[S390] Cleanup struct _lowcore usage and defines.
[linux-2.6.git] / arch / s390 / kernel / smp.c
1 /*
2  *  arch/s390/kernel/smp.c
3  *
4  *    Copyright IBM Corp. 1999, 2009
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/asm-offsets.h>
40 #include <asm/ipl.h>
41 #include <asm/setup.h>
42 #include <asm/sigp.h>
43 #include <asm/pgalloc.h>
44 #include <asm/irq.h>
45 #include <asm/s390_ext.h>
46 #include <asm/cpcmd.h>
47 #include <asm/tlbflush.h>
48 #include <asm/timer.h>
49 #include <asm/lowcore.h>
50 #include <asm/sclp.h>
51 #include <asm/cputime.h>
52 #include <asm/vdso.h>
53 #include <asm/cpu.h>
54 #include "entry.h"
55
56 /* logical cpu to cpu address */
57 unsigned short __cpu_logical_map[NR_CPUS];
58
59 static struct task_struct *current_set[NR_CPUS];
60
61 static u8 smp_cpu_type;
62 static int smp_use_sigp_detection;
63
64 enum s390_cpu_state {
65         CPU_STATE_STANDBY,
66         CPU_STATE_CONFIGURED,
67 };
68
69 DEFINE_MUTEX(smp_cpu_state_mutex);
70 int smp_cpu_polarization[NR_CPUS];
71 static int smp_cpu_state[NR_CPUS];
72 static int cpu_management;
73
74 static DEFINE_PER_CPU(struct cpu, cpu_devices);
75
76 static void smp_ext_bitcall(int, int);
77
78 static int raw_cpu_stopped(int cpu)
79 {
80         u32 status;
81
82         switch (raw_sigp_ps(&status, 0, cpu, sigp_sense)) {
83         case sigp_status_stored:
84                 /* Check for stopped and check stop state */
85                 if (status & 0x50)
86                         return 1;
87                 break;
88         default:
89                 break;
90         }
91         return 0;
92 }
93
94 static inline int cpu_stopped(int cpu)
95 {
96         return raw_cpu_stopped(cpu_logical_map(cpu));
97 }
98
99 void smp_switch_to_ipl_cpu(void (*func)(void *), void *data)
100 {
101         struct _lowcore *lc, *current_lc;
102         struct stack_frame *sf;
103         struct pt_regs *regs;
104         unsigned long sp;
105
106         if (smp_processor_id() == 0)
107                 func(data);
108         __load_psw_mask(PSW_BASE_BITS | PSW_DEFAULT_KEY);
109         /* Disable lowcore protection */
110         __ctl_clear_bit(0, 28);
111         current_lc = lowcore_ptr[smp_processor_id()];
112         lc = lowcore_ptr[0];
113         if (!lc)
114                 lc = current_lc;
115         lc->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
116         lc->restart_psw.addr = PSW_ADDR_AMODE | (unsigned long) smp_restart_cpu;
117         if (!cpu_online(0))
118                 smp_switch_to_cpu(func, data, 0, stap(), __cpu_logical_map[0]);
119         while (sigp(0, sigp_stop_and_store_status) == sigp_busy)
120                 cpu_relax();
121         sp = lc->panic_stack;
122         sp -= sizeof(struct pt_regs);
123         regs = (struct pt_regs *) sp;
124         memcpy(&regs->gprs, &current_lc->gpregs_save_area, sizeof(regs->gprs));
125         regs->psw = lc->psw_save_area;
126         sp -= STACK_FRAME_OVERHEAD;
127         sf = (struct stack_frame *) sp;
128         sf->back_chain = regs->gprs[15];
129         smp_switch_to_cpu(func, data, sp, stap(), __cpu_logical_map[0]);
130 }
131
132 void smp_send_stop(void)
133 {
134         int cpu, rc;
135
136         /* Disable all interrupts/machine checks */
137         __load_psw_mask(psw_kernel_bits & ~PSW_MASK_MCHECK);
138         trace_hardirqs_off();
139
140         /* stop all processors */
141         for_each_online_cpu(cpu) {
142                 if (cpu == smp_processor_id())
143                         continue;
144                 do {
145                         rc = sigp(cpu, sigp_stop);
146                 } while (rc == sigp_busy);
147
148                 while (!cpu_stopped(cpu))
149                         cpu_relax();
150         }
151 }
152
153 /*
154  * This is the main routine where commands issued by other
155  * cpus are handled.
156  */
157
158 static void do_ext_call_interrupt(__u16 code)
159 {
160         unsigned long bits;
161
162         /*
163          * handle bit signal external calls
164          *
165          * For the ec_schedule signal we have to do nothing. All the work
166          * is done automatically when we return from the interrupt.
