text: #include <linux/config.h>
  #include <linux/sysdev.h>
  #include <linux/cpu.h>
  #include <linux/smp.h>
  #include <linux/percpu.h>
  #include <linux/init.h>
  #include <linux/sched.h>
  #include <linux/module.h>
  #include <linux/nodemask.h>
  #include <linux/cpumask.h>
  #include <linux/notifier.h>
  
  #include <asm/current.h>
  #include <asm/processor.h>
  #include <asm/cputable.h>
  #include <asm/firmware.h>
  #include <asm/hvcall.h>
  #include <asm/prom.h>
  #include <asm/paca.h>
  #include <asm/lppaca.h>
  #include <asm/machdep.h>
  #include <asm/smp.h>
  
  static DEFINE_PER_CPU(struct cpu, cpu_devices);
  
  /* SMT stuff */
  
  #ifdef CONFIG_PPC_MULTIPLATFORM
  /* default to snooze disabled */
  DEFINE_PER_CPU(unsigned long, smt_snooze_delay);
  
  static ssize_t store_smt_snooze_delay(struct sys_device *dev, const char *buf,
  				      size_t count)
  {
  	struct cpu *cpu = container_of(dev, struct cpu, sysdev);
  	ssize_t ret;
  	unsigned long snooze;
  
  	ret = sscanf(buf, "%lu", &snooze);
  	if (ret != 1)
  		return -EINVAL;
  
  	per_cpu(smt_snooze_delay, cpu->sysdev.id) = snooze;
  
  	return count;
  }
  
  static ssize_t show_smt_snooze_delay(struct sys_device *dev, char *buf)
  {
  	struct cpu *cpu = container_of(dev, struct cpu, sysdev);
  
  	return sprintf(buf, "%lu\n", per_cpu(smt_snooze_delay, cpu->sysdev.id));
  }
  
  static SYSDEV_ATTR(smt_snooze_delay, 0644, show_smt_snooze_delay,
  		   store_smt_snooze_delay);
  
  /* Only parse OF options if the matching cmdline option was not specified */
  static int smt_snooze_cmdline;
  
  static int __init smt_setup(void)
  {
  	struct device_node *options;
  	unsigned int *val;
  	unsigned int cpu;
  
  	if (!cpu_has_feature(CPU_FTR_SMT))
  		return 1;
  
  	options = find_path_device("/options");
  	if (!options)
  		return 1;
  
  	val = (unsigned int *)get_property(options, "ibm,smt-snooze-delay",
  					   NULL);
  	if (!smt_snooze_cmdline && val) {
  		for_each_cpu(cpu)
  			per_cpu(smt_snooze_delay, cpu) = *val;
  	}
  
  	return 1;
  }
  __initcall(smt_setup);
  
  static int __init setup_smt_snooze_delay(char *str)
  {
  	unsigned int cpu;
  	int snooze;
  
  	if (!cpu_has_feature(CPU_FTR_SMT))
  		return 1;
  
  	smt_snooze_cmdline = 1;
  
  	if (get_option(&str, &snooze)) {
  		for_each_cpu(cpu)
  			per_cpu(smt_snooze_delay, cpu) = snooze;
  	}
  
  	return 1;
  }
  __setup("smt-snooze-delay=", setup_smt_snooze_delay);
  
  #endif /* CONFIG_PPC_MULTIPLATFORM */
  
  /*
   * Enabling PMCs will slow partition context switch times so we only do
   * it the first time we write to the PMCs.
   */
  
  static DEFINE_PER_CPU(char, pmcs_enabled);
  
  void ppc64_enable_pmcs(void)
  {
  	/* Only need to enable them once */
  	if (__get_cpu_var(pmcs_enabled))
  		return;
  
  	__get_cpu_var(pmcs_enabled) = 1;
  
  	if (ppc_md.enable_pmcs)
  		ppc_md.enable_pmcs();
  }
  EXPORT_SYMBOL(ppc64_enable_pmcs);
  
  /* XXX convert to rusty's on_one_cpu */
  static unsigned long run_on_cpu(unsigned long cpu,
  			        unsigned long (*func)(unsigned long),
  				unsigned long arg)
  {
  	cpumask_t old_affinity = current->cpus_allowed;
  	unsigned long ret;
  
