Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6
[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/irqflags.h>
36 #include <linux/cpu.h>
37 #include <linux/timex.h>
38 #include <linux/bootmem.h>
39 #include <asm/ipl.h>
40 #include <asm/setup.h>
41 #include <asm/sigp.h>
42 #include <asm/pgalloc.h>
43 #include <asm/irq.h>
44 #include <asm/s390_ext.h>
45 #include <asm/cpcmd.h>
46 #include <asm/tlbflush.h>
47 #include <asm/timer.h>
48 #include <asm/lowcore.h>
49 #include <asm/sclp.h>
50 #include <asm/cpu.h>
51 #include <asm/vdso.h>
52 #include "entry.h"
53
54 static struct task_struct *current_set[NR_CPUS];
55
56 static u8 smp_cpu_type;
57 static int smp_use_sigp_detection;
58
59 enum s390_cpu_state {
60         CPU_STATE_STANDBY,
61         CPU_STATE_CONFIGURED,
62 };
63
64 DEFINE_MUTEX(smp_cpu_state_mutex);
65 int smp_cpu_polarization[NR_CPUS];
66 static int smp_cpu_state[NR_CPUS];
67 static int cpu_management;
68
69 static DEFINE_PER_CPU(struct cpu, cpu_devices);
70
71 static void smp_ext_bitcall(int, ec_bit_sig);
72
73 void smp_send_stop(void)
74 {
75         int cpu, rc;
76
77         /* Disable all interrupts/machine checks */
78         __load_psw_mask(psw_kernel_bits & ~PSW_MASK_MCHECK);
79         trace_hardirqs_off();
80
81         /* stop all processors */
82         for_each_online_cpu(cpu) {
83                 if (cpu == smp_processor_id())
84                         continue;
85                 do {
86                         rc = signal_processor(cpu, sigp_stop);
87                 } while (rc == sigp_busy);
88
89                 while (!smp_cpu_not_running(cpu))
90                         cpu_relax();
91         }
92 }
93
94 /*
95  * This is the main routine where commands issued by other
96  * cpus are handled.
97  */
98
99 static void do_ext_call_interrupt(__u16 code)
100 {
101         unsigned long bits;
102
103         /*
104          * handle bit signal external calls
105          *
106          * For the ec_schedule signal we have to do nothing. All the work
107          * is done automatically when we return from the interrupt.
108          */
109         bits = xchg(&S390_lowcore.ext_call_fast, 0);
110
111         if (test_bit(ec_call_function, &bits))
112                 generic_smp_call_function_interrupt();
113
114         if (test_bit(ec_call_function_single, &bits))
115                 generic_smp_call_function_single_interrupt();
116 }
117
118 /*
119  * Send an external call sigp to another cpu and return without waiting
120  * for its completion.
121  */
122 static void smp_ext_bitcall(int cpu, ec_bit_sig sig)
123 {
124         /*
125          * Set signaling bit in lowcore of target cpu and kick it
126          */
127         set_bit(sig, (unsigned long *) &lowcore_ptr[cpu]->ext_call_fast);
128         while (signal_processor(cpu, sigp_emergency_signal) == sigp_busy)
129                 udelay(10);
130 }
131
132 void arch_send_call_function_ipi(cpumask_t mask)
133 {
134         int cpu;
135
136         for_each_cpu_mask(cpu, mask)
137                 smp_ext_bitcall(cpu, ec_call_function);
138 }
139
140 void arch_send_call_function_single_ipi(int cpu)
141 {
142         smp_ext_bitcall(cpu, ec_call_function_single);
143 }
144
145 #ifndef CONFIG_64BIT
146 /*
147  * this function sends a 'purge tlb' signal to another CPU.
148  */
149 static void smp_ptlb_callback(void *info)
150 {
151         __tlb_flush_local();
152 }
153
154 void smp_ptlb_all(void)
155 {
156         on_each_cpu(smp_ptlb_callback, NULL, 1);
157 }
158 EXPORT_SYMBOL(smp_ptlb_all);
159 #endif /* ! CONFIG_64BIT */
160
161 /*
162  * this function sends a 'reschedule' IPI to another CPU.
163  * it goes straight through and wastes no time serializing
164  * anything. Worst case is that we lose a reschedule ...
