[S390] Fix build errors (fallout from system.h disintegration)
[linux-2.6.git] / arch / s390 / kernel / smp.c
1 /*
2  *  SMP related functions
3  *
4  *    Copyright IBM Corp. 1999,2012
5  *    Author(s): Denis Joseph Barrow,
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  * The code outside of smp.c uses logical cpu numbers, only smp.c does
14  * the translation of logical to physical cpu ids. All new code that
15  * operates on physical cpu numbers needs to go into smp.c.
16  */
17
18 #define KMSG_COMPONENT "cpu"
19 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
20
21 #include <linux/workqueue.h>
22 #include <linux/module.h>
23 #include <linux/init.h>
24 #include <linux/mm.h>
25 #include <linux/err.h>
26 #include <linux/spinlock.h>
27 #include <linux/kernel_stat.h>
28 #include <linux/delay.h>
29 #include <linux/interrupt.h>
30 #include <linux/irqflags.h>
31 #include <linux/cpu.h>
32 #include <linux/slab.h>
33 #include <linux/crash_dump.h>
34 #include <asm/asm-offsets.h>
35 #include <asm/switch_to.h>
36 #include <asm/facility.h>
37 #include <asm/ipl.h>
38 #include <asm/setup.h>
39 #include <asm/irq.h>
40 #include <asm/tlbflush.h>
41 #include <asm/timer.h>
42 #include <asm/lowcore.h>
43 #include <asm/sclp.h>
44 #include <asm/vdso.h>
45 #include <asm/debug.h>
46 #include <asm/os_info.h>
47 #include "entry.h"
48
49 enum {
50         sigp_sense = 1,
51         sigp_external_call = 2,
52         sigp_emergency_signal = 3,
53         sigp_start = 4,
54         sigp_stop = 5,
55         sigp_restart = 6,
56         sigp_stop_and_store_status = 9,
57         sigp_initial_cpu_reset = 11,
58         sigp_cpu_reset = 12,
59         sigp_set_prefix = 13,
60         sigp_store_status_at_address = 14,
61         sigp_store_extended_status_at_address = 15,
62         sigp_set_architecture = 18,
63         sigp_conditional_emergency_signal = 19,
64         sigp_sense_running = 21,
65 };
66
67 enum {
68         sigp_order_code_accepted = 0,
69         sigp_status_stored = 1,
70         sigp_busy = 2,
71         sigp_not_operational = 3,
72 };
73
74 enum {
75         ec_schedule = 0,
76         ec_call_function,
77         ec_call_function_single,
78         ec_stop_cpu,
79 };
80
81 enum {
82         CPU_STATE_STANDBY,
83         CPU_STATE_CONFIGURED,
84 };
85
86 struct pcpu {
87         struct cpu cpu;
88         struct task_struct *idle;       /* idle process for the cpu */
89         struct _lowcore *lowcore;       /* lowcore page(s) for the cpu */
90         unsigned long async_stack;      /* async stack for the cpu */
91         unsigned long panic_stack;      /* panic stack for the cpu */
92         unsigned long ec_mask;          /* bit mask for ec_xxx functions */
93         int state;                      /* physical cpu state */
94         u32 status;                     /* last status received via sigp */
95         u16 address;                    /* physical cpu address */
96 };
97
98 static u8 boot_cpu_type;
99 static u16 boot_cpu_address;
100 static struct pcpu pcpu_devices[NR_CPUS];
101
102 DEFINE_MUTEX(smp_cpu_state_mutex);
103
104 /*
105  * Signal processor helper functions.
106  */
107 static inline int __pcpu_sigp(u16 addr, u8 order, u32 parm, u32 *status)
108 {
109         register unsigned int reg1 asm ("1") = parm;
110         int cc;
111
112         asm volatile(
113                 "       sigp    %1,%2,0(%3)\n"
114                 "       ipm     %0\n"
115                 "       srl     %0,28\n"
116                 : "=d" (cc), "+d" (reg1) : "d" (addr), "a" (order) : "cc");
117         if (status && cc == 1)
118                 *status = reg1;
119         return cc;
120 }
121
122 static inline int __pcpu_sigp_relax(u16 addr, u8 order, u32 parm, u32 *status)
123 {
124         int cc;
125
126         while (1) {
127                 cc = __pcpu_sigp(addr, order, parm, status);
128                 if (cc != sigp_busy)
129                         return cc;
130                 cpu_relax();
131         }
132 }
133
134 static int pcpu_sigp_retry(struct pcpu *pcpu, u8 order, u32 parm)
135 {
136         int cc, retry;
137
138         for (retry = 0; ; retry++) {
139                 cc = __pcpu_sigp(pcpu->address, order, parm, &pcpu->status);
140                 if (cc != sigp_busy)
141                         break;
142                 if (retry >= 3)
143                         udelay(10);
144         }
145         return cc;
146 }
147
148 static inline int pcpu_stopped(struct pcpu *pcpu)
149 {
150         if (__pcpu_sigp(pcpu->address, sigp_sense,
151                         0, &pcpu->status) != sigp_status_stored)
152                 return 0;
153         /* Check for stopped and check stop state */
154         return !!(pcpu->status & 0x50);
155 }
156
157 static inline int pcpu_running(struct pcpu *pcpu)
158 {
159         if (__pcpu_sigp(pcpu->address, sigp_sense_running,
160                         0, &pcpu->status) != sigp_status_stored)
161                 return 1;
162         /* Check for running status */
163         return !(pcpu->status & 0x400);
164 }
165
166 /*
167  * Find struct pcpu by cpu address.
