2 * arch/s390/kernel/smp.c
4 * Copyright (C) IBM Corp. 1999,2006
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/spinlock.h>
27 #include <linux/kernel_stat.h>
28 #include <linux/smp_lock.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>
35 #include <asm/setup.h>
37 #include <asm/pgalloc.h>
39 #include <asm/s390_ext.h>
40 #include <asm/cpcmd.h>
41 #include <asm/tlbflush.h>
42 #include <asm/timer.h>
44 extern volatile int __cpu_logical_map[];
47 * An array with a pointer the lowcore of every CPU.
50 struct _lowcore *lowcore_ptr[NR_CPUS];
52 cpumask_t cpu_online_map = CPU_MASK_NONE;
53 cpumask_t cpu_possible_map = CPU_MASK_NONE;
55 static struct task_struct *current_set[NR_CPUS];
57 static void smp_ext_bitcall(int, ec_bit_sig);
60 * Structure and data for __smp_call_function_map(). This is designed to
61 * minimise static memory requirements. It also looks cleaner.
63 static DEFINE_SPINLOCK(call_lock);
65 struct call_data_struct {
66 void (*func) (void *info);
73 static struct call_data_struct * call_data;
76 * 'Call function' interrupt callback
78 static void do_call_function(void)
80 void (*func) (void *info) = call_data->func;
81 void *info = call_data->info;
82 int wait = call_data->wait;
84 cpu_set(smp_processor_id(), call_data->started);
87 cpu_set(smp_processor_id(), call_data->finished);;
90 static void __smp_call_function_map(void (*func) (void *info), void *info,
91 int nonatomic, int wait, cpumask_t map)
93 struct call_data_struct data;
97 * Can deadlock when interrupts are disabled or if in wrong context.
99 WARN_ON(irqs_disabled() || in_irq());
102 * Check for local function call. We have to have the same call order
103 * as in on_each_cpu() because of machine_restart_smp().
105 if (cpu_isset(smp_processor_id(), map)) {
107 cpu_clear(smp_processor_id(), map);
110 cpus_and(map, map, cpu_online_map);
116 data.started = CPU_MASK_NONE;
119 data.finished = CPU_MASK_NONE;
121 spin_lock_bh(&call_lock);
124 for_each_cpu_mask(cpu, map)
125 smp_ext_bitcall(cpu, ec_call_function);
127 /* Wait for response */
128 while (!cpus_equal(map, data.started))
132 while (!cpus_equal(map, data.finished))
135 spin_unlock_bh(&call_lock);
146 * @func: the function to run; this must be fast and non-blocking
147 * @info: an arbitrary pointer to pass to the function
149 * @wait: if true, wait (atomically) until function has completed on other CPUs
151 * Run a function on all other CPUs.
153 * You must not call this function with disabled interrupts or from a
154 * hardware interrupt handler. You may call it from a bottom half.
156 int smp_call_function(void (*func) (void *info), void *info, int nonatomic,
162 map = cpu_online_map;
163 cpu_clear(smp_processor_id(), map);
164 __smp_call_function_map(func, info, nonatomic, wait, map);
168 EXPORT_SYMBOL(smp_call_function);
171 * smp_call_function_on:
172 * @func: the function to run; this must be fast and non-blocking
173 * @info: an arbitrary pointer to pass to the function
175 * @wait: if true, wait (atomically) until function has completed on other CPUs
176 * @cpu: the CPU where func should run
178 * Run a function on one processor.
180 * You must not call this function with disabled interrupts or from a
181 * hardware interrupt handler. You may call it from a bottom half.
