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linux/arch/powerpc/kernel/sysfs.c
Paul Mackerras a6dbf93a2a powerpc: Fix bug where perf_counters breaks oprofile 
Currently there is a bug where if you use oprofile on a pSeries
machine, then use perf_counters, then use oprofile again, oprofile
will not work correctly; it will lose the PMU configuration the next
time the hypervisor does a partition context switch, and thereafter
won't count anything.

Maynard Johnson identified the sequence causing the problem:
- oprofile setup calls ppc_enable_pmcs(), which calls
  pseries_lpar_enable_pmcs, which tells the hypervisor that we want
  to use the PMU, and sets the "PMU in use" flag in the lppaca.
  This flag tells the hypervisor whether it needs to save and restore
  the PMU config.
- The perf_counter code sets and clears the "PMU in use" flag directly
  as it context-switches the PMU between tasks, and leaves it clear
  when it finishes.
- oprofile setup, called for a new oprofile run, calls ppc_enable_pmcs,
  which does nothing because it has already been called.  In particular
  it doesn't set the "PMU in use" flag.

This fixes the problem by arranging for ppc_enable_pmcs to always set
the "PMU in use" flag.  It makes the perf_counter code call
ppc_enable_pmcs also rather than calling the lower-level function
directly, and removes the setting of the "PMU in use" flag from
pseries_lpar_enable_pmcs, since that is now done in its caller.

This also removes the declaration of pasemi_enable_pmcs because it
isn't defined anywhere.

Reported-by: Maynard Johnson <mpjohn@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Cc: <stable@kernel.org)
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-09-11 11:27:58 +10:00

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#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/machdep.h>
#include <asm/smp.h>
#include <asm/pmc.h>
#include "cacheinfo.h"
#ifdef CONFIG_PPC64
#include <asm/paca.h>
#include <asm/lppaca.h>
#endif
static DEFINE_PER_CPU(struct cpu, cpu_devices);
/*
* SMT snooze delay stuff, 64-bit only for now
*/
#ifdef CONFIG_PPC64
/* Time in microseconds we delay before sleeping in the idle loop */
DEFINE_PER_CPU(unsigned long, smt_snooze_delay) = { 100 };
static ssize_t store_smt_snooze_delay(struct sys_device *dev,
struct sysdev_attribute *attr,
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,
struct sysdev_attribute *attr,
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;
const unsigned int *val;
unsigned int cpu;
if (!cpu_has_feature(CPU_FTR_SMT))
return -ENODEV;
