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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * SMP related functions
4 *
5 * Copyright IBM Corp. 1999, 2012
6 * Author(s): Denis Joseph Barrow,
7 * Martin Schwidefsky <schwidefsky@de.ibm.com>,
8 * Heiko Carstens <heiko.carstens@de.ibm.com>,
9 *
10 * based on other smp stuff by
11 * (c) 1995 Alan Cox, CymruNET Ltd <alan@cymru.net>
12 * (c) 1998 Ingo Molnar
13 *
14 * The code outside of smp.c uses logical cpu numbers, only smp.c does
15 * the translation of logical to physical cpu ids. All new code that
16 * operates on physical cpu numbers needs to go into smp.c.
17 */
18
19#define KMSG_COMPONENT "cpu"
20#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
21
22#include <linux/workqueue.h>
23#include <linux/memblock.h>
24#include <linux/export.h>
25#include <linux/init.h>
26#include <linux/mm.h>
27#include <linux/err.h>
28#include <linux/spinlock.h>
29#include <linux/kernel_stat.h>
30#include <linux/delay.h>
31#include <linux/interrupt.h>
32#include <linux/irqflags.h>
33#include <linux/cpu.h>
34#include <linux/slab.h>
35#include <linux/sched/hotplug.h>
36#include <linux/sched/task_stack.h>
37#include <linux/crash_dump.h>
38#include <linux/kprobes.h>
39#include <asm/asm-offsets.h>
40#include <asm/diag.h>
41#include <asm/switch_to.h>
42#include <asm/facility.h>
43#include <asm/ipl.h>
44#include <asm/setup.h>
45#include <asm/irq.h>
46#include <asm/tlbflush.h>
47#include <asm/vtimer.h>
48#include <asm/lowcore.h>
49#include <asm/sclp.h>
50#include <asm/vdso.h>
51#include <asm/debug.h>
52#include <asm/os_info.h>
53#include <asm/sigp.h>
54#include <asm/idle.h>
55#include <asm/nmi.h>
56#include <asm/stacktrace.h>
57#include <asm/topology.h>
58#include "entry.h"
59
60enum {
61 ec_schedule = 0,
62 ec_call_function_single,
63 ec_stop_cpu,
64};
65
66enum {
67 CPU_STATE_STANDBY,
68 CPU_STATE_CONFIGURED,
69};
70
71static DEFINE_PER_CPU(struct cpu *, cpu_device);
72
73struct pcpu {
74 struct lowcore *lowcore; /* lowcore page(s) for the cpu */
75 unsigned long ec_mask; /* bit mask for ec_xxx functions */
76 unsigned long ec_clk; /* sigp timestamp for ec_xxx */
77 signed char state; /* physical cpu state */
78 signed char polarization; /* physical polarization */
79 u16 address; /* physical cpu address */
80};
81
82static u8 boot_core_type;
83static struct pcpu pcpu_devices[NR_CPUS];
84
85unsigned int smp_cpu_mt_shift;
86EXPORT_SYMBOL(smp_cpu_mt_shift);
87
88unsigned int smp_cpu_mtid;
89EXPORT_SYMBOL(smp_cpu_mtid);
90
91#ifdef CONFIG_CRASH_DUMP
92__vector128 __initdata boot_cpu_vector_save_area[__NUM_VXRS];
93#endif
94
95static unsigned int smp_max_threads __initdata = -1U;
96
97static int __init early_nosmt(char *s)
98{
99 smp_max_threads = 1;
100 return 0;
101}
102early_param("nosmt", early_nosmt);
103
104static int __init early_smt(char *s)
105{
106 get_option(&s, &smp_max_threads);
107 return 0;
108}
109early_param("smt", early_smt);
110
111/*
112 * The smp_cpu_state_mutex must be held when changing the state or polarization
113 * member of a pcpu data structure within the pcpu_devices arreay.
114 */
115DEFINE_MUTEX(smp_cpu_state_mutex);
116
117/*
118 * Signal processor helper functions.
119 */
120static inline int __pcpu_sigp_relax(u16 addr, u8 order, unsigned long parm)
121{
122 int cc;
123
124 while (1) {
125 cc = __pcpu_sigp(addr, order, parm, NULL);
126 if (cc != SIGP_CC_BUSY)
127 return cc;
128 cpu_relax();
129 }
130}
131
132static int pcpu_sigp_retry(struct pcpu *pcpu, u8 order, u32 parm)
133{
134 int cc, retry;
135
136 for (retry = 0; ; retry++) {
137 cc = __pcpu_sigp(pcpu->address, order, parm, NULL);
138 if (cc != SIGP_CC_BUSY)
139 break;
140 if (retry >= 3)
141 udelay(10);
142 }
143 return cc;
144}
145
146static inline int pcpu_stopped(struct pcpu *pcpu)
147{
148 u32 uninitialized_var(status);
149
150 if (__pcpu_sigp(pcpu->address, SIGP_SENSE,
151 0, &status) != SIGP_CC_STATUS_STORED)
152 return 0;
153 return !!(status & (SIGP_STATUS_CHECK_STOP|SIGP_STATUS_STOPPED));
154}
155
156static inline int pcpu_running(struct pcpu *pcpu)
157{
158 if (__pcpu_sigp(pcpu->address, SIGP_SENSE_RUNNING,
159 0, NULL) != SIGP_CC_STATUS_STORED)
160 return 1;
161 /* Status stored condition code is equivalent to cpu not running. */
162 return 0;
163}
164
165/*
166 * Find struct pcpu by cpu address.
167 */
168static struct pcpu *pcpu_find_address(const struct cpumask *mask, u16 address)
169{
170 int cpu;
171
172 for_each_cpu(cpu, mask)
173 if (pcpu_devices[cpu].address == address)
174 return pcpu_devices + cpu;
175 return NULL;
176}
177
178static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit)
179{
180 int order;
181
182 if (test_and_set_bit(ec_bit, &pcpu->ec_mask))
183 return;
184 order = pcpu_running(pcpu) ? SIGP_EXTERNAL_CALL : SIGP_EMERGENCY_SIGNAL;
185 pcpu->ec_clk = get_tod_clock_fast();
186 pcpu_sigp_retry(pcpu, order, 0);
187}
188
189static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
190{
191 unsigned long async_stack, nodat_stack;
192 struct lowcore *lc;
193
194 if (pcpu != &pcpu_devices[0]) {
195 pcpu->lowcore = (struct lowcore *)
196 __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
197 nodat_stack = __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
198 if (!pcpu->lowcore || !nodat_stack)
199 goto out;
200 } else {
201 nodat_stack = pcpu->lowcore->nodat_stack - STACK_INIT_OFFSET;
202 }
203 async_stack = stack_alloc();
204 if (!async_stack)
205 goto out;
206 lc = pcpu->lowcore;
207 memcpy(lc, &S390_lowcore, 512);
208 memset((char *) lc + 512, 0, sizeof(*lc) - 512);
209 lc->async_stack = async_stack + STACK_INIT_OFFSET;
210 lc->nodat_stack = nodat_stack + STACK_INIT_OFFSET;
211 lc->cpu_nr = cpu;
212 lc->spinlock_lockval = arch_spin_lockval(cpu);
213 lc->spinlock_index = 0;
214 lc->br_r1_trampoline = 0x07f1; /* br %r1 */
215 if (nmi_alloc_per_cpu(lc))
216 goto out_async;
217 if (vdso_alloc_per_cpu(lc))
218 goto out_mcesa;
219 lowcore_ptr[cpu] = lc;
220 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, (u32)(unsigned long) lc);
221 return 0;
222
223out_mcesa:
224 nmi_free_per_cpu(lc);
225out_async:
226 stack_free(async_stack);
227out:
228 if (pcpu != &pcpu_devices[0]) {
229 free_pages(nodat_stack, THREAD_SIZE_ORDER);
230 free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
231 }
232 return -ENOMEM;
233}
234
235static void pcpu_free_lowcore(struct pcpu *pcpu)
236{
237 unsigned long async_stack, nodat_stack, lowcore;
238
239 nodat_stack = pcpu->lowcore->nodat_stack - STACK_INIT_OFFSET;
240 async_stack = pcpu->lowcore->async_stack - STACK_INIT_OFFSET;
241 lowcore = (unsigned long) pcpu->lowcore;
242
243 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0);
244 lowcore_ptr[pcpu - pcpu_devices] = NULL;
245 vdso_free_per_cpu(pcpu->lowcore);
246 nmi_free_per_cpu(pcpu->lowcore);
247 stack_free(async_stack);
248 if (pcpu == &pcpu_devices[0])
249 return;
250 free_pages(nodat_stack, THREAD_SIZE_ORDER);
251 free_pages(lowcore, LC_ORDER);
252}
253
254static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu)
255{
256 struct lowcore *lc = pcpu->lowcore;
257
258 cpumask_set_cpu(cpu, &init_mm.context.cpu_attach_mask);
259 cpumask_set_cpu(cpu, mm_cpumask(&init_mm));
260 lc->cpu_nr = cpu;
261 lc->spinlock_lockval = arch_spin_lockval(cpu);
262 lc->spinlock_index = 0;
263 lc->percpu_offset = __per_cpu_offset[cpu];
264 lc->kernel_asce = S390_lowcore.kernel_asce;
265 lc->machine_flags = S390_lowcore.machine_flags;
266 lc->user_timer = lc->system_timer =
267 lc->steal_timer = lc->avg_steal_timer = 0;
268 __ctl_store(lc->cregs_save_area, 0, 15);
269 save_access_regs((unsigned int *) lc->access_regs_save_area);
270 memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,
271 sizeof(lc->stfle_fac_list));
272 memcpy(lc->alt_stfle_fac_list, S390_lowcore.alt_stfle_fac_list,
273 sizeof(lc->alt_stfle_fac_list));
274 arch_spin_lock_setup(cpu);
275}
276
277static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk)
278{
279 struct lowcore *lc = pcpu->lowcore;
280
281 lc->kernel_stack = (unsigned long) task_stack_page(tsk)
282 + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
283 lc->current_task = (unsigned long) tsk;
284 lc->lpp = LPP_MAGIC;
285 lc->current_pid = tsk->pid;
286 lc->user_timer = tsk->thread.user_timer;
287 lc->guest_timer = tsk->thread.guest_timer;
288 lc->system_timer = tsk->thread.system_timer;
289 lc->hardirq_timer = tsk->thread.hardirq_timer;
290 lc->softirq_timer = tsk->thread.softirq_timer;
291 lc->steal_timer = 0;
292}
293
294static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data)
295{
296 struct lowcore *lc = pcpu->lowcore;
297
298 lc->restart_stack = lc->nodat_stack;
299 lc->restart_fn = (unsigned long) func;
300 lc->restart_data = (unsigned long) data;
301 lc->restart_source = -1UL;
302 pcpu_sigp_retry(pcpu, SIGP_RESTART, 0);
303}
304
305/*
306 * Call function via PSW restart on pcpu and stop the current cpu.
