3ed5c7a83c6c477e242ab411de06f7af35121f7a
[linux-2.6.git] / 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 static struct task_struct *current_set[NR_CPUS];
59
60 static u8 smp_cpu_type;
61 static int smp_use_sigp_detection;
62
63 enum s390_cpu_state {
64         CPU_STATE_STANDBY,
65         CPU_STATE_CONFIGURED,
66 };
67
68 DEFINE_MUTEX(smp_cpu_state_mutex);
69 int smp_cpu_polarization[NR_CPUS];
70 static int smp_cpu_state[NR_CPUS];
71 static int cpu_management;
72
73 static DEFINE_PER_CPU(struct cpu, cpu_devices);
74
75 static void smp_ext_bitcall(int, ec_bit_sig);
76
77 void smp_send_stop(void)
78 {
79         int cpu, rc;
80
81         /* Disable all interrupts/machine checks */
82         __load_psw_mask(psw_kernel_bits & ~PSW_MASK_MCHECK);
83
84         /* write magic number to zero page (absolute 0) */
85         lowcore_ptr[smp_processor_id()]->panic_magic = __PANIC_MAGIC;
86
87         /* stop all processors */
88         for_each_online_cpu(cpu) {
89                 if (cpu == smp_processor_id())
90                         continue;
91                 do {
92                         rc = signal_processor(cpu, sigp_stop);
93                 } while (rc == sigp_busy);
94
95                 while (!smp_cpu_not_running(cpu))
96                         cpu_relax();
97         }
98 }
99
100 /*
101  * This is the main routine where commands issued by other
102  * cpus are handled.
103  */
104
105 static void do_ext_call_interrupt(__u16 code)
106 {
107         unsigned long bits;
108
109         /*
110          * handle bit signal external calls
111          *
112          * For the ec_schedule signal we have to do nothing. All the work
113          * is done automatically when we return from the interrupt.
114          */
115         bits = xchg(&S390_lowcore.ext_call_fast, 0);
116
117         if (test_bit(ec_call_function, &bits))
118                 generic_smp_call_function_interrupt();
119
120         if (test_bit(ec_call_function_single, &bits))
121                 generic_smp_call_function_single_interrupt();
122 }
123
124 /*
125  * Send an external call sigp to another cpu and return without waiting
126  * for its completion.
127  */
128 static void smp_ext_bitcall(int cpu, ec_bit_sig sig)
129 {
130         /*
131          * Set signaling bit in lowcore of target cpu and kick it
132          */
133         set_bit(sig, (unsigned long *) &lowcore_ptr[cpu]->ext_call_fast);
134         while (signal_processor(cpu, sigp_emergency_signal) == sigp_busy)
135                 udelay(10);
136 }
137
138 void arch_send_call_function_ipi(cpumask_t mask)
139 {
140         int cpu;
141
142         for_each_cpu_mask(cpu, mask)
143                 smp_ext_bitcall(cpu, ec_call_function);
144 }
145
146 void arch_send_call_function_single_ipi(int cpu)
147 {
148         smp_ext_bitcall(cpu, ec_call_function_single);
149 }
150
151 #ifndef CONFIG_64BIT
152 /*
153  * this function sends a 'purge tlb' signal to another CPU.
154  */
155 static void smp_ptlb_callback(void *info)
156 {
157         __tlb_flush_local();
158 }
159
160 void smp_ptlb_all(void)
161 {
162         on_each_cpu(smp_ptlb_callback, NULL, 1);
163 }
164 EXPORT_SYMBOL(smp_ptlb_all);
165 #endif /* ! CONFIG_64BIT */
166
167 /*
168  * this function sends a 'reschedule' IPI to another CPU.
169  * it goes straight through and wastes no time serializing
170  * anything. Worst case is that we lose a reschedule ...