options = of_find_node_by_path("/options");
if (!options)
return -ENODEV;
val = of_get_property(options, "ibm,smt-snooze-delay", NULL);
if (!smt_snooze_cmdline && val) {
for_each_possible_cpu(cpu)
per_cpu(smt_snooze_delay, cpu) = *val;
}
of_node_put(options);
return 0;
}
__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_possible_cpu(cpu)
per_cpu(smt_snooze_delay, cpu) = snooze;
}
return 1;
}
__setup("smt-snooze-delay=", setup_smt_snooze_delay);
#endif /* CONFIG_PPC64 */
/*
* 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 ppc_enable_pmcs(void)
{
ppc_set_pmu_inuse(1);
/* 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(ppc_enable_pmcs);
#define SYSFS_PMCSETUP(NAME, ADDRESS) \
static void read_##NAME(void *val) \
{ \
*(unsigned long *)val = mfspr(ADDRESS); \
} \
static void write_##NAME(void *val) \
{ \
ppc_enable_pmcs(); \
mtspr(ADDRESS, *(unsigned long *)val); \
} \
static ssize_t show_##NAME(struct sys_device *dev, \
struct sysdev_attribute *attr, \
char *buf) \
{ \
struct cpu *cpu = container_of(dev, struct cpu, sysdev); \
unsigned long val; \
smp_call_function_single(cpu->sysdev.id, read_##NAME, &val, 1); \
return sprintf(buf, "%lx\n", val); \
} \
static ssize_t __used \
store_##NAME(struct sys_device *dev, struct sysdev_attribute *attr, \
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; \
smp_call_function_single(cpu->sysdev.id, write_##NAME, &val, 1); \
return count; \
}
/* Let's define all possible registers, we'll only hook up the ones
* that are implemented on the current processor
*/
#if defined(CONFIG_PPC64)
#define HAS_PPC_PMC_CLASSIC 1
#define HAS_PPC_PMC_IBM 1
#define HAS_PPC_PMC_PA6T 1
#elif defined(CONFIG_6xx)
#define HAS_PPC_PMC_CLASSIC 1
#define HAS_PPC_PMC_IBM 1
#define HAS_PPC_PMC_G4 1
#endif
#ifdef HAS_PPC_PMC_CLASSIC
SYSFS_PMCSETUP(mmcr0, SPRN_MMCR0);
SYSFS_PMCSETUP(mmcr1, SPRN_MMCR1);
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);
#ifdef HAS_PPC_PMC_G4
SYSFS_PMCSETUP(mmcr2, SPRN_MMCR2);
#endif
#ifdef CONFIG_PPC64
SYSFS_PMCSETUP(pmc7, SPRN_PMC7);
SYSFS_PMCSETUP(pmc8, SPRN_PMC8);
SYSFS_PMCSETUP(mmcra, SPRN_MMCRA);
SYSFS_PMCSETUP(purr, SPRN_PURR);
SYSFS_PMCSETUP(spurr, SPRN_SPURR);
SYSFS_PMCSETUP(dscr, SPRN_DSCR);
static SYSDEV_ATTR(mmcra, 0600, show_mmcra, store_mmcra);
static SYSDEV_ATTR(spurr, 0600, show_spurr, NULL);
static SYSDEV_ATTR(dscr, 0600, show_dscr, store_dscr);
static SYSDEV_ATTR(purr, 0600, show_purr, store_purr);
#endif /* CONFIG_PPC64 */
#ifdef HAS_PPC_PMC_PA6T
SYSFS_PMCSETUP(pa6t_pmc0, SPRN_PA6T_PMC0);
SYSFS_PMCSETUP(pa6t_pmc1, SPRN_PA6T_PMC1);
SYSFS_PMCSETUP(pa6t_pmc2, SPRN_PA6T_PMC2);