168  */
169 static struct pcpu *pcpu_find_address(const struct cpumask *mask, int address)
170 {
171         int cpu;
172
173         for_each_cpu(cpu, mask)
174                 if (pcpu_devices[cpu].address == address)
175                         return pcpu_devices + cpu;
176         return NULL;
177 }
178
179 static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit)
180 {
181         int order;
182
183         set_bit(ec_bit, &pcpu->ec_mask);
184         order = pcpu_running(pcpu) ?
185                 sigp_external_call : sigp_emergency_signal;
186         pcpu_sigp_retry(pcpu, order, 0);
187 }
188
189 static int __cpuinit pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
190 {
191         struct _lowcore *lc;
192
193         if (pcpu != &pcpu_devices[0]) {
194                 pcpu->lowcore = (struct _lowcore *)
195                         __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
196                 pcpu->async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
197                 pcpu->panic_stack = __get_free_page(GFP_KERNEL);
198                 if (!pcpu->lowcore || !pcpu->panic_stack || !pcpu->async_stack)
199                         goto out;
200         }
201         lc = pcpu->lowcore;
202         memcpy(lc, &S390_lowcore, 512);
203         memset((char *) lc + 512, 0, sizeof(*lc) - 512);
204         lc->async_stack = pcpu->async_stack + ASYNC_SIZE;
205         lc->panic_stack = pcpu->panic_stack + PAGE_SIZE;
206         lc->cpu_nr = cpu;
207 #ifndef CONFIG_64BIT
208         if (MACHINE_HAS_IEEE) {
209                 lc->extended_save_area_addr = get_zeroed_page(GFP_KERNEL);
210                 if (!lc->extended_save_area_addr)
211                         goto out;
212         }
213 #else
214         if (vdso_alloc_per_cpu(lc))
215                 goto out;
216 #endif
217         lowcore_ptr[cpu] = lc;
218         pcpu_sigp_retry(pcpu, sigp_set_prefix, (u32)(unsigned long) lc);
219         return 0;
220 out:
221         if (pcpu != &pcpu_devices[0]) {
222                 free_page(pcpu->panic_stack);
223                 free_pages(pcpu->async_stack, ASYNC_ORDER);
224                 free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
225         }
226         return -ENOMEM;
227 }
228
229 static void pcpu_free_lowcore(struct pcpu *pcpu)
230 {
231         pcpu_sigp_retry(pcpu, sigp_set_prefix, 0);
232         lowcore_ptr[pcpu - pcpu_devices] = NULL;
233 #ifndef CONFIG_64BIT
234         if (MACHINE_HAS_IEEE) {
235                 struct _lowcore *lc = pcpu->lowcore;
236
237                 free_page((unsigned long) lc->extended_save_area_addr);
238                 lc->extended_save_area_addr = 0;
239         }
240 #else
241         vdso_free_per_cpu(pcpu->lowcore);
242 #endif
243         if (pcpu != &pcpu_devices[0]) {
244                 free_page(pcpu->panic_stack);
245                 free_pages(pcpu->async_stack, ASYNC_ORDER);
246                 free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
247         }
248 }
249
250 static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu)
251 {
252         struct _lowcore *lc = pcpu->lowcore;
253
254         atomic_inc(&init_mm.context.attach_count);
255         lc->cpu_nr = cpu;
256         lc->percpu_offset = __per_cpu_offset[cpu];
257         lc->kernel_asce = S390_lowcore.kernel_asce;
258         lc->machine_flags = S390_lowcore.machine_flags;
259         lc->ftrace_func = S390_lowcore.ftrace_func;
260         lc->user_timer = lc->system_timer = lc->steal_timer = 0;
261         __ctl_store(lc->cregs_save_area, 0, 15);
262         save_access_regs((unsigned int *) lc->access_regs_save_area);
263         memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,
264                MAX_FACILITY_BIT/8);
265 }
266
267 static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk)
268 {
269         struct _lowcore *lc = pcpu->lowcore;
270         struct thread_info *ti = task_thread_info(tsk);
271
272         lc->kernel_stack = (unsigned long) task_stack_page(tsk) + THREAD_SIZE;
273         lc->thread_info = (unsigned long) task_thread_info(tsk);
274         lc->current_task = (unsigned long) tsk;
275         lc->user_timer = ti->user_timer;
276         lc->system_timer = ti->system_timer;
277         lc->steal_timer = 0;
278 }
279
280 static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data)
281 {
282         struct _lowcore *lc = pcpu->lowcore;
283
284         lc->restart_stack = lc->kernel_stack;
285         lc->restart_fn = (unsigned long) func;
286         lc->restart_data = (unsigned long) data;
287         lc->restart_source = -1UL;
288         pcpu_sigp_retry(pcpu, sigp_restart, 0);
289 }
290
291 /*
292  * Call function via PSW restart on pcpu and stop the current cpu.
