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>
36 #include <asm/setup.h>
38 #include <asm/tlbflush.h>
39 #include <asm/timer.h>
40 #include <asm/lowcore.h>
43 #include <asm/debug.h>
44 #include <asm/os_info.h>
49 sigp_external_call = 2,
50 sigp_emergency_signal = 3,
54 sigp_stop_and_store_status = 9,
55 sigp_initial_cpu_reset = 11,
58 sigp_store_status_at_address = 14,
59 sigp_store_extended_status_at_address = 15,
60 sigp_set_architecture = 18,
61 sigp_conditional_emergency_signal = 19,
62 sigp_sense_running = 21,
66 sigp_order_code_accepted = 0,
67 sigp_status_stored = 1,
69 sigp_not_operational = 3,
75 ec_call_function_single,
86 struct task_struct *idle; /* idle process for the cpu */
87 struct _lowcore *lowcore; /* lowcore page(s) for the cpu */
88 unsigned long async_stack; /* async stack for the cpu */
89 unsigned long panic_stack; /* panic stack for the cpu */
90 unsigned long ec_mask; /* bit mask for ec_xxx functions */
91 int state; /* physical cpu state */
92 u32 status; /* last status received via sigp */
93 u16 address; /* physical cpu address */
96 static u8 boot_cpu_type;
97 static u16 boot_cpu_address;
98 static struct pcpu pcpu_devices[NR_CPUS];
100 DEFINE_MUTEX(smp_cpu_state_mutex);
103 * Signal processor helper functions.
105 static inline int __pcpu_sigp(u16 addr, u8 order, u32 parm, u32 *status)
107 register unsigned int reg1 asm ("1") = parm;
111 " sigp %1,%2,0(%3)\n"
114 : "=d" (cc), "+d" (reg1) : "d" (addr), "a" (order) : "cc");
115 if (status && cc == 1)
120 static inline int __pcpu_sigp_relax(u16 addr, u8 order, u32 parm, u32 *status)
125 cc = __pcpu_sigp(addr, order, parm, status);
132 static int pcpu_sigp_retry(struct pcpu *pcpu, u8 order, u32 parm)
136 for (retry = 0; ; retry++) {
137 cc = __pcpu_sigp(pcpu->address, order, parm, &pcpu->status);
146 static inline int pcpu_stopped(struct pcpu *pcpu)
148 if (__pcpu_sigp(pcpu->address, sigp_sense,
149 0, &pcpu->status) != sigp_status_stored)
151 /* Check for stopped and check stop state */
152 return !!(pcpu->status & 0x50);
155 static inline int pcpu_running(struct pcpu *pcpu)
157 if (__pcpu_sigp(pcpu->address, sigp_sense_running,
158 0, &pcpu->status) != sigp_status_stored)
160 /* Check for running status */
161 return !(pcpu->status & 0x400);
165 * Find struct pcpu by cpu address.
167 static struct pcpu *pcpu_find_address(const struct cpumask *mask, int address)
171 for_each_cpu(cpu, mask)
172 if (pcpu_devices[cpu].address == address)
173 return pcpu_devices + cpu;
177 static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit)
181 set_bit(ec_bit, &pcpu->ec_mask);
182 order = pcpu_running(pcpu) ?
