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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/bootmem.h>
23#include <linux/module.h>
24#include <linux/init.h>
25#include <linux/mm.h>
26#include <linux/err.h>
27#include <linux/spinlock.h>
28#include <linux/kernel_stat.h>
29#include <linux/delay.h>
30#include <linux/interrupt.h>
31#include <linux/irqflags.h>
32#include <linux/cpu.h>
33#include <linux/slab.h>
34#include <linux/crash_dump.h>
35#include <linux/memblock.h>
36#include <asm/asm-offsets.h>
37#include <asm/diag.h>
38#include <asm/switch_to.h>
39#include <asm/facility.h>
40#include <asm/ipl.h>
41#include <asm/setup.h>
42#include <asm/irq.h>
43#include <asm/tlbflush.h>
44#include <asm/vtimer.h>
45#include <asm/lowcore.h>
46#include <asm/sclp.h>
47#include <asm/vdso.h>
48#include <asm/debug.h>
49#include <asm/os_info.h>
50#include <asm/sigp.h>
51#include <asm/idle.h>
52#include "entry.h"
53
54enum {
55 ec_schedule = 0,
56 ec_call_function_single,
57 ec_stop_cpu,
58};
59
60enum {
61 CPU_STATE_STANDBY,
62 CPU_STATE_CONFIGURED,
63};
64
65static DEFINE_PER_CPU(struct cpu *, cpu_device);
66
67struct pcpu {
68 struct lowcore *lowcore; /* lowcore page(s) for the cpu */
69 unsigned long ec_mask; /* bit mask for ec_xxx functions */
70 unsigned long ec_clk; /* sigp timestamp for ec_xxx */
71 signed char state; /* physical cpu state */
72 signed char polarization; /* physical polarization */
73 u16 address; /* physical cpu address */
74};
75
76static u8 boot_core_type;
77static struct pcpu pcpu_devices[NR_CPUS];
78
79unsigned int smp_cpu_mt_shift;
80EXPORT_SYMBOL(smp_cpu_mt_shift);
81
82unsigned int smp_cpu_mtid;
83EXPORT_SYMBOL(smp_cpu_mtid);
84
85#ifdef CONFIG_CRASH_DUMP
86__vector128 __initdata boot_cpu_vector_save_area[__NUM_VXRS];
87#endif
88
89static unsigned int smp_max_threads __initdata = -1U;
90
91static int __init early_nosmt(char *s)
92{
93 smp_max_threads = 1;
94 return 0;
95}
96early_param("nosmt", early_nosmt);
97
98static int __init early_smt(char *s)
99{
100 get_option(&s, &smp_max_threads);
101 return 0;
102}
103early_param("smt", early_smt);
104
105/*
106 * The smp_cpu_state_mutex must be held when changing the state or polarization
107 * member of a pcpu data structure within the pcpu_devices arreay.
108 */
109DEFINE_MUTEX(smp_cpu_state_mutex);
110
111/*
112 * Signal processor helper functions.
113 */
114static inline int __pcpu_sigp_relax(u16 addr, u8 order, unsigned long parm)
115{
116 int cc;
117
118 while (1) {
119 cc = __pcpu_sigp(addr, order, parm, NULL);
120 if (cc != SIGP_CC_BUSY)
121 return cc;
122 cpu_relax();
123 }
124}
125
126static int pcpu_sigp_retry(struct pcpu *pcpu, u8 order, u32 parm)
127{
128 int cc, retry;
129
130 for (retry = 0; ; retry++) {
131 cc = __pcpu_sigp(pcpu->address, order, parm, NULL);
132 if (cc != SIGP_CC_BUSY)
133 break;
134 if (retry >= 3)
135 udelay(10);
136 }
137 return cc;
138}
139
140static inline int pcpu_stopped(struct pcpu *pcpu)
141{
142 u32 uninitialized_var(status);
143
144 if (__pcpu_sigp(pcpu->address, SIGP_SENSE,
145 0, &status) != SIGP_CC_STATUS_STORED)
146 return 0;
147 return !!(status & (SIGP_STATUS_CHECK_STOP|SIGP_STATUS_STOPPED));
148}
149
150static inline int pcpu_running(struct pcpu *pcpu)
151{
152 if (__pcpu_sigp(pcpu->address, SIGP_SENSE_RUNNING,
153 0, NULL) != SIGP_CC_STATUS_STORED)
154 return 1;
155 /* Status stored condition code is equivalent to cpu not running. */
156 return 0;
157}
158
159/*
160 * Find struct pcpu by cpu address.
161 */
162static struct pcpu *pcpu_find_address(const struct cpumask *mask, u16 address)
163{
164 int cpu;
165
166 for_each_cpu(cpu, mask)
167 if (pcpu_devices[cpu].address == address)
168 return pcpu_devices + cpu;
169 return NULL;
170}
171
172static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit)
173{
174 int order;
175
176 if (test_and_set_bit(ec_bit, &pcpu->ec_mask))
177 return;
178 order = pcpu_running(pcpu) ? SIGP_EXTERNAL_CALL : SIGP_EMERGENCY_SIGNAL;
179 pcpu->ec_clk = get_tod_clock_fast();
180 pcpu_sigp_retry(pcpu, order, 0);
181}
182
183#define ASYNC_FRAME_OFFSET (ASYNC_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE)
184#define PANIC_FRAME_OFFSET (PAGE_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE)
185
186static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
187{
188 unsigned long async_stack, panic_stack;
189 struct lowcore *lc;
190
191 if (pcpu != &pcpu_devices[0]) {
192 pcpu->lowcore = (struct lowcore *)
193 __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
194 async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
195 panic_stack = __get_free_page(GFP_KERNEL);
196 if (!pcpu->lowcore || !panic_stack || !async_stack)
197 goto out;
198 } else {
199 async_stack = pcpu->lowcore->async_stack - ASYNC_FRAME_OFFSET;
200 panic_stack = pcpu->lowcore->panic_stack - PANIC_FRAME_OFFSET;
201 }
202 lc = pcpu->lowcore;
203 memcpy(lc, &S390_lowcore, 512);
204 memset((char *) lc + 512, 0, sizeof(*lc) - 512);
205 lc->async_stack = async_stack + ASYNC_FRAME_OFFSET;
206 lc->panic_stack = panic_stack + PANIC_FRAME_OFFSET;
207 lc->cpu_nr = cpu;
208 lc->spinlock_lockval = arch_spin_lockval(cpu);
209 if (MACHINE_HAS_VX)
210 lc->vector_save_area_addr =
211 (unsigned long) &lc->vector_save_area;
212 if (vdso_alloc_per_cpu(lc))
213 goto out;
214 lowcore_ptr[cpu] = lc;
215 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, (u32)(unsigned long) lc);
216 return 0;
217out:
218 if (pcpu != &pcpu_devices[0]) {
219 free_page(panic_stack);
220 free_pages(async_stack, ASYNC_ORDER);
221 free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
222 }
223 return -ENOMEM;
224}
225
226#ifdef CONFIG_HOTPLUG_CPU
227
228static void pcpu_free_lowcore(struct pcpu *pcpu)
229{
230 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0);
231 lowcore_ptr[pcpu - pcpu_devices] = NULL;
232 vdso_free_per_cpu(pcpu->lowcore);
233 if (pcpu == &pcpu_devices[0])
234 return;
235 free_page(pcpu->lowcore->panic_stack-PANIC_FRAME_OFFSET);
236 free_pages(pcpu->lowcore->async_stack-ASYNC_FRAME_OFFSET, ASYNC_ORDER);
237 free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
238}
239
240#endif /* CONFIG_HOTPLUG_CPU */
241
242static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu)
243{
244 struct lowcore *lc = pcpu->lowcore;
245
246 cpumask_set_cpu(cpu, &init_mm.context.cpu_attach_mask);
247 cpumask_set_cpu(cpu, mm_cpumask(&init_mm));
248 lc->cpu_nr = cpu;
249 lc->spinlock_lockval = arch_spin_lockval(cpu);
250 lc->percpu_offset = __per_cpu_offset[cpu];
251 lc->kernel_asce = S390_lowcore.kernel_asce;
252 lc->machine_flags = S390_lowcore.machine_flags;
253 lc->user_timer = lc->system_timer = lc->steal_timer = 0;
254 __ctl_store(lc->cregs_save_area, 0, 15);
255 save_access_regs((unsigned int *) lc->access_regs_save_area);
256 memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,
257 MAX_FACILITY_BIT/8);
258}
259
260static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk)
261{
262 struct lowcore *lc = pcpu->lowcore;
263
264 lc->kernel_stack = (unsigned long) task_stack_page(tsk)
265 + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
266 lc->current_task = (unsigned long) tsk;
267 lc->lpp = LPP_MAGIC;
268 lc->current_pid = tsk->pid;
269 lc->user_timer = tsk->thread.user_timer;
270 lc->system_timer = tsk->thread.system_timer;
271 lc->steal_timer = 0;
272}
273
274static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data)
275{
276 struct lowcore *lc = pcpu->lowcore;
277
278 lc->restart_stack = lc->kernel_stack;
279 lc->restart_fn = (unsigned long) func;
280 lc->restart_data = (unsigned long) data;
281 lc->restart_source = -1UL;
282 pcpu_sigp_retry(pcpu, SIGP_RESTART, 0);
283}
284
285/*
286 * Call function via PSW restart on pcpu and stop the current cpu.
