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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 *
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/memblock.h>
23#include <linux/export.h>
24#include <linux/init.h>
25#include <linux/mm.h>
26#include <linux/err.h>
27#include <linux/spinlock.h>
28#include <linux/kernel_stat.h>
29#include <linux/delay.h>
30#include <linux/interrupt.h>
31#include <linux/irqflags.h>
32#include <linux/irq_work.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/ctlreg.h>
41#include <asm/pfault.h>
42#include <asm/diag.h>
43#include <asm/switch_to.h>
44#include <asm/facility.h>
45#include <asm/ipl.h>
46#include <asm/setup.h>
47#include <asm/irq.h>
48#include <asm/tlbflush.h>
49#include <asm/vtimer.h>
50#include <asm/abs_lowcore.h>
51#include <asm/sclp.h>
52#include <asm/debug.h>
53#include <asm/os_info.h>
54#include <asm/sigp.h>
55#include <asm/idle.h>
56#include <asm/nmi.h>
57#include <asm/stacktrace.h>
58#include <asm/topology.h>
59#include <asm/vdso.h>
60#include <asm/maccess.h>
61#include "entry.h"
62
63enum {
64 ec_schedule = 0,
65 ec_call_function_single,
66 ec_stop_cpu,
67 ec_mcck_pending,
68 ec_irq_work,
69};
70
71enum {
72 CPU_STATE_STANDBY,
73 CPU_STATE_CONFIGURED,
74};
75
76static DEFINE_PER_CPU(struct cpu *, cpu_device);
77
78struct pcpu {
79 unsigned long ec_mask; /* bit mask for ec_xxx functions */
80 unsigned long ec_clk; /* sigp timestamp for ec_xxx */
81 signed char state; /* physical cpu state */
82 signed char polarization; /* physical polarization */
83 u16 address; /* physical cpu address */
84};
85
86static u8 boot_core_type;
87static struct pcpu pcpu_devices[NR_CPUS];
88
89unsigned int smp_cpu_mt_shift;
90EXPORT_SYMBOL(smp_cpu_mt_shift);
91
92unsigned int smp_cpu_mtid;
93EXPORT_SYMBOL(smp_cpu_mtid);
94
95#ifdef CONFIG_CRASH_DUMP
96__vector128 __initdata boot_cpu_vector_save_area[__NUM_VXRS];
97#endif
98
99static unsigned int smp_max_threads __initdata = -1U;
100cpumask_t cpu_setup_mask;
101
102static int __init early_nosmt(char *s)
103{
104 smp_max_threads = 1;
105 return 0;
106}
107early_param("nosmt", early_nosmt);
108
109static int __init early_smt(char *s)
110{
111 get_option(&s, &smp_max_threads);
112 return 0;
113}
114early_param("smt", early_smt);
115
116/*
117 * The smp_cpu_state_mutex must be held when changing the state or polarization
118 * member of a pcpu data structure within the pcpu_devices array.
119 */
120DEFINE_MUTEX(smp_cpu_state_mutex);
121
122/*
123 * Signal processor helper functions.
124 */
125static inline int __pcpu_sigp_relax(u16 addr, u8 order, unsigned long parm)
126{
127 int cc;
128
129 while (1) {
130 cc = __pcpu_sigp(addr, order, parm, NULL);
131 if (cc != SIGP_CC_BUSY)
132 return cc;
133 cpu_relax();
134 }
135}
136
137static int pcpu_sigp_retry(struct pcpu *pcpu, u8 order, u32 parm)
138{
139 int cc, retry;
140
141 for (retry = 0; ; retry++) {
142 cc = __pcpu_sigp(pcpu->address, order, parm, NULL);
143 if (cc != SIGP_CC_BUSY)
144 break;
145 if (retry >= 3)
146 udelay(10);
147 }
148 return cc;
149}
150
151static inline int pcpu_stopped(struct pcpu *pcpu)
152{
153 u32 status;
154
155 if (__pcpu_sigp(pcpu->address, SIGP_SENSE,
156 0, &status) != SIGP_CC_STATUS_STORED)
157 return 0;
158 return !!(status & (SIGP_STATUS_CHECK_STOP|SIGP_STATUS_STOPPED));
159}
160
161static inline int pcpu_running(struct pcpu *pcpu)
162{
163 if (__pcpu_sigp(pcpu->address, SIGP_SENSE_RUNNING,
164 0, NULL) != SIGP_CC_STATUS_STORED)
165 return 1;
166 /* Status stored condition code is equivalent to cpu not running. */
167 return 0;
168}
169
170/*
171 * Find struct pcpu by cpu address.
172 */
173static struct pcpu *pcpu_find_address(const struct cpumask *mask, u16 address)
174{
175 int cpu;
176
177 for_each_cpu(cpu, mask)
178 if (pcpu_devices[cpu].address == address)
179 return pcpu_devices + cpu;
180 return NULL;
181}
182
183static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit)
184{
185 int order;
186
187 if (test_and_set_bit(ec_bit, &pcpu->ec_mask))
188 return;
189 order = pcpu_running(pcpu) ? SIGP_EXTERNAL_CALL : SIGP_EMERGENCY_SIGNAL;
190 pcpu->ec_clk = get_tod_clock_fast();
191 pcpu_sigp_retry(pcpu, order, 0);
192}
193
194static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
195{
196 unsigned long async_stack, nodat_stack, mcck_stack;
197 struct lowcore *lc;
198
199 lc = (struct lowcore *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
200 nodat_stack = __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
201 async_stack = stack_alloc();
202 mcck_stack = stack_alloc();
203 if (!lc || !nodat_stack || !async_stack || !mcck_stack)
204 goto out;
205 memcpy(lc, &S390_lowcore, 512);
206 memset((char *) lc + 512, 0, sizeof(*lc) - 512);
207 lc->async_stack = async_stack + STACK_INIT_OFFSET;
208 lc->nodat_stack = nodat_stack + STACK_INIT_OFFSET;
209 lc->mcck_stack = mcck_stack + STACK_INIT_OFFSET;
210 lc->cpu_nr = cpu;
211 lc->spinlock_lockval = arch_spin_lockval(cpu);
212 lc->spinlock_index = 0;
213 lc->return_lpswe = gen_lpswe(__LC_RETURN_PSW);
214 lc->return_mcck_lpswe = gen_lpswe(__LC_RETURN_MCCK_PSW);
215 lc->preempt_count = PREEMPT_DISABLED;
216 if (nmi_alloc_mcesa(&lc->mcesad))
217 goto out;
218 if (abs_lowcore_map(cpu, lc, true))
219 goto out_mcesa;
220 lowcore_ptr[cpu] = lc;
221 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, __pa(lc));
222 return 0;
223
224out_mcesa:
225 nmi_free_mcesa(&lc->mcesad);
226out:
227 stack_free(mcck_stack);
228 stack_free(async_stack);
229 free_pages(nodat_stack, THREAD_SIZE_ORDER);
230 free_pages((unsigned long) lc, LC_ORDER);
231 return -ENOMEM;
232}
233
234static void pcpu_free_lowcore(struct pcpu *pcpu)
235{
236 unsigned long async_stack, nodat_stack, mcck_stack;
237 struct lowcore *lc;
238 int cpu;
239
240 cpu = pcpu - pcpu_devices;
241 lc = lowcore_ptr[cpu];
242 nodat_stack = lc->nodat_stack - STACK_INIT_OFFSET;
243 async_stack = lc->async_stack - STACK_INIT_OFFSET;
244 mcck_stack = lc->mcck_stack - STACK_INIT_OFFSET;
245 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0);
246 lowcore_ptr[cpu] = NULL;
247 abs_lowcore_unmap(cpu);
248 nmi_free_mcesa(&lc->mcesad);
249 stack_free(async_stack);
250 stack_free(mcck_stack);
251 free_pages(nodat_stack, THREAD_SIZE_ORDER);
252 free_pages((unsigned long) lc, LC_ORDER);
253}
254
255static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu)
256{
257 struct lowcore *lc, *abs_lc;
258
259 lc = lowcore_ptr[cpu];
260 cpumask_set_cpu(cpu, &init_mm.context.cpu_attach_mask);
261 cpumask_set_cpu(cpu, mm_cpumask(&init_mm));
262 lc->cpu_nr = cpu;
263 lc->restart_flags = RESTART_FLAG_CTLREGS;
264 lc->spinlock_lockval = arch_spin_lockval(cpu);
265 lc->spinlock_index = 0;
266 lc->percpu_offset = __per_cpu_offset[cpu];
267 lc->kernel_asce = S390_lowcore.kernel_asce;
268 lc->user_asce = s390_invalid_asce;
269 lc->machine_flags = S390_lowcore.machine_flags;
270 lc->user_timer = lc->system_timer =
271 lc->steal_timer = lc->avg_steal_timer = 0;
272 abs_lc = get_abs_lowcore();
273 memcpy(lc->cregs_save_area, abs_lc->cregs_save_area, sizeof(lc->cregs_save_area));
274 put_abs_lowcore(abs_lc);
275 lc->cregs_save_area[1] = lc->kernel_asce;
276 lc->cregs_save_area[7] = lc->user_asce;
277 save_access_regs((unsigned int *) lc->access_regs_save_area);
278 arch_spin_lock_setup(cpu);
279}
280
281static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk)
282{
283 struct lowcore *lc;
284 int cpu;
285
286 cpu = pcpu - pcpu_devices;
287 lc = lowcore_ptr[cpu];
288 lc->kernel_stack = (unsigned long)task_stack_page(tsk) + STACK_INIT_OFFSET;
289 lc->current_task = (unsigned long)tsk;
290 lc->lpp = LPP_MAGIC;
291 lc->current_pid = tsk->pid;
292 lc->user_timer = tsk->thread.user_timer;
293 lc->guest_timer = tsk->thread.guest_timer;
294 lc->system_timer = tsk->thread.system_timer;
295 lc->hardirq_timer = tsk->thread.hardirq_timer;
296 lc->softirq_timer = tsk->thread.softirq_timer;
297 lc->steal_timer = 0;
298}
299
300static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data)
301{
302 struct lowcore *lc;
303 int cpu;
304
305 cpu = pcpu - pcpu_devices;
306 lc = lowcore_ptr[cpu];
307 lc->restart_stack = lc->kernel_stack;
308 lc->restart_fn = (unsigned long) func;
309 lc->restart_data = (unsigned long) data;
310 lc->restart_source = -1U;
311 pcpu_sigp_retry(pcpu, SIGP_RESTART, 0);
312}
313
314typedef void (pcpu_delegate_fn)(void *);
315
316/*
317 * Call function via PSW restart on pcpu and stop the current cpu.
