2 * arch/s390/kernel/smp.c
4 * Copyright IBM Corp. 1999,2007
5 * Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
6 * Martin Schwidefsky (schwidefsky@de.ibm.com)
7 * Heiko Carstens (heiko.carstens@de.ibm.com)
9 * based on other smp stuff by
10 * (c) 1995 Alan Cox, CymruNET Ltd <alan@cymru.net>
11 * (c) 1998 Ingo Molnar
13 * We work with logical cpu numbering everywhere we can. The only
14 * functions using the real cpu address (got from STAP) are the sigp
15 * functions. For all other functions we use the identity mapping.
16 * That means that cpu_number_map[i] == i for every cpu. cpu_number_map is
17 * used e.g. to find the idle task belonging to a logical cpu. Every array
18 * in the kernel is sorted by the logical cpu number and not by the physical
19 * one which is causing all the confusion with __cpu_logical_map and
20 * cpu_number_map in other architectures.
23 #include <linux/module.h>
24 #include <linux/init.h>
26 #include <linux/err.h>
27 #include <linux/spinlock.h>
28 #include <linux/kernel_stat.h>
29 #include <linux/delay.h>
30 #include <linux/cache.h>
31 #include <linux/interrupt.h>
32 #include <linux/cpu.h>
33 #include <linux/timex.h>
34 #include <linux/bootmem.h>
36 #include <asm/setup.h>
38 #include <asm/pgalloc.h>
40 #include <asm/s390_ext.h>
41 #include <asm/cpcmd.h>
42 #include <asm/tlbflush.h>
43 #include <asm/timer.h>
44 #include <asm/lowcore.h>
49 * An array with a pointer the lowcore of every CPU.
51 struct _lowcore *lowcore_ptr[NR_CPUS];
52 EXPORT_SYMBOL(lowcore_ptr);
54 cpumask_t cpu_online_map = CPU_MASK_NONE;
55 EXPORT_SYMBOL(cpu_online_map);
57 cpumask_t cpu_possible_map = CPU_MASK_ALL;
58 EXPORT_SYMBOL(cpu_possible_map);
60 static struct task_struct *current_set[NR_CPUS];
62 static u8 smp_cpu_type;
63 static int smp_use_sigp_detection;
70 #ifdef CONFIG_HOTPLUG_CPU
71 static DEFINE_MUTEX(smp_cpu_state_mutex);
73 static int smp_cpu_state[NR_CPUS];
75 static DEFINE_PER_CPU(struct cpu, cpu_devices);
76 DEFINE_PER_CPU(struct s390_idle_data, s390_idle);
78 static void smp_ext_bitcall(int, ec_bit_sig);
81 * Structure and data for __smp_call_function_map(). This is designed to
82 * minimise static memory requirements. It also looks cleaner.
84 static DEFINE_SPINLOCK(call_lock);
86 struct call_data_struct {
87 void (*func) (void *info);
94 static struct call_data_struct *call_data;
97 * 'Call function' interrupt callback
99 static void do_call_function(void)
101 void (*func) (void *info) = call_data->func;
102 void *info = call_data->info;
103 int wait = call_data->wait;
105 cpu_set(smp_processor_id(), call_data->started);
108 cpu_set(smp_processor_id(), call_data->finished);;
111 static void __smp_call_function_map(void (*func) (void *info), void *info,
112 int nonatomic, int wait, cpumask_t map)
114 struct call_data_struct data;
118 * Can deadlock when interrupts are disabled or if in wrong context.
120 WARN_ON(irqs_disabled() || in_irq());
123 * Check for local function call. We have to have the same call order
124 * as in on_each_cpu() because of machine_restart_smp().
126 if (cpu_isset(smp_processor_id(), map)) {
128 cpu_clear(smp_processor_id(), map);
131 cpus_and(map, map, cpu_online_map);
137 data.started = CPU_MASK_NONE;
140 data.finished = CPU_MASK_NONE;
142 spin_lock(&call_lock);
145 for_each_cpu_mask(cpu, map)
146 smp_ext_bitcall(cpu, ec_call_function);
148 /* Wait for response */
149 while (!cpus_equal(map, data.started))
152 while (!cpus_equal(map, data.finished))
154 spin_unlock(&call_lock);
165 * @func: the function to run; this must be fast and non-blocking
166 * @info: an arbitrary pointer to pass to the function
168 * @wait: if true, wait (atomically) until function has completed on other CPUs
170 * Run a function on all other CPUs.
