linux/arch/s390/kernel/smp.c
Heiko Carstens b3dcf3de8e [S390] smp: fix sigp sense handling
sigp sense only returns the status of a cpu if it is non zero. If the
status of the sensed cpu is all zeros condition code 0 (accpeted) is
set and no status bits are returned.
The current code however assumes that a status was returned and tests
bits in it. This means uninitalized data is accessed with random
results.
Worst case is that the code that checks if cpu is offline on cpu
hotplug assumes that the target cpu is offline while it is still
running. This leads potentially to memory corruption since resources
that are still needed by the target cpu will be freed and could be
resused while still in use.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-10-29 15:05:13 +01:00

1068 lines
25 KiB
C

/*
* arch/s390/kernel/smp.c
*
* Copyright IBM Corp. 1999, 2009
* Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
* Martin Schwidefsky (schwidefsky@de.ibm.com)
* Heiko Carstens (heiko.carstens@de.ibm.com)
*
* based on other smp stuff by
* (c) 1995 Alan Cox, CymruNET Ltd <alan@cymru.net>
* (c) 1998 Ingo Molnar
*
* We work with logical cpu numbering everywhere we can. The only
* functions using the real cpu address (got from STAP) are the sigp
* functions. For all other functions we use the identity mapping.
* That means that cpu_number_map[i] == i for every cpu. cpu_number_map is
* used e.g. to find the idle task belonging to a logical cpu. Every array
* in the kernel is sorted by the logical cpu number and not by the physical
* one which is causing all the confusion with __cpu_logical_map and
* cpu_number_map in other architectures.
*/
#define KMSG_COMPONENT "cpu"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/module.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/err.h>
#include <linux/spinlock.h>
#include <linux/kernel_stat.h>
#include <linux/delay.h>
#include <linux/cache.h>
#include <linux/interrupt.h>
#include <linux/irqflags.h>
#include <linux/cpu.h>
#include <linux/timex.h>
#include <linux/bootmem.h>
#include <asm/ipl.h>
#include <asm/setup.h>
#include <asm/sigp.h>
#include <asm/pgalloc.h>
#include <asm/irq.h>
#include <asm/s390_ext.h>
#include <asm/cpcmd.h>
#include <asm/tlbflush.h>
#include <asm/timer.h>
#include <asm/lowcore.h>
#include <asm/sclp.h>
#include <asm/cputime.h>
#include <asm/vdso.h>
#include <asm/cpu.h>
#include "entry.h"
static struct task_struct *current_set[NR_CPUS];
static u8 smp_cpu_type;
static int smp_use_sigp_detection;
enum s390_cpu_state {
CPU_STATE_STANDBY,
CPU_STATE_CONFIGURED,
};
DEFINE_MUTEX(smp_cpu_state_mutex);
int smp_cpu_polarization[NR_CPUS];
static int smp_cpu_state[NR_CPUS];
static int cpu_management;
static DEFINE_PER_CPU(struct cpu, cpu_devices);
static void smp_ext_bitcall(int, ec_bit_sig);
static int cpu_stopped(int cpu)
{
__u32 status;
switch (signal_processor_ps(&status, 0, cpu, sigp_sense)) {
case sigp_status_stored:
/* Check for stopped and check stop state */
if (status & 0x50)
return 1;
break;
default:
break;
}
return 0;
}
void smp_send_stop(void)
{
int cpu, rc;
/* Disable all interrupts/machine checks */
__load_psw_mask(psw_kernel_bits & ~PSW_MASK_MCHECK);
trace_hardirqs_off();
/* stop all processors */
for_each_online_cpu(cpu) {
if (cpu == smp_processor_id())
continue;
do {
rc = signal_processor(cpu, sigp_stop);
} while (rc == sigp_busy);
while (!cpu_stopped(cpu))
cpu_relax();
}
}
/*
* This is the main routine where commands issued by other
* cpus are handled.
*/
static void do_ext_call_interrupt(__u16 code)
{
unsigned long bits;
/*
* handle bit signal external calls
*
* For the ec_schedule signal we have to do nothing. All the work
* is done automatically when we return from the interrupt.