318 */
319static void __pcpu_delegate(pcpu_delegate_fn *func, void *data)
320{
321 func(data); /* should not return */
322}
323
324static void pcpu_delegate(struct pcpu *pcpu,
325 pcpu_delegate_fn *func,
326 void *data, unsigned long stack)
327{
328 struct lowcore *lc, *abs_lc;
329 unsigned int source_cpu;
330
331 lc = lowcore_ptr[pcpu - pcpu_devices];
332 source_cpu = stap();
333
334 if (pcpu->address == source_cpu) {
335 call_on_stack(2, stack, void, __pcpu_delegate,
336 pcpu_delegate_fn *, func, void *, data);
337 }
338 /* Stop target cpu (if func returns this stops the current cpu). */
339 pcpu_sigp_retry(pcpu, SIGP_STOP, 0);
340 pcpu_sigp_retry(pcpu, SIGP_CPU_RESET, 0);
341 /* Restart func on the target cpu and stop the current cpu. */
342 if (lc) {
343 lc->restart_stack = stack;
344 lc->restart_fn = (unsigned long)func;
345 lc->restart_data = (unsigned long)data;
346 lc->restart_source = source_cpu;
347 } else {
348 abs_lc = get_abs_lowcore();
349 abs_lc->restart_stack = stack;
350 abs_lc->restart_fn = (unsigned long)func;
351 abs_lc->restart_data = (unsigned long)data;
352 abs_lc->restart_source = source_cpu;
353 put_abs_lowcore(abs_lc);
354 }
355 asm volatile(
356 "0: sigp 0,%0,%2 # sigp restart to target cpu\n"
357 " brc 2,0b # busy, try again\n"
358 "1: sigp 0,%1,%3 # sigp stop to current cpu\n"
359 " brc 2,1b # busy, try again\n"
360 : : "d" (pcpu->address), "d" (source_cpu),
361 "K" (SIGP_RESTART), "K" (SIGP_STOP)
362 : "0", "1", "cc");
363 for (;;) ;
364}
365
366/*
367 * Enable additional logical cpus for multi-threading.
368 */
369static int pcpu_set_smt(unsigned int mtid)
370{
371 int cc;
372
373 if (smp_cpu_mtid == mtid)
374 return 0;
375 cc = __pcpu_sigp(0, SIGP_SET_MULTI_THREADING, mtid, NULL);
376 if (cc == 0) {
377 smp_cpu_mtid = mtid;
378 smp_cpu_mt_shift = 0;
379 while (smp_cpu_mtid >= (1U << smp_cpu_mt_shift))
380 smp_cpu_mt_shift++;
381 pcpu_devices[0].address = stap();
382 }
383 return cc;
384}
385
386/*
387 * Call function on an online CPU.
388 */
389void smp_call_online_cpu(void (*func)(void *), void *data)
390{
391 struct pcpu *pcpu;
392
393 /* Use the current cpu if it is online. */
394 pcpu = pcpu_find_address(cpu_online_mask, stap());
395 if (!pcpu)
396 /* Use the first online cpu. */
397 pcpu = pcpu_devices + cpumask_first(cpu_online_mask);
398 pcpu_delegate(pcpu, func, data, (unsigned long) restart_stack);
399}
400
401/*
402 * Call function on the ipl CPU.
403 */
404void smp_call_ipl_cpu(void (*func)(void *), void *data)
405{
406 struct lowcore *lc = lowcore_ptr[0];
407
408 if (pcpu_devices[0].address == stap())
409 lc = &S390_lowcore;
410
411 pcpu_delegate(&pcpu_devices[0], func, data,
412 lc->nodat_stack);
413}
414
415int smp_find_processor_id(u16 address)
416{
417 int cpu;
418
419 for_each_present_cpu(cpu)
420 if (pcpu_devices[cpu].address == address)
421 return cpu;
422 return -1;
423}
424
425void schedule_mcck_handler(void)
426{
427 pcpu_ec_call(pcpu_devices + smp_processor_id(), ec_mcck_pending);
428}
429
430bool notrace arch_vcpu_is_preempted(int cpu)
431{
432 if (test_cpu_flag_of(CIF_ENABLED_WAIT, cpu))
433 return false;
434 if (pcpu_running(pcpu_devices + cpu))
435 return false;
436 return true;
437}
438EXPORT_SYMBOL(arch_vcpu_is_preempted);
439
440void notrace smp_yield_cpu(int cpu)
441{
442 if (!MACHINE_HAS_DIAG9C)
443 return;
444 diag_stat_inc_norecursion(DIAG_STAT_X09C);
445 asm volatile("diag %0,0,0x9c"
446 : : "d" (pcpu_devices[cpu].address));
447}
448EXPORT_SYMBOL_GPL(smp_yield_cpu);
449
450/*
451 * Send cpus emergency shutdown signal. This gives the cpus the
452 * opportunity to complete outstanding interrupts.
453 */
454void notrace smp_emergency_stop(void)
455{
456 static arch_spinlock_t lock = __ARCH_SPIN_LOCK_UNLOCKED;
457 static cpumask_t cpumask;
458 u64 end;
459 int cpu;
460
461 arch_spin_lock(&lock);
462 cpumask_copy(&cpumask, cpu_online_mask);
463 cpumask_clear_cpu(smp_processor_id(), &cpumask);
464
465 end = get_tod_clock() + (1000000UL << 12);
466 for_each_cpu(cpu, &cpumask) {
467 struct pcpu *pcpu = pcpu_devices + cpu;
468 set_bit(ec_stop_cpu, &pcpu->ec_mask);
469 while (__pcpu_sigp(pcpu->address, SIGP_EMERGENCY_SIGNAL,
470 0, NULL) == SIGP_CC_BUSY &&
471 get_tod_clock() < end)
472 cpu_relax();
473 }
474 while (get_tod_clock() < end) {
475 for_each_cpu(cpu, &cpumask)
476 if (pcpu_stopped(pcpu_devices + cpu))
477 cpumask_clear_cpu(cpu, &cpumask);
478 if (cpumask_empty(&cpumask))
479 break;
480 cpu_relax();
481 }
482 arch_spin_unlock(&lock);
483}
484NOKPROBE_SYMBOL(smp_emergency_stop);
485
486/*
487 * Stop all cpus but the current one.
488 */
489void smp_send_stop(void)
490{
491 int cpu;
492
493 /* Disable all interrupts/machine checks */
494 __load_psw_mask(PSW_KERNEL_BITS);
495 trace_hardirqs_off();
496
497 debug_set_critical();
498
499 if (oops_in_progress)
500 smp_emergency_stop();
501
502 /* stop all processors */
503 for_each_online_cpu(cpu) {
504 if (cpu == smp_processor_id())
505 continue;
506 pcpu_sigp_retry(pcpu_devices + cpu, SIGP_STOP, 0);
507 while (!pcpu_stopped(pcpu_devices + cpu))
508 cpu_relax();
509 }
510}
511
512/*
513 * This is the main routine where commands issued by other
514 * cpus are handled.
515 */
516static void smp_handle_ext_call(void)
517{
518 unsigned long bits;
519
520 /* handle bit signal external calls */
521 bits = xchg(&pcpu_devices[smp_processor_id()].ec_mask, 0);
522 if (test_bit(ec_stop_cpu, &bits))
523 smp_stop_cpu();
524 if (test_bit(ec_schedule, &bits))
525 scheduler_ipi();
526 if (test_bit(ec_call_function_single, &bits))
527 generic_smp_call_function_single_interrupt();
528 if (test_bit(ec_mcck_pending, &bits))
529 s390_handle_mcck();
530 if (test_bit(ec_irq_work, &bits))
531 irq_work_run();
532}
533
534static void do_ext_call_interrupt(struct ext_code ext_code,
535 unsigned int param32, unsigned long param64)
536{
537 inc_irq_stat(ext_code.code == 0x1202 ? IRQEXT_EXC : IRQEXT_EMS);
538 smp_handle_ext_call();
539}
540
541void arch_send_call_function_ipi_mask(const struct cpumask *mask)
542{
543 int cpu;
544
545 for_each_cpu(cpu, mask)
546 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
547}
548
549void arch_send_call_function_single_ipi(int cpu)
550{
551 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
552}
553
554/*
555 * this function sends a 'reschedule' IPI to another CPU.