287 */
288static void pcpu_delegate(struct pcpu *pcpu, void (*func)(void *),
289 void *data, unsigned long stack)
290{
291 struct lowcore *lc = lowcore_ptr[pcpu - pcpu_devices];
292 unsigned long source_cpu = stap();
293
294 __load_psw_mask(PSW_KERNEL_BITS);
295 if (pcpu->address == source_cpu)
296 func(data); /* should not return */
297 /* Stop target cpu (if func returns this stops the current cpu). */
298 pcpu_sigp_retry(pcpu, SIGP_STOP, 0);
299 /* Restart func on the target cpu and stop the current cpu. */
300 mem_assign_absolute(lc->restart_stack, stack);
301 mem_assign_absolute(lc->restart_fn, (unsigned long) func);
302 mem_assign_absolute(lc->restart_data, (unsigned long) data);
303 mem_assign_absolute(lc->restart_source, source_cpu);
304 asm volatile(
305 "0: sigp 0,%0,%2 # sigp restart to target cpu\n"
306 " brc 2,0b # busy, try again\n"
307 "1: sigp 0,%1,%3 # sigp stop to current cpu\n"
308 " brc 2,1b # busy, try again\n"
309 : : "d" (pcpu->address), "d" (source_cpu),
310 "K" (SIGP_RESTART), "K" (SIGP_STOP)
311 : "0", "1", "cc");
312 for (;;) ;
313}
314
315/*
316 * Enable additional logical cpus for multi-threading.
317 */
318static int pcpu_set_smt(unsigned int mtid)
319{
320 int cc;
321
322 if (smp_cpu_mtid == mtid)
323 return 0;
324 cc = __pcpu_sigp(0, SIGP_SET_MULTI_THREADING, mtid, NULL);
325 if (cc == 0) {
326 smp_cpu_mtid = mtid;
327 smp_cpu_mt_shift = 0;
328 while (smp_cpu_mtid >= (1U << smp_cpu_mt_shift))
329 smp_cpu_mt_shift++;
330 pcpu_devices[0].address = stap();
331 }
332 return cc;
333}
334
335/*
336 * Call function on an online CPU.
337 */
338void smp_call_online_cpu(void (*func)(void *), void *data)
339{
340 struct pcpu *pcpu;
341
342 /* Use the current cpu if it is online. */
343 pcpu = pcpu_find_address(cpu_online_mask, stap());
344 if (!pcpu)
345 /* Use the first online cpu. */
346 pcpu = pcpu_devices + cpumask_first(cpu_online_mask);
347 pcpu_delegate(pcpu, func, data, (unsigned long) restart_stack);
348}
349
350/*
351 * Call function on the ipl CPU.
352 */
353void smp_call_ipl_cpu(void (*func)(void *), void *data)
354{
355 pcpu_delegate(&pcpu_devices[0], func, data,
356 pcpu_devices->lowcore->panic_stack -
357 PANIC_FRAME_OFFSET + PAGE_SIZE);
358}
359
360int smp_find_processor_id(u16 address)
361{
362 int cpu;
363
364 for_each_present_cpu(cpu)
365 if (pcpu_devices[cpu].address == address)
366 return cpu;
367 return -1;
368}
369
370bool arch_vcpu_is_preempted(int cpu)
371{
372 if (test_cpu_flag_of(CIF_ENABLED_WAIT, cpu))
373 return false;
374 if (pcpu_running(pcpu_devices + cpu))
375 return false;
376 return true;
377}
378EXPORT_SYMBOL(arch_vcpu_is_preempted);
379
380void smp_yield_cpu(int cpu)
381{
382 if (MACHINE_HAS_DIAG9C) {
383 diag_stat_inc_norecursion(DIAG_STAT_X09C);
384 asm volatile("diag %0,0,0x9c"
385 : : "d" (pcpu_devices[cpu].address));
386 } else if (MACHINE_HAS_DIAG44) {
387 diag_stat_inc_norecursion(DIAG_STAT_X044);
388 asm volatile("diag 0,0,0x44");
389 }
390}
391
392/*
393 * Send cpus emergency shutdown signal. This gives the cpus the
394 * opportunity to complete outstanding interrupts.
395 */
396static void smp_emergency_stop(cpumask_t *cpumask)
397{
398 u64 end;
399 int cpu;
400
401 end = get_tod_clock() + (1000000UL << 12);
402 for_each_cpu(cpu, cpumask) {
403 struct pcpu *pcpu = pcpu_devices + cpu;
404 set_bit(ec_stop_cpu, &pcpu->ec_mask);
405 while (__pcpu_sigp(pcpu->address, SIGP_EMERGENCY_SIGNAL,
406 0, NULL) == SIGP_CC_BUSY &&
407 get_tod_clock() < end)
408 cpu_relax();
409 }
410 while (get_tod_clock() < end) {
411 for_each_cpu(cpu, cpumask)
412 if (pcpu_stopped(pcpu_devices + cpu))
413 cpumask_clear_cpu(cpu, cpumask);
414 if (cpumask_empty(cpumask))
415 break;
416 cpu_relax();
417 }
418}
419
420/*
421 * Stop all cpus but the current one.
422 */
423void smp_send_stop(void)
424{
425 cpumask_t cpumask;
426 int cpu;
427
428 /* Disable all interrupts/machine checks */
429 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
430 trace_hardirqs_off();
431
432 debug_set_critical();
433 cpumask_copy(&cpumask, cpu_online_mask);
434 cpumask_clear_cpu(smp_processor_id(), &cpumask);
435
436 if (oops_in_progress)
437 smp_emergency_stop(&cpumask);
438
439 /* stop all processors */
440 for_each_cpu(cpu, &cpumask) {
441 struct pcpu *pcpu = pcpu_devices + cpu;
442 pcpu_sigp_retry(pcpu, SIGP_STOP, 0);
443 while (!pcpu_stopped(pcpu))
444 cpu_relax();
445 }
446}
447
448/*
449 * This is the main routine where commands issued by other
450 * cpus are handled.
451 */
452static void smp_handle_ext_call(void)
453{
454 unsigned long bits;
455
456 /* handle bit signal external calls */
457 bits = xchg(&pcpu_devices[smp_processor_id()].ec_mask, 0);
458 if (test_bit(ec_stop_cpu, &bits))
459 smp_stop_cpu();
460 if (test_bit(ec_schedule, &bits))
461 scheduler_ipi();
462 if (test_bit(ec_call_function_single, &bits))
463 generic_smp_call_function_single_interrupt();
464}
465
466static void do_ext_call_interrupt(struct ext_code ext_code,
467 unsigned int param32, unsigned long param64)
468{
469 inc_irq_stat(ext_code.code == 0x1202 ? IRQEXT_EXC : IRQEXT_EMS);
470 smp_handle_ext_call();
471}
472
473void arch_send_call_function_ipi_mask(const struct cpumask *mask)
474{
475 int cpu;
476
477 for_each_cpu(cpu, mask)
478 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
479}
480
481void arch_send_call_function_single_ipi(int cpu)
482{
483 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
484}
485
486/*
487 * this function sends a 'reschedule' IPI to another CPU.
488 * it goes straight through and wastes no time serializing
489 * anything. Worst case is that we lose a reschedule ...
490 */
491void smp_send_reschedule(int cpu)
492{
493 pcpu_ec_call(pcpu_devices + cpu, ec_schedule);
494}
495
496/*
497 * parameter area for the set/clear control bit callbacks
498 */
499struct ec_creg_mask_parms {
500 unsigned long orval;
501 unsigned long andval;
502 int cr;
503};
504
505/*
506 * callback for setting/clearing control bits
507 */
508static void smp_ctl_bit_callback(void *info)
509{
510 struct ec_creg_mask_parms *pp = info;
511 unsigned long cregs[16];
512
513 __ctl_store(cregs, 0, 15);
514 cregs[pp->cr] = (cregs[pp->cr] & pp->andval) | pp->orval;
515 __ctl_load(cregs, 0, 15);
516}
517
518/*
519 * Set a bit in a control register of all cpus
520 */
521void smp_ctl_set_bit(int cr, int bit)
522{
523 struct ec_creg_mask_parms parms = { 1UL << bit, -1UL, cr };
524
525 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
526}
527EXPORT_SYMBOL(smp_ctl_set_bit);
528
529/*
530 * Clear a bit in a control register of all cpus
531 */
532void smp_ctl_clear_bit(int cr, int bit)
533{
534 struct ec_creg_mask_parms parms = { 0, ~(1UL << bit), cr };
535
536 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
537}
538EXPORT_SYMBOL(smp_ctl_clear_bit);
539
540#ifdef CONFIG_CRASH_DUMP
541
542int smp_store_status(int cpu)
543{
544 struct pcpu *pcpu = pcpu_devices + cpu;
545 unsigned long pa;
546
547 pa = __pa(&pcpu->lowcore->floating_pt_save_area);
548 if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_STATUS_AT_ADDRESS,
549 pa) != SIGP_CC_ORDER_CODE_ACCEPTED)
550 return -EIO;
551 if (!MACHINE_HAS_VX)
552 return 0;
553 pa = __pa(pcpu->lowcore->vector_save_area_addr);
554 if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_ADDITIONAL_STATUS,
555 pa) != SIGP_CC_ORDER_CODE_ACCEPTED)
556 return -EIO;
557 return 0;
558}
559
560/*
561 * Collect CPU state of the previous, crashed system.
