[S390] cpu topology support for s390.
authorHeiko Carstens <heiko.carstens@de.ibm.com>
Thu, 17 Apr 2008 05:46:12 +0000 (07:46 +0200)
committerHeiko Carstens <heiko.carstens@de.ibm.com>
Thu, 17 Apr 2008 05:47:01 +0000 (07:47 +0200)
Add s390 backend so we can give the scheduler some hints about the
cpu topology.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
arch/s390/Kconfig
arch/s390/defconfig
arch/s390/kernel/Makefile
arch/s390/kernel/setup.c
arch/s390/kernel/smp.c
arch/s390/kernel/topology.c [new file with mode: 0644]
include/asm-s390/smp.h
include/asm-s390/topology.h

index 1831833c430edc8d17015c739e9262b46bc88e77..17cbc25c0c41d7efff66cbeedd021112ad1866b0 100644 (file)
@@ -3,6 +3,10 @@
 # see Documentation/kbuild/kconfig-language.txt.
 #
 
+config SCHED_MC
+       def_bool y
+       depends on SMP
+
 config MMU
        def_bool y
 
index 62f6b5a606ddf3a8afbd63983822c0f14e45d483..dcc3ec2ef643624c89d4fe94b9916ee19a23bde3 100644 (file)
@@ -3,6 +3,7 @@
 # Linux kernel version: 2.6.25-rc4
 # Wed Mar  5 11:22:59 2008
 #
+CONFIG_SCHED_MC=y
 CONFIG_MMU=y
 CONFIG_ZONE_DMA=y
 CONFIG_LOCKDEP_SUPPORT=y
index 4d3e38392cb1486dd11db7868098ec30c22808b4..ef2b2470c25c2c4ffdb5cc41b29752eabf668b28 100644 (file)
@@ -19,7 +19,7 @@ obj-y += $(if $(CONFIG_64BIT),reipl64.o,reipl.o)
 extra-y                                += head.o init_task.o vmlinux.lds
 
 obj-$(CONFIG_MODULES)          += s390_ksyms.o module.o
-obj-$(CONFIG_SMP)              += smp.o
+obj-$(CONFIG_SMP)              += smp.o topology.o
 
 obj-$(CONFIG_AUDIT)            += audit.o
 compat-obj-$(CONFIG_AUDIT)     += compat_audit.o
index d682ff135a1c29c455581c1199da85c51efb5a04..22040d087d8a1b5ffc729e34de7c3ffab3b840fb 100644 (file)
@@ -39,6 +39,7 @@
 #include <linux/pfn.h>
 #include <linux/ctype.h>
 #include <linux/reboot.h>
+#include <linux/topology.h>
 
 #include <asm/ipl.h>
 #include <asm/uaccess.h>
@@ -830,6 +831,7 @@ setup_arch(char **cmdline_p)
 
         cpu_init();
         __cpu_logical_map[0] = S390_lowcore.cpu_data.cpu_addr;
+       s390_init_cpu_topology();
 
        /*
         * Setup capabilities (ELF_HWCAP & ELF_PLATFORM).
index 8f894d380a626316c68aeb073043f027abdcfee6..5448aa87fa2350436db5fe7bdc3764874f5c3849 100644 (file)
@@ -67,9 +67,7 @@ enum s390_cpu_state {
        CPU_STATE_CONFIGURED,
 };
 
-#ifdef CONFIG_HOTPLUG_CPU
-static DEFINE_MUTEX(smp_cpu_state_mutex);
-#endif
+DEFINE_MUTEX(smp_cpu_state_mutex);
 static int smp_cpu_state[NR_CPUS];
 
