2 * SMP related functions
4 * Copyright IBM Corp. 1999, 2012
5 * Author(s): Denis Joseph Barrow,
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 * The code outside of smp.c uses logical cpu numbers, only smp.c does
14 * the translation of logical to physical cpu ids. All new code that
15 * operates on physical cpu numbers needs to go into smp.c.
18 #define KMSG_COMPONENT "cpu"
19 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
21 #include <linux/workqueue.h>
22 #include <linux/module.h>
23 #include <linux/init.h>
25 #include <linux/err.h>
26 #include <linux/spinlock.h>
27 #include <linux/kernel_stat.h>
28 #include <linux/delay.h>
29 #include <linux/interrupt.h>
30 #include <linux/irqflags.h>
31 #include <linux/cpu.h>
32 #include <linux/slab.h>
33 #include <linux/crash_dump.h>
34 #include <asm/asm-offsets.h>
35 #include <asm/switch_to.h>
36 #include <asm/facility.h>
38 #include <asm/setup.h>
40 #include <asm/tlbflush.h>
41 #include <asm/vtimer.h>
42 #include <asm/lowcore.h>
45 #include <asm/debug.h>
46 #include <asm/os_info.h>
53 ec_call_function_single,
64 struct _lowcore *lowcore; /* lowcore page(s) for the cpu */
65 unsigned long async_stack; /* async stack for the cpu */
66 unsigned long panic_stack; /* panic stack for the cpu */
67 unsigned long ec_mask; /* bit mask for ec_xxx functions */
68 int state; /* physical cpu state */
69 int polarization; /* physical polarization */
70 u16 address; /* physical cpu address */
73 static u8 boot_cpu_type;
74 static u16 boot_cpu_address;
75 static struct pcpu pcpu_devices[NR_CPUS];
78 * The smp_cpu_state_mutex must be held when changing the state or polarization
79 * member of a pcpu data structure within the pcpu_devices arreay.
81 DEFINE_MUTEX(smp_cpu_state_mutex);
84 * Signal processor helper functions.
86 static inline int __pcpu_sigp(u16 addr, u8 order, u32 parm, u32 *status)
88 register unsigned int reg1 asm ("1") = parm;
95 : "=d" (cc), "+d" (reg1) : "d" (addr), "a" (order) : "cc");
96 if (status && cc == 1)
101 static inline int __pcpu_sigp_relax(u16 addr, u8 order, u32 parm, u32 *status)
106 cc = __pcpu_sigp(addr, order, parm, NULL);
107 if (cc != SIGP_CC_BUSY)
113 static int pcpu_sigp_retry(struct pcpu *pcpu, u8 order, u32 parm)
117 for (retry = 0; ; retry++) {
118 cc = __pcpu_sigp(pcpu->address, order, parm, NULL);
119 if (cc != SIGP_CC_BUSY)
127 static inline int pcpu_stopped(struct pcpu *pcpu)
129 u32 uninitialized_var(status);
131 if (__pcpu_sigp(pcpu->address, SIGP_SENSE,
132 0, &status) != SIGP_CC_STATUS_STORED)
134 return !!(status & (SIGP_STATUS_CHECK_STOP|SIGP_STATUS_STOPPED));
137 static inline int pcpu_running(struct pcpu *pcpu)
139 if (__pcpu_sigp(pcpu->address, SIGP_SENSE_RUNNING,
140 0, NULL) != SIGP_CC_STATUS_STORED)
142 /* Status stored condition code is equivalent to cpu not running. */
147 * Find struct pcpu by cpu address.
149 static struct pcpu *pcpu_find_address(const struct cpumask *mask, int address)
153 for_each_cpu(cpu, mask)
154 if (pcpu_devices[cpu].address == address)
155 return pcpu_devices + cpu;
159 static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit)
163 set_bit(ec_bit, &pcpu->ec_mask);
164 order = pcpu_running(pcpu) ?