*/
bits = xchg(&S390_lowcore.ext_call_fast, 0);
if (test_bit(ec_call_function, &bits))
generic_smp_call_function_interrupt();
if (test_bit(ec_call_function_single, &bits))
generic_smp_call_function_single_interrupt();
}
/*
* Send an external call sigp to another cpu and return without waiting
* for its completion.
*/
static void smp_ext_bitcall(int cpu, ec_bit_sig sig)
{
/*
* Set signaling bit in lowcore of target cpu and kick it
*/
set_bit(sig, (unsigned long *) &lowcore_ptr[cpu]->ext_call_fast);
while (signal_processor(cpu, sigp_emergency_signal) == sigp_busy)
udelay(10);
}
void arch_send_call_function_ipi_mask(const struct cpumask *mask)
{
int cpu;
for_each_cpu(cpu, mask)
smp_ext_bitcall(cpu, ec_call_function);
}
void arch_send_call_function_single_ipi(int cpu)
{
smp_ext_bitcall(cpu, ec_call_function_single);
}
#ifndef CONFIG_64BIT
/*
* this function sends a 'purge tlb' signal to another CPU.
*/
static void smp_ptlb_callback(void *info)
{
__tlb_flush_local();
}
void smp_ptlb_all(void)
{
on_each_cpu(smp_ptlb_callback, NULL, 1);
}
EXPORT_SYMBOL(smp_ptlb_all);
#endif /* ! CONFIG_64BIT */
/*
* this function sends a 'reschedule' IPI to another CPU.
* it goes straight through and wastes no time serializing
* anything. Worst case is that we lose a reschedule ...
*/
void smp_send_reschedule(int cpu)
{
smp_ext_bitcall(cpu, ec_schedule);
}
/*
* parameter area for the set/clear control bit callbacks
*/
struct ec_creg_mask_parms {
unsigned long orvals[16];
unsigned long andvals[16];
};
/*
* callback for setting/clearing control bits
*/
static void smp_ctl_bit_callback(void *info)
{
struct ec_creg_mask_parms *pp = info;
unsigned long cregs[16];
int i;
__ctl_store(cregs, 0, 15);
for (i = 0; i <= 15; i++)
cregs[i] = (cregs[i] & pp->andvals[i]) | pp->orvals[i];
__ctl_load(cregs, 0, 15);
}
/*
* Set a bit in a control register of all cpus
*/
void smp_ctl_set_bit(int cr, int bit)
{
struct ec_creg_mask_parms parms;
memset(&parms.orvals, 0, sizeof(parms.orvals));
memset(&parms.andvals, 0xff, sizeof(parms.andvals));
parms.orvals[cr] = 1 << bit;
on_each_cpu(smp_ctl_bit_callback, &parms, 1);
}
EXPORT_SYMBOL(smp_ctl_set_bit);
/*
* Clear a bit in a control register of all cpus
*/
void smp_ctl_clear_bit(int cr, int bit)
{
struct ec_creg_mask_parms parms;
memset(&parms.orvals, 0, sizeof(parms.orvals));
memset(&parms.andvals, 0xff, sizeof(parms.andvals));
parms.andvals[cr] = ~(1L << bit);
on_each_cpu(smp_ctl_bit_callback, &parms, 1);
}
EXPORT_SYMBOL(smp_ctl_clear_bit);
/*
* In early ipl state a temp. logically cpu number is needed, so the sigp
* functions can be used to sense other cpus. Since NR_CPUS is >= 2 on
* CONFIG_SMP and the ipl cpu is logical cpu 0, it must be 1.
*/
#define CPU_INIT_NO 1
#ifdef CONFIG_ZFCPDUMP
/*
* zfcpdump_prefix_array holds prefix registers for the following scenario:
* 64 bit zfcpdump kernel and 31 bit kernel which is to be dumped. We have to
* save its prefix registers, since they get lost, when switching from 31 bit
* to 64 bit.