293  */
294 static void pcpu_delegate(struct pcpu *pcpu, void (*func)(void *),
295                           void *data, unsigned long stack)
296 {
297         struct _lowcore *lc = pcpu->lowcore;
298         unsigned short this_cpu;
299
300         __load_psw_mask(psw_kernel_bits);
301         this_cpu = stap();
302         if (pcpu->address == this_cpu)
303                 func(data);     /* should not return */
304         /* Stop target cpu (if func returns this stops the current cpu). */
305         pcpu_sigp_retry(pcpu, sigp_stop, 0);
306         /* Restart func on the target cpu and stop the current cpu. */
307         lc->restart_stack = stack;
308         lc->restart_fn = (unsigned long) func;
309         lc->restart_data = (unsigned long) data;
310         lc->restart_source = (unsigned long) this_cpu;
311         asm volatile(
312                 "0:     sigp    0,%0,6  # sigp restart to target cpu\n"
313                 "       brc     2,0b    # busy, try again\n"
314                 "1:     sigp    0,%1,5  # sigp stop to current cpu\n"
315                 "       brc     2,1b    # busy, try again\n"
316                 : : "d" (pcpu->address), "d" (this_cpu) : "0", "1", "cc");
317         for (;;) ;
318 }
319
320 /*
321  * Call function on an online CPU.
322  */
323 void smp_call_online_cpu(void (*func)(void *), void *data)
324 {
325         struct pcpu *pcpu;
326
327         /* Use the current cpu if it is online. */
328         pcpu = pcpu_find_address(cpu_online_mask, stap());
329         if (!pcpu)
330                 /* Use the first online cpu. */
331                 pcpu = pcpu_devices + cpumask_first(cpu_online_mask);
332         pcpu_delegate(pcpu, func, data, (unsigned long) restart_stack);
333 }
334
335 /*
336  * Call function on the ipl CPU.
337  */
338 void smp_call_ipl_cpu(void (*func)(void *), void *data)
339 {
340         pcpu_delegate(&pcpu_devices[0], func, data,
341                       pcpu_devices->panic_stack + PAGE_SIZE);
342 }
343
344 int smp_find_processor_id(u16 address)
345 {
346         int cpu;
347
348         for_each_present_cpu(cpu)
349                 if (pcpu_devices[cpu].address == address)
350                         return cpu;
351         return -1;
352 }
353
354 int smp_vcpu_scheduled(int cpu)
355 {
356         return pcpu_running(pcpu_devices + cpu);
357 }
358
359 void smp_yield(void)
360 {
361         if (MACHINE_HAS_DIAG44)
362                 asm volatile("diag 0,0,0x44");
363 }
364
365 void smp_yield_cpu(int cpu)
366 {
367         if (MACHINE_HAS_DIAG9C)
368                 asm volatile("diag %0,0,0x9c"
369                              : : "d" (pcpu_devices[cpu].address));
370         else if (MACHINE_HAS_DIAG44)
371                 asm volatile("diag 0,0,0x44");
372 }
373
374 /*
375  * Send cpus emergency shutdown signal. This gives the cpus the
376  * opportunity to complete outstanding interrupts.
377  */
378 void smp_emergency_stop(cpumask_t *cpumask)
379 {
380         u64 end;
381         int cpu;
382
383         end = get_clock() + (1000000UL << 12);
384         for_each_cpu(cpu, cpumask) {
385                 struct pcpu *pcpu = pcpu_devices + cpu;
386                 set_bit(ec_stop_cpu, &pcpu->ec_mask);
387                 while (__pcpu_sigp(pcpu->address, sigp_emergency_signal,
388                                    0, NULL) == sigp_busy &&
389                        get_clock() < end)
390                         cpu_relax();
391         }
392         while (get_clock() < end) {
393                 for_each_cpu(cpu, cpumask)
394                         if (pcpu_stopped(pcpu_devices + cpu))
395                                 cpumask_clear_cpu(cpu, cpumask);
396                 if (cpumask_empty(cpumask))
397                         break;
398                 cpu_relax();
399         }
400 }
401
402 /*
403  * Stop all cpus but the current one.
404  */
405 void smp_send_stop(void)
406 {
407         cpumask_t cpumask;
408         int cpu;
409
410         /* Disable all interrupts/machine checks */
411         __load_psw_mask(psw_kernel_bits | PSW_MASK_DAT);
412         trace_hardirqs_off();
413
414         debug_set_critical();
415         cpumask_copy(&cpumask, cpu_online_mask);
416         cpumask_clear_cpu(smp_processor_id(), &cpumask);
417
418         if (oops_in_progress)
419                 smp_emergency_stop(&cpumask);
420
421         /* stop all processors */
422         for_each_cpu(cpu, &cpumask) {
423                 struct pcpu *pcpu = pcpu_devices + cpu;
424                 pcpu_sigp_retry(pcpu, sigp_stop, 0);
425                 while (!pcpu_stopped(pcpu))
426                         cpu_relax();
427         }
428 }
429
430 /*
431  * Stop the current cpu.