183 sigp_external_call : sigp_emergency_signal;
184 pcpu_sigp_retry(pcpu, order, 0);
187 static int __cpuinit pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
191 if (pcpu != &pcpu_devices[0]) {
192 pcpu->lowcore = (struct _lowcore *)
193 __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
194 pcpu->async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
195 pcpu->panic_stack = __get_free_page(GFP_KERNEL);
196 if (!pcpu->lowcore || !pcpu->panic_stack || !pcpu->async_stack)
200 memcpy(lc, &S390_lowcore, 512);
201 memset((char *) lc + 512, 0, sizeof(*lc) - 512);
202 lc->async_stack = pcpu->async_stack + ASYNC_SIZE;
203 lc->panic_stack = pcpu->panic_stack + PAGE_SIZE;
206 if (MACHINE_HAS_IEEE) {
207 lc->extended_save_area_addr = get_zeroed_page(GFP_KERNEL);
208 if (!lc->extended_save_area_addr)
212 if (vdso_alloc_per_cpu(lc))
215 lowcore_ptr[cpu] = lc;
216 pcpu_sigp_retry(pcpu, sigp_set_prefix, (u32)(unsigned long) lc);
219 if (pcpu != &pcpu_devices[0]) {
220 free_page(pcpu->panic_stack);
221 free_pages(pcpu->async_stack, ASYNC_ORDER);
222 free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
227 static void pcpu_free_lowcore(struct pcpu *pcpu)
229 pcpu_sigp_retry(pcpu, sigp_set_prefix, 0);
230 lowcore_ptr[pcpu - pcpu_devices] = NULL;
232 if (MACHINE_HAS_IEEE) {
233 struct _lowcore *lc = pcpu->lowcore;
235 free_page((unsigned long) lc->extended_save_area_addr);
236 lc->extended_save_area_addr = 0;
239 vdso_free_per_cpu(pcpu->lowcore);
241 if (pcpu != &pcpu_devices[0]) {
242 free_page(pcpu->panic_stack);
243 free_pages(pcpu->async_stack, ASYNC_ORDER);
244 free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
248 static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu)
250 struct _lowcore *lc = pcpu->lowcore;
252 atomic_inc(&init_mm.context.attach_count);
254 lc->percpu_offset = __per_cpu_offset[cpu];
255 lc->kernel_asce = S390_lowcore.kernel_asce;
256 lc->machine_flags = S390_lowcore.machine_flags;
257 lc->ftrace_func = S390_lowcore.ftrace_func;
258 lc->user_timer = lc->system_timer = lc->steal_timer = 0;
259 __ctl_store(lc->cregs_save_area, 0, 15);
260 save_access_regs((unsigned int *) lc->access_regs_save_area);
261 memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,
265 static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk)
267 struct _lowcore *lc = pcpu->lowcore;
268 struct thread_info *ti = task_thread_info(tsk);
270 lc->kernel_stack = (unsigned long) task_stack_page(tsk) + THREAD_SIZE;
271 lc->thread_info = (unsigned long) task_thread_info(tsk);
272 lc->current_task = (unsigned long) tsk;
273 lc->user_timer = ti->user_timer;
274 lc->system_timer = ti->system_timer;
278 static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data)
280 struct _lowcore *lc = pcpu->lowcore;
282 lc->restart_stack = lc->kernel_stack;
283 lc->restart_fn = (unsigned long) func;
284 lc->restart_data = (unsigned long) data;
285 lc->restart_source = -1UL;
286 pcpu_sigp_retry(pcpu, sigp_restart, 0);
290 * Call function via PSW restart on pcpu and stop the current cpu.
292 static void pcpu_delegate(struct pcpu *pcpu, void (*func)(void *),
293 void *data, unsigned long stack)
295 struct _lowcore *lc = pcpu->lowcore;
296 unsigned short this_cpu;
298 __load_psw_mask(psw_kernel_bits);
300 if (pcpu->address == this_cpu)
301 func(data); /* should not return */
302 /* Stop target cpu (if func returns this stops the current cpu). */
303 pcpu_sigp_retry(pcpu, sigp_stop, 0);
304 /* Restart func on the target cpu and stop the current cpu. */
305 lc->restart_stack = stack;
306 lc->restart_fn = (unsigned long) func;
307 lc->restart_data = (unsigned long) data;
308 lc->restart_source = (unsigned long) this_cpu;
310 "0: sigp 0,%0,6 # sigp restart to target cpu\n"
311 " brc 2,0b # busy, try again\n"
312 "1: sigp 0,%1,5 # sigp stop to current cpu\n"
313 " brc 2,1b # busy, try again\n"
314 : : "d" (pcpu->address), "d" (this_cpu) : "0", "1", "cc");
319 * Call function on an online CPU.