165  */
166 void smp_send_reschedule(int cpu)
167 {
168         smp_ext_bitcall(cpu, ec_schedule);
169 }
170
171 /*
172  * parameter area for the set/clear control bit callbacks
173  */
174 struct ec_creg_mask_parms {
175         unsigned long orvals[16];
176         unsigned long andvals[16];
177 };
178
179 /*
180  * callback for setting/clearing control bits
181  */
182 static void smp_ctl_bit_callback(void *info)
183 {
184         struct ec_creg_mask_parms *pp = info;
185         unsigned long cregs[16];
186         int i;
187
188         __ctl_store(cregs, 0, 15);
189         for (i = 0; i <= 15; i++)
190                 cregs[i] = (cregs[i] & pp->andvals[i]) | pp->orvals[i];
191         __ctl_load(cregs, 0, 15);
192 }
193
194 /*
195  * Set a bit in a control register of all cpus
196  */
197 void smp_ctl_set_bit(int cr, int bit)
198 {
199         struct ec_creg_mask_parms parms;
200
201         memset(&parms.orvals, 0, sizeof(parms.orvals));
202         memset(&parms.andvals, 0xff, sizeof(parms.andvals));
203         parms.orvals[cr] = 1 << bit;
204         on_each_cpu(smp_ctl_bit_callback, &parms, 1);
205 }
206 EXPORT_SYMBOL(smp_ctl_set_bit);
207
208 /*
209  * Clear a bit in a control register of all cpus
210  */
211 void smp_ctl_clear_bit(int cr, int bit)
212 {
213         struct ec_creg_mask_parms parms;
214
215         memset(&parms.orvals, 0, sizeof(parms.orvals));
216         memset(&parms.andvals, 0xff, sizeof(parms.andvals));
217         parms.andvals[cr] = ~(1L << bit);
218         on_each_cpu(smp_ctl_bit_callback, &parms, 1);
219 }
220 EXPORT_SYMBOL(smp_ctl_clear_bit);
221
222 /*
223  * In early ipl state a temp. logically cpu number is needed, so the sigp
224  * functions can be used to sense other cpus. Since NR_CPUS is >= 2 on
225  * CONFIG_SMP and the ipl cpu is logical cpu 0, it must be 1.
226  */
227 #define CPU_INIT_NO     1
228
229 #ifdef CONFIG_ZFCPDUMP
230
231 /*
232  * zfcpdump_prefix_array holds prefix registers for the following scenario:
233  * 64 bit zfcpdump kernel and 31 bit kernel which is to be dumped. We have to
234  * save its prefix registers, since they get lost, when switching from 31 bit
235  * to 64 bit.
236  */
237 unsigned int zfcpdump_prefix_array[NR_CPUS + 1] \
238         __attribute__((__section__(".data")));
239
240 static void __init smp_get_save_area(unsigned int cpu, unsigned int phy_cpu)
241 {
242         if (ipl_info.type != IPL_TYPE_FCP_DUMP)
243                 return;
244         if (cpu >= NR_CPUS) {
245                 pr_warning("CPU %i exceeds the maximum %i and is excluded from "
246                            "the dump\n", cpu, NR_CPUS - 1);
247                 return;
248         }
249         zfcpdump_save_areas[cpu] = kmalloc(sizeof(union save_area), GFP_KERNEL);
250         __cpu_logical_map[CPU_INIT_NO] = (__u16) phy_cpu;
251         while (signal_processor(CPU_INIT_NO, sigp_stop_and_store_status) ==
252                sigp_busy)
253                 cpu_relax();
254         memcpy(zfcpdump_save_areas[cpu],
255                (void *)(unsigned long) store_prefix() + SAVE_AREA_BASE,
256                SAVE_AREA_SIZE);
257 #ifdef CONFIG_64BIT
258         /* copy original prefix register */
259         zfcpdump_save_areas[cpu]->s390x.pref_reg = zfcpdump_prefix_array[cpu];
260 #endif
261 }
262
263 union save_area *zfcpdump_save_areas[NR_CPUS + 1];
264 EXPORT_SYMBOL_GPL(zfcpdump_save_areas);
265
266 #else
267
268 static inline void smp_get_save_area(unsigned int cpu, unsigned int phy_cpu) { }
269
270 #endif /* CONFIG_ZFCPDUMP */
271
272 static int cpu_stopped(int cpu)
273 {
274         __u32 status;
275
276         /* Check for stopped state */
277         if (signal_processor_ps(&status, 0, cpu, sigp_sense) ==
278             sigp_status_stored) {
279                 if (status & 0x40)
280                         return 1;
281         }
282         return 0;
283 }
284
285 static int cpu_known(int cpu_id)
286 {
287         int cpu;
288
289         for_each_present_cpu(cpu) {
290                 if (__cpu_logical_map[cpu] == cpu_id)
291                         return 1;
292         }
293         return 0;
294 }
295
296 static int smp_rescan_cpus_sigp(cpumask_t avail)
297 {
298         int cpu_id, logical_cpu;
299
300         logical_cpu = cpumask_first(&avail);
301         if (logical_cpu >= nr_cpu_ids)
302                 return 0;
303         for (cpu_id = 0; cpu_id <= 65535; cpu_id++) {
304                 if (cpu_known(cpu_id))
305                         continue;
306                 __cpu_logical_map[logical_cpu] = cpu_id;