432  */
433 void smp_stop_cpu(void)
434 {
435         pcpu_sigp_retry(pcpu_devices + smp_processor_id(), sigp_stop, 0);
436         for (;;) ;
437 }
438
439 /*
440  * This is the main routine where commands issued by other
441  * cpus are handled.
442  */
443 static void do_ext_call_interrupt(struct ext_code ext_code,
444                                   unsigned int param32, unsigned long param64)
445 {
446         unsigned long bits;
447         int cpu;
448
449         cpu = smp_processor_id();
450         if (ext_code.code == 0x1202)
451                 kstat_cpu(cpu).irqs[EXTINT_EXC]++;
452         else
453                 kstat_cpu(cpu).irqs[EXTINT_EMS]++;
454         /*
455          * handle bit signal external calls
456          */
457         bits = xchg(&pcpu_devices[cpu].ec_mask, 0);
458
459         if (test_bit(ec_stop_cpu, &bits))
460                 smp_stop_cpu();
461
462         if (test_bit(ec_schedule, &bits))
463                 scheduler_ipi();
464
465         if (test_bit(ec_call_function, &bits))
466                 generic_smp_call_function_interrupt();
467
468         if (test_bit(ec_call_function_single, &bits))
469                 generic_smp_call_function_single_interrupt();
470
471 }
472
473 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
474 {
475         int cpu;
476
477         for_each_cpu(cpu, mask)
478                 pcpu_ec_call(pcpu_devices + cpu, ec_call_function);
479 }
480
481 void arch_send_call_function_single_ipi(int cpu)
482 {
483         pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
484 }
485
486 #ifndef CONFIG_64BIT
487 /*
488  * this function sends a 'purge tlb' signal to another CPU.
489  */
490 static void smp_ptlb_callback(void *info)
491 {
492         __tlb_flush_local();
493 }
494
495 void smp_ptlb_all(void)
496 {
497         on_each_cpu(smp_ptlb_callback, NULL, 1);
498 }
499 EXPORT_SYMBOL(smp_ptlb_all);
500 #endif /* ! CONFIG_64BIT */
501
502 /*
503  * this function sends a 'reschedule' IPI to another CPU.
504  * it goes straight through and wastes no time serializing
505  * anything. Worst case is that we lose a reschedule ...
506  */
507 void smp_send_reschedule(int cpu)
508 {
509         pcpu_ec_call(pcpu_devices + cpu, ec_schedule);
510 }
511
512 /*
513  * parameter area for the set/clear control bit callbacks
514  */
515 struct ec_creg_mask_parms {
516         unsigned long orval;
517         unsigned long andval;
518         int cr;
519 };
520
521 /*
522  * callback for setting/clearing control bits
523  */
524 static void smp_ctl_bit_callback(void *info)
525 {
526         struct ec_creg_mask_parms *pp = info;
527         unsigned long cregs[16];
528
529         __ctl_store(cregs, 0, 15);
530         cregs[pp->cr] = (cregs[pp->cr] & pp->andval) | pp->orval;
531         __ctl_load(cregs, 0, 15);
532 }
533
534 /*
535  * Set a bit in a control register of all cpus
536  */
537 void smp_ctl_set_bit(int cr, int bit)
538 {
539         struct ec_creg_mask_parms parms = { 1UL << bit, -1UL, cr };
540
541         on_each_cpu(smp_ctl_bit_callback, &parms, 1);
542 }
543 EXPORT_SYMBOL(smp_ctl_set_bit);
544
545 /*
546  * Clear a bit in a control register of all cpus
547  */
548 void smp_ctl_clear_bit(int cr, int bit)
549 {
550         struct ec_creg_mask_parms parms = { 0, ~(1UL << bit), cr };
551
552         on_each_cpu(smp_ctl_bit_callback, &parms, 1);
553 }
554 EXPORT_SYMBOL(smp_ctl_clear_bit);
555
556 #if defined(CONFIG_ZFCPDUMP) || defined(CONFIG_CRASH_DUMP)
557
558 struct save_area *zfcpdump_save_areas[NR_CPUS + 1];
559 EXPORT_SYMBOL_GPL(zfcpdump_save_areas);
560
561 static void __init smp_get_save_area(int cpu, u16 address)
562 {
563         void *lc = pcpu_devices[0].lowcore;
564         struct save_area *save_area;
565
566         if (is_kdump_kernel())
567                 return;
568         if (!OLDMEM_BASE && (address == boot_cpu_address ||
569                              ipl_info.type != IPL_TYPE_FCP_DUMP))
570                 return;
571         if (cpu >= NR_CPUS) {
572                 pr_warning("CPU %i exceeds the maximum %i and is excluded "
573                            "from the dump\n", cpu, NR_CPUS - 1);
574                 return;
575         }
576         save_area = kmalloc(sizeof(struct save_area), GFP_KERNEL);
577         if (!save_area)
578                 panic("could not allocate memory for save area\n");
579         zfcpdump_save_areas[cpu] = save_area;
580 #ifdef CONFIG_CRASH_DUMP
581         if (address == boot_cpu_address) {
582                 /* Copy the registers of the boot cpu. */