 static DEFINE_PER_CPU(struct cpu, cpu_devices);
diff --git a/arch/s390/kernel/topology.c b/arch/s390/kernel/topology.c
new file mode 100644 (file)
index 0000000..369dc1c
--- /dev/null
@@ -0,0 +1,272 @@
+/*
+ *  arch/s390/kernel/topology.c
+ *
+ *    Copyright IBM Corp. 2007
+ *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/bootmem.h>
+#include <linux/sched.h>
+#include <linux/workqueue.h>
+#include <linux/cpu.h>
+#include <linux/smp.h>
+#include <asm/delay.h>
+#include <asm/s390_ext.h>
+#include <asm/sysinfo.h>
+
+#define CPU_BITS 64
+
+struct tl_cpu {
+       unsigned char reserved[6];
+       unsigned short origin;
+       unsigned long mask[CPU_BITS / BITS_PER_LONG];
+};
+
+struct tl_container {
+       unsigned char reserved[8];
+};
+
+union tl_entry {
+       unsigned char nl;
+       struct tl_cpu cpu;
+       struct tl_container container;
+};
+
+#define NR_MAG 6
+
+struct tl_info {
+       unsigned char reserved0[2];
+       unsigned short length;
+       unsigned char mag[NR_MAG];
+       unsigned char reserved1;
+       unsigned char mnest;
+       unsigned char reserved2[4];
+       union tl_entry tle[0];
+};
+
+struct core_info {
+       struct core_info *next;
+       cpumask_t mask;
+};
+
+static void topology_work_fn(struct work_struct *work);
+static struct tl_info *tl_info;
+static struct core_info core_info;
+static int machine_has_topology;
+static int machine_has_topology_irq;
+static struct timer_list topology_timer;
+static void set_topology_timer(void);
+static DECLARE_WORK(topology_work, topology_work_fn);
+
+cpumask_t cpu_coregroup_map(unsigned int cpu)
+{
+       struct core_info *core = &core_info;
+       cpumask_t mask;
+
+       cpus_clear(mask);
+       if (!machine_has_topology)
+               return cpu_present_map;
+       mutex_lock(&smp_cpu_state_mutex);
+       while (core) {
+               if (cpu_isset(cpu, core->mask)) {
+                       mask = core->mask;
+                       break;
+               }
+               core = core->next;
+       }
+       mutex_unlock(&smp_cpu_state_mutex);
+       if (cpus_empty(mask))
+               mask = cpumask_of_cpu(cpu);
+       return mask;
+}
+
+static void add_cpus_to_core(struct tl_cpu *tl_cpu, struct core_info *core)
+{
+       unsigned int cpu;
+
+       for (cpu = find_first_bit(&tl_cpu->mask[0], CPU_BITS);
+            cpu < CPU_BITS;
+            cpu = find_next_bit(&tl_cpu->mask[0], CPU_BITS, cpu + 1))
+       {
+               unsigned int rcpu, lcpu;
+
+               rcpu = CPU_BITS - 1 - cpu + tl_cpu->origin;
+               for_each_present_cpu(lcpu) {
+                       if (__cpu_logical_map[lcpu] == rcpu)
+                               cpu_set(lcpu, core->mask);
+               }
+       }
+}
+
+static void clear_cores(void)
+{
+       struct core_info *core = &core_info;
+
+       while (core) {
+               cpus_clear(core->mask);
+               core = core->next;
+       }
+}
+
+static union tl_entry *next_tle(union tl_entry *tle)
+{
+       if (tle->nl)
+               return (union tl_entry *)((struct tl_container *)tle + 1);
+       else
+               return (union tl_entry *)((struct tl_cpu *)tle + 1);
+}
+
+static void tl_to_cores(struct tl_info *info)
+{
+       union tl_entry *tle, *end;
+       struct core_info *core = &core_info;
+
+       mutex_lock(&smp_cpu_state_mutex);
+       clear_cores();
+       tle = (union tl_entry *)&info->tle;
+       end = (union tl_entry *)((unsigned long)info + info->length);
+       while (tle < end) {
+               switch (tle->nl) {
+               case 5:
+               case 4:
+               case 3:
+               case 2:
+                       break;
+               case 1:
+                       core = core->next;
+                       break;
+               case 0:
+                       add_cpus_to_core(&tle->cpu, core);
+                       break;
+               default:
+                       clear_cores();
+                       machine_has_topology = 0;
+                       return;
+               }