172 * You must not call this function with disabled interrupts, from a
173 * hardware interrupt handler or from a bottom half.
175 int smp_call_function(void (*func) (void *info), void *info, int nonatomic,
181 map = cpu_online_map;
182 cpu_clear(smp_processor_id(), map);
183 __smp_call_function_map(func, info, nonatomic, wait, map);
187 EXPORT_SYMBOL(smp_call_function);
190 * smp_call_function_single:
191 * @cpu: the CPU where func should run
192 * @func: the function to run; this must be fast and non-blocking
193 * @info: an arbitrary pointer to pass to the function
195 * @wait: if true, wait (atomically) until function has completed on other CPUs
197 * Run a function on one processor.
199 * You must not call this function with disabled interrupts, from a
200 * hardware interrupt handler or from a bottom half.
202 int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
203 int nonatomic, int wait)
206 __smp_call_function_map(func, info, nonatomic, wait,
207 cpumask_of_cpu(cpu));
211 EXPORT_SYMBOL(smp_call_function_single);
213 void smp_send_stop(void)
217 /* Disable all interrupts/machine checks */
218 __load_psw_mask(psw_kernel_bits & ~PSW_MASK_MCHECK);
220 /* write magic number to zero page (absolute 0) */
221 lowcore_ptr[smp_processor_id()]->panic_magic = __PANIC_MAGIC;
223 /* stop all processors */
224 for_each_online_cpu(cpu) {
225 if (cpu == smp_processor_id())
228 rc = signal_processor(cpu, sigp_stop);
229 } while (rc == sigp_busy);
231 while (!smp_cpu_not_running(cpu))
237 * Reboot, halt and power_off routines for SMP.
239 void machine_restart_smp(char *__unused)
245 void machine_halt_smp(void)
248 if (MACHINE_IS_VM && strlen(vmhalt_cmd) > 0)
249 __cpcmd(vmhalt_cmd, NULL, 0, NULL);
250 signal_processor(smp_processor_id(), sigp_stop_and_store_status);
254 void machine_power_off_smp(void)
257 if (MACHINE_IS_VM && strlen(vmpoff_cmd) > 0)
258 __cpcmd(vmpoff_cmd, NULL, 0, NULL);
259 signal_processor(smp_processor_id(), sigp_stop_and_store_status);
264 * This is the main routine where commands issued by other
268 static void do_ext_call_interrupt(__u16 code)
273 * handle bit signal external calls
275 * For the ec_schedule signal we have to do nothing. All the work
276 * is done automatically when we return from the interrupt.
278 bits = xchg(&S390_lowcore.ext_call_fast, 0);
280 if (test_bit(ec_call_function, &bits))
285 * Send an external call sigp to another cpu and return without waiting
286 * for its completion.
288 static void smp_ext_bitcall(int cpu, ec_bit_sig sig)
291 * Set signaling bit in lowcore of target cpu and kick it
293 set_bit(sig, (unsigned long *) &lowcore_ptr[cpu]->ext_call_fast);
294 while (signal_processor(cpu, sigp_emergency_signal) == sigp_busy)
300 * this function sends a 'purge tlb' signal to another CPU.
302 void smp_ptlb_callback(void *info)
307 void smp_ptlb_all(void)
309 on_each_cpu(smp_ptlb_callback, NULL, 0, 1);
311 EXPORT_SYMBOL(smp_ptlb_all);
312 #endif /* ! CONFIG_64BIT */
315 * this function sends a 'reschedule' IPI to another CPU.
316 * it goes straight through and wastes no time serializing
317 * anything. Worst case is that we lose a reschedule ...
