection of dedicated vs shared CPUs

The topology information returned by STSI 15.x.x contains a flag
if the CPUs of a topology-list are dedicated or shared. Make this
information available if the machine provides topology information.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h
index 58eaaccd3cf03a0b423b344894b753ad7c42a49e..4c5fde30d7417fdd74e184025e0351113e9c0dff 100644 (file)
--- a/arch/s390/include/asm/processor.h
+++ b/arch/s390/include/asm/processor.h
@@ -21,6 +21,7 @@
 #define CIF_IGNORE_IRQ         5       /* ignore interrupt (for udelay) */
 #define CIF_ENABLED_WAIT       6       /* in enabled wait state */
 #define CIF_MCCK_GUEST         7       /* machine check happening in guest */
+#define CIF_DEDICATED_CPU      8       /* this CPU is dedicated */
 
 #define _CIF_MCCK_PENDING      _BITUL(CIF_MCCK_PENDING)
 #define _CIF_ASCE_PRIMARY      _BITUL(CIF_ASCE_PRIMARY)
@@ -30,6 +31,7 @@
 #define _CIF_IGNORE_IRQ                _BITUL(CIF_IGNORE_IRQ)
 #define _CIF_ENABLED_WAIT      _BITUL(CIF_ENABLED_WAIT)
 #define _CIF_MCCK_GUEST                _BITUL(CIF_MCCK_GUEST)
+#define _CIF_DEDICATED_CPU     _BITUL(CIF_DEDICATED_CPU)
 
 #ifndef __ASSEMBLY__
 

diff --git a/arch/s390/include/asm/sysinfo.h b/arch/s390/include/asm/sysinfo.h
index 2b498e58b91424b30d1f832aaf9eb1bda2fdf60a..0f09135f0ae4c134197b7e92f151eb39752882ab 100644 (file)
--- a/arch/s390/include/asm/sysinfo.h
+++ b/arch/s390/include/asm/sysinfo.h
@@ -156,7 +156,8 @@ static inline unsigned char topology_mnest_limit(void)
 struct topology_core {
        unsigned char nl;
        unsigned char reserved0[3];
-       unsigned char :6;
+       unsigned char :5;
+       unsigned char d:1;
        unsigned char pp:2;
        unsigned char reserved1;
        unsigned short origin;

diff --git a/arch/s390/include/asm/topology.h b/arch/s390/include/asm/topology.h
index 5222da162b69502942bdad09a56890e4e83d4bc4..5108176435c1de65cb709500c272d7f2fbc63375 100644 (file)
--- a/arch/s390/include/asm/topology.h
+++ b/arch/s390/include/asm/topology.h
@@ -16,6 +16,7 @@ struct cpu_topology_s390 {
        unsigned short book_id;
        unsigned short drawer_id;
        unsigned short node_id;
+       unsigned short dedicated : 1;
        cpumask_t thread_mask;
        cpumask_t core_mask;
        cpumask_t book_mask;
@@ -34,6 +35,7 @@ extern cpumask_t cpus_with_topology;
 #define topology_book_cpumask(cpu)       (&cpu_topology[cpu].book_mask)
 #define topology_drawer_id(cpu)                  (cpu_topology[cpu].drawer_id)
 #define topology_drawer_cpumask(cpu)     (&cpu_topology[cpu].drawer_mask)
+#define topology_cpu_dedicated(cpu)      (cpu_topology[cpu].dedicated)
 
 #define mc_capable() 1
 

diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 1cee6753d47a5cba115730cb73cef4324e8d3ed1..b9fc9b00d845fdd2ce8b2f83587ba3655dd736ef 100644 (file)
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -800,6 +800,8 @@ void __init smp_detect_cpus(void)
  */
 static void smp_start_secondary(void *cpuvoid)
 {
+       int cpu = smp_processor_id();
+
        S390_lowcore.last_update_clock = get_tod_clock();
        S390_lowcore.restart_stack = (unsigned long) restart_stack;
        S390_lowcore.restart_fn = (unsigned long) do_restart;
@@ -813,8 +815,12 @@ static void smp_start_secondary(void *cpuvoid)
        init_cpu_timer();
        vtime_init();
        pfault_init();
-       notify_cpu_starting(smp_processor_id());
-       set_cpu_online(smp_processor_id(), true);
+       notify_cpu_starting(cpu);
+       if (topology_cpu_dedicated(cpu))
+               set_cpu_flag(CIF_DEDICATED_CPU);
+       else
+               clear_cpu_flag(CIF_DEDICATED_CPU);
+       set_cpu_online(cpu, true);
        inc_irq_stat(CPU_RST);
        local_irq_enable();
        cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);