307 */
308static void __pcpu_delegate(void (*func)(void*), void *data)
309{
310 func(data); /* should not return */
311}
312
313static void __no_sanitize_address pcpu_delegate(struct pcpu *pcpu,
314 void (*func)(void *),
315 void *data, unsigned long stack)
316{
317 struct lowcore *lc = lowcore_ptr[pcpu - pcpu_devices];
318 unsigned long source_cpu = stap();
319
320 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
321 if (pcpu->address == source_cpu)
322 CALL_ON_STACK(__pcpu_delegate, stack, 2, func, data);
323 /* Stop target cpu (if func returns this stops the current cpu). */
324 pcpu_sigp_retry(pcpu, SIGP_STOP, 0);
325 /* Restart func on the target cpu and stop the current cpu. */
326 mem_assign_absolute(lc->restart_stack, stack);
327 mem_assign_absolute(lc->restart_fn, (unsigned long) func);
328 mem_assign_absolute(lc->restart_data, (unsigned long) data);
329 mem_assign_absolute(lc->restart_source, source_cpu);
330 __bpon();
331 asm volatile(
332 "0: sigp 0,%0,%2 # sigp restart to target cpu\n"
333 " brc 2,0b # busy, try again\n"
334 "1: sigp 0,%1,%3 # sigp stop to current cpu\n"
335 " brc 2,1b # busy, try again\n"
336 : : "d" (pcpu->address), "d" (source_cpu),
337 "K" (SIGP_RESTART), "K" (SIGP_STOP)
338 : "0", "1", "cc");
339 for (;;) ;
340}
341
342/*
343 * Enable additional logical cpus for multi-threading.
344 */
345static int pcpu_set_smt(unsigned int mtid)
346{
347 int cc;
348
349 if (smp_cpu_mtid == mtid)
350 return 0;
351 cc = __pcpu_sigp(0, SIGP_SET_MULTI_THREADING, mtid, NULL);
352 if (cc == 0) {
353 smp_cpu_mtid = mtid;
354 smp_cpu_mt_shift = 0;
355 while (smp_cpu_mtid >= (1U << smp_cpu_mt_shift))
356 smp_cpu_mt_shift++;
357 pcpu_devices[0].address = stap();
358 }
359 return cc;
360}
361
362/*
363 * Call function on an online CPU.
364 */
365void smp_call_online_cpu(void (*func)(void *), void *data)
366{
367 struct pcpu *pcpu;
368
369 /* Use the current cpu if it is online. */
370 pcpu = pcpu_find_address(cpu_online_mask, stap());
371 if (!pcpu)
372 /* Use the first online cpu. */
373 pcpu = pcpu_devices + cpumask_first(cpu_online_mask);
374 pcpu_delegate(pcpu, func, data, (unsigned long) restart_stack);
375}
376
377/*
378 * Call function on the ipl CPU.
379 */
380void smp_call_ipl_cpu(void (*func)(void *), void *data)
381{
382 struct lowcore *lc = pcpu_devices->lowcore;
383
384 if (pcpu_devices[0].address == stap())
385 lc = &S390_lowcore;
386
387 pcpu_delegate(&pcpu_devices[0], func, data,
388 lc->nodat_stack);
389}
390
391int smp_find_processor_id(u16 address)
392{
393 int cpu;
394
395 for_each_present_cpu(cpu)
396 if (pcpu_devices[cpu].address == address)
397 return cpu;
398 return -1;
399}
400
401bool arch_vcpu_is_preempted(int cpu)
402{
403 if (test_cpu_flag_of(CIF_ENABLED_WAIT, cpu))
404 return false;
405 if (pcpu_running(pcpu_devices + cpu))
406 return false;
407 return true;
408}
409EXPORT_SYMBOL(arch_vcpu_is_preempted);
410
411void smp_yield_cpu(int cpu)
412{
413 if (MACHINE_HAS_DIAG9C) {
414 diag_stat_inc_norecursion(DIAG_STAT_X09C);
415 asm volatile("diag %0,0,0x9c"
416 : : "d" (pcpu_devices[cpu].address));
417 } else if (MACHINE_HAS_DIAG44 && !smp_cpu_mtid) {
418 diag_stat_inc_norecursion(DIAG_STAT_X044);
419 asm volatile("diag 0,0,0x44");
420 }
421}
422
423/*
424 * Send cpus emergency shutdown signal. This gives the cpus the
425 * opportunity to complete outstanding interrupts.
426 */
427void notrace smp_emergency_stop(void)
428{
429 cpumask_t cpumask;
430 u64 end;
431 int cpu;
432
433 cpumask_copy(&cpumask, cpu_online_mask);
434 cpumask_clear_cpu(smp_processor_id(), &cpumask);
435
436 end = get_tod_clock() + (1000000UL << 12);
437 for_each_cpu(cpu, &cpumask) {
438 struct pcpu *pcpu = pcpu_devices + cpu;
439 set_bit(ec_stop_cpu, &pcpu->ec_mask);
440 while (__pcpu_sigp(pcpu->address, SIGP_EMERGENCY_SIGNAL,
441 0, NULL) == SIGP_CC_BUSY &&
442 get_tod_clock() < end)
443 cpu_relax();
444 }
445 while (get_tod_clock() < end) {
446 for_each_cpu(cpu, &cpumask)
447 if (pcpu_stopped(pcpu_devices + cpu))
448 cpumask_clear_cpu(cpu, &cpumask);
449 if (cpumask_empty(&cpumask))
450 break;
451 cpu_relax();
452 }
453}
454NOKPROBE_SYMBOL(smp_emergency_stop);
455
456/*
457 * Stop all cpus but the current one.
458 */
459void smp_send_stop(void)
460{
461 int cpu;
462
463 /* Disable all interrupts/machine checks */
464 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
465 trace_hardirqs_off();
466
467 debug_set_critical();
468
469 if (oops_in_progress)
470 smp_emergency_stop();
471
472 /* stop all processors */
473 for_each_online_cpu(cpu) {
474 if (cpu == smp_processor_id())
475 continue;
476 pcpu_sigp_retry(pcpu_devices + cpu, SIGP_STOP, 0);
477 while (!pcpu_stopped(pcpu_devices + cpu))
478 cpu_relax();
479 }
480}
481
482/*
483 * This is the main routine where commands issued by other
484 * cpus are handled.
485 */
486static void smp_handle_ext_call(void)
487{
488 unsigned long bits;
489
490 /* handle bit signal external calls */
491 bits = xchg(&pcpu_devices[smp_processor_id()].ec_mask, 0);
492 if (test_bit(ec_stop_cpu, &bits))
493 smp_stop_cpu();
494 if (test_bit(ec_schedule, &bits))
495 scheduler_ipi();
496 if (test_bit(ec_call_function_single, &bits))
497 generic_smp_call_function_single_interrupt();
498}
499
500static void do_ext_call_interrupt(struct ext_code ext_code,
501 unsigned int param32, unsigned long param64)
502{
503 inc_irq_stat(ext_code.code == 0x1202 ? IRQEXT_EXC : IRQEXT_EMS);
504 smp_handle_ext_call();
505}
506
507void arch_send_call_function_ipi_mask(const struct cpumask *mask)
508{
509 int cpu;
510
511 for_each_cpu(cpu, mask)
512 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
513}
514
515void arch_send_call_function_single_ipi(int cpu)
516{
517 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
518}
519
520/*
521 * this function sends a 'reschedule' IPI to another CPU.
522 * it goes straight through and wastes no time serializing
523 * anything. Worst case is that we lose a reschedule ...
524 */
525void smp_send_reschedule(int cpu)
526{
527 pcpu_ec_call(pcpu_devices + cpu, ec_schedule);
528}
529
530/*
531 * parameter area for the set/clear control bit callbacks
532 */
533struct ec_creg_mask_parms {
534 unsigned long orval;
535 unsigned long andval;
536 int cr;
537};
538
539/*
540 * callback for setting/clearing control bits
541 */
542static void smp_ctl_bit_callback(void *info)
543{
544 struct ec_creg_mask_parms *pp = info;
545 unsigned long cregs[16];
546
547 __ctl_store(cregs, 0, 15);
548 cregs[pp->cr] = (cregs[pp->cr] & pp->andval) | pp->orval;
549 __ctl_load(cregs, 0, 15);
550}
551
552/*
553 * Set a bit in a control register of all cpus
554 */
555void smp_ctl_set_bit(int cr, int bit)
556{
557 struct ec_creg_mask_parms parms = { 1UL << bit, -1UL, cr };
558
559 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
560}
561EXPORT_SYMBOL(smp_ctl_set_bit);
562
563/*
564 * Clear a bit in a control register of all cpus
565 */
566void smp_ctl_clear_bit(int cr, int bit)
567{
568 struct ec_creg_mask_parms parms = { 0, ~(1UL << bit), cr };
569
570 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
571}
572EXPORT_SYMBOL(smp_ctl_clear_bit);
573
574#ifdef CONFIG_CRASH_DUMP
575
576int smp_store_status(int cpu)
577{
578 struct pcpu *pcpu = pcpu_devices + cpu;
579 unsigned long pa;
580
581 pa = __pa(&pcpu->lowcore->floating_pt_save_area);
582 if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_STATUS_AT_ADDRESS,
583 pa) != SIGP_CC_ORDER_CODE_ACCEPTED)
584 return -EIO;
585 if (!MACHINE_HAS_VX && !MACHINE_HAS_GS)
586 return 0;
587 pa = __pa(pcpu->lowcore->mcesad & MCESA_ORIGIN_MASK);
588 if (MACHINE_HAS_GS)
589 pa |= pcpu->lowcore->mcesad & MCESA_LC_MASK;
590 if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_ADDITIONAL_STATUS,
591 pa) != SIGP_CC_ORDER_CODE_ACCEPTED)
592 return -EIO;
593 return 0;
594}
595
596/*
597 * Collect CPU state of the previous, crashed system.
