Merge branches 'topic/fix/misc' and 'topic/fix/asoc' into for-linus
[linux-2.6] / arch / s390 / kernel / smp.c
1 /*
2  *  arch/s390/kernel/smp.c
3  *
4  *    Copyright IBM Corp. 1999,2007
5  *    Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
6  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
7  *               Heiko Carstens (heiko.carstens@de.ibm.com)
8  *
9  *  based on other smp stuff by
10  *    (c) 1995 Alan Cox, CymruNET Ltd  <alan@cymru.net>
11  *    (c) 1998 Ingo Molnar
12  *
13  * We work with logical cpu numbering everywhere we can. The only
14  * functions using the real cpu address (got from STAP) are the sigp
15  * functions. For all other functions we use the identity mapping.
16  * That means that cpu_number_map[i] == i for every cpu. cpu_number_map is
17  * used e.g. to find the idle task belonging to a logical cpu. Every array
18  * in the kernel is sorted by the logical cpu number and not by the physical
19  * one which is causing all the confusion with __cpu_logical_map and
20  * cpu_number_map in other architectures.
21  */
22
23 #include <linux/module.h>
24 #include <linux/init.h>
25 #include <linux/mm.h>
26 #include <linux/err.h>
27 #include <linux/spinlock.h>
28 #include <linux/kernel_stat.h>
29 #include <linux/delay.h>
30 #include <linux/cache.h>
31 #include <linux/interrupt.h>
32 #include <linux/cpu.h>
33 #include <linux/timex.h>
34 #include <linux/bootmem.h>
35 #include <asm/ipl.h>
36 #include <asm/setup.h>
37 #include <asm/sigp.h>
38 #include <asm/pgalloc.h>
39 #include <asm/irq.h>
40 #include <asm/s390_ext.h>
41 #include <asm/cpcmd.h>
42 #include <asm/tlbflush.h>
43 #include <asm/timer.h>
44 #include <asm/lowcore.h>
45 #include <asm/sclp.h>
46 #include <asm/cpu.h>
47 #include "entry.h"
48
49 /*
50  * An array with a pointer the lowcore of every CPU.
51  */
52 struct _lowcore *lowcore_ptr[NR_CPUS];
53 EXPORT_SYMBOL(lowcore_ptr);
54
55 cpumask_t cpu_online_map = CPU_MASK_NONE;
56 EXPORT_SYMBOL(cpu_online_map);
57
58 cpumask_t cpu_possible_map = CPU_MASK_ALL;
59 EXPORT_SYMBOL(cpu_possible_map);
60
61 static struct task_struct *current_set[NR_CPUS];
62
63 static u8 smp_cpu_type;
64 static int smp_use_sigp_detection;
65
66 enum s390_cpu_state {
67         CPU_STATE_STANDBY,
68         CPU_STATE_CONFIGURED,
69 };
70
71 DEFINE_MUTEX(smp_cpu_state_mutex);
72 int smp_cpu_polarization[NR_CPUS];
73 static int smp_cpu_state[NR_CPUS];
74 static int cpu_management;
75
76 static DEFINE_PER_CPU(struct cpu, cpu_devices);
77
78 static void smp_ext_bitcall(int, ec_bit_sig);
79
80 /*
81  * Structure and data for __smp_call_function_map(). This is designed to
82  * minimise static memory requirements. It also looks cleaner.
83  */
84 static DEFINE_SPINLOCK(call_lock);
85
86 struct call_data_struct {
87         void (*func) (void *info);
88         void *info;
89         cpumask_t started;
90         cpumask_t finished;
91         int wait;
92 };
93
94 static struct call_data_struct *call_data;
95
96 /*
97  * 'Call function' interrupt callback
98  */
99 static void do_call_function(void)
100 {
101         void (*func) (void *info) = call_data->func;
102         void *info = call_data->info;
103         int wait = call_data->wait;
104
105         cpu_set(smp_processor_id(), call_data->started);
106         (*func)(info);
107         if (wait)
108                 cpu_set(smp_processor_id(), call_data->finished);;
109 }
110
111 static void __smp_call_function_map(void (*func) (void *info), void *info,
112                                     int wait, cpumask_t map)
113 {
114         struct call_data_struct data;
115         int cpu, local = 0;
116
117         /*
118          * Can deadlock when interrupts are disabled or if in wrong context.
119          */
120         WARN_ON(irqs_disabled() || in_irq());
121
122         /*
123          * Check for local function call. We have to have the same call order
124          * as in on_each_cpu() because of machine_restart_smp().
125          */
126         if (cpu_isset(smp_processor_id(), map)) {
127                 local = 1;
128                 cpu_clear(smp_processor_id(), map);
129         }
130
131         cpus_and(map, map, cpu_online_map);
132         if (cpus_empty(map))
133                 goto out;
134
135         data.func = func;
136         data.info = info;
137         data.started = CPU_MASK_NONE;
138         data.wait = wait;
139         if (wait)
140                 data.finished = CPU_MASK_NONE;
141
142         call_data = &data;
143
144         for_each_cpu_mask(cpu, map)
145                 smp_ext_bitcall(cpu, ec_call_function);
146
147         /* Wait for response */
148         while (!cpus_equal(map, data.started))
149                 cpu_relax();
150         if (wait)
151                 while (!cpus_equal(map, data.finished))
152                         cpu_relax();
153 out:
154         if (local) {
155                 local_irq_disable();
156                 func(info);
157                 local_irq_enable();
158         }
159 }
160
161 /*
162  * smp_call_function:
163  * @func: the function to run; this must be fast and non-blocking
164  * @info: an arbitrary pointer to pass to the function
165  * @wait: if true, wait (atomically) until function has completed on other CPUs
166  *
167  * Run a function on all other CPUs.