319 void smp_send_reschedule(int cpu)
321 smp_ext_bitcall(cpu, ec_schedule);
325 * parameter area for the set/clear control bit callbacks
327 struct ec_creg_mask_parms {
328 unsigned long orvals[16];
329 unsigned long andvals[16];
333 * callback for setting/clearing control bits
335 static void smp_ctl_bit_callback(void *info)
337 struct ec_creg_mask_parms *pp = info;
338 unsigned long cregs[16];
341 __ctl_store(cregs, 0, 15);
342 for (i = 0; i <= 15; i++)
343 cregs[i] = (cregs[i] & pp->andvals[i]) | pp->orvals[i];
344 __ctl_load(cregs, 0, 15);
348 * Set a bit in a control register of all cpus
350 void smp_ctl_set_bit(int cr, int bit)
352 struct ec_creg_mask_parms parms;
354 memset(&parms.orvals, 0, sizeof(parms.orvals));
355 memset(&parms.andvals, 0xff, sizeof(parms.andvals));
356 parms.orvals[cr] = 1 << bit;
357 on_each_cpu(smp_ctl_bit_callback, &parms, 0, 1);
359 EXPORT_SYMBOL(smp_ctl_set_bit);
362 * Clear a bit in a control register of all cpus
364 void smp_ctl_clear_bit(int cr, int bit)
366 struct ec_creg_mask_parms parms;
368 memset(&parms.orvals, 0, sizeof(parms.orvals));
369 memset(&parms.andvals, 0xff, sizeof(parms.andvals));
370 parms.andvals[cr] = ~(1L << bit);
371 on_each_cpu(smp_ctl_bit_callback, &parms, 0, 1);
373 EXPORT_SYMBOL(smp_ctl_clear_bit);
376 * In early ipl state a temp. logically cpu number is needed, so the sigp
377 * functions can be used to sense other cpus. Since NR_CPUS is >= 2 on
378 * CONFIG_SMP and the ipl cpu is logical cpu 0, it must be 1.
380 #define CPU_INIT_NO 1
382 #if defined(CONFIG_ZFCPDUMP) || defined(CONFIG_ZFCPDUMP_MODULE)
385 * zfcpdump_prefix_array holds prefix registers for the following scenario:
386 * 64 bit zfcpdump kernel and 31 bit kernel which is to be dumped. We have to
387 * save its prefix registers, since they get lost, when switching from 31 bit
390 unsigned int zfcpdump_prefix_array[NR_CPUS + 1] \
391 __attribute__((__section__(".data")));
393 static void __init smp_get_save_area(unsigned int cpu, unsigned int phy_cpu)
395 if (ipl_info.type != IPL_TYPE_FCP_DUMP)
397 if (cpu >= NR_CPUS) {
398 printk(KERN_WARNING "Registers for cpu %i not saved since dump "
399 "kernel was compiled with NR_CPUS=%i\n", cpu, NR_CPUS);
402 zfcpdump_save_areas[cpu] = kmalloc(sizeof(union save_area), GFP_KERNEL);
403 __cpu_logical_map[CPU_INIT_NO] = (__u16) phy_cpu;
404 while (signal_processor(CPU_INIT_NO, sigp_stop_and_store_status) ==
407 memcpy(zfcpdump_save_areas[cpu],
408 (void *)(unsigned long) store_prefix() + SAVE_AREA_BASE,
411 /* copy original prefix register */
412 zfcpdump_save_areas[cpu]->s390x.pref_reg = zfcpdump_prefix_array[cpu];
416 union save_area *zfcpdump_save_areas[NR_CPUS + 1];
417 EXPORT_SYMBOL_GPL(zfcpdump_save_areas);
421 static inline void smp_get_save_area(unsigned int cpu, unsigned int phy_cpu) { }
423 #endif /* CONFIG_ZFCPDUMP || CONFIG_ZFCPDUMP_MODULE */
425 static int cpu_stopped(int cpu)
429 /* Check for stopped state */
430 if (signal_processor_ps(&status, 0, cpu, sigp_sense) ==
431 sigp_status_stored) {
438 static int cpu_known(int cpu_id)
442 for_each_present_cpu(cpu) {
443 if (__cpu_logical_map[cpu] == cpu_id)
449 static int smp_rescan_cpus_sigp(cpumask_t avail)
451 int cpu_id, logical_cpu;
453 logical_cpu = first_cpu(avail);