171  */
172 void smp_send_reschedule(int cpu)
173 {
174         smp_ext_bitcall(cpu, ec_schedule);
175 }
176
177 /*
178  * parameter area for the set/clear control bit callbacks
179  */
180 struct ec_creg_mask_parms {
181         unsigned long orvals[16];
182         unsigned long andvals[16];
183 };
184
185 /*
186  * callback for setting/clearing control bits
187  */
188 static void smp_ctl_bit_callback(void *info)
189 {
190         struct ec_creg_mask_parms *pp = info;
191         unsigned long cregs[16];
192         int i;
193
194         __ctl_store(cregs, 0, 15);
195         for (i = 0; i <= 15; i++)
196                 cregs[i] = (cregs[i] & pp->andvals[i]) | pp->orvals[i];
197         __ctl_load(cregs, 0, 15);
198 }
199
200 /*
201  * Set a bit in a control register of all cpus
202  */
203 void smp_ctl_set_bit(int cr, int bit)
204 {
205         struct ec_creg_mask_parms parms;
206
207         memset(&parms.orvals, 0, sizeof(parms.orvals));
208         memset(&parms.andvals, 0xff, sizeof(parms.andvals));
209         parms.orvals[cr] = 1 << bit;
210         on_each_cpu(smp_ctl_bit_callback, &parms, 1);
211 }
212 EXPORT_SYMBOL(smp_ctl_set_bit);
213
214 /*
215  * Clear a bit in a control register of all cpus
216  */
217 void smp_ctl_clear_bit(int cr, int bit)
218 {
219         struct ec_creg_mask_parms parms;
220
221         memset(&parms.orvals, 0, sizeof(parms.orvals));
222         memset(&parms.andvals, 0xff, sizeof(parms.andvals));
223         parms.andvals[cr] = ~(1L << bit);
224         on_each_cpu(smp_ctl_bit_callback, &parms, 1);
225 }
226 EXPORT_SYMBOL(smp_ctl_clear_bit);
227
228 /*
229  * In early ipl state a temp. logically cpu number is needed, so the sigp
230  * functions can be used to sense other cpus. Since NR_CPUS is >= 2 on
231  * CONFIG_SMP and the ipl cpu is logical cpu 0, it must be 1.
232  */
233 #define CPU_INIT_NO     1
234
235 #if defined(CONFIG_ZFCPDUMP) || defined(CONFIG_ZFCPDUMP_MODULE)
236
237 /*
238  * zfcpdump_prefix_array holds prefix registers for the following scenario:
239  * 64 bit zfcpdump kernel and 31 bit kernel which is to be dumped. We have to
240  * save its prefix registers, since they get lost, when switching from 31 bit
241  * to 64 bit.
242  */
243 unsigned int zfcpdump_prefix_array[NR_CPUS + 1] \
244         __attribute__((__section__(".data")));
245
246 static void __init smp_get_save_area(unsigned int cpu, unsigned int phy_cpu)
247 {
248         if (ipl_info.type != IPL_TYPE_FCP_DUMP)
249                 return;
250         if (cpu >= NR_CPUS) {
251                 pr_warning("CPU %i exceeds the maximum %i and is excluded from "
252                            "the dump\n", cpu, NR_CPUS - 1);
253                 return;
254         }
255         zfcpdump_save_areas[cpu] = kmalloc(sizeof(union save_area), GFP_KERNEL);
256         __cpu_logical_map[CPU_INIT_NO] = (__u16) phy_cpu;
257         while (signal_processor(CPU_INIT_NO, sigp_stop_and_store_status) ==
258                sigp_busy)
259                 cpu_relax();
260         memcpy(zfcpdump_save_areas[cpu],
261                (void *)(unsigned long) store_prefix() + SAVE_AREA_BASE,
262                SAVE_AREA_SIZE);
263 #ifdef CONFIG_64BIT
264         /* copy original prefix register */
265         zfcpdump_save_areas[cpu]->s390x.pref_reg = zfcpdump_prefix_array[cpu];
266 #endif
267 }
268
269 union save_area *zfcpdump_save_areas[NR_CPUS + 1];
270 EXPORT_SYMBOL_GPL(zfcpdump_save_areas);
271
272 #else
273
274 static inline void smp_get_save_area(unsigned int cpu, unsigned int phy_cpu) { }
275
276 #endif /* CONFIG_ZFCPDUMP || CONFIG_ZFCPDUMP_MODULE */
277
278 static int cpu_stopped(int cpu)
279 {
280         __u32 status;
281
282         /* Check for stopped state */
283         if (signal_processor_ps(&status, 0, cpu, sigp_sense) ==
284             sigp_status_stored) {
285                 if (status & 0x40)
286                         return 1;
287         }
288         return 0;
289 }
290
291 static int cpu_known(int cpu_id)
292 {
293         int cpu;
294
295         for_each_present_cpu(cpu) {
296                 if (__cpu_logical_map[cpu] == cpu_id)
297                         return 1;
298         }
299         return 0;
300 }
301
302 static int smp_rescan_cpus_sigp(cpumask_t avail)
303 {
304         int cpu_id, logical_cpu;
305
306         logical_cpu = first_cpu(avail);
307         if (logical_cpu == NR_CPUS)
308                 return 0;
309         for (cpu_id = 0; cpu_id <= 65535; cpu_id++) {
310                 if (cpu_known(cpu_id))
311                         continue;
312                 __cpu_logical_map[logical_cpu] = cpu_id;