598 * There are four cases:
599 * 1) standard zfcp dump
600 * condition: OLDMEM_BASE == NULL && ipl_info.type == IPL_TYPE_FCP_DUMP
601 * The state for all CPUs except the boot CPU needs to be collected
602 * with sigp stop-and-store-status. The boot CPU state is located in
603 * the absolute lowcore of the memory stored in the HSA. The zcore code
604 * will copy the boot CPU state from the HSA.
605 * 2) stand-alone kdump for SCSI (zfcp dump with swapped memory)
606 * condition: OLDMEM_BASE != NULL && ipl_info.type == IPL_TYPE_FCP_DUMP
607 * The state for all CPUs except the boot CPU needs to be collected
608 * with sigp stop-and-store-status. The firmware or the boot-loader
609 * stored the registers of the boot CPU in the absolute lowcore in the
610 * memory of the old system.
611 * 3) kdump and the old kernel did not store the CPU state,
612 * or stand-alone kdump for DASD
613 * condition: OLDMEM_BASE != NULL && !is_kdump_kernel()
614 * The state for all CPUs except the boot CPU needs to be collected
615 * with sigp stop-and-store-status. The kexec code or the boot-loader
616 * stored the registers of the boot CPU in the memory of the old system.
617 * 4) kdump and the old kernel stored the CPU state
618 * condition: OLDMEM_BASE != NULL && is_kdump_kernel()
619 * This case does not exist for s390 anymore, setup_arch explicitly
620 * deactivates the elfcorehdr= kernel parameter
621 */
622static __init void smp_save_cpu_vxrs(struct save_area *sa, u16 addr,
623 bool is_boot_cpu, unsigned long page)
624{
625 __vector128 *vxrs = (__vector128 *) page;
626
627 if (is_boot_cpu)
628 vxrs = boot_cpu_vector_save_area;
629 else
630 __pcpu_sigp_relax(addr, SIGP_STORE_ADDITIONAL_STATUS, page);
631 save_area_add_vxrs(sa, vxrs);
632}
633
634static __init void smp_save_cpu_regs(struct save_area *sa, u16 addr,
635 bool is_boot_cpu, unsigned long page)
636{
637 void *regs = (void *) page;
638
639 if (is_boot_cpu)
640 copy_oldmem_kernel(regs, (void *) __LC_FPREGS_SAVE_AREA, 512);
641 else
642 __pcpu_sigp_relax(addr, SIGP_STORE_STATUS_AT_ADDRESS, page);
643 save_area_add_regs(sa, regs);
644}
645
646void __init smp_save_dump_cpus(void)
647{
648 int addr, boot_cpu_addr, max_cpu_addr;
649 struct save_area *sa;
650 unsigned long page;
651 bool is_boot_cpu;
652
653 if (!(OLDMEM_BASE || ipl_info.type == IPL_TYPE_FCP_DUMP))
654 /* No previous system present, normal boot. */
655 return;
656 /* Allocate a page as dumping area for the store status sigps */
657 page = memblock_phys_alloc_range(PAGE_SIZE, PAGE_SIZE, 0, 1UL << 31);
658 if (!page)
659 panic("ERROR: Failed to allocate %lx bytes below %lx\n",
660 PAGE_SIZE, 1UL << 31);
661
662 /* Set multi-threading state to the previous system. */
663 pcpu_set_smt(sclp.mtid_prev);
664 boot_cpu_addr = stap();
665 max_cpu_addr = SCLP_MAX_CORES << sclp.mtid_prev;
666 for (addr = 0; addr <= max_cpu_addr; addr++) {
667 if (__pcpu_sigp_relax(addr, SIGP_SENSE, 0) ==
668 SIGP_CC_NOT_OPERATIONAL)
669 continue;
670 is_boot_cpu = (addr == boot_cpu_addr);
671 /* Allocate save area */
672 sa = save_area_alloc(is_boot_cpu);
673 if (!sa)
674 panic("could not allocate memory for save area\n");
675 if (MACHINE_HAS_VX)
676 /* Get the vector registers */
677 smp_save_cpu_vxrs(sa, addr, is_boot_cpu, page);
678 /*
679 * For a zfcp dump OLDMEM_BASE == NULL and the registers
680 * of the boot CPU are stored in the HSA. To retrieve
681 * these registers an SCLP request is required which is
682 * done by drivers/s390/char/zcore.c:init_cpu_info()
683 */
684 if (!is_boot_cpu || OLDMEM_BASE)
685 /* Get the CPU registers */
686 smp_save_cpu_regs(sa, addr, is_boot_cpu, page);
687 }
688 memblock_free(page, PAGE_SIZE);
689 diag_dma_ops.diag308_reset();
690 pcpu_set_smt(0);
691}
692#endif /* CONFIG_CRASH_DUMP */
693
694void smp_cpu_set_polarization(int cpu, int val)
695{
696 pcpu_devices[cpu].polarization = val;
697}
698
699int smp_cpu_get_polarization(int cpu)
700{
701 return pcpu_devices[cpu].polarization;
702}
703
704static void __ref smp_get_core_info(struct sclp_core_info *info, int early)
705{
706 static int use_sigp_detection;
707 int address;
708
709 if (use_sigp_detection || sclp_get_core_info(info, early)) {
710 use_sigp_detection = 1;
711 for (address = 0;
712 address < (SCLP_MAX_CORES << smp_cpu_mt_shift);
713 address += (1U << smp_cpu_mt_shift)) {
714 if (__pcpu_sigp_relax(address, SIGP_SENSE, 0) ==
715 SIGP_CC_NOT_OPERATIONAL)
716 continue;
717 info->core[info->configured].core_id =
718 address >> smp_cpu_mt_shift;
719 info->configured++;
720 }
721 info->combined = info->configured;
722 }
723}
724
725static int smp_add_present_cpu(int cpu);
726
727static int __smp_rescan_cpus(struct sclp_core_info *info, int sysfs_add)
728{
729 struct pcpu *pcpu;
730 cpumask_t avail;
731 int cpu, nr, i, j;
732 u16 address;
733
734 nr = 0;
735 cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask);
736 cpu = cpumask_first(&avail);
737 for (i = 0; (i < info->combined) && (cpu < nr_cpu_ids); i++) {
738 if (sclp.has_core_type && info->core[i].type != boot_core_type)
739 continue;
740 address = info->core[i].core_id << smp_cpu_mt_shift;
741 for (j = 0; j <= smp_cpu_mtid; j++) {
742 if (pcpu_find_address(cpu_present_mask, address + j))
743 continue;
744 pcpu = pcpu_devices + cpu;
745 pcpu->address = address + j;
746 pcpu->state =
747 (cpu >= info->configured*(smp_cpu_mtid + 1)) ?
748 CPU_STATE_STANDBY : CPU_STATE_CONFIGURED;
749 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
750 set_cpu_present(cpu, true);
751 if (sysfs_add && smp_add_present_cpu(cpu) != 0)
752 set_cpu_present(cpu, false);
753 else
754 nr++;
755 cpu = cpumask_next(cpu, &avail);
756 if (cpu >= nr_cpu_ids)
757 break;
758 }
759 }
760 return nr;
761}
762
763void __init smp_detect_cpus(void)
764{
765 unsigned int cpu, mtid, c_cpus, s_cpus;
766 struct sclp_core_info *info;
767 u16 address;
768
769 /* Get CPU information */
770 info = memblock_alloc(sizeof(*info), 8);
771 if (!info)
772 panic("%s: Failed to allocate %zu bytes align=0x%x\n",
773 __func__, sizeof(*info), 8);
774 smp_get_core_info(info, 1);
775 /* Find boot CPU type */
776 if (sclp.has_core_type) {
777 address = stap();
778 for (cpu = 0; cpu < info->combined; cpu++)
779 if (info->core[cpu].core_id == address) {
780 /* The boot cpu dictates the cpu type. */
781 boot_core_type = info->core[cpu].type;
782 break;
783 }
784 if (cpu >= info->combined)
785 panic("Could not find boot CPU type");
786 }
787
788 /* Set multi-threading state for the current system */
789 mtid = boot_core_type ? sclp.mtid : sclp.mtid_cp;
790 mtid = (mtid < smp_max_threads) ? mtid : smp_max_threads - 1;
791 pcpu_set_smt(mtid);
792
793 /* Print number of CPUs */
794 c_cpus = s_cpus = 0;
795 for (cpu = 0; cpu < info->combined; cpu++) {
796 if (sclp.has_core_type &&
797 info->core[cpu].type != boot_core_type)
798 continue;
799 if (cpu < info->configured)
800 c_cpus += smp_cpu_mtid + 1;
801 else
802 s_cpus += smp_cpu_mtid + 1;
803 }
804 pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
805
806 /* Add CPUs present at boot */
807 get_online_cpus();
808 __smp_rescan_cpus(info, 0);
809 put_online_cpus();
810 memblock_free_early((unsigned long)info, sizeof(*info));
811}
812
813static void smp_init_secondary(void)
814{
815 int cpu = smp_processor_id();
816
817 S390_lowcore.last_update_clock = get_tod_clock();
818 restore_access_regs(S390_lowcore.access_regs_save_area);
819 cpu_init();
820 preempt_disable();
821 init_cpu_timer();
822 vtime_init();
823 pfault_init();
824 notify_cpu_starting(smp_processor_id());
825 if (topology_cpu_dedicated(cpu))
826 set_cpu_flag(CIF_DEDICATED_CPU);
827 else
828 clear_cpu_flag(CIF_DEDICATED_CPU);
829 set_cpu_online(smp_processor_id(), true);
830 inc_irq_stat(CPU_RST);
831 local_irq_enable();
832 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
833}
834
835/*
836 * Activate a secondary processor.