SYSFS_PMCSETUP(pa6t_pmc3, SPRN_PA6T_PMC3);
SYSFS_PMCSETUP(pa6t_pmc4, SPRN_PA6T_PMC4);
SYSFS_PMCSETUP(pa6t_pmc5, SPRN_PA6T_PMC5);
#ifdef CONFIG_DEBUG_KERNEL
SYSFS_PMCSETUP(hid0, SPRN_HID0);
SYSFS_PMCSETUP(hid1, SPRN_HID1);
SYSFS_PMCSETUP(hid4, SPRN_HID4);
SYSFS_PMCSETUP(hid5, SPRN_HID5);
SYSFS_PMCSETUP(ima0, SPRN_PA6T_IMA0);
SYSFS_PMCSETUP(ima1, SPRN_PA6T_IMA1);
SYSFS_PMCSETUP(ima2, SPRN_PA6T_IMA2);
SYSFS_PMCSETUP(ima3, SPRN_PA6T_IMA3);
SYSFS_PMCSETUP(ima4, SPRN_PA6T_IMA4);
SYSFS_PMCSETUP(ima5, SPRN_PA6T_IMA5);
SYSFS_PMCSETUP(ima6, SPRN_PA6T_IMA6);
SYSFS_PMCSETUP(ima7, SPRN_PA6T_IMA7);
SYSFS_PMCSETUP(ima8, SPRN_PA6T_IMA8);
SYSFS_PMCSETUP(ima9, SPRN_PA6T_IMA9);
SYSFS_PMCSETUP(imaat, SPRN_PA6T_IMAAT);
SYSFS_PMCSETUP(btcr, SPRN_PA6T_BTCR);
SYSFS_PMCSETUP(pccr, SPRN_PA6T_PCCR);
SYSFS_PMCSETUP(rpccr, SPRN_PA6T_RPCCR);
SYSFS_PMCSETUP(der, SPRN_PA6T_DER);
SYSFS_PMCSETUP(mer, SPRN_PA6T_MER);
SYSFS_PMCSETUP(ber, SPRN_PA6T_BER);
SYSFS_PMCSETUP(ier, SPRN_PA6T_IER);
SYSFS_PMCSETUP(sier, SPRN_PA6T_SIER);
SYSFS_PMCSETUP(siar, SPRN_PA6T_SIAR);
SYSFS_PMCSETUP(tsr0, SPRN_PA6T_TSR0);
SYSFS_PMCSETUP(tsr1, SPRN_PA6T_TSR1);
SYSFS_PMCSETUP(tsr2, SPRN_PA6T_TSR2);
SYSFS_PMCSETUP(tsr3, SPRN_PA6T_TSR3);
#endif /* CONFIG_DEBUG_KERNEL */
#endif /* HAS_PPC_PMC_PA6T */
#ifdef HAS_PPC_PMC_IBM
static struct sysdev_attribute ibm_common_attrs[] = {
_SYSDEV_ATTR(mmcr0, 0600, show_mmcr0, store_mmcr0),
_SYSDEV_ATTR(mmcr1, 0600, show_mmcr1, store_mmcr1),
};
#endif /* HAS_PPC_PMC_G4 */
#ifdef HAS_PPC_PMC_G4
static struct sysdev_attribute g4_common_attrs[] = {
_SYSDEV_ATTR(mmcr0, 0600, show_mmcr0, store_mmcr0),
_SYSDEV_ATTR(mmcr1, 0600, show_mmcr1, store_mmcr1),
_SYSDEV_ATTR(mmcr2, 0600, show_mmcr2, store_mmcr2),
};
#endif /* HAS_PPC_PMC_G4 */
static struct sysdev_attribute classic_pmc_attrs[] = {
_SYSDEV_ATTR(pmc1, 0600, show_pmc1, store_pmc1),
_SYSDEV_ATTR(pmc2, 0600, show_pmc2, store_pmc2),
_SYSDEV_ATTR(pmc3, 0600, show_pmc3, store_pmc3),
_SYSDEV_ATTR(pmc4, 0600, show_pmc4, store_pmc4),
_SYSDEV_ATTR(pmc5, 0600, show_pmc5, store_pmc5),
_SYSDEV_ATTR(pmc6, 0600, show_pmc6, store_pmc6),
#ifdef CONFIG_PPC64
_SYSDEV_ATTR(pmc7, 0600, show_pmc7, store_pmc7),
_SYSDEV_ATTR(pmc8, 0600, show_pmc8, store_pmc8),
#endif
};
#ifdef HAS_PPC_PMC_PA6T
static struct sysdev_attribute pa6t_attrs[] = {
_SYSDEV_ATTR(mmcr0, 0600, show_mmcr0, store_mmcr0),
_SYSDEV_ATTR(mmcr1, 0600, show_mmcr1, store_mmcr1),
_SYSDEV_ATTR(pmc0, 0600, show_pa6t_pmc0, store_pa6t_pmc0),
_SYSDEV_ATTR(pmc1, 0600, show_pa6t_pmc1, store_pa6t_pmc1),
_SYSDEV_ATTR(pmc2, 0600, show_pa6t_pmc2, store_pa6t_pmc2),