583                 copy_oldmem_page(1, (void *) save_area, sizeof(*save_area),
584                                  SAVE_AREA_BASE - PAGE_SIZE, 0);
585                 return;
586         }
587 #endif
588         /* Get the registers of a non-boot cpu. */
589         __pcpu_sigp_relax(address, sigp_stop_and_store_status, 0, NULL);
590         memcpy_real(save_area, lc + SAVE_AREA_BASE, sizeof(*save_area));
591 }
592
593 int smp_store_status(int cpu)
594 {
595         struct pcpu *pcpu;
596
597         pcpu = pcpu_devices + cpu;
598         if (__pcpu_sigp_relax(pcpu->address, sigp_stop_and_store_status,
599                               0, NULL) != sigp_order_code_accepted)
600                 return -EIO;
601         return 0;
602 }
603
604 #else /* CONFIG_ZFCPDUMP || CONFIG_CRASH_DUMP */
605
606 static inline void smp_get_save_area(int cpu, u16 address) { }
607
608 #endif /* CONFIG_ZFCPDUMP || CONFIG_CRASH_DUMP */
609
610 static struct sclp_cpu_info *smp_get_cpu_info(void)
611 {
612         static int use_sigp_detection;
613         struct sclp_cpu_info *info;
614         int address;
615
616         info = kzalloc(sizeof(*info), GFP_KERNEL);
617         if (info && (use_sigp_detection || sclp_get_cpu_info(info))) {
618                 use_sigp_detection = 1;
619                 for (address = 0; address <= MAX_CPU_ADDRESS; address++) {
620                         if (__pcpu_sigp_relax(address, sigp_sense, 0, NULL) ==
621                             sigp_not_operational)
622                                 continue;
623                         info->cpu[info->configured].address = address;
624                         info->configured++;
625                 }
626                 info->combined = info->configured;
627         }
628         return info;
629 }
630
631 static int __devinit smp_add_present_cpu(int cpu);
632
633 static int __devinit __smp_rescan_cpus(struct sclp_cpu_info *info,
634                                        int sysfs_add)
635 {
636         struct pcpu *pcpu;
637         cpumask_t avail;
638         int cpu, nr, i;
639
640         nr = 0;
641         cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask);
642         cpu = cpumask_first(&avail);
643         for (i = 0; (i < info->combined) && (cpu < nr_cpu_ids); i++) {
644                 if (info->has_cpu_type && info->cpu[i].type != boot_cpu_type)
645                         continue;
646                 if (pcpu_find_address(cpu_present_mask, info->cpu[i].address))
647                         continue;
648                 pcpu = pcpu_devices + cpu;
649                 pcpu->address = info->cpu[i].address;
650                 pcpu->state = (cpu >= info->configured) ?
651                         CPU_STATE_STANDBY : CPU_STATE_CONFIGURED;
652                 cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
653                 set_cpu_present(cpu, true);
654                 if (sysfs_add && smp_add_present_cpu(cpu) != 0)
655                         set_cpu_present(cpu, false);
656                 else
657                         nr++;
658                 cpu = cpumask_next(cpu, &avail);
659         }
660         return nr;
661 }
662
663 static void __init smp_detect_cpus(void)
664 {
665         unsigned int cpu, c_cpus, s_cpus;
666         struct sclp_cpu_info *info;
667
668         info = smp_get_cpu_info();
669         if (!info)
670                 panic("smp_detect_cpus failed to allocate memory\n");
671         if (info->has_cpu_type) {
672                 for (cpu = 0; cpu < info->combined; cpu++) {
673                         if (info->cpu[cpu].address != boot_cpu_address)
674                                 continue;
675                         /* The boot cpu dictates the cpu type. */
676                         boot_cpu_type = info->cpu[cpu].type;
677                         break;
678                 }
679         }
680         c_cpus = s_cpus = 0;
681         for (cpu = 0; cpu < info->combined; cpu++) {
682                 if (info->has_cpu_type && info->cpu[cpu].type != boot_cpu_type)
683                         continue;
684                 if (cpu < info->configured) {
685                         smp_get_save_area(c_cpus, info->cpu[cpu].address);
686                         c_cpus++;
687                 } else
688                         s_cpus++;
689         }
690         pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
691         get_online_cpus();
692         __smp_rescan_cpus(info, 0);
693         put_online_cpus();
694         kfree(info);
695 }
696
697 /*
698  *      Activate a secondary processor.