*/
unsigned int zfcpdump_prefix_array[NR_CPUS + 1] \
__attribute__((__section__(".data")));
static void __init smp_get_save_area(unsigned int cpu, unsigned int phy_cpu)
{
if (ipl_info.type != IPL_TYPE_FCP_DUMP)
return;
if (cpu >= NR_CPUS) {
pr_warning("CPU %i exceeds the maximum %i and is excluded from "
"the dump\n", cpu, NR_CPUS - 1);
return;
}
zfcpdump_save_areas[cpu] = kmalloc(sizeof(union save_area), GFP_KERNEL);
__cpu_logical_map[CPU_INIT_NO] = (__u16) phy_cpu;
while (signal_processor(CPU_INIT_NO, sigp_stop_and_store_status) ==
sigp_busy)
cpu_relax();
memcpy(zfcpdump_save_areas[cpu],
(void *)(unsigned long) store_prefix() + SAVE_AREA_BASE,
SAVE_AREA_SIZE);
#ifdef CONFIG_64BIT
/* copy original prefix register */
zfcpdump_save_areas[cpu]->s390x.pref_reg = zfcpdump_prefix_array[cpu];
#endif
}
union save_area *zfcpdump_save_areas[NR_CPUS + 1];
EXPORT_SYMBOL_GPL(zfcpdump_save_areas);
#else
static inline void smp_get_save_area(unsigned int cpu, unsigned int phy_cpu) { }
#endif /* CONFIG_ZFCPDUMP */
static int cpu_known(int cpu_id)
{
int cpu;
for_each_present_cpu(cpu) {
if (__cpu_logical_map[cpu] == cpu_id)
return 1;
}
return 0;
}
static int smp_rescan_cpus_sigp(cpumask_t avail)
{
int cpu_id, logical_cpu;
logical_cpu = cpumask_first(&avail);
if (logical_cpu >= nr_cpu_ids)
return 0;
for (cpu_id = 0; cpu_id <= MAX_CPU_ADDRESS; cpu_id++) {
if (cpu_known(cpu_id))
continue;
__cpu_logical_map[logical_cpu] = cpu_id;
smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN;
if (!cpu_stopped(logical_cpu))
continue;
cpu_set(logical_cpu, cpu_present_map);
smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
logical_cpu = cpumask_next(logical_cpu, &avail);
if (logical_cpu >= nr_cpu_ids)
break;
}
return 0;
}
static int smp_rescan_cpus_sclp(cpumask_t avail)
{
struct sclp_cpu_info *info;
int cpu_id, logical_cpu, cpu;
int rc;
logical_cpu = cpumask_first(&avail);
if (logical_cpu >= nr_cpu_ids)
return 0;
info = kmalloc(sizeof(*info), GFP_KERNEL);
if (!info)
return -ENOMEM;
rc = sclp_get_cpu_info(info);
if (rc)
goto out;
for (cpu = 0; cpu < info->combined; cpu++) {
if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
continue;
cpu_id = info->cpu[cpu].address;
if (cpu_known(cpu_id))
continue;
__cpu_logical_map[logical_cpu] = cpu_id;
smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN;
cpu_set(logical_cpu, cpu_present_map);
if (cpu >= info->configured)
smp_cpu_state[logical_cpu] = CPU_STATE_STANDBY;
else
smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
logical_cpu = cpumask_next(logical_cpu, &avail);
if (logical_cpu >= nr_cpu_ids)
break;
}
out:
kfree(info);
return rc;
}
static int __smp_rescan_cpus(void)
{
cpumask_t avail;
cpus_xor(avail, cpu_possible_map, cpu_present_map);
if (smp_use_sigp_detection)
return smp_rescan_cpus_sigp(avail);
else
return smp_rescan_cpus_sclp(avail);
}
static void __init smp_detect_cpus(void)
{