556 * it goes straight through and wastes no time serializing
557 * anything. Worst case is that we lose a reschedule ...
558 */
559void arch_smp_send_reschedule(int cpu)
560{
561 pcpu_ec_call(pcpu_devices + cpu, ec_schedule);
562}
563
564#ifdef CONFIG_IRQ_WORK
565void arch_irq_work_raise(void)
566{
567 pcpu_ec_call(pcpu_devices + smp_processor_id(), ec_irq_work);
568}
569#endif
570
571#ifdef CONFIG_CRASH_DUMP
572
573int smp_store_status(int cpu)
574{
575 struct lowcore *lc;
576 struct pcpu *pcpu;
577 unsigned long pa;
578
579 pcpu = pcpu_devices + cpu;
580 lc = lowcore_ptr[cpu];
581 pa = __pa(&lc->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 (!cpu_has_vx() && !MACHINE_HAS_GS)
586 return 0;
587 pa = lc->mcesad & MCESA_ORIGIN_MASK;
588 if (MACHINE_HAS_GS)
589 pa |= lc->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/nvme dump
600 * condition: OLDMEM_BASE == NULL && is_ipl_type_dump() == true
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/NVMe (zfcp/nvme dump with swapped memory)
606 * condition: OLDMEM_BASE != NULL && is_ipl_type_dump() == true
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 bool dump_available(void)
623{
624 return oldmem_data.start || is_ipl_type_dump();
625}
626
627void __init smp_save_dump_ipl_cpu(void)
628{
629 struct save_area *sa;
630 void *regs;
631
632 if (!dump_available())
633 return;
634 sa = save_area_alloc(true);
635 regs = memblock_alloc(512, 8);
636 if (!sa || !regs)
637 panic("could not allocate memory for boot CPU save area\n");
638 copy_oldmem_kernel(regs, __LC_FPREGS_SAVE_AREA, 512);
639 save_area_add_regs(sa, regs);
640 memblock_free(regs, 512);
641 if (cpu_has_vx())
642 save_area_add_vxrs(sa, boot_cpu_vector_save_area);
643}
644
645void __init smp_save_dump_secondary_cpus(void)
646{
647 int addr, boot_cpu_addr, max_cpu_addr;
648 struct save_area *sa;
649 void *page;
650
651 if (!dump_available())
652 return;
653 /* Allocate a page as dumping area for the store status sigps */
654 page = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
655 if (!page)
656 panic("ERROR: Failed to allocate %lx bytes below %lx\n",
657 PAGE_SIZE, 1UL << 31);
658
659 /* Set multi-threading state to the previous system. */
660 pcpu_set_smt(sclp.mtid_prev);
661 boot_cpu_addr = stap();
662 max_cpu_addr = SCLP_MAX_CORES << sclp.mtid_prev;
663 for (addr = 0; addr <= max_cpu_addr; addr++) {
664 if (addr == boot_cpu_addr)
665 continue;
666 if (__pcpu_sigp_relax(addr, SIGP_SENSE, 0) ==
667 SIGP_CC_NOT_OPERATIONAL)
668 continue;
669 sa = save_area_alloc(false);
670 if (!sa)
671 panic("could not allocate memory for save area\n");
672 __pcpu_sigp_relax(addr, SIGP_STORE_STATUS_AT_ADDRESS, __pa(page));
673 save_area_add_regs(sa, page);
674 if (cpu_has_vx()) {
675 __pcpu_sigp_relax(addr, SIGP_STORE_ADDITIONAL_STATUS, __pa(page));
676 save_area_add_vxrs(sa, page);
677 }
678 }
679 memblock_free(page, PAGE_SIZE);
680 diag_amode31_ops.diag308_reset();
681 pcpu_set_smt(0);
682}
683#endif /* CONFIG_CRASH_DUMP */
684
685void smp_cpu_set_polarization(int cpu, int val)
686{
687 pcpu_devices[cpu].polarization = val;
688}
689
690int smp_cpu_get_polarization(int cpu)
691{
692 return pcpu_devices[cpu].polarization;
693}
694
695int smp_cpu_get_cpu_address(int cpu)
696{
697 return pcpu_devices[cpu].address;
698}
699
700static void __ref smp_get_core_info(struct sclp_core_info *info, int early)
701{
702 static int use_sigp_detection;
703 int address;
704
705 if (use_sigp_detection || sclp_get_core_info(info, early)) {
706 use_sigp_detection = 1;
707 for (address = 0;
708 address < (SCLP_MAX_CORES << smp_cpu_mt_shift);
709 address += (1U << smp_cpu_mt_shift)) {
710 if (__pcpu_sigp_relax(address, SIGP_SENSE, 0) ==
711 SIGP_CC_NOT_OPERATIONAL)
712 continue;
713 info->core[info->configured].core_id =
714 address >> smp_cpu_mt_shift;
715 info->configured++;
716 }
717 info->combined = info->configured;
718 }
719}
720
721static int smp_add_present_cpu(int cpu);
722
723static int smp_add_core(struct sclp_core_entry *core, cpumask_t *avail,
724 bool configured, bool early)
725{
726 struct pcpu *pcpu;
727 int cpu, nr, i;
728 u16 address;
729
730 nr = 0;
731 if (sclp.has_core_type && core->type != boot_core_type)
732 return nr;
733 cpu = cpumask_first(avail);
734 address = core->core_id << smp_cpu_mt_shift;
735 for (i = 0; (i <= smp_cpu_mtid) && (cpu < nr_cpu_ids); i++) {
736 if (pcpu_find_address(cpu_present_mask, address + i))
737 continue;
738 pcpu = pcpu_devices + cpu;
739 pcpu->address = address + i;
740 if (configured)
741 pcpu->state = CPU_STATE_CONFIGURED;
742 else
743 pcpu->state = CPU_STATE_STANDBY;
744 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
745 set_cpu_present(cpu, true);
746 if (!early && smp_add_present_cpu(cpu) != 0)
747 set_cpu_present(cpu, false);
748 else
749 nr++;
750 cpumask_clear_cpu(cpu, avail);
751 cpu = cpumask_next(cpu, avail);
752 }
753 return nr;
754}
755
756static int __smp_rescan_cpus(struct sclp_core_info *info, bool early)
757{
758 struct sclp_core_entry *core;
759 static cpumask_t avail;
760 bool configured;
761 u16 core_id;
762 int nr, i;
763
764 cpus_read_lock();
765 mutex_lock(&smp_cpu_state_mutex);
766 nr = 0;
767 cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask);
768 /*
769 * Add IPL core first (which got logical CPU number 0) to make sure
770 * that all SMT threads get subsequent logical CPU numbers.
771 */
772 if (early) {
773 core_id = pcpu_devices[0].address >> smp_cpu_mt_shift;
774 for (i = 0; i < info->configured; i++) {
775 core = &info->core[i];
776 if (core->core_id == core_id) {
777 nr += smp_add_core(core, &avail, true, early);
778 break;
779 }
780 }
781 }
782 for (i = 0; i < info->combined; i++) {
783 configured = i < info->configured;
784 nr += smp_add_core(&info->core[i], &avail, configured, early);
785 }
786 mutex_unlock(&smp_cpu_state_mutex);
787 cpus_read_unlock();
788 return nr;
789}
790
791void __init smp_detect_cpus(void)
792{
793 unsigned int cpu, mtid, c_cpus, s_cpus;
794 struct sclp_core_info *info;
795 u16 address;
796
797 /* Get CPU information */
798 info = memblock_alloc(sizeof(*info), 8);
799 if (!info)
800 panic("%s: Failed to allocate %zu bytes align=0x%x\n",
801 __func__, sizeof(*info), 8);
802 smp_get_core_info(info, 1);
803 /* Find boot CPU type */
804 if (sclp.has_core_type) {
805 address = stap();
806 for (cpu = 0; cpu < info->combined; cpu++)
807 if (info->core[cpu].core_id == address) {
808 /* The boot cpu dictates the cpu type. */
809 boot_core_type = info->core[cpu].type;
810 break;
811 }
812 if (cpu >= info->combined)
813 panic("Could not find boot CPU type");
814 }
815
816 /* Set multi-threading state for the current system */
817 mtid = boot_core_type ? sclp.mtid : sclp.mtid_cp;
818 mtid = (mtid < smp_max_threads) ? mtid : smp_max_threads - 1;
819 pcpu_set_smt(mtid);
820
821 /* Print number of CPUs */
822 c_cpus = s_cpus = 0;
823 for (cpu = 0; cpu < info->combined; cpu++) {
824 if (sclp.has_core_type &&
825 info->core[cpu].type != boot_core_type)
826 continue;
827 if (cpu < info->configured)
828 c_cpus += smp_cpu_mtid + 1;
829 else
830 s_cpus += smp_cpu_mtid + 1;
831 }
832 pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
833
834 /* Add CPUs present at boot */
835 __smp_rescan_cpus(info, true);
836 memblock_free(info, sizeof(*info));
837}
838
839/*
840 * Activate a secondary processor.