699  */
700 static void __cpuinit smp_start_secondary(void *cpuvoid)
701 {
702         S390_lowcore.last_update_clock = get_clock();
703         S390_lowcore.restart_stack = (unsigned long) restart_stack;
704         S390_lowcore.restart_fn = (unsigned long) do_restart;
705         S390_lowcore.restart_data = 0;
706         S390_lowcore.restart_source = -1UL;
707         restore_access_regs(S390_lowcore.access_regs_save_area);
708         __ctl_load(S390_lowcore.cregs_save_area, 0, 15);
709         __load_psw_mask(psw_kernel_bits | PSW_MASK_DAT);
710         cpu_init();
711         preempt_disable();
712         init_cpu_timer();
713         init_cpu_vtimer();
714         pfault_init();
715         notify_cpu_starting(smp_processor_id());
716         ipi_call_lock();
717         set_cpu_online(smp_processor_id(), true);
718         ipi_call_unlock();
719         local_irq_enable();
720         /* cpu_idle will call schedule for us */
721         cpu_idle();
722 }
723
724 struct create_idle {
725         struct work_struct work;
726         struct task_struct *idle;
727         struct completion done;
728         int cpu;
729 };
730
731 static void __cpuinit smp_fork_idle(struct work_struct *work)
732 {
733         struct create_idle *c_idle;
734
735         c_idle = container_of(work, struct create_idle, work);
736         c_idle->idle = fork_idle(c_idle->cpu);
737         complete(&c_idle->done);
738 }
739
740 /* Upping and downing of CPUs */
741 int __cpuinit __cpu_up(unsigned int cpu)
742 {
743         struct create_idle c_idle;
744         struct pcpu *pcpu;
745         int rc;
746
747         pcpu = pcpu_devices + cpu;
748         if (pcpu->state != CPU_STATE_CONFIGURED)
749                 return -EIO;
750         if (pcpu_sigp_retry(pcpu, sigp_initial_cpu_reset, 0) !=
751             sigp_order_code_accepted)
752                 return -EIO;
753         if (!pcpu->idle) {
754                 c_idle.done = COMPLETION_INITIALIZER_ONSTACK(c_idle.done);
755                 INIT_WORK_ONSTACK(&c_idle.work, smp_fork_idle);
756                 c_idle.cpu = cpu;
757                 schedule_work(&c_idle.work);
758                 wait_for_completion(&c_idle.done);
759                 if (IS_ERR(c_idle.idle))
760                         return PTR_ERR(c_idle.idle);
761                 pcpu->idle = c_idle.idle;
762         }
763         init_idle(pcpu->idle, cpu);
764         rc = pcpu_alloc_lowcore(pcpu, cpu);
765         if (rc)
766                 return rc;
767         pcpu_prepare_secondary(pcpu, cpu);
768         pcpu_attach_task(pcpu, pcpu->idle);
769         pcpu_start_fn(pcpu, smp_start_secondary, NULL);
770         while (!cpu_online(cpu))
771                 cpu_relax();
772         return 0;
773 }
774
775 static int __init setup_possible_cpus(char *s)
776 {
777         int max, cpu;
778
779         if (kstrtoint(s, 0, &max) < 0)
780                 return 0;
781         init_cpu_possible(cpumask_of(0));
782         for (cpu = 1; cpu < max && cpu < nr_cpu_ids; cpu++)
783                 set_cpu_possible(cpu, true);
784         return 0;
785 }
786 early_param("possible_cpus", setup_possible_cpus);
787
788 #ifdef CONFIG_HOTPLUG_CPU
789
790 int __cpu_disable(void)
791 {
792         unsigned long cregs[16];
793
794         set_cpu_online(smp_processor_id(), false);
795         /* Disable pseudo page faults on this cpu. */
796         pfault_fini();
797         /* Disable interrupt sources via control register. */
798         __ctl_store(cregs, 0, 15);
799         cregs[0]  &= ~0x0000ee70UL;     /* disable all external interrupts */
800         cregs[6]  &= ~0xff000000UL;     /* disable all I/O interrupts */
801         cregs[14] &= ~0x1f000000UL;     /* disable most machine checks */
802         __ctl_load(cregs, 0, 15);
803         return 0;
804 }
805
806 void __cpu_die(unsigned int cpu)
807 {
808         struct pcpu *pcpu;
809
810         /* Wait until target cpu is down */
811         pcpu = pcpu_devices + cpu;
812         while (!pcpu_stopped(pcpu))
813                 cpu_relax();
814         pcpu_free_lowcore(pcpu);
815         atomic_dec(&init_mm.context.attach_count);
816 }
817
818 void __noreturn cpu_die(void)
819 {
820         idle_task_exit();
821         pcpu_sigp_retry(pcpu_devices + smp_processor_id(), sigp_stop, 0);
822         for (;;) ;
823 }
824
825 #endif /* CONFIG_HOTPLUG_CPU */
826
827 static void smp_call_os_info_init_fn(void)
828 {
829         int (*init_fn)(void);
830         unsigned long size;
831
832         init_fn = os_info_old_entry(OS_INFO_INIT_FN, &size);
833         if (!init_fn)
834                 return;
835         init_fn();
836 }
837
838 void __init smp_prepare_cpus(unsigned int max_cpus)
839 {
840         /* request the 0x1201 emergency signal external interrupt */
841         if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0)
842                 panic("Couldn't request external interrupt 0x1201");
843         /* request the 0x1202 external call external interrupt */
844         if (register_external_interrupt(0x1202, do_ext_call_interrupt) != 0)
845                 panic("Couldn't request external interrupt 0x1202");
846         smp_call_os_info_init_fn();
847         smp_detect_cpus();
848 }
849
850 void __init smp_prepare_boot_cpu(void)
851 {
852         struct pcpu *pcpu = pcpu_devices;
853
854         boot_cpu_address = stap();
855         pcpu->idle = current;
856         pcpu->state = CPU_STATE_CONFIGURED;
857         pcpu->address = boot_cpu_address;
858         pcpu->lowcore = (struct _lowcore *)(unsigned long) store_prefix();
859         pcpu->async_stack = S390_lowcore.async_stack - ASYNC_SIZE;
860         pcpu->panic_stack = S390_lowcore.panic_stack - PAGE_SIZE;
861         S390_lowcore.percpu_offset = __per_cpu_offset[0];
862         cpu_set_polarization(0, POLARIZATION_UNKNOWN);
863         set_cpu_present(0, true);
864         set_cpu_online(0, true);
865 }
866
867 void __init smp_cpus_done(unsigned int max_cpus)
868 {
869 }
870
871 void __init smp_setup_processor_id(void)
872 {
873         S390_lowcore.cpu_nr = 0;
874 }
875
876 /*
877  * the frequency of the profiling timer can be changed
878  * by writing a multiplier value into /proc/profile.