562 * There are four cases:
563 * 1) standard zfcp dump
564 * condition: OLDMEM_BASE == NULL && ipl_info.type == IPL_TYPE_FCP_DUMP
565 * The state for all CPUs except the boot CPU needs to be collected
566 * with sigp stop-and-store-status. The boot CPU state is located in
567 * the absolute lowcore of the memory stored in the HSA. The zcore code
568 * will copy the boot CPU state from the HSA.
569 * 2) stand-alone kdump for SCSI (zfcp dump with swapped memory)
570 * condition: OLDMEM_BASE != NULL && ipl_info.type == IPL_TYPE_FCP_DUMP
571 * The state for all CPUs except the boot CPU needs to be collected
572 * with sigp stop-and-store-status. The firmware or the boot-loader
573 * stored the registers of the boot CPU in the absolute lowcore in the
574 * memory of the old system.
575 * 3) kdump and the old kernel did not store the CPU state,
576 * or stand-alone kdump for DASD
577 * condition: OLDMEM_BASE != NULL && !is_kdump_kernel()
578 * The state for all CPUs except the boot CPU needs to be collected
579 * with sigp stop-and-store-status. The kexec code or the boot-loader
580 * stored the registers of the boot CPU in the memory of the old system.
581 * 4) kdump and the old kernel stored the CPU state
582 * condition: OLDMEM_BASE != NULL && is_kdump_kernel()
583 * This case does not exist for s390 anymore, setup_arch explicitly
584 * deactivates the elfcorehdr= kernel parameter
585 */
586static __init void smp_save_cpu_vxrs(struct save_area *sa, u16 addr,
587 bool is_boot_cpu, unsigned long page)
588{
589 __vector128 *vxrs = (__vector128 *) page;
590
591 if (is_boot_cpu)
592 vxrs = boot_cpu_vector_save_area;
593 else
594 __pcpu_sigp_relax(addr, SIGP_STORE_ADDITIONAL_STATUS, page);
595 save_area_add_vxrs(sa, vxrs);
596}
597
598static __init void smp_save_cpu_regs(struct save_area *sa, u16 addr,
599 bool is_boot_cpu, unsigned long page)
600{
601 void *regs = (void *) page;
602
603 if (is_boot_cpu)
604 copy_oldmem_kernel(regs, (void *) __LC_FPREGS_SAVE_AREA, 512);
605 else
606 __pcpu_sigp_relax(addr, SIGP_STORE_STATUS_AT_ADDRESS, page);
607 save_area_add_regs(sa, regs);
608}
609
610void __init smp_save_dump_cpus(void)
611{
612 int addr, boot_cpu_addr, max_cpu_addr;
613 struct save_area *sa;
614 unsigned long page;
615 bool is_boot_cpu;
616
617 if (!(OLDMEM_BASE || ipl_info.type == IPL_TYPE_FCP_DUMP))
618 /* No previous system present, normal boot. */
619 return;
620 /* Allocate a page as dumping area for the store status sigps */
621 page = memblock_alloc_base(PAGE_SIZE, PAGE_SIZE, 1UL << 31);
622 /* Set multi-threading state to the previous system. */
623 pcpu_set_smt(sclp.mtid_prev);
624 boot_cpu_addr = stap();
625 max_cpu_addr = SCLP_MAX_CORES << sclp.mtid_prev;
626 for (addr = 0; addr <= max_cpu_addr; addr++) {
627 if (__pcpu_sigp_relax(addr, SIGP_SENSE, 0) ==
628 SIGP_CC_NOT_OPERATIONAL)
629 continue;
630 is_boot_cpu = (addr == boot_cpu_addr);
631 /* Allocate save area */
632 sa = save_area_alloc(is_boot_cpu);
633 if (!sa)
634 panic("could not allocate memory for save area\n");
635 if (MACHINE_HAS_VX)
636 /* Get the vector registers */
637 smp_save_cpu_vxrs(sa, addr, is_boot_cpu, page);
638 /*
639 * For a zfcp dump OLDMEM_BASE == NULL and the registers
640 * of the boot CPU are stored in the HSA. To retrieve
641 * these registers an SCLP request is required which is
642 * done by drivers/s390/char/zcore.c:init_cpu_info()
643 */
644 if (!is_boot_cpu || OLDMEM_BASE)
645 /* Get the CPU registers */
646 smp_save_cpu_regs(sa, addr, is_boot_cpu, page);
647 }
648 memblock_free(page, PAGE_SIZE);
649 diag308_reset();
650 pcpu_set_smt(0);
651}
652#endif /* CONFIG_CRASH_DUMP */
653
654void smp_cpu_set_polarization(int cpu, int val)
655{
656 pcpu_devices[cpu].polarization = val;
657}
658
659int smp_cpu_get_polarization(int cpu)
660{
661 return pcpu_devices[cpu].polarization;
662}
663
664static void __ref smp_get_core_info(struct sclp_core_info *info, int early)
665{
666 static int use_sigp_detection;
667 int address;
668
669 if (use_sigp_detection || sclp_get_core_info(info, early)) {
670 use_sigp_detection = 1;
671 for (address = 0;
672 address < (SCLP_MAX_CORES << smp_cpu_mt_shift);
673 address += (1U << smp_cpu_mt_shift)) {
674 if (__pcpu_sigp_relax(address, SIGP_SENSE, 0) ==
675 SIGP_CC_NOT_OPERATIONAL)
676 continue;
677 info->core[info->configured].core_id =
678 address >> smp_cpu_mt_shift;
679 info->configured++;
680 }
681 info->combined = info->configured;
682 }
683}
684
685static int smp_add_present_cpu(int cpu);
686
687static int __smp_rescan_cpus(struct sclp_core_info *info, int sysfs_add)
688{
689 struct pcpu *pcpu;
690 cpumask_t avail;
691 int cpu, nr, i, j;
692 u16 address;
693
694 nr = 0;
695 cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask);
696 cpu = cpumask_first(&avail);
697 for (i = 0; (i < info->combined) && (cpu < nr_cpu_ids); i++) {
698 if (sclp.has_core_type && info->core[i].type != boot_core_type)
699 continue;
700 address = info->core[i].core_id << smp_cpu_mt_shift;
701 for (j = 0; j <= smp_cpu_mtid; j++) {
702 if (pcpu_find_address(cpu_present_mask, address + j))
703 continue;
704 pcpu = pcpu_devices + cpu;
705 pcpu->address = address + j;
706 pcpu->state =
707 (cpu >= info->configured*(smp_cpu_mtid + 1)) ?
708 CPU_STATE_STANDBY : CPU_STATE_CONFIGURED;
709 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
710 set_cpu_present(cpu, true);
711 if (sysfs_add && smp_add_present_cpu(cpu) != 0)
712 set_cpu_present(cpu, false);
713 else
714 nr++;
715 cpu = cpumask_next(cpu, &avail);
716 if (cpu >= nr_cpu_ids)
717 break;
718 }
719 }
720 return nr;
721}
722
723void __init smp_detect_cpus(void)
724{
725 unsigned int cpu, mtid, c_cpus, s_cpus;
726 struct sclp_core_info *info;
727 u16 address;
728
729 /* Get CPU information */
730 info = memblock_virt_alloc(sizeof(*info), 8);
731 smp_get_core_info(info, 1);
732 /* Find boot CPU type */
733 if (sclp.has_core_type) {
734 address = stap();
735 for (cpu = 0; cpu < info->combined; cpu++)
736 if (info->core[cpu].core_id == address) {
737 /* The boot cpu dictates the cpu type. */
738 boot_core_type = info->core[cpu].type;
739 break;
740 }
741 if (cpu >= info->combined)
742 panic("Could not find boot CPU type");
743 }
744
745 /* Set multi-threading state for the current system */
746 mtid = boot_core_type ? sclp.mtid : sclp.mtid_cp;
747 mtid = (mtid < smp_max_threads) ? mtid : smp_max_threads - 1;
748 pcpu_set_smt(mtid);
749
750 /* Print number of CPUs */
751 c_cpus = s_cpus = 0;
752 for (cpu = 0; cpu < info->combined; cpu++) {
753 if (sclp.has_core_type &&
754 info->core[cpu].type != boot_core_type)
755 continue;
756 if (cpu < info->configured)
757 c_cpus += smp_cpu_mtid + 1;
758 else
759 s_cpus += smp_cpu_mtid + 1;
760 }
761 pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
762
763 /* Add CPUs present at boot */
764 get_online_cpus();
765 __smp_rescan_cpus(info, 0);
766 put_online_cpus();
767 memblock_free_early((unsigned long)info, sizeof(*info));
768}
769
770/*
771 * Activate a secondary processor.