+               tle = next_tle(tle);
+       }
+       mutex_unlock(&smp_cpu_state_mutex);
+}
+
+static int ptf(void)
+{
+       int rc;
+
+       asm volatile(
+               "       .insn   rre,0xb9a20000,%1,%1\n"
+               "       ipm     %0\n"
+               "       srl     %0,28\n"
+               : "=d" (rc)
+               : "d" (2UL)  : "cc");
+       return rc;
+}
+
+void arch_update_cpu_topology(void)
+{
+       struct tl_info *info = tl_info;
+       struct sys_device *sysdev;
+       int cpu;
+
+       if (!machine_has_topology)
+               return;
+       ptf();
+       stsi(info, 15, 1, 2);
+       tl_to_cores(info);
+       for_each_online_cpu(cpu) {
+               sysdev = get_cpu_sysdev(cpu);
+               kobject_uevent(&sysdev->kobj, KOBJ_CHANGE);
+       }
+}
+
+static void topology_work_fn(struct work_struct *work)
+{
+       arch_reinit_sched_domains();
+}
+
+static void topology_timer_fn(unsigned long ignored)
+{
+       if (ptf())
+               schedule_work(&topology_work);
+       set_topology_timer();
+}
+
+static void set_topology_timer(void)
+{
+       topology_timer.function = topology_timer_fn;
+       topology_timer.data = 0;
+       topology_timer.expires = jiffies + 60 * HZ;
+       add_timer(&topology_timer);
+}
+
+static void topology_interrupt(__u16 code)
+{
+       schedule_work(&topology_work);
+}
+
+static int __init init_topology_update(void)
+{
+       int rc;
+
+       if (!machine_has_topology)
+               return 0;
+       init_timer(&topology_timer);
+       if (machine_has_topology_irq) {
+               rc = register_external_interrupt(0x2005, topology_interrupt);
+               if (rc)
+                       return rc;
+               ctl_set_bit(0, 8);
+       }
+       else
+               set_topology_timer();
+       return 0;
+}
+__initcall(init_topology_update);
+
+void __init s390_init_cpu_topology(void)
+{
+       unsigned long long facility_bits;
+       struct tl_info *info;
+       struct core_info *core;
+       int nr_cores;
+       int i;
+
+       if (stfle(&facility_bits, 1) <= 0)
+               return;
+       if (!(facility_bits & (1ULL << 52)) || !(facility_bits & (1ULL << 61)))
+               return;
+       machine_has_topology = 1;
+
+       if (facility_bits & (1ULL << 51))
+               machine_has_topology_irq = 1;
+
+       tl_info = alloc_bootmem_pages(PAGE_SIZE);
+       if (!tl_info)
+               goto error;
+       info = tl_info;
+       stsi(info, 15, 1, 2);
+
+       nr_cores = info->mag[NR_MAG - 2];
+       for (i = 0; i < info->mnest - 2; i++)
+               nr_cores *= info->mag[NR_MAG - 3 - i];
+
+       printk(KERN_INFO "CPU topology:");
+       for (i = 0; i < NR_MAG; i++)
+               printk(" %d", info->mag[i]);
+       printk(" / %d\n", info->mnest);
+
+       core = &core_info;
+       for (i = 0; i < nr_cores; i++) {
+               core->next = alloc_bootmem(sizeof(struct core_info));
+               core = core->next;
+               if (!core)
+                       goto error;
+       }
+       return;
+error:
+       machine_has_topology = 0;
+       machine_has_topology_irq = 0;
+}
index c7b74326a527b15eaa059cca78bdbe1fb4b57d69..a464a66c65d32c640ec43aee34205a74dfb9dfdd 100644 (file)
@@ -90,6 +90,8 @@ extern void __cpu_die (unsigned int cpu);
 extern void cpu_die (void) __attribute__ ((noreturn));
 extern int __cpu_up (unsigned int cpu);
 
+extern struct mutex smp_cpu_state_mutex;
+
 extern int smp_call_function_mask(cpumask_t mask, void (*func)(void *),
        void *info, int wait);
 #endif
index 613aa64019dae3922a29266bc26bec5a46b58994..3b28a09a21084faa39b7029a45148fd9fdb1dbe2 100644 (file)
@@ -1,6 +1,20 @@
 #ifndef _ASM_S390_TOPOLOGY_H
 #define _ASM_S390_TOPOLOGY_H
 
+#include <linux/cpumask.h>
+
+#define mc_capable()   (1)
+
+cpumask_t cpu_coregroup_map(unsigned int cpu);
+
+#ifdef CONFIG_SMP
+void s390_init_cpu_topology(void);
+#else
+static inline void s390_init_cpu_topology(void)
+{
+};
+#endif
+
 #include <asm-generic/topology.h>
 
 #endif /* _ASM_S390_TOPOLOGY_H */