167          */
168         bits = xchg(&S390_lowcore.ext_call_fast, 0);
169
170         if (test_bit(ec_call_function, &bits))
171                 generic_smp_call_function_interrupt();
172
173         if (test_bit(ec_call_function_single, &bits))
174                 generic_smp_call_function_single_interrupt();
175 }
176
177 /*
178  * Send an external call sigp to another cpu and return without waiting
179  * for its completion.
180  */
181 static void smp_ext_bitcall(int cpu, int sig)
182 {
183         /*
184          * Set signaling bit in lowcore of target cpu and kick it
185          */
186         set_bit(sig, (unsigned long *) &lowcore_ptr[cpu]->ext_call_fast);
187         while (sigp(cpu, sigp_emergency_signal) == sigp_busy)
188                 udelay(10);
189 }
190
191 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
192 {
193         int cpu;
194
195         for_each_cpu(cpu, mask)
196                 smp_ext_bitcall(cpu, ec_call_function);
197 }
198
199 void arch_send_call_function_single_ipi(int cpu)
200 {
201         smp_ext_bitcall(cpu, ec_call_function_single);
202 }
203
204 #ifndef CONFIG_64BIT
205 /*
206  * this function sends a 'purge tlb' signal to another CPU.
207  */
208 static void smp_ptlb_callback(void *info)
209 {
210         __tlb_flush_local();
211 }
212
213 void smp_ptlb_all(void)
214 {
215         on_each_cpu(smp_ptlb_callback, NULL, 1);
216 }
217 EXPORT_SYMBOL(smp_ptlb_all);
218 #endif /* ! CONFIG_64BIT */
219
220 /*
221  * this function sends a 'reschedule' IPI to another CPU.
222  * it goes straight through and wastes no time serializing
223  * anything. Worst case is that we lose a reschedule ...
224  */
225 void smp_send_reschedule(int cpu)
226 {
227         smp_ext_bitcall(cpu, ec_schedule);
228 }
229
230 /*
231  * parameter area for the set/clear control bit callbacks
232  */
233 struct ec_creg_mask_parms {
234         unsigned long orvals[16];
235         unsigned long andvals[16];
236 };
237
238 /*
239  * callback for setting/clearing control bits
240  */
241 static void smp_ctl_bit_callback(void *info)
242 {
243         struct ec_creg_mask_parms *pp = info;
244         unsigned long cregs[16];
245         int i;
246
247         __ctl_store(cregs, 0, 15);
248         for (i = 0; i <= 15; i++)
249                 cregs[i] = (cregs[i] & pp->andvals[i]) | pp->orvals[i];
250         __ctl_load(cregs, 0, 15);
251 }
252
253 /*
254  * Set a bit in a control register of all cpus
255  */
256 void smp_ctl_set_bit(int cr, int bit)
257 {
258         struct ec_creg_mask_parms parms;
259
260         memset(&parms.orvals, 0, sizeof(parms.orvals));
261         memset(&parms.andvals, 0xff, sizeof(parms.andvals));
262         parms.orvals[cr] = 1 << bit;
263         on_each_cpu(smp_ctl_bit_callback, &parms, 1);
264 }
265 EXPORT_SYMBOL(smp_ctl_set_bit);
266
267 /*
268  * Clear a bit in a control register of all cpus
269  */
270 void smp_ctl_clear_bit(int cr, int bit)
271 {
272         struct ec_creg_mask_parms parms;
273
274         memset(&parms.orvals, 0, sizeof(parms.orvals));
275         memset(&parms.andvals, 0xff, sizeof(parms.andvals));
276         parms.andvals[cr] = ~(1L << bit);
277         on_each_cpu(smp_ctl_bit_callback, &parms, 1);
278 }
279 EXPORT_SYMBOL(smp_ctl_clear_bit);
280
281 #ifdef CONFIG_ZFCPDUMP
282
283 static void __init smp_get_save_area(unsigned int cpu, unsigned int phy_cpu)
284 {
285         if (ipl_info.type != IPL_TYPE_FCP_DUMP)
286                 return;
287         if (cpu >= NR_CPUS) {
288                 pr_warning("CPU %i exceeds the maximum %i and is excluded from "
289                            "the dump\n", cpu, NR_CPUS - 1);
290                 return;
291         }
292         zfcpdump_save_areas[cpu] = kmalloc(sizeof(struct save_area), GFP_KERNEL);
293         while (raw_sigp(phy_cpu, sigp_stop_and_store_status) == sigp_busy)
294                 cpu_relax();
295         memcpy(zfcpdump_save_areas[cpu],
296                (void *)(unsigned long) store_prefix() + SAVE_AREA_BASE,
297                sizeof(struct save_area));
298 }
299
300 struct save_area *zfcpdump_save_areas[NR_CPUS + 1];
301 EXPORT_SYMBOL_GPL(zfcpdump_save_areas);
302
303 #else
304
305 static inline void smp_get_save_area(unsigned int cpu, unsigned int phy_cpu) { }
306
307 #endif /* CONFIG_ZFCPDUMP */
308
309 static int cpu_known(int cpu_id)
310 {
311         int cpu;
312
313         for_each_present_cpu(cpu) {
314                 if (__cpu_logical_map[cpu] == cpu_id)
315                         return 1;
316         }
317         return 0;
318 }
319
320 static int smp_rescan_cpus_sigp(cpumask_t avail)
321 {
322         int cpu_id, logical_cpu;
323
324         logical_cpu = cpumask_first(&avail);
325         if (logical_cpu >= nr_cpu_ids)