772 */
773static void smp_start_secondary(void *cpuvoid)
774{
775 S390_lowcore.last_update_clock = get_tod_clock();
776 S390_lowcore.restart_stack = (unsigned long) restart_stack;
777 S390_lowcore.restart_fn = (unsigned long) do_restart;
778 S390_lowcore.restart_data = 0;
779 S390_lowcore.restart_source = -1UL;
780 restore_access_regs(S390_lowcore.access_regs_save_area);
781 __ctl_load(S390_lowcore.cregs_save_area, 0, 15);
782 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
783 cpu_init();
784 preempt_disable();
785 init_cpu_timer();
786 vtime_init();
787 pfault_init();
788 notify_cpu_starting(smp_processor_id());
789 set_cpu_online(smp_processor_id(), true);
790 inc_irq_stat(CPU_RST);
791 local_irq_enable();
792 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
793}
794
795/* Upping and downing of CPUs */
796int __cpu_up(unsigned int cpu, struct task_struct *tidle)
797{
798 struct pcpu *pcpu;
799 int base, i, rc;
800
801 pcpu = pcpu_devices + cpu;
802 if (pcpu->state != CPU_STATE_CONFIGURED)
803 return -EIO;
804 base = smp_get_base_cpu(cpu);
805 for (i = 0; i <= smp_cpu_mtid; i++) {
806 if (base + i < nr_cpu_ids)
807 if (cpu_online(base + i))
808 break;
809 }
810 /*
811 * If this is the first CPU of the core to get online
812 * do an initial CPU reset.
813 */
814 if (i > smp_cpu_mtid &&
815 pcpu_sigp_retry(pcpu_devices + base, SIGP_INITIAL_CPU_RESET, 0) !=
816 SIGP_CC_ORDER_CODE_ACCEPTED)
817 return -EIO;
818
819 rc = pcpu_alloc_lowcore(pcpu, cpu);
820 if (rc)
821 return rc;
822 pcpu_prepare_secondary(pcpu, cpu);
823 pcpu_attach_task(pcpu, tidle);
824 pcpu_start_fn(pcpu, smp_start_secondary, NULL);
825 /* Wait until cpu puts itself in the online & active maps */
826 while (!cpu_online(cpu))
827 cpu_relax();
828 return 0;
829}
830
831static unsigned int setup_possible_cpus __initdata;
832
833static int __init _setup_possible_cpus(char *s)
834{
835 get_option(&s, &setup_possible_cpus);
836 return 0;
837}
838early_param("possible_cpus", _setup_possible_cpus);
839
840#ifdef CONFIG_HOTPLUG_CPU
841
842int __cpu_disable(void)
843{
844 unsigned long cregs[16];
845
846 /* Handle possible pending IPIs */
847 smp_handle_ext_call();
848 set_cpu_online(smp_processor_id(), false);
849 /* Disable pseudo page faults on this cpu. */
850 pfault_fini();
851 /* Disable interrupt sources via control register. */
852 __ctl_store(cregs, 0, 15);
853 cregs[0] &= ~0x0000ee70UL; /* disable all external interrupts */
854 cregs[6] &= ~0xff000000UL; /* disable all I/O interrupts */
855 cregs[14] &= ~0x1f000000UL; /* disable most machine checks */
856 __ctl_load(cregs, 0, 15);
857 clear_cpu_flag(CIF_NOHZ_DELAY);
858 return 0;
859}
860
861void __cpu_die(unsigned int cpu)
862{
863 struct pcpu *pcpu;
864
865 /* Wait until target cpu is down */
866 pcpu = pcpu_devices + cpu;
867 while (!pcpu_stopped(pcpu))
868 cpu_relax();
869 pcpu_free_lowcore(pcpu);
870 cpumask_clear_cpu(cpu, mm_cpumask(&init_mm));
871 cpumask_clear_cpu(cpu, &init_mm.context.cpu_attach_mask);
872}
873
874void __noreturn cpu_die(void)
875{
876 idle_task_exit();
877 pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0);
878 for (;;) ;
879}
880
881#endif /* CONFIG_HOTPLUG_CPU */
882
883void __init smp_fill_possible_mask(void)
884{
885 unsigned int possible, sclp_max, cpu;
886
887 sclp_max = max(sclp.mtid, sclp.mtid_cp) + 1;
888 sclp_max = min(smp_max_threads, sclp_max);
889 sclp_max = (sclp.max_cores * sclp_max) ?: nr_cpu_ids;
890 possible = setup_possible_cpus ?: nr_cpu_ids;
891 possible = min(possible, sclp_max);
892 for (cpu = 0; cpu < possible && cpu < nr_cpu_ids; cpu++)
893 set_cpu_possible(cpu, true);
894}
895
896void __init smp_prepare_cpus(unsigned int max_cpus)
897{
898 /* request the 0x1201 emergency signal external interrupt */
899 if (register_external_irq(EXT_IRQ_EMERGENCY_SIG, do_ext_call_interrupt))
900 panic("Couldn't request external interrupt 0x1201");
901 /* request the 0x1202 external call external interrupt */
902 if (register_external_irq(EXT_IRQ_EXTERNAL_CALL, do_ext_call_interrupt))
903 panic("Couldn't request external interrupt 0x1202");
904}
905
906void __init smp_prepare_boot_cpu(void)
907{
908 struct pcpu *pcpu = pcpu_devices;
909
910 pcpu->state = CPU_STATE_CONFIGURED;
911 pcpu->address = stap();
912 pcpu->lowcore = (struct lowcore *)(unsigned long) store_prefix();
913 S390_lowcore.percpu_offset = __per_cpu_offset[0];
914 smp_cpu_set_polarization(0, POLARIZATION_UNKNOWN);
915 set_cpu_present(0, true);
916 set_cpu_online(0, true);
917}
918
919void __init smp_cpus_done(unsigned int max_cpus)
920{
921}
922
923void __init smp_setup_processor_id(void)
924{
925 S390_lowcore.cpu_nr = 0;
926 S390_lowcore.spinlock_lockval = arch_spin_lockval(0);
927}
928
929/*
930 * the frequency of the profiling timer can be changed
931 * by writing a multiplier value into /proc/profile.