168  *
169  * You must not call this function with disabled interrupts, from a
170  * hardware interrupt handler or from a bottom half.
171  */
172 int smp_call_function(void (*func) (void *info), void *info, int wait)
173 {
174         cpumask_t map;
175
176         spin_lock(&call_lock);
177         map = cpu_online_map;
178         cpu_clear(smp_processor_id(), map);
179         __smp_call_function_map(func, info, wait, map);
180         spin_unlock(&call_lock);
181         return 0;
182 }
183 EXPORT_SYMBOL(smp_call_function);
184
185 /*
186  * smp_call_function_single:
187  * @cpu: the CPU where func should run
188  * @func: the function to run; this must be fast and non-blocking
189  * @info: an arbitrary pointer to pass to the function
190  * @wait: if true, wait (atomically) until function has completed on other CPUs
191  *
192  * Run a function on one processor.
193  *
194  * You must not call this function with disabled interrupts, from a
195  * hardware interrupt handler or from a bottom half.
196  */
197 int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
198                              int wait)
199 {
200         spin_lock(&call_lock);
201         __smp_call_function_map(func, info, wait, cpumask_of_cpu(cpu));
202         spin_unlock(&call_lock);
203         return 0;
204 }
205 EXPORT_SYMBOL(smp_call_function_single);
206
207 /**
208  * smp_call_function_mask(): Run a function on a set of other CPUs.
209  * @mask: The set of cpus to run on.  Must not include the current cpu.
210  * @func: The function to run. This must be fast and non-blocking.
211  * @info: An arbitrary pointer to pass to the function.
212  * @wait: If true, wait (atomically) until function has completed on other CPUs.
213  *
214  * Returns 0 on success, else a negative status code.
215  *
216  * If @wait is true, then returns once @func has returned; otherwise
217  * it returns just before the target cpu calls @func.
218  *
219  * You must not call this function with disabled interrupts or from a
220  * hardware interrupt handler or from a bottom half handler.
221  */
222 int smp_call_function_mask(cpumask_t mask, void (*func)(void *), void *info,
223                            int wait)
224 {
225         spin_lock(&call_lock);
226         cpu_clear(smp_processor_id(), mask);
227         __smp_call_function_map(func, info, wait, mask);
228         spin_unlock(&call_lock);
229         return 0;
230 }
231 EXPORT_SYMBOL(smp_call_function_mask);
232
233 void smp_send_stop(void)
234 {
235         int cpu, rc;
236
237         /* Disable all interrupts/machine checks */
238         __load_psw_mask(psw_kernel_bits & ~PSW_MASK_MCHECK);
239
240         /* write magic number to zero page (absolute 0) */
241         lowcore_ptr[smp_processor_id()]->panic_magic = __PANIC_MAGIC;
242
243         /* stop all processors */
244         for_each_online_cpu(cpu) {
245                 if (cpu == smp_processor_id())
246                         continue;
247                 do {
248                         rc = signal_processor(cpu, sigp_stop);
249                 } while (rc == sigp_busy);
250
251                 while (!smp_cpu_not_running(cpu))
252                         cpu_relax();
253         }
254 }
255
256 /*
257  * This is the main routine where commands issued by other
258  * cpus are handled.
259  */
260
261 static void do_ext_call_interrupt(__u16 code)
262 {
263         unsigned long bits;
264
265         /*
266          * handle bit signal external calls
267          *
268          * For the ec_schedule signal we have to do nothing. All the work
269          * is done automatically when we return from the interrupt.
270          */
271         bits = xchg(&S390_lowcore.ext_call_fast, 0);
272
273         if (test_bit(ec_call_function, &bits))
274                 do_call_function();
275 }
276
277 /*
278  * Send an external call sigp to another cpu and return without waiting
279  * for its completion.
280  */
281 static void smp_ext_bitcall(int cpu, ec_bit_sig sig)
282 {
283         /*
284          * Set signaling bit in lowcore of target cpu and kick it
285          */
286         set_bit(sig, (unsigned long *) &lowcore_ptr[cpu]->ext_call_fast);
287         while (signal_processor(cpu, sigp_emergency_signal) == sigp_busy)
288                 udelay(10);
289 }
290
291 #ifndef CONFIG_64BIT
292 /*
293  * this function sends a 'purge tlb' signal to another CPU.
294  */
295 static void smp_ptlb_callback(void *info)
296 {
297         __tlb_flush_local();
298 }
299
300 void smp_ptlb_all(void)
301 {
302         on_each_cpu(smp_ptlb_callback, NULL, 1);
303 }
304 EXPORT_SYMBOL(smp_ptlb_all);
305 #endif /* ! CONFIG_64BIT */
306
307 /*
308  * this function sends a 'reschedule' IPI to another CPU.
309  * it goes straight through and wastes no time serializing
310  * anything. Worst case is that we lose a reschedule ...