321 void smp_call_online_cpu(void (*func)(void *), void *data)
325 /* Use the current cpu if it is online. */
326 pcpu = pcpu_find_address(cpu_online_mask, stap());
328 /* Use the first online cpu. */
329 pcpu = pcpu_devices + cpumask_first(cpu_online_mask);
330 pcpu_delegate(pcpu, func, data, (unsigned long) restart_stack);
334 * Call function on the ipl CPU.
336 void smp_call_ipl_cpu(void (*func)(void *), void *data)
338 pcpu_delegate(&pcpu_devices[0], func, data,
339 pcpu_devices->panic_stack + PAGE_SIZE);
342 int smp_find_processor_id(u16 address)
346 for_each_present_cpu(cpu)
347 if (pcpu_devices[cpu].address == address)
352 int smp_vcpu_scheduled(int cpu)
354 return pcpu_running(pcpu_devices + cpu);
359 if (MACHINE_HAS_DIAG44)
360 asm volatile("diag 0,0,0x44");
363 void smp_yield_cpu(int cpu)
365 if (MACHINE_HAS_DIAG9C)
366 asm volatile("diag %0,0,0x9c"
367 : : "d" (pcpu_devices[cpu].address));
368 else if (MACHINE_HAS_DIAG44)
369 asm volatile("diag 0,0,0x44");
373 * Send cpus emergency shutdown signal. This gives the cpus the
374 * opportunity to complete outstanding interrupts.
376 void smp_emergency_stop(cpumask_t *cpumask)
381 end = get_clock() + (1000000UL << 12);
382 for_each_cpu(cpu, cpumask) {
383 struct pcpu *pcpu = pcpu_devices + cpu;
384 set_bit(ec_stop_cpu, &pcpu->ec_mask);
385 while (__pcpu_sigp(pcpu->address, sigp_emergency_signal,
386 0, NULL) == sigp_busy &&
390 while (get_clock() < end) {
391 for_each_cpu(cpu, cpumask)
392 if (pcpu_stopped(pcpu_devices + cpu))
393 cpumask_clear_cpu(cpu, cpumask);
394 if (cpumask_empty(cpumask))
401 * Stop all cpus but the current one.
403 void smp_send_stop(void)
408 /* Disable all interrupts/machine checks */
409 __load_psw_mask(psw_kernel_bits | PSW_MASK_DAT);
410 trace_hardirqs_off();
412 debug_set_critical();
413 cpumask_copy(&cpumask, cpu_online_mask);
414 cpumask_clear_cpu(smp_processor_id(), &cpumask);
416 if (oops_in_progress)
417 smp_emergency_stop(&cpumask);
419 /* stop all processors */
420 for_each_cpu(cpu, &cpumask) {
421 struct pcpu *pcpu = pcpu_devices + cpu;
422 pcpu_sigp_retry(pcpu, sigp_stop, 0);
423 while (!pcpu_stopped(pcpu))
429 * Stop the current cpu.
431 void smp_stop_cpu(void)
433 pcpu_sigp_retry(pcpu_devices + smp_processor_id(), sigp_stop, 0);
438 * This is the main routine where commands issued by other
441 static void do_ext_call_interrupt(struct ext_code ext_code,
442 unsigned int param32, unsigned long param64)
447 cpu = smp_processor_id();
448 if (ext_code.code == 0x1202)
449 kstat_cpu(cpu).irqs[EXTINT_EXC]++;
451 kstat_cpu(cpu).irqs[EXTINT_EMS]++;
453 * handle bit signal external calls
455 bits = xchg(&pcpu_devices[cpu].ec_mask, 0);
457 if (test_bit(ec_stop_cpu, &bits))
460 if (test_bit(ec_schedule, &bits))
463 if (test_bit(ec_call_function, &bits))
464 generic_smp_call_function_interrupt();
466 if (test_bit(ec_call_function_single, &bits))
467 generic_smp_call_function_single_interrupt();
471 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
475 for_each_cpu(cpu, mask)
476 pcpu_ec_call(pcpu_devices + cpu, ec_call_function);
479 void arch_send_call_function_single_ipi(int cpu)
481 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
486 * this function sends a 'purge tlb' signal to another CPU.