165 SIGP_EXTERNAL_CALL : SIGP_EMERGENCY_SIGNAL;
166 pcpu_sigp_retry(pcpu, order, 0);
169 static int __cpuinit pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
173 if (pcpu != &pcpu_devices[0]) {
174 pcpu->lowcore = (struct _lowcore *)
175 __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
176 pcpu->async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
177 pcpu->panic_stack = __get_free_page(GFP_KERNEL);
178 if (!pcpu->lowcore || !pcpu->panic_stack || !pcpu->async_stack)
182 memcpy(lc, &S390_lowcore, 512);
183 memset((char *) lc + 512, 0, sizeof(*lc) - 512);
184 lc->async_stack = pcpu->async_stack + ASYNC_SIZE
185 - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
186 lc->panic_stack = pcpu->panic_stack + PAGE_SIZE
187 - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
190 if (MACHINE_HAS_IEEE) {
191 lc->extended_save_area_addr = get_zeroed_page(GFP_KERNEL);
192 if (!lc->extended_save_area_addr)
196 if (vdso_alloc_per_cpu(lc))
199 lowcore_ptr[cpu] = lc;
200 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, (u32)(unsigned long) lc);
203 if (pcpu != &pcpu_devices[0]) {
204 free_page(pcpu->panic_stack);
205 free_pages(pcpu->async_stack, ASYNC_ORDER);
206 free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
211 #ifdef CONFIG_HOTPLUG_CPU
213 static void pcpu_free_lowcore(struct pcpu *pcpu)
215 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0);
216 lowcore_ptr[pcpu - pcpu_devices] = NULL;
218 if (MACHINE_HAS_IEEE) {
219 struct _lowcore *lc = pcpu->lowcore;
221 free_page((unsigned long) lc->extended_save_area_addr);
222 lc->extended_save_area_addr = 0;
225 vdso_free_per_cpu(pcpu->lowcore);
227 if (pcpu != &pcpu_devices[0]) {
228 free_page(pcpu->panic_stack);
229 free_pages(pcpu->async_stack, ASYNC_ORDER);
230 free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
234 #endif /* CONFIG_HOTPLUG_CPU */
236 static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu)
238 struct _lowcore *lc = pcpu->lowcore;
240 atomic_inc(&init_mm.context.attach_count);
242 lc->percpu_offset = __per_cpu_offset[cpu];
243 lc->kernel_asce = S390_lowcore.kernel_asce;
244 lc->machine_flags = S390_lowcore.machine_flags;
245 lc->ftrace_func = S390_lowcore.ftrace_func;
246 lc->user_timer = lc->system_timer = lc->steal_timer = 0;
247 __ctl_store(lc->cregs_save_area, 0, 15);
248 save_access_regs((unsigned int *) lc->access_regs_save_area);
249 memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,
253 static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk)
255 struct _lowcore *lc = pcpu->lowcore;
256 struct thread_info *ti = task_thread_info(tsk);
258 lc->kernel_stack = (unsigned long) task_stack_page(tsk)
259 + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
260 lc->thread_info = (unsigned long) task_thread_info(tsk);
261 lc->current_task = (unsigned long) tsk;
262 lc->user_timer = ti->user_timer;
263 lc->system_timer = ti->system_timer;
267 static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data)
269 struct _lowcore *lc = pcpu->lowcore;
271 lc->restart_stack = lc->kernel_stack;
272 lc->restart_fn = (unsigned long) func;
273 lc->restart_data = (unsigned long) data;
274 lc->restart_source = -1UL;
275 pcpu_sigp_retry(pcpu, SIGP_RESTART, 0);
279 * Call function via PSW restart on pcpu and stop the current cpu.
281 static void pcpu_delegate(struct pcpu *pcpu, void (*func)(void *),
282 void *data, unsigned long stack)
284 struct _lowcore *lc = lowcore_ptr[pcpu - pcpu_devices];
285 unsigned long source_cpu = stap();
287 __load_psw_mask(psw_kernel_bits);
288 if (pcpu->address == source_cpu)
289 func(data); /* should not return */
290 /* Stop target cpu (if func returns this stops the current cpu). */
291 pcpu_sigp_retry(pcpu, SIGP_STOP, 0);
292 /* Restart func on the target cpu and stop the current cpu. */
293 mem_assign_absolute(lc->restart_stack, stack);
294 mem_assign_absolute(lc->restart_fn, (unsigned long) func);
295 mem_assign_absolute(lc->restart_data, (unsigned long) data);
296 mem_assign_absolute(lc->restart_source, source_cpu);
298 "0: sigp 0,%0,%2 # sigp restart to target cpu\n"
299 " brc 2,0b # busy, try again\n"
300 "1: sigp 0,%1,%3 # sigp stop to current cpu\n"
301 " brc 2,1b # busy, try again\n"
302 : : "d" (pcpu->address), "d" (source_cpu),
303 "K" (SIGP_RESTART), "K" (SIGP_STOP)
309 * Call function on an online CPU.