932 *
933 * usually you want to run this on all CPUs ;)
934 */
935int setup_profiling_timer(unsigned int multiplier)
936{
937 return 0;
938}
939
940#ifdef CONFIG_HOTPLUG_CPU
941static ssize_t cpu_configure_show(struct device *dev,
942 struct device_attribute *attr, char *buf)
943{
944 ssize_t count;
945
946 mutex_lock(&smp_cpu_state_mutex);
947 count = sprintf(buf, "%d\n", pcpu_devices[dev->id].state);
948 mutex_unlock(&smp_cpu_state_mutex);
949 return count;
950}
951
952static ssize_t cpu_configure_store(struct device *dev,
953 struct device_attribute *attr,
954 const char *buf, size_t count)
955{
956 struct pcpu *pcpu;
957 int cpu, val, rc, i;
958 char delim;
959
960 if (sscanf(buf, "%d %c", &val, &delim) != 1)
961 return -EINVAL;
962 if (val != 0 && val != 1)
963 return -EINVAL;
964 get_online_cpus();
965 mutex_lock(&smp_cpu_state_mutex);
966 rc = -EBUSY;
967 /* disallow configuration changes of online cpus and cpu 0 */
968 cpu = dev->id;
969 cpu = smp_get_base_cpu(cpu);
970 if (cpu == 0)
971 goto out;
972 for (i = 0; i <= smp_cpu_mtid; i++)
973 if (cpu_online(cpu + i))
974 goto out;
975 pcpu = pcpu_devices + cpu;
976 rc = 0;
977 switch (val) {
978 case 0:
979 if (pcpu->state != CPU_STATE_CONFIGURED)
980 break;
981 rc = sclp_core_deconfigure(pcpu->address >> smp_cpu_mt_shift);
982 if (rc)
983 break;
984 for (i = 0; i <= smp_cpu_mtid; i++) {
985 if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i))
986 continue;
987 pcpu[i].state = CPU_STATE_STANDBY;
988 smp_cpu_set_polarization(cpu + i,
989 POLARIZATION_UNKNOWN);
990 }
991 topology_expect_change();
992 break;
993 case 1:
994 if (pcpu->state != CPU_STATE_STANDBY)
995 break;
996 rc = sclp_core_configure(pcpu->address >> smp_cpu_mt_shift);
997 if (rc)
998 break;
999 for (i = 0; i <= smp_cpu_mtid; i++) {
1000 if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i))
1001 continue;
1002 pcpu[i].state = CPU_STATE_CONFIGURED;
1003 smp_cpu_set_polarization(cpu + i,
1004 POLARIZATION_UNKNOWN);
1005 }
1006 topology_expect_change();
1007 break;
1008 default:
1009 break;
1010 }
1011out:
1012 mutex_unlock(&smp_cpu_state_mutex);
1013 put_online_cpus();
1014 return rc ? rc : count;
1015}
1016static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
1017#endif /* CONFIG_HOTPLUG_CPU */
1018
1019static ssize_t show_cpu_address(struct device *dev,
1020 struct device_attribute *attr, char *buf)
1021{
1022 return sprintf(buf, "%d\n", pcpu_devices[dev->id].address);
1023}
1024static DEVICE_ATTR(address, 0444, show_cpu_address, NULL);
1025
1026static struct attribute *cpu_common_attrs[] = {
1027#ifdef CONFIG_HOTPLUG_CPU
1028 &dev_attr_configure.attr,
1029#endif
1030 &dev_attr_address.attr,
1031 NULL,
1032};
1033
1034static struct attribute_group cpu_common_attr_group = {
1035 .attrs = cpu_common_attrs,
1036};
1037
1038static struct attribute *cpu_online_attrs[] = {
1039 &dev_attr_idle_count.attr,
1040 &dev_attr_idle_time_us.attr,
1041 NULL,
1042};
1043
1044static struct attribute_group cpu_online_attr_group = {
1045 .attrs = cpu_online_attrs,
1046};
1047
1048static int smp_cpu_online(unsigned int cpu)
1049{
1050 struct device *s = &per_cpu(cpu_device, cpu)->dev;
1051
1052 return sysfs_create_group(&s->kobj, &cpu_online_attr_group);
1053}
1054static int smp_cpu_pre_down(unsigned int cpu)
1055{
1056 struct device *s = &per_cpu(cpu_device, cpu)->dev;
1057
1058 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
1059 return 0;
1060}
1061
1062static int smp_add_present_cpu(int cpu)
1063{
1064 struct device *s;
1065 struct cpu *c;
1066 int rc;
1067
1068 c = kzalloc(sizeof(*c), GFP_KERNEL);
1069 if (!c)
1070 return -ENOMEM;
1071 per_cpu(cpu_device, cpu) = c;
1072 s = &c->dev;
1073 c->hotpluggable = 1;
1074 rc = register_cpu(c, cpu);
1075 if (rc)
1076 goto out;
1077 rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
1078 if (rc)
1079 goto out_cpu;
1080 rc = topology_cpu_init(c);
1081 if (rc)
1082 goto out_topology;
1083 return 0;
1084
1085out_topology:
1086 sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
1087out_cpu:
1088#ifdef CONFIG_HOTPLUG_CPU
1089 unregister_cpu(c);
1090#endif
1091out:
1092 return rc;
1093}
1094
1095#ifdef CONFIG_HOTPLUG_CPU
1096
1097int __ref smp_rescan_cpus(void)
1098{
1099 struct sclp_core_info *info;
1100 int nr;
1101
1102 info = kzalloc(sizeof(*info), GFP_KERNEL);
1103 if (!info)
1104 return -ENOMEM;
1105 smp_get_core_info(info, 0);
1106 get_online_cpus();
1107 mutex_lock(&smp_cpu_state_mutex);
1108 nr = __smp_rescan_cpus(info, 1);
1109 mutex_unlock(&smp_cpu_state_mutex);
1110 put_online_cpus();
1111 kfree(info);
1112 if (nr)
1113 topology_schedule_update();
1114 return 0;
1115}
1116
1117static ssize_t __ref rescan_store(struct device *dev,
1118 struct device_attribute *attr,
1119 const char *buf,
1120 size_t count)
1121{
1122 int rc;
1123
1124 rc = smp_rescan_cpus();
1125 return rc ? rc : count;
1126}
1127static DEVICE_ATTR(rescan, 0200, NULL, rescan_store);
1128#endif /* CONFIG_HOTPLUG_CPU */
1129
1130static int __init s390_smp_init(void)
1131{
1132 int cpu, rc = 0;
1133
1134#ifdef CONFIG_HOTPLUG_CPU
1135 rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan);
1136 if (rc)
1137 return rc;
1138#endif
1139 for_each_present_cpu(cpu) {
1140 rc = smp_add_present_cpu(cpu);
1141 if (rc)
1142 goto out;
1143 }
1144
1145 rc = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "s390/smp:online",
1146 smp_cpu_online, smp_cpu_pre_down);
1147out:
1148 return rc;
1149}
1150subsys_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 <linux/memblock.h>
35#include <asm/asm-offsets.h>
36#include <asm/diag.h>
37#include <asm/switch_to.h>
38#include <asm/facility.h>
39#include <asm/ipl.h>
40#include <asm/setup.h>
41#include <asm/irq.h>
42#include <asm/tlbflush.h>
43#include <asm/vtimer.h>
44#include <asm/lowcore.h>
45#include <asm/sclp.h>
46#include <asm/vdso.h>
47#include <asm/debug.h>
48#include <asm/os_info.h>
49#include <asm/sigp.h>
50#include <asm/idle.h>
51#include "entry.h"
52
53enum {
54 ec_schedule = 0,
55 ec_call_function_single,
56 ec_stop_cpu,
57};
58
59enum {
60 CPU_STATE_STANDBY,
61 CPU_STATE_CONFIGURED,
62};
63
64static DEFINE_PER_CPU(struct cpu *, cpu_device);
65
66struct pcpu {
67 struct lowcore *lowcore; /* lowcore page(s) for the cpu */
68 unsigned long ec_mask; /* bit mask for ec_xxx functions */
69 unsigned long ec_clk; /* sigp timestamp for ec_xxx */
70 signed char state; /* physical cpu state */
71 signed char polarization; /* physical polarization */
72 u16 address; /* physical cpu address */
73};
74
75static u8 boot_core_type;
76static struct pcpu pcpu_devices[NR_CPUS];
77
78unsigned int smp_cpu_mt_shift;
79EXPORT_SYMBOL(smp_cpu_mt_shift);
80
81unsigned int smp_cpu_mtid;
82EXPORT_SYMBOL(smp_cpu_mtid);
83
84#ifdef CONFIG_CRASH_DUMP
85__vector128 __initdata boot_cpu_vector_save_area[__NUM_VXRS];
86#endif
87
88static unsigned int smp_max_threads __initdata = -1U;
89
90static int __init early_nosmt(char *s)
91{
92 smp_max_threads = 1;
93 return 0;
94}
95early_param("nosmt", early_nosmt);
96
97static int __init early_smt(char *s)
98{
99 get_option(&s, &smp_max_threads);
100 return 0;
101}
102early_param("smt", early_smt);
103
104/*
105 * The smp_cpu_state_mutex must be held when changing the state or polarization
106 * member of a pcpu data structure within the pcpu_devices arreay.
107 */
108DEFINE_MUTEX(smp_cpu_state_mutex);
109
110/*
111 * Signal processor helper functions.
112 */
113static inline int __pcpu_sigp_relax(u16 addr, u8 order, unsigned long parm)
114{
115 int cc;
116
117 while (1) {
118 cc = __pcpu_sigp(addr, order, parm, NULL);
119 if (cc != SIGP_CC_BUSY)
120 return cc;
121 cpu_relax();
122 }
123}
124
125static int pcpu_sigp_retry(struct pcpu *pcpu, u8 order, u32 parm)
126{
127 int cc, retry;
128
129 for (retry = 0; ; retry++) {
130 cc = __pcpu_sigp(pcpu->address, order, parm, NULL);
131 if (cc != SIGP_CC_BUSY)
132 break;
133 if (retry >= 3)
134 udelay(10);
135 }
136 return cc;
137}
138
139static inline int pcpu_stopped(struct pcpu *pcpu)
140{
141 u32 uninitialized_var(status);
142
143 if (__pcpu_sigp(pcpu->address, SIGP_SENSE,
144 0, &status) != SIGP_CC_STATUS_STORED)
145 return 0;
146 return !!(status & (SIGP_STATUS_CHECK_STOP|SIGP_STATUS_STOPPED));
147}
148
149static inline int pcpu_running(struct pcpu *pcpu)
150{
151 if (__pcpu_sigp(pcpu->address, SIGP_SENSE_RUNNING,
152 0, NULL) != SIGP_CC_STATUS_STORED)
153 return 1;
154 /* Status stored condition code is equivalent to cpu not running. */
155 return 0;
156}
157
158/*
159 * Find struct pcpu by cpu address.
