Merge branch 'linus' into x86/cleanups
[linux-2.6] / arch / s390 / kernel / smp.c
1 /*
2  *  arch/s390/kernel/smp.c
3  *
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)
8  *
9  *  based on other smp stuff by
10  *    (c) 1995 Alan Cox, CymruNET Ltd  <alan@cymru.net>
11  *    (c) 1998 Ingo Molnar
12  *
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.
21  */
22
23 #define KMSG_COMPONENT "cpu"
24 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
25
26 #include <linux/module.h>
27 #include <linux/init.h>
28 #include <linux/mm.h>
29 #include <linux/err.h>
30 #include <linux/spinlock.h>
31 #include <linux/kernel_stat.h>
32 #include <linux/delay.h>
33 #include <linux/cache.h>
34 #include <linux/interrupt.h>
35 #include <linux/cpu.h>
36 #include <linux/timex.h>
37 #include <linux/bootmem.h>
38 #include <asm/ipl.h>
39 #include <asm/setup.h>
40 #include <asm/sigp.h>
41 #include <asm/pgalloc.h>
42 #include <asm/irq.h>
43 #include <asm/s390_ext.h>
44 #include <asm/cpcmd.h>
45 #include <asm/tlbflush.h>
46 #include <asm/timer.h>
47 #include <asm/lowcore.h>
48 #include <asm/sclp.h>
49 #include <asm/cpu.h>
50 #include "entry.h"
51
52 /*
53  * An array with a pointer the lowcore of every CPU.
54  */
55 struct _lowcore *lowcore_ptr[NR_CPUS];
56 EXPORT_SYMBOL(lowcore_ptr);
57
58 cpumask_t cpu_online_map = CPU_MASK_NONE;
59 EXPORT_SYMBOL(cpu_online_map);
60
61 cpumask_t cpu_possible_map = CPU_MASK_ALL;
62 EXPORT_SYMBOL(cpu_possible_map);
63
64 static struct task_struct *current_set[NR_CPUS];
65
66 static u8 smp_cpu_type;
67 static int smp_use_sigp_detection;
68
69 enum s390_cpu_state {
70         CPU_STATE_STANDBY,
71         CPU_STATE_CONFIGURED,
72 };
73
74 DEFINE_MUTEX(smp_cpu_state_mutex);
75 int smp_cpu_polarization[NR_CPUS];
76 static int smp_cpu_state[NR_CPUS];
77 static int cpu_management;
78
79 static DEFINE_PER_CPU(struct cpu, cpu_devices);
80
81 static void smp_ext_bitcall(int, ec_bit_sig);
82
83 void smp_send_stop(void)
84 {
85         int cpu, rc;
86
87         /* Disable all interrupts/machine checks */
88         __load_psw_mask(psw_kernel_bits & ~PSW_MASK_MCHECK);
89
90         /* write magic number to zero page (absolute 0) */
91         lowcore_ptr[smp_processor_id()]->panic_magic = __PANIC_MAGIC;
92
93         /* stop all processors */
94         for_each_online_cpu(cpu) {
95                 if (cpu == smp_processor_id())
96                         continue;
97                 do {
98                         rc = signal_processor(cpu, sigp_stop);
99                 } while (rc == sigp_busy);
100
101                 while (!smp_cpu_not_running(cpu))
102                         cpu_relax();
103         }
104 }
105
106 /*
107  * This is the main routine where commands issued by other
108  * cpus are handled.
109  */
110
111 static void do_ext_call_interrupt(__u16 code)
112 {
113         unsigned long bits;
114
115         /*
116          * handle bit signal external calls
117          *
118          * For the ec_schedule signal we have to do nothing. All the work
119          * is done automatically when we return from the interrupt.
120          */
121         bits = xchg(&S390_lowcore.ext_call_fast, 0);
122
123         if (test_bit(ec_call_function, &bits))
124                 generic_smp_call_function_interrupt();
125
126         if (test_bit(ec_call_function_single, &bits))
127                 generic_smp_call_function_single_interrupt();
128 }
129
130 /*
131  * Send an external call sigp to another cpu and return without waiting
132  * for its completion.
133  */
134 static void smp_ext_bitcall(int cpu, ec_bit_sig sig)
135 {
136         /*
137          * Set signaling bit in lowcore of target cpu and kick it
138          */
139         set_bit(sig, (unsigned long *) &lowcore_ptr[cpu]->ext_call_fast);
140         while (signal_processor(cpu, sigp_emergency_signal) == sigp_busy)
141                 udelay(10);
142 }
143
144 void arch_send_call_function_ipi(cpumask_t mask)
145 {
146         int cpu;
147
148         for_each_cpu_mask(cpu, mask)
149                 smp_ext_bitcall(cpu, ec_call_function);
150 }
151
152 void arch_send_call_function_single_ipi(int cpu)
153 {
154         smp_ext_bitcall(cpu, ec_call_function_single);
155 }
156
157 #ifndef CONFIG_64BIT
158 /*
159  * this function sends a 'purge tlb' signal to another CPU.