307                 smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN;
308                 if (!cpu_stopped(logical_cpu))
309                         continue;
310                 cpu_set(logical_cpu, cpu_present_map);
311                 smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
312                 logical_cpu = cpumask_next(logical_cpu, &avail);
313                 if (logical_cpu >= nr_cpu_ids)
314                         break;
315         }
316         return 0;
317 }
318
319 static int smp_rescan_cpus_sclp(cpumask_t avail)
320 {
321         struct sclp_cpu_info *info;
322         int cpu_id, logical_cpu, cpu;
323         int rc;
324
325         logical_cpu = cpumask_first(&avail);
326         if (logical_cpu >= nr_cpu_ids)
327                 return 0;
328         info = kmalloc(sizeof(*info), GFP_KERNEL);
329         if (!info)
330                 return -ENOMEM;
331         rc = sclp_get_cpu_info(info);
332         if (rc)
333                 goto out;
334         for (cpu = 0; cpu < info->combined; cpu++) {
335                 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
336                         continue;
337                 cpu_id = info->cpu[cpu].address;
338                 if (cpu_known(cpu_id))
339                         continue;
340                 __cpu_logical_map[logical_cpu] = cpu_id;
341                 smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN;
342                 cpu_set(logical_cpu, cpu_present_map);
343                 if (cpu >= info->configured)
344                         smp_cpu_state[logical_cpu] = CPU_STATE_STANDBY;
345                 else
346                         smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
347                 logical_cpu = cpumask_next(logical_cpu, &avail);
348                 if (logical_cpu >= nr_cpu_ids)
349                         break;
350         }
351 out:
352         kfree(info);
353         return rc;
354 }
355
356 static int __smp_rescan_cpus(void)
357 {
358         cpumask_t avail;
359
360         cpus_xor(avail, cpu_possible_map, cpu_present_map);
361         if (smp_use_sigp_detection)
362                 return smp_rescan_cpus_sigp(avail);
363         else
364                 return smp_rescan_cpus_sclp(avail);
365 }
366
367 static void __init smp_detect_cpus(void)
368 {
369         unsigned int cpu, c_cpus, s_cpus;
370         struct sclp_cpu_info *info;
371         u16 boot_cpu_addr, cpu_addr;
372
373         c_cpus = 1;
374         s_cpus = 0;
375         boot_cpu_addr = __cpu_logical_map[0];
376         info = kmalloc(sizeof(*info), GFP_KERNEL);
377         if (!info)
378                 panic("smp_detect_cpus failed to allocate memory\n");
379         /* Use sigp detection algorithm if sclp doesn't work. */
380         if (sclp_get_cpu_info(info)) {
381                 smp_use_sigp_detection = 1;
382                 for (cpu = 0; cpu <= 65535; cpu++) {
383                         if (cpu == boot_cpu_addr)
384                                 continue;
385                         __cpu_logical_map[CPU_INIT_NO] = cpu;
386                         if (!cpu_stopped(CPU_INIT_NO))
387                                 continue;
388                         smp_get_save_area(c_cpus, cpu);
389                         c_cpus++;
390                 }
391                 goto out;
392         }
393
394         if (info->has_cpu_type) {
395                 for (cpu = 0; cpu < info->combined; cpu++) {
396                         if (info->cpu[cpu].address == boot_cpu_addr) {
397                                 smp_cpu_type = info->cpu[cpu].type;
398                                 break;
399                         }
400                 }
401         }
402
403         for (cpu = 0; cpu < info->combined; cpu++) {
404                 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
405                         continue;
406                 cpu_addr = info->cpu[cpu].address;
407                 if (cpu_addr == boot_cpu_addr)
408                         continue;
409                 __cpu_logical_map[CPU_INIT_NO] = cpu_addr;
410                 if (!cpu_stopped(CPU_INIT_NO)) {
411                         s_cpus++;
412                         continue;
413                 }
414                 smp_get_save_area(c_cpus, cpu_addr);
415                 c_cpus++;
416         }
417 out:
418         kfree(info);
419         pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
420         get_online_cpus();
421         __smp_rescan_cpus();
422         put_online_cpus();
423 }
424
425 /*
426  *      Activate a secondary processor.