311 void smp_call_online_cpu(void (*func)(void *), void *data)
315 /* Use the current cpu if it is online. */
316 pcpu = pcpu_find_address(cpu_online_mask, stap());
318 /* Use the first online cpu. */
319 pcpu = pcpu_devices + cpumask_first(cpu_online_mask);
320 pcpu_delegate(pcpu, func, data, (unsigned long) restart_stack);
324 * Call function on the ipl CPU.
326 void smp_call_ipl_cpu(void (*func)(void *), void *data)
328 pcpu_delegate(&pcpu_devices[0], func, data,
329 pcpu_devices->panic_stack + PAGE_SIZE);
332 int smp_find_processor_id(u16 address)
336 for_each_present_cpu(cpu)
337 if (pcpu_devices[cpu].address == address)
342 int smp_vcpu_scheduled(int cpu)
344 return pcpu_running(pcpu_devices + cpu);
349 if (MACHINE_HAS_DIAG44)
350 asm volatile("diag 0,0,0x44");
353 void smp_yield_cpu(int cpu)
355 if (MACHINE_HAS_DIAG9C)
356 asm volatile("diag %0,0,0x9c"
357 : : "d" (pcpu_devices[cpu].address));
358 else if (MACHINE_HAS_DIAG44)
359 asm volatile("diag 0,0,0x44");
363 * Send cpus emergency shutdown signal. This gives the cpus the
364 * opportunity to complete outstanding interrupts.
366 void smp_emergency_stop(cpumask_t *cpumask)
371 end = get_tod_clock() + (1000000UL << 12);
372 for_each_cpu(cpu, cpumask) {
373 struct pcpu *pcpu = pcpu_devices + cpu;
374 set_bit(ec_stop_cpu, &pcpu->ec_mask);
375 while (__pcpu_sigp(pcpu->address, SIGP_EMERGENCY_SIGNAL,
376 0, NULL) == SIGP_CC_BUSY &&
377 get_tod_clock() < end)
380 while (get_tod_clock() < end) {
381 for_each_cpu(cpu, cpumask)
382 if (pcpu_stopped(pcpu_devices + cpu))
383 cpumask_clear_cpu(cpu, cpumask);
384 if (cpumask_empty(cpumask))
391 * Stop all cpus but the current one.
393 void smp_send_stop(void)
398 /* Disable all interrupts/machine checks */
399 __load_psw_mask(psw_kernel_bits | PSW_MASK_DAT);
400 trace_hardirqs_off();
402 debug_set_critical();
403 cpumask_copy(&cpumask, cpu_online_mask);
404 cpumask_clear_cpu(smp_processor_id(), &cpumask);
406 if (oops_in_progress)
407 smp_emergency_stop(&cpumask);
409 /* stop all processors */
410 for_each_cpu(cpu, &cpumask) {
411 struct pcpu *pcpu = pcpu_devices + cpu;
412 pcpu_sigp_retry(pcpu, SIGP_STOP, 0);
413 while (!pcpu_stopped(pcpu))
419 * Stop the current cpu.
421 void smp_stop_cpu(void)
423 pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0);
428 * This is the main routine where commands issued by other
431 static void do_ext_call_interrupt(struct ext_code ext_code,
432 unsigned int param32, unsigned long param64)
437 cpu = smp_processor_id();
438 if (ext_code.code == 0x1202)
439 inc_irq_stat(IRQEXT_EXC);
441 inc_irq_stat(IRQEXT_EMS);
443 * handle bit signal external calls
445 bits = xchg(&pcpu_devices[cpu].ec_mask, 0);
447 if (test_bit(ec_stop_cpu, &bits))
450 if (test_bit(ec_schedule, &bits))
453 if (test_bit(ec_call_function, &bits))
454 generic_smp_call_function_interrupt();
456 if (test_bit(ec_call_function_single, &bits))
457 generic_smp_call_function_single_interrupt();
461 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
465 for_each_cpu(cpu, mask)
466 pcpu_ec_call(pcpu_devices + cpu, ec_call_function);
469 void arch_send_call_function_single_ipi(int cpu)
471 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
476 * this function sends a 'purge tlb' signal to another CPU.