841 */
842static void smp_start_secondary(void *cpuvoid)
843{
844 int cpu = raw_smp_processor_id();
845
846 S390_lowcore.last_update_clock = get_tod_clock();
847 S390_lowcore.restart_stack = (unsigned long)restart_stack;
848 S390_lowcore.restart_fn = (unsigned long)do_restart;
849 S390_lowcore.restart_data = 0;
850 S390_lowcore.restart_source = -1U;
851 S390_lowcore.restart_flags = 0;
852 restore_access_regs(S390_lowcore.access_regs_save_area);
853 cpu_init();
854 rcutree_report_cpu_starting(cpu);
855 init_cpu_timer();
856 vtime_init();
857 vdso_getcpu_init();
858 pfault_init();
859 cpumask_set_cpu(cpu, &cpu_setup_mask);
860 update_cpu_masks();
861 notify_cpu_starting(cpu);
862 if (topology_cpu_dedicated(cpu))
863 set_cpu_flag(CIF_DEDICATED_CPU);
864 else
865 clear_cpu_flag(CIF_DEDICATED_CPU);
866 set_cpu_online(cpu, true);
867 inc_irq_stat(CPU_RST);
868 local_irq_enable();
869 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
870}
871
872/* Upping and downing of CPUs */
873int __cpu_up(unsigned int cpu, struct task_struct *tidle)
874{
875 struct pcpu *pcpu = pcpu_devices + cpu;
876 int rc;
877
878 if (pcpu->state != CPU_STATE_CONFIGURED)
879 return -EIO;
880 if (pcpu_sigp_retry(pcpu, SIGP_INITIAL_CPU_RESET, 0) !=
881 SIGP_CC_ORDER_CODE_ACCEPTED)
882 return -EIO;
883
884 rc = pcpu_alloc_lowcore(pcpu, cpu);
885 if (rc)
886 return rc;
887 /*
888 * Make sure global control register contents do not change
889 * until new CPU has initialized control registers.
890 */
891 system_ctlreg_lock();
892 pcpu_prepare_secondary(pcpu, cpu);
893 pcpu_attach_task(pcpu, tidle);
894 pcpu_start_fn(pcpu, smp_start_secondary, NULL);
895 /* Wait until cpu puts itself in the online & active maps */
896 while (!cpu_online(cpu))
897 cpu_relax();
898 system_ctlreg_unlock();
899 return 0;
900}
901
902static unsigned int setup_possible_cpus __initdata;
903
904static int __init _setup_possible_cpus(char *s)
905{
906 get_option(&s, &setup_possible_cpus);
907 return 0;
908}
909early_param("possible_cpus", _setup_possible_cpus);
910
911int __cpu_disable(void)
912{
913 struct ctlreg cregs[16];
914 int cpu;
915
916 /* Handle possible pending IPIs */
917 smp_handle_ext_call();
918 cpu = smp_processor_id();
919 set_cpu_online(cpu, false);
920 cpumask_clear_cpu(cpu, &cpu_setup_mask);
921 update_cpu_masks();
922 /* Disable pseudo page faults on this cpu. */
923 pfault_fini();
924 /* Disable interrupt sources via control register. */
925 __local_ctl_store(0, 15, cregs);
926 cregs[0].val &= ~0x0000ee70UL; /* disable all external interrupts */
927 cregs[6].val &= ~0xff000000UL; /* disable all I/O interrupts */
928 cregs[14].val &= ~0x1f000000UL; /* disable most machine checks */
929 __local_ctl_load(0, 15, cregs);
930 clear_cpu_flag(CIF_NOHZ_DELAY);
931 return 0;
932}
933
934void __cpu_die(unsigned int cpu)
935{
936 struct pcpu *pcpu;
937
938 /* Wait until target cpu is down */
939 pcpu = pcpu_devices + cpu;
940 while (!pcpu_stopped(pcpu))
941 cpu_relax();
942 pcpu_free_lowcore(pcpu);
943 cpumask_clear_cpu(cpu, mm_cpumask(&init_mm));
944 cpumask_clear_cpu(cpu, &init_mm.context.cpu_attach_mask);
945}
946
947void __noreturn cpu_die(void)
948{
949 idle_task_exit();
950 pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0);
951 for (;;) ;
952}
953
954void __init smp_fill_possible_mask(void)
955{
956 unsigned int possible, sclp_max, cpu;
957
958 sclp_max = max(sclp.mtid, sclp.mtid_cp) + 1;
959 sclp_max = min(smp_max_threads, sclp_max);
960 sclp_max = (sclp.max_cores * sclp_max) ?: nr_cpu_ids;
961 possible = setup_possible_cpus ?: nr_cpu_ids;
962 possible = min(possible, sclp_max);
963 for (cpu = 0; cpu < possible && cpu < nr_cpu_ids; cpu++)
964 set_cpu_possible(cpu, true);
965}
966
967void __init smp_prepare_cpus(unsigned int max_cpus)
968{
969 if (register_external_irq(EXT_IRQ_EMERGENCY_SIG, do_ext_call_interrupt))
970 panic("Couldn't request external interrupt 0x1201");
971 system_ctl_set_bit(0, 14);
972 if (register_external_irq(EXT_IRQ_EXTERNAL_CALL, do_ext_call_interrupt))
973 panic("Couldn't request external interrupt 0x1202");
974 system_ctl_set_bit(0, 13);
975}
976
977void __init smp_prepare_boot_cpu(void)
978{
979 struct pcpu *pcpu = pcpu_devices;
980
981 WARN_ON(!cpu_present(0) || !cpu_online(0));
982 pcpu->state = CPU_STATE_CONFIGURED;
983 S390_lowcore.percpu_offset = __per_cpu_offset[0];
984 smp_cpu_set_polarization(0, POLARIZATION_UNKNOWN);
985}
986
987void __init smp_setup_processor_id(void)
988{
989 pcpu_devices[0].address = stap();
990 S390_lowcore.cpu_nr = 0;
991 S390_lowcore.spinlock_lockval = arch_spin_lockval(0);
992 S390_lowcore.spinlock_index = 0;
993}
994
995/*
996 * the frequency of the profiling timer can be changed
997 * by writing a multiplier value into /proc/profile.
998 *
999 * usually you want to run this on all CPUs ;)
1000 */
1001int setup_profiling_timer(unsigned int multiplier)
1002{
1003 return 0;
1004}
1005
1006static ssize_t cpu_configure_show(struct device *dev,
1007 struct device_attribute *attr, char *buf)
1008{
1009 ssize_t count;
1010
1011 mutex_lock(&smp_cpu_state_mutex);
1012 count = sprintf(buf, "%d\n", pcpu_devices[dev->id].state);
1013 mutex_unlock(&smp_cpu_state_mutex);
1014 return count;
1015}
1016
1017static ssize_t cpu_configure_store(struct device *dev,
1018 struct device_attribute *attr,
1019 const char *buf, size_t count)
1020{
1021 struct pcpu *pcpu;
1022 int cpu, val, rc, i;
1023 char delim;
1024
1025 if (sscanf(buf, "%d %c", &val, &delim) != 1)
1026 return -EINVAL;
1027 if (val != 0 && val != 1)
1028 return -EINVAL;
1029 cpus_read_lock();
1030 mutex_lock(&smp_cpu_state_mutex);
1031 rc = -EBUSY;
1032 /* disallow configuration changes of online cpus */
1033 cpu = dev->id;
1034 cpu = smp_get_base_cpu(cpu);
1035 for (i = 0; i <= smp_cpu_mtid; i++)
1036 if (cpu_online(cpu + i))
1037 goto out;
1038 pcpu = pcpu_devices + cpu;
1039 rc = 0;
1040 switch (val) {
1041 case 0:
1042 if (pcpu->state != CPU_STATE_CONFIGURED)
1043 break;
1044 rc = sclp_core_deconfigure(pcpu->address >> smp_cpu_mt_shift);
1045 if (rc)
1046 break;
1047 for (i = 0; i <= smp_cpu_mtid; i++) {
1048 if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i))
1049 continue;
1050 pcpu[i].state = CPU_STATE_STANDBY;
1051 smp_cpu_set_polarization(cpu + i,
1052 POLARIZATION_UNKNOWN);
1053 }
1054 topology_expect_change();
1055 break;
1056 case 1:
1057 if (pcpu->state != CPU_STATE_STANDBY)
1058 break;
1059 rc = sclp_core_configure(pcpu->address >> smp_cpu_mt_shift);
1060 if (rc)
1061 break;
1062 for (i = 0; i <= smp_cpu_mtid; i++) {
1063 if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i))
1064 continue;
1065 pcpu[i].state = CPU_STATE_CONFIGURED;
1066 smp_cpu_set_polarization(cpu + i,
1067 POLARIZATION_UNKNOWN);
1068 }
1069 topology_expect_change();
1070 break;
1071 default:
1072 break;
1073 }
1074out:
1075 mutex_unlock(&smp_cpu_state_mutex);
1076 cpus_read_unlock();
1077 return rc ? rc : count;
1078}
1079static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
1080
1081static ssize_t show_cpu_address(struct device *dev,
1082 struct device_attribute *attr, char *buf)
1083{
1084 return sprintf(buf, "%d\n", pcpu_devices[dev->id].address);
1085}
1086static DEVICE_ATTR(address, 0444, show_cpu_address, NULL);
1087
1088static struct attribute *cpu_common_attrs[] = {
1089 &dev_attr_configure.attr,
1090 &dev_attr_address.attr,
1091 NULL,
1092};
1093
1094static struct attribute_group cpu_common_attr_group = {
1095 .attrs = cpu_common_attrs,
1096};
1097
1098static struct attribute *cpu_online_attrs[] = {
1099 &dev_attr_idle_count.attr,
1100 &dev_attr_idle_time_us.attr,
1101 NULL,
1102};
1103
1104static struct attribute_group cpu_online_attr_group = {
1105 .attrs = cpu_online_attrs,
1106};
1107
1108static int smp_cpu_online(unsigned int cpu)
1109{
1110 struct device *s = &per_cpu(cpu_device, cpu)->dev;
1111
1112 return sysfs_create_group(&s->kobj, &cpu_online_attr_group);
1113}
1114
1115static int smp_cpu_pre_down(unsigned int cpu)
1116{
1117 struct device *s = &per_cpu(cpu_device, cpu)->dev;
1118
1119 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
1120 return 0;
1121}
1122
1123static int smp_add_present_cpu(int cpu)
1124{
1125 struct device *s;
1126 struct cpu *c;
1127 int rc;
1128
1129 c = kzalloc(sizeof(*c), GFP_KERNEL);
1130 if (!c)