488 static void smp_ptlb_callback(void *info)
493 void smp_ptlb_all(void)
495 on_each_cpu(smp_ptlb_callback, NULL, 1);
497 EXPORT_SYMBOL(smp_ptlb_all);
498 #endif /* ! CONFIG_64BIT */
501 * this function sends a 'reschedule' IPI to another CPU.
502 * it goes straight through and wastes no time serializing
503 * anything. Worst case is that we lose a reschedule ...
505 void smp_send_reschedule(int cpu)
507 pcpu_ec_call(pcpu_devices + cpu, ec_schedule);
511 * parameter area for the set/clear control bit callbacks
513 struct ec_creg_mask_parms {
515 unsigned long andval;
520 * callback for setting/clearing control bits
522 static void smp_ctl_bit_callback(void *info)
524 struct ec_creg_mask_parms *pp = info;
525 unsigned long cregs[16];
527 __ctl_store(cregs, 0, 15);
528 cregs[pp->cr] = (cregs[pp->cr] & pp->andval) | pp->orval;
529 __ctl_load(cregs, 0, 15);
533 * Set a bit in a control register of all cpus
535 void smp_ctl_set_bit(int cr, int bit)
537 struct ec_creg_mask_parms parms = { 1UL << bit, -1UL, cr };
539 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
541 EXPORT_SYMBOL(smp_ctl_set_bit);
544 * Clear a bit in a control register of all cpus
546 void smp_ctl_clear_bit(int cr, int bit)
548 struct ec_creg_mask_parms parms = { 0, ~(1UL << bit), cr };
550 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
552 EXPORT_SYMBOL(smp_ctl_clear_bit);
554 #if defined(CONFIG_ZFCPDUMP) || defined(CONFIG_CRASH_DUMP)
556 struct save_area *zfcpdump_save_areas[NR_CPUS + 1];
557 EXPORT_SYMBOL_GPL(zfcpdump_save_areas);
559 static void __init smp_get_save_area(int cpu, u16 address)
561 void *lc = pcpu_devices[0].lowcore;
562 struct save_area *save_area;
564 if (is_kdump_kernel())
566 if (!OLDMEM_BASE && (address == boot_cpu_address ||
567 ipl_info.type != IPL_TYPE_FCP_DUMP))
569 if (cpu >= NR_CPUS) {
570 pr_warning("CPU %i exceeds the maximum %i and is excluded "
571 "from the dump\n", cpu, NR_CPUS - 1);
574 save_area = kmalloc(sizeof(struct save_area), GFP_KERNEL);
576 panic("could not allocate memory for save area\n");
577 zfcpdump_save_areas[cpu] = save_area;
578 #ifdef CONFIG_CRASH_DUMP
579 if (address == boot_cpu_address) {
580 /* Copy the registers of the boot cpu. */
581 copy_oldmem_page(1, (void *) save_area, sizeof(*save_area),
582 SAVE_AREA_BASE - PAGE_SIZE, 0);
586 /* Get the registers of a non-boot cpu. */
587 __pcpu_sigp_relax(address, sigp_stop_and_store_status, 0, NULL);
588 memcpy_real(save_area, lc + SAVE_AREA_BASE, sizeof(*save_area));
591 int smp_store_status(int cpu)
595 pcpu = pcpu_devices + cpu;
596 if (__pcpu_sigp_relax(pcpu->address, sigp_stop_and_store_status,
597 0, NULL) != sigp_order_code_accepted)
602 #else /* CONFIG_ZFCPDUMP || CONFIG_CRASH_DUMP */
604 static inline void smp_get_save_area(int cpu, u16 address) { }
606 #endif /* CONFIG_ZFCPDUMP || CONFIG_CRASH_DUMP */
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_not_operational)
621 info->cpu[info->configured].address = address;
624 info->combined = info->configured;
629 static int __devinit smp_add_present_cpu(int cpu);
631 static int __devinit __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 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_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());