313                 smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN;
314                 if (!cpu_stopped(logical_cpu))
315                         continue;
316                 cpu_set(logical_cpu, cpu_present_map);
317                 smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
318                 logical_cpu = next_cpu(logical_cpu, avail);
319                 if (logical_cpu == NR_CPUS)
320                         break;
321         }
322         return 0;
323 }
324
325 static int smp_rescan_cpus_sclp(cpumask_t avail)
326 {
327         struct sclp_cpu_info *info;
328         int cpu_id, logical_cpu, cpu;
329         int rc;
330
331         logical_cpu = first_cpu(avail);
332         if (logical_cpu == NR_CPUS)
333                 return 0;
334         info = kmalloc(sizeof(*info), GFP_KERNEL);
335         if (!info)
336                 return -ENOMEM;
337         rc = sclp_get_cpu_info(info);
338         if (rc)
339                 goto out;
340         for (cpu = 0; cpu < info->combined; cpu++) {
341                 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
342                         continue;
343                 cpu_id = info->cpu[cpu].address;
344                 if (cpu_known(cpu_id))
345                         continue;
346                 __cpu_logical_map[logical_cpu] = cpu_id;
347                 smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN;
348                 cpu_set(logical_cpu, cpu_present_map);
349                 if (cpu >= info->configured)
350                         smp_cpu_state[logical_cpu] = CPU_STATE_STANDBY;
351                 else
352                         smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
353                 logical_cpu = next_cpu(logical_cpu, avail);
354                 if (logical_cpu == NR_CPUS)
355                         break;
356         }
357 out:
358         kfree(info);
359         return rc;
360 }
361
362 static int __smp_rescan_cpus(void)
363 {
364         cpumask_t avail;
365
366         cpus_xor(avail, cpu_possible_map, cpu_present_map);
367         if (smp_use_sigp_detection)
368                 return smp_rescan_cpus_sigp(avail);
369         else
370                 return smp_rescan_cpus_sclp(avail);
371 }
372
373 static void __init smp_detect_cpus(void)
374 {
375         unsigned int cpu, c_cpus, s_cpus;
376         struct sclp_cpu_info *info;
377         u16 boot_cpu_addr, cpu_addr;
378
379         c_cpus = 1;
380         s_cpus = 0;
381         boot_cpu_addr = S390_lowcore.cpu_data.cpu_addr;
382         info = kmalloc(sizeof(*info), GFP_KERNEL);
383         if (!info)
384                 panic("smp_detect_cpus failed to allocate memory\n");
385         /* Use sigp detection algorithm if sclp doesn't work. */
386         if (sclp_get_cpu_info(info)) {
387                 smp_use_sigp_detection = 1;
388                 for (cpu = 0; cpu <= 65535; cpu++) {
389                         if (cpu == boot_cpu_addr)
390                                 continue;
391                         __cpu_logical_map[CPU_INIT_NO] = cpu;
392                         if (!cpu_stopped(CPU_INIT_NO))
393                                 continue;
394                         smp_get_save_area(c_cpus, cpu);
395                         c_cpus++;
396                 }
397                 goto out;
398         }
399
400         if (info->has_cpu_type) {
401                 for (cpu = 0; cpu < info->combined; cpu++) {
402                         if (info->cpu[cpu].address == boot_cpu_addr) {
403                                 smp_cpu_type = info->cpu[cpu].type;
404                                 break;
405                         }
406                 }
407         }
408
409         for (cpu = 0; cpu < info->combined; cpu++) {
410                 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
411                         continue;
412                 cpu_addr = info->cpu[cpu].address;
413                 if (cpu_addr == boot_cpu_addr)
414                         continue;
415                 __cpu_logical_map[CPU_INIT_NO] = cpu_addr;
416                 if (!cpu_stopped(CPU_INIT_NO)) {
417                         s_cpus++;
418                         continue;
419                 }
420                 smp_get_save_area(c_cpus, cpu_addr);
421                 c_cpus++;
422         }
423 out:
424         kfree(info);
425         pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
426         get_online_cpus();
427         __smp_rescan_cpus();
428         put_online_cpus();
429 }
430
431 /*
432  *      Activate a secondary processor.