183 int smp_call_function_on(void (*func) (void *info), void *info, int nonatomic,
186 cpumask_t map = CPU_MASK_NONE;
190 __smp_call_function_map(func, info, nonatomic, wait, map);
194 EXPORT_SYMBOL(smp_call_function_on);
196 static void do_send_stop(void)
200 /* stop all processors */
201 for_each_online_cpu(cpu) {
202 if (cpu == smp_processor_id())
205 rc = signal_processor(cpu, sigp_stop);
206 } while (rc == sigp_busy);
210 static void do_store_status(void)
214 /* store status of all processors in their lowcores (real 0) */
215 for_each_online_cpu(cpu) {
216 if (cpu == smp_processor_id())
219 rc = signal_processor_p(
220 (__u32)(unsigned long) lowcore_ptr[cpu], cpu,
221 sigp_store_status_at_address);
222 } while(rc == sigp_busy);
226 static void do_wait_for_stop(void)
230 /* Wait for all other cpus to enter stopped state */
231 for_each_online_cpu(cpu) {
232 if (cpu == smp_processor_id())
234 while(!smp_cpu_not_running(cpu))
240 * this function sends a 'stop' sigp to all other CPUs in the system.
241 * it goes straight through.
243 void smp_send_stop(void)
245 /* Disable all interrupts/machine checks */
246 __load_psw_mask(psw_kernel_bits & ~PSW_MASK_MCHECK);
248 /* write magic number to zero page (absolute 0) */
249 lowcore_ptr[smp_processor_id()]->panic_magic = __PANIC_MAGIC;
251 /* stop other processors. */
254 /* wait until other processors are stopped */
257 /* store status of other processors. */
262 * Reboot, halt and power_off routines for SMP.
265 void machine_restart_smp(char * __unused)
271 void machine_halt_smp(void)
274 if (MACHINE_IS_VM && strlen(vmhalt_cmd) > 0)
275 __cpcmd(vmhalt_cmd, NULL, 0, NULL);
276 signal_processor(smp_processor_id(), sigp_stop_and_store_status);
280 void machine_power_off_smp(void)
283 if (MACHINE_IS_VM && strlen(vmpoff_cmd) > 0)
284 __cpcmd(vmpoff_cmd, NULL, 0, NULL);
285 signal_processor(smp_processor_id(), sigp_stop_and_store_status);
290 * This is the main routine where commands issued by other
294 static void do_ext_call_interrupt(__u16 code)
299 * handle bit signal external calls
301 * For the ec_schedule signal we have to do nothing. All the work
302 * is done automatically when we return from the interrupt.
304 bits = xchg(&S390_lowcore.ext_call_fast, 0);
306 if (test_bit(ec_call_function, &bits))
311 * Send an external call sigp to another cpu and return without waiting
312 * for its completion.
314 static void smp_ext_bitcall(int cpu, ec_bit_sig sig)
317 * Set signaling bit in lowcore of target cpu and kick it
319 set_bit(sig, (unsigned long *) &lowcore_ptr[cpu]->ext_call_fast);
320 while(signal_processor(cpu, sigp_emergency_signal) == sigp_busy)
326 * this function sends a 'purge tlb' signal to another CPU.
328 void smp_ptlb_callback(void *info)
333 void smp_ptlb_all(void)
335 on_each_cpu(smp_ptlb_callback, NULL, 0, 1);
337 EXPORT_SYMBOL(smp_ptlb_all);
338 #endif /* ! CONFIG_64BIT */
341 * this function sends a 'reschedule' IPI to another CPU.
342 * it goes straight through and wastes no time serializing
343 * anything. Worst case is that we lose a reschedule ...