879  *
880  * usually you want to run this on all CPUs ;)
881  */
882 int setup_profiling_timer(unsigned int multiplier)
883 {
884         return 0;
885 }
886
887 #ifdef CONFIG_HOTPLUG_CPU
888 static ssize_t cpu_configure_show(struct device *dev,
889                                   struct device_attribute *attr, char *buf)
890 {
891         ssize_t count;
892
893         mutex_lock(&smp_cpu_state_mutex);
894         count = sprintf(buf, "%d\n", pcpu_devices[dev->id].state);
895         mutex_unlock(&smp_cpu_state_mutex);
896         return count;
897 }
898
899 static ssize_t cpu_configure_store(struct device *dev,
900                                    struct device_attribute *attr,
901                                    const char *buf, size_t count)
902 {
903         struct pcpu *pcpu;
904         int cpu, val, rc;
905         char delim;
906
907         if (sscanf(buf, "%d %c", &val, &delim) != 1)
908                 return -EINVAL;
909         if (val != 0 && val != 1)
910                 return -EINVAL;
911         get_online_cpus();
912         mutex_lock(&smp_cpu_state_mutex);
913         rc = -EBUSY;
914         /* disallow configuration changes of online cpus and cpu 0 */
915         cpu = dev->id;
916         if (cpu_online(cpu) || cpu == 0)
917                 goto out;
918         pcpu = pcpu_devices + cpu;
919         rc = 0;
920         switch (val) {
921         case 0:
922                 if (pcpu->state != CPU_STATE_CONFIGURED)
923                         break;
924                 rc = sclp_cpu_deconfigure(pcpu->address);
925                 if (rc)
926                         break;
927                 pcpu->state = CPU_STATE_STANDBY;
928                 cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
929                 topology_expect_change();
930                 break;
931         case 1:
932                 if (pcpu->state != CPU_STATE_STANDBY)
933                         break;
934                 rc = sclp_cpu_configure(pcpu->address);
935                 if (rc)
936                         break;
937                 pcpu->state = CPU_STATE_CONFIGURED;
938                 cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
939                 topology_expect_change();
940                 break;
941         default:
942                 break;
943         }
944 out:
945         mutex_unlock(&smp_cpu_state_mutex);
946         put_online_cpus();
947         return rc ? rc : count;
948 }
949 static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
950 #endif /* CONFIG_HOTPLUG_CPU */
951
952 static ssize_t show_cpu_address(struct device *dev,
953                                 struct device_attribute *attr, char *buf)
954 {
955         return sprintf(buf, "%d\n", pcpu_devices[dev->id].address);
956 }
957 static DEVICE_ATTR(address, 0444, show_cpu_address, NULL);
958
959 static struct attribute *cpu_common_attrs[] = {
960 #ifdef CONFIG_HOTPLUG_CPU
961         &dev_attr_configure.attr,
962 #endif
963         &dev_attr_address.attr,
964         NULL,
965 };
966
967 static struct attribute_group cpu_common_attr_group = {
968         .attrs = cpu_common_attrs,
969 };
970
971 static ssize_t show_capability(struct device *dev,
972                                 struct device_attribute *attr, char *buf)
973 {
974         unsigned int capability;
975         int rc;
976
977         rc = get_cpu_capability(&capability);
978         if (rc)
979                 return rc;
980         return sprintf(buf, "%u\n", capability);
981 }
982 static DEVICE_ATTR(capability, 0444, show_capability, NULL);
983
984 static ssize_t show_idle_count(struct device *dev,
985                                 struct device_attribute *attr, char *buf)
986 {
987         struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id);
988         unsigned long long idle_count;
989         unsigned int sequence;
990
991         do {
992                 sequence = ACCESS_ONCE(idle->sequence);
993                 idle_count = ACCESS_ONCE(idle->idle_count);
994                 if (ACCESS_ONCE(idle->idle_enter))
995                         idle_count++;
996         } while ((sequence & 1) || (idle->sequence != sequence));
997         return sprintf(buf, "%llu\n", idle_count);
998 }
999 static DEVICE_ATTR(idle_count, 0444, show_idle_count, NULL);
1000
1001 static ssize_t show_idle_time(struct device *dev,
1002                                 struct device_attribute *attr, char *buf)
1003 {
1004         struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id);
1005         unsigned long long now, idle_time, idle_enter, idle_exit;
1006         unsigned int sequence;
1007
1008         do {