326                 return 0;
327         for (cpu_id = 0; cpu_id <= MAX_CPU_ADDRESS; cpu_id++) {
328                 if (cpu_known(cpu_id))
329                         continue;
330                 __cpu_logical_map[logical_cpu] = cpu_id;
331                 smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN;
332                 if (!cpu_stopped(logical_cpu))
333                         continue;
334                 cpu_set(logical_cpu, cpu_present_map);
335                 smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
336                 logical_cpu = cpumask_next(logical_cpu, &avail);
337                 if (logical_cpu >= nr_cpu_ids)
338                         break;
339         }
340         return 0;
341 }
342
343 static int smp_rescan_cpus_sclp(cpumask_t avail)
344 {
345         struct sclp_cpu_info *info;
346         int cpu_id, logical_cpu, cpu;
347         int rc;
348
349         logical_cpu = cpumask_first(&avail);
350         if (logical_cpu >= nr_cpu_ids)
351                 return 0;
352         info = kmalloc(sizeof(*info), GFP_KERNEL);
353         if (!info)
354                 return -ENOMEM;
355         rc = sclp_get_cpu_info(info);
356         if (rc)
357                 goto out;
358         for (cpu = 0; cpu < info->combined; cpu++) {
359                 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
360                         continue;
361                 cpu_id = info->cpu[cpu].address;
362                 if (cpu_known(cpu_id))
363                         continue;
364                 __cpu_logical_map[logical_cpu] = cpu_id;
365                 smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN;
366                 cpu_set(logical_cpu, cpu_present_map);
367                 if (cpu >= info->configured)
368                         smp_cpu_state[logical_cpu] = CPU_STATE_STANDBY;
369                 else
370                         smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
371                 logical_cpu = cpumask_next(logical_cpu, &avail);
372                 if (logical_cpu >= nr_cpu_ids)
373                         break;
374         }
375 out:
376         kfree(info);
377         return rc;
378 }
379
380 static int __smp_rescan_cpus(void)
381 {
382         cpumask_t avail;
383
384         cpus_xor(avail, cpu_possible_map, cpu_present_map);
385         if (smp_use_sigp_detection)
386                 return smp_rescan_cpus_sigp(avail);
387         else
388                 return smp_rescan_cpus_sclp(avail);
389 }
390
391 static void __init smp_detect_cpus(void)
392 {
393         unsigned int cpu, c_cpus, s_cpus;
394         struct sclp_cpu_info *info;
395         u16 boot_cpu_addr, cpu_addr;
396
397         c_cpus = 1;
398         s_cpus = 0;
399         boot_cpu_addr = __cpu_logical_map[0];
400         info = kmalloc(sizeof(*info), GFP_KERNEL);
401         if (!info)
402                 panic("smp_detect_cpus failed to allocate memory\n");
403         /* Use sigp detection algorithm if sclp doesn't work. */
404         if (sclp_get_cpu_info(info)) {
405                 smp_use_sigp_detection = 1;
406                 for (cpu = 0; cpu <= MAX_CPU_ADDRESS; cpu++) {
407                         if (cpu == boot_cpu_addr)
408                                 continue;
409                         if (!raw_cpu_stopped(cpu))
410                                 continue;
411                         smp_get_save_area(c_cpus, cpu);
412                         c_cpus++;
413                 }
414                 goto out;
415         }
416
417         if (info->has_cpu_type) {
418                 for (cpu = 0; cpu < info->combined; cpu++) {
419                         if (info->cpu[cpu].address == boot_cpu_addr) {
420                                 smp_cpu_type = info->cpu[cpu].type;
421                                 break;
422                         }
423                 }
424         }
425
426         for (cpu = 0; cpu < info->combined; cpu++) {
427                 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
428                         continue;
429                 cpu_addr = info->cpu[cpu].address;
430                 if (cpu_addr == boot_cpu_addr)
431                         continue;
432                 if (!raw_cpu_stopped(cpu_addr)) {
433                         s_cpus++;
434                         continue;
435                 }
436                 smp_get_save_area(c_cpus, cpu_addr);
437                 c_cpus++;
438         }
439 out:
440         kfree(info);
441         pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
442         get_online_cpus();
443         __smp_rescan_cpus();
444         put_online_cpus();
445 }
446
447 /*
448  *      Activate a secondary processor.