715 set_cpu_online(smp_processor_id(), true);
718 /* cpu_idle will call schedule for us */
723 struct work_struct work;
724 struct task_struct *idle;
725 struct completion done;
729 static void __cpuinit smp_fork_idle(struct work_struct *work)
731 struct create_idle *c_idle;
733 c_idle = container_of(work, struct create_idle, work);
734 c_idle->idle = fork_idle(c_idle->cpu);
735 complete(&c_idle->done);
738 /* Upping and downing of CPUs */
739 int __cpuinit __cpu_up(unsigned int cpu)
741 struct create_idle c_idle;
745 pcpu = pcpu_devices + cpu;
746 if (pcpu->state != CPU_STATE_CONFIGURED)
748 if (pcpu_sigp_retry(pcpu, sigp_initial_cpu_reset, 0) !=
749 sigp_order_code_accepted)
752 c_idle.done = COMPLETION_INITIALIZER_ONSTACK(c_idle.done);
753 INIT_WORK_ONSTACK(&c_idle.work, smp_fork_idle);
755 schedule_work(&c_idle.work);
756 wait_for_completion(&c_idle.done);
757 if (IS_ERR(c_idle.idle))
758 return PTR_ERR(c_idle.idle);
759 pcpu->idle = c_idle.idle;
761 init_idle(pcpu->idle, cpu);
762 rc = pcpu_alloc_lowcore(pcpu, cpu);
765 pcpu_prepare_secondary(pcpu, cpu);
766 pcpu_attach_task(pcpu, pcpu->idle);
767 pcpu_start_fn(pcpu, smp_start_secondary, NULL);
768 while (!cpu_online(cpu))
773 static int __init setup_possible_cpus(char *s)
777 if (kstrtoint(s, 0, &max) < 0)
779 init_cpu_possible(cpumask_of(0));
780 for (cpu = 1; cpu < max && cpu < nr_cpu_ids; cpu++)
781 set_cpu_possible(cpu, true);
784 early_param("possible_cpus", setup_possible_cpus);
786 #ifdef CONFIG_HOTPLUG_CPU
788 int __cpu_disable(void)
790 unsigned long cregs[16];
792 set_cpu_online(smp_processor_id(), false);
793 /* Disable pseudo page faults on this cpu. */
795 /* Disable interrupt sources via control register. */
796 __ctl_store(cregs, 0, 15);
797 cregs[0] &= ~0x0000ee70UL; /* disable all external interrupts */
798 cregs[6] &= ~0xff000000UL; /* disable all I/O interrupts */
799 cregs[14] &= ~0x1f000000UL; /* disable most machine checks */
800 __ctl_load(cregs, 0, 15);
804 void __cpu_die(unsigned int cpu)
808 /* Wait until target cpu is down */
809 pcpu = pcpu_devices + cpu;
810 while (!pcpu_stopped(pcpu))
812 pcpu_free_lowcore(pcpu);
813 atomic_dec(&init_mm.context.attach_count);
816 void __noreturn cpu_die(void)
819 pcpu_sigp_retry(pcpu_devices + smp_processor_id(), sigp_stop, 0);
823 #endif /* CONFIG_HOTPLUG_CPU */
825 static void smp_call_os_info_init_fn(void)
827 int (*init_fn)(void);
830 init_fn = os_info_old_entry(OS_INFO_INIT_FN, &size);
836 void __init smp_prepare_cpus(unsigned int max_cpus)
838 /* request the 0x1201 emergency signal external interrupt */
839 if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0)
840 panic("Couldn't request external interrupt 0x1201");
841 /* request the 0x1202 external call external interrupt */
842 if (register_external_interrupt(0x1202, do_ext_call_interrupt) != 0)
843 panic("Couldn't request external interrupt 0x1202");
844 smp_call_os_info_init_fn();
848 void __init smp_prepare_boot_cpu(void)
850 struct pcpu *pcpu = pcpu_devices;
852 boot_cpu_address = stap();
853 pcpu->idle = current;