311  */
312 void smp_send_reschedule(int cpu)
313 {
314         smp_ext_bitcall(cpu, ec_schedule);
315 }
316
317 /*
318  * parameter area for the set/clear control bit callbacks
319  */
320 struct ec_creg_mask_parms {
321         unsigned long orvals[16];
322         unsigned long andvals[16];
323 };
324
325 /*
326  * callback for setting/clearing control bits
327  */
328 static void smp_ctl_bit_callback(void *info)
329 {
330         struct ec_creg_mask_parms *pp = info;
331         unsigned long cregs[16];
332         int i;
333
334         __ctl_store(cregs, 0, 15);
335         for (i = 0; i <= 15; i++)
336                 cregs[i] = (cregs[i] & pp->andvals[i]) | pp->orvals[i];
337         __ctl_load(cregs, 0, 15);
338 }
339
340 /*
341  * Set a bit in a control register of all cpus
342  */
343 void smp_ctl_set_bit(int cr, int bit)
344 {
345         struct ec_creg_mask_parms parms;
346
347         memset(&parms.orvals, 0, sizeof(parms.orvals));
348         memset(&parms.andvals, 0xff, sizeof(parms.andvals));
349         parms.orvals[cr] = 1 << bit;
350         on_each_cpu(smp_ctl_bit_callback, &parms, 1);
351 }
352 EXPORT_SYMBOL(smp_ctl_set_bit);
353
354 /*
355  * Clear a bit in a control register of all cpus
356  */
357 void smp_ctl_clear_bit(int cr, int bit)
358 {
359         struct ec_creg_mask_parms parms;
360
361         memset(&parms.orvals, 0, sizeof(parms.orvals));
362         memset(&parms.andvals, 0xff, sizeof(parms.andvals));
363         parms.andvals[cr] = ~(1L << bit);
364         on_each_cpu(smp_ctl_bit_callback, &parms, 1);
365 }
366 EXPORT_SYMBOL(smp_ctl_clear_bit);
367
368 /*
369  * In early ipl state a temp. logically cpu number is needed, so the sigp
370  * functions can be used to sense other cpus. Since NR_CPUS is >= 2 on
371  * CONFIG_SMP and the ipl cpu is logical cpu 0, it must be 1.
372  */
373 #define CPU_INIT_NO     1
374
375 #if defined(CONFIG_ZFCPDUMP) || defined(CONFIG_ZFCPDUMP_MODULE)
376
377 /*
378  * zfcpdump_prefix_array holds prefix registers for the following scenario:
379  * 64 bit zfcpdump kernel and 31 bit kernel which is to be dumped. We have to
380  * save its prefix registers, since they get lost, when switching from 31 bit
381  * to 64 bit.
382  */
383 unsigned int zfcpdump_prefix_array[NR_CPUS + 1] \
384         __attribute__((__section__(".data")));
385
386 static void __init smp_get_save_area(unsigned int cpu, unsigned int phy_cpu)
387 {
388         if (ipl_info.type != IPL_TYPE_FCP_DUMP)
389                 return;
390         if (cpu >= NR_CPUS) {
391                 printk(KERN_WARNING "Registers for cpu %i not saved since dump "
392                        "kernel was compiled with NR_CPUS=%i\n", cpu, NR_CPUS);
393                 return;
394         }
395         zfcpdump_save_areas[cpu] = kmalloc(sizeof(union save_area), GFP_KERNEL);
396         __cpu_logical_map[CPU_INIT_NO] = (__u16) phy_cpu;
397         while (signal_processor(CPU_INIT_NO, sigp_stop_and_store_status) ==
398                sigp_busy)
399                 cpu_relax();
400         memcpy(zfcpdump_save_areas[cpu],
401                (void *)(unsigned long) store_prefix() + SAVE_AREA_BASE,
402                SAVE_AREA_SIZE);
403 #ifdef CONFIG_64BIT
404         /* copy original prefix register */
405         zfcpdump_save_areas[cpu]->s390x.pref_reg = zfcpdump_prefix_array[cpu];
406 #endif
407 }
408
409 union save_area *zfcpdump_save_areas[NR_CPUS + 1];
410 EXPORT_SYMBOL_GPL(zfcpdump_save_areas);
411
412 #else
413
414 static inline void smp_get_save_area(unsigned int cpu, unsigned int phy_cpu) { }
415
416 #endif /* CONFIG_ZFCPDUMP || CONFIG_ZFCPDUMP_MODULE */
417
418 static int cpu_stopped(int cpu)
419 {
420         __u32 status;
421
422         /* Check for stopped state */
423         if (signal_processor_ps(&status, 0, cpu, sigp_sense) ==
424             sigp_status_stored) {
425                 if (status & 0x40)
426                         return 1;
427         }
428         return 0;
429 }
430
431 static int cpu_known(int cpu_id)
432 {
433         int cpu;
434
435         for_each_present_cpu(cpu) {
436                 if (__cpu_logical_map[cpu] == cpu_id)
437                         return 1;
438         }
439         return 0;
440 }
441
442 static int smp_rescan_cpus_sigp(cpumask_t avail)
443 {
444         int cpu_id, logical_cpu;
445
446         logical_cpu = first_cpu(avail);
447         if (logical_cpu == NR_CPUS)
448                 return 0;
449         for (cpu_id = 0; cpu_id <= 65535; cpu_id++) {
450                 if (cpu_known(cpu_id))
451                         continue;
452                 __cpu_logical_map[logical_cpu] = cpu_id;
453                 smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN;
454                 if (!cpu_stopped(logical_cpu))
455                         continue;
456                 cpu_set(logical_cpu, cpu_present_map);
457                 smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
458                 logical_cpu = next_cpu(logical_cpu, avail);
459                 if (logical_cpu == NR_CPUS)
460                         break;
461         }
462         return 0;
463 }
464
465 static int smp_rescan_cpus_sclp(cpumask_t avail)
466 {
467         struct sclp_cpu_info *info;
468         int cpu_id, logical_cpu, cpu;