345 void smp_send_reschedule(int cpu)
347 smp_ext_bitcall(cpu, ec_schedule);
351 * parameter area for the set/clear control bit callbacks
353 struct ec_creg_mask_parms {
354 unsigned long orvals[16];
355 unsigned long andvals[16];
359 * callback for setting/clearing control bits
361 static void smp_ctl_bit_callback(void *info) {
362 struct ec_creg_mask_parms *pp = info;
363 unsigned long cregs[16];
366 __ctl_store(cregs, 0, 15);
367 for (i = 0; i <= 15; i++)
368 cregs[i] = (cregs[i] & pp->andvals[i]) | pp->orvals[i];
369 __ctl_load(cregs, 0, 15);
373 * Set a bit in a control register of all cpus
375 void smp_ctl_set_bit(int cr, int bit)
377 struct ec_creg_mask_parms parms;
379 memset(&parms.orvals, 0, sizeof(parms.orvals));
380 memset(&parms.andvals, 0xff, sizeof(parms.andvals));
381 parms.orvals[cr] = 1 << bit;
382 on_each_cpu(smp_ctl_bit_callback, &parms, 0, 1);
386 * Clear a bit in a control register of all cpus
388 void smp_ctl_clear_bit(int cr, int bit)
390 struct ec_creg_mask_parms parms;
392 memset(&parms.orvals, 0, sizeof(parms.orvals));
393 memset(&parms.andvals, 0xff, sizeof(parms.andvals));
394 parms.andvals[cr] = ~(1L << bit);
395 on_each_cpu(smp_ctl_bit_callback, &parms, 0, 1);
399 * Lets check how many CPUs we have.
403 __init smp_count_cpus(void)
405 unsigned int cpu, num_cpus;
409 * cpu 0 is the boot cpu. See smp_prepare_boot_cpu.
412 boot_cpu_addr = S390_lowcore.cpu_data.cpu_addr;
413 current_thread_info()->cpu = 0;
415 for (cpu = 0; cpu <= 65535; cpu++) {
416 if ((__u16) cpu == boot_cpu_addr)
418 __cpu_logical_map[1] = (__u16) cpu;
419 if (signal_processor(1, sigp_sense) ==
420 sigp_not_operational)
425 printk("Detected %d CPU's\n",(int) num_cpus);
426 printk("Boot cpu address %2X\n", boot_cpu_addr);
432 * Activate a secondary processor.
434 int __devinit start_secondary(void *cpuvoid)
439 /* Enable TOD clock interrupts on the secondary cpu. */
441 #ifdef CONFIG_VIRT_TIMER
442 /* Enable cpu timer interrupts on the secondary cpu. */
445 /* Enable pfault pseudo page faults on this cpu. */
448 /* Mark this cpu as online */
449 cpu_set(smp_processor_id(), cpu_online_map);
450 /* Switch on interrupts */
452 /* Print info about this processor */
453 print_cpu_info(&S390_lowcore.cpu_data);
454 /* cpu_idle will call schedule for us */
459 static void __init smp_create_idle(unsigned int cpu)
461 struct task_struct *p;
464 * don't care about the psw and regs settings since we'll never
465 * reschedule the forked task.
469 panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p));
470 current_set[cpu] = p;
473 /* Reserving and releasing of CPUs */
475 static DEFINE_SPINLOCK(smp_reserve_lock);
476 static int smp_cpu_reserved[NR_CPUS];
479 smp_get_cpu(cpumask_t cpu_mask)
484 spin_lock_irqsave(&smp_reserve_lock, flags);
485 /* Try to find an already reserved cpu. */
486 for_each_cpu_mask(cpu, cpu_mask) {
487 if (smp_cpu_reserved[cpu] != 0) {
488 smp_cpu_reserved[cpu]++;
493 /* Reserve a new cpu from cpu_mask. */
494 for_each_cpu_mask(cpu, cpu_mask) {
495 if (cpu_online(cpu)) {
496 smp_cpu_reserved[cpu]++;
502 spin_unlock_irqrestore(&smp_reserve_lock, flags);
511 spin_lock_irqsave(&smp_reserve_lock, flags);
512 smp_cpu_reserved[cpu]--;
513 spin_unlock_irqrestore(&smp_reserve_lock, flags);
521 /* Check for stopped state */
522 if (signal_processor_ps(&status, 0, cpu, sigp_sense) == sigp_status_stored) {
529 /* Upping and downing of CPUs */
532 __cpu_up(unsigned int cpu)