854 pcpu->state = CPU_STATE_CONFIGURED;
855 pcpu->address = boot_cpu_address;
856 pcpu->lowcore = (struct _lowcore *)(unsigned long) store_prefix();
857 pcpu->async_stack = S390_lowcore.async_stack - ASYNC_SIZE;
858 pcpu->panic_stack = S390_lowcore.panic_stack - PAGE_SIZE;
859 S390_lowcore.percpu_offset = __per_cpu_offset[0];
860 cpu_set_polarization(0, POLARIZATION_UNKNOWN);
861 set_cpu_present(0, true);
862 set_cpu_online(0, true);
865 void __init smp_cpus_done(unsigned int max_cpus)
869 void __init smp_setup_processor_id(void)
871 S390_lowcore.cpu_nr = 0;
875 * the frequency of the profiling timer can be changed
876 * by writing a multiplier value into /proc/profile.
878 * usually you want to run this on all CPUs ;)
880 int setup_profiling_timer(unsigned int multiplier)
885 #ifdef CONFIG_HOTPLUG_CPU
886 static ssize_t cpu_configure_show(struct device *dev,
887 struct device_attribute *attr, char *buf)
891 mutex_lock(&smp_cpu_state_mutex);
892 count = sprintf(buf, "%d\n", pcpu_devices[dev->id].state);
893 mutex_unlock(&smp_cpu_state_mutex);
897 static ssize_t cpu_configure_store(struct device *dev,
898 struct device_attribute *attr,
899 const char *buf, size_t count)
905 if (sscanf(buf, "%d %c", &val, &delim) != 1)
907 if (val != 0 && val != 1)
910 mutex_lock(&smp_cpu_state_mutex);
912 /* disallow configuration changes of online cpus and cpu 0 */
914 if (cpu_online(cpu) || cpu == 0)
916 pcpu = pcpu_devices + cpu;
920 if (pcpu->state != CPU_STATE_CONFIGURED)
922 rc = sclp_cpu_deconfigure(pcpu->address);
925 pcpu->state = CPU_STATE_STANDBY;
926 cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
927 topology_expect_change();
930 if (pcpu->state != CPU_STATE_STANDBY)
932 rc = sclp_cpu_configure(pcpu->address);
935 pcpu->state = CPU_STATE_CONFIGURED;
936 cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
937 topology_expect_change();
943 mutex_unlock(&smp_cpu_state_mutex);
945 return rc ? rc : count;
947 static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
948 #endif /* CONFIG_HOTPLUG_CPU */
950 static ssize_t show_cpu_address(struct device *dev,
951 struct device_attribute *attr, char *buf)
953 return sprintf(buf, "%d\n", pcpu_devices[dev->id].address);
955 static DEVICE_ATTR(address, 0444, show_cpu_address, NULL);
957 static struct attribute *cpu_common_attrs[] = {
958 #ifdef CONFIG_HOTPLUG_CPU
959 &dev_attr_configure.attr,
961 &dev_attr_address.attr,
965 static struct attribute_group cpu_common_attr_group = {
966 .attrs = cpu_common_attrs,
969 static ssize_t show_capability(struct device *dev,
970 struct device_attribute *attr, char *buf)
972 unsigned int capability;
975 rc = get_cpu_capability(&capability);
978 return sprintf(buf, "%u\n", capability);
980 static DEVICE_ATTR(capability, 0444, show_capability, NULL);
982 static ssize_t show_idle_count(struct device *dev,
983 struct device_attribute *attr, char *buf)
985 struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id);
986 unsigned long long idle_count;
987 unsigned int sequence;
990 sequence = ACCESS_ONCE(idle->sequence);
991 idle_count = ACCESS_ONCE(idle->idle_count);
992 if (ACCESS_ONCE(idle->idle_enter))