449  */
450 int __cpuinit start_secondary(void *cpuvoid)
451 {
452         /* Setup the cpu */
453         cpu_init();
454         preempt_disable();
455         /* Enable TOD clock interrupts on the secondary cpu. */
456         init_cpu_timer();
457         /* Enable cpu timer interrupts on the secondary cpu. */
458         init_cpu_vtimer();
459         /* Enable pfault pseudo page faults on this cpu. */
460         pfault_init();
461
462         /* call cpu notifiers */
463         notify_cpu_starting(smp_processor_id());
464         /* Mark this cpu as online */
465         ipi_call_lock();
466         cpu_set(smp_processor_id(), cpu_online_map);
467         ipi_call_unlock();
468         /* Switch on interrupts */
469         local_irq_enable();
470         /* Print info about this processor */
471         print_cpu_info();
472         /* cpu_idle will call schedule for us */
473         cpu_idle();
474         return 0;
475 }
476
477 static void __init smp_create_idle(unsigned int cpu)
478 {
479         struct task_struct *p;
480
481         /*
482          *  don't care about the psw and regs settings since we'll never
483          *  reschedule the forked task.
484          */
485         p = fork_idle(cpu);
486         if (IS_ERR(p))
487                 panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p));
488         current_set[cpu] = p;
489 }
490
491 static int __cpuinit smp_alloc_lowcore(int cpu)
492 {
493         unsigned long async_stack, panic_stack;
494         struct _lowcore *lowcore;
495
496         lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
497         if (!lowcore)
498                 return -ENOMEM;
499         async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
500         panic_stack = __get_free_page(GFP_KERNEL);
501         if (!panic_stack || !async_stack)
502                 goto out;
503         memcpy(lowcore, &S390_lowcore, 512);
504         memset((char *)lowcore + 512, 0, sizeof(*lowcore) - 512);
505         lowcore->async_stack = async_stack + ASYNC_SIZE;
506         lowcore->panic_stack = panic_stack + PAGE_SIZE;
507
508 #ifndef CONFIG_64BIT
509         if (MACHINE_HAS_IEEE) {
510                 unsigned long save_area;
511
512                 save_area = get_zeroed_page(GFP_KERNEL);
513                 if (!save_area)
514                         goto out;
515                 lowcore->extended_save_area_addr = (u32) save_area;
516         }
517 #else
518         if (vdso_alloc_per_cpu(cpu, lowcore))
519                 goto out;
520 #endif
521         lowcore_ptr[cpu] = lowcore;
522         return 0;
523
524 out:
525         free_page(panic_stack);
526         free_pages(async_stack, ASYNC_ORDER);
527         free_pages((unsigned long) lowcore, LC_ORDER);
528         return -ENOMEM;
529 }
530
531 static void smp_free_lowcore(int cpu)
532 {
533         struct _lowcore *lowcore;
534
535         lowcore = lowcore_ptr[cpu];
536 #ifndef CONFIG_64BIT
537         if (MACHINE_HAS_IEEE)
538                 free_page((unsigned long) lowcore->extended_save_area_addr);
539 #else
540         vdso_free_per_cpu(cpu, lowcore);
541 #endif
542         free_page(lowcore->panic_stack - PAGE_SIZE);
543         free_pages(lowcore->async_stack - ASYNC_SIZE, ASYNC_ORDER);
544         free_pages((unsigned long) lowcore, LC_ORDER);
545         lowcore_ptr[cpu] = NULL;
546 }
547
548 /* Upping and downing of CPUs */
549 int __cpuinit __cpu_up(unsigned int cpu)
550 {
551         struct _lowcore *cpu_lowcore;
552         struct task_struct *idle;
553         struct stack_frame *sf;
554         u32 lowcore;
555         int ccode;
556
557         if (smp_cpu_state[cpu] != CPU_STATE_CONFIGURED)
558                 return -EIO;
559         if (smp_alloc_lowcore(cpu))
560                 return -ENOMEM;
561         do {
562                 ccode = sigp(cpu, sigp_initial_cpu_reset);
563                 if (ccode == sigp_busy)
564                         udelay(10);
565                 if (ccode == sigp_not_operational)
566                         goto err_out;
567         } while (ccode == sigp_busy);
568
569         lowcore = (u32)(unsigned long)lowcore_ptr[cpu];
570         while (sigp_p(lowcore, cpu, sigp_set_prefix) == sigp_busy)
571                 udelay(10);
572
573         idle = current_set[cpu];
574         cpu_lowcore = lowcore_ptr[cpu];
575         cpu_lowcore->kernel_stack = (unsigned long)
576                 task_stack_page(idle) + THREAD_SIZE;