  	/* should return -EINVAL to userspace */
  	if (set_cpus_allowed(current, cpumask_of_cpu(cpu)))
  		return 0;
  
  	ret = func(arg);
  
  	set_cpus_allowed(current, old_affinity);
  
  	return ret;
  }
  
  #define SYSFS_PMCSETUP(NAME, ADDRESS) \
  static unsigned long read_##NAME(unsigned long junk) \
  { \
  	return mfspr(ADDRESS); \
  } \
  static unsigned long write_##NAME(unsigned long val) \
  { \
  	ppc64_enable_pmcs(); \
  	mtspr(ADDRESS, val); \
  	return 0; \
  } \
  static ssize_t show_##NAME(struct sys_device *dev, char *buf) \
  { \
  	struct cpu *cpu = container_of(dev, struct cpu, sysdev); \
  	unsigned long val = run_on_cpu(cpu->sysdev.id, read_##NAME, 0); \
  	return sprintf(buf, "%lx\n", val); \
  } \
  static ssize_t __attribute_used__ \
  	store_##NAME(struct sys_device *dev, const char *buf, size_t count) \
  { \
  	struct cpu *cpu = container_of(dev, struct cpu, sysdev); \
  	unsigned long val; \
  	int ret = sscanf(buf, "%lx", &val); \
  	if (ret != 1) \
  		return -EINVAL; \
  	run_on_cpu(cpu->sysdev.id, write_##NAME, val); \
  	return count; \
  }
  
  SYSFS_PMCSETUP(mmcr0, SPRN_MMCR0);
  SYSFS_PMCSETUP(mmcr1, SPRN_MMCR1);
  SYSFS_PMCSETUP(mmcra, SPRN_MMCRA);
  SYSFS_PMCSETUP(pmc1, SPRN_PMC1);
  SYSFS_PMCSETUP(pmc2, SPRN_PMC2);
  SYSFS_PMCSETUP(pmc3, SPRN_PMC3);
  SYSFS_PMCSETUP(pmc4, SPRN_PMC4);
  SYSFS_PMCSETUP(pmc5, SPRN_PMC5);
  SYSFS_PMCSETUP(pmc6, SPRN_PMC6);
  SYSFS_PMCSETUP(pmc7, SPRN_PMC7);
  SYSFS_PMCSETUP(pmc8, SPRN_PMC8);
  SYSFS_PMCSETUP(purr, SPRN_PURR);
  
  static SYSDEV_ATTR(mmcr0, 0600, show_mmcr0, store_mmcr0);
  static SYSDEV_ATTR(mmcr1, 0600, show_mmcr1, store_mmcr1);
  static SYSDEV_ATTR(mmcra, 0600, show_mmcra, store_mmcra);
  static SYSDEV_ATTR(pmc1, 0600, show_pmc1, store_pmc1);
  static SYSDEV_ATTR(pmc2, 0600, show_pmc2, store_pmc2);
  static SYSDEV_ATTR(pmc3, 0600, show_pmc3, store_pmc3);
  static SYSDEV_ATTR(pmc4, 0600, show_pmc4, store_pmc4);
  static SYSDEV_ATTR(pmc5, 0600, show_pmc5, store_pmc5);
  static SYSDEV_ATTR(pmc6, 0600, show_pmc6, store_pmc6);
  static SYSDEV_ATTR(pmc7, 0600, show_pmc7, store_pmc7);
  static SYSDEV_ATTR(pmc8, 0600, show_pmc8, store_pmc8);
  static SYSDEV_ATTR(purr, 0600, show_purr, NULL);
  
  static void register_cpu_online(unsigned int cpu)
  {
  	struct cpu *c = &per_cpu(cpu_devices, cpu);
  	struct sys_device *s = &c->sysdev;
  
  #ifndef CONFIG_PPC_ISERIES
  	if (cpu_has_feature(CPU_FTR_SMT))
  		sysdev_create_file(s, &attr_smt_snooze_delay);
  #endif
  
  	/* PMC stuff */
  
  	sysdev_create_file(s, &attr_mmcr0);
  	sysdev_create_file(s, &attr_mmcr1);
  
  	if (cpu_has_feature(CPU_FTR_MMCRA))
  		sysdev_create_file(s, &attr_mmcra);
  
  	if (cur_cpu_spec->num_pmcs >= 1)
  		sysdev_create_file(s, &attr_pmc1);
  	if (cur_cpu_spec->num_pmcs >= 2)
  		sysdev_create_file(s, &attr_pmc2);
  	if (cur_cpu_spec->num_pmcs >= 3)
  		sysdev_create_file(s, &attr_pmc3);
  	if (cur_cpu_spec->num_pmcs >= 4)
  		sysdev_create_file(s, &attr_pmc4);
  	if (cur_cpu_spec->num_pmcs >= 5)
  		sysdev_create_file(s, &attr_pmc5);
  	if (cur_cpu_spec->num_pmcs >= 6)
  		sysdev_create_file(s, &attr_pmc6);
  	if (cur_cpu_spec->num_pmcs >= 7)
  		sysdev_create_file(s, &attr_pmc7);
  	if (cur_cpu_spec->num_pmcs >= 8)
  		sysdev_create_file(s, &attr_pmc8);
  
  	if (cpu_has_feature(CPU_FTR_SMT))
  		sysdev_create_file(s, &attr_purr);
  }
  
  #ifdef CONFIG_HOTPLUG_CPU
  static void unregister_cpu_online(unsigned int cpu)
  {
  	struct cpu *c = &per_cpu(cpu_devices, cpu);
  	struct sys_device *s = &c->sysdev;
  