433  */
434 int __cpuinit start_secondary(void *cpuvoid)
435 {
436         /* Setup the cpu */
437         cpu_init();
438         preempt_disable();
439         /* Enable TOD clock interrupts on the secondary cpu. */
440         init_cpu_timer();
441         /* Enable cpu timer interrupts on the secondary cpu. */
442         init_cpu_vtimer();
443         /* Enable pfault pseudo page faults on this cpu. */
444         pfault_init();
445
446         /* call cpu notifiers */
447         notify_cpu_starting(smp_processor_id());
448         /* Mark this cpu as online */
449         ipi_call_lock();
450         cpu_set(smp_processor_id(), cpu_online_map);
451         ipi_call_unlock();
452         /* Switch on interrupts */
453         local_irq_enable();
454         /* Print info about this processor */
455         print_cpu_info(&S390_lowcore.cpu_data);
456         /* cpu_idle will call schedule for us */
457         cpu_idle();
458         return 0;
459 }
460
461 static void __init smp_create_idle(unsigned int cpu)
462 {
463         struct task_struct *p;
464
465         /*
466          *  don't care about the psw and regs settings since we'll never
467          *  reschedule the forked task.
468          */
469         p = fork_idle(cpu);
470         if (IS_ERR(p))
471                 panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p));
472         current_set[cpu] = p;
473 }
474
475 static int __cpuinit smp_alloc_lowcore(int cpu)
476 {
477         unsigned long async_stack, panic_stack;
478         struct _lowcore *lowcore;
479         int lc_order;
480
481         lc_order = sizeof(long) == 8 ? 1 : 0;
482         lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, lc_order);
483         if (!lowcore)
484                 return -ENOMEM;
485         async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
486         panic_stack = __get_free_page(GFP_KERNEL);
487         if (!panic_stack || !async_stack)
488                 goto out;
489         memcpy(lowcore, &S390_lowcore, 512);
490         memset((char *)lowcore + 512, 0, sizeof(*lowcore) - 512);
491         lowcore->async_stack = async_stack + ASYNC_SIZE;
492         lowcore->panic_stack = panic_stack + PAGE_SIZE;
493
494 #ifndef CONFIG_64BIT
495         if (MACHINE_HAS_IEEE) {
496                 unsigned long save_area;
497
498                 save_area = get_zeroed_page(GFP_KERNEL);
499                 if (!save_area)
500                         goto out;
501                 lowcore->extended_save_area_addr = (u32) save_area;
502         }
503 #endif
504         lowcore_ptr[cpu] = lowcore;
505         return 0;
506
507 out:
508         free_page(panic_stack);
509         free_pages(async_stack, ASYNC_ORDER);
510         free_pages((unsigned long) lowcore, lc_order);
511         return -ENOMEM;
512 }
513
514 #ifdef CONFIG_HOTPLUG_CPU
515 static void smp_free_lowcore(int cpu)
516 {
517         struct _lowcore *lowcore;
518         int lc_order;
519
520         lc_order = sizeof(long) == 8 ? 1 : 0;
521         lowcore = lowcore_ptr[cpu];
522 #ifndef CONFIG_64BIT
523         if (MACHINE_HAS_IEEE)
524                 free_page((unsigned long) lowcore->extended_save_area_addr);
525 #endif
526         free_page(lowcore->panic_stack - PAGE_SIZE);
527         free_pages(lowcore->async_stack - ASYNC_SIZE, ASYNC_ORDER);
528         free_pages((unsigned long) lowcore, lc_order);
529         lowcore_ptr[cpu] = NULL;
530 }
531 #endif /* CONFIG_HOTPLUG_CPU */
532
533 /* Upping and downing of CPUs */
534 int __cpuinit __cpu_up(unsigned int cpu)
535 {
536         struct task_struct *idle;
537         struct _lowcore *cpu_lowcore;
538         struct stack_frame *sf;
539         sigp_ccode ccode;
540
541         if (smp_cpu_state[cpu] != CPU_STATE_CONFIGURED)
542                 return -EIO;
543         if (smp_alloc_lowcore(cpu))
544                 return -ENOMEM;
545
546         ccode = signal_processor_p((__u32)(unsigned long)(lowcore_ptr[cpu]),
547                                    cpu, sigp_set_prefix);
548         if (ccode)
549                 return -EIO;
550
551         idle = current_set[cpu];
552         cpu_lowcore = lowcore_ptr[cpu];
553         cpu_lowcore->kernel_stack = (unsigned long)