1131 return -ENOMEM;
1132 per_cpu(cpu_device, cpu) = c;
1133 s = &c->dev;
1134 c->hotpluggable = !!cpu;
1135 rc = register_cpu(c, cpu);
1136 if (rc)
1137 goto out;
1138 rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
1139 if (rc)
1140 goto out_cpu;
1141 rc = topology_cpu_init(c);
1142 if (rc)
1143 goto out_topology;
1144 return 0;
1145
1146out_topology:
1147 sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
1148out_cpu:
1149 unregister_cpu(c);
1150out:
1151 return rc;
1152}
1153
1154int __ref smp_rescan_cpus(void)
1155{
1156 struct sclp_core_info *info;
1157 int nr;
1158
1159 info = kzalloc(sizeof(*info), GFP_KERNEL);
1160 if (!info)
1161 return -ENOMEM;
1162 smp_get_core_info(info, 0);
1163 nr = __smp_rescan_cpus(info, false);
1164 kfree(info);
1165 if (nr)
1166 topology_schedule_update();
1167 return 0;
1168}
1169
1170static ssize_t __ref rescan_store(struct device *dev,
1171 struct device_attribute *attr,
1172 const char *buf,
1173 size_t count)
1174{
1175 int rc;
1176
1177 rc = lock_device_hotplug_sysfs();
1178 if (rc)
1179 return rc;
1180 rc = smp_rescan_cpus();
1181 unlock_device_hotplug();
1182 return rc ? rc : count;
1183}
1184static DEVICE_ATTR_WO(rescan);
1185
1186static int __init s390_smp_init(void)
1187{
1188 struct device *dev_root;
1189 int cpu, rc = 0;
1190
1191 dev_root = bus_get_dev_root(&cpu_subsys);
1192 if (dev_root) {
1193 rc = device_create_file(dev_root, &dev_attr_rescan);
1194 put_device(dev_root);
1195 if (rc)
1196 return rc;
1197 }
1198
1199 for_each_present_cpu(cpu) {
1200 rc = smp_add_present_cpu(cpu);
1201 if (rc)
1202 goto out;
1203 }
1204
1205 rc = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "s390/smp:online",
1206 smp_cpu_online, smp_cpu_pre_down);
1207 rc = rc <= 0 ? rc : 0;
1208out:
1209 return rc;
1210}
1211subsys_initcall(s390_smp_init);
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/vtimer.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 <asm/sigp.h>
48#include "entry.h"
49
50enum {
51 ec_schedule = 0,
52 ec_call_function_single,
53 ec_stop_cpu,
54};
55
56enum {
57 CPU_STATE_STANDBY,
58 CPU_STATE_CONFIGURED,
59};
60
61struct pcpu {
62 struct cpu *cpu;
63 struct _lowcore *lowcore; /* lowcore page(s) for the cpu */
64 unsigned long async_stack; /* async stack for the cpu */
65 unsigned long panic_stack; /* panic stack for the cpu */
66 unsigned long ec_mask; /* bit mask for ec_xxx functions */
67 int state; /* physical cpu state */
68 int polarization; /* physical polarization */
69 u16 address; /* physical cpu address */
70};
71
72static u8 boot_cpu_type;
73static u16 boot_cpu_address;
74static struct pcpu pcpu_devices[NR_CPUS];
75
76/*
77 * The smp_cpu_state_mutex must be held when changing the state or polarization
78 * member of a pcpu data structure within the pcpu_devices arreay.
79 */
80DEFINE_MUTEX(smp_cpu_state_mutex);
81
82/*
83 * Signal processor helper functions.
84 */
85static inline int __pcpu_sigp_relax(u16 addr, u8 order, u32 parm, u32 *status)
86{
87 int cc;
88
89 while (1) {
90 cc = __pcpu_sigp(addr, order, parm, NULL);
91 if (cc != SIGP_CC_BUSY)
92 return cc;
93 cpu_relax();
94 }
95}
96
97static int pcpu_sigp_retry(struct pcpu *pcpu, u8 order, u32 parm)
98{
99 int cc, retry;
100
101 for (retry = 0; ; retry++) {
102 cc = __pcpu_sigp(pcpu->address, order, parm, NULL);
103 if (cc != SIGP_CC_BUSY)
104 break;
105 if (retry >= 3)
106 udelay(10);
107 }
108 return cc;
109}
110
111static inline int pcpu_stopped(struct pcpu *pcpu)
112{
113 u32 uninitialized_var(status);
114
115 if (__pcpu_sigp(pcpu->address, SIGP_SENSE,
116 0, &status) != SIGP_CC_STATUS_STORED)
117 return 0;
118 return !!(status & (SIGP_STATUS_CHECK_STOP|SIGP_STATUS_STOPPED));
119}
120
121static inline int pcpu_running(struct pcpu *pcpu)
122{
123 if (__pcpu_sigp(pcpu->address, SIGP_SENSE_RUNNING,
124 0, NULL) != SIGP_CC_STATUS_STORED)
125 return 1;
126 /* Status stored condition code is equivalent to cpu not running. */
127 return 0;
128}
129
130/*
131 * Find struct pcpu by cpu address.
132 */
133static struct pcpu *pcpu_find_address(const struct cpumask *mask, int address)
134{
135 int cpu;
136
137 for_each_cpu(cpu, mask)
138 if (pcpu_devices[cpu].address == address)
139 return pcpu_devices + cpu;
140 return NULL;
141}
142
143static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit)
144{
145 int order;
146
147 if (test_and_set_bit(ec_bit, &pcpu->ec_mask))
148 return;
149 order = pcpu_running(pcpu) ? SIGP_EXTERNAL_CALL : SIGP_EMERGENCY_SIGNAL;
150 pcpu_sigp_retry(pcpu, order, 0);
151}
152
153static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
154{
155 struct _lowcore *lc;
156
157 if (pcpu != &pcpu_devices[0]) {
158 pcpu->lowcore = (struct _lowcore *)
159 __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
160 pcpu->async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
161 pcpu->panic_stack = __get_free_page(GFP_KERNEL);
162 if (!pcpu->lowcore || !pcpu->panic_stack || !pcpu->async_stack)
163 goto out;
164 }
165 lc = pcpu->lowcore;
166 memcpy(lc, &S390_lowcore, 512);
167 memset((char *) lc + 512, 0, sizeof(*lc) - 512);
168 lc->async_stack = pcpu->async_stack + ASYNC_SIZE
169 - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
170 lc->panic_stack = pcpu->panic_stack + PAGE_SIZE
171 - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
172 lc->cpu_nr = cpu;
173#ifndef CONFIG_64BIT
174 if (MACHINE_HAS_IEEE) {
175 lc->extended_save_area_addr = get_zeroed_page(GFP_KERNEL);
176 if (!lc->extended_save_area_addr)
177 goto out;
178 }
179#else
180 if (vdso_alloc_per_cpu(lc))
181 goto out;
182#endif
183 lowcore_ptr[cpu] = lc;
184 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, (u32)(unsigned long) lc);
185 return 0;
186out:
187 if (pcpu != &pcpu_devices[0]) {
188 free_page(pcpu->panic_stack);
189 free_pages(pcpu->async_stack, ASYNC_ORDER);
190 free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
191 }
192 return -ENOMEM;
193}
194
195#ifdef CONFIG_HOTPLUG_CPU
196
197static void pcpu_free_lowcore(struct pcpu *pcpu)
198{
199 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0);
200 lowcore_ptr[pcpu - pcpu_devices] = NULL;
201#ifndef CONFIG_64BIT
202 if (MACHINE_HAS_IEEE) {
203 struct _lowcore *lc = pcpu->lowcore;
204
205 free_page((unsigned long) lc->extended_save_area_addr);
206 lc->extended_save_area_addr = 0;
207 }
208#else
209 vdso_free_per_cpu(pcpu->lowcore);
210#endif
211 if (pcpu != &pcpu_devices[0]) {
212 free_page(pcpu->panic_stack);
213 free_pages(pcpu->async_stack, ASYNC_ORDER);
214 free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
215 }
216}
217
218#endif /* CONFIG_HOTPLUG_CPU */
219
220static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu)
221{
222 struct _lowcore *lc = pcpu->lowcore;
223
224 if (MACHINE_HAS_TLB_LC)
225 cpumask_set_cpu(cpu, &init_mm.context.cpu_attach_mask);
226 cpumask_set_cpu(cpu, mm_cpumask(&init_mm));
227 atomic_inc(&init_mm.context.attach_count);
228 lc->cpu_nr = cpu;
229 lc->percpu_offset = __per_cpu_offset[cpu];
230 lc->kernel_asce = S390_lowcore.kernel_asce;
231 lc->machine_flags = S390_lowcore.machine_flags;
232 lc->ftrace_func = S390_lowcore.ftrace_func;
233 lc->user_timer = lc->system_timer = lc->steal_timer = 0;
234 __ctl_store(lc->cregs_save_area, 0, 15);
235 save_access_regs((unsigned int *) lc->access_regs_save_area);
236 memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,
237 MAX_FACILITY_BIT/8);
238}
239
240static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk)
241{
242 struct _lowcore *lc = pcpu->lowcore;
243 struct thread_info *ti = task_thread_info(tsk);
244
245 lc->kernel_stack = (unsigned long) task_stack_page(tsk)
246 + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
247 lc->thread_info = (unsigned long) task_thread_info(tsk);
248 lc->current_task = (unsigned long) tsk;
249 lc->user_timer = ti->user_timer;
250 lc->system_timer = ti->system_timer;
251 lc->steal_timer = 0;
252}
253
254static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data)
255{
256 struct _lowcore *lc = pcpu->lowcore;
257
258 lc->restart_stack = lc->kernel_stack;
259 lc->restart_fn = (unsigned long) func;
260 lc->restart_data = (unsigned long) data;
261 lc->restart_source = -1UL;
262 pcpu_sigp_retry(pcpu, SIGP_RESTART, 0);
263}
264
265/*
266 * Call function via PSW restart on pcpu and stop the current cpu.