160  */
161 static void smp_ptlb_callback(void *info)
162 {
163         __tlb_flush_local();
164 }
165
166 void smp_ptlb_all(void)
167 {
168         on_each_cpu(smp_ptlb_callback, NULL, 1);
169 }
170 EXPORT_SYMBOL(smp_ptlb_all);
171 #endif /* ! CONFIG_64BIT */
172
173 /*
174  * this function sends a 'reschedule' IPI to another CPU.
175  * it goes straight through and wastes no time serializing
176  * anything. Worst case is that we lose a reschedule ...
177  */
178 void smp_send_reschedule(int cpu)
179 {
180         smp_ext_bitcall(cpu, ec_schedule);
181 }
182
183 /*
184  * parameter area for the set/clear control bit callbacks
185  */
186 struct ec_creg_mask_parms {
187         unsigned long orvals[16];
188         unsigned long andvals[16];
189 };
190
191 /*
192  * callback for setting/clearing control bits
193  */
194 static void smp_ctl_bit_callback(void *info)
195 {
196         struct ec_creg_mask_parms *pp = info;
197         unsigned long cregs[16];
198         int i;
199
200         __ctl_store(cregs, 0, 15);
201         for (i = 0; i <= 15; i++)
202                 cregs[i] = (cregs[i] & pp->andvals[i]) | pp->orvals[i];
203         __ctl_load(cregs, 0, 15);
204 }
205
206 /*
207  * Set a bit in a control register of all cpus
208  */
209 void smp_ctl_set_bit(int cr, int bit)
210 {
211         struct ec_creg_mask_parms parms;
212
213         memset(&parms.orvals, 0, sizeof(parms.orvals));
214         memset(&parms.andvals, 0xff, sizeof(parms.andvals));
215         parms.orvals[cr] = 1 << bit;
216         on_each_cpu(smp_ctl_bit_callback, &parms, 1);
217 }
218 EXPORT_SYMBOL(smp_ctl_set_bit);
219
220 /*
221  * Clear a bit in a control register of all cpus
222  */
223 void smp_ctl_clear_bit(int cr, int bit)
224 {
225         struct ec_creg_mask_parms parms;
226
227         memset(&parms.orvals, 0, sizeof(parms.orvals));
228         memset(&parms.andvals, 0xff, sizeof(parms.andvals));
229         parms.andvals[cr] = ~(1L << bit);
230         on_each_cpu(smp_ctl_bit_callback, &parms, 1);
231 }
232 EXPORT_SYMBOL(smp_ctl_clear_bit);
233
234 /*
235  * In early ipl state a temp. logically cpu number is needed, so the sigp
236  * functions can be used to sense other cpus. Since NR_CPUS is >= 2 on
237  * CONFIG_SMP and the ipl cpu is logical cpu 0, it must be 1.
238  */
239 #define CPU_INIT_NO     1
240
241 #if defined(CONFIG_ZFCPDUMP) || defined(CONFIG_ZFCPDUMP_MODULE)
242
243 /*
244  * zfcpdump_prefix_array holds prefix registers for the following scenario:
245  * 64 bit zfcpdump kernel and 31 bit kernel which is to be dumped. We have to
246  * save its prefix registers, since they get lost, when switching from 31 bit
247  * to 64 bit.