837 */
838static void __no_sanitize_address smp_start_secondary(void *cpuvoid)
839{
840 S390_lowcore.restart_stack = (unsigned long) restart_stack;
841 S390_lowcore.restart_fn = (unsigned long) do_restart;
842 S390_lowcore.restart_data = 0;
843 S390_lowcore.restart_source = -1UL;
844 __ctl_load(S390_lowcore.cregs_save_area, 0, 15);
845 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
846 CALL_ON_STACK(smp_init_secondary, S390_lowcore.kernel_stack, 0);
847}
848
849/* Upping and downing of CPUs */
850int __cpu_up(unsigned int cpu, struct task_struct *tidle)
851{
852 struct pcpu *pcpu;
853 int base, i, rc;
854
855 pcpu = pcpu_devices + cpu;
856 if (pcpu->state != CPU_STATE_CONFIGURED)
857 return -EIO;
858 base = smp_get_base_cpu(cpu);
859 for (i = 0; i <= smp_cpu_mtid; i++) {
860 if (base + i < nr_cpu_ids)
861 if (cpu_online(base + i))
862 break;
863 }
864 /*
865 * If this is the first CPU of the core to get online
866 * do an initial CPU reset.
867 */
868 if (i > smp_cpu_mtid &&
869 pcpu_sigp_retry(pcpu_devices + base, SIGP_INITIAL_CPU_RESET, 0) !=
870 SIGP_CC_ORDER_CODE_ACCEPTED)
871 return -EIO;
872
873 rc = pcpu_alloc_lowcore(pcpu, cpu);
874 if (rc)
875 return rc;
876 pcpu_prepare_secondary(pcpu, cpu);
877 pcpu_attach_task(pcpu, tidle);
878 pcpu_start_fn(pcpu, smp_start_secondary, NULL);
879 /* Wait until cpu puts itself in the online & active maps */
880 while (!cpu_online(cpu))
881 cpu_relax();
882 return 0;
883}
884
885static unsigned int setup_possible_cpus __initdata;
886
887static int __init _setup_possible_cpus(char *s)
888{
889 get_option(&s, &setup_possible_cpus);
890 return 0;
891}
892early_param("possible_cpus", _setup_possible_cpus);
893
894int __cpu_disable(void)
895{
896 unsigned long cregs[16];
897
898 /* Handle possible pending IPIs */
899 smp_handle_ext_call();
900 set_cpu_online(smp_processor_id(), false);
901 /* Disable pseudo page faults on this cpu. */
902 pfault_fini();
903 /* Disable interrupt sources via control register. */
904 __ctl_store(cregs, 0, 15);
905 cregs[0] &= ~0x0000ee70UL; /* disable all external interrupts */
906 cregs[6] &= ~0xff000000UL; /* disable all I/O interrupts */
907 cregs[14] &= ~0x1f000000UL; /* disable most machine checks */
908 __ctl_load(cregs, 0, 15);
909 clear_cpu_flag(CIF_NOHZ_DELAY);
910 return 0;
911}
912
913void __cpu_die(unsigned int cpu)
914{
915 struct pcpu *pcpu;
916
917 /* Wait until target cpu is down */
918 pcpu = pcpu_devices + cpu;
919 while (!pcpu_stopped(pcpu))
920 cpu_relax();
921 pcpu_free_lowcore(pcpu);
922 cpumask_clear_cpu(cpu, mm_cpumask(&init_mm));
923 cpumask_clear_cpu(cpu, &init_mm.context.cpu_attach_mask);
924}
925
926void __noreturn cpu_die(void)
927{
928 idle_task_exit();
929 __bpon();
930 pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0);
931 for (;;) ;
932}
933
934void __init smp_fill_possible_mask(void)
935{
936 unsigned int possible, sclp_max, cpu;
937
938 sclp_max = max(sclp.mtid, sclp.mtid_cp) + 1;
939 sclp_max = min(smp_max_threads, sclp_max);
940 sclp_max = (sclp.max_cores * sclp_max) ?: nr_cpu_ids;
941 possible = setup_possible_cpus ?: nr_cpu_ids;
942 possible = min(possible, sclp_max);
943 for (cpu = 0; cpu < possible && cpu < nr_cpu_ids; cpu++)
944 set_cpu_possible(cpu, true);
945}
946
947void __init smp_prepare_cpus(unsigned int max_cpus)
948{
949 /* request the 0x1201 emergency signal external interrupt */
950 if (register_external_irq(EXT_IRQ_EMERGENCY_SIG, do_ext_call_interrupt))
951 panic("Couldn't request external interrupt 0x1201");
952 /* request the 0x1202 external call external interrupt */
953 if (register_external_irq(EXT_IRQ_EXTERNAL_CALL, do_ext_call_interrupt))
954 panic("Couldn't request external interrupt 0x1202");
955}
956
957void __init smp_prepare_boot_cpu(void)
958{
959 struct pcpu *pcpu = pcpu_devices;
960
961 WARN_ON(!cpu_present(0) || !cpu_online(0));
962 pcpu->state = CPU_STATE_CONFIGURED;
963 pcpu->lowcore = (struct lowcore *)(unsigned long) store_prefix();
964 S390_lowcore.percpu_offset = __per_cpu_offset[0];
965 smp_cpu_set_polarization(0, POLARIZATION_UNKNOWN);
966}
967
968void __init smp_cpus_done(unsigned int max_cpus)
969{
970}
971
972void __init smp_setup_processor_id(void)
973{
974 pcpu_devices[0].address = stap();
975 S390_lowcore.cpu_nr = 0;
976 S390_lowcore.spinlock_lockval = arch_spin_lockval(0);
977 S390_lowcore.spinlock_index = 0;
978}
979
980/*
981 * the frequency of the profiling timer can be changed
982 * by writing a multiplier value into /proc/profile.
983 *
984 * usually you want to run this on all CPUs ;)
985 */
986int setup_profiling_timer(unsigned int multiplier)
987{
988 return 0;
989}
990
991static ssize_t cpu_configure_show(struct device *dev,
992 struct device_attribute *attr, char *buf)
993{
994 ssize_t count;
995
996 mutex_lock(&smp_cpu_state_mutex);
997 count = sprintf(buf, "%d\n", pcpu_devices[dev->id].state);
998 mutex_unlock(&smp_cpu_state_mutex);
999 return count;
1000}
1001
1002static ssize_t cpu_configure_store(struct device *dev,
1003 struct device_attribute *attr,
1004 const char *buf, size_t count)
1005{
1006 struct pcpu *pcpu;
1007 int cpu, val, rc, i;
1008 char delim;
1009
1010 if (sscanf(buf, "%d %c", &val, &delim) != 1)
1011 return -EINVAL;
1012 if (val != 0 && val != 1)
1013 return -EINVAL;
1014 get_online_cpus();
1015 mutex_lock(&smp_cpu_state_mutex);
1016 rc = -EBUSY;
1017 /* disallow configuration changes of online cpus and cpu 0 */
1018 cpu = dev->id;
1019 cpu = smp_get_base_cpu(cpu);
1020 if (cpu == 0)
1021 goto out;
1022 for (i = 0; i <= smp_cpu_mtid; i++)
1023 if (cpu_online(cpu + i))
1024 goto out;
1025 pcpu = pcpu_devices + cpu;
1026 rc = 0;
1027 switch (val) {
1028 case 0:
1029 if (pcpu->state != CPU_STATE_CONFIGURED)
1030 break;
1031 rc = sclp_core_deconfigure(pcpu->address >> smp_cpu_mt_shift);
1032 if (rc)
1033 break;
1034 for (i = 0; i <= smp_cpu_mtid; i++) {
1035 if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i))
1036 continue;
1037 pcpu[i].state = CPU_STATE_STANDBY;
1038 smp_cpu_set_polarization(cpu + i,
1039 POLARIZATION_UNKNOWN);
1040 }
1041 topology_expect_change();
1042 break;
1043 case 1:
1044 if (pcpu->state != CPU_STATE_STANDBY)
1045 break;
1046 rc = sclp_core_configure(pcpu->address >> smp_cpu_mt_shift);
1047 if (rc)
1048 break;
1049 for (i = 0; i <= smp_cpu_mtid; i++) {
1050 if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i))
1051 continue;
1052 pcpu[i].state = CPU_STATE_CONFIGURED;
1053 smp_cpu_set_polarization(cpu + i,
1054 POLARIZATION_UNKNOWN);
1055 }
1056 topology_expect_change();
1057 break;
1058 default:
1059 break;
1060 }
1061out:
1062 mutex_unlock(&smp_cpu_state_mutex);
1063 put_online_cpus();
1064 return rc ? rc : count;
1065}
1066static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
1067
1068static ssize_t show_cpu_address(struct device *dev,
1069 struct device_attribute *attr, char *buf)
1070{
1071 return sprintf(buf, "%d\n", pcpu_devices[dev->id].address);
1072}
1073static DEVICE_ATTR(address, 0444, show_cpu_address, NULL);
1074
1075static struct attribute *cpu_common_attrs[] = {
1076 &dev_attr_configure.attr,
1077 &dev_attr_address.attr,
1078 NULL,
1079};
1080
1081static struct attribute_group cpu_common_attr_group = {
1082 .attrs = cpu_common_attrs,
1083};
1084
1085static struct attribute *cpu_online_attrs[] = {
1086 &dev_attr_idle_count.attr,
1087 &dev_attr_idle_time_us.attr,
1088 NULL,
1089};
1090
1091static struct attribute_group cpu_online_attr_group = {
1092 .attrs = cpu_online_attrs,
1093};
1094
1095static int smp_cpu_online(unsigned int cpu)