577         cpu_lowcore->thread_info = (unsigned long) task_thread_info(idle);
578         sf = (struct stack_frame *) (cpu_lowcore->kernel_stack
579                                      - sizeof(struct pt_regs)
580                                      - sizeof(struct stack_frame));
581         memset(sf, 0, sizeof(struct stack_frame));
582         sf->gprs[9] = (unsigned long) sf;
583         cpu_lowcore->save_area[15] = (unsigned long) sf;
584         __ctl_store(cpu_lowcore->cregs_save_area, 0, 15);
585         asm volatile(
586                 "       stam    0,15,0(%0)"
587                 : : "a" (&cpu_lowcore->access_regs_save_area) : "memory");
588         cpu_lowcore->percpu_offset = __per_cpu_offset[cpu];
589         cpu_lowcore->current_task = (unsigned long) idle;
590         cpu_lowcore->cpu_nr = cpu;
591         cpu_lowcore->kernel_asce = S390_lowcore.kernel_asce;
592         cpu_lowcore->machine_flags = S390_lowcore.machine_flags;
593         cpu_lowcore->ftrace_func = S390_lowcore.ftrace_func;
594         eieio();
595
596         while (sigp(cpu, sigp_restart) == sigp_busy)
597                 udelay(10);
598
599         while (!cpu_online(cpu))
600                 cpu_relax();
601         return 0;
602
603 err_out:
604         smp_free_lowcore(cpu);
605         return -EIO;
606 }
607
608 static int __init setup_possible_cpus(char *s)
609 {
610         int pcpus, cpu;
611
612         pcpus = simple_strtoul(s, NULL, 0);
613         init_cpu_possible(cpumask_of(0));
614         for (cpu = 1; cpu < pcpus && cpu < nr_cpu_ids; cpu++)
615                 set_cpu_possible(cpu, true);
616         return 0;
617 }
618 early_param("possible_cpus", setup_possible_cpus);
619
620 #ifdef CONFIG_HOTPLUG_CPU
621
622 int __cpu_disable(void)
623 {
624         struct ec_creg_mask_parms cr_parms;
625         int cpu = smp_processor_id();
626
627         cpu_clear(cpu, cpu_online_map);
628
629         /* Disable pfault pseudo page faults on this cpu. */
630         pfault_fini();
631
632         memset(&cr_parms.orvals, 0, sizeof(cr_parms.orvals));
633         memset(&cr_parms.andvals, 0xff, sizeof(cr_parms.andvals));
634
635         /* disable all external interrupts */
636         cr_parms.orvals[0] = 0;
637         cr_parms.andvals[0] = ~(1 << 15 | 1 << 14 | 1 << 13 | 1 << 12 |
638                                 1 << 11 | 1 << 10 | 1 <<  6 | 1 <<  4);
639         /* disable all I/O interrupts */
640         cr_parms.orvals[6] = 0;
641         cr_parms.andvals[6] = ~(1 << 31 | 1 << 30 | 1 << 29 | 1 << 28 |
642                                 1 << 27 | 1 << 26 | 1 << 25 | 1 << 24);
643         /* disable most machine checks */
644         cr_parms.orvals[14] = 0;
645         cr_parms.andvals[14] = ~(1 << 28 | 1 << 27 | 1 << 26 |
646                                  1 << 25 | 1 << 24);
647
648         smp_ctl_bit_callback(&cr_parms);
649
650         return 0;
651 }
652
653 void __cpu_die(unsigned int cpu)
654 {
655         /* Wait until target cpu is down */
656         while (!cpu_stopped(cpu))
657                 cpu_relax();
658         while (sigp_p(0, cpu, sigp_set_prefix) == sigp_busy)
659                 udelay(10);
660         smp_free_lowcore(cpu);
661         pr_info("Processor %d stopped\n", cpu);
662 }
663
664 void cpu_die(void)
665 {
666         idle_task_exit();
667         while (sigp(smp_processor_id(), sigp_stop) == sigp_busy)
668                 cpu_relax();
669         for (;;);
670 }
671
672 #endif /* CONFIG_HOTPLUG_CPU */
673
674 void __init smp_prepare_cpus(unsigned int max_cpus)
675 {
676 #ifndef CONFIG_64BIT
677         unsigned long save_area = 0;
678 #endif
679         unsigned long async_stack, panic_stack;
680         struct _lowcore *lowcore;
681         unsigned int cpu;
682
683         smp_detect_cpus();
684
685         /* request the 0x1201 emergency signal external interrupt */
686         if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0)
687                 panic("Couldn't request external interrupt 0x1201");
688         print_cpu_info();
689
690         /* Reallocate current lowcore, but keep its contents. */
691         lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
692         panic_stack = __get_free_page(GFP_KERNEL);
693         async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
694         BUG_ON(!lowcore || !panic_stack || !async_stack);
695 #ifndef CONFIG_64BIT
696         if (MACHINE_HAS_IEEE)