248  */
249 unsigned int zfcpdump_prefix_array[NR_CPUS + 1] \
250         __attribute__((__section__(".data")));
251
252 static void __init smp_get_save_area(unsigned int cpu, unsigned int phy_cpu)
253 {
254         if (ipl_info.type != IPL_TYPE_FCP_DUMP)
255                 return;
256         if (cpu >= NR_CPUS) {
257                 pr_warning("CPU %i exceeds the maximum %i and is excluded from "
258                            "the dump\n", cpu, NR_CPUS - 1);
259                 return;
260         }
261         zfcpdump_save_areas[cpu] = kmalloc(sizeof(union save_area), GFP_KERNEL);
262         __cpu_logical_map[CPU_INIT_NO] = (__u16) phy_cpu;
263         while (signal_processor(CPU_INIT_NO, sigp_stop_and_store_status) ==
264                sigp_busy)
265                 cpu_relax();
266         memcpy(zfcpdump_save_areas[cpu],
267                (void *)(unsigned long) store_prefix() + SAVE_AREA_BASE,
268                SAVE_AREA_SIZE);
269 #ifdef CONFIG_64BIT
270         /* copy original prefix register */
271         zfcpdump_save_areas[cpu]->s390x.pref_reg = zfcpdump_prefix_array[cpu];
272 #endif
273 }
274
275 union save_area *zfcpdump_save_areas[NR_CPUS + 1];
276 EXPORT_SYMBOL_GPL(zfcpdump_save_areas);
277
278 #else
279
280 static inline void smp_get_save_area(unsigned int cpu, unsigned int phy_cpu) { }
281
282 #endif /* CONFIG_ZFCPDUMP || CONFIG_ZFCPDUMP_MODULE */
283
284 static int cpu_stopped(int cpu)
285 {
286         __u32 status;
287
288         /* Check for stopped state */
289         if (signal_processor_ps(&status, 0, cpu, sigp_sense) ==
290             sigp_status_stored) {
291                 if (status & 0x40)
292                         return 1;
293         }
294         return 0;
295 }
296
297 static int cpu_known(int cpu_id)
298 {
299         int cpu;
300
301         for_each_present_cpu(cpu) {
302                 if (__cpu_logical_map[cpu] == cpu_id)
303                         return 1;
304         }
305         return 0;
306 }
307
308 static int smp_rescan_cpus_sigp(cpumask_t avail)
309 {
310         int cpu_id, logical_cpu;
311
312         logical_cpu = first_cpu(avail);
313         if (logical_cpu == NR_CPUS)
314                 return 0;
315         for (cpu_id = 0; cpu_id <= 65535; cpu_id++) {
316                 if (cpu_known(cpu_id))
317                         continue;
318                 __cpu_logical_map[logical_cpu] = cpu_id;
319                 smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN;
320                 if (!cpu_stopped(logical_cpu))
321                         continue;
322                 cpu_set(logical_cpu, cpu_present_map);
323                 smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
324                 logical_cpu = next_cpu(logical_cpu, avail);
325                 if (logical_cpu == NR_CPUS)
326                         break;
327         }
328         return 0;
329 }
330
331 static int smp_rescan_cpus_sclp(cpumask_t avail)
332 {
333         struct sclp_cpu_info *info;
334         int cpu_id, logical_cpu, cpu;
335         int rc;
336
337         logical_cpu = first_cpu(avail);
338         if (logical_cpu == NR_CPUS)
339                 return 0;
340         info = kmalloc(sizeof(*info), GFP_KERNEL);
341         if (!info)
342                 return -ENOMEM;
343         rc = sclp_get_cpu_info(info);
344         if (rc)
345                 goto out;
346         for (cpu = 0; cpu < info->combined; cpu++) {
347                 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
348                         continue;
349                 cpu_id = info->cpu[cpu].address;
350                 if (cpu_known(cpu_id))
351                         continue;
352                 __cpu_logical_map[logical_cpu] = cpu_id;
353                 smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN;
354                 cpu_set(logical_cpu, cpu_present_map);
355                 if (cpu >= info->configured)
356                         smp_cpu_state[logical_cpu] = CPU_STATE_STANDBY;
357                 else
358                         smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
359                 logical_cpu = next_cpu(logical_cpu, avail);
360                 if (logical_cpu == NR_CPUS)
361                         break;
362         }
363 out:
364         kfree(info);
365         return rc;
366 }
367
368 static int __smp_rescan_cpus(void)
369 {
370         cpumask_t avail;
371
372         cpus_xor(avail, cpu_possible_map, cpu_present_map);
373         if (smp_use_sigp_detection)
374                 return smp_rescan_cpus_sigp(avail);
375         else