554                 task_stack_page(idle) + THREAD_SIZE;
555         cpu_lowcore->thread_info = (unsigned long) task_thread_info(idle);
556         sf = (struct stack_frame *) (cpu_lowcore->kernel_stack
557                                      - sizeof(struct pt_regs)
558                                      - sizeof(struct stack_frame));
559         memset(sf, 0, sizeof(struct stack_frame));
560         sf->gprs[9] = (unsigned long) sf;
561         cpu_lowcore->save_area[15] = (unsigned long) sf;
562         __ctl_store(cpu_lowcore->cregs_save_area, 0, 15);
563         asm volatile(
564                 "       stam    0,15,0(%0)"
565                 : : "a" (&cpu_lowcore->access_regs_save_area) : "memory");
566         cpu_lowcore->percpu_offset = __per_cpu_offset[cpu];
567         cpu_lowcore->current_task = (unsigned long) idle;
568         cpu_lowcore->cpu_data.cpu_nr = cpu;
569         cpu_lowcore->kernel_asce = S390_lowcore.kernel_asce;
570         cpu_lowcore->ipl_device = S390_lowcore.ipl_device;
571         eieio();
572
573         while (signal_processor(cpu, sigp_restart) == sigp_busy)
574                 udelay(10);
575
576         while (!cpu_online(cpu))
577                 cpu_relax();
578         return 0;
579 }
580
581 static int __init setup_possible_cpus(char *s)
582 {
583         int pcpus, cpu;
584
585         pcpus = simple_strtoul(s, NULL, 0);
586         cpu_possible_map = cpumask_of_cpu(0);
587         for (cpu = 1; cpu < pcpus && cpu < NR_CPUS; cpu++)
588                 cpu_set(cpu, cpu_possible_map);
589         return 0;
590 }
591 early_param("possible_cpus", setup_possible_cpus);
592
593 #ifdef CONFIG_HOTPLUG_CPU
594
595 int __cpu_disable(void)
596 {
597         struct ec_creg_mask_parms cr_parms;
598         int cpu = smp_processor_id();
599
600         cpu_clear(cpu, cpu_online_map);
601
602         /* Disable pfault pseudo page faults on this cpu. */
603         pfault_fini();
604
605         memset(&cr_parms.orvals, 0, sizeof(cr_parms.orvals));
606         memset(&cr_parms.andvals, 0xff, sizeof(cr_parms.andvals));
607
608         /* disable all external interrupts */
609         cr_parms.orvals[0] = 0;
610         cr_parms.andvals[0] = ~(1 << 15 | 1 << 14 | 1 << 13 | 1 << 12 |
611                                 1 << 11 | 1 << 10 | 1 <<  6 | 1 <<  4);
612         /* disable all I/O interrupts */
613         cr_parms.orvals[6] = 0;
614         cr_parms.andvals[6] = ~(1 << 31 | 1 << 30 | 1 << 29 | 1 << 28 |
615                                 1 << 27 | 1 << 26 | 1 << 25 | 1 << 24);
616         /* disable most machine checks */
617         cr_parms.orvals[14] = 0;
618         cr_parms.andvals[14] = ~(1 << 28 | 1 << 27 | 1 << 26 |
619                                  1 << 25 | 1 << 24);
620
621         smp_ctl_bit_callback(&cr_parms);
622
623         return 0;
624 }
625
626 void __cpu_die(unsigned int cpu)
627 {
628         /* Wait until target cpu is down */
629         while (!smp_cpu_not_running(cpu))
630                 cpu_relax();
631         smp_free_lowcore(cpu);
632         pr_info("Processor %d stopped\n", cpu);
633 }
634
635 void cpu_die(void)
636 {
637         idle_task_exit();
638         signal_processor(smp_processor_id(), sigp_stop);
639         BUG();
640         for (;;);
641 }
642
643 #endif /* CONFIG_HOTPLUG_CPU */
644
645 void __init smp_prepare_cpus(unsigned int max_cpus)
646 {
647 #ifndef CONFIG_64BIT
648         unsigned long save_area = 0;
649 #endif
650         unsigned long async_stack, panic_stack;
651         struct _lowcore *lowcore;
652         unsigned int cpu;
653         int lc_order;
654
655         smp_detect_cpus();
656
657         /* request the 0x1201 emergency signal external interrupt */
658         if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0)
659                 panic("Couldn't request external interrupt 0x1201");
660         print_cpu_info(&S390_lowcore.cpu_data);
661
662         /* Reallocate current lowcore, but keep its contents. */
663         lc_order = sizeof(long) == 8 ? 1 : 0;
664         lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, lc_order);
665         panic_stack = __get_free_page(GFP_KERNEL);
666         async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