unsigned int cpu, c_cpus, s_cpus;
struct sclp_cpu_info *info;
u16 boot_cpu_addr, cpu_addr;
c_cpus = 1;
s_cpus = 0;
boot_cpu_addr = __cpu_logical_map[0];
info = kmalloc(sizeof(*info), GFP_KERNEL);
if (!info)
panic("smp_detect_cpus failed to allocate memory\n");
/* Use sigp detection algorithm if sclp doesn't work. */
if (sclp_get_cpu_info(info)) {
smp_use_sigp_detection = 1;
for (cpu = 0; cpu <= MAX_CPU_ADDRESS; cpu++) {
if (cpu == boot_cpu_addr)
continue;
__cpu_logical_map[CPU_INIT_NO] = cpu;
if (!cpu_stopped(CPU_INIT_NO))
continue;
smp_get_save_area(c_cpus, cpu);
c_cpus++;
}
goto out;
}
if (info->has_cpu_type) {
for (cpu = 0; cpu < info->combined; cpu++) {
if (info->cpu[cpu].address == boot_cpu_addr) {
smp_cpu_type = info->cpu[cpu].type;
break;
}
}
}
for (cpu = 0; cpu < info->combined; cpu++) {
if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
continue;
cpu_addr = info->cpu[cpu].address;
if (cpu_addr == boot_cpu_addr)
continue;
__cpu_logical_map[CPU_INIT_NO] = cpu_addr;
if (!cpu_stopped(CPU_INIT_NO)) {
s_cpus++;
continue;
}
smp_get_save_area(c_cpus, cpu_addr);
c_cpus++;
}
out:
kfree(info);
pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
get_online_cpus();
__smp_rescan_cpus();
put_online_cpus();
}
/*
* Activate a secondary processor.
*/
int __cpuinit start_secondary(void *cpuvoid)
{
/* Setup the cpu */
cpu_init();
preempt_disable();
/* Enable TOD clock interrupts on the secondary cpu. */
init_cpu_timer();
/* Enable cpu timer interrupts on the secondary cpu. */
init_cpu_vtimer();
/* Enable pfault pseudo page faults on this cpu. */
pfault_init();
/* call cpu notifiers */
notify_cpu_starting(smp_processor_id());
/* Mark this cpu as online */
ipi_call_lock();
cpu_set(smp_processor_id(), cpu_online_map);
ipi_call_unlock();
/* Switch on interrupts */
local_irq_enable();
/* Print info about this processor */
print_cpu_info();
/* cpu_idle will call schedule for us */
cpu_idle();
return 0;
}
static void __init smp_create_idle(unsigned int cpu)
{
struct task_struct *p;
/*
* don't care about the psw and regs settings since we'll never
* reschedule the forked task.
*/
p = fork_idle(cpu);
if (IS_ERR(p))
panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p));
current_set[cpu] = p;
}
static int __cpuinit smp_alloc_lowcore(int cpu)
{
unsigned long async_stack, panic_stack;
struct _lowcore *lowcore;
lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
if (!lowcore)
return -ENOMEM;
async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
panic_stack = __get_free_page(GFP_KERNEL);
if (!panic_stack || !async_stack)
goto out;
memcpy(lowcore, &S390_lowcore, 512);
memset((char *)lowcore + 512, 0, sizeof(*lowcore) - 512);
lowcore->async_stack = async_stack + ASYNC_SIZE;
lowcore->panic_stack = panic_stack + PAGE_SIZE;
#ifndef CONFIG_64BIT
if (MACHINE_HAS_IEEE) {
unsigned long save_area;
save_area = get_zeroed_page(GFP_KERNEL);