376                 return smp_rescan_cpus_sclp(avail);
377 }
378
379 static void __init smp_detect_cpus(void)
380 {
381         unsigned int cpu, c_cpus, s_cpus;
382         struct sclp_cpu_info *info;
383         u16 boot_cpu_addr, cpu_addr;
384
385         c_cpus = 1;
386         s_cpus = 0;
387         boot_cpu_addr = S390_lowcore.cpu_data.cpu_addr;
388         info = kmalloc(sizeof(*info), GFP_KERNEL);
389         if (!info)
390                 panic("smp_detect_cpus failed to allocate memory\n");
391         /* Use sigp detection algorithm if sclp doesn't work. */
392         if (sclp_get_cpu_info(info)) {
393                 smp_use_sigp_detection = 1;
394                 for (cpu = 0; cpu <= 65535; cpu++) {
395                         if (cpu == boot_cpu_addr)
396                                 continue;
397                         __cpu_logical_map[CPU_INIT_NO] = cpu;
398                         if (!cpu_stopped(CPU_INIT_NO))
399                                 continue;
400                         smp_get_save_area(c_cpus, cpu);
401                         c_cpus++;
402                 }
403                 goto out;
404         }
405
406         if (info->has_cpu_type) {
407                 for (cpu = 0; cpu < info->combined; cpu++) {
408                         if (info->cpu[cpu].address == boot_cpu_addr) {
409                                 smp_cpu_type = info->cpu[cpu].type;
410                                 break;
411                         }
412                 }
413         }
414
415         for (cpu = 0; cpu < info->combined; cpu++) {
416                 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
417                         continue;
418                 cpu_addr = info->cpu[cpu].address;
419                 if (cpu_addr == boot_cpu_addr)
420                         continue;
421                 __cpu_logical_map[CPU_INIT_NO] = cpu_addr;
422                 if (!cpu_stopped(CPU_INIT_NO)) {
423                         s_cpus++;
424                         continue;
425                 }
426                 smp_get_save_area(c_cpus, cpu_addr);
427                 c_cpus++;
428         }
429 out:
430         kfree(info);
431         pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
432         get_online_cpus();
433         __smp_rescan_cpus();
434         put_online_cpus();
435 }
436
437 /*
438  *      Activate a secondary processor.
439  */
440 int __cpuinit start_secondary(void *cpuvoid)
441 {
442         /* Setup the cpu */
443         cpu_init();
444         preempt_disable();
445         /* Enable TOD clock interrupts on the secondary cpu. */
446         init_cpu_timer();
447         /* Enable cpu timer interrupts on the secondary cpu. */
448         init_cpu_vtimer();
449         /* Enable pfault pseudo page faults on this cpu. */
450         pfault_init();
451
452         /* call cpu notifiers */
453         notify_cpu_starting(smp_processor_id());
454         /* Mark this cpu as online */
455         ipi_call_lock();
456         cpu_set(smp_processor_id(), cpu_online_map);
457         ipi_call_unlock();
458         /* Switch on interrupts */
459         local_irq_enable();
460         /* Print info about this processor */
461         print_cpu_info(&S390_lowcore.cpu_data);
462         /* cpu_idle will call schedule for us */
463         cpu_idle();
464         return 0;
465 }
466
467 static void __init smp_create_idle(unsigned int cpu)
468 {
469         struct task_struct *p;
470
471         /*
472          *  don't care about the psw and regs settings since we'll never
473          *  reschedule the forked task.
474          */
475         p = fork_idle(cpu);
476         if (IS_ERR(p))
477                 panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p));
478         current_set[cpu] = p;
479 }
480
481 static int __cpuinit smp_alloc_lowcore(int cpu)
482 {
483         unsigned long async_stack, panic_stack;
484         struct _lowcore *lowcore;
485         int lc_order;
486
487         lc_order = sizeof(long) == 8 ? 1 : 0;
488         lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, lc_order);
489         if (!lowcore)
490                 return -ENOMEM;
491         async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
492         panic_stack = __get_free_page(GFP_KERNEL);
493         if (!panic_stack || !async_stack)
494                 goto out;
495         memcpy(lowcore, &S390_lowcore, 512);
496         memset((char *)lowcore + 512, 0, sizeof(*lowcore) - 512);
497         lowcore->async_stack = async_stack + ASYNC_SIZE;
498         lowcore->panic_stack = panic_stack + PAGE_SIZE;