667 #ifndef CONFIG_64BIT
668         if (MACHINE_HAS_IEEE)
669                 save_area = get_zeroed_page(GFP_KERNEL);
670 #endif
671         local_irq_disable();
672         local_mcck_disable();
673         lowcore_ptr[smp_processor_id()] = lowcore;
674         *lowcore = S390_lowcore;
675         lowcore->panic_stack = panic_stack + PAGE_SIZE;
676         lowcore->async_stack = async_stack + ASYNC_SIZE;
677 #ifndef CONFIG_64BIT
678         if (MACHINE_HAS_IEEE)
679                 lowcore->extended_save_area_addr = (u32) save_area;
680 #endif
681         set_prefix((u32)(unsigned long) lowcore);
682         local_mcck_enable();
683         local_irq_enable();
684         for_each_possible_cpu(cpu)
685                 if (cpu != smp_processor_id())
686                         smp_create_idle(cpu);
687 }
688
689 void __init smp_prepare_boot_cpu(void)
690 {
691         BUG_ON(smp_processor_id() != 0);
692
693         current_thread_info()->cpu = 0;
694         cpu_set(0, cpu_present_map);
695         cpu_set(0, cpu_online_map);
696         S390_lowcore.percpu_offset = __per_cpu_offset[0];
697         current_set[0] = current;
698         smp_cpu_state[0] = CPU_STATE_CONFIGURED;
699         smp_cpu_polarization[0] = POLARIZATION_UNKNWN;
700 }
701
702 void __init smp_cpus_done(unsigned int max_cpus)
703 {
704 }
705
706 /*
707  * the frequency of the profiling timer can be changed
708  * by writing a multiplier value into /proc/profile.
709  *
710  * usually you want to run this on all CPUs ;)
711  */
712 int setup_profiling_timer(unsigned int multiplier)
713 {
714         return 0;
715 }
716
717 #ifdef CONFIG_HOTPLUG_CPU
718 static ssize_t cpu_configure_show(struct sys_device *dev,
719                                 struct sysdev_attribute *attr, char *buf)
720 {
721         ssize_t count;
722
723         mutex_lock(&smp_cpu_state_mutex);
724         count = sprintf(buf, "%d\n", smp_cpu_state[dev->id]);
725         mutex_unlock(&smp_cpu_state_mutex);
726         return count;
727 }
728
729 static ssize_t cpu_configure_store(struct sys_device *dev,
730                                   struct sysdev_attribute *attr,
731                                   const char *buf, size_t count)
732 {
733         int cpu = dev->id;
734         int val, rc;
735         char delim;
736
737         if (sscanf(buf, "%d %c", &val, &delim) != 1)
738                 return -EINVAL;
739         if (val != 0 && val != 1)
740                 return -EINVAL;
741
742         get_online_cpus();
743         mutex_lock(&smp_cpu_state_mutex);
744         rc = -EBUSY;
745         if (cpu_online(cpu))
746                 goto out;
747         rc = 0;
748         switch (val) {
749         case 0:
750                 if (smp_cpu_state[cpu] == CPU_STATE_CONFIGURED) {
751                         rc = sclp_cpu_deconfigure(__cpu_logical_map[cpu]);
752                         if (!rc) {
753                                 smp_cpu_state[cpu] = CPU_STATE_STANDBY;
754                                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
755                         }
756                 }
757                 break;
758         case 1:
759                 if (smp_cpu_state[cpu] == CPU_STATE_STANDBY) {
760                         rc = sclp_cpu_configure(__cpu_logical_map[cpu]);
761                         if (!rc) {
762                                 smp_cpu_state[cpu] = CPU_STATE_CONFIGURED;
763                                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
764                         }
765                 }
766                 break;
767         default:
768                 break;
769         }
770 out:
771         mutex_unlock(&smp_cpu_state_mutex);
772         put_online_cpus();
773         return rc ? rc : count;
774 }
775 static SYSDEV_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
776 #endif /* CONFIG_HOTPLUG_CPU */
777
778 static ssize_t cpu_polarization_show(struct sys_device *dev,
779                                      struct sysdev_attribute *attr, char *buf)
780 {
781         int cpu = dev->id;
782         ssize_t count;
783
784         mutex_lock(&smp_cpu_state_mutex);
785         switch (smp_cpu_polarization[cpu]) {
786         case POLARIZATION_HRZ:
787                 count = sprintf(buf, "horizontal\n");
788                 break;
789         case POLARIZATION_VL:
790                 count = sprintf(buf, "vertical:low\n");
791                 break;
792         case POLARIZATION_VM:
793                 count = sprintf(buf, "vertical:medium\n");
794                 break;
795         case POLARIZATION_VH:
796                 count = sprintf(buf, "vertical:high\n");
797                 break;
798         default:
799                 count = sprintf(buf, "unknown\n");
800                 break;
801         }
802         mutex_unlock(&smp_cpu_state_mutex);
803         return count;
804 }
805 static SYSDEV_ATTR(polarization, 0444, cpu_polarization_show, NULL);
806
807 static ssize_t show_cpu_address(struct sys_device *dev,
808                                 struct sysdev_attribute *attr, char *buf)
809 {
810         return sprintf(buf, "%d\n", __cpu_logical_map[dev->id]);
811 }
812 static SYSDEV_ATTR(address, 0444, show_cpu_address, NULL);
813
814
815 static struct attribute *cpu_common_attrs[] = {
816 #ifdef CONFIG_HOTPLUG_CPU
817         &attr_configure.attr,
818 #endif
819         &attr_address.attr,
820         &attr_polarization.attr,
821         NULL,
822 };
823
824 static struct attribute_group cpu_common_attr_group = {
825         .attrs = cpu_common_attrs,
826 };
827
828 static ssize_t show_capability(struct sys_device *dev,
829                                 struct sysdev_attribute *attr, char *buf)
830 {
831         unsigned int capability;
832         int rc;
833
834         rc = get_cpu_capability(&capability);
835         if (rc)
836                 return rc;
837         return sprintf(buf, "%u\n", capability);
838 }
839 static SYSDEV_ATTR(capability, 0444, show_capability, NULL);
840
841 static ssize_t show_idle_count(struct sys_device *dev,
842                                 struct sysdev_attribute *attr, char *buf)
843 {
844         struct s390_idle_data *idle;
845         unsigned long long idle_count;
846
847         idle = &per_cpu(s390_idle, dev->id);
848         spin_lock_irq(&idle->lock);
849         idle_count = idle->idle_count;
850         spin_unlock_irq(&idle->lock);
851         return sprintf(buf, "%llu\n", idle_count);
852 }
853 static SYSDEV_ATTR(idle_count, 0444, show_idle_count, NULL);
854
855 static ssize_t show_idle_time(struct sys_device *dev,
856                                 struct sysdev_attribute *attr, char *buf)
857 {
858         struct s390_idle_data *idle;
859         unsigned long long new_time;
860
861         idle = &per_cpu(s390_idle, dev->id);
862         spin_lock_irq(&idle->lock);
863         if (idle->in_idle) {
864                 new_time = get_clock();
865                 idle->idle_time += new_time - idle->idle_enter;
866                 idle->idle_enter = new_time;
867         }
868         new_time = idle->idle_time;
869         spin_unlock_irq(&idle->lock);
870         return sprintf(buf, "%llu\n", new_time >> 12);
871 }
872 static SYSDEV_ATTR(idle_time_us, 0444, show_idle_time, NULL);
873
874 static struct attribute *cpu_online_attrs[] = {
875         &attr_capability.attr,
876         &attr_idle_count.attr,
877         &attr_idle_time_us.attr,
878         NULL,
879 };
880
881 static struct attribute_group cpu_online_attr_group = {
882         .attrs = cpu_online_attrs,
883 };
884
885 static int __cpuinit smp_cpu_notify(struct notifier_block *self,
886                                     unsigned long action, void *hcpu)
887 {
888         unsigned int cpu = (unsigned int)(long)hcpu;
889         struct cpu *c = &per_cpu(cpu_devices, cpu);
890         struct sys_device *s = &c->sysdev;
891         struct s390_idle_data *idle;
892
893         switch (action) {
894         case CPU_ONLINE:
895         case CPU_ONLINE_FROZEN:
896                 idle = &per_cpu(s390_idle, cpu);
897                 spin_lock_irq(&idle->lock);
898                 idle->idle_enter = 0;
899                 idle->idle_time = 0;
900                 idle->idle_count = 0;
901                 spin_unlock_irq(&idle->lock);
902                 if (sysfs_create_group(&s->kobj, &cpu_online_attr_group))
903                         return NOTIFY_BAD;
904                 break;