1096{
1097 struct device *s = &per_cpu(cpu_device, cpu)->dev;
1098
1099 return sysfs_create_group(&s->kobj, &cpu_online_attr_group);
1100}
1101static int smp_cpu_pre_down(unsigned int cpu)
1102{
1103 struct device *s = &per_cpu(cpu_device, cpu)->dev;
1104
1105 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
1106 return 0;
1107}
1108
1109static int smp_add_present_cpu(int cpu)
1110{
1111 struct device *s;
1112 struct cpu *c;
1113 int rc;
1114
1115 c = kzalloc(sizeof(*c), GFP_KERNEL);
1116 if (!c)
1117 return -ENOMEM;
1118 per_cpu(cpu_device, cpu) = c;
1119 s = &c->dev;
1120 c->hotpluggable = 1;
1121 rc = register_cpu(c, cpu);
1122 if (rc)
1123 goto out;
1124 rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
1125 if (rc)
1126 goto out_cpu;
1127 rc = topology_cpu_init(c);
1128 if (rc)
1129 goto out_topology;
1130 return 0;
1131
1132out_topology:
1133 sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
1134out_cpu:
1135 unregister_cpu(c);
1136out:
1137 return rc;
1138}
1139
1140int __ref smp_rescan_cpus(void)
1141{
1142 struct sclp_core_info *info;
1143 int nr;
1144
1145 info = kzalloc(sizeof(*info), GFP_KERNEL);
1146 if (!info)
1147 return -ENOMEM;
1148 smp_get_core_info(info, 0);
1149 get_online_cpus();
1150 mutex_lock(&smp_cpu_state_mutex);
1151 nr = __smp_rescan_cpus(info, 1);
1152 mutex_unlock(&smp_cpu_state_mutex);
1153 put_online_cpus();
1154 kfree(info);
1155 if (nr)
1156 topology_schedule_update();
1157 return 0;
1158}
1159
1160static ssize_t __ref rescan_store(struct device *dev,
1161 struct device_attribute *attr,
1162 const char *buf,
1163 size_t count)
1164{
1165 int rc;
1166
1167 rc = lock_device_hotplug_sysfs();
1168 if (rc)
1169 return rc;
1170 rc = smp_rescan_cpus();
1171 unlock_device_hotplug();
1172 return rc ? rc : count;
1173}
1174static DEVICE_ATTR_WO(rescan);
1175
1176static int __init s390_smp_init(void)
1177{
1178 int cpu, rc = 0;
1179
1180 rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan);
1181 if (rc)
1182 return rc;
1183 for_each_present_cpu(cpu) {
1184 rc = smp_add_present_cpu(cpu);
1185 if (rc)
1186 goto out;
1187 }
1188
1189 rc = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "s390/smp:online",
1190 smp_cpu_online, smp_cpu_pre_down);
1191 rc = rc <= 0 ? rc : 0;
1192out:
1193 return rc;
1194}
1195subsys_initcall(s390_smp_init);
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/workqueue.h>
27#include <linux/module.h>
28#include <linux/init.h>
29#include <linux/mm.h>
30#include <linux/err.h>
31#include <linux/spinlock.h>
32#include <linux/kernel_stat.h>
33#include <linux/delay.h>
34#include <linux/cache.h>
35#include <linux/interrupt.h>
36#include <linux/irqflags.h>
37#include <linux/cpu.h>
38#include <linux/timex.h>
39#include <linux/bootmem.h>
40#include <linux/slab.h>
41#include <asm/asm-offsets.h>
42#include <asm/ipl.h>
43#include <asm/setup.h>
44#include <asm/sigp.h>
45#include <asm/pgalloc.h>
46#include <asm/irq.h>
47#include <asm/cpcmd.h>
48#include <asm/tlbflush.h>
49#include <asm/timer.h>
50#include <asm/lowcore.h>
51#include <asm/sclp.h>
52#include <asm/cputime.h>
53#include <asm/vdso.h>
54#include <asm/cpu.h>
55#include "entry.h"
56
57/* logical cpu to cpu address */
58unsigned short __cpu_logical_map[NR_CPUS];
59
60static struct task_struct *current_set[NR_CPUS];
61
62static u8 smp_cpu_type;
63static int smp_use_sigp_detection;
64
65enum s390_cpu_state {
66 CPU_STATE_STANDBY,
67 CPU_STATE_CONFIGURED,
68};
69
70DEFINE_MUTEX(smp_cpu_state_mutex);
71int smp_cpu_polarization[NR_CPUS];
72static int smp_cpu_state[NR_CPUS];
73static int cpu_management;
74
75static DEFINE_PER_CPU(struct cpu, cpu_devices);
76
77static void smp_ext_bitcall(int, int);
78
79static int raw_cpu_stopped(int cpu)
80{
81 u32 status;
82
83 switch (raw_sigp_ps(&status, 0, cpu, sigp_sense)) {
84 case sigp_status_stored:
85 /* Check for stopped and check stop state */
86 if (status & 0x50)
87 return 1;
88 break;
89 default:
90 break;
91 }
92 return 0;
93}
94
95static inline int cpu_stopped(int cpu)
96{
97 return raw_cpu_stopped(cpu_logical_map(cpu));
98}
99
100void smp_switch_to_ipl_cpu(void (*func)(void *), void *data)
101{
102 struct _lowcore *lc, *current_lc;
103 struct stack_frame *sf;
104 struct pt_regs *regs;
105 unsigned long sp;
106
107 if (smp_processor_id() == 0)
108 func(data);
109 __load_psw_mask(PSW_BASE_BITS | PSW_DEFAULT_KEY);
110 /* Disable lowcore protection */
111 __ctl_clear_bit(0, 28);
112 current_lc = lowcore_ptr[smp_processor_id()];
113 lc = lowcore_ptr[0];
114 if (!lc)
115 lc = current_lc;
116 lc->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
117 lc->restart_psw.addr = PSW_ADDR_AMODE | (unsigned long) smp_restart_cpu;
118 if (!cpu_online(0))
119 smp_switch_to_cpu(func, data, 0, stap(), __cpu_logical_map[0]);
120 while (sigp(0, sigp_stop_and_store_status) == sigp_busy)
121 cpu_relax();
122 sp = lc->panic_stack;
123 sp -= sizeof(struct pt_regs);
124 regs = (struct pt_regs *) sp;
125 memcpy(®s->gprs, ¤t_lc->gpregs_save_area, sizeof(regs->gprs));
126 regs->psw = lc->psw_save_area;
127 sp -= STACK_FRAME_OVERHEAD;
128 sf = (struct stack_frame *) sp;
129 sf->back_chain = regs->gprs[15];
130 smp_switch_to_cpu(func, data, sp, stap(), __cpu_logical_map[0]);
131}
132
133void smp_send_stop(void)
134{
135 int cpu, rc;
136
137 /* Disable all interrupts/machine checks */
138 __load_psw_mask(psw_kernel_bits & ~PSW_MASK_MCHECK);
139 trace_hardirqs_off();
140
141 /* stop all processors */
142 for_each_online_cpu(cpu) {
143 if (cpu == smp_processor_id())
144 continue;
145 do {
146 rc = sigp(cpu, sigp_stop);
147 } while (rc == sigp_busy);
148
149 while (!cpu_stopped(cpu))
150 cpu_relax();
151 }
152}
153
154/*
155 * This is the main routine where commands issued by other
156 * cpus are handled.
157 */
158
159static void do_ext_call_interrupt(unsigned int ext_int_code,
160 unsigned int param32, unsigned long param64)
161{
162 unsigned long bits;
163
164 kstat_cpu(smp_processor_id()).irqs[EXTINT_IPI]++;
165 /*
166 * handle bit signal external calls
167 */
168 bits = xchg(&S390_lowcore.ext_call_fast, 0);
169
170 if (test_bit(ec_schedule, &bits))
171 scheduler_ipi();
172
173 if (test_bit(ec_call_function, &bits))
174 generic_smp_call_function_interrupt();
175
176 if (test_bit(ec_call_function_single, &bits))
177 generic_smp_call_function_single_interrupt();
178}
179
180/*
181 * Send an external call sigp to another cpu and return without waiting
182 * for its completion.
183 */
184static void smp_ext_bitcall(int cpu, int sig)
185{
186 /*
187 * Set signaling bit in lowcore of target cpu and kick it
188 */
189 set_bit(sig, (unsigned long *) &lowcore_ptr[cpu]->ext_call_fast);
190 while (sigp(cpu, sigp_emergency_signal) == sigp_busy)
191 udelay(10);
192}
193
194void arch_send_call_function_ipi_mask(const struct cpumask *mask)
195{
196 int cpu;
197
198 for_each_cpu(cpu, mask)
199 smp_ext_bitcall(cpu, ec_call_function);
200}
201
202void arch_send_call_function_single_ipi(int cpu)
203{
204 smp_ext_bitcall(cpu, ec_call_function_single);
205}
206
207#ifndef CONFIG_64BIT
208/*
209 * this function sends a 'purge tlb' signal to another CPU.
210 */
211static void smp_ptlb_callback(void *info)
212{
213 __tlb_flush_local();
214}
215
216void smp_ptlb_all(void)
217{
218 on_each_cpu(smp_ptlb_callback, NULL, 1);
219}
220EXPORT_SYMBOL(smp_ptlb_all);
221#endif /* ! CONFIG_64BIT */
222
223/*
224 * this function sends a 'reschedule' IPI to another CPU.
225 * it goes straight through and wastes no time serializing
226 * anything. Worst case is that we lose a reschedule ...