499
500 #ifndef CONFIG_64BIT
501         if (MACHINE_HAS_IEEE) {
502                 unsigned long save_area;
503
504                 save_area = get_zeroed_page(GFP_KERNEL);
505                 if (!save_area)
506                         goto out;
507                 lowcore->extended_save_area_addr = (u32) save_area;
508         }
509 #endif
510         lowcore_ptr[cpu] = lowcore;
511         return 0;
512
513 out:
514         free_page(panic_stack);
515         free_pages(async_stack, ASYNC_ORDER);
516         free_pages((unsigned long) lowcore, lc_order);
517         return -ENOMEM;
518 }
519
520 #ifdef CONFIG_HOTPLUG_CPU
521 static void smp_free_lowcore(int cpu)
522 {
523         struct _lowcore *lowcore;
524         int lc_order;
525
526         lc_order = sizeof(long) == 8 ? 1 : 0;
527         lowcore = lowcore_ptr[cpu];
528 #ifndef CONFIG_64BIT
529         if (MACHINE_HAS_IEEE)
530                 free_page((unsigned long) lowcore->extended_save_area_addr);
531 #endif
532         free_page(lowcore->panic_stack - PAGE_SIZE);
533         free_pages(lowcore->async_stack - ASYNC_SIZE, ASYNC_ORDER);
534         free_pages((unsigned long) lowcore, lc_order);
535         lowcore_ptr[cpu] = NULL;
536 }
537 #endif /* CONFIG_HOTPLUG_CPU */
538
539 /* Upping and downing of CPUs */
540 int __cpuinit __cpu_up(unsigned int cpu)
541 {
542         struct task_struct *idle;
543         struct _lowcore *cpu_lowcore;
544         struct stack_frame *sf;
545         sigp_ccode ccode;
546
547         if (smp_cpu_state[cpu] != CPU_STATE_CONFIGURED)
548                 return -EIO;
549         if (smp_alloc_lowcore(cpu))
550                 return -ENOMEM;
551
552         ccode = signal_processor_p((__u32)(unsigned long)(lowcore_ptr[cpu]),
553                                    cpu, sigp_set_prefix);
554         if (ccode)
555                 return -EIO;
556
557         idle = current_set[cpu];
558         cpu_lowcore = lowcore_ptr[cpu];
559         cpu_lowcore->kernel_stack = (unsigned long)
560                 task_stack_page(idle) + THREAD_SIZE;
561         cpu_lowcore->thread_info = (unsigned long) task_thread_info(idle);
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, 15);
569         asm volatile(
570                 "       stam    0,15,0(%0)"
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;
575         cpu_lowcore->kernel_asce = S390_lowcore.kernel_asce;
576         cpu_lowcore->ipl_device = S390_lowcore.ipl_device;
577         eieio();
578
579         while (signal_processor(cpu, sigp_restart) == sigp_busy)
580                 udelay(10);
581
582         while (!cpu_online(cpu))
583                 cpu_relax();
584         return 0;
585 }
586
587 static int __init setup_possible_cpus(char *s)
588 {
589         int pcpus, cpu;
590
591         pcpus = simple_strtoul(s, NULL, 0);
592         cpu_possible_map = cpumask_of_cpu(0);
593         for (cpu = 1; cpu < pcpus && cpu < NR_CPUS; cpu++)
594                 cpu_set(cpu, cpu_possible_map);
595         return 0;
596 }
597 early_param("possible_cpus", setup_possible_cpus);
598
599 #ifdef CONFIG_HOTPLUG_CPU
600
601 int __cpu_disable(void)
602 {
603         struct ec_creg_mask_parms cr_parms;
604         int cpu = smp_processor_id();
605
606         cpu_clear(cpu, cpu_online_map);
607
608         /* Disable pfault pseudo page faults on this cpu. */
609         pfault_fini();
610
611         memset(&cr_parms.orvals, 0, sizeof(cr_parms.orvals));
612         memset(&cr_parms.andvals, 0xff, sizeof(cr_parms.andvals));
613
614         /* disable all external interrupts */
615         cr_parms.orvals[0] = 0;
616         cr_parms.andvals[0] = ~(1 << 15 | 1 << 14 | 1 << 13 | 1 << 12 |
617                                 1 << 11 | 1 << 10 | 1 <<  6 | 1 <<  4);
618         /* disable all I/O interrupts */
619         cr_parms.orvals[6] = 0;
620         cr_parms.andvals[6] = ~(1 << 31 | 1 << 30 | 1 << 29 | 1 << 28 |
621                                 1 << 27 | 1 << 26 | 1 << 25 | 1 << 24);
622         /* disable most machine checks */
623         cr_parms.orvals[14] = 0;
624         cr_parms.andvals[14] = ~(1 << 28 | 1 << 27 | 1 << 26 |
625                                  1 << 25 | 1 << 24);
626
627         smp_ctl_bit_callback(&cr_parms);
628
629         return 0;
630 }
631
632 void __cpu_die(unsigned int cpu)
633 {
634         /* Wait until target cpu is down */
635         while (!smp_cpu_not_running(cpu))
636                 cpu_relax();
637         smp_free_lowcore(cpu);
638         pr_info("Processor %d stopped\n", cpu);
639 }
640
641 void cpu_die(void)
642 {