160 */
161static struct pcpu *pcpu_find_address(const struct cpumask *mask, u16 address)
162{
163 int cpu;
164
165 for_each_cpu(cpu, mask)
166 if (pcpu_devices[cpu].address == address)
167 return pcpu_devices + cpu;
168 return NULL;
169}
170
171static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit)
172{
173 int order;
174
175 if (test_and_set_bit(ec_bit, &pcpu->ec_mask))
176 return;
177 order = pcpu_running(pcpu) ? SIGP_EXTERNAL_CALL : SIGP_EMERGENCY_SIGNAL;
178 pcpu->ec_clk = get_tod_clock_fast();
179 pcpu_sigp_retry(pcpu, order, 0);
180}
181
182#define ASYNC_FRAME_OFFSET (ASYNC_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE)
183#define PANIC_FRAME_OFFSET (PAGE_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE)
184
185static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
186{
187 unsigned long async_stack, panic_stack;
188 struct lowcore *lc;
189
190 if (pcpu != &pcpu_devices[0]) {
191 pcpu->lowcore = (struct lowcore *)
192 __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
193 async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
194 panic_stack = __get_free_page(GFP_KERNEL);
195 if (!pcpu->lowcore || !panic_stack || !async_stack)
196 goto out;
197 } else {
198 async_stack = pcpu->lowcore->async_stack - ASYNC_FRAME_OFFSET;
199 panic_stack = pcpu->lowcore->panic_stack - PANIC_FRAME_OFFSET;
200 }
201 lc = pcpu->lowcore;
202 memcpy(lc, &S390_lowcore, 512);
203 memset((char *) lc + 512, 0, sizeof(*lc) - 512);
204 lc->async_stack = async_stack + ASYNC_FRAME_OFFSET;
205 lc->panic_stack = panic_stack + PANIC_FRAME_OFFSET;
206 lc->cpu_nr = cpu;
207 lc->spinlock_lockval = arch_spin_lockval(cpu);
208 if (MACHINE_HAS_VX)
209 lc->vector_save_area_addr =
210 (unsigned long) &lc->vector_save_area;
211 if (vdso_alloc_per_cpu(lc))
212 goto out;
213 lowcore_ptr[cpu] = lc;
214 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, (u32)(unsigned long) lc);
215 return 0;
216out:
217 if (pcpu != &pcpu_devices[0]) {
218 free_page(panic_stack);
219 free_pages(async_stack, ASYNC_ORDER);
220 free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
221 }
222 return -ENOMEM;
223}
224
225#ifdef CONFIG_HOTPLUG_CPU
226
227static void pcpu_free_lowcore(struct pcpu *pcpu)
228{
229 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0);
230 lowcore_ptr[pcpu - pcpu_devices] = NULL;
231 vdso_free_per_cpu(pcpu->lowcore);
232 if (pcpu == &pcpu_devices[0])
233 return;
234 free_page(pcpu->lowcore->panic_stack-PANIC_FRAME_OFFSET);
235 free_pages(pcpu->lowcore->async_stack-ASYNC_FRAME_OFFSET, ASYNC_ORDER);
236 free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
237}
238
239#endif /* CONFIG_HOTPLUG_CPU */
240
241static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu)
242{
243 struct lowcore *lc = pcpu->lowcore;
244
245 if (MACHINE_HAS_TLB_LC)
246 cpumask_set_cpu(cpu, &init_mm.context.cpu_attach_mask);
247 cpumask_set_cpu(cpu, mm_cpumask(&init_mm));
248 atomic_inc(&init_mm.context.attach_count);
249 lc->cpu_nr = cpu;
250 lc->spinlock_lockval = arch_spin_lockval(cpu);
251 lc->percpu_offset = __per_cpu_offset[cpu];
252 lc->kernel_asce = S390_lowcore.kernel_asce;
253 lc->machine_flags = S390_lowcore.machine_flags;
254 lc->user_timer = lc->system_timer = lc->steal_timer = 0;
255 __ctl_store(lc->cregs_save_area, 0, 15);
256 save_access_regs((unsigned int *) lc->access_regs_save_area);
257 memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,
258 MAX_FACILITY_BIT/8);
259}
260
261static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk)
262{
263 struct lowcore *lc = pcpu->lowcore;
264 struct thread_info *ti = task_thread_info(tsk);
265
266 lc->kernel_stack = (unsigned long) task_stack_page(tsk)
267 + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
268 lc->thread_info = (unsigned long) task_thread_info(tsk);
269 lc->current_task = (unsigned long) tsk;
270 lc->lpp = LPP_MAGIC;
271 lc->current_pid = tsk->pid;
272 lc->user_timer = ti->user_timer;
273 lc->system_timer = ti->system_timer;
274 lc->steal_timer = 0;
275}
276
277static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data)
278{
279 struct lowcore *lc = pcpu->lowcore;
280
281 lc->restart_stack = lc->kernel_stack;
282 lc->restart_fn = (unsigned long) func;
283 lc->restart_data = (unsigned long) data;
284 lc->restart_source = -1UL;
285 pcpu_sigp_retry(pcpu, SIGP_RESTART, 0);
286}
287
288/*
289 * Call function via PSW restart on pcpu and stop the current cpu.
290 */
291static void pcpu_delegate(struct pcpu *pcpu, void (*func)(void *),
292 void *data, unsigned long stack)
293{
294 struct lowcore *lc = lowcore_ptr[pcpu - pcpu_devices];
295 unsigned long source_cpu = stap();
296
297 __load_psw_mask(PSW_KERNEL_BITS);
298 if (pcpu->address == source_cpu)
299 func(data); /* should not return */
300 /* Stop target cpu (if func returns this stops the current cpu). */
301 pcpu_sigp_retry(pcpu, SIGP_STOP, 0);
302 /* Restart func on the target cpu and stop the current cpu. */
303 mem_assign_absolute(lc->restart_stack, stack);
304 mem_assign_absolute(lc->restart_fn, (unsigned long) func);
305 mem_assign_absolute(lc->restart_data, (unsigned long) data);
306 mem_assign_absolute(lc->restart_source, source_cpu);
307 asm volatile(
308 "0: sigp 0,%0,%2 # sigp restart to target cpu\n"
309 " brc 2,0b # busy, try again\n"
310 "1: sigp 0,%1,%3 # sigp stop to current cpu\n"
311 " brc 2,1b # busy, try again\n"
312 : : "d" (pcpu->address), "d" (source_cpu),
313 "K" (SIGP_RESTART), "K" (SIGP_STOP)
314 : "0", "1", "cc");
315 for (;;) ;
316}
317
318/*
319 * Enable additional logical cpus for multi-threading.
320 */
321static int pcpu_set_smt(unsigned int mtid)
322{
323 register unsigned long reg1 asm ("1") = (unsigned long) mtid;
324 int cc;
325
326 if (smp_cpu_mtid == mtid)
327 return 0;
328 asm volatile(
329 " sigp %1,0,%2 # sigp set multi-threading\n"
330 " ipm %0\n"
331 " srl %0,28\n"
332 : "=d" (cc) : "d" (reg1), "K" (SIGP_SET_MULTI_THREADING)
333 : "cc");
334 if (cc == 0) {
335 smp_cpu_mtid = mtid;
336 smp_cpu_mt_shift = 0;
337 while (smp_cpu_mtid >= (1U << smp_cpu_mt_shift))
338 smp_cpu_mt_shift++;
339 pcpu_devices[0].address = stap();
340 }
341 return cc;
342}
343
344/*
345 * Call function on an online CPU.
346 */
347void smp_call_online_cpu(void (*func)(void *), void *data)
348{
349 struct pcpu *pcpu;
350
351 /* Use the current cpu if it is online. */
352 pcpu = pcpu_find_address(cpu_online_mask, stap());
353 if (!pcpu)
354 /* Use the first online cpu. */
355 pcpu = pcpu_devices + cpumask_first(cpu_online_mask);
356 pcpu_delegate(pcpu, func, data, (unsigned long) restart_stack);
357}
358
359/*
360 * Call function on the ipl CPU.
361 */
362void smp_call_ipl_cpu(void (*func)(void *), void *data)
363{
364 pcpu_delegate(&pcpu_devices[0], func, data,
365 pcpu_devices->lowcore->panic_stack -
366 PANIC_FRAME_OFFSET + PAGE_SIZE);
367}
368
369int smp_find_processor_id(u16 address)
370{
371 int cpu;
372
373 for_each_present_cpu(cpu)
374 if (pcpu_devices[cpu].address == address)
375 return cpu;
376 return -1;
377}
378
379int smp_vcpu_scheduled(int cpu)
380{
381 return pcpu_running(pcpu_devices + cpu);
382}
383
384void smp_yield_cpu(int cpu)
385{
386 if (MACHINE_HAS_DIAG9C) {
387 diag_stat_inc_norecursion(DIAG_STAT_X09C);
388 asm volatile("diag %0,0,0x9c"
389 : : "d" (pcpu_devices[cpu].address));
390 } else if (MACHINE_HAS_DIAG44) {
391 diag_stat_inc_norecursion(DIAG_STAT_X044);
392 asm volatile("diag 0,0,0x44");
393 }
394}
395
396/*
397 * Send cpus emergency shutdown signal. This gives the cpus the
398 * opportunity to complete outstanding interrupts.