1009                 now = get_clock();
1010                 sequence = ACCESS_ONCE(idle->sequence);
1011                 idle_time = ACCESS_ONCE(idle->idle_time);
1012                 idle_enter = ACCESS_ONCE(idle->idle_enter);
1013                 idle_exit = ACCESS_ONCE(idle->idle_exit);
1014         } while ((sequence & 1) || (idle->sequence != sequence));
1015         idle_time += idle_enter ? ((idle_exit ? : now) - idle_enter) : 0;
1016         return sprintf(buf, "%llu\n", idle_time >> 12);
1017 }
1018 static DEVICE_ATTR(idle_time_us, 0444, show_idle_time, NULL);
1019
1020 static struct attribute *cpu_online_attrs[] = {
1021         &dev_attr_capability.attr,
1022         &dev_attr_idle_count.attr,
1023         &dev_attr_idle_time_us.attr,
1024         NULL,
1025 };
1026
1027 static struct attribute_group cpu_online_attr_group = {
1028         .attrs = cpu_online_attrs,
1029 };
1030
1031 static int __cpuinit smp_cpu_notify(struct notifier_block *self,
1032                                     unsigned long action, void *hcpu)
1033 {
1034         unsigned int cpu = (unsigned int)(long)hcpu;
1035         struct cpu *c = &pcpu_devices[cpu].cpu;
1036         struct device *s = &c->dev;
1037         struct s390_idle_data *idle;
1038         int err = 0;
1039
1040         switch (action) {
1041         case CPU_ONLINE:
1042         case CPU_ONLINE_FROZEN:
1043                 idle = &per_cpu(s390_idle, cpu);
1044                 memset(idle, 0, sizeof(struct s390_idle_data));
1045                 err = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
1046                 break;
1047         case CPU_DEAD:
1048         case CPU_DEAD_FROZEN:
1049                 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
1050                 break;
1051         }
1052         return notifier_from_errno(err);
1053 }
1054
1055 static struct notifier_block __cpuinitdata smp_cpu_nb = {
1056         .notifier_call = smp_cpu_notify,
1057 };
1058
1059 static int __devinit smp_add_present_cpu(int cpu)
1060 {
1061         struct cpu *c = &pcpu_devices[cpu].cpu;
1062         struct device *s = &c->dev;
1063         int rc;
1064
1065         c->hotpluggable = 1;
1066         rc = register_cpu(c, cpu);
1067         if (rc)
1068                 goto out;
1069         rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
1070         if (rc)
1071                 goto out_cpu;
1072         if (cpu_online(cpu)) {
1073                 rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
1074                 if (rc)
1075                         goto out_online;
1076         }
1077         rc = topology_cpu_init(c);
1078         if (rc)
1079                 goto out_topology;
1080         return 0;
1081
1082 out_topology:
1083         if (cpu_online(cpu))
1084                 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
1085 out_online:
1086         sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
1087 out_cpu:
1088 #ifdef CONFIG_HOTPLUG_CPU
1089         unregister_cpu(c);
1090 #endif
1091 out:
1092         return rc;
1093 }
1094
1095 #ifdef CONFIG_HOTPLUG_CPU
1096
1097 int __ref smp_rescan_cpus(void)
1098 {
1099         struct sclp_cpu_info *info;
1100         int nr;
1101
1102         info = smp_get_cpu_info();
1103         if (!info)
1104                 return -ENOMEM;
1105         get_online_cpus();
1106         mutex_lock(&smp_cpu_state_mutex);
1107         nr = __smp_rescan_cpus(info, 1);
1108         mutex_unlock(&smp_cpu_state_mutex);
1109         put_online_cpus();
1110         kfree(info);
1111         if (nr)
1112                 topology_schedule_update();
1113         return 0;
1114 }
1115
1116 static ssize_t __ref rescan_store(struct device *dev,
1117                                   struct device_attribute *attr,
1118                                   const char *buf,
1119                                   size_t count)
1120 {
1121         int rc;
1122
1123         rc = smp_rescan_cpus();
1124         return rc ? rc : count;
1125 }
1126 static DEVICE_ATTR(rescan, 0200, NULL, rescan_store);
1127 #endif /* CONFIG_HOTPLUG_CPU */
1128
1129 static int __init s390_smp_init(void)
1130 {
1131         int cpu, rc;
1132
1133         register_cpu_notifier(&smp_cpu_nb);
1134 #ifdef CONFIG_HOTPLUG_CPU
1135         rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan);
1136         if (rc)
1137                 return rc;
1138 #endif
1139         for_each_present_cpu(cpu) {
1140                 rc = smp_add_present_cpu(cpu);
1141                 if (rc)
1142                         return rc;
1143         }
1144         return 0;
1145 }
1146 subsys_initcall(s390_smp_init);