454 if (logical_cpu == NR_CPUS)
456 for (cpu_id = 0; cpu_id <= 65535; cpu_id++) {
457 if (cpu_known(cpu_id))
459 __cpu_logical_map[logical_cpu] = cpu_id;
460 if (!cpu_stopped(logical_cpu))
462 cpu_set(logical_cpu, cpu_present_map);
463 smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
464 logical_cpu = next_cpu(logical_cpu, avail);
465 if (logical_cpu == NR_CPUS)
471 static int smp_rescan_cpus_sclp(cpumask_t avail)
473 struct sclp_cpu_info *info;
474 int cpu_id, logical_cpu, cpu;
477 logical_cpu = first_cpu(avail);
478 if (logical_cpu == NR_CPUS)
480 info = kmalloc(sizeof(*info), GFP_KERNEL);
483 rc = sclp_get_cpu_info(info);
486 for (cpu = 0; cpu < info->combined; cpu++) {
487 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
489 cpu_id = info->cpu[cpu].address;
490 if (cpu_known(cpu_id))
492 __cpu_logical_map[logical_cpu] = cpu_id;
493 cpu_set(logical_cpu, cpu_present_map);
494 if (cpu >= info->configured)
495 smp_cpu_state[logical_cpu] = CPU_STATE_STANDBY;
497 smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
498 logical_cpu = next_cpu(logical_cpu, avail);
499 if (logical_cpu == NR_CPUS)
507 static int smp_rescan_cpus(void)
511 cpus_xor(avail, cpu_possible_map, cpu_present_map);
512 if (smp_use_sigp_detection)
513 return smp_rescan_cpus_sigp(avail);
515 return smp_rescan_cpus_sclp(avail);
518 static void __init smp_detect_cpus(void)
520 unsigned int cpu, c_cpus, s_cpus;
521 struct sclp_cpu_info *info;
522 u16 boot_cpu_addr, cpu_addr;
526 boot_cpu_addr = S390_lowcore.cpu_data.cpu_addr;
527 info = kmalloc(sizeof(*info), GFP_KERNEL);
529 panic("smp_detect_cpus failed to allocate memory\n");
530 /* Use sigp detection algorithm if sclp doesn't work. */
531 if (sclp_get_cpu_info(info)) {
532 smp_use_sigp_detection = 1;
533 for (cpu = 0; cpu <= 65535; cpu++) {
534 if (cpu == boot_cpu_addr)
536 __cpu_logical_map[CPU_INIT_NO] = cpu;
537 if (!cpu_stopped(CPU_INIT_NO))
539 smp_get_save_area(c_cpus, cpu);
545 if (info->has_cpu_type) {
546 for (cpu = 0; cpu < info->combined; cpu++) {
547 if (info->cpu[cpu].address == boot_cpu_addr) {
548 smp_cpu_type = info->cpu[cpu].type;
554 for (cpu = 0; cpu < info->combined; cpu++) {
555 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
557 cpu_addr = info->cpu[cpu].address;
558 if (cpu_addr == boot_cpu_addr)
560 __cpu_logical_map[CPU_INIT_NO] = cpu_addr;
561 if (!cpu_stopped(CPU_INIT_NO)) {
565 smp_get_save_area(c_cpus, cpu_addr);
570 printk(KERN_INFO "CPUs: %d configured, %d standby\n", c_cpus, s_cpus);
573 unlock_cpu_hotplug();
577 * Activate a secondary processor.
579 int __cpuinit start_secondary(void *cpuvoid)
584 /* Enable TOD clock interrupts on the secondary cpu. */
586 #ifdef CONFIG_VIRT_TIMER
587 /* Enable cpu timer interrupts on the secondary cpu. */
590 /* Enable pfault pseudo page faults on this cpu. */
593 /* Mark this cpu as online */
594 cpu_set(smp_processor_id(), cpu_online_map);
595 /* Switch on interrupts */
597 /* Print info about this processor */
598 print_cpu_info(&S390_lowcore.cpu_data);
599 /* cpu_idle will call schedule for us */
604 static void __init smp_create_idle(unsigned int cpu)
606 struct task_struct *p;
609 * don't care about the psw and regs settings since we'll never
610 * reschedule the forked task.