267 */
268static void pcpu_delegate(struct pcpu *pcpu, void (*func)(void *),
269 void *data, unsigned long stack)
270{
271 struct _lowcore *lc = lowcore_ptr[pcpu - pcpu_devices];
272 unsigned long source_cpu = stap();
273
274 __load_psw_mask(PSW_KERNEL_BITS);
275 if (pcpu->address == source_cpu)
276 func(data); /* should not return */
277 /* Stop target cpu (if func returns this stops the current cpu). */
278 pcpu_sigp_retry(pcpu, SIGP_STOP, 0);
279 /* Restart func on the target cpu and stop the current cpu. */
280 mem_assign_absolute(lc->restart_stack, stack);
281 mem_assign_absolute(lc->restart_fn, (unsigned long) func);
282 mem_assign_absolute(lc->restart_data, (unsigned long) data);
283 mem_assign_absolute(lc->restart_source, source_cpu);
284 asm volatile(
285 "0: sigp 0,%0,%2 # sigp restart to target cpu\n"
286 " brc 2,0b # busy, try again\n"
287 "1: sigp 0,%1,%3 # sigp stop to current cpu\n"
288 " brc 2,1b # busy, try again\n"
289 : : "d" (pcpu->address), "d" (source_cpu),
290 "K" (SIGP_RESTART), "K" (SIGP_STOP)
291 : "0", "1", "cc");
292 for (;;) ;
293}
294
295/*
296 * Call function on an online CPU.
297 */
298void smp_call_online_cpu(void (*func)(void *), void *data)
299{
300 struct pcpu *pcpu;
301
302 /* Use the current cpu if it is online. */
303 pcpu = pcpu_find_address(cpu_online_mask, stap());
304 if (!pcpu)
305 /* Use the first online cpu. */
306 pcpu = pcpu_devices + cpumask_first(cpu_online_mask);
307 pcpu_delegate(pcpu, func, data, (unsigned long) restart_stack);
308}
309
310/*
311 * Call function on the ipl CPU.
312 */
313void smp_call_ipl_cpu(void (*func)(void *), void *data)
314{
315 pcpu_delegate(&pcpu_devices[0], func, data,
316 pcpu_devices->panic_stack + PAGE_SIZE);
317}
318
319int smp_find_processor_id(u16 address)
320{
321 int cpu;
322
323 for_each_present_cpu(cpu)
324 if (pcpu_devices[cpu].address == address)
325 return cpu;
326 return -1;
327}
328
329int smp_vcpu_scheduled(int cpu)
330{
331 return pcpu_running(pcpu_devices + cpu);
332}
333
334void smp_yield(void)
335{
336 if (MACHINE_HAS_DIAG44)
337 asm volatile("diag 0,0,0x44");
338}
339
340void smp_yield_cpu(int cpu)
341{
342 if (MACHINE_HAS_DIAG9C)
343 asm volatile("diag %0,0,0x9c"
344 : : "d" (pcpu_devices[cpu].address));
345 else if (MACHINE_HAS_DIAG44)
346 asm volatile("diag 0,0,0x44");
347}
348
349/*
350 * Send cpus emergency shutdown signal. This gives the cpus the
351 * opportunity to complete outstanding interrupts.
352 */
353static void smp_emergency_stop(cpumask_t *cpumask)
354{
355 u64 end;
356 int cpu;
357
358 end = get_tod_clock() + (1000000UL << 12);
359 for_each_cpu(cpu, cpumask) {
360 struct pcpu *pcpu = pcpu_devices + cpu;
361 set_bit(ec_stop_cpu, &pcpu->ec_mask);
362 while (__pcpu_sigp(pcpu->address, SIGP_EMERGENCY_SIGNAL,
363 0, NULL) == SIGP_CC_BUSY &&
364 get_tod_clock() < end)
365 cpu_relax();
366 }
367 while (get_tod_clock() < end) {
368 for_each_cpu(cpu, cpumask)
369 if (pcpu_stopped(pcpu_devices + cpu))
370 cpumask_clear_cpu(cpu, cpumask);
371 if (cpumask_empty(cpumask))
372 break;
373 cpu_relax();
374 }
375}
376
377/*
378 * Stop all cpus but the current one.
379 */
380void smp_send_stop(void)
381{
382 cpumask_t cpumask;
383 int cpu;
384
385 /* Disable all interrupts/machine checks */
386 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
387 trace_hardirqs_off();
388
389 debug_set_critical();
390 cpumask_copy(&cpumask, cpu_online_mask);
391 cpumask_clear_cpu(smp_processor_id(), &cpumask);
392
393 if (oops_in_progress)
394 smp_emergency_stop(&cpumask);
395
396 /* stop all processors */
397 for_each_cpu(cpu, &cpumask) {
398 struct pcpu *pcpu = pcpu_devices + cpu;
399 pcpu_sigp_retry(pcpu, SIGP_STOP, 0);
400 while (!pcpu_stopped(pcpu))
401 cpu_relax();
402 }
403}
404
405/*
406 * Stop the current cpu.
407 */
408void smp_stop_cpu(void)
409{
410 pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0);
411 for (;;) ;
412}
413
414/*
415 * This is the main routine where commands issued by other
416 * cpus are handled.
417 */
418static void smp_handle_ext_call(void)
419{
420 unsigned long bits;
421
422 /* handle bit signal external calls */
423 bits = xchg(&pcpu_devices[smp_processor_id()].ec_mask, 0);
424 if (test_bit(ec_stop_cpu, &bits))
425 smp_stop_cpu();
426 if (test_bit(ec_schedule, &bits))
427 scheduler_ipi();
428 if (test_bit(ec_call_function_single, &bits))
429 generic_smp_call_function_single_interrupt();
430}
431
432static void do_ext_call_interrupt(struct ext_code ext_code,
433 unsigned int param32, unsigned long param64)
434{
435 inc_irq_stat(ext_code.code == 0x1202 ? IRQEXT_EXC : IRQEXT_EMS);
436 smp_handle_ext_call();
437}
438
439void arch_send_call_function_ipi_mask(const struct cpumask *mask)
440{
441 int cpu;
442
443 for_each_cpu(cpu, mask)
444 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
445}
446
447void arch_send_call_function_single_ipi(int cpu)
448{
449 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
450}
451
452#ifndef CONFIG_64BIT
453/*
454 * this function sends a 'purge tlb' signal to another CPU.
455 */
456static void smp_ptlb_callback(void *info)
457{
458 __tlb_flush_local();
459}
460
461void smp_ptlb_all(void)
462{
463 on_each_cpu(smp_ptlb_callback, NULL, 1);
464}
465EXPORT_SYMBOL(smp_ptlb_all);
466#endif /* ! CONFIG_64BIT */
467
468/*
469 * this function sends a 'reschedule' IPI to another CPU.
470 * it goes straight through and wastes no time serializing
471 * anything. Worst case is that we lose a reschedule ...