534 struct task_struct *idle;
535 struct _lowcore *cpu_lowcore;
536 struct stack_frame *sf;
540 for (curr_cpu = 0; curr_cpu <= 65535; curr_cpu++) {
541 __cpu_logical_map[cpu] = (__u16) curr_cpu;
542 if (cpu_stopped(cpu))
546 if (!cpu_stopped(cpu))
549 ccode = signal_processor_p((__u32)(unsigned long)(lowcore_ptr[cpu]),
550 cpu, sigp_set_prefix);
552 printk("sigp_set_prefix failed for cpu %d "
553 "with condition code %d\n",
554 (int) cpu, (int) ccode);
558 idle = current_set[cpu];
559 cpu_lowcore = lowcore_ptr[cpu];
560 cpu_lowcore->kernel_stack = (unsigned long)
561 task_stack_page(idle) + (THREAD_SIZE);
562 sf = (struct stack_frame *) (cpu_lowcore->kernel_stack
563 - sizeof(struct pt_regs)
564 - sizeof(struct stack_frame));
565 memset(sf, 0, sizeof(struct stack_frame));
566 sf->gprs[9] = (unsigned long) sf;
567 cpu_lowcore->save_area[15] = (unsigned long) sf;
568 __ctl_store(cpu_lowcore->cregs_save_area[0], 0, 15);
571 : : "a" (&cpu_lowcore->access_regs_save_area) : "memory");
572 cpu_lowcore->percpu_offset = __per_cpu_offset[cpu];
573 cpu_lowcore->current_task = (unsigned long) idle;
574 cpu_lowcore->cpu_data.cpu_nr = cpu;
577 while (signal_processor(cpu,sigp_restart) == sigp_busy)
580 while (!cpu_online(cpu))
585 static unsigned int __initdata additional_cpus;
586 static unsigned int __initdata possible_cpus;
588 void __init smp_setup_cpu_possible_map(void)
590 unsigned int phy_cpus, pos_cpus, cpu;
592 phy_cpus = smp_count_cpus();
593 pos_cpus = min(phy_cpus + additional_cpus, (unsigned int) NR_CPUS);
596 pos_cpus = min(possible_cpus, (unsigned int) NR_CPUS);
598 for (cpu = 0; cpu < pos_cpus; cpu++)
599 cpu_set(cpu, cpu_possible_map);
601 phy_cpus = min(phy_cpus, pos_cpus);
603 for (cpu = 0; cpu < phy_cpus; cpu++)
604 cpu_set(cpu, cpu_present_map);
607 #ifdef CONFIG_HOTPLUG_CPU
609 static int __init setup_additional_cpus(char *s)
611 additional_cpus = simple_strtoul(s, NULL, 0);
614 early_param("additional_cpus", setup_additional_cpus);
616 static int __init setup_possible_cpus(char *s)
618 possible_cpus = simple_strtoul(s, NULL, 0);
621 early_param("possible_cpus", setup_possible_cpus);
627 struct ec_creg_mask_parms cr_parms;
628 int cpu = smp_processor_id();
630 spin_lock_irqsave(&smp_reserve_lock, flags);
631 if (smp_cpu_reserved[cpu] != 0) {
632 spin_unlock_irqrestore(&smp_reserve_lock, flags);
635 cpu_clear(cpu, cpu_online_map);
637 /* Disable pfault pseudo page faults on this cpu. */
640 memset(&cr_parms.orvals, 0, sizeof(cr_parms.orvals));
641 memset(&cr_parms.andvals, 0xff, sizeof(cr_parms.andvals));
643 /* disable all external interrupts */
644 cr_parms.orvals[0] = 0;
645 cr_parms.andvals[0] = ~(1<<15 | 1<<14 | 1<<13 | 1<<12 |
646 1<<11 | 1<<10 | 1<< 6 | 1<< 4);
647 /* disable all I/O interrupts */
648 cr_parms.orvals[6] = 0;
649 cr_parms.andvals[6] = ~(1<<31 | 1<<30 | 1<<29 | 1<<28 |
650 1<<27 | 1<<26 | 1<<25 | 1<<24);
651 /* disable most machine checks */
652 cr_parms.orvals[14] = 0;
653 cr_parms.andvals[14] = ~(1<<28 | 1<<27 | 1<<26 | 1<<25 | 1<<24);
655 smp_ctl_bit_callback(&cr_parms);
657 spin_unlock_irqrestore(&smp_reserve_lock, flags);
662 __cpu_die(unsigned int cpu)
664 /* Wait until target cpu is down */
665 while (!smp_cpu_not_running(cpu))
667 printk("Processor %d spun down\n", cpu);
674 signal_processor(smp_processor_id(), sigp_stop);
679 #endif /* CONFIG_HOTPLUG_CPU */
682 * Cycle through the processors and setup structures.