227 */
228void smp_send_reschedule(int cpu)
229{
230 smp_ext_bitcall(cpu, ec_schedule);
231}
232
233/*
234 * parameter area for the set/clear control bit callbacks
235 */
236struct ec_creg_mask_parms {
237 unsigned long orvals[16];
238 unsigned long andvals[16];
239};
240
241/*
242 * callback for setting/clearing control bits
243 */
244static void smp_ctl_bit_callback(void *info)
245{
246 struct ec_creg_mask_parms *pp = info;
247 unsigned long cregs[16];
248 int i;
249
250 __ctl_store(cregs, 0, 15);
251 for (i = 0; i <= 15; i++)
252 cregs[i] = (cregs[i] & pp->andvals[i]) | pp->orvals[i];
253 __ctl_load(cregs, 0, 15);
254}
255
256/*
257 * Set a bit in a control register of all cpus
258 */
259void smp_ctl_set_bit(int cr, int bit)
260{
261 struct ec_creg_mask_parms parms;
262
263 memset(&parms.orvals, 0, sizeof(parms.orvals));
264 memset(&parms.andvals, 0xff, sizeof(parms.andvals));
265 parms.orvals[cr] = 1UL << bit;
266 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
267}
268EXPORT_SYMBOL(smp_ctl_set_bit);
269
270/*
271 * Clear a bit in a control register of all cpus
272 */
273void smp_ctl_clear_bit(int cr, int bit)
274{
275 struct ec_creg_mask_parms parms;
276
277 memset(&parms.orvals, 0, sizeof(parms.orvals));
278 memset(&parms.andvals, 0xff, sizeof(parms.andvals));
279 parms.andvals[cr] = ~(1UL << bit);
280 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
281}
282EXPORT_SYMBOL(smp_ctl_clear_bit);
283
284#ifdef CONFIG_ZFCPDUMP
285
286static void __init smp_get_save_area(unsigned int cpu, unsigned int phy_cpu)
287{
288 if (ipl_info.type != IPL_TYPE_FCP_DUMP)
289 return;
290 if (cpu >= NR_CPUS) {
291 pr_warning("CPU %i exceeds the maximum %i and is excluded from "
292 "the dump\n", cpu, NR_CPUS - 1);
293 return;
294 }
295 zfcpdump_save_areas[cpu] = kmalloc(sizeof(struct save_area), GFP_KERNEL);
296 while (raw_sigp(phy_cpu, sigp_stop_and_store_status) == sigp_busy)
297 cpu_relax();
298 memcpy_real(zfcpdump_save_areas[cpu],
299 (void *)(unsigned long) store_prefix() + SAVE_AREA_BASE,
300 sizeof(struct save_area));
301}
302
303struct save_area *zfcpdump_save_areas[NR_CPUS + 1];
304EXPORT_SYMBOL_GPL(zfcpdump_save_areas);
305
306#else
307
308static inline void smp_get_save_area(unsigned int cpu, unsigned int phy_cpu) { }
309
310#endif /* CONFIG_ZFCPDUMP */
311
312static int cpu_known(int cpu_id)
313{
314 int cpu;
315
316 for_each_present_cpu(cpu) {
317 if (__cpu_logical_map[cpu] == cpu_id)
318 return 1;
319 }
320 return 0;
321}
322
323static int smp_rescan_cpus_sigp(cpumask_t avail)
324{
325 int cpu_id, logical_cpu;
326
327 logical_cpu = cpumask_first(&avail);
328 if (logical_cpu >= nr_cpu_ids)
329 return 0;
330 for (cpu_id = 0; cpu_id <= MAX_CPU_ADDRESS; cpu_id++) {
331 if (cpu_known(cpu_id))
332 continue;
333 __cpu_logical_map[logical_cpu] = cpu_id;
334 smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN;
335 if (!cpu_stopped(logical_cpu))
336 continue;
337 set_cpu_present(logical_cpu, true);
338 smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
339 logical_cpu = cpumask_next(logical_cpu, &avail);
340 if (logical_cpu >= nr_cpu_ids)
341 break;
342 }
343 return 0;
344}
345
346static int smp_rescan_cpus_sclp(cpumask_t avail)
347{
348 struct sclp_cpu_info *info;
349 int cpu_id, logical_cpu, cpu;
350 int rc;
351
352 logical_cpu = cpumask_first(&avail);
353 if (logical_cpu >= nr_cpu_ids)
354 return 0;
355 info = kmalloc(sizeof(*info), GFP_KERNEL);
356 if (!info)
357 return -ENOMEM;
358 rc = sclp_get_cpu_info(info);
359 if (rc)
360 goto out;
361 for (cpu = 0; cpu < info->combined; cpu++) {
362 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
363 continue;
364 cpu_id = info->cpu[cpu].address;
365 if (cpu_known(cpu_id))
366 continue;
367 __cpu_logical_map[logical_cpu] = cpu_id;
368 smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN;
369 set_cpu_present(logical_cpu, true);
370 if (cpu >= info->configured)
371 smp_cpu_state[logical_cpu] = CPU_STATE_STANDBY;
372 else
373 smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
374 logical_cpu = cpumask_next(logical_cpu, &avail);
375 if (logical_cpu >= nr_cpu_ids)
376 break;
377 }
378out:
379 kfree(info);
380 return rc;
381}
382
383static int __smp_rescan_cpus(void)
384{
385 cpumask_t avail;
386
387 cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask);
388 if (smp_use_sigp_detection)
389 return smp_rescan_cpus_sigp(avail);
390 else
391 return smp_rescan_cpus_sclp(avail);
392}
393
394static void __init smp_detect_cpus(void)
395{
396 unsigned int cpu, c_cpus, s_cpus;
397 struct sclp_cpu_info *info;
398 u16 boot_cpu_addr, cpu_addr;
399
400 c_cpus = 1;
401 s_cpus = 0;
402 boot_cpu_addr = __cpu_logical_map[0];
403 info = kmalloc(sizeof(*info), GFP_KERNEL);
404 if (!info)
405 panic("smp_detect_cpus failed to allocate memory\n");
406 /* Use sigp detection algorithm if sclp doesn't work. */
407 if (sclp_get_cpu_info(info)) {
408 smp_use_sigp_detection = 1;
409 for (cpu = 0; cpu <= MAX_CPU_ADDRESS; cpu++) {
410 if (cpu == boot_cpu_addr)
411 continue;
412 if (!raw_cpu_stopped(cpu))
413 continue;
414 smp_get_save_area(c_cpus, cpu);
415 c_cpus++;
416 }
417 goto out;
418 }
419
420 if (info->has_cpu_type) {
421 for (cpu = 0; cpu < info->combined; cpu++) {
422 if (info->cpu[cpu].address == boot_cpu_addr) {
423 smp_cpu_type = info->cpu[cpu].type;
424 break;
425 }
426 }
427 }
428
429 for (cpu = 0; cpu < info->combined; cpu++) {
430 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
431 continue;
432 cpu_addr = info->cpu[cpu].address;
433 if (cpu_addr == boot_cpu_addr)
434 continue;
435 if (!raw_cpu_stopped(cpu_addr)) {
436 s_cpus++;
437 continue;
438 }
439 smp_get_save_area(c_cpus, cpu_addr);
440 c_cpus++;
441 }
442out:
443 kfree(info);
444 pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
445 get_online_cpus();
446 __smp_rescan_cpus();
447 put_online_cpus();
448}
449
450/*
451 * Activate a secondary processor.
452 */
453int __cpuinit start_secondary(void *cpuvoid)
454{
455 cpu_init();
456 preempt_disable();
457 init_cpu_timer();
458 init_cpu_vtimer();
459 pfault_init();
460
461 notify_cpu_starting(smp_processor_id());
462 ipi_call_lock();
463 set_cpu_online(smp_processor_id(), true);
464 ipi_call_unlock();
465 __ctl_clear_bit(0, 28); /* Disable lowcore protection */
466 S390_lowcore.restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
467 S390_lowcore.restart_psw.addr =
468 PSW_ADDR_AMODE | (unsigned long) psw_restart_int_handler;
469 __ctl_set_bit(0, 28); /* Enable lowcore protection */
470 /*
471 * Wait until the cpu which brought this one up marked it
472 * active before enabling interrupts.