472 */
473void smp_send_reschedule(int cpu)
474{
475 pcpu_ec_call(pcpu_devices + cpu, ec_schedule);
476}
477
478/*
479 * parameter area for the set/clear control bit callbacks
480 */
481struct ec_creg_mask_parms {
482 unsigned long orval;
483 unsigned long andval;
484 int cr;
485};
486
487/*
488 * callback for setting/clearing control bits
489 */
490static void smp_ctl_bit_callback(void *info)
491{
492 struct ec_creg_mask_parms *pp = info;
493 unsigned long cregs[16];
494
495 __ctl_store(cregs, 0, 15);
496 cregs[pp->cr] = (cregs[pp->cr] & pp->andval) | pp->orval;
497 __ctl_load(cregs, 0, 15);
498}
499
500/*
501 * Set a bit in a control register of all cpus
502 */
503void smp_ctl_set_bit(int cr, int bit)
504{
505 struct ec_creg_mask_parms parms = { 1UL << bit, -1UL, cr };
506
507 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
508}
509EXPORT_SYMBOL(smp_ctl_set_bit);
510
511/*
512 * Clear a bit in a control register of all cpus
513 */
514void smp_ctl_clear_bit(int cr, int bit)
515{
516 struct ec_creg_mask_parms parms = { 0, ~(1UL << bit), cr };
517
518 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
519}
520EXPORT_SYMBOL(smp_ctl_clear_bit);
521
522#if defined(CONFIG_ZFCPDUMP) || defined(CONFIG_CRASH_DUMP)
523
524static void __init smp_get_save_area(int cpu, u16 address)
525{
526 void *lc = pcpu_devices[0].lowcore;
527 struct save_area *save_area;
528
529 if (is_kdump_kernel())
530 return;
531 if (!OLDMEM_BASE && (address == boot_cpu_address ||
532 ipl_info.type != IPL_TYPE_FCP_DUMP))
533 return;
534 save_area = dump_save_area_create(cpu);
535 if (!save_area)
536 panic("could not allocate memory for save area\n");
537#ifdef CONFIG_CRASH_DUMP
538 if (address == boot_cpu_address) {
539 /* Copy the registers of the boot cpu. */
540 copy_oldmem_page(1, (void *) save_area, sizeof(*save_area),
541 SAVE_AREA_BASE - PAGE_SIZE, 0);
542 return;
543 }
544#endif
545 /* Get the registers of a non-boot cpu. */
546 __pcpu_sigp_relax(address, SIGP_STOP_AND_STORE_STATUS, 0, NULL);
547 memcpy_real(save_area, lc + SAVE_AREA_BASE, sizeof(*save_area));
548}
549
550int smp_store_status(int cpu)
551{
552 struct pcpu *pcpu;
553
554 pcpu = pcpu_devices + cpu;
555 if (__pcpu_sigp_relax(pcpu->address, SIGP_STOP_AND_STORE_STATUS,
556 0, NULL) != SIGP_CC_ORDER_CODE_ACCEPTED)
557 return -EIO;
558 return 0;
559}
560
561#else /* CONFIG_ZFCPDUMP || CONFIG_CRASH_DUMP */
562
563static inline void smp_get_save_area(int cpu, u16 address) { }
564
565#endif /* CONFIG_ZFCPDUMP || CONFIG_CRASH_DUMP */
566
567void smp_cpu_set_polarization(int cpu, int val)
568{
569 pcpu_devices[cpu].polarization = val;
570}
571
572int smp_cpu_get_polarization(int cpu)
573{
574 return pcpu_devices[cpu].polarization;
575}
576
577static struct sclp_cpu_info *smp_get_cpu_info(void)
578{
579 static int use_sigp_detection;
580 struct sclp_cpu_info *info;
581 int address;
582
583 info = kzalloc(sizeof(*info), GFP_KERNEL);
584 if (info && (use_sigp_detection || sclp_get_cpu_info(info))) {
585 use_sigp_detection = 1;
586 for (address = 0; address <= MAX_CPU_ADDRESS; address++) {
587 if (__pcpu_sigp_relax(address, SIGP_SENSE, 0, NULL) ==
588 SIGP_CC_NOT_OPERATIONAL)
589 continue;
590 info->cpu[info->configured].address = address;
591 info->configured++;
592 }
593 info->combined = info->configured;
594 }
595 return info;
596}
597
598static int smp_add_present_cpu(int cpu);
599
600static int __smp_rescan_cpus(struct sclp_cpu_info *info, int sysfs_add)
601{
602 struct pcpu *pcpu;
603 cpumask_t avail;
604 int cpu, nr, i;
605
606 nr = 0;
607 cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask);
608 cpu = cpumask_first(&avail);
609 for (i = 0; (i < info->combined) && (cpu < nr_cpu_ids); i++) {
610 if (info->has_cpu_type && info->cpu[i].type != boot_cpu_type)
611 continue;
612 if (pcpu_find_address(cpu_present_mask, info->cpu[i].address))
613 continue;
614 pcpu = pcpu_devices + cpu;
615 pcpu->address = info->cpu[i].address;
616 pcpu->state = (i >= info->configured) ?
617 CPU_STATE_STANDBY : CPU_STATE_CONFIGURED;
618 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
619 set_cpu_present(cpu, true);
620 if (sysfs_add && smp_add_present_cpu(cpu) != 0)
621 set_cpu_present(cpu, false);
622 else
623 nr++;
624 cpu = cpumask_next(cpu, &avail);
625 }
626 return nr;
627}
628
629static void __init smp_detect_cpus(void)
630{
631 unsigned int cpu, c_cpus, s_cpus;
632 struct sclp_cpu_info *info;
633
634 info = smp_get_cpu_info();
635 if (!info)
636 panic("smp_detect_cpus failed to allocate memory\n");
637 if (info->has_cpu_type) {
638 for (cpu = 0; cpu < info->combined; cpu++) {
639 if (info->cpu[cpu].address != boot_cpu_address)
640 continue;
641 /* The boot cpu dictates the cpu type. */
642 boot_cpu_type = info->cpu[cpu].type;
643 break;
644 }
645 }
646 c_cpus = s_cpus = 0;
647 for (cpu = 0; cpu < info->combined; cpu++) {
648 if (info->has_cpu_type && info->cpu[cpu].type != boot_cpu_type)
649 continue;
650 if (cpu < info->configured) {
651 smp_get_save_area(c_cpus, info->cpu[cpu].address);
652 c_cpus++;
653 } else
654 s_cpus++;
655 }
656 pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
657 get_online_cpus();
658 __smp_rescan_cpus(info, 0);
659 put_online_cpus();
660 kfree(info);
661}
662
663/*
664 * Activate a secondary processor.
665 */
666static void smp_start_secondary(void *cpuvoid)
667{
668 S390_lowcore.last_update_clock = get_tod_clock();
669 S390_lowcore.restart_stack = (unsigned long) restart_stack;
670 S390_lowcore.restart_fn = (unsigned long) do_restart;
671 S390_lowcore.restart_data = 0;
672 S390_lowcore.restart_source = -1UL;
673 restore_access_regs(S390_lowcore.access_regs_save_area);
674 __ctl_load(S390_lowcore.cregs_save_area, 0, 15);
675 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
676 cpu_init();
677 preempt_disable();
678 init_cpu_timer();
679 init_cpu_vtimer();
680 pfault_init();
681 notify_cpu_starting(smp_processor_id());
682 set_cpu_online(smp_processor_id(), true);
683 inc_irq_stat(CPU_RST);
684 local_irq_enable();
685 cpu_startup_entry(CPUHP_ONLINE);
686}
687
688/* Upping and downing of CPUs */
689int __cpu_up(unsigned int cpu, struct task_struct *tidle)
690{
691 struct pcpu *pcpu;
692 int rc;
693
694 pcpu = pcpu_devices + cpu;
695 if (pcpu->state != CPU_STATE_CONFIGURED)
696 return -EIO;
697 if (pcpu_sigp_retry(pcpu, SIGP_INITIAL_CPU_RESET, 0) !=
698 SIGP_CC_ORDER_CODE_ACCEPTED)
699 return -EIO;
700
701 rc = pcpu_alloc_lowcore(pcpu, cpu);
702 if (rc)
703 return rc;
704 pcpu_prepare_secondary(pcpu, cpu);
705 pcpu_attach_task(pcpu, tidle);
706 pcpu_start_fn(pcpu, smp_start_secondary, NULL);
707 while (!cpu_online(cpu))
708 cpu_relax();
709 return 0;
710}
711
712static unsigned int setup_possible_cpus __initdata;
713
714static int __init _setup_possible_cpus(char *s)
715{
716 get_option(&s, &setup_possible_cpus);
717 return 0;
718}
719early_param("possible_cpus", _setup_possible_cpus);
720
721#ifdef CONFIG_HOTPLUG_CPU
722
723int __cpu_disable(void)
724{
725 unsigned long cregs[16];
726
727 /* Handle possible pending IPIs */
728 smp_handle_ext_call();
729 set_cpu_online(smp_processor_id(), false);
730 /* Disable pseudo page faults on this cpu. */
731 pfault_fini();
732 /* Disable interrupt sources via control register. */
733 __ctl_store(cregs, 0, 15);
734 cregs[0] &= ~0x0000ee70UL; /* disable all external interrupts */
735 cregs[6] &= ~0xff000000UL; /* disable all I/O interrupts */
736 cregs[14] &= ~0x1f000000UL; /* disable most machine checks */
737 __ctl_load(cregs, 0, 15);
738 return 0;
739}
740
741void __cpu_die(unsigned int cpu)
742{
743 struct pcpu *pcpu;
744
745 /* Wait until target cpu is down */
746 pcpu = pcpu_devices + cpu;
747 while (!pcpu_stopped(pcpu))
748 cpu_relax();
749 pcpu_free_lowcore(pcpu);
750 atomic_dec(&init_mm.context.attach_count);
751 cpumask_clear_cpu(cpu, mm_cpumask(&init_mm));
752 if (MACHINE_HAS_TLB_LC)
753 cpumask_clear_cpu(cpu, &init_mm.context.cpu_attach_mask);
754}
755
756void __noreturn cpu_die(void)
757{
758 idle_task_exit();
759 pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0);
760 for (;;) ;
761}
762
763#endif /* CONFIG_HOTPLUG_CPU */
764
765void __init smp_fill_possible_mask(void)
766{
767 unsigned int possible, sclp, cpu;
768
769 sclp = sclp_get_max_cpu() ?: nr_cpu_ids;
770 possible = setup_possible_cpus ?: nr_cpu_ids;
771 possible = min(possible, sclp);
772 for (cpu = 0; cpu < possible && cpu < nr_cpu_ids; cpu++)
773 set_cpu_possible(cpu, true);
774}
775
776void __init smp_prepare_cpus(unsigned int max_cpus)
777{
778 /* request the 0x1201 emergency signal external interrupt */
779 if (register_external_irq(EXT_IRQ_EMERGENCY_SIG, do_ext_call_interrupt))
780 panic("Couldn't request external interrupt 0x1201");
781 /* request the 0x1202 external call external interrupt */
782 if (register_external_irq(EXT_IRQ_EXTERNAL_CALL, do_ext_call_interrupt))
783 panic("Couldn't request external interrupt 0x1202");
784 smp_detect_cpus();
785}
786
787void __init smp_prepare_boot_cpu(void)
788{
789 struct pcpu *pcpu = pcpu_devices;
790
791 boot_cpu_address = stap();
792 pcpu->state = CPU_STATE_CONFIGURED;
793 pcpu->address = boot_cpu_address;
794 pcpu->lowcore = (struct _lowcore *)(unsigned long) store_prefix();
795 pcpu->async_stack = S390_lowcore.async_stack - ASYNC_SIZE
796 + STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
797 pcpu->panic_stack = S390_lowcore.panic_stack - PAGE_SIZE
798 + STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
799 S390_lowcore.percpu_offset = __per_cpu_offset[0];
800 smp_cpu_set_polarization(0, POLARIZATION_UNKNOWN);
801 set_cpu_present(0, true);
802 set_cpu_online(0, true);
803}
804
805void __init smp_cpus_done(unsigned int max_cpus)
806{
807}
808
809void __init smp_setup_processor_id(void)
810{
811 S390_lowcore.cpu_nr = 0;
812}
813
814/*
815 * the frequency of the profiling timer can be changed
816 * by writing a multiplier value into /proc/profile.