478 static void smp_ptlb_callback(void *info)
483 void smp_ptlb_all(void)
485 on_each_cpu(smp_ptlb_callback, NULL, 1);
487 EXPORT_SYMBOL(smp_ptlb_all);
488 #endif /* ! CONFIG_64BIT */
491 * this function sends a 'reschedule' IPI to another CPU.
492 * it goes straight through and wastes no time serializing
493 * anything. Worst case is that we lose a reschedule ...
495 void smp_send_reschedule(int cpu)
497 pcpu_ec_call(pcpu_devices + cpu, ec_schedule);
501 * parameter area for the set/clear control bit callbacks
503 struct ec_creg_mask_parms {
505 unsigned long andval;
510 * callback for setting/clearing control bits
512 static void smp_ctl_bit_callback(void *info)
514 struct ec_creg_mask_parms *pp = info;
515 unsigned long cregs[16];
517 __ctl_store(cregs, 0, 15);
518 cregs[pp->cr] = (cregs[pp->cr] & pp->andval) | pp->orval;
519 __ctl_load(cregs, 0, 15);
523 * Set a bit in a control register of all cpus
525 void smp_ctl_set_bit(int cr, int bit)
527 struct ec_creg_mask_parms parms = { 1UL << bit, -1UL, cr };
529 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
531 EXPORT_SYMBOL(smp_ctl_set_bit);
534 * Clear a bit in a control register of all cpus
536 void smp_ctl_clear_bit(int cr, int bit)
538 struct ec_creg_mask_parms parms = { 0, ~(1UL << bit), cr };
540 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
542 EXPORT_SYMBOL(smp_ctl_clear_bit);
544 #if defined(CONFIG_ZFCPDUMP) || defined(CONFIG_CRASH_DUMP)
546 struct save_area *zfcpdump_save_areas[NR_CPUS + 1];
547 EXPORT_SYMBOL_GPL(zfcpdump_save_areas);
549 static void __init smp_get_save_area(int cpu, u16 address)
551 void *lc = pcpu_devices[0].lowcore;
552 struct save_area *save_area;
554 if (is_kdump_kernel())
556 if (!OLDMEM_BASE && (address == boot_cpu_address ||
557 ipl_info.type != IPL_TYPE_FCP_DUMP))
559 if (cpu >= NR_CPUS) {
560 pr_warning("CPU %i exceeds the maximum %i and is excluded "
561 "from the dump\n", cpu, NR_CPUS - 1);
564 save_area = kmalloc(sizeof(struct save_area), GFP_KERNEL);
566 panic("could not allocate memory for save area\n");
567 zfcpdump_save_areas[cpu] = save_area;
568 #ifdef CONFIG_CRASH_DUMP
569 if (address == boot_cpu_address) {
570 /* Copy the registers of the boot cpu. */
571 copy_oldmem_page(1, (void *) save_area, sizeof(*save_area),
572 SAVE_AREA_BASE - PAGE_SIZE, 0);
576 /* Get the registers of a non-boot cpu. */
577 __pcpu_sigp_relax(address, SIGP_STOP_AND_STORE_STATUS, 0, NULL);
578 memcpy_real(save_area, lc + SAVE_AREA_BASE, sizeof(*save_area));
581 int smp_store_status(int cpu)
585 pcpu = pcpu_devices + cpu;
586 if (__pcpu_sigp_relax(pcpu->address, SIGP_STOP_AND_STORE_STATUS,
587 0, NULL) != SIGP_CC_ORDER_CODE_ACCEPTED)
592 #else /* CONFIG_ZFCPDUMP || CONFIG_CRASH_DUMP */
594 static inline void smp_get_save_area(int cpu, u16 address) { }
596 #endif /* CONFIG_ZFCPDUMP || CONFIG_CRASH_DUMP */
598 void smp_cpu_set_polarization(int cpu, int val)
600 pcpu_devices[cpu].polarization = val;
603 int smp_cpu_get_polarization(int cpu)
605 return pcpu_devices[cpu].polarization;
608 static struct sclp_cpu_info *smp_get_cpu_info(void)
610 static int use_sigp_detection;
611 struct sclp_cpu_info *info;
614 info = kzalloc(sizeof(*info), GFP_KERNEL);
615 if (info && (use_sigp_detection || sclp_get_cpu_info(info))) {
616 use_sigp_detection = 1;
617 for (address = 0; address <= MAX_CPU_ADDRESS; address++) {
618 if (__pcpu_sigp_relax(address, SIGP_SENSE, 0, NULL) ==
619 SIGP_CC_NOT_OPERATIONAL)
621 info->cpu[info->configured].address = address;
624 info->combined = info->configured;
629 static int __cpuinit smp_add_present_cpu(int cpu);
631 static int __cpuinit __smp_rescan_cpus(struct sclp_cpu_info *info,
639 cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask);
640 cpu = cpumask_first(&avail);
641 for (i = 0; (i < info->combined) && (cpu < nr_cpu_ids); i++) {
642 if (info->has_cpu_type && info->cpu[i].type != boot_cpu_type)
644 if (pcpu_find_address(cpu_present_mask, info->cpu[i].address))
646 pcpu = pcpu_devices + cpu;
647 pcpu->address = info->cpu[i].address;
648 pcpu->state = (cpu >= info->configured) ?