469         int rc;
470
471         logical_cpu = first_cpu(avail);
472         if (logical_cpu == NR_CPUS)
473                 return 0;
474         info = kmalloc(sizeof(*info), GFP_KERNEL);
475         if (!info)
476                 return -ENOMEM;
477         rc = sclp_get_cpu_info(info);
478         if (rc)
479                 goto out;
480         for (cpu = 0; cpu < info->combined; cpu++) {
481                 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
482                         continue;
483                 cpu_id = info->cpu[cpu].address;
484                 if (cpu_known(cpu_id))
485                         continue;
486                 __cpu_logical_map[logical_cpu] = cpu_id;
487                 smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN;
488                 cpu_set(logical_cpu, cpu_present_map);
489                 if (cpu >= info->configured)
490                         smp_cpu_state[logical_cpu] = CPU_STATE_STANDBY;
491                 else
492                         smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
493                 logical_cpu = next_cpu(logical_cpu, avail);
494                 if (logical_cpu == NR_CPUS)
495                         break;
496         }
497 out:
498         kfree(info);
499         return rc;
500 }
501
502 static int __smp_rescan_cpus(void)
503 {
504         cpumask_t avail;
505
506         cpus_xor(avail, cpu_possible_map, cpu_present_map);
507         if (smp_use_sigp_detection)
508                 return smp_rescan_cpus_sigp(avail);
509         else
510                 return smp_rescan_cpus_sclp(avail);
511 }
512
513 static void __init smp_detect_cpus(void)
514 {
515         unsigned int cpu, c_cpus, s_cpus;
516         struct sclp_cpu_info *info;
517         u16 boot_cpu_addr, cpu_addr;
518
519         c_cpus = 1;
520         s_cpus = 0;
521         boot_cpu_addr = S390_lowcore.cpu_data.cpu_addr;
522         info = kmalloc(sizeof(*info), GFP_KERNEL);
523         if (!info)
524                 panic("smp_detect_cpus failed to allocate memory\n");
525         /* Use sigp detection algorithm if sclp doesn't work. */
526         if (sclp_get_cpu_info(info)) {
527                 smp_use_sigp_detection = 1;
528                 for (cpu = 0; cpu <= 65535; cpu++) {
529                         if (cpu == boot_cpu_addr)
530                                 continue;
531                         __cpu_logical_map[CPU_INIT_NO] = cpu;
532                         if (!cpu_stopped(CPU_INIT_NO))
533                                 continue;
534                         smp_get_save_area(c_cpus, cpu);
535                         c_cpus++;
536                 }
537                 goto out;
538         }
539
540         if (info->has_cpu_type) {
541                 for (cpu = 0; cpu < info->combined; cpu++) {
542                         if (info->cpu[cpu].address == boot_cpu_addr) {
543                                 smp_cpu_type = info->cpu[cpu].type;
544                                 break;
545                         }
546                 }
547         }
548
549         for (cpu = 0; cpu < info->combined; cpu++) {
550                 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
551                         continue;
552                 cpu_addr = info->cpu[cpu].address;
553                 if (cpu_addr == boot_cpu_addr)
554                         continue;
555                 __cpu_logical_map[CPU_INIT_NO] = cpu_addr;
556                 if (!cpu_stopped(CPU_INIT_NO)) {
557                         s_cpus++;
558                         continue;
559                 }
560                 smp_get_save_area(c_cpus, cpu_addr);
561                 c_cpus++;
562         }
563 out:
564         kfree(info);
565         printk(KERN_INFO "CPUs: %d configured, %d standby\n", c_cpus, s_cpus);
566         get_online_cpus();
567         __smp_rescan_cpus();
568         put_online_cpus();
569 }
570
571 /*
572  *      Activate a secondary processor.
573  */
574 int __cpuinit start_secondary(void *cpuvoid)
575 {
576         /* Setup the cpu */
577         cpu_init();
578         preempt_disable();
579         /* Enable TOD clock interrupts on the secondary cpu. */
580         init_cpu_timer();
581 #ifdef CONFIG_VIRT_TIMER
582         /* Enable cpu timer interrupts on the secondary cpu. */
583         init_cpu_vtimer();
584 #endif
585         /* Enable pfault pseudo page faults on this cpu. */
586         pfault_init();
587
588         /* call cpu notifiers */
589         notify_cpu_starting(smp_processor_id());
590         /* Mark this cpu as online */
591         spin_lock(&call_lock);
592         cpu_set(smp_processor_id(), cpu_online_map);
593         spin_unlock(&call_lock);
594         /* Switch on interrupts */
595         local_irq_enable();
596         /* Print info about this processor */
597         print_cpu_info(&S390_lowcore.cpu_data);
598         /* cpu_idle will call schedule for us */
599         cpu_idle();
600         return 0;
601 }
602
603 static void __init smp_create_idle(unsigned int cpu)
604 {
605         struct task_struct *p;
606
607         /*
608          *  don't care about the psw and regs settings since we'll never
609          *  reschedule the forked task.