643         idle_task_exit();
644         signal_processor(smp_processor_id(), sigp_stop);
645         BUG();
646         for (;;);
647 }
648
649 #endif /* CONFIG_HOTPLUG_CPU */
650
651 void __init smp_prepare_cpus(unsigned int max_cpus)
652 {
653 #ifndef CONFIG_64BIT
654         unsigned long save_area = 0;
655 #endif
656         unsigned long async_stack, panic_stack;
657         struct _lowcore *lowcore;
658         unsigned int cpu;
659         int lc_order;
660
661         smp_detect_cpus();
662
663         /* request the 0x1201 emergency signal external interrupt */
664         if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0)
665                 panic("Couldn't request external interrupt 0x1201");
666         print_cpu_info(&S390_lowcore.cpu_data);
667
668         /* Reallocate current lowcore, but keep its contents. */
669         lc_order = sizeof(long) == 8 ? 1 : 0;
670         lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, lc_order);
671         panic_stack = __get_free_page(GFP_KERNEL);
672         async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
673 #ifndef CONFIG_64BIT
674         if (MACHINE_HAS_IEEE)
675                 save_area = get_zeroed_page(GFP_KERNEL);
676 #endif
677         local_irq_disable();
678         local_mcck_disable();
679         lowcore_ptr[smp_processor_id()] = lowcore;
680         *lowcore = S390_lowcore;
681         lowcore->panic_stack = panic_stack + PAGE_SIZE;
682         lowcore->async_stack = async_stack + ASYNC_SIZE;
683 #ifndef CONFIG_64BIT
684         if (MACHINE_HAS_IEEE)
685                 lowcore->extended_save_area_addr = (u32) save_area;
686 #endif
687         set_prefix((u32)(unsigned long) lowcore);
688         local_mcck_enable();
689         local_irq_enable();
690         for_each_possible_cpu(cpu)
691                 if (cpu != smp_processor_id())
692                         smp_create_idle(cpu);
693 }
694
695 void __init smp_prepare_boot_cpu(void)
696 {
697         BUG_ON(smp_processor_id() != 0);
698
699         current_thread_info()->cpu = 0;
700         cpu_set(0, cpu_present_map);
701         cpu_set(0, cpu_online_map);
702         S390_lowcore.percpu_offset = __per_cpu_offset[0];
703         current_set[0] = current;
704         smp_cpu_state[0] = CPU_STATE_CONFIGURED;
705         smp_cpu_polarization[0] = POLARIZATION_UNKNWN;
706 }
707
708 void __init smp_cpus_done(unsigned int max_cpus)
709 {
710 }
711
712 /*
713  * the frequency of the profiling timer can be changed
714  * by writing a multiplier value into /proc/profile.
715  *
716  * usually you want to run this on all CPUs ;)
717  */
718 int setup_profiling_timer(unsigned int multiplier)
719 {
720         return 0;
721 }
722
723 #ifdef CONFIG_HOTPLUG_CPU
724 static ssize_t cpu_configure_show(struct sys_device *dev,
725                                 struct sysdev_attribute *attr, char *buf)
726 {
727         ssize_t count;
728
729         mutex_lock(&smp_cpu_state_mutex);
730         count = sprintf(buf, "%d\n", smp_cpu_state[dev->id]);
731         mutex_unlock(&smp_cpu_state_mutex);
732         return count;
733 }
734
735 static ssize_t cpu_configure_store(struct sys_device *dev,
736                                   struct sysdev_attribute *attr,
737                                   const char *buf, size_t count)
738 {
739         int cpu = dev->id;
740         int val, rc;
741         char delim;
742
743         if (sscanf(buf, "%d %c", &val, &delim) != 1)
744                 return -EINVAL;
745         if (val != 0 && val != 1)
746                 return -EINVAL;
747
748         get_online_cpus();
749         mutex_lock(&smp_cpu_state_mutex);
750         rc = -EBUSY;
751         if (cpu_online(cpu))
752                 goto out;
753         rc = 0;
754         switch (val) {
755         case 0:
756                 if (smp_cpu_state[cpu] == CPU_STATE_CONFIGURED) {
757                         rc = sclp_cpu_deconfigure(__cpu_logical_map[cpu]);
758                         if (!rc) {
759                                 smp_cpu_state[cpu] = CPU_STATE_STANDBY;
760                                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
761                         }
762                 }
763                 break;
764         case 1:
765                 if (smp_cpu_state[cpu] == CPU_STATE_STANDBY) {
766                         rc = sclp_cpu_configure(__cpu_logical_map[cpu]);
767                         if (!rc) {
768                                 smp_cpu_state[cpu] = CPU_STATE_CONFIGURED;
769                                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