697                 save_area = get_zeroed_page(GFP_KERNEL);
698 #endif
699         local_irq_disable();
700         local_mcck_disable();
701         lowcore_ptr[smp_processor_id()] = lowcore;
702         *lowcore = S390_lowcore;
703         lowcore->panic_stack = panic_stack + PAGE_SIZE;
704         lowcore->async_stack = async_stack + ASYNC_SIZE;
705 #ifndef CONFIG_64BIT
706         if (MACHINE_HAS_IEEE)
707                 lowcore->extended_save_area_addr = (u32) save_area;
708 #endif
709         set_prefix((u32)(unsigned long) lowcore);
710         local_mcck_enable();
711         local_irq_enable();
712 #ifdef CONFIG_64BIT
713         if (vdso_alloc_per_cpu(smp_processor_id(), &S390_lowcore))
714                 BUG();
715 #endif
716         for_each_possible_cpu(cpu)
717                 if (cpu != smp_processor_id())
718                         smp_create_idle(cpu);
719 }
720
721 void __init smp_prepare_boot_cpu(void)
722 {
723         BUG_ON(smp_processor_id() != 0);
724
725         current_thread_info()->cpu = 0;
726         cpu_set(0, cpu_present_map);
727         cpu_set(0, cpu_online_map);
728         S390_lowcore.percpu_offset = __per_cpu_offset[0];
729         current_set[0] = current;
730         smp_cpu_state[0] = CPU_STATE_CONFIGURED;
731         smp_cpu_polarization[0] = POLARIZATION_UNKNWN;
732 }
733
734 void __init smp_cpus_done(unsigned int max_cpus)
735 {
736 }
737
738 void __init smp_setup_processor_id(void)
739 {
740         S390_lowcore.cpu_nr = 0;
741         __cpu_logical_map[0] = stap();
742 }
743
744 /*
745  * the frequency of the profiling timer can be changed
746  * by writing a multiplier value into /proc/profile.
747  *
748  * usually you want to run this on all CPUs ;)
749  */
750 int setup_profiling_timer(unsigned int multiplier)
751 {
752         return 0;
753 }
754
755 #ifdef CONFIG_HOTPLUG_CPU
756 static ssize_t cpu_configure_show(struct sys_device *dev,
757                                 struct sysdev_attribute *attr, char *buf)
758 {
759         ssize_t count;
760
761         mutex_lock(&smp_cpu_state_mutex);
762         count = sprintf(buf, "%d\n", smp_cpu_state[dev->id]);
763         mutex_unlock(&smp_cpu_state_mutex);
764         return count;
765 }
766
767 static ssize_t cpu_configure_store(struct sys_device *dev,
768                                   struct sysdev_attribute *attr,
769                                   const char *buf, size_t count)
770 {
771         int cpu = dev->id;
772         int val, rc;
773         char delim;
774
775         if (sscanf(buf, "%d %c", &val, &delim) != 1)
776                 return -EINVAL;
777         if (val != 0 && val != 1)
778                 return -EINVAL;
779
780         get_online_cpus();
781         mutex_lock(&smp_cpu_state_mutex);
782         rc = -EBUSY;
783         /* disallow configuration changes of online cpus and cpu 0 */
784         if (cpu_online(cpu) || cpu == 0)
785                 goto out;
786         rc = 0;
787         switch (val) {
788         case 0:
789                 if (smp_cpu_state[cpu] == CPU_STATE_CONFIGURED) {
790                         rc = sclp_cpu_deconfigure(__cpu_logical_map[cpu]);
791                         if (!rc) {
792                                 smp_cpu_state[cpu] = CPU_STATE_STANDBY;
793                                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
794                         }
795                 }
796                 break;
797         case 1:
798                 if (smp_cpu_state[cpu] == CPU_STATE_STANDBY) {
799                         rc = sclp_cpu_configure(__cpu_logical_map[cpu]);
800                         if (!rc) {
801                                 smp_cpu_state[cpu] = CPU_STATE_CONFIGURED;
802                                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
803                         }
804                 }
805                 break;
806         default:
807                 break;
808         }
809 out:
810         mutex_unlock(&smp_cpu_state_mutex);
811         put_online_cpus();
812         return rc ? rc : count;
813 }
814 static SYSDEV_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
815 #endif /* CONFIG_HOTPLUG_CPU */
816
817 static ssize_t cpu_polarization_show(struct sys_device *dev,
818                                      struct sysdev_attribute *attr, char *buf)
819 {
820         int cpu = dev->id;
821         ssize_t count;
822
823         mutex_lock(&smp_cpu_state_mutex);