if (!save_area)
goto out;
lowcore->extended_save_area_addr = (u32) save_area;
}
#else
if (vdso_alloc_per_cpu(cpu, lowcore))
goto out;
#endif
lowcore_ptr[cpu] = lowcore;
return 0;
out:
free_page(panic_stack);
free_pages(async_stack, ASYNC_ORDER);
free_pages((unsigned long) lowcore, LC_ORDER);
return -ENOMEM;
}
static void smp_free_lowcore(int cpu)
{
struct _lowcore *lowcore;
lowcore = lowcore_ptr[cpu];
#ifndef CONFIG_64BIT
if (MACHINE_HAS_IEEE)
free_page((unsigned long) lowcore->extended_save_area_addr);
#else
vdso_free_per_cpu(cpu, lowcore);
#endif
free_page(lowcore->panic_stack - PAGE_SIZE);
free_pages(lowcore->async_stack - ASYNC_SIZE, ASYNC_ORDER);
free_pages((unsigned long) lowcore, LC_ORDER);
lowcore_ptr[cpu] = NULL;
}
/* Upping and downing of CPUs */
int __cpuinit __cpu_up(unsigned int cpu)
{
struct task_struct *idle;
struct _lowcore *cpu_lowcore;
struct stack_frame *sf;
sigp_ccode ccode;
u32 lowcore;
if (smp_cpu_state[cpu] != CPU_STATE_CONFIGURED)
return -EIO;
if (smp_alloc_lowcore(cpu))
return -ENOMEM;
do {
ccode = signal_processor(cpu, sigp_initial_cpu_reset);
if (ccode == sigp_busy)
udelay(10);
if (ccode == sigp_not_operational)
goto err_out;
} while (ccode == sigp_busy);
lowcore = (u32)(unsigned long)lowcore_ptr[cpu];
while (signal_processor_p(lowcore, cpu, sigp_set_prefix) == sigp_busy)
udelay(10);
idle = current_set[cpu];
cpu_lowcore = lowcore_ptr[cpu];
cpu_lowcore->kernel_stack = (unsigned long)
task_stack_page(idle) + THREAD_SIZE;
cpu_lowcore->thread_info = (unsigned long) task_thread_info(idle);
sf = (struct stack_frame *) (cpu_lowcore->kernel_stack
- sizeof(struct pt_regs)
- sizeof(struct stack_frame));
memset(sf, 0, sizeof(struct stack_frame));
sf->gprs[9] = (unsigned long) sf;
cpu_lowcore->save_area[15] = (unsigned long) sf;
__ctl_store(cpu_lowcore->cregs_save_area, 0, 15);
asm volatile(
" stam 0,15,0(%0)"
: : "a" (&cpu_lowcore->access_regs_save_area) : "memory");
cpu_lowcore->percpu_offset = __per_cpu_offset[cpu];
cpu_lowcore->current_task = (unsigned long) idle;
cpu_lowcore->cpu_nr = cpu;
cpu_lowcore->kernel_asce = S390_lowcore.kernel_asce;
cpu_lowcore->machine_flags = S390_lowcore.machine_flags;
cpu_lowcore->ftrace_func = S390_lowcore.ftrace_func;
eieio();
while (signal_processor(cpu, sigp_restart) == sigp_busy)
udelay(10);
while (!cpu_online(cpu))
cpu_relax();
return 0;
err_out:
smp_free_lowcore(cpu);
return -EIO;
}
static int __init setup_possible_cpus(char *s)
{
int pcpus, cpu;
pcpus = simple_strtoul(s, NULL, 0);
init_cpu_possible(cpumask_of(0));
for (cpu = 1; cpu < pcpus && cpu < nr_cpu_ids; cpu++)
set_cpu_possible(cpu, true);
return 0;
}
early_param("possible_cpus", setup_possible_cpus);
#ifdef CONFIG_HOTPLUG_CPU
int __cpu_disable(void)
{
struct ec_creg_mask_parms cr_parms;
int cpu = smp_processor_id();
cpu_clear(cpu, cpu_online_map);
/* Disable pfault pseudo page faults on this cpu. */