610          */
611         p = fork_idle(cpu);
612         if (IS_ERR(p))
613                 panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p));
614         current_set[cpu] = p;
615 }
616
617 static int __cpuinit smp_alloc_lowcore(int cpu)
618 {
619         unsigned long async_stack, panic_stack;
620         struct _lowcore *lowcore;
621         int lc_order;
622
623         lc_order = sizeof(long) == 8 ? 1 : 0;
624         lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, lc_order);
625         if (!lowcore)
626                 return -ENOMEM;
627         async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
628         panic_stack = __get_free_page(GFP_KERNEL);
629         if (!panic_stack || !async_stack)
630                 goto out;
631         memcpy(lowcore, &S390_lowcore, 512);
632         memset((char *)lowcore + 512, 0, sizeof(*lowcore) - 512);
633         lowcore->async_stack = async_stack + ASYNC_SIZE;
634         lowcore->panic_stack = panic_stack + PAGE_SIZE;
635
636 #ifndef CONFIG_64BIT
637         if (MACHINE_HAS_IEEE) {
638                 unsigned long save_area;
639
640                 save_area = get_zeroed_page(GFP_KERNEL);
641                 if (!save_area)
642                         goto out_save_area;
643                 lowcore->extended_save_area_addr = (u32) save_area;
644         }
645 #endif
646         lowcore_ptr[cpu] = lowcore;
647         return 0;
648
649 #ifndef CONFIG_64BIT
650 out_save_area:
651         free_page(panic_stack);
652 #endif
653 out:
654         free_pages(async_stack, ASYNC_ORDER);
655         free_pages((unsigned long) lowcore, lc_order);
656         return -ENOMEM;
657 }
658
659 #ifdef CONFIG_HOTPLUG_CPU
660 static void smp_free_lowcore(int cpu)
661 {
662         struct _lowcore *lowcore;
663         int lc_order;
664
665         lc_order = sizeof(long) == 8 ? 1 : 0;
666         lowcore = lowcore_ptr[cpu];
667 #ifndef CONFIG_64BIT
668         if (MACHINE_HAS_IEEE)
669                 free_page((unsigned long) lowcore->extended_save_area_addr);
670 #endif
671         free_page(lowcore->panic_stack - PAGE_SIZE);
672         free_pages(lowcore->async_stack - ASYNC_SIZE, ASYNC_ORDER);
673         free_pages((unsigned long) lowcore, lc_order);
674         lowcore_ptr[cpu] = NULL;
675 }
676 #endif /* CONFIG_HOTPLUG_CPU */
677
678 /* Upping and downing of CPUs */
679 int __cpuinit __cpu_up(unsigned int cpu)
680 {
681         struct task_struct *idle;
682         struct _lowcore *cpu_lowcore;
683         struct stack_frame *sf;
684         sigp_ccode ccode;
685
686         if (smp_cpu_state[cpu] != CPU_STATE_CONFIGURED)
687                 return -EIO;
688         if (smp_alloc_lowcore(cpu))
689                 return -ENOMEM;
690
691         ccode = signal_processor_p((__u32)(unsigned long)(lowcore_ptr[cpu]),
692                                    cpu, sigp_set_prefix);
693         if (ccode) {
694                 printk("sigp_set_prefix failed for cpu %d "
695                        "with condition code %d\n",
696                        (int) cpu, (int) ccode);
697                 return -EIO;
698         }
699
700         idle = current_set[cpu];
701         cpu_lowcore = lowcore_ptr[cpu];
702         cpu_lowcore->kernel_stack = (unsigned long)
703                 task_stack_page(idle) + THREAD_SIZE;
704         cpu_lowcore->thread_info = (unsigned long) task_thread_info(idle);
705         sf = (struct stack_frame *) (cpu_lowcore->kernel_stack
706                                      - sizeof(struct pt_regs)
707                                      - sizeof(struct stack_frame));
708         memset(sf, 0, sizeof(struct stack_frame));
709         sf->gprs[9] = (unsigned long) sf;
710         cpu_lowcore->save_area[15] = (unsigned long) sf;
711         __ctl_store(cpu_lowcore->cregs_save_area, 0, 15);
712         asm volatile(
713                 "       stam    0,15,0(%0)"
714                 : : "a" (&cpu_lowcore->access_regs_save_area) : "memory");
715         cpu_lowcore->percpu_offset = __per_cpu_offset[cpu];
716         cpu_lowcore->current_task = (unsigned long) idle;
717         cpu_lowcore->cpu_data.cpu_nr = cpu;
718         cpu_lowcore->kernel_asce = S390_lowcore.kernel_asce;
719         cpu_lowcore->ipl_device = S390_lowcore.ipl_device;
720         eieio();
721
722         while (signal_processor(cpu, sigp_restart) == sigp_busy)
723                 udelay(10);
724
725         while (!cpu_online(cpu))
726                 cpu_relax();