824         switch (smp_cpu_polarization[cpu]) {
825         case POLARIZATION_HRZ:
826                 count = sprintf(buf, "horizontal\n");
827                 break;
828         case POLARIZATION_VL:
829                 count = sprintf(buf, "vertical:low\n");
830                 break;
831         case POLARIZATION_VM:
832                 count = sprintf(buf, "vertical:medium\n");
833                 break;
834         case POLARIZATION_VH:
835                 count = sprintf(buf, "vertical:high\n");
836                 break;
837         default:
838                 count = sprintf(buf, "unknown\n");
839                 break;
840         }
841         mutex_unlock(&smp_cpu_state_mutex);
842         return count;
843 }
844 static SYSDEV_ATTR(polarization, 0444, cpu_polarization_show, NULL);
845
846 static ssize_t show_cpu_address(struct sys_device *dev,
847                                 struct sysdev_attribute *attr, char *buf)
848 {
849         return sprintf(buf, "%d\n", __cpu_logical_map[dev->id]);
850 }
851 static SYSDEV_ATTR(address, 0444, show_cpu_address, NULL);
852
853
854 static struct attribute *cpu_common_attrs[] = {
855 #ifdef CONFIG_HOTPLUG_CPU
856         &attr_configure.attr,
857 #endif
858         &attr_address.attr,
859         &attr_polarization.attr,
860         NULL,
861 };
862
863 static struct attribute_group cpu_common_attr_group = {
864         .attrs = cpu_common_attrs,
865 };
866
867 static ssize_t show_capability(struct sys_device *dev,
868                                 struct sysdev_attribute *attr, char *buf)
869 {
870         unsigned int capability;
871         int rc;
872
873         rc = get_cpu_capability(&capability);
874         if (rc)
875                 return rc;
876         return sprintf(buf, "%u\n", capability);
877 }
878 static SYSDEV_ATTR(capability, 0444, show_capability, NULL);
879
880 static ssize_t show_idle_count(struct sys_device *dev,
881                                 struct sysdev_attribute *attr, char *buf)
882 {
883         struct s390_idle_data *idle;
884         unsigned long long idle_count;
885         unsigned int sequence;
886
887         idle = &per_cpu(s390_idle, dev->id);
888 repeat:
889         sequence = idle->sequence;
890         smp_rmb();
891         if (sequence & 1)
892                 goto repeat;
893         idle_count = idle->idle_count;
894         if (idle->idle_enter)
895                 idle_count++;
896         smp_rmb();
897         if (idle->sequence != sequence)
898                 goto repeat;
899         return sprintf(buf, "%llu\n", idle_count);
900 }
901 static SYSDEV_ATTR(idle_count, 0444, show_idle_count, NULL);
902
903 static ssize_t show_idle_time(struct sys_device *dev,
904                                 struct sysdev_attribute *attr, char *buf)
905 {
906         struct s390_idle_data *idle;
907         unsigned long long now, idle_time, idle_enter;
908         unsigned int sequence;
909
910         idle = &per_cpu(s390_idle, dev->id);
911         now = get_clock();
912 repeat:
913         sequence = idle->sequence;
914         smp_rmb();
915         if (sequence & 1)
916                 goto repeat;
917         idle_time = idle->idle_time;
918         idle_enter = idle->idle_enter;
919         if (idle_enter != 0ULL && idle_enter < now)
920                 idle_time += now - idle_enter;
921         smp_rmb();
922         if (idle->sequence != sequence)
923                 goto repeat;
924         return sprintf(buf, "%llu\n", idle_time >> 12);
925 }
926 static SYSDEV_ATTR(idle_time_us, 0444, show_idle_time, NULL);
927
928 static struct attribute *cpu_online_attrs[] = {
929         &attr_capability.attr,
930         &attr_idle_count.attr,
931         &attr_idle_time_us.attr,
932         NULL,
933 };
934
935 static struct attribute_group cpu_online_attr_group = {
936         .attrs = cpu_online_attrs,
937 };
938
939 static int __cpuinit smp_cpu_notify(struct notifier_block *self,
940                                     unsigned long action, void *hcpu)
941 {
942         unsigned int cpu = (unsigned int)(long)hcpu;
943         struct cpu *c = &per_cpu(cpu_devices, cpu);
944         struct sys_device *s = &c->sysdev;
945         struct s390_idle_data *idle;
946
947         switch (action) {
948         case CPU_ONLINE:
949         case CPU_ONLINE_FROZEN:
950                 idle = &per_cpu(s390_idle, cpu);
951                 memset(idle, 0, sizeof(struct s390_idle_data));