905         case CPU_DEAD:
906         case CPU_DEAD_FROZEN:
907                 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
908                 break;
909         }
910         return NOTIFY_OK;
911 }
912
913 static struct notifier_block __cpuinitdata smp_cpu_nb = {
914         .notifier_call = smp_cpu_notify,
915 };
916
917 static int __devinit smp_add_present_cpu(int cpu)
918 {
919         struct cpu *c = &per_cpu(cpu_devices, cpu);
920         struct sys_device *s = &c->sysdev;
921         int rc;
922
923         c->hotpluggable = 1;
924         rc = register_cpu(c, cpu);
925         if (rc)
926                 goto out;
927         rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
928         if (rc)
929                 goto out_cpu;
930         if (!cpu_online(cpu))
931                 goto out;
932         rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
933         if (!rc)
934                 return 0;
935         sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
936 out_cpu:
937 #ifdef CONFIG_HOTPLUG_CPU
938         unregister_cpu(c);
939 #endif
940 out:
941         return rc;
942 }
943
944 #ifdef CONFIG_HOTPLUG_CPU
945
946 int __ref smp_rescan_cpus(void)
947 {
948         cpumask_t newcpus;
949         int cpu;
950         int rc;
951
952         get_online_cpus();
953         mutex_lock(&smp_cpu_state_mutex);
954         newcpus = cpu_present_map;
955         rc = __smp_rescan_cpus();
956         if (rc)
957                 goto out;
958         cpus_andnot(newcpus, cpu_present_map, newcpus);
959         for_each_cpu_mask(cpu, newcpus) {
960                 rc = smp_add_present_cpu(cpu);
961                 if (rc)
962                         cpu_clear(cpu, cpu_present_map);
963         }
964         rc = 0;
965 out:
966         mutex_unlock(&smp_cpu_state_mutex);
967         put_online_cpus();
968         if (!cpus_empty(newcpus))
969                 topology_schedule_update();
970         return rc;
971 }
972
973 static ssize_t __ref rescan_store(struct sysdev_class *class, const char *buf,
974                                   size_t count)
975 {
976         int rc;
977
978         rc = smp_rescan_cpus();
979         return rc ? rc : count;
980 }
981 static SYSDEV_CLASS_ATTR(rescan, 0200, NULL, rescan_store);
982 #endif /* CONFIG_HOTPLUG_CPU */
983
984 static ssize_t dispatching_show(struct sysdev_class *class, char *buf)
985 {
986         ssize_t count;
987
988         mutex_lock(&smp_cpu_state_mutex);
989         count = sprintf(buf, "%d\n", cpu_management);
990         mutex_unlock(&smp_cpu_state_mutex);
991         return count;
992 }
993
994 static ssize_t dispatching_store(struct sysdev_class *dev, const char *buf,
995                                  size_t count)
996 {
997         int val, rc;
998         char delim;
999
1000         if (sscanf(buf, "%d %c", &val, &delim) != 1)
1001                 return -EINVAL;
1002         if (val != 0 && val != 1)
1003                 return -EINVAL;
1004         rc = 0;
1005         get_online_cpus();
1006         mutex_lock(&smp_cpu_state_mutex);
1007         if (cpu_management == val)
1008                 goto out;
1009         rc = topology_set_cpu_management(val);
1010         if (!rc)
1011                 cpu_management = val;
1012 out:
1013         mutex_unlock(&smp_cpu_state_mutex);
1014         put_online_cpus();
1015         return rc ? rc : count;
1016 }
1017 static SYSDEV_CLASS_ATTR(dispatching, 0644, dispatching_show,
1018                          dispatching_store);
1019
1020 static int __init topology_init(void)
1021 {
1022         int cpu;
1023         int rc;
1024
1025         register_cpu_notifier(&smp_cpu_nb);
1026
1027 #ifdef CONFIG_HOTPLUG_CPU
1028         rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_rescan);
1029         if (rc)
1030                 return rc;
1031 #endif
1032         rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_dispatching);
1033         if (rc)
1034                 return rc;
1035         for_each_present_cpu(cpu) {
1036                 rc = smp_add_present_cpu(cpu);
1037                 if (rc)
1038                         return rc;
1039         }
1040         return 0;
1041 }
1042 subsys_initcall(topology_init);