pfault_fini();
memset(&cr_parms.orvals, 0, sizeof(cr_parms.orvals));
memset(&cr_parms.andvals, 0xff, sizeof(cr_parms.andvals));
/* disable all external interrupts */
cr_parms.orvals[0] = 0;
cr_parms.andvals[0] = ~(1 << 15 | 1 << 14 | 1 << 13 | 1 << 12 |
1 << 11 | 1 << 10 | 1 << 6 | 1 << 4);
/* disable all I/O interrupts */
cr_parms.orvals[6] = 0;
cr_parms.andvals[6] = ~(1 << 31 | 1 << 30 | 1 << 29 | 1 << 28 |
1 << 27 | 1 << 26 | 1 << 25 | 1 << 24);
/* disable most machine checks */
cr_parms.orvals[14] = 0;
cr_parms.andvals[14] = ~(1 << 28 | 1 << 27 | 1 << 26 |
1 << 25 | 1 << 24);
smp_ctl_bit_callback(&cr_parms);
return 0;
}
void __cpu_die(unsigned int cpu)
{
/* Wait until target cpu is down */
while (!cpu_stopped(cpu))
cpu_relax();
while (signal_processor_p(0, cpu, sigp_set_prefix) == sigp_busy)
udelay(10);
smp_free_lowcore(cpu);
pr_info("Processor %d stopped\n", cpu);
}
void cpu_die(void)
{
idle_task_exit();
while (signal_processor(smp_processor_id(), sigp_stop) == sigp_busy)
cpu_relax();
for (;;);
}
#endif /* CONFIG_HOTPLUG_CPU */
void __init smp_prepare_cpus(unsigned int max_cpus)
{
#ifndef CONFIG_64BIT
unsigned long save_area = 0;
#endif
unsigned long async_stack, panic_stack;
struct _lowcore *lowcore;
unsigned int cpu;
smp_detect_cpus();
/* request the 0x1201 emergency signal external interrupt */
if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0)
panic("Couldn't request external interrupt 0x1201");
print_cpu_info();
/* Reallocate current lowcore, but keep its contents. */
lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
panic_stack = __get_free_page(GFP_KERNEL);
async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
BUG_ON(!lowcore || !panic_stack || !async_stack);
#ifndef CONFIG_64BIT
if (MACHINE_HAS_IEEE)
save_area = get_zeroed_page(GFP_KERNEL);
#endif
local_irq_disable();
local_mcck_disable();
lowcore_ptr[smp_processor_id()] = lowcore;
*lowcore = S390_lowcore;
lowcore->panic_stack = panic_stack + PAGE_SIZE;
lowcore->async_stack = async_stack + ASYNC_SIZE;
#ifndef CONFIG_64BIT
if (MACHINE_HAS_IEEE)
lowcore->extended_save_area_addr = (u32) save_area;
#endif
set_prefix((u32)(unsigned long) lowcore);
local_mcck_enable();
local_irq_enable();
#ifdef CONFIG_64BIT
if (vdso_alloc_per_cpu(smp_processor_id(), &S390_lowcore))
BUG();
#endif
for_each_possible_cpu(cpu)
if (cpu != smp_processor_id())
smp_create_idle(cpu);
}
void __init smp_prepare_boot_cpu(void)
{
BUG_ON(smp_processor_id() != 0);
current_thread_info()->cpu = 0;
cpu_set(0, cpu_present_map);
cpu_set(0, cpu_online_map);
S390_lowcore.percpu_offset = __per_cpu_offset[0];
current_set[0] = current;
smp_cpu_state[0] = CPU_STATE_CONFIGURED;
smp_cpu_polarization[0] = POLARIZATION_UNKNWN;
}
void __init smp_cpus_done(unsigned int max_cpus)
{
}
/*
* the frequency of the profiling timer can be changed
* by writing a multiplier value into /proc/profile.