994 } while ((sequence & 1) || (idle->sequence != sequence));
995 return sprintf(buf, "%llu\n", idle_count);
997 static DEVICE_ATTR(idle_count, 0444, show_idle_count, NULL);
999 static ssize_t show_idle_time(struct device *dev,
1000 struct device_attribute *attr, char *buf)
1002 struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id);
1003 unsigned long long now, idle_time, idle_enter, idle_exit;
1004 unsigned int sequence;
1008 sequence = ACCESS_ONCE(idle->sequence);
1009 idle_time = ACCESS_ONCE(idle->idle_time);
1010 idle_enter = ACCESS_ONCE(idle->idle_enter);
1011 idle_exit = ACCESS_ONCE(idle->idle_exit);
1012 } while ((sequence & 1) || (idle->sequence != sequence));
1013 idle_time += idle_enter ? ((idle_exit ? : now) - idle_enter) : 0;
1014 return sprintf(buf, "%llu\n", idle_time >> 12);
1016 static DEVICE_ATTR(idle_time_us, 0444, show_idle_time, NULL);
1018 static struct attribute *cpu_online_attrs[] = {
1019 &dev_attr_capability.attr,
1020 &dev_attr_idle_count.attr,
1021 &dev_attr_idle_time_us.attr,
1025 static struct attribute_group cpu_online_attr_group = {
1026 .attrs = cpu_online_attrs,
1029 static int __cpuinit smp_cpu_notify(struct notifier_block *self,
1030 unsigned long action, void *hcpu)
1032 unsigned int cpu = (unsigned int)(long)hcpu;
1033 struct cpu *c = &pcpu_devices[cpu].cpu;
1034 struct device *s = &c->dev;
1035 struct s390_idle_data *idle;
1040 case CPU_ONLINE_FROZEN:
1041 idle = &per_cpu(s390_idle, cpu);
1042 memset(idle, 0, sizeof(struct s390_idle_data));
1043 err = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
1046 case CPU_DEAD_FROZEN:
1047 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
1050 return notifier_from_errno(err);
1053 static struct notifier_block __cpuinitdata smp_cpu_nb = {
1054 .notifier_call = smp_cpu_notify,
1057 static int __devinit smp_add_present_cpu(int cpu)
1059 struct cpu *c = &pcpu_devices[cpu].cpu;
1060 struct device *s = &c->dev;
1063 c->hotpluggable = 1;
1064 rc = register_cpu(c, cpu);
1067 rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
1070 if (cpu_online(cpu)) {
1071 rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
1075 rc = topology_cpu_init(c);
1081 if (cpu_online(cpu))
1082 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
1084 sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
1086 #ifdef CONFIG_HOTPLUG_CPU
1093 #ifdef CONFIG_HOTPLUG_CPU
1095 int __ref smp_rescan_cpus(void)
1097 struct sclp_cpu_info *info;
1100 info = smp_get_cpu_info();
1104 mutex_lock(&smp_cpu_state_mutex);
1105 nr = __smp_rescan_cpus(info, 1);
1106 mutex_unlock(&smp_cpu_state_mutex);
1110 topology_schedule_update();
1114 static ssize_t __ref rescan_store(struct device *dev,
1115 struct device_attribute *attr,
1121 rc = smp_rescan_cpus();
1122 return rc ? rc : count;
1124 static DEVICE_ATTR(rescan, 0200, NULL, rescan_store);
1125 #endif /* CONFIG_HOTPLUG_CPU */
1127 static int __init s390_smp_init(void)
1131 register_cpu_notifier(&smp_cpu_nb);
1132 #ifdef CONFIG_HOTPLUG_CPU
1133 rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan);
1137 for_each_present_cpu(cpu) {
1138 rc = smp_add_present_cpu(cpu);
1144 subsys_initcall(s390_smp_init);