399 */
400static void smp_emergency_stop(cpumask_t *cpumask)
401{
402 u64 end;
403 int cpu;
404
405 end = get_tod_clock() + (1000000UL << 12);
406 for_each_cpu(cpu, cpumask) {
407 struct pcpu *pcpu = pcpu_devices + cpu;
408 set_bit(ec_stop_cpu, &pcpu->ec_mask);
409 while (__pcpu_sigp(pcpu->address, SIGP_EMERGENCY_SIGNAL,
410 0, NULL) == SIGP_CC_BUSY &&
411 get_tod_clock() < end)
412 cpu_relax();
413 }
414 while (get_tod_clock() < end) {
415 for_each_cpu(cpu, cpumask)
416 if (pcpu_stopped(pcpu_devices + cpu))
417 cpumask_clear_cpu(cpu, cpumask);
418 if (cpumask_empty(cpumask))
419 break;
420 cpu_relax();
421 }
422}
423
424/*
425 * Stop all cpus but the current one.
426 */
427void smp_send_stop(void)
428{
429 cpumask_t cpumask;
430 int cpu;
431
432 /* Disable all interrupts/machine checks */
433 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
434 trace_hardirqs_off();
435
436 debug_set_critical();
437 cpumask_copy(&cpumask, cpu_online_mask);
438 cpumask_clear_cpu(smp_processor_id(), &cpumask);
439
440 if (oops_in_progress)
441 smp_emergency_stop(&cpumask);
442
443 /* stop all processors */
444 for_each_cpu(cpu, &cpumask) {
445 struct pcpu *pcpu = pcpu_devices + cpu;
446 pcpu_sigp_retry(pcpu, SIGP_STOP, 0);
447 while (!pcpu_stopped(pcpu))
448 cpu_relax();
449 }
450}
451
452/*
453 * This is the main routine where commands issued by other
454 * cpus are handled.
455 */
456static void smp_handle_ext_call(void)
457{
458 unsigned long bits;
459
460 /* handle bit signal external calls */
461 bits = xchg(&pcpu_devices[smp_processor_id()].ec_mask, 0);
462 if (test_bit(ec_stop_cpu, &bits))
463 smp_stop_cpu();
464 if (test_bit(ec_schedule, &bits))
465 scheduler_ipi();
466 if (test_bit(ec_call_function_single, &bits))
467 generic_smp_call_function_single_interrupt();
468}
469
470static void do_ext_call_interrupt(struct ext_code ext_code,
471 unsigned int param32, unsigned long param64)
472{
473 inc_irq_stat(ext_code.code == 0x1202 ? IRQEXT_EXC : IRQEXT_EMS);
474 smp_handle_ext_call();
475}
476
477void arch_send_call_function_ipi_mask(const struct cpumask *mask)
478{
479 int cpu;
480
481 for_each_cpu(cpu, mask)
482 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
483}
484
485void arch_send_call_function_single_ipi(int cpu)
486{
487 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
488}
489
490/*
491 * this function sends a 'reschedule' IPI to another CPU.
492 * it goes straight through and wastes no time serializing
493 * anything. Worst case is that we lose a reschedule ...
494 */
495void smp_send_reschedule(int cpu)
496{
497 pcpu_ec_call(pcpu_devices + cpu, ec_schedule);
498}
499
500/*
501 * parameter area for the set/clear control bit callbacks
502 */
503struct ec_creg_mask_parms {
504 unsigned long orval;
505 unsigned long andval;
506 int cr;
507};
508
509/*
510 * callback for setting/clearing control bits
511 */
512static void smp_ctl_bit_callback(void *info)
513{
514 struct ec_creg_mask_parms *pp = info;
515 unsigned long cregs[16];
516
517 __ctl_store(cregs, 0, 15);
518 cregs[pp->cr] = (cregs[pp->cr] & pp->andval) | pp->orval;
519 __ctl_load(cregs, 0, 15);
520}
521
522/*
523 * Set a bit in a control register of all cpus
524 */
525void smp_ctl_set_bit(int cr, int bit)
526{
527 struct ec_creg_mask_parms parms = { 1UL << bit, -1UL, cr };
528
529 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
530}
531EXPORT_SYMBOL(smp_ctl_set_bit);
532
533/*
534 * Clear a bit in a control register of all cpus
535 */
536void smp_ctl_clear_bit(int cr, int bit)
537{
538 struct ec_creg_mask_parms parms = { 0, ~(1UL << bit), cr };
539
540 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
541}
542EXPORT_SYMBOL(smp_ctl_clear_bit);
543
544#ifdef CONFIG_CRASH_DUMP
545
546int smp_store_status(int cpu)
547{
548 struct pcpu *pcpu = pcpu_devices + cpu;
549 unsigned long pa;
550
551 pa = __pa(&pcpu->lowcore->floating_pt_save_area);
552 if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_STATUS_AT_ADDRESS,
553 pa) != SIGP_CC_ORDER_CODE_ACCEPTED)
554 return -EIO;
555 if (!MACHINE_HAS_VX)
556 return 0;
557 pa = __pa(pcpu->lowcore->vector_save_area_addr);
558 if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_ADDITIONAL_STATUS,
559 pa) != SIGP_CC_ORDER_CODE_ACCEPTED)
560 return -EIO;
561 return 0;
562}
563
564/*
565 * Collect CPU state of the previous, crashed system.
566 * There are four cases:
567 * 1) standard zfcp dump
568 * condition: OLDMEM_BASE == NULL && ipl_info.type == IPL_TYPE_FCP_DUMP
569 * The state for all CPUs except the boot CPU needs to be collected
570 * with sigp stop-and-store-status. The boot CPU state is located in
571 * the absolute lowcore of the memory stored in the HSA. The zcore code
572 * will copy the boot CPU state from the HSA.
573 * 2) stand-alone kdump for SCSI (zfcp dump with swapped memory)
574 * condition: OLDMEM_BASE != NULL && ipl_info.type == IPL_TYPE_FCP_DUMP
575 * The state for all CPUs except the boot CPU needs to be collected
576 * with sigp stop-and-store-status. The firmware or the boot-loader
577 * stored the registers of the boot CPU in the absolute lowcore in the
578 * memory of the old system.
579 * 3) kdump and the old kernel did not store the CPU state,
580 * or stand-alone kdump for DASD
581 * condition: OLDMEM_BASE != NULL && !is_kdump_kernel()
582 * The state for all CPUs except the boot CPU needs to be collected
583 * with sigp stop-and-store-status. The kexec code or the boot-loader
584 * stored the registers of the boot CPU in the memory of the old system.