427  */
428 int __cpuinit start_secondary(void *cpuvoid)
429 {
430         /* Setup the cpu */
431         cpu_init();
432         preempt_disable();
433         /* Enable TOD clock interrupts on the secondary cpu. */
434         init_cpu_timer();
435         /* Enable cpu timer interrupts on the secondary cpu. */
436         init_cpu_vtimer();
437         /* Enable pfault pseudo page faults on this cpu. */
438         pfault_init();
439
440         /* call cpu notifiers */
441         notify_cpu_starting(smp_processor_id());
442         /* Mark this cpu as online */
443         ipi_call_lock();
444         cpu_set(smp_processor_id(), cpu_online_map);
445         ipi_call_unlock();
446         /* Switch on interrupts */
447         local_irq_enable();
448         /* Print info about this processor */
449         print_cpu_info();
450         /* cpu_idle will call schedule for us */
451         cpu_idle();
452         return 0;
453 }
454
455 static void __init smp_create_idle(unsigned int cpu)
456 {
457         struct task_struct *p;
458
459         /*
460          *  don't care about the psw and regs settings since we'll never
461          *  reschedule the forked task.
462          */
463         p = fork_idle(cpu);
464         if (IS_ERR(p))
465                 panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p));
466         current_set[cpu] = p;
467 }
468
469 static int __cpuinit smp_alloc_lowcore(int cpu)
470 {
471         unsigned long async_stack, panic_stack;
472         struct _lowcore *lowcore;
473         int lc_order;
474
475         lc_order = sizeof(long) == 8 ? 1 : 0;
476         lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, lc_order);
477         if (!lowcore)
478                 return -ENOMEM;
479         async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
480         panic_stack = __get_free_page(GFP_KERNEL);
481         if (!panic_stack || !async_stack)
482                 goto out;
483         memcpy(lowcore, &S390_lowcore, 512);
484         memset((char *)lowcore + 512, 0, sizeof(*lowcore) - 512);
485         lowcore->async_stack = async_stack + ASYNC_SIZE;
486         lowcore->panic_stack = panic_stack + PAGE_SIZE;
487
488 #ifndef CONFIG_64BIT
489         if (MACHINE_HAS_IEEE) {
490                 unsigned long save_area;
491
492                 save_area = get_zeroed_page(GFP_KERNEL);
493                 if (!save_area)
494                         goto out;
495                 lowcore->extended_save_area_addr = (u32) save_area;
496         }
497 #else
498         if (vdso_alloc_per_cpu(cpu, lowcore))
499                 goto out;
500 #endif
501         lowcore_ptr[cpu] = lowcore;
502         return 0;
503
504 out:
505         free_page(panic_stack);
506         free_pages(async_stack, ASYNC_ORDER);
507         free_pages((unsigned long) lowcore, lc_order);
508         return -ENOMEM;
509 }
510
511 static void smp_free_lowcore(int cpu)
512 {
513         struct _lowcore *lowcore;
514         int lc_order;
515
516         lc_order = sizeof(long) == 8 ? 1 : 0;
517         lowcore = lowcore_ptr[cpu];
518 #ifndef CONFIG_64BIT
519         if (MACHINE_HAS_IEEE)
520                 free_page((unsigned long) lowcore->extended_save_area_addr);
521 #else
522         vdso_free_per_cpu(cpu, lowcore);
523 #endif
524         free_page(lowcore->panic_stack - PAGE_SIZE);
525         free_pages(lowcore->async_stack - ASYNC_SIZE, ASYNC_ORDER);
526         free_pages((unsigned long) lowcore, lc_order);
527         lowcore_ptr[cpu] = NULL;
528 }
529
530 /* Upping and downing of CPUs */
531 int __cpuinit __cpu_up(unsigned int cpu)
532 {
533         struct task_struct *idle;
534         struct _lowcore *cpu_lowcore;
535         struct stack_frame *sf;
536         sigp_ccode ccode;
537         u32 lowcore;
538
539         if (smp_cpu_state[cpu] != CPU_STATE_CONFIGURED)
540                 return -EIO;
541         if (smp_alloc_lowcore(cpu))