770                         }
771                 }
772                 break;
773         default:
774                 break;
775         }
776 out:
777         mutex_unlock(&smp_cpu_state_mutex);
778         put_online_cpus();
779         return rc ? rc : count;
780 }
781 static SYSDEV_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
782 #endif /* CONFIG_HOTPLUG_CPU */
783
784 static ssize_t cpu_polarization_show(struct sys_device *dev,
785                                      struct sysdev_attribute *attr, char *buf)
786 {
787         int cpu = dev->id;
788         ssize_t count;
789
790         mutex_lock(&smp_cpu_state_mutex);
791         switch (smp_cpu_polarization[cpu]) {
792         case POLARIZATION_HRZ:
793                 count = sprintf(buf, "horizontal\n");
794                 break;
795         case POLARIZATION_VL:
796                 count = sprintf(buf, "vertical:low\n");
797                 break;
798         case POLARIZATION_VM:
799                 count = sprintf(buf, "vertical:medium\n");
800                 break;
801         case POLARIZATION_VH:
802                 count = sprintf(buf, "vertical:high\n");
803                 break;
804         default:
805                 count = sprintf(buf, "unknown\n");
806                 break;
807         }
808         mutex_unlock(&smp_cpu_state_mutex);
809         return count;
810 }
811 static SYSDEV_ATTR(polarization, 0444, cpu_polarization_show, NULL);
812
813 static ssize_t show_cpu_address(struct sys_device *dev,
814                                 struct sysdev_attribute *attr, char *buf)
815 {
816         return sprintf(buf, "%d\n", __cpu_logical_map[dev->id]);
817 }
818 static SYSDEV_ATTR(address, 0444, show_cpu_address, NULL);
819
820
821 static struct attribute *cpu_common_attrs[] = {
822 #ifdef CONFIG_HOTPLUG_CPU
823         &attr_configure.attr,
824 #endif
825         &attr_address.attr,
826         &attr_polarization.attr,
827         NULL,
828 };
829
830 static struct attribute_group cpu_common_attr_group = {
831         .attrs = cpu_common_attrs,
832 };
833
834 static ssize_t show_capability(struct sys_device *dev,
835                                 struct sysdev_attribute *attr, char *buf)
836 {
837         unsigned int capability;
838         int rc;
839
840         rc = get_cpu_capability(&capability);
841         if (rc)
842                 return rc;
843         return sprintf(buf, "%u\n", capability);
844 }
845 static SYSDEV_ATTR(capability, 0444, show_capability, NULL);
846
847 static ssize_t show_idle_count(struct sys_device *dev,
848                                 struct sysdev_attribute *attr, char *buf)
849 {
850         struct s390_idle_data *idle;
851         unsigned long long idle_count;
852
853         idle = &per_cpu(s390_idle, dev->id);
854         spin_lock_irq(&idle->lock);
855         idle_count = idle->idle_count;
856         spin_unlock_irq(&idle->lock);
857         return sprintf(buf, "%llu\n", idle_count);
858 }
859 static SYSDEV_ATTR(idle_count, 0444, show_idle_count, NULL);
860
861 static ssize_t show_idle_time(struct sys_device *dev,
862                                 struct sysdev_attribute *attr, char *buf)
863 {
864         struct s390_idle_data *idle;
865         unsigned long long new_time;
866
867         idle = &per_cpu(s390_idle, dev->id);
868         spin_lock_irq(&idle->lock);
869         if (idle->in_idle) {
870                 new_time = get_clock();
871                 idle->idle_time += new_time - idle->idle_enter;
872                 idle->idle_enter = new_time;
873         }
874         new_time = idle->idle_time;
875         spin_unlock_irq(&idle->lock);
876         return sprintf(buf, "%llu\n", new_time >> 12);
877 }
878 static SYSDEV_ATTR(idle_time_us, 0444, show_idle_time, NULL);
879
880 static struct attribute *cpu_online_attrs[] = {
881         &attr_capability.attr,
882         &attr_idle_count.attr,
883         &attr_idle_time_us.attr,
884         NULL,
885 };
886
887 static struct attribute_group cpu_online_attr_group = {
888         .attrs = cpu_online_attrs,
889 };
890
891 static int __cpuinit smp_cpu_notify(struct notifier_block *self,
892                                     unsigned long action, void *hcpu)
893 {
894         unsigned int cpu = (unsigned int)(long)hcpu;
895         struct cpu *c = &per_cpu(cpu_devices, cpu);
896         struct sys_device *s = &c->sysdev;
897         struct s390_idle_data *idle;
898
899         switch (action) {
900         case CPU_ONLINE:
901         case CPU_ONLINE_FROZEN:
902                 idle = &per_cpu(s390_idle, cpu);