649 CPU_STATE_STANDBY : CPU_STATE_CONFIGURED;
650 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
651 set_cpu_present(cpu, true);
652 if (sysfs_add && smp_add_present_cpu(cpu) != 0)
653 set_cpu_present(cpu, false);
656 cpu = cpumask_next(cpu, &avail);
661 static void __init smp_detect_cpus(void)
663 unsigned int cpu, c_cpus, s_cpus;
664 struct sclp_cpu_info *info;
666 info = smp_get_cpu_info();
668 panic("smp_detect_cpus failed to allocate memory\n");
669 if (info->has_cpu_type) {
670 for (cpu = 0; cpu < info->combined; cpu++) {
671 if (info->cpu[cpu].address != boot_cpu_address)
673 /* The boot cpu dictates the cpu type. */
674 boot_cpu_type = info->cpu[cpu].type;
679 for (cpu = 0; cpu < info->combined; cpu++) {
680 if (info->has_cpu_type && info->cpu[cpu].type != boot_cpu_type)
682 if (cpu < info->configured) {
683 smp_get_save_area(c_cpus, info->cpu[cpu].address);
688 pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
690 __smp_rescan_cpus(info, 0);
696 * Activate a secondary processor.
698 static void __cpuinit smp_start_secondary(void *cpuvoid)
700 S390_lowcore.last_update_clock = get_tod_clock();
701 S390_lowcore.restart_stack = (unsigned long) restart_stack;
702 S390_lowcore.restart_fn = (unsigned long) do_restart;
703 S390_lowcore.restart_data = 0;
704 S390_lowcore.restart_source = -1UL;
705 restore_access_regs(S390_lowcore.access_regs_save_area);
706 __ctl_load(S390_lowcore.cregs_save_area, 0, 15);
707 __load_psw_mask(psw_kernel_bits | PSW_MASK_DAT);
713 notify_cpu_starting(smp_processor_id());
714 set_cpu_online(smp_processor_id(), true);
715 inc_irq_stat(CPU_RST);
717 /* cpu_idle will call schedule for us */
721 /* Upping and downing of CPUs */
722 int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *tidle)
727 pcpu = pcpu_devices + cpu;
728 if (pcpu->state != CPU_STATE_CONFIGURED)
730 if (pcpu_sigp_retry(pcpu, SIGP_INITIAL_CPU_RESET, 0) !=
731 SIGP_CC_ORDER_CODE_ACCEPTED)
734 rc = pcpu_alloc_lowcore(pcpu, cpu);
737 pcpu_prepare_secondary(pcpu, cpu);
738 pcpu_attach_task(pcpu, tidle);
739 pcpu_start_fn(pcpu, smp_start_secondary, NULL);
740 while (!cpu_online(cpu))
745 static int __init setup_possible_cpus(char *s)
749 if (kstrtoint(s, 0, &max) < 0)
751 init_cpu_possible(cpumask_of(0));
752 for (cpu = 1; cpu < max && cpu < nr_cpu_ids; cpu++)
753 set_cpu_possible(cpu, true);
756 early_param("possible_cpus", setup_possible_cpus);
758 #ifdef CONFIG_HOTPLUG_CPU
760 int __cpu_disable(void)
762 unsigned long cregs[16];
764 set_cpu_online(smp_processor_id(), false);
765 /* Disable pseudo page faults on this cpu. */
767 /* Disable interrupt sources via control register. */
768 __ctl_store(cregs, 0, 15);
769 cregs[0] &= ~0x0000ee70UL; /* disable all external interrupts */
770 cregs[6] &= ~0xff000000UL; /* disable all I/O interrupts */
771 cregs[14] &= ~0x1f000000UL; /* disable most machine checks */
772 __ctl_load(cregs, 0, 15);
776 void __cpu_die(unsigned int cpu)
780 /* Wait until target cpu is down */
781 pcpu = pcpu_devices + cpu;
782 while (!pcpu_stopped(pcpu))
784 pcpu_free_lowcore(pcpu);
785 atomic_dec(&init_mm.context.attach_count);
788 void __noreturn cpu_die(void)
791 pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0);
795 #endif /* CONFIG_HOTPLUG_CPU */