  	BUG_ON(c->no_control);
  
  #ifndef CONFIG_PPC_ISERIES
  	if (cpu_has_feature(CPU_FTR_SMT))
  		sysdev_remove_file(s, &attr_smt_snooze_delay);
  #endif
  
  	/* PMC stuff */
  
  	sysdev_remove_file(s, &attr_mmcr0);
  	sysdev_remove_file(s, &attr_mmcr1);
  
  	if (cpu_has_feature(CPU_FTR_MMCRA))
  		sysdev_remove_file(s, &attr_mmcra);
  
  	if (cur_cpu_spec->num_pmcs >= 1)
  		sysdev_remove_file(s, &attr_pmc1);
  	if (cur_cpu_spec->num_pmcs >= 2)
  		sysdev_remove_file(s, &attr_pmc2);
  	if (cur_cpu_spec->num_pmcs >= 3)
  		sysdev_remove_file(s, &attr_pmc3);
  	if (cur_cpu_spec->num_pmcs >= 4)
  		sysdev_remove_file(s, &attr_pmc4);
  	if (cur_cpu_spec->num_pmcs >= 5)
  		sysdev_remove_file(s, &attr_pmc5);
  	if (cur_cpu_spec->num_pmcs >= 6)
  		sysdev_remove_file(s, &attr_pmc6);
  	if (cur_cpu_spec->num_pmcs >= 7)
  		sysdev_remove_file(s, &attr_pmc7);
  	if (cur_cpu_spec->num_pmcs >= 8)
  		sysdev_remove_file(s, &attr_pmc8);
  
  	if (cpu_has_feature(CPU_FTR_SMT))
  		sysdev_remove_file(s, &attr_purr);
  }
  #endif /* CONFIG_HOTPLUG_CPU */
  
  static int __devinit sysfs_cpu_notify(struct notifier_block *self,
  				      unsigned long action, void *hcpu)
  {
  	unsigned int cpu = (unsigned int)(long)hcpu;
  
  	switch (action) {
  	case CPU_ONLINE:
  		register_cpu_online(cpu);
  		break;
  #ifdef CONFIG_HOTPLUG_CPU
  	case CPU_DEAD:
  		unregister_cpu_online(cpu);
  		break;
  #endif
  	}
  	return NOTIFY_OK;
  }
  
  static struct notifier_block __devinitdata sysfs_cpu_nb = {
  	.notifier_call	= sysfs_cpu_notify,
  };
  
  /* NUMA stuff */
  
  #ifdef CONFIG_NUMA
  static struct node node_devices[MAX_NUMNODES];
  
  static void register_nodes(void)
  {
  	int i;
  
  	for (i = 0; i < MAX_NUMNODES; i++) {
  		if (node_online(i)) {
  			int p_node = parent_node(i);
  			struct node *parent = NULL;
  
  			if (p_node != i)
  				parent = &node_devices[p_node];
  
  			register_node(&node_devices[i], i, parent);
  		}
  	}
  }
  #else
  static void register_nodes(void)
  {
  	return;
  }
  #endif
  
  /* Only valid if CPU is present. */
  static ssize_t show_physical_id(struct sys_device *dev, char *buf)
  {
  	struct cpu *cpu = container_of(dev, struct cpu, sysdev);
  
  	return sprintf(buf, "%d\n", get_hard_smp_processor_id(cpu->sysdev.id));
  }
  static SYSDEV_ATTR(physical_id, 0444, show_physical_id, NULL);
  
  static int __init topology_init(void)
  {
  	int cpu;
  	struct node *parent = NULL;
  
  	register_nodes();
  
  	register_cpu_notifier(&sysfs_cpu_nb);
  
  	for_each_cpu(cpu) {
  		struct cpu *c = &per_cpu(cpu_devices, cpu);
  
  #ifdef CONFIG_NUMA
  		/* The node to which a cpu belongs can't be known
  		 * until the cpu is made present.
  		 */
  		parent = NULL;
  		if (cpu_present(cpu))
  			parent = &node_devices[cpu_to_node(cpu)];
  #endif
  		/*
  		 * For now, we just see if the system supports making
  		 * the RTAS calls for CPU hotplug.  But, there may be a
  		 * more comprehensive way to do this for an individual
  		 * CPU.  For instance, the boot cpu might never be valid
  		 * for hotplugging.
  		 */
  		if (!ppc_md.cpu_die)
  			c->no_control = 1;
  
  		if (cpu_online(cpu) || (c->no_control == 0)) {
  			register_cpu(c, cpu, parent);
  
  			sysdev_create_file(&c->sysdev, &attr_physical_id);
  		}
  
  		if (cpu_online(cpu))
  			register_cpu_online(cpu);
  	}
  
  	return 0;
  }
  __initcall(topology_init);
  