903                 spin_lock_irq(&idle->lock);
904                 idle->idle_enter = 0;
905                 idle->idle_time = 0;
906                 idle->idle_count = 0;
907                 spin_unlock_irq(&idle->lock);
908                 if (sysfs_create_group(&s->kobj, &cpu_online_attr_group))
909                         return NOTIFY_BAD;
910                 break;
911         case CPU_DEAD:
912         case CPU_DEAD_FROZEN:
913                 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
914                 break;
915         }
916         return NOTIFY_OK;
917 }
918
919 static struct notifier_block __cpuinitdata smp_cpu_nb = {
920         .notifier_call = smp_cpu_notify,
921 };
922
923 static int __devinit smp_add_present_cpu(int cpu)
924 {
925         struct cpu *c = &per_cpu(cpu_devices, cpu);
926         struct sys_device *s = &c->sysdev;
927         int rc;
928
929         c->hotpluggable = 1;
930         rc = register_cpu(c, cpu);
931         if (rc)
932                 goto out;
933         rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
934         if (rc)
935                 goto out_cpu;
936         if (!cpu_online(cpu))
937                 goto out;
938         rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
939         if (!rc)
940                 return 0;
941         sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
942 out_cpu:
943 #ifdef CONFIG_HOTPLUG_CPU
944         unregister_cpu(c);
945 #endif
946 out:
947         return rc;
948 }
949
950 #ifdef CONFIG_HOTPLUG_CPU
951
952 int __ref smp_rescan_cpus(void)
953 {
954         cpumask_t newcpus;
955         int cpu;
956         int rc;
957
958         get_online_cpus();
959         mutex_lock(&smp_cpu_state_mutex);
960         newcpus = cpu_present_map;
961         rc = __smp_rescan_cpus();
962         if (rc)
963                 goto out;
964         cpus_andnot(newcpus, cpu_present_map, newcpus);
965         for_each_cpu_mask(cpu, newcpus) {
966                 rc = smp_add_present_cpu(cpu);
967                 if (rc)
968                         cpu_clear(cpu, cpu_present_map);
969         }
970         rc = 0;
971 out:
972         mutex_unlock(&smp_cpu_state_mutex);
973         put_online_cpus();
974         if (!cpus_empty(newcpus))
975                 topology_schedule_update();
976         return rc;
977 }
978
979 static ssize_t __ref rescan_store(struct sysdev_class *class, const char *buf,
980                                   size_t count)
981 {
982         int rc;
983
984         rc = smp_rescan_cpus();
985         return rc ? rc : count;
986 }
987 static SYSDEV_CLASS_ATTR(rescan, 0200, NULL, rescan_store);
988 #endif /* CONFIG_HOTPLUG_CPU */
989
990 static ssize_t dispatching_show(struct sysdev_class *class, char *buf)
991 {
992         ssize_t count;
993
994         mutex_lock(&smp_cpu_state_mutex);
995         count = sprintf(buf, "%d\n", cpu_management);
996         mutex_unlock(&smp_cpu_state_mutex);
997         return count;
998 }
999
1000 static ssize_t dispatching_store(struct sysdev_class *dev, const char *buf,
1001                                  size_t count)
1002 {
1003         int val, rc;
1004         char delim;
1005
1006         if (sscanf(buf, "%d %c", &val, &delim) != 1)
1007                 return -EINVAL;
1008         if (val != 0 && val != 1)
1009                 return -EINVAL;
1010         rc = 0;
1011         get_online_cpus();
1012         mutex_lock(&smp_cpu_state_mutex);
1013         if (cpu_management == val)
1014                 goto out;
1015         rc = topology_set_cpu_management(val);
1016         if (!rc)
1017                 cpu_management = val;
1018 out:
1019         mutex_unlock(&smp_cpu_state_mutex);
1020         put_online_cpus();
1021         return rc ? rc : count;
1022 }
1023 static SYSDEV_CLASS_ATTR(dispatching, 0644, dispatching_show,
1024                          dispatching_store);
1025
1026 static int __init topology_init(void)
1027 {
1028         int cpu;
1029         int rc;
1030
1031         register_cpu_notifier(&smp_cpu_nb);
1032
1033 #ifdef CONFIG_HOTPLUG_CPU
1034         rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_rescan);
1035         if (rc)
1036                 return rc;
1037 #endif
1038         rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_dispatching);
1039         if (rc)
1040                 return rc;
1041         for_each_present_cpu(cpu) {
1042                 rc = smp_add_present_cpu(cpu);
1043                 if (rc)
1044                         return rc;
1045         }
1046         return 0;
1047 }
1048 subsys_initcall(topology_init);