614 panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p));
615 current_set[cpu] = p;
616 spin_lock_init(&(&per_cpu(s390_idle, cpu))->lock);
619 /* Upping and downing of CPUs */
620 int __cpu_up(unsigned int cpu)
622 struct task_struct *idle;
623 struct _lowcore *cpu_lowcore;
624 struct stack_frame *sf;
627 if (smp_cpu_state[cpu] != CPU_STATE_CONFIGURED)
630 ccode = signal_processor_p((__u32)(unsigned long)(lowcore_ptr[cpu]),
631 cpu, sigp_set_prefix);
633 printk("sigp_set_prefix failed for cpu %d "
634 "with condition code %d\n",
635 (int) cpu, (int) ccode);
639 idle = current_set[cpu];
640 cpu_lowcore = lowcore_ptr[cpu];
641 cpu_lowcore->kernel_stack = (unsigned long)
642 task_stack_page(idle) + THREAD_SIZE;
643 sf = (struct stack_frame *) (cpu_lowcore->kernel_stack
644 - sizeof(struct pt_regs)
645 - sizeof(struct stack_frame));
646 memset(sf, 0, sizeof(struct stack_frame));
647 sf->gprs[9] = (unsigned long) sf;
648 cpu_lowcore->save_area[15] = (unsigned long) sf;
649 __ctl_store(cpu_lowcore->cregs_save_area[0], 0, 15);
652 : : "a" (&cpu_lowcore->access_regs_save_area) : "memory");
653 cpu_lowcore->percpu_offset = __per_cpu_offset[cpu];
654 cpu_lowcore->current_task = (unsigned long) idle;
655 cpu_lowcore->cpu_data.cpu_nr = cpu;
658 while (signal_processor(cpu, sigp_restart) == sigp_busy)
661 while (!cpu_online(cpu))
666 static int __init setup_possible_cpus(char *s)
670 pcpus = simple_strtoul(s, NULL, 0);
671 cpu_possible_map = cpumask_of_cpu(0);
672 for (cpu = 1; cpu < pcpus && cpu < NR_CPUS; cpu++)
673 cpu_set(cpu, cpu_possible_map);
676 early_param("possible_cpus", setup_possible_cpus);
678 #ifdef CONFIG_HOTPLUG_CPU
680 int __cpu_disable(void)
682 struct ec_creg_mask_parms cr_parms;
683 int cpu = smp_processor_id();
685 cpu_clear(cpu, cpu_online_map);
687 /* Disable pfault pseudo page faults on this cpu. */
690 memset(&cr_parms.orvals, 0, sizeof(cr_parms.orvals));
691 memset(&cr_parms.andvals, 0xff, sizeof(cr_parms.andvals));
693 /* disable all external interrupts */
694 cr_parms.orvals[0] = 0;
695 cr_parms.andvals[0] = ~(1 << 15 | 1 << 14 | 1 << 13 | 1 << 12 |
696 1 << 11 | 1 << 10 | 1 << 6 | 1 << 4);
697 /* disable all I/O interrupts */
698 cr_parms.orvals[6] = 0;
699 cr_parms.andvals[6] = ~(1 << 31 | 1 << 30 | 1 << 29 | 1 << 28 |
700 1 << 27 | 1 << 26 | 1 << 25 | 1 << 24);
701 /* disable most machine checks */
702 cr_parms.orvals[14] = 0;
703 cr_parms.andvals[14] = ~(1 << 28 | 1 << 27 | 1 << 26 |
706 smp_ctl_bit_callback(&cr_parms);
711 void __cpu_die(unsigned int cpu)
713 /* Wait until target cpu is down */
714 while (!smp_cpu_not_running(cpu))
716 printk(KERN_INFO "Processor %d spun down\n", cpu);
722 signal_processor(smp_processor_id(), sigp_stop);
727 #endif /* CONFIG_HOTPLUG_CPU */
730 * Cycle through the processors and setup structures.