542                 return -ENOMEM;
543         do {
544                 ccode = signal_processor(cpu, sigp_initial_cpu_reset);
545                 if (ccode == sigp_busy)
546                         udelay(10);
547                 if (ccode == sigp_not_operational)
548                         goto err_out;
549         } while (ccode == sigp_busy);
550
551         lowcore = (u32)(unsigned long)lowcore_ptr[cpu];
552         while (signal_processor_p(lowcore, cpu, sigp_set_prefix) == sigp_busy)
553                 udelay(10);
554
555         idle = current_set[cpu];
556         cpu_lowcore = lowcore_ptr[cpu];
557         cpu_lowcore->kernel_stack = (unsigned long)
558                 task_stack_page(idle) + THREAD_SIZE;
559         cpu_lowcore->thread_info = (unsigned long) task_thread_info(idle);
560         sf = (struct stack_frame *) (cpu_lowcore->kernel_stack
561                                      - sizeof(struct pt_regs)
562                                      - sizeof(struct stack_frame));
563         memset(sf, 0, sizeof(struct stack_frame));
564         sf->gprs[9] = (unsigned long) sf;
565         cpu_lowcore->save_area[15] = (unsigned long) sf;
566         __ctl_store(cpu_lowcore->cregs_save_area, 0, 15);
567         asm volatile(
568                 "       stam    0,15,0(%0)"
569                 : : "a" (&cpu_lowcore->access_regs_save_area) : "memory");
570         cpu_lowcore->percpu_offset = __per_cpu_offset[cpu];
571         cpu_lowcore->current_task = (unsigned long) idle;
572         cpu_lowcore->cpu_nr = cpu;
573         cpu_lowcore->kernel_asce = S390_lowcore.kernel_asce;
574         eieio();
575
576         while (signal_processor(cpu, sigp_restart) == sigp_busy)
577                 udelay(10);
578
579         while (!cpu_online(cpu))
580                 cpu_relax();
581         return 0;
582
583 err_out:
584         smp_free_lowcore(cpu);
585         return -EIO;
586 }
587
588 static int __init setup_possible_cpus(char *s)
589 {
590         int pcpus, cpu;
591
592         pcpus = simple_strtoul(s, NULL, 0);
593         for (cpu = 0; cpu < pcpus && cpu < nr_cpu_ids; cpu++)
594                 set_cpu_possible(cpu, true);
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();
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         BUG_ON(!lowcore || !panic_stack || !async_stack);
674 #ifndef CONFIG_64BIT
675         if (MACHINE_HAS_IEEE)
676                 save_area = get_zeroed_page(GFP_KERNEL);
677 #endif
678         local_irq_disable();
679         local_mcck_disable();
680         lowcore_ptr[smp_processor_id()] = lowcore;
681         *lowcore = S390_lowcore;
682         lowcore->panic_stack = panic_stack + PAGE_SIZE;
683         lowcore->async_stack = async_stack + ASYNC_SIZE;
684 #ifndef CONFIG_64BIT
685         if (MACHINE_HAS_IEEE)
686                 lowcore->extended_save_area_addr = (u32) save_area;
687 #else
688         if (vdso_alloc_per_cpu(smp_processor_id(), lowcore))
689                 BUG();
690 #endif
691         set_prefix((u32)(unsigned long) lowcore);
692         local_mcck_enable();
693         local_irq_enable();
694         for_each_possible_cpu(cpu)
695                 if (cpu != smp_processor_id())
696                         smp_create_idle(cpu);
697 }
698
699 void __init smp_prepare_boot_cpu(void)
700 {
701         BUG_ON(smp_processor_id() != 0);
702
703         current_thread_info()->cpu = 0;
704         cpu_set(0, cpu_present_map);
705         cpu_set(0, cpu_online_map);
706         S390_lowcore.percpu_offset = __per_cpu_offset[0];
707         current_set[0] = current;
708         smp_cpu_state[0] = CPU_STATE_CONFIGURED;
709         smp_cpu_polarization[0] = POLARIZATION_UNKNWN;
710 }
711
712 void __init smp_cpus_done(unsigned int max_cpus)
713 {
714 }
715
716 /*
717  * the frequency of the profiling timer can be changed
718  * by writing a multiplier value into /proc/profile.