727         return 0;
728 }
729
730 static int __init setup_possible_cpus(char *s)
731 {
732         int pcpus, cpu;
733
734         pcpus = simple_strtoul(s, NULL, 0);
735         cpu_possible_map = cpumask_of_cpu(0);
736         for (cpu = 1; cpu < pcpus && cpu < NR_CPUS; cpu++)
737                 cpu_set(cpu, cpu_possible_map);
738         return 0;
739 }
740 early_param("possible_cpus", setup_possible_cpus);
741
742 #ifdef CONFIG_HOTPLUG_CPU
743
744 int __cpu_disable(void)
745 {
746         struct ec_creg_mask_parms cr_parms;
747         int cpu = smp_processor_id();
748
749         cpu_clear(cpu, cpu_online_map);
750
751         /* Disable pfault pseudo page faults on this cpu. */
752         pfault_fini();
753
754         memset(&cr_parms.orvals, 0, sizeof(cr_parms.orvals));
755         memset(&cr_parms.andvals, 0xff, sizeof(cr_parms.andvals));
756
757         /* disable all external interrupts */
758         cr_parms.orvals[0] = 0;
759         cr_parms.andvals[0] = ~(1 << 15 | 1 << 14 | 1 << 13 | 1 << 12 |
760                                 1 << 11 | 1 << 10 | 1 <<  6 | 1 <<  4);
761         /* disable all I/O interrupts */
762         cr_parms.orvals[6] = 0;
763         cr_parms.andvals[6] = ~(1 << 31 | 1 << 30 | 1 << 29 | 1 << 28 |
764                                 1 << 27 | 1 << 26 | 1 << 25 | 1 << 24);
765         /* disable most machine checks */
766         cr_parms.orvals[14] = 0;
767         cr_parms.andvals[14] = ~(1 << 28 | 1 << 27 | 1 << 26 |
768                                  1 << 25 | 1 << 24);
769
770         smp_ctl_bit_callback(&cr_parms);
771
772         return 0;
773 }
774
775 void __cpu_die(unsigned int cpu)
776 {
777         /* Wait until target cpu is down */
778         while (!smp_cpu_not_running(cpu))
779                 cpu_relax();
780         smp_free_lowcore(cpu);
781         printk(KERN_INFO "Processor %d spun down\n", cpu);
782 }
783
784 void cpu_die(void)
785 {
786         idle_task_exit();
787         signal_processor(smp_processor_id(), sigp_stop);
788         BUG();
789         for (;;);
790 }
791
792 #endif /* CONFIG_HOTPLUG_CPU */
793
794 void __init smp_prepare_cpus(unsigned int max_cpus)
795 {
796 #ifndef CONFIG_64BIT
797         unsigned long save_area = 0;
798 #endif
799         unsigned long async_stack, panic_stack;
800         struct _lowcore *lowcore;
801         unsigned int cpu;
802         int lc_order;
803
804         smp_detect_cpus();
805
806         /* request the 0x1201 emergency signal external interrupt */
807         if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0)
808                 panic("Couldn't request external interrupt 0x1201");
809         print_cpu_info(&S390_lowcore.cpu_data);
810
811         /* Reallocate current lowcore, but keep its contents. */
812         lc_order = sizeof(long) == 8 ? 1 : 0;
813         lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, lc_order);
814         panic_stack = __get_free_page(GFP_KERNEL);
815         async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
816 #ifndef CONFIG_64BIT
817         if (MACHINE_HAS_IEEE)
818                 save_area = get_zeroed_page(GFP_KERNEL);
819 #endif
820         local_irq_disable();
821         local_mcck_disable();
822         lowcore_ptr[smp_processor_id()] = lowcore;
823         *lowcore = S390_lowcore;
824         lowcore->panic_stack = panic_stack + PAGE_SIZE;
825         lowcore->async_stack = async_stack + ASYNC_SIZE;
826 #ifndef CONFIG_64BIT
827         if (MACHINE_HAS_IEEE)
828                 lowcore->extended_save_area_addr = (u32) save_area;
829 #endif
830         set_prefix((u32)(unsigned long) lowcore);
831         local_mcck_enable();
832         local_irq_enable();
833         for_each_possible_cpu(cpu)
834                 if (cpu != smp_processor_id())
835                         smp_create_idle(cpu);
836 }
837
838 void __init smp_prepare_boot_cpu(void)
839 {
840         BUG_ON(smp_processor_id() != 0);
841
842         current_thread_info()->cpu = 0;
843         cpu_set(0, cpu_present_map);
844         cpu_set(0, cpu_online_map);
845         S390_lowcore.percpu_offset = __per_cpu_offset[0];
846         current_set[0] = current;
847         smp_cpu_state[0] = CPU_STATE_CONFIGURED;
848         smp_cpu_polarization[0] = POLARIZATION_UNKNWN;
849 }
850
851 void __init smp_cpus_done(unsigned int max_cpus)
852 {
853 }
854
855 /*
856  * the frequency of the profiling timer can be changed
857  * by writing a multiplier value into /proc/profile.