952                 if (sysfs_create_group(&s->kobj, &cpu_online_attr_group))
953                         return NOTIFY_BAD;
954                 break;
955         case CPU_DEAD:
956         case CPU_DEAD_FROZEN:
957                 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
958                 break;
959         }
960         return NOTIFY_OK;
961 }
962
963 static struct notifier_block __cpuinitdata smp_cpu_nb = {
964         .notifier_call = smp_cpu_notify,
965 };
966
967 static int __devinit smp_add_present_cpu(int cpu)
968 {
969         struct cpu *c = &per_cpu(cpu_devices, cpu);
970         struct sys_device *s = &c->sysdev;
971         int rc;
972
973         c->hotpluggable = 1;
974         rc = register_cpu(c, cpu);
975         if (rc)
976                 goto out;
977         rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
978         if (rc)
979                 goto out_cpu;
980         if (!cpu_online(cpu))
981                 goto out;
982         rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
983         if (!rc)
984                 return 0;
985         sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
986 out_cpu:
987 #ifdef CONFIG_HOTPLUG_CPU
988         unregister_cpu(c);
989 #endif
990 out:
991         return rc;
992 }
993
994 #ifdef CONFIG_HOTPLUG_CPU
995
996 int __ref smp_rescan_cpus(void)
997 {
998         cpumask_t newcpus;
999         int cpu;
1000         int rc;
1001
1002         get_online_cpus();
1003         mutex_lock(&smp_cpu_state_mutex);
1004         newcpus = cpu_present_map;
1005         rc = __smp_rescan_cpus();
1006         if (rc)
1007                 goto out;
1008         cpus_andnot(newcpus, cpu_present_map, newcpus);
1009         for_each_cpu_mask(cpu, newcpus) {
1010                 rc = smp_add_present_cpu(cpu);
1011                 if (rc)
1012                         cpu_clear(cpu, cpu_present_map);
1013         }
1014         rc = 0;
1015 out:
1016         mutex_unlock(&smp_cpu_state_mutex);
1017         put_online_cpus();
1018         if (!cpus_empty(newcpus))
1019                 topology_schedule_update();
1020         return rc;
1021 }
1022
1023 static ssize_t __ref rescan_store(struct sysdev_class *class, const char *buf,
1024                                   size_t count)
1025 {
1026         int rc;
1027
1028         rc = smp_rescan_cpus();
1029         return rc ? rc : count;
1030 }
1031 static SYSDEV_CLASS_ATTR(rescan, 0200, NULL, rescan_store);
1032 #endif /* CONFIG_HOTPLUG_CPU */
1033
1034 static ssize_t dispatching_show(struct sysdev_class *class, char *buf)
1035 {
1036         ssize_t count;
1037
1038         mutex_lock(&smp_cpu_state_mutex);
1039         count = sprintf(buf, "%d\n", cpu_management);
1040         mutex_unlock(&smp_cpu_state_mutex);
1041         return count;
1042 }
1043
1044 static ssize_t dispatching_store(struct sysdev_class *dev, const char *buf,
1045                                  size_t count)
1046 {
1047         int val, rc;
1048         char delim;
1049
1050         if (sscanf(buf, "%d %c", &val, &delim) != 1)
1051                 return -EINVAL;
1052         if (val != 0 && val != 1)
1053                 return -EINVAL;
1054         rc = 0;
1055         get_online_cpus();
1056         mutex_lock(&smp_cpu_state_mutex);
1057         if (cpu_management == val)
1058                 goto out;
1059         rc = topology_set_cpu_management(val);
1060         if (!rc)
1061                 cpu_management = val;
1062 out:
1063         mutex_unlock(&smp_cpu_state_mutex);
1064         put_online_cpus();
1065         return rc ? rc : count;
1066 }
1067 static SYSDEV_CLASS_ATTR(dispatching, 0644, dispatching_show,
1068                          dispatching_store);
1069
1070 static int __init topology_init(void)
1071 {
1072         int cpu;
1073         int rc;
1074
1075         register_cpu_notifier(&smp_cpu_nb);
1076
1077 #ifdef CONFIG_HOTPLUG_CPU
1078         rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_rescan);
1079         if (rc)
1080                 return rc;
1081 #endif
1082         rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_dispatching);
1083         if (rc)
1084                 return rc;
1085         for_each_present_cpu(cpu) {
1086                 rc = smp_add_present_cpu(cpu);
1087                 if (rc)
1088                         return rc;
1089         }
1090         return 0;
1091 }
1092 subsys_initcall(topology_init);