719  *
720  * usually you want to run this on all CPUs ;)
721  */
722 int setup_profiling_timer(unsigned int multiplier)
723 {
724         return 0;
725 }
726
727 #ifdef CONFIG_HOTPLUG_CPU
728 static ssize_t cpu_configure_show(struct sys_device *dev,
729                                 struct sysdev_attribute *attr, char *buf)
730 {
731         ssize_t count;
732
733         mutex_lock(&smp_cpu_state_mutex);
734         count = sprintf(buf, "%d\n", smp_cpu_state[dev->id]);
735         mutex_unlock(&smp_cpu_state_mutex);
736         return count;
737 }
738
739 static ssize_t cpu_configure_store(struct sys_device *dev,
740                                   struct sysdev_attribute *attr,
741                                   const char *buf, size_t count)
742 {
743         int cpu = dev->id;
744         int val, rc;
745         char delim;
746
747         if (sscanf(buf, "%d %c", &val, &delim) != 1)
748                 return -EINVAL;
749         if (val != 0 && val != 1)
750                 return -EINVAL;
751
752         get_online_cpus();
753         mutex_lock(&smp_cpu_state_mutex);
754         rc = -EBUSY;
755         if (cpu_online(cpu))
756                 goto out;
757         rc = 0;
758         switch (val) {
759         case 0:
760                 if (smp_cpu_state[cpu] == CPU_STATE_CONFIGURED) {
761                         rc = sclp_cpu_deconfigure(__cpu_logical_map[cpu]);
762                         if (!rc) {
763                                 smp_cpu_state[cpu] = CPU_STATE_STANDBY;
764                                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
765                         }
766                 }
767                 break;
768         case 1:
769                 if (smp_cpu_state[cpu] == CPU_STATE_STANDBY) {
770                         rc = sclp_cpu_configure(__cpu_logical_map[cpu]);
771                         if (!rc) {
772                                 smp_cpu_state[cpu] = CPU_STATE_CONFIGURED;
773                                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
774                         }
775                 }
776                 break;
777         default:
778                 break;
779         }
780 out:
781         mutex_unlock(&smp_cpu_state_mutex);
782         put_online_cpus();
783         return rc ? rc : count;
784 }
785 static SYSDEV_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
786 #endif /* CONFIG_HOTPLUG_CPU */
787
788 static ssize_t cpu_polarization_show(struct sys_device *dev,
789                                      struct sysdev_attribute *attr, char *buf)
790 {
791         int cpu = dev->id;
792         ssize_t count;
793
794         mutex_lock(&smp_cpu_state_mutex);
795         switch (smp_cpu_polarization[cpu]) {
796         case POLARIZATION_HRZ:
797                 count = sprintf(buf, "horizontal\n");
798                 break;
799         case POLARIZATION_VL:
800                 count = sprintf(buf, "vertical:low\n");
801                 break;
802         case POLARIZATION_VM:
803                 count = sprintf(buf, "vertical:medium\n");
804                 break;
805         case POLARIZATION_VH:
806                 count = sprintf(buf, "vertical:high\n");
807                 break;
808         default:
809                 count = sprintf(buf, "unknown\n");
810                 break;
811         }
812         mutex_unlock(&smp_cpu_state_mutex);
813         return count;
814 }
815 static SYSDEV_ATTR(polarization, 0444, cpu_polarization_show, NULL);
816
817 static ssize_t show_cpu_address(struct sys_device *dev,
818                                 struct sysdev_attribute *attr, char *buf)
819 {
820         return sprintf(buf, "%d\n", __cpu_logical_map[dev->id]);
821 }
822 static SYSDEV_ATTR(address, 0444, show_cpu_address, NULL);