_SYSDEV_ATTR(pmc3, 0600, show_pa6t_pmc3, store_pa6t_pmc3),
_SYSDEV_ATTR(pmc4, 0600, show_pa6t_pmc4, store_pa6t_pmc4),
_SYSDEV_ATTR(pmc5, 0600, show_pa6t_pmc5, store_pa6t_pmc5),
#ifdef CONFIG_DEBUG_KERNEL
_SYSDEV_ATTR(hid0, 0600, show_hid0, store_hid0),
_SYSDEV_ATTR(hid1, 0600, show_hid1, store_hid1),
_SYSDEV_ATTR(hid4, 0600, show_hid4, store_hid4),
_SYSDEV_ATTR(hid5, 0600, show_hid5, store_hid5),
_SYSDEV_ATTR(ima0, 0600, show_ima0, store_ima0),
_SYSDEV_ATTR(ima1, 0600, show_ima1, store_ima1),
_SYSDEV_ATTR(ima2, 0600, show_ima2, store_ima2),
_SYSDEV_ATTR(ima3, 0600, show_ima3, store_ima3),
_SYSDEV_ATTR(ima4, 0600, show_ima4, store_ima4),
_SYSDEV_ATTR(ima5, 0600, show_ima5, store_ima5),
_SYSDEV_ATTR(ima6, 0600, show_ima6, store_ima6),
_SYSDEV_ATTR(ima7, 0600, show_ima7, store_ima7),
_SYSDEV_ATTR(ima8, 0600, show_ima8, store_ima8),
_SYSDEV_ATTR(ima9, 0600, show_ima9, store_ima9),
_SYSDEV_ATTR(imaat, 0600, show_imaat, store_imaat),
_SYSDEV_ATTR(btcr, 0600, show_btcr, store_btcr),
_SYSDEV_ATTR(pccr, 0600, show_pccr, store_pccr),
_SYSDEV_ATTR(rpccr, 0600, show_rpccr, store_rpccr),
_SYSDEV_ATTR(der, 0600, show_der, store_der),
_SYSDEV_ATTR(mer, 0600, show_mer, store_mer),
_SYSDEV_ATTR(ber, 0600, show_ber, store_ber),
_SYSDEV_ATTR(ier, 0600, show_ier, store_ier),
_SYSDEV_ATTR(sier, 0600, show_sier, store_sier),
_SYSDEV_ATTR(siar, 0600, show_siar, store_siar),
_SYSDEV_ATTR(tsr0, 0600, show_tsr0, store_tsr0),
_SYSDEV_ATTR(tsr1, 0600, show_tsr1, store_tsr1),
_SYSDEV_ATTR(tsr2, 0600, show_tsr2, store_tsr2),
_SYSDEV_ATTR(tsr3, 0600, show_tsr3, store_tsr3),
#endif /* CONFIG_DEBUG_KERNEL */
};
#endif /* HAS_PPC_PMC_PA6T */
#endif /* HAS_PPC_PMC_CLASSIC */
static void __cpuinit register_cpu_online(unsigned int cpu)
{
struct cpu *c = &per_cpu(cpu_devices, cpu);
struct sys_device *s = &c->sysdev;
struct sysdev_attribute *attrs, *pmc_attrs;
int i, nattrs;
#ifdef CONFIG_PPC64
if (!firmware_has_feature(FW_FEATURE_ISERIES) &&
cpu_has_feature(CPU_FTR_SMT))
sysdev_create_file(s, &attr_smt_snooze_delay);
#endif
/* PMC stuff */
switch (cur_cpu_spec->pmc_type) {
#ifdef HAS_PPC_PMC_IBM
case PPC_PMC_IBM:
attrs = ibm_common_attrs;
nattrs = sizeof(ibm_common_attrs) / sizeof(struct sysdev_attribute);
pmc_attrs = classic_pmc_attrs;
break;
#endif /* HAS_PPC_PMC_IBM */
#ifdef HAS_PPC_PMC_G4
case PPC_PMC_G4:
attrs = g4_common_attrs;
nattrs = sizeof(g4_common_attrs) / sizeof(struct sysdev_attribute);
pmc_attrs = classic_pmc_attrs;
break;
#endif /* HAS_PPC_PMC_G4 */
#ifdef HAS_PPC_PMC_PA6T
case PPC_PMC_PA6T:
/* PA Semi starts counting at PMC0 */
attrs = pa6t_attrs;