817 *
818 * usually you want to run this on all CPUs ;)
819 */
820int setup_profiling_timer(unsigned int multiplier)
821{
822 return 0;
823}
824
825#ifdef CONFIG_HOTPLUG_CPU
826static ssize_t cpu_configure_show(struct device *dev,
827 struct device_attribute *attr, char *buf)
828{
829 ssize_t count;
830
831 mutex_lock(&smp_cpu_state_mutex);
832 count = sprintf(buf, "%d\n", pcpu_devices[dev->id].state);
833 mutex_unlock(&smp_cpu_state_mutex);
834 return count;
835}
836
837static ssize_t cpu_configure_store(struct device *dev,
838 struct device_attribute *attr,
839 const char *buf, size_t count)
840{
841 struct pcpu *pcpu;
842 int cpu, val, rc;
843 char delim;
844
845 if (sscanf(buf, "%d %c", &val, &delim) != 1)
846 return -EINVAL;
847 if (val != 0 && val != 1)
848 return -EINVAL;
849 get_online_cpus();
850 mutex_lock(&smp_cpu_state_mutex);
851 rc = -EBUSY;
852 /* disallow configuration changes of online cpus and cpu 0 */
853 cpu = dev->id;
854 if (cpu_online(cpu) || cpu == 0)
855 goto out;
856 pcpu = pcpu_devices + cpu;
857 rc = 0;
858 switch (val) {
859 case 0:
860 if (pcpu->state != CPU_STATE_CONFIGURED)
861 break;
862 rc = sclp_cpu_deconfigure(pcpu->address);
863 if (rc)
864 break;
865 pcpu->state = CPU_STATE_STANDBY;
866 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
867 topology_expect_change();
868 break;
869 case 1:
870 if (pcpu->state != CPU_STATE_STANDBY)
871 break;
872 rc = sclp_cpu_configure(pcpu->address);
873 if (rc)
874 break;
875 pcpu->state = CPU_STATE_CONFIGURED;
876 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
877 topology_expect_change();
878 break;
879 default:
880 break;
881 }
882out:
883 mutex_unlock(&smp_cpu_state_mutex);
884 put_online_cpus();
885 return rc ? rc : count;
886}
887static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
888#endif /* CONFIG_HOTPLUG_CPU */
889
890static ssize_t show_cpu_address(struct device *dev,
891 struct device_attribute *attr, char *buf)
892{
893 return sprintf(buf, "%d\n", pcpu_devices[dev->id].address);
894}
895static DEVICE_ATTR(address, 0444, show_cpu_address, NULL);
896
897static struct attribute *cpu_common_attrs[] = {
898#ifdef CONFIG_HOTPLUG_CPU
899 &dev_attr_configure.attr,
900#endif
901 &dev_attr_address.attr,
902 NULL,
903};
904
905static struct attribute_group cpu_common_attr_group = {
906 .attrs = cpu_common_attrs,
907};
908
909static ssize_t show_idle_count(struct device *dev,
910 struct device_attribute *attr, char *buf)
911{
912 struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id);
913 unsigned long long idle_count;
914 unsigned int sequence;
915
916 do {
917 sequence = ACCESS_ONCE(idle->sequence);
918 idle_count = ACCESS_ONCE(idle->idle_count);
919 if (ACCESS_ONCE(idle->clock_idle_enter))
920 idle_count++;
921 } while ((sequence & 1) || (ACCESS_ONCE(idle->sequence) != sequence));
922 return sprintf(buf, "%llu\n", idle_count);
923}
924static DEVICE_ATTR(idle_count, 0444, show_idle_count, NULL);
925
926static ssize_t show_idle_time(struct device *dev,
927 struct device_attribute *attr, char *buf)
928{
929 struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id);
930 unsigned long long now, idle_time, idle_enter, idle_exit;
931 unsigned int sequence;
932
933 do {
934 now = get_tod_clock();
935 sequence = ACCESS_ONCE(idle->sequence);
936 idle_time = ACCESS_ONCE(idle->idle_time);
937 idle_enter = ACCESS_ONCE(idle->clock_idle_enter);
938 idle_exit = ACCESS_ONCE(idle->clock_idle_exit);
939 } while ((sequence & 1) || (ACCESS_ONCE(idle->sequence) != sequence));
940 idle_time += idle_enter ? ((idle_exit ? : now) - idle_enter) : 0;
941 return sprintf(buf, "%llu\n", idle_time >> 12);
942}
943static DEVICE_ATTR(idle_time_us, 0444, show_idle_time, NULL);
944
945static struct attribute *cpu_online_attrs[] = {
946 &dev_attr_idle_count.attr,
947 &dev_attr_idle_time_us.attr,
948 NULL,
949};
950
951static struct attribute_group cpu_online_attr_group = {
952 .attrs = cpu_online_attrs,
953};
954
955static int smp_cpu_notify(struct notifier_block *self, unsigned long action,
956 void *hcpu)
957{
958 unsigned int cpu = (unsigned int)(long)hcpu;
959 struct cpu *c = pcpu_devices[cpu].cpu;
960 struct device *s = &c->dev;
961 int err = 0;
962
963 switch (action & ~CPU_TASKS_FROZEN) {
964 case CPU_ONLINE:
965 err = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
966 break;
967 case CPU_DEAD:
968 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
969 break;
970 }
971 return notifier_from_errno(err);
972}
973
974static int smp_add_present_cpu(int cpu)
975{
976 struct device *s;
977 struct cpu *c;
978 int rc;
979
980 c = kzalloc(sizeof(*c), GFP_KERNEL);
981 if (!c)
982 return -ENOMEM;
983 pcpu_devices[cpu].cpu = c;
984 s = &c->dev;
985 c->hotpluggable = 1;
986 rc = register_cpu(c, cpu);
987 if (rc)
988 goto out;
989 rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
990 if (rc)
991 goto out_cpu;
992 if (cpu_online(cpu)) {
993 rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
994 if (rc)
995 goto out_online;
996 }
997 rc = topology_cpu_init(c);
998 if (rc)
999 goto out_topology;
1000 return 0;
1001
1002out_topology:
1003 if (cpu_online(cpu))
1004 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
1005out_online:
1006 sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
1007out_cpu:
1008#ifdef CONFIG_HOTPLUG_CPU
1009 unregister_cpu(c);
1010#endif
1011out:
1012 return rc;
1013}
1014
1015#ifdef CONFIG_HOTPLUG_CPU
1016
1017int __ref smp_rescan_cpus(void)
1018{
1019 struct sclp_cpu_info *info;
1020 int nr;
1021
1022 info = smp_get_cpu_info();
1023 if (!info)
1024 return -ENOMEM;
1025 get_online_cpus();
1026 mutex_lock(&smp_cpu_state_mutex);
1027 nr = __smp_rescan_cpus(info, 1);
1028 mutex_unlock(&smp_cpu_state_mutex);
1029 put_online_cpus();
1030 kfree(info);
1031 if (nr)
1032 topology_schedule_update();
1033 return 0;
1034}
1035
1036static ssize_t __ref rescan_store(struct device *dev,
1037 struct device_attribute *attr,
1038 const char *buf,
1039 size_t count)
1040{
1041 int rc;
1042
1043 rc = smp_rescan_cpus();
1044 return rc ? rc : count;
1045}
1046static DEVICE_ATTR(rescan, 0200, NULL, rescan_store);
1047#endif /* CONFIG_HOTPLUG_CPU */
1048
1049static int __init s390_smp_init(void)
1050{
1051 int cpu, rc = 0;
1052
1053#ifdef CONFIG_HOTPLUG_CPU
1054 rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan);
1055 if (rc)
1056 return rc;
1057#endif
1058 cpu_notifier_register_begin();
1059 for_each_present_cpu(cpu) {
1060 rc = smp_add_present_cpu(cpu);
1061 if (rc)
1062 goto out;
1063 }
1064
1065 __hotcpu_notifier(smp_cpu_notify, 0);
1066
1067out:
1068 cpu_notifier_register_done();
1069 return rc;
1070}
1071subsys_initcall(s390_smp_init);