823
824
825 static struct attribute *cpu_common_attrs[] = {
826 #ifdef CONFIG_HOTPLUG_CPU
827         &attr_configure.attr,
828 #endif
829         &attr_address.attr,
830         &attr_polarization.attr,
831         NULL,
832 };
833
834 static struct attribute_group cpu_common_attr_group = {
835         .attrs = cpu_common_attrs,
836 };
837
838 static ssize_t show_capability(struct sys_device *dev,
839                                 struct sysdev_attribute *attr, char *buf)
840 {
841         unsigned int capability;
842         int rc;
843
844         rc = get_cpu_capability(&capability);
845         if (rc)
846                 return rc;
847         return sprintf(buf, "%u\n", capability);
848 }
849 static SYSDEV_ATTR(capability, 0444, show_capability, NULL);
850
851 static ssize_t show_idle_count(struct sys_device *dev,
852                                 struct sysdev_attribute *attr, char *buf)
853 {
854         struct s390_idle_data *idle;
855         unsigned long long idle_count;
856
857         idle = &per_cpu(s390_idle, dev->id);
858         spin_lock(&idle->lock);
859         idle_count = idle->idle_count;
860         if (idle->idle_enter)
861                 idle_count++;
862         spin_unlock(&idle->lock);
863         return sprintf(buf, "%llu\n", idle_count);
864 }
865 static SYSDEV_ATTR(idle_count, 0444, show_idle_count, NULL);
866
867 static ssize_t show_idle_time(struct sys_device *dev,
868                                 struct sysdev_attribute *attr, char *buf)
869 {
870         struct s390_idle_data *idle;
871         unsigned long long now, idle_time, idle_enter;
872
873         idle = &per_cpu(s390_idle, dev->id);
874         spin_lock(&idle->lock);
875         now = get_clock();
876         idle_time = idle->idle_time;
877         idle_enter = idle->idle_enter;
878         if (idle_enter != 0ULL && idle_enter < now)
879                 idle_time += now - idle_enter;
880         spin_unlock(&idle->lock);
881         return sprintf(buf, "%llu\n", idle_time >> 12);
882 }
883 static SYSDEV_ATTR(idle_time_us, 0444, show_idle_time, NULL);
884
885 static struct attribute *cpu_online_attrs[] = {
886         &attr_capability.attr,
887         &attr_idle_count.attr,
888         &attr_idle_time_us.attr,
889         NULL,
890 };
891
892 static struct attribute_group cpu_online_attr_group = {
893         .attrs = cpu_online_attrs,
894 };
895
896 static int __cpuinit smp_cpu_notify(struct notifier_block *self,
897                                     unsigned long action, void *hcpu)
898 {
899         unsigned int cpu = (unsigned int)(long)hcpu;
900         struct cpu *c = &per_cpu(cpu_devices, cpu);
901         struct sys_device *s = &c->sysdev;
902         struct s390_idle_data *idle;
903
904         switch (action) {
905         case CPU_ONLINE:
906         case CPU_ONLINE_FROZEN:
907                 idle = &per_cpu(s390_idle, cpu);
908                 spin_lock_irq(&idle->lock);
909                 idle->idle_enter = 0;
910                 idle->idle_time = 0;
911                 idle->idle_count = 0;
912                 spin_unlock_irq(&idle->lock);
913                 if (sysfs_create_group(&s->kobj, &cpu_online_attr_group))
914                         return NOTIFY_BAD;
915                 break;
916         case CPU_DEAD:
917         case CPU_DEAD_FROZEN:
918                 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
919                 break;
920         }
921         return NOTIFY_OK;
922 }
923
924 static struct notifier_block __cpuinitdata smp_cpu_nb = {
925         .notifier_call = smp_cpu_notify,
926 };
927
928 static int __devinit smp_add_present_cpu(int cpu)
929 {
930         struct cpu *c = &per_cpu(cpu_devices, cpu);
931         struct sys_device *s = &c->sysdev;