473 */
474 while (!cpumask_test_cpu(smp_processor_id(), cpu_active_mask))
475 cpu_relax();
476 local_irq_enable();
477 /* cpu_idle will call schedule for us */
478 cpu_idle();
479 return 0;
480}
481
482struct create_idle {
483 struct work_struct work;
484 struct task_struct *idle;
485 struct completion done;
486 int cpu;
487};
488
489static void __cpuinit smp_fork_idle(struct work_struct *work)
490{
491 struct create_idle *c_idle;
492
493 c_idle = container_of(work, struct create_idle, work);
494 c_idle->idle = fork_idle(c_idle->cpu);
495 complete(&c_idle->done);
496}
497
498static int __cpuinit smp_alloc_lowcore(int cpu)
499{
500 unsigned long async_stack, panic_stack;
501 struct _lowcore *lowcore;
502
503 lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
504 if (!lowcore)
505 return -ENOMEM;
506 async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
507 panic_stack = __get_free_page(GFP_KERNEL);
508 if (!panic_stack || !async_stack)
509 goto out;
510 memcpy(lowcore, &S390_lowcore, 512);
511 memset((char *)lowcore + 512, 0, sizeof(*lowcore) - 512);
512 lowcore->async_stack = async_stack + ASYNC_SIZE;
513 lowcore->panic_stack = panic_stack + PAGE_SIZE;
514 lowcore->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
515 lowcore->restart_psw.addr =
516 PSW_ADDR_AMODE | (unsigned long) restart_int_handler;
517 if (user_mode != HOME_SPACE_MODE)
518 lowcore->restart_psw.mask |= PSW_ASC_HOME;
519#ifndef CONFIG_64BIT
520 if (MACHINE_HAS_IEEE) {
521 unsigned long save_area;
522
523 save_area = get_zeroed_page(GFP_KERNEL);
524 if (!save_area)
525 goto out;
526 lowcore->extended_save_area_addr = (u32) save_area;
527 }
528#else
529 if (vdso_alloc_per_cpu(cpu, lowcore))
530 goto out;
531#endif
532 lowcore_ptr[cpu] = lowcore;
533 return 0;
534
535out:
536 free_page(panic_stack);
537 free_pages(async_stack, ASYNC_ORDER);
538 free_pages((unsigned long) lowcore, LC_ORDER);
539 return -ENOMEM;
540}
541
542static void smp_free_lowcore(int cpu)
543{
544 struct _lowcore *lowcore;
545
546 lowcore = lowcore_ptr[cpu];
547#ifndef CONFIG_64BIT
548 if (MACHINE_HAS_IEEE)
549 free_page((unsigned long) lowcore->extended_save_area_addr);
550#else
551 vdso_free_per_cpu(cpu, lowcore);
552#endif
553 free_page(lowcore->panic_stack - PAGE_SIZE);
554 free_pages(lowcore->async_stack - ASYNC_SIZE, ASYNC_ORDER);
555 free_pages((unsigned long) lowcore, LC_ORDER);
556 lowcore_ptr[cpu] = NULL;
557}
558
559/* Upping and downing of CPUs */
560int __cpuinit __cpu_up(unsigned int cpu)
561{
562 struct _lowcore *cpu_lowcore;
563 struct create_idle c_idle;
564 struct task_struct *idle;
565 struct stack_frame *sf;
566 u32 lowcore;
567 int ccode;
568
569 if (smp_cpu_state[cpu] != CPU_STATE_CONFIGURED)
570 return -EIO;
571 idle = current_set[cpu];
572 if (!idle) {
573 c_idle.done = COMPLETION_INITIALIZER_ONSTACK(c_idle.done);
574 INIT_WORK_ONSTACK(&c_idle.work, smp_fork_idle);
575 c_idle.cpu = cpu;
576 schedule_work(&c_idle.work);
577 wait_for_completion(&c_idle.done);
578 if (IS_ERR(c_idle.idle))
579 return PTR_ERR(c_idle.idle);
580 idle = c_idle.idle;
581 current_set[cpu] = c_idle.idle;
582 }
583 init_idle(idle, cpu);
584 if (smp_alloc_lowcore(cpu))
585 return -ENOMEM;
586 do {
587 ccode = sigp(cpu, sigp_initial_cpu_reset);
588 if (ccode == sigp_busy)
589 udelay(10);
590 if (ccode == sigp_not_operational)
591 goto err_out;
592 } while (ccode == sigp_busy);
593
594 lowcore = (u32)(unsigned long)lowcore_ptr[cpu];
595 while (sigp_p(lowcore, cpu, sigp_set_prefix) == sigp_busy)
596 udelay(10);
597
598 cpu_lowcore = lowcore_ptr[cpu];
599 cpu_lowcore->kernel_stack = (unsigned long)
600 task_stack_page(idle) + THREAD_SIZE;
601 cpu_lowcore->thread_info = (unsigned long) task_thread_info(idle);
602 sf = (struct stack_frame *) (cpu_lowcore->kernel_stack
603 - sizeof(struct pt_regs)
604 - sizeof(struct stack_frame));
605 memset(sf, 0, sizeof(struct stack_frame));
606 sf->gprs[9] = (unsigned long) sf;
607 cpu_lowcore->save_area[15] = (unsigned long) sf;
608 __ctl_store(cpu_lowcore->cregs_save_area, 0, 15);
609 atomic_inc(&init_mm.context.attach_count);
610 asm volatile(
611 " stam 0,15,0(%0)"
612 : : "a" (&cpu_lowcore->access_regs_save_area) : "memory");
613 cpu_lowcore->percpu_offset = __per_cpu_offset[cpu];
614 cpu_lowcore->current_task = (unsigned long) idle;
615 cpu_lowcore->cpu_nr = cpu;
616 cpu_lowcore->kernel_asce = S390_lowcore.kernel_asce;
617 cpu_lowcore->machine_flags = S390_lowcore.machine_flags;
618 cpu_lowcore->ftrace_func = S390_lowcore.ftrace_func;
619 memcpy(cpu_lowcore->stfle_fac_list, S390_lowcore.stfle_fac_list,
620 MAX_FACILITY_BIT/8);
621 eieio();
622
623 while (sigp(cpu, sigp_restart) == sigp_busy)
624 udelay(10);
625
626 while (!cpu_online(cpu))
627 cpu_relax();
628 return 0;
629
630err_out:
631 smp_free_lowcore(cpu);
632 return -EIO;
633}
634
635static int __init setup_possible_cpus(char *s)
636{
637 int pcpus, cpu;
638
639 pcpus = simple_strtoul(s, NULL, 0);
640 init_cpu_possible(cpumask_of(0));
641 for (cpu = 1; cpu < pcpus && cpu < nr_cpu_ids; cpu++)
642 set_cpu_possible(cpu, true);
643 return 0;
644}
645early_param("possible_cpus", setup_possible_cpus);
646
647#ifdef CONFIG_HOTPLUG_CPU
648
649int __cpu_disable(void)
650{
651 struct ec_creg_mask_parms cr_parms;
652 int cpu = smp_processor_id();
653
654 set_cpu_online(cpu, false);
655
656 /* Disable pfault pseudo page faults on this cpu. */
657 pfault_fini();
658
659 memset(&cr_parms.orvals, 0, sizeof(cr_parms.orvals));
660 memset(&cr_parms.andvals, 0xff, sizeof(cr_parms.andvals));
661
662 /* disable all external interrupts */
663 cr_parms.orvals[0] = 0;
664 cr_parms.andvals[0] = ~(1 << 15 | 1 << 14 | 1 << 13 | 1 << 11 |
665 1 << 10 | 1 << 9 | 1 << 6 | 1 << 5 |
666 1 << 4);
667 /* disable all I/O interrupts */
668 cr_parms.orvals[6] = 0;
669 cr_parms.andvals[6] = ~(1 << 31 | 1 << 30 | 1 << 29 | 1 << 28 |
670 1 << 27 | 1 << 26 | 1 << 25 | 1 << 24);
671 /* disable most machine checks */
672 cr_parms.orvals[14] = 0;
673 cr_parms.andvals[14] = ~(1 << 28 | 1 << 27 | 1 << 26 |
674 1 << 25 | 1 << 24);
675
676 smp_ctl_bit_callback(&cr_parms);
677
678 return 0;
679}
680
681void __cpu_die(unsigned int cpu)
682{
683 /* Wait until target cpu is down */
684 while (!cpu_stopped(cpu))
685 cpu_relax();
686 while (sigp_p(0, cpu, sigp_set_prefix) == sigp_busy)
687 udelay(10);
688 smp_free_lowcore(cpu);
689 atomic_dec(&init_mm.context.attach_count);
690}
691
692void __noreturn cpu_die(void)
693{
694 idle_task_exit();
695 while (sigp(smp_processor_id(), sigp_stop) == sigp_busy)
696 cpu_relax();
697 for (;;);
698}
699
700#endif /* CONFIG_HOTPLUG_CPU */
701
702void __init smp_prepare_cpus(unsigned int max_cpus)
703{
704#ifndef CONFIG_64BIT
705 unsigned long save_area = 0;
706#endif
707 unsigned long async_stack, panic_stack;
708 struct _lowcore *lowcore;
709
710 smp_detect_cpus();
711
712 /* request the 0x1201 emergency signal external interrupt */
713 if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0)
714 panic("Couldn't request external interrupt 0x1201");
715
716 /* Reallocate current lowcore, but keep its contents. */
717 lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
718 panic_stack = __get_free_page(GFP_KERNEL);
719 async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
720 BUG_ON(!lowcore || !panic_stack || !async_stack);
721#ifndef CONFIG_64BIT
722 if (MACHINE_HAS_IEEE)
723 save_area = get_zeroed_page(GFP_KERNEL);
724#endif
725 local_irq_disable();
726 local_mcck_disable();
727 lowcore_ptr[smp_processor_id()] = lowcore;
728 *lowcore = S390_lowcore;
729 lowcore->panic_stack = panic_stack + PAGE_SIZE;
730 lowcore->async_stack = async_stack + ASYNC_SIZE;
731#ifndef CONFIG_64BIT
732 if (MACHINE_HAS_IEEE)
733 lowcore->extended_save_area_addr = (u32) save_area;
734#endif
735 set_prefix((u32)(unsigned long) lowcore);
736 local_mcck_enable();
737 local_irq_enable();
738#ifdef CONFIG_64BIT
739 if (vdso_alloc_per_cpu(smp_processor_id(), &S390_lowcore))
740 BUG();
741#endif
742}
743
744void __init smp_prepare_boot_cpu(void)
745{
746 BUG_ON(smp_processor_id() != 0);
747
748 current_thread_info()->cpu = 0;
749 set_cpu_present(0, true);
750 set_cpu_online(0, true);
751 S390_lowcore.percpu_offset = __per_cpu_offset[0];
752 current_set[0] = current;
753 smp_cpu_state[0] = CPU_STATE_CONFIGURED;
754 smp_cpu_polarization[0] = POLARIZATION_UNKNWN;
755}
756
757void __init smp_cpus_done(unsigned int max_cpus)
758{
759}
760
761void __init smp_setup_processor_id(void)
762{
763 S390_lowcore.cpu_nr = 0;
764 __cpu_logical_map[0] = stap();
765}
766
767/*
768 * the frequency of the profiling timer can be changed
769 * by writing a multiplier value into /proc/profile.