733 void __init smp_prepare_cpus(unsigned int max_cpus)
741 /* request the 0x1201 emergency signal external interrupt */
742 if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0)
743 panic("Couldn't request external interrupt 0x1201");
744 memset(lowcore_ptr, 0, sizeof(lowcore_ptr));
746 * Initialize prefix pages and stacks for all possible cpus
748 print_cpu_info(&S390_lowcore.cpu_data);
750 for_each_possible_cpu(i) {
751 lowcore_ptr[i] = (struct _lowcore *)
752 __get_free_pages(GFP_KERNEL | GFP_DMA,
753 sizeof(void*) == 8 ? 1 : 0);
754 stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
755 if (!lowcore_ptr[i] || !stack)
756 panic("smp_boot_cpus failed to allocate memory\n");
758 *(lowcore_ptr[i]) = S390_lowcore;
759 lowcore_ptr[i]->async_stack = stack + ASYNC_SIZE;
760 stack = __get_free_pages(GFP_KERNEL, 0);
762 panic("smp_boot_cpus failed to allocate memory\n");
763 lowcore_ptr[i]->panic_stack = stack + PAGE_SIZE;
765 if (MACHINE_HAS_IEEE) {
766 lowcore_ptr[i]->extended_save_area_addr =
767 (__u32) __get_free_pages(GFP_KERNEL, 0);
768 if (!lowcore_ptr[i]->extended_save_area_addr)
769 panic("smp_boot_cpus failed to "
770 "allocate memory\n");
775 if (MACHINE_HAS_IEEE)
776 ctl_set_bit(14, 29); /* enable extended save area */
778 set_prefix((u32)(unsigned long) lowcore_ptr[smp_processor_id()]);
780 for_each_possible_cpu(cpu)
781 if (cpu != smp_processor_id())
782 smp_create_idle(cpu);
785 void __init smp_prepare_boot_cpu(void)
787 BUG_ON(smp_processor_id() != 0);
789 current_thread_info()->cpu = 0;
790 cpu_set(0, cpu_present_map);
791 cpu_set(0, cpu_online_map);
792 S390_lowcore.percpu_offset = __per_cpu_offset[0];
793 current_set[0] = current;
794 smp_cpu_state[0] = CPU_STATE_CONFIGURED;
795 spin_lock_init(&(&__get_cpu_var(s390_idle))->lock);
798 void __init smp_cpus_done(unsigned int max_cpus)
803 * the frequency of the profiling timer can be changed
804 * by writing a multiplier value into /proc/profile.
806 * usually you want to run this on all CPUs ;)
808 int setup_profiling_timer(unsigned int multiplier)
813 #ifdef CONFIG_HOTPLUG_CPU
814 static ssize_t cpu_configure_show(struct sys_device *dev, char *buf)
818 mutex_lock(&smp_cpu_state_mutex);
819 count = sprintf(buf, "%d\n", smp_cpu_state[dev->id]);
820 mutex_unlock(&smp_cpu_state_mutex);
824 static ssize_t cpu_configure_store(struct sys_device *dev, const char *buf,
831 if (sscanf(buf, "%d %c", &val, &delim) != 1)
833 if (val != 0 && val != 1)
836 mutex_lock(&smp_cpu_state_mutex);
844 if (smp_cpu_state[cpu] == CPU_STATE_CONFIGURED) {
845 rc = sclp_cpu_deconfigure(__cpu_logical_map[cpu]);
847 smp_cpu_state[cpu] = CPU_STATE_STANDBY;
851 if (smp_cpu_state[cpu] == CPU_STATE_STANDBY) {
852 rc = sclp_cpu_configure(__cpu_logical_map[cpu]);
854 smp_cpu_state[cpu] = CPU_STATE_CONFIGURED;
861 unlock_cpu_hotplug();
862 mutex_unlock(&smp_cpu_state_mutex);
863 return rc ? rc : count;
865 static SYSDEV_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
866 #endif /* CONFIG_HOTPLUG_CPU */
868 static ssize_t show_cpu_address(struct sys_device *dev, char *buf)
870 return sprintf(buf, "%d\n", __cpu_logical_map[dev->id]);
872 static SYSDEV_ATTR(address, 0444, show_cpu_address, NULL);
875 static struct attribute *cpu_common_attrs[] = {
876 #ifdef CONFIG_HOTPLUG_CPU
877 &attr_configure.attr,
883 static struct attribute_group cpu_common_attr_group = {