685 void __init smp_prepare_cpus(unsigned int max_cpus)
691 /* request the 0x1201 emergency signal external interrupt */
692 if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0)
693 panic("Couldn't request external interrupt 0x1201");
694 memset(lowcore_ptr,0,sizeof(lowcore_ptr));
696 * Initialize prefix pages and stacks for all possible cpus
698 print_cpu_info(&S390_lowcore.cpu_data);
700 for_each_possible_cpu(i) {
701 lowcore_ptr[i] = (struct _lowcore *)
702 __get_free_pages(GFP_KERNEL|GFP_DMA,
703 sizeof(void*) == 8 ? 1 : 0);
704 stack = __get_free_pages(GFP_KERNEL,ASYNC_ORDER);
705 if (lowcore_ptr[i] == NULL || stack == 0ULL)
706 panic("smp_boot_cpus failed to allocate memory\n");
708 *(lowcore_ptr[i]) = S390_lowcore;
709 lowcore_ptr[i]->async_stack = stack + (ASYNC_SIZE);
710 stack = __get_free_pages(GFP_KERNEL,0);
712 panic("smp_boot_cpus failed to allocate memory\n");
713 lowcore_ptr[i]->panic_stack = stack + (PAGE_SIZE);
715 if (MACHINE_HAS_IEEE) {
716 lowcore_ptr[i]->extended_save_area_addr =
717 (__u32) __get_free_pages(GFP_KERNEL,0);
718 if (lowcore_ptr[i]->extended_save_area_addr == 0)
719 panic("smp_boot_cpus failed to "
720 "allocate memory\n");
725 if (MACHINE_HAS_IEEE)
726 ctl_set_bit(14, 29); /* enable extended save area */
728 set_prefix((u32)(unsigned long) lowcore_ptr[smp_processor_id()]);
730 for_each_possible_cpu(cpu)
731 if (cpu != smp_processor_id())
732 smp_create_idle(cpu);
735 void __devinit smp_prepare_boot_cpu(void)
737 BUG_ON(smp_processor_id() != 0);
739 cpu_set(0, cpu_online_map);
740 S390_lowcore.percpu_offset = __per_cpu_offset[0];
741 current_set[0] = current;
744 void smp_cpus_done(unsigned int max_cpus)
746 cpu_present_map = cpu_possible_map;
750 * the frequency of the profiling timer can be changed
751 * by writing a multiplier value into /proc/profile.
753 * usually you want to run this on all CPUs ;)
755 int setup_profiling_timer(unsigned int multiplier)
760 static DEFINE_PER_CPU(struct cpu, cpu_devices);
762 static int __init topology_init(void)
767 for_each_possible_cpu(cpu) {
768 struct cpu *c = &per_cpu(cpu_devices, cpu);
771 ret = register_cpu(c, cpu);
773 printk(KERN_WARNING "topology_init: register_cpu %d "
774 "failed (%d)\n", cpu, ret);
779 subsys_initcall(topology_init);
781 EXPORT_SYMBOL(cpu_online_map);
782 EXPORT_SYMBOL(cpu_possible_map);
783 EXPORT_SYMBOL(lowcore_ptr);
784 EXPORT_SYMBOL(smp_ctl_set_bit);
785 EXPORT_SYMBOL(smp_ctl_clear_bit);
786 EXPORT_SYMBOL(smp_get_cpu);
787 EXPORT_SYMBOL(smp_put_cpu);