858  *
859  * usually you want to run this on all CPUs ;)
860  */
861 int setup_profiling_timer(unsigned int multiplier)
862 {
863         return 0;
864 }
865
866 #ifdef CONFIG_HOTPLUG_CPU
867 static ssize_t cpu_configure_show(struct sys_device *dev,
868                                 struct sysdev_attribute *attr, char *buf)
869 {
870         ssize_t count;
871
872         mutex_lock(&smp_cpu_state_mutex);
873         count = sprintf(buf, "%d\n", smp_cpu_state[dev->id]);
874         mutex_unlock(&smp_cpu_state_mutex);
875         return count;
876 }
877
878 static ssize_t cpu_configure_store(struct sys_device *dev,
879                                   struct sysdev_attribute *attr,
880                                   const char *buf, size_t count)
881 {
882         int cpu = dev->id;
883         int val, rc;
884         char delim;
885
886         if (sscanf(buf, "%d %c", &val, &delim) != 1)
887                 return -EINVAL;
888         if (val != 0 && val != 1)
889                 return -EINVAL;
890
891         get_online_cpus();
892         mutex_lock(&smp_cpu_state_mutex);
893         rc = -EBUSY;
894         if (cpu_online(cpu))
895                 goto out;
896         rc = 0;
897         switch (val) {
898         case 0:
899                 if (smp_cpu_state[cpu] == CPU_STATE_CONFIGURED) {
900                         rc = sclp_cpu_deconfigure(__cpu_logical_map[cpu]);
901                         if (!rc) {
902                                 smp_cpu_state[cpu] = CPU_STATE_STANDBY;
903                                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
904                         }
905                 }
906                 break;
907         case 1:
908                 if (smp_cpu_state[cpu] == CPU_STATE_STANDBY) {
909                         rc = sclp_cpu_configure(__cpu_logical_map[cpu]);
910                         if (!rc) {
911                                 smp_cpu_state[cpu] = CPU_STATE_CONFIGURED;
912                                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
913                         }
914                 }
915                 break;
916         default:
917                 break;
918         }
919 out:
920         mutex_unlock(&smp_cpu_state_mutex);
921         put_online_cpus();
922         return rc ? rc : count;
923 }
924 static SYSDEV_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
925 #endif /* CONFIG_HOTPLUG_CPU */
926
927 static ssize_t cpu_polarization_show(struct sys_device *dev,
928                                      struct sysdev_attribute *attr, char *buf)
929 {
930         int cpu = dev->id;
931         ssize_t count;
932
933         mutex_lock(&smp_cpu_state_mutex);
934         switch (smp_cpu_polarization[cpu]) {
935         case POLARIZATION_HRZ:
936                 count = sprintf(buf, "horizontal\n");
937                 break;
938         case POLARIZATION_VL:
939                 count = sprintf(buf, "vertical:low\n");
940                 break;
941         case POLARIZATION_VM:
942                 count = sprintf(buf, "vertical:medium\n");
943                 break;
944         case POLARIZATION_VH:
945                 count = sprintf(buf, "vertical:high\n");
946                 break;
947         default:
948                 count = sprintf(buf, "unknown\n");
949                 break;
950         }
951         mutex_unlock(&smp_cpu_state_mutex);
952         return count;
953 }
954 static SYSDEV_ATTR(polarization, 0444, cpu_polarization_show, NULL);
955
956 static ssize_t show_cpu_address(struct sys_device *dev,
957                                 struct sysdev_attribute *attr, char *buf)
958 {
959         return sprintf(buf, "%d\n", __cpu_logical_map[dev->id]);
960 }
961 static SYSDEV_ATTR(address, 0444, show_cpu_address, NULL);
962
963
964 static struct attribute *cpu_common_attrs[] = {
965 #ifdef CONFIG_HOTPLUG_CPU
966         &attr_configure.attr,
967 #endif
968         &attr_address.attr,
969         &attr_polarization.attr,
970         NULL,
971 };
972
973 static struct attribute_group cpu_common_attr_group = {
974         .attrs = cpu_common_attrs,
975 };
976
977 static ssize_t show_capability(struct sys_device *dev,
978                                 struct sysdev_attribute *attr, char *buf)
979 {
980         unsigned int capability;
981         int rc;
982
983         rc = get_cpu_capability(&capability);
984         if (rc)
985                 return rc;
986         return sprintf(buf, "%u\n", capability);
987 }
988 static SYSDEV_ATTR(capability, 0444, show_capability, NULL);
989
990 static ssize_t show_idle_count(struct sys_device *dev,
991                                 struct sysdev_attribute *attr, char *buf)
992 {
993         struct s390_idle_data *idle;
994         unsigned long long idle_count;
995
996         idle = &per_cpu(s390_idle, dev->id);
997         spin_lock_irq(&idle->lock);
998         idle_count = idle->idle_count;
999         spin_unlock_irq(&idle->lock);
1000         return sprintf(buf, "%llu\n", idle_count);
1001 }
1002 static SYSDEV_ATTR(idle_count, 0444, show_idle_count, NULL);
1003
1004 static ssize_t show_idle_time(struct sys_device *dev,
1005                                 struct sysdev_attribute *attr, char *buf)
1006 {
1007         struct s390_idle_data *idle;
1008         unsigned long long new_time;
1009
1010         idle = &per_cpu(s390_idle, dev->id);
1011         spin_lock_irq(&idle->lock);
1012         if (idle->in_idle) {
1013                 new_time = get_clock();
1014                 idle->idle_time += new_time - idle->idle_enter;
1015                 idle->idle_enter = new_time;
1016         }
1017         new_time = idle->idle_time;
1018         spin_unlock_irq(&idle->lock);
1019         return sprintf(buf, "%llu\n", new_time >> 12);
1020 }
1021 static SYSDEV_ATTR(idle_time_us, 0444, show_idle_time, NULL);