884 .attrs = cpu_common_attrs,
887 static ssize_t show_capability(struct sys_device *dev, char *buf)
889 unsigned int capability;
892 rc = get_cpu_capability(&capability);
895 return sprintf(buf, "%u\n", capability);
897 static SYSDEV_ATTR(capability, 0444, show_capability, NULL);
899 static ssize_t show_idle_count(struct sys_device *dev, char *buf)
901 struct s390_idle_data *idle;
902 unsigned long long idle_count;
904 idle = &per_cpu(s390_idle, dev->id);
905 spin_lock_irq(&idle->lock);
906 idle_count = idle->idle_count;
907 spin_unlock_irq(&idle->lock);
908 return sprintf(buf, "%llu\n", idle_count);
910 static SYSDEV_ATTR(idle_count, 0444, show_idle_count, NULL);
912 static ssize_t show_idle_time(struct sys_device *dev, char *buf)
914 struct s390_idle_data *idle;
915 unsigned long long new_time;
917 idle = &per_cpu(s390_idle, dev->id);
918 spin_lock_irq(&idle->lock);
920 new_time = get_clock();
921 idle->idle_time += new_time - idle->idle_enter;
922 idle->idle_enter = new_time;
924 new_time = idle->idle_time;
925 spin_unlock_irq(&idle->lock);
926 return sprintf(buf, "%llu\n", new_time >> 12);
928 static SYSDEV_ATTR(idle_time_us, 0444, show_idle_time, NULL);
930 static struct attribute *cpu_online_attrs[] = {
931 &attr_capability.attr,
932 &attr_idle_count.attr,
933 &attr_idle_time_us.attr,
937 static struct attribute_group cpu_online_attr_group = {
938 .attrs = cpu_online_attrs,
941 static int __cpuinit smp_cpu_notify(struct notifier_block *self,
942 unsigned long action, void *hcpu)
944 unsigned int cpu = (unsigned int)(long)hcpu;
945 struct cpu *c = &per_cpu(cpu_devices, cpu);
946 struct sys_device *s = &c->sysdev;
947 struct s390_idle_data *idle;
951 case CPU_ONLINE_FROZEN:
952 idle = &per_cpu(s390_idle, cpu);
953 spin_lock_irq(&idle->lock);
954 idle->idle_enter = 0;
956 idle->idle_count = 0;
957 spin_unlock_irq(&idle->lock);
958 if (sysfs_create_group(&s->kobj, &cpu_online_attr_group))
962 case CPU_DEAD_FROZEN:
963 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
969 static struct notifier_block __cpuinitdata smp_cpu_nb = {
970 .notifier_call = smp_cpu_notify,
973 static int smp_add_present_cpu(int cpu)
975 struct cpu *c = &per_cpu(cpu_devices, cpu);
976 struct sys_device *s = &c->sysdev;
980 rc = register_cpu(c, cpu);
983 rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
986 if (!cpu_online(cpu))
988 rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
991 sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
993 #ifdef CONFIG_HOTPLUG_CPU
1000 #ifdef CONFIG_HOTPLUG_CPU
1001 static ssize_t rescan_store(struct sys_device *dev, const char *buf,
1008 mutex_lock(&smp_cpu_state_mutex);
1010 newcpus = cpu_present_map;
1011 rc = smp_rescan_cpus();
1014 cpus_andnot(newcpus, cpu_present_map, newcpus);
1015 for_each_cpu_mask(cpu, newcpus) {
1016 rc = smp_add_present_cpu(cpu);
1018 cpu_clear(cpu, cpu_present_map);
1022 unlock_cpu_hotplug();
1023 mutex_unlock(&smp_cpu_state_mutex);
1024 return rc ? rc : count;
1026 static SYSDEV_ATTR(rescan, 0200, NULL, rescan_store);
1027 #endif /* CONFIG_HOTPLUG_CPU */
1029 static int __init topology_init(void)
1034 register_cpu_notifier(&smp_cpu_nb);
1036 #ifdef CONFIG_HOTPLUG_CPU
1037 rc = sysfs_create_file(&cpu_sysdev_class.kset.kobj,
1042 for_each_present_cpu(cpu) {
1043 rc = smp_add_present_cpu(cpu);
1049 subsys_initcall(topology_init);