797 void __init smp_prepare_cpus(unsigned int max_cpus)
799 /* request the 0x1201 emergency signal external interrupt */
800 if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0)
801 panic("Couldn't request external interrupt 0x1201");
802 /* request the 0x1202 external call external interrupt */
803 if (register_external_interrupt(0x1202, do_ext_call_interrupt) != 0)
804 panic("Couldn't request external interrupt 0x1202");
808 void __init smp_prepare_boot_cpu(void)
810 struct pcpu *pcpu = pcpu_devices;
812 boot_cpu_address = stap();
813 pcpu->state = CPU_STATE_CONFIGURED;
814 pcpu->address = boot_cpu_address;
815 pcpu->lowcore = (struct _lowcore *)(unsigned long) store_prefix();
816 pcpu->async_stack = S390_lowcore.async_stack - ASYNC_SIZE
817 + STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
818 pcpu->panic_stack = S390_lowcore.panic_stack - PAGE_SIZE
819 + STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
820 S390_lowcore.percpu_offset = __per_cpu_offset[0];
821 smp_cpu_set_polarization(0, POLARIZATION_UNKNOWN);
822 set_cpu_present(0, true);
823 set_cpu_online(0, true);
826 void __init smp_cpus_done(unsigned int max_cpus)
830 void __init smp_setup_processor_id(void)
832 S390_lowcore.cpu_nr = 0;
836 * the frequency of the profiling timer can be changed
837 * by writing a multiplier value into /proc/profile.
839 * usually you want to run this on all CPUs ;)
841 int setup_profiling_timer(unsigned int multiplier)
846 #ifdef CONFIG_HOTPLUG_CPU
847 static ssize_t cpu_configure_show(struct device *dev,
848 struct device_attribute *attr, char *buf)
852 mutex_lock(&smp_cpu_state_mutex);
853 count = sprintf(buf, "%d\n", pcpu_devices[dev->id].state);
854 mutex_unlock(&smp_cpu_state_mutex);
858 static ssize_t cpu_configure_store(struct device *dev,
859 struct device_attribute *attr,
860 const char *buf, size_t count)
866 if (sscanf(buf, "%d %c", &val, &delim) != 1)
868 if (val != 0 && val != 1)
871 mutex_lock(&smp_cpu_state_mutex);
873 /* disallow configuration changes of online cpus and cpu 0 */
875 if (cpu_online(cpu) || cpu == 0)
877 pcpu = pcpu_devices + cpu;
881 if (pcpu->state != CPU_STATE_CONFIGURED)
883 rc = sclp_cpu_deconfigure(pcpu->address);
886 pcpu->state = CPU_STATE_STANDBY;
887 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
888 topology_expect_change();
891 if (pcpu->state != CPU_STATE_STANDBY)
893 rc = sclp_cpu_configure(pcpu->address);
896 pcpu->state = CPU_STATE_CONFIGURED;
897 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
898 topology_expect_change();
904 mutex_unlock(&smp_cpu_state_mutex);
906 return rc ? rc : count;
908 static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
909 #endif /* CONFIG_HOTPLUG_CPU */
911 static ssize_t show_cpu_address(struct device *dev,
912 struct device_attribute *attr, char *buf)
914 return sprintf(buf, "%d\n", pcpu_devices[dev->id].address);
916 static DEVICE_ATTR(address, 0444, show_cpu_address, NULL);
918 static struct attribute *cpu_common_attrs[] = {
919 #ifdef CONFIG_HOTPLUG_CPU
920 &dev_attr_configure.attr,
922 &dev_attr_address.attr,
926 static struct attribute_group cpu_common_attr_group = {
927 .attrs = cpu_common_attrs,
930 static ssize_t show_idle_count(struct device *dev,