diff --git a/arch/s390/kernel/topology.c b/arch/s390/kernel/topology.c
index ed0bdd220e1a643788655fbefaef328dd38c7951..d49940fb43b102b2f11e407a7c43a1fdc8a08fba 100644 (file)
--- a/arch/s390/kernel/topology.c
+++ b/arch/s390/kernel/topology.c
@@ -133,6 +133,7 @@ static void add_cpus_to_mask(struct topology_core *tl_core,
                        topo->socket_id = socket->id;
                        topo->core_id = rcore;
                        topo->thread_id = lcpu + i;
+                       topo->dedicated = tl_core->d;
                        cpumask_set_cpu(lcpu + i, &drawer->mask);
                        cpumask_set_cpu(lcpu + i, &book->mask);
                        cpumask_set_cpu(lcpu + i, &socket->mask);
@@ -273,6 +274,14 @@ void store_topology(struct sysinfo_15_1_x *info)
        stsi(info, 15, 1, topology_mnest_limit());
 }
 
+static void __arch_update_dedicated_flag(void *arg)
+{
+       if (topology_cpu_dedicated(smp_processor_id()))
+               set_cpu_flag(CIF_DEDICATED_CPU);
+       else
+               clear_cpu_flag(CIF_DEDICATED_CPU);
+}
+
 static int __arch_update_cpu_topology(void)
 {
        struct sysinfo_15_1_x *info = tl_info;
@@ -298,6 +307,7 @@ int arch_update_cpu_topology(void)
        int cpu, rc;
 
        rc = __arch_update_cpu_topology();
+       on_each_cpu(__arch_update_dedicated_flag, NULL, 0);
        for_each_online_cpu(cpu) {
                dev = get_cpu_device(cpu);
                kobject_uevent(&dev->kobj, KOBJ_CHANGE);
@@ -435,9 +445,39 @@ static struct attribute_group topology_cpu_attr_group = {
        .attrs = topology_cpu_attrs,
 };
 
+static ssize_t cpu_dedicated_show(struct device *dev,
+                                 struct device_attribute *attr, char *buf)
+{
+       int cpu = dev->id;
+       ssize_t count;
+
+       mutex_lock(&smp_cpu_state_mutex);
+       count = sprintf(buf, "%d\n", topology_cpu_dedicated(cpu));
+       mutex_unlock(&smp_cpu_state_mutex);
+       return count;
+}
+static DEVICE_ATTR(dedicated, 0444, cpu_dedicated_show, NULL);
+
+static struct attribute *topology_extra_cpu_attrs[] = {
+       &dev_attr_dedicated.attr,
+       NULL,
+};
+
+static struct attribute_group topology_extra_cpu_attr_group = {
+       .attrs = topology_extra_cpu_attrs,
+};
+
 int topology_cpu_init(struct cpu *cpu)
 {
-       return sysfs_create_group(&cpu->dev.kobj, &topology_cpu_attr_group);
+       int rc;
+
+       rc = sysfs_create_group(&cpu->dev.kobj, &topology_cpu_attr_group);
+       if (rc || !MACHINE_HAS_TOPOLOGY)
+               return rc;
+       rc = sysfs_create_group(&cpu->dev.kobj, &topology_extra_cpu_attr_group);
+       if (rc)
+               sysfs_remove_group(&cpu->dev.kobj, &topology_cpu_attr_group);
+       return rc;
 }
 
 static const struct cpumask *cpu_thread_mask(int cpu)
@@ -509,6 +549,7 @@ void __init topology_init_early(void)
        alloc_masks(info, &drawer_info, 3);
 out:
        __arch_update_cpu_topology();
+       __arch_update_dedicated_flag(NULL);
 }
 
 static inline int topology_get_mode(int enabled)