*
* usually you want to run this on all CPUs ;)
*/
int setup_profiling_timer(unsigned int multiplier)
{
return 0;
}
#ifdef CONFIG_HOTPLUG_CPU
static ssize_t cpu_configure_show(struct sys_device *dev,
struct sysdev_attribute *attr, char *buf)
{
ssize_t count;
mutex_lock(&smp_cpu_state_mutex);
count = sprintf(buf, "%d\n", smp_cpu_state[dev->id]);
mutex_unlock(&smp_cpu_state_mutex);
return count;
}
static ssize_t cpu_configure_store(struct sys_device *dev,
struct sysdev_attribute *attr,
const char *buf, size_t count)
{
int cpu = dev->id;
int val, rc;
char delim;
if (sscanf(buf, "%d %c", &val, &delim) != 1)
return -EINVAL;
if (val != 0 && val != 1)
return -EINVAL;
get_online_cpus();
mutex_lock(&smp_cpu_state_mutex);
rc = -EBUSY;
if (cpu_online(cpu))
goto out;
rc = 0;
switch (val) {
case 0:
if (smp_cpu_state[cpu] == CPU_STATE_CONFIGURED) {
rc = sclp_cpu_deconfigure(__cpu_logical_map[cpu]);
if (!rc) {
smp_cpu_state[cpu] = CPU_STATE_STANDBY;
smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
}
}
break;
case 1:
if (smp_cpu_state[cpu] == CPU_STATE_STANDBY) {
rc = sclp_cpu_configure(__cpu_logical_map[cpu]);
if (!rc) {
smp_cpu_state[cpu] = CPU_STATE_CONFIGURED;
smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
}
}
break;
default:
break;
}
out:
mutex_unlock(&smp_cpu_state_mutex);
put_online_cpus();
return rc ? rc : count;
}
static SYSDEV_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
#endif /* CONFIG_HOTPLUG_CPU */
static ssize_t cpu_polarization_show(struct sys_device *dev,
struct sysdev_attribute *attr, char *buf)
{
int cpu = dev->id;
ssize_t count;
mutex_lock(&smp_cpu_state_mutex);
switch (smp_cpu_polarization[cpu]) {
case POLARIZATION_HRZ:
count = sprintf(buf, "horizontal\n");
break;
case POLARIZATION_VL:
count = sprintf(buf, "vertical:low\n");
break;
case POLARIZATION_VM:
count = sprintf(buf, "vertical:medium\n");
break;
case POLARIZATION_VH:
count = sprintf(buf, "vertical:high\n");
break;
default:
count = sprintf(buf, "unknown\n");
break;
}
mutex_unlock(&smp_cpu_state_mutex);
return count;
}
static SYSDEV_ATTR(polarization, 0444, cpu_polarization_show, NULL);
static ssize_t show_cpu_address(struct sys_device *dev,
struct sysdev_attribute *attr, char *buf)
{
return sprintf(buf, "%d\n", __cpu_logical_map[dev->id]);
}
static SYSDEV_ATTR(address, 0444, show_cpu_address, NULL);
static struct attribute *cpu_common_attrs[] = {
#ifdef CONFIG_HOTPLUG_CPU
&attr_configure.attr,
#endif
&attr_address.attr,
&attr_polarization.attr,
NULL,
};
static struct attribute_group cpu_common_attr_group = {
.attrs = cpu_common_attrs,
};
static ssize_t show_capability(struct sys_device *dev,
struct sysdev_attribute *attr, char *buf)
{
unsigned int capability;
int rc;
rc = get_cpu_capability(&capability);
if (rc)
return rc;
return sprintf(buf, "%u\n", capability);
}
static SYSDEV_ATTR(capability, 0444, show_capability, NULL);
static ssize_t show_idle_count(struct sys_device *dev,
struct sysdev_attribute *attr, char *buf)
{
struct s390_idle_data *idle;
unsigned long long idle_count;
unsigned int sequence;
idle = &per_cpu(s390_idle, dev->id);
repeat:
sequence = idle->sequence;
smp_rmb();
if (sequence & 1)
goto repeat;
idle_count = idle->idle_count;
if (idle->idle_enter)
idle_count++;
smp_rmb();
if (idle->sequence != sequence)
goto repeat;
return sprintf(buf, "%llu\n", idle_count);
}
static SYSDEV_ATTR(idle_count, 0444, show_idle_count, NULL);
static ssize_t show_idle_time(struct sys_device *dev,
struct sysdev_attribute *attr, char *buf)
{
struct s390_idle_data *idle;
unsigned long long now, idle_time, idle_enter;
unsigned int sequence;
idle = &per_cpu(s390_idle, dev->id);
now = get_clock();
repeat:
sequence = idle->sequence;
smp_rmb();