nattrs = sizeof(pa6t_attrs) / sizeof(struct sysdev_attribute);
pmc_attrs = NULL;
break;
#endif /* HAS_PPC_PMC_PA6T */
default:
attrs = NULL;
nattrs = 0;
pmc_attrs = NULL;
}
for (i = 0; i < nattrs; i++)
sysdev_create_file(s, &attrs[i]);
if (pmc_attrs)
for (i = 0; i < cur_cpu_spec->num_pmcs; i++)
sysdev_create_file(s, &pmc_attrs[i]);
#ifdef CONFIG_PPC64
if (cpu_has_feature(CPU_FTR_MMCRA))
sysdev_create_file(s, &attr_mmcra);
if (cpu_has_feature(CPU_FTR_PURR))
sysdev_create_file(s, &attr_purr);
if (cpu_has_feature(CPU_FTR_SPURR))
sysdev_create_file(s, &attr_spurr);
if (cpu_has_feature(CPU_FTR_DSCR))
sysdev_create_file(s, &attr_dscr);
#endif /* CONFIG_PPC64 */
cacheinfo_cpu_online(cpu);
}
#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;
struct sysdev_attribute *attrs, *pmc_attrs;
int i, nattrs;
BUG_ON(!c->hotpluggable);
#ifdef CONFIG_PPC64
if (!firmware_has_feature(FW_FEATURE_ISERIES) &&
cpu_has_feature(CPU_FTR_SMT))
sysdev_remove_file(s, &attr_smt_snooze_delay);
#endif
/* PMC stuff */
switch (cur_cpu_spec->pmc_type) {
#ifdef HAS_PPC_PMC_IBM
case PPC_PMC_IBM:
attrs = ibm_common_attrs;
nattrs = sizeof(ibm_common_attrs) / sizeof(struct sysdev_attribute);
pmc_attrs = classic_pmc_attrs;
break;
#endif /* HAS_PPC_PMC_IBM */
#ifdef HAS_PPC_PMC_G4
case PPC_PMC_G4:
attrs = g4_common_attrs;
nattrs = sizeof(g4_common_attrs) / sizeof(struct sysdev_attribute);
pmc_attrs = classic_pmc_attrs;
break;
#endif /* HAS_PPC_PMC_G4 */
#ifdef HAS_PPC_PMC_PA6T
case PPC_PMC_PA6T:
/* PA Semi starts counting at PMC0 */
attrs = pa6t_attrs;
nattrs = sizeof(pa6t_attrs) / sizeof(struct sysdev_attribute);
pmc_attrs = NULL;
break;
#endif /* HAS_PPC_PMC_PA6T */
default:
attrs = NULL;
nattrs = 0;
pmc_attrs = NULL;
}
for (i = 0; i < nattrs; i++)
sysdev_remove_file(s, &attrs[i]);
if (pmc_attrs)
for (i = 0; i < cur_cpu_spec->num_pmcs; i++)
sysdev_remove_file(s, &pmc_attrs[i]);
#ifdef CONFIG_PPC64
if (cpu_has_feature(CPU_FTR_MMCRA))
sysdev_remove_file(s, &attr_mmcra);
if (cpu_has_feature(CPU_FTR_PURR))
sysdev_remove_file(s, &attr_purr);
if (cpu_has_feature(CPU_FTR_SPURR))
sysdev_remove_file(s, &attr_spurr);
if (cpu_has_feature(CPU_FTR_DSCR))
sysdev_remove_file(s, &attr_dscr);
#endif /* CONFIG_PPC64 */
cacheinfo_cpu_offline(cpu);
}
#endif /* CONFIG_HOTPLUG_CPU */
static int __cpuinit sysfs_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu)
{
unsigned int cpu = (unsigned int)(long)hcpu;
switch (action) {
case CPU_ONLINE:
case CPU_ONLINE_FROZEN:
register_cpu_online(cpu);
break;
#ifdef CONFIG_HOTPLUG_CPU
case CPU_DEAD:
case CPU_DEAD_FROZEN:
unregister_cpu_online(cpu);
break;
#endif
}
return NOTIFY_OK;