1022
1023 static struct attribute *cpu_online_attrs[] = {
1024         &attr_capability.attr,
1025         &attr_idle_count.attr,
1026         &attr_idle_time_us.attr,
1027         NULL,
1028 };
1029
1030 static struct attribute_group cpu_online_attr_group = {
1031         .attrs = cpu_online_attrs,
1032 };
1033
1034 static int __cpuinit smp_cpu_notify(struct notifier_block *self,
1035                                     unsigned long action, void *hcpu)
1036 {
1037         unsigned int cpu = (unsigned int)(long)hcpu;
1038         struct cpu *c = &per_cpu(cpu_devices, cpu);
1039         struct sys_device *s = &c->sysdev;
1040         struct s390_idle_data *idle;
1041
1042         switch (action) {
1043         case CPU_ONLINE:
1044         case CPU_ONLINE_FROZEN:
1045                 idle = &per_cpu(s390_idle, cpu);
1046                 spin_lock_irq(&idle->lock);
1047                 idle->idle_enter = 0;
1048                 idle->idle_time = 0;
1049                 idle->idle_count = 0;
1050                 spin_unlock_irq(&idle->lock);
1051                 if (sysfs_create_group(&s->kobj, &cpu_online_attr_group))
1052                         return NOTIFY_BAD;
1053                 break;
1054         case CPU_DEAD:
1055         case CPU_DEAD_FROZEN:
1056                 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
1057                 break;
1058         }
1059         return NOTIFY_OK;
1060 }
1061
1062 static struct notifier_block __cpuinitdata smp_cpu_nb = {
1063         .notifier_call = smp_cpu_notify,
1064 };
1065
1066 static int __devinit smp_add_present_cpu(int cpu)
1067 {
1068         struct cpu *c = &per_cpu(cpu_devices, cpu);
1069         struct sys_device *s = &c->sysdev;
1070         int rc;
1071
1072         c->hotpluggable = 1;
1073         rc = register_cpu(c, cpu);
1074         if (rc)
1075                 goto out;
1076         rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
1077         if (rc)
1078                 goto out_cpu;
1079         if (!cpu_online(cpu))
1080                 goto out;
1081         rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
1082         if (!rc)
1083                 return 0;
1084         sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
1085 out_cpu:
1086 #ifdef CONFIG_HOTPLUG_CPU
1087         unregister_cpu(c);
1088 #endif
1089 out:
1090         return rc;
1091 }
1092
1093 #ifdef CONFIG_HOTPLUG_CPU
1094
1095 int __ref smp_rescan_cpus(void)
1096 {
1097         cpumask_t newcpus;
1098         int cpu;
1099         int rc;
1100
1101         get_online_cpus();
1102         mutex_lock(&smp_cpu_state_mutex);
1103         newcpus = cpu_present_map;
1104         rc = __smp_rescan_cpus();
1105         if (rc)
1106                 goto out;
1107         cpus_andnot(newcpus, cpu_present_map, newcpus);
1108         for_each_cpu_mask(cpu, newcpus) {
1109                 rc = smp_add_present_cpu(cpu);
1110                 if (rc)
1111                         cpu_clear(cpu, cpu_present_map);
1112         }
1113         rc = 0;
1114 out:
1115         mutex_unlock(&smp_cpu_state_mutex);
1116         put_online_cpus();
1117         if (!cpus_empty(newcpus))
1118                 topology_schedule_update();
1119         return rc;
1120 }
1121
1122 static ssize_t __ref rescan_store(struct sys_device *dev,
1123                                   struct sysdev_attribute *attr,
1124                                   const char *buf,
1125                                   size_t count)
1126 {
1127         int rc;
1128
1129         rc = smp_rescan_cpus();
1130         return rc ? rc : count;
1131 }
1132 static SYSDEV_ATTR(rescan, 0200, NULL, rescan_store);
1133 #endif /* CONFIG_HOTPLUG_CPU */
1134
1135 static ssize_t dispatching_show(struct sys_device *dev,
1136                                 struct sysdev_attribute *attr,
1137                                 char *buf)
1138 {
1139         ssize_t count;
1140
1141         mutex_lock(&smp_cpu_state_mutex);
1142         count = sprintf(buf, "%d\n", cpu_management);
1143         mutex_unlock(&smp_cpu_state_mutex);
1144         return count;
1145 }
1146
1147 static ssize_t dispatching_store(struct sys_device *dev,
1148                                  struct sysdev_attribute *attr,
1149                                  const char *buf, size_t count)
1150 {
1151         int val, rc;
1152         char delim;
1153
1154         if (sscanf(buf, "%d %c", &val, &delim) != 1)
1155                 return -EINVAL;
1156         if (val != 0 && val != 1)
1157                 return -EINVAL;
1158         rc = 0;
1159         get_online_cpus();
1160         mutex_lock(&smp_cpu_state_mutex);
1161         if (cpu_management == val)
1162                 goto out;
1163         rc = topology_set_cpu_management(val);
1164         if (!rc)
1165                 cpu_management = val;
1166 out:
1167         mutex_unlock(&smp_cpu_state_mutex);
1168         put_online_cpus();
1169         return rc ? rc : count;
1170 }
1171 static SYSDEV_ATTR(dispatching, 0644, dispatching_show, dispatching_store);
1172
1173 static int __init topology_init(void)
1174 {
1175         int cpu;
1176         int rc;
1177
1178         register_cpu_notifier(&smp_cpu_nb);
1179
1180 #ifdef CONFIG_HOTPLUG_CPU
1181         rc = sysfs_create_file(&cpu_sysdev_class.kset.kobj,
1182                                &attr_rescan.attr);
1183         if (rc)
1184                 return rc;
1185 #endif
1186         rc = sysfs_create_file(&cpu_sysdev_class.kset.kobj,
1187                                &attr_dispatching.attr);
1188         if (rc)
1189                 return rc;
1190         for_each_present_cpu(cpu) {
1191                 rc = smp_add_present_cpu(cpu);
1192                 if (rc)
1193                         return rc;
1194         }
1195         return 0;
1196 }
1197 subsys_initcall(topology_init);