if (sequence & 1)
goto repeat;
idle_time = idle->idle_time;
idle_enter = idle->idle_enter;
if (idle_enter != 0ULL && idle_enter < now)
idle_time += now - idle_enter;
smp_rmb();
if (idle->sequence != sequence)
goto repeat;
return sprintf(buf, "%llu\n", idle_time >> 12);
}
static SYSDEV_ATTR(idle_time_us, 0444, show_idle_time, NULL);
static struct attribute *cpu_online_attrs[] = {
&attr_capability.attr,
&attr_idle_count.attr,
&attr_idle_time_us.attr,
NULL,
};
static struct attribute_group cpu_online_attr_group = {
.attrs = cpu_online_attrs,
};
static int __cpuinit smp_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu)
{
unsigned int cpu = (unsigned int)(long)hcpu;
struct cpu *c = &per_cpu(cpu_devices, cpu);
struct sys_device *s = &c->sysdev;
struct s390_idle_data *idle;
switch (action) {
case CPU_ONLINE:
case CPU_ONLINE_FROZEN:
idle = &per_cpu(s390_idle, cpu);
memset(idle, 0, sizeof(struct s390_idle_data));
if (sysfs_create_group(&s->kobj, &cpu_online_attr_group))
return NOTIFY_BAD;
break;
case CPU_DEAD:
case CPU_DEAD_FROZEN:
sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
break;
}
return NOTIFY_OK;
}
static struct notifier_block __cpuinitdata smp_cpu_nb = {
.notifier_call = smp_cpu_notify,
};
static int __devinit smp_add_present_cpu(int cpu)
{
struct cpu *c = &per_cpu(cpu_devices, cpu);
struct sys_device *s = &c->sysdev;
int rc;
c->hotpluggable = 1;
rc = register_cpu(c, cpu);
if (rc)
goto out;
rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
if (rc)
goto out_cpu;
if (!cpu_online(cpu))
goto out;
rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
if (!rc)
return 0;
sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
out_cpu:
#ifdef CONFIG_HOTPLUG_CPU
unregister_cpu(c);
#endif
out:
return rc;
}
#ifdef CONFIG_HOTPLUG_CPU
int __ref smp_rescan_cpus(void)
{
cpumask_t newcpus;
int cpu;
int rc;
get_online_cpus();
mutex_lock(&smp_cpu_state_mutex);
newcpus = cpu_present_map;
rc = __smp_rescan_cpus();
if (rc)
goto out;
cpus_andnot(newcpus, cpu_present_map, newcpus);
for_each_cpu_mask(cpu, newcpus) {
rc = smp_add_present_cpu(cpu);
if (rc)
cpu_clear(cpu, cpu_present_map);
}
rc = 0;
out:
mutex_unlock(&smp_cpu_state_mutex);
put_online_cpus();
if (!cpus_empty(newcpus))
topology_schedule_update();
return rc;
}
static ssize_t __ref rescan_store(struct sysdev_class *class, const char *buf,
size_t count)
{
int rc;
rc = smp_rescan_cpus();
return rc ? rc : count;
}
static SYSDEV_CLASS_ATTR(rescan, 0200, NULL, rescan_store);
#endif /* CONFIG_HOTPLUG_CPU */
static ssize_t dispatching_show(struct sysdev_class *class, char *buf)
{
ssize_t count;
mutex_lock(&smp_cpu_state_mutex);
count = sprintf(buf, "%d\n", cpu_management);
mutex_unlock(&smp_cpu_state_mutex);
return count;
}
static ssize_t dispatching_store(struct sysdev_class *dev, const char *buf,
size_t count)
{
int val, rc;
char delim;
if (sscanf(buf, "%d %c", &val, &delim) != 1)
return -EINVAL;
if (val != 0 && val != 1)
return -EINVAL;
rc = 0;
get_online_cpus();
mutex_lock(&smp_cpu_state_mutex);
if (cpu_management == val)
goto out;
rc = topology_set_cpu_management(val);
if (!rc)
cpu_management = val;
out:
mutex_unlock(&smp_cpu_state_mutex);
put_online_cpus();
return rc ? rc : count;
}
static SYSDEV_CLASS_ATTR(dispatching, 0644, dispatching_show,
dispatching_store);
static int __init topology_init(void)
{
int cpu;
int rc;
register_cpu_notifier(&smp_cpu_nb);
#ifdef CONFIG_HOTPLUG_CPU
rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_rescan);
if (rc)
return rc;
#endif
rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_dispatching);
if (rc)
return rc;
for_each_present_cpu(cpu) {
rc = smp_add_present_cpu(cpu);
if (rc)
return rc;
}
return 0;
}
subsys_initcall(topology_init);