}
static struct notifier_block __cpuinitdata sysfs_cpu_nb = {
.notifier_call = sysfs_cpu_notify,
};
static DEFINE_MUTEX(cpu_mutex);
int cpu_add_sysdev_attr(struct sysdev_attribute *attr)
{
int cpu;
mutex_lock(&cpu_mutex);
for_each_possible_cpu(cpu) {
sysdev_create_file(get_cpu_sysdev(cpu), attr);
}
mutex_unlock(&cpu_mutex);
return 0;
}
EXPORT_SYMBOL_GPL(cpu_add_sysdev_attr);
int cpu_add_sysdev_attr_group(struct attribute_group *attrs)
{
int cpu;
struct sys_device *sysdev;
int ret;
mutex_lock(&cpu_mutex);
for_each_possible_cpu(cpu) {
sysdev = get_cpu_sysdev(cpu);
ret = sysfs_create_group(&sysdev->kobj, attrs);
WARN_ON(ret != 0);
}
mutex_unlock(&cpu_mutex);
return 0;
}
EXPORT_SYMBOL_GPL(cpu_add_sysdev_attr_group);
void cpu_remove_sysdev_attr(struct sysdev_attribute *attr)
{
int cpu;
mutex_lock(&cpu_mutex);
for_each_possible_cpu(cpu) {
sysdev_remove_file(get_cpu_sysdev(cpu), attr);
}
mutex_unlock(&cpu_mutex);
}
EXPORT_SYMBOL_GPL(cpu_remove_sysdev_attr);
void cpu_remove_sysdev_attr_group(struct attribute_group *attrs)
{
int cpu;
struct sys_device *sysdev;
mutex_lock(&cpu_mutex);
for_each_possible_cpu(cpu) {
sysdev = get_cpu_sysdev(cpu);
sysfs_remove_group(&sysdev->kobj, attrs);
}
mutex_unlock(&cpu_mutex);
}
EXPORT_SYMBOL_GPL(cpu_remove_sysdev_attr_group);
/* NUMA stuff */
#ifdef CONFIG_NUMA
static void register_nodes(void)
{
int i;
for (i = 0; i < MAX_NUMNODES; i++)
register_one_node(i);
}
int sysfs_add_device_to_node(struct sys_device *dev, int nid)
{
struct node *node = &node_devices[nid];
return sysfs_create_link(&node->sysdev.kobj, &dev->kobj,
kobject_name(&dev->kobj));
}
EXPORT_SYMBOL_GPL(sysfs_add_device_to_node);
void sysfs_remove_device_from_node(struct sys_device *dev, int nid)
{
struct node *node = &node_devices[nid];
sysfs_remove_link(&node->sysdev.kobj, kobject_name(&dev->kobj));
}
EXPORT_SYMBOL_GPL(sysfs_remove_device_from_node);
#else
static void register_nodes(void)
{
return;
}
#endif
/* Only valid if CPU is present. */
static ssize_t show_physical_id(struct sys_device *dev,
struct sysdev_attribute *attr, 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;
register_nodes();
register_cpu_notifier(&sysfs_cpu_nb);
for_each_possible_cpu(cpu) {
struct cpu *c = &per_cpu(cpu_devices, cpu);
/*
* 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->hotpluggable = 1;
if (cpu_online(cpu) || c->hotpluggable) {
register_cpu(c, cpu);
sysdev_create_file(&c->sysdev, &attr_physical_id);
}
if (cpu_online(cpu))
register_cpu_online(cpu);
}
return 0;
}
subsys_initcall(topology_init);
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