932         int rc;
933
934         c->hotpluggable = 1;
935         rc = register_cpu(c, cpu);
936         if (rc)
937                 goto out;
938         rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
939         if (rc)
940                 goto out_cpu;
941         if (!cpu_online(cpu))
942                 goto out;
943         rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
944         if (!rc)
945                 return 0;
946         sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
947 out_cpu:
948 #ifdef CONFIG_HOTPLUG_CPU
949         unregister_cpu(c);
950 #endif
951 out:
952         return rc;
953 }
954
955 #ifdef CONFIG_HOTPLUG_CPU
956
957 int __ref smp_rescan_cpus(void)
958 {
959         cpumask_t newcpus;
960         int cpu;
961         int rc;
962
963         get_online_cpus();
964         mutex_lock(&smp_cpu_state_mutex);
965         newcpus = cpu_present_map;
966         rc = __smp_rescan_cpus();
967         if (rc)
968                 goto out;
969         cpus_andnot(newcpus, cpu_present_map, newcpus);
970         for_each_cpu_mask(cpu, newcpus) {
971                 rc = smp_add_present_cpu(cpu);
972                 if (rc)
973                         cpu_clear(cpu, cpu_present_map);
974         }
975         rc = 0;
976 out:
977         mutex_unlock(&smp_cpu_state_mutex);
978         put_online_cpus();
979         if (!cpus_empty(newcpus))
980                 topology_schedule_update();
981         return rc;
982 }
983
984 static ssize_t __ref rescan_store(struct sysdev_class *class, const char *buf,
985                                   size_t count)
986 {
987         int rc;
988
989         rc = smp_rescan_cpus();
990         return rc ? rc : count;
991 }
992 static SYSDEV_CLASS_ATTR(rescan, 0200, NULL, rescan_store);
993 #endif /* CONFIG_HOTPLUG_CPU */
994
995 static ssize_t dispatching_show(struct sysdev_class *class, char *buf)
996 {
997         ssize_t count;
998
999         mutex_lock(&smp_cpu_state_mutex);
1000         count = sprintf(buf, "%d\n", cpu_management);
1001         mutex_unlock(&smp_cpu_state_mutex);
1002         return count;
1003 }
1004
1005 static ssize_t dispatching_store(struct sysdev_class *dev, const char *buf,
1006                                  size_t count)
1007 {
1008         int val, rc;
1009         char delim;
1010
1011         if (sscanf(buf, "%d %c", &val, &delim) != 1)
1012                 return -EINVAL;
1013         if (val != 0 && val != 1)
1014                 return -EINVAL;
1015         rc = 0;
1016         get_online_cpus();
1017         mutex_lock(&smp_cpu_state_mutex);
1018         if (cpu_management == val)
1019                 goto out;
1020         rc = topology_set_cpu_management(val);
1021         if (!rc)
1022                 cpu_management = val;
1023 out:
1024         mutex_unlock(&smp_cpu_state_mutex);
1025         put_online_cpus();
1026         return rc ? rc : count;
1027 }
1028 static SYSDEV_CLASS_ATTR(dispatching, 0644, dispatching_show,
1029                          dispatching_store);
1030
1031 static int __init topology_init(void)
1032 {
1033         int cpu;
1034         int rc;
1035
1036         register_cpu_notifier(&smp_cpu_nb);
1037
1038 #ifdef CONFIG_HOTPLUG_CPU
1039         rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_rescan);
1040         if (rc)
1041                 return rc;
1042 #endif
1043         rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_dispatching);
1044         if (rc)
1045                 return rc;
1046         for_each_present_cpu(cpu) {
1047                 rc = smp_add_present_cpu(cpu);
1048                 if (rc)
1049                         return rc;
1050         }
1051         return 0;
1052 }
1053 subsys_initcall(topology_init);