770 *
771 * usually you want to run this on all CPUs ;)
772 */
773int setup_profiling_timer(unsigned int multiplier)
774{
775 return 0;
776}
777
778#ifdef CONFIG_HOTPLUG_CPU
779static ssize_t cpu_configure_show(struct sys_device *dev,
780 struct sysdev_attribute *attr, char *buf)
781{
782 ssize_t count;
783
784 mutex_lock(&smp_cpu_state_mutex);
785 count = sprintf(buf, "%d\n", smp_cpu_state[dev->id]);
786 mutex_unlock(&smp_cpu_state_mutex);
787 return count;
788}
789
790static ssize_t cpu_configure_store(struct sys_device *dev,
791 struct sysdev_attribute *attr,
792 const char *buf, size_t count)
793{
794 int cpu = dev->id;
795 int val, rc;
796 char delim;
797
798 if (sscanf(buf, "%d %c", &val, &delim) != 1)
799 return -EINVAL;
800 if (val != 0 && val != 1)
801 return -EINVAL;
802
803 get_online_cpus();
804 mutex_lock(&smp_cpu_state_mutex);
805 rc = -EBUSY;
806 /* disallow configuration changes of online cpus and cpu 0 */
807 if (cpu_online(cpu) || cpu == 0)
808 goto out;
809 rc = 0;
810 switch (val) {
811 case 0:
812 if (smp_cpu_state[cpu] == CPU_STATE_CONFIGURED) {
813 rc = sclp_cpu_deconfigure(__cpu_logical_map[cpu]);
814 if (!rc) {
815 smp_cpu_state[cpu] = CPU_STATE_STANDBY;
816 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
817 }
818 }
819 break;
820 case 1:
821 if (smp_cpu_state[cpu] == CPU_STATE_STANDBY) {
822 rc = sclp_cpu_configure(__cpu_logical_map[cpu]);
823 if (!rc) {
824 smp_cpu_state[cpu] = CPU_STATE_CONFIGURED;
825 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
826 }
827 }
828 break;
829 default:
830 break;
831 }
832out:
833 mutex_unlock(&smp_cpu_state_mutex);
834 put_online_cpus();
835 return rc ? rc : count;
836}
837static SYSDEV_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
838#endif /* CONFIG_HOTPLUG_CPU */
839
840static ssize_t cpu_polarization_show(struct sys_device *dev,
841 struct sysdev_attribute *attr, char *buf)
842{
843 int cpu = dev->id;
844 ssize_t count;
845
846 mutex_lock(&smp_cpu_state_mutex);
847 switch (smp_cpu_polarization[cpu]) {
848 case POLARIZATION_HRZ:
849 count = sprintf(buf, "horizontal\n");
850 break;
851 case POLARIZATION_VL:
852 count = sprintf(buf, "vertical:low\n");
853 break;
854 case POLARIZATION_VM:
855 count = sprintf(buf, "vertical:medium\n");
856 break;
857 case POLARIZATION_VH:
858 count = sprintf(buf, "vertical:high\n");
859 break;
860 default:
861 count = sprintf(buf, "unknown\n");
862 break;
863 }
864 mutex_unlock(&smp_cpu_state_mutex);
865 return count;
866}
867static SYSDEV_ATTR(polarization, 0444, cpu_polarization_show, NULL);
868
869static ssize_t show_cpu_address(struct sys_device *dev,
870 struct sysdev_attribute *attr, char *buf)
871{
872 return sprintf(buf, "%d\n", __cpu_logical_map[dev->id]);
873}
874static SYSDEV_ATTR(address, 0444, show_cpu_address, NULL);
875
876
877static struct attribute *cpu_common_attrs[] = {
878#ifdef CONFIG_HOTPLUG_CPU
879 &attr_configure.attr,
880#endif
881 &attr_address.attr,
882 &attr_polarization.attr,
883 NULL,
884};
885
886static struct attribute_group cpu_common_attr_group = {
887 .attrs = cpu_common_attrs,
888};
889
890static ssize_t show_capability(struct sys_device *dev,
891 struct sysdev_attribute *attr, char *buf)
892{
893 unsigned int capability;
894 int rc;
895
896 rc = get_cpu_capability(&capability);
897 if (rc)
898 return rc;
899 return sprintf(buf, "%u\n", capability);
900}
901static SYSDEV_ATTR(capability, 0444, show_capability, NULL);
902
903static ssize_t show_idle_count(struct sys_device *dev,
904 struct sysdev_attribute *attr, char *buf)
905{
906 struct s390_idle_data *idle;
907 unsigned long long idle_count;
908 unsigned int sequence;
909
910 idle = &per_cpu(s390_idle, dev->id);
911repeat:
912 sequence = idle->sequence;
913 smp_rmb();
914 if (sequence & 1)
915 goto repeat;
916 idle_count = idle->idle_count;
917 if (idle->idle_enter)
918 idle_count++;
919 smp_rmb();
920 if (idle->sequence != sequence)
921 goto repeat;
922 return sprintf(buf, "%llu\n", idle_count);
923}
924static SYSDEV_ATTR(idle_count, 0444, show_idle_count, NULL);
925
926static ssize_t show_idle_time(struct sys_device *dev,
927 struct sysdev_attribute *attr, char *buf)
928{
929 struct s390_idle_data *idle;
930 unsigned long long now, idle_time, idle_enter;
931 unsigned int sequence;
932
933 idle = &per_cpu(s390_idle, dev->id);
934 now = get_clock();
935repeat:
936 sequence = idle->sequence;
937 smp_rmb();
938 if (sequence & 1)
939 goto repeat;
940 idle_time = idle->idle_time;
941 idle_enter = idle->idle_enter;
942 if (idle_enter != 0ULL && idle_enter < now)
943 idle_time += now - idle_enter;
944 smp_rmb();
945 if (idle->sequence != sequence)
946 goto repeat;
947 return sprintf(buf, "%llu\n", idle_time >> 12);
948}
949static SYSDEV_ATTR(idle_time_us, 0444, show_idle_time, NULL);
950
951static struct attribute *cpu_online_attrs[] = {
952 &attr_capability.attr,
953 &attr_idle_count.attr,
954 &attr_idle_time_us.attr,
955 NULL,
956};
957
958static struct attribute_group cpu_online_attr_group = {
959 .attrs = cpu_online_attrs,
960};
961
962static int __cpuinit smp_cpu_notify(struct notifier_block *self,
963 unsigned long action, void *hcpu)
964{
965 unsigned int cpu = (unsigned int)(long)hcpu;
966 struct cpu *c = &per_cpu(cpu_devices, cpu);
967 struct sys_device *s = &c->sysdev;
968 struct s390_idle_data *idle;
969 int err = 0;
970
971 switch (action) {
972 case CPU_ONLINE:
973 case CPU_ONLINE_FROZEN:
974 idle = &per_cpu(s390_idle, cpu);
975 memset(idle, 0, sizeof(struct s390_idle_data));
976 err = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
977 break;
978 case CPU_DEAD:
979 case CPU_DEAD_FROZEN:
980 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
981 break;
982 }
983 return notifier_from_errno(err);
984}
985
986static struct notifier_block __cpuinitdata smp_cpu_nb = {
987 .notifier_call = smp_cpu_notify,
988};
989
990static int __devinit smp_add_present_cpu(int cpu)
991{
992 struct cpu *c = &per_cpu(cpu_devices, cpu);
993 struct sys_device *s = &c->sysdev;
994 int rc;
995
996 c->hotpluggable = 1;
997 rc = register_cpu(c, cpu);
998 if (rc)
999 goto out;
1000 rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
1001 if (rc)
1002 goto out_cpu;
1003 if (!cpu_online(cpu))
1004 goto out;
1005 rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
1006 if (!rc)
1007 return 0;
1008 sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
1009out_cpu:
1010#ifdef CONFIG_HOTPLUG_CPU
1011 unregister_cpu(c);
1012#endif
1013out:
1014 return rc;
1015}
1016
1017#ifdef CONFIG_HOTPLUG_CPU
1018
1019int __ref smp_rescan_cpus(void)
1020{
1021 cpumask_t newcpus;
1022 int cpu;
1023 int rc;
1024
1025 get_online_cpus();
1026 mutex_lock(&smp_cpu_state_mutex);
1027 cpumask_copy(&newcpus, cpu_present_mask);
1028 rc = __smp_rescan_cpus();
1029 if (rc)
1030 goto out;
1031 cpumask_andnot(&newcpus, cpu_present_mask, &newcpus);
1032 for_each_cpu(cpu, &newcpus) {
1033 rc = smp_add_present_cpu(cpu);
1034 if (rc)
1035 set_cpu_present(cpu, false);
1036 }
1037 rc = 0;
1038out:
1039 mutex_unlock(&smp_cpu_state_mutex);
1040 put_online_cpus();
1041 if (!cpumask_empty(&newcpus))
1042 topology_schedule_update();
1043 return rc;
1044}
1045
1046static ssize_t __ref rescan_store(struct sysdev_class *class,
1047 struct sysdev_class_attribute *attr,
1048 const char *buf,
1049 size_t count)
1050{
1051 int rc;
1052
1053 rc = smp_rescan_cpus();
1054 return rc ? rc : count;
1055}
1056static SYSDEV_CLASS_ATTR(rescan, 0200, NULL, rescan_store);
1057#endif /* CONFIG_HOTPLUG_CPU */
1058
1059static ssize_t dispatching_show(struct sysdev_class *class,
1060 struct sysdev_class_attribute *attr,
1061 char *buf)
1062{
1063 ssize_t count;
1064
1065 mutex_lock(&smp_cpu_state_mutex);
1066 count = sprintf(buf, "%d\n", cpu_management);
1067 mutex_unlock(&smp_cpu_state_mutex);
1068 return count;
1069}
1070
1071static ssize_t dispatching_store(struct sysdev_class *dev,
1072 struct sysdev_class_attribute *attr,
1073 const char *buf,
1074 size_t count)
1075{
1076 int val, rc;
1077 char delim;
1078
1079 if (sscanf(buf, "%d %c", &val, &delim) != 1)
1080 return -EINVAL;
1081 if (val != 0 && val != 1)
1082 return -EINVAL;
1083 rc = 0;
1084 get_online_cpus();
1085 mutex_lock(&smp_cpu_state_mutex);
1086 if (cpu_management == val)
1087 goto out;
1088 rc = topology_set_cpu_management(val);
1089 if (!rc)
1090 cpu_management = val;
1091out:
1092 mutex_unlock(&smp_cpu_state_mutex);
1093 put_online_cpus();
1094 return rc ? rc : count;
1095}
1096static SYSDEV_CLASS_ATTR(dispatching, 0644, dispatching_show,
1097 dispatching_store);
1098
1099static int __init topology_init(void)
1100{
1101 int cpu;
1102 int rc;
1103
1104 register_cpu_notifier(&smp_cpu_nb);
1105
1106#ifdef CONFIG_HOTPLUG_CPU
1107 rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_rescan);
1108 if (rc)
1109 return rc;
1110#endif
1111 rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_dispatching);
1112 if (rc)
1113 return rc;
1114 for_each_present_cpu(cpu) {
1115 rc = smp_add_present_cpu(cpu);
1116 if (rc)
1117 return rc;
1118 }
1119 return 0;
1120}
1121subsys_initcall(topology_init);