931 struct device_attribute *attr, char *buf)
933 struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id);
934 unsigned long long idle_count;
935 unsigned int sequence;
938 sequence = ACCESS_ONCE(idle->sequence);
939 idle_count = ACCESS_ONCE(idle->idle_count);
940 if (ACCESS_ONCE(idle->clock_idle_enter))
942 } while ((sequence & 1) || (idle->sequence != sequence));
943 return sprintf(buf, "%llu\n", idle_count);
945 static DEVICE_ATTR(idle_count, 0444, show_idle_count, NULL);
947 static ssize_t show_idle_time(struct device *dev,
948 struct device_attribute *attr, char *buf)
950 struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id);
951 unsigned long long now, idle_time, idle_enter, idle_exit;
952 unsigned int sequence;
955 now = get_tod_clock();
956 sequence = ACCESS_ONCE(idle->sequence);
957 idle_time = ACCESS_ONCE(idle->idle_time);
958 idle_enter = ACCESS_ONCE(idle->clock_idle_enter);
959 idle_exit = ACCESS_ONCE(idle->clock_idle_exit);
960 } while ((sequence & 1) || (idle->sequence != sequence));
961 idle_time += idle_enter ? ((idle_exit ? : now) - idle_enter) : 0;
962 return sprintf(buf, "%llu\n", idle_time >> 12);
964 static DEVICE_ATTR(idle_time_us, 0444, show_idle_time, NULL);
966 static struct attribute *cpu_online_attrs[] = {
967 &dev_attr_idle_count.attr,
968 &dev_attr_idle_time_us.attr,
972 static struct attribute_group cpu_online_attr_group = {
973 .attrs = cpu_online_attrs,
976 static int __cpuinit smp_cpu_notify(struct notifier_block *self,
977 unsigned long action, void *hcpu)
979 unsigned int cpu = (unsigned int)(long)hcpu;
980 struct cpu *c = &pcpu_devices[cpu].cpu;
981 struct device *s = &c->dev;
984 switch (action & ~CPU_TASKS_FROZEN) {
986 err = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
989 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
992 return notifier_from_errno(err);
995 static int __cpuinit smp_add_present_cpu(int cpu)
997 struct cpu *c = &pcpu_devices[cpu].cpu;
998 struct device *s = &c->dev;
1001 c->hotpluggable = 1;
1002 rc = register_cpu(c, cpu);
1005 rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
1008 if (cpu_online(cpu)) {
1009 rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
1013 rc = topology_cpu_init(c);
1019 if (cpu_online(cpu))
1020 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
1022 sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
1024 #ifdef CONFIG_HOTPLUG_CPU
1031 #ifdef CONFIG_HOTPLUG_CPU
1033 int __ref smp_rescan_cpus(void)
1035 struct sclp_cpu_info *info;
1038 info = smp_get_cpu_info();
1042 mutex_lock(&smp_cpu_state_mutex);
1043 nr = __smp_rescan_cpus(info, 1);
1044 mutex_unlock(&smp_cpu_state_mutex);
1048 topology_schedule_update();
1052 static ssize_t __ref rescan_store(struct device *dev,
1053 struct device_attribute *attr,
1059 rc = smp_rescan_cpus();
1060 return rc ? rc : count;
1062 static DEVICE_ATTR(rescan, 0200, NULL, rescan_store);
1063 #endif /* CONFIG_HOTPLUG_CPU */
1065 static int __init s390_smp_init(void)
1069 hotcpu_notifier(smp_cpu_notify, 0);
1070 #ifdef CONFIG_HOTPLUG_CPU
1071 rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan);
1075 for_each_present_cpu(cpu) {
1076 rc = smp_add_present_cpu(cpu);
1082 subsys_initcall(s390_smp_init);