585 * 4) kdump and the old kernel stored the CPU state
586 * condition: OLDMEM_BASE != NULL && is_kdump_kernel()
587 * This case does not exist for s390 anymore, setup_arch explicitly
588 * deactivates the elfcorehdr= kernel parameter
589 */
590static __init void smp_save_cpu_vxrs(struct save_area *sa, u16 addr,
591 bool is_boot_cpu, unsigned long page)
592{
593 __vector128 *vxrs = (__vector128 *) page;
594
595 if (is_boot_cpu)
596 vxrs = boot_cpu_vector_save_area;
597 else
598 __pcpu_sigp_relax(addr, SIGP_STORE_ADDITIONAL_STATUS, page);
599 save_area_add_vxrs(sa, vxrs);
600}
601
602static __init void smp_save_cpu_regs(struct save_area *sa, u16 addr,
603 bool is_boot_cpu, unsigned long page)
604{
605 void *regs = (void *) page;
606
607 if (is_boot_cpu)
608 copy_oldmem_kernel(regs, (void *) __LC_FPREGS_SAVE_AREA, 512);
609 else
610 __pcpu_sigp_relax(addr, SIGP_STORE_STATUS_AT_ADDRESS, page);
611 save_area_add_regs(sa, regs);
612}
613
614void __init smp_save_dump_cpus(void)
615{
616 int addr, boot_cpu_addr, max_cpu_addr;
617 struct save_area *sa;
618 unsigned long page;
619 bool is_boot_cpu;
620
621 if (!(OLDMEM_BASE || ipl_info.type == IPL_TYPE_FCP_DUMP))
622 /* No previous system present, normal boot. */
623 return;
624 /* Allocate a page as dumping area for the store status sigps */
625 page = memblock_alloc_base(PAGE_SIZE, PAGE_SIZE, 1UL << 31);
626 /* Set multi-threading state to the previous system. */
627 pcpu_set_smt(sclp.mtid_prev);
628 boot_cpu_addr = stap();
629 max_cpu_addr = SCLP_MAX_CORES << sclp.mtid_prev;
630 for (addr = 0; addr <= max_cpu_addr; addr++) {
631 if (__pcpu_sigp_relax(addr, SIGP_SENSE, 0) ==
632 SIGP_CC_NOT_OPERATIONAL)
633 continue;
634 is_boot_cpu = (addr == boot_cpu_addr);
635 /* Allocate save area */
636 sa = save_area_alloc(is_boot_cpu);
637 if (!sa)
638 panic("could not allocate memory for save area\n");
639 if (MACHINE_HAS_VX)
640 /* Get the vector registers */
641 smp_save_cpu_vxrs(sa, addr, is_boot_cpu, page);
642 /*
643 * For a zfcp dump OLDMEM_BASE == NULL and the registers
644 * of the boot CPU are stored in the HSA. To retrieve
645 * these registers an SCLP request is required which is
646 * done by drivers/s390/char/zcore.c:init_cpu_info()
647 */
648 if (!is_boot_cpu || OLDMEM_BASE)
649 /* Get the CPU registers */
650 smp_save_cpu_regs(sa, addr, is_boot_cpu, page);
651 }
652 memblock_free(page, PAGE_SIZE);
653 diag308_reset();
654 pcpu_set_smt(0);
655}
656#endif /* CONFIG_CRASH_DUMP */
657
658void smp_cpu_set_polarization(int cpu, int val)
659{
660 pcpu_devices[cpu].polarization = val;
661}
662
663int smp_cpu_get_polarization(int cpu)
664{
665 return pcpu_devices[cpu].polarization;
666}
667
668static struct sclp_core_info *smp_get_core_info(void)
669{
670 static int use_sigp_detection;
671 struct sclp_core_info *info;
672 int address;
673
674 info = kzalloc(sizeof(*info), GFP_KERNEL);
675 if (info && (use_sigp_detection || sclp_get_core_info(info))) {
676 use_sigp_detection = 1;
677 for (address = 0;
678 address < (SCLP_MAX_CORES << smp_cpu_mt_shift);
679 address += (1U << smp_cpu_mt_shift)) {
680 if (__pcpu_sigp_relax(address, SIGP_SENSE, 0) ==
681 SIGP_CC_NOT_OPERATIONAL)
682 continue;
683 info->core[info->configured].core_id =
684 address >> smp_cpu_mt_shift;
685 info->configured++;
686 }
687 info->combined = info->configured;
688 }
689 return info;
690}
691
692static int smp_add_present_cpu(int cpu);
693
694static int __smp_rescan_cpus(struct sclp_core_info *info, int sysfs_add)
695{
696 struct pcpu *pcpu;
697 cpumask_t avail;
698 int cpu, nr, i, j;
699 u16 address;
700
701 nr = 0;
702 cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask);
703 cpu = cpumask_first(&avail);
704 for (i = 0; (i < info->combined) && (cpu < nr_cpu_ids); i++) {
705 if (sclp.has_core_type && info->core[i].type != boot_core_type)
706 continue;
707 address = info->core[i].core_id << smp_cpu_mt_shift;
708 for (j = 0; j <= smp_cpu_mtid; j++) {
709 if (pcpu_find_address(cpu_present_mask, address + j))
710 continue;
711 pcpu = pcpu_devices + cpu;
712 pcpu->address = address + j;
713 pcpu->state =
714 (cpu >= info->configured*(smp_cpu_mtid + 1)) ?
715 CPU_STATE_STANDBY : CPU_STATE_CONFIGURED;
716 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
717 set_cpu_present(cpu, true);
718 if (sysfs_add && smp_add_present_cpu(cpu) != 0)
719 set_cpu_present(cpu, false);
720 else
721 nr++;
722 cpu = cpumask_next(cpu, &avail);
723 if (cpu >= nr_cpu_ids)
724 break;
725 }
726 }
727 return nr;
728}
729
730static void __init smp_detect_cpus(void)
731{
732 unsigned int cpu, mtid, c_cpus, s_cpus;
733 struct sclp_core_info *info;
734 u16 address;
735
736 /* Get CPU information */
737 info = smp_get_core_info();
738 if (!info)
739 panic("smp_detect_cpus failed to allocate memory\n");
740
741 /* Find boot CPU type */
742 if (sclp.has_core_type) {
743 address = stap();
744 for (cpu = 0; cpu < info->combined; cpu++)
745 if (info->core[cpu].core_id == address) {
746 /* The boot cpu dictates the cpu type. */
747 boot_core_type = info->core[cpu].type;
748 break;
749 }
750 if (cpu >= info->combined)
751 panic("Could not find boot CPU type");
752 }
753
754 /* Set multi-threading state for the current system */
755 mtid = boot_core_type ? sclp.mtid : sclp.mtid_cp;
756 mtid = (mtid < smp_max_threads) ? mtid : smp_max_threads - 1;
757 pcpu_set_smt(mtid);
758
759 /* Print number of CPUs */
760 c_cpus = s_cpus = 0;
761 for (cpu = 0; cpu < info->combined; cpu++) {
762 if (sclp.has_core_type &&
763 info->core[cpu].type != boot_core_type)
764 continue;
765 if (cpu < info->configured)
766 c_cpus += smp_cpu_mtid + 1;
767 else
768 s_cpus += smp_cpu_mtid + 1;
769 }
770 pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
771
772 /* Add CPUs present at boot */
773 get_online_cpus();
774 __smp_rescan_cpus(info, 0);
775 put_online_cpus();
776 kfree(info);
777}
778
779/*
780 * Activate a secondary processor.
781 */
782static void smp_start_secondary(void *cpuvoid)
783{
784 S390_lowcore.last_update_clock = get_tod_clock();
785 S390_lowcore.restart_stack = (unsigned long) restart_stack;
786 S390_lowcore.restart_fn = (unsigned long) do_restart;
787 S390_lowcore.restart_data = 0;
788 S390_lowcore.restart_source = -1UL;
789 restore_access_regs(S390_lowcore.access_regs_save_area);
790 __ctl_load(S390_lowcore.cregs_save_area, 0, 15);
791 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
792 cpu_init();
793 preempt_disable();
794 init_cpu_timer();
795 vtime_init();
796 pfault_init();
797 notify_cpu_starting(smp_processor_id());
798 set_cpu_online(smp_processor_id(), true);
799 inc_irq_stat(CPU_RST);
800 local_irq_enable();
801 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
802}
803
804/* Upping and downing of CPUs */
805int __cpu_up(unsigned int cpu, struct task_struct *tidle)
806{
807 struct pcpu *pcpu;
808 int base, i, rc;
809
810 pcpu = pcpu_devices + cpu;
811 if (pcpu->state != CPU_STATE_CONFIGURED)
812 return -EIO;
813 base = cpu - (cpu % (smp_cpu_mtid + 1));
814 for (i = 0; i <= smp_cpu_mtid; i++) {
815 if (base + i < nr_cpu_ids)
816 if (cpu_online(base + i))
817 break;
818 }
819 /*
820 * If this is the first CPU of the core to get online
821 * do an initial CPU reset.
822 */
823 if (i > smp_cpu_mtid &&
824 pcpu_sigp_retry(pcpu_devices + base, SIGP_INITIAL_CPU_RESET, 0) !=
825 SIGP_CC_ORDER_CODE_ACCEPTED)
826 return -EIO;
827
828 rc = pcpu_alloc_lowcore(pcpu, cpu);
829 if (rc)
830 return rc;
831 pcpu_prepare_secondary(pcpu, cpu);
832 pcpu_attach_task(pcpu, tidle);
833 pcpu_start_fn(pcpu, smp_start_secondary, NULL);
834 /* Wait until cpu puts itself in the online & active maps */
835 while (!cpu_online(cpu) || !cpu_active(cpu))
836 cpu_relax();
837 return 0;
838}
839
840static unsigned int setup_possible_cpus __initdata;
841
842static int __init _setup_possible_cpus(char *s)
843{
844 get_option(&s, &setup_possible_cpus);
845 return 0;
846}
847early_param("possible_cpus", _setup_possible_cpus);
848
849#ifdef CONFIG_HOTPLUG_CPU
850
851int __cpu_disable(void)
852{
853 unsigned long cregs[16];
854
855 /* Handle possible pending IPIs */
856 smp_handle_ext_call();
857 set_cpu_online(smp_processor_id(), false);
858 /* Disable pseudo page faults on this cpu. */
859 pfault_fini();
860 /* Disable interrupt sources via control register. */
861 __ctl_store(cregs, 0, 15);
862 cregs[0] &= ~0x0000ee70UL; /* disable all external interrupts */
863 cregs[6] &= ~0xff000000UL; /* disable all I/O interrupts */
864 cregs[14] &= ~0x1f000000UL; /* disable most machine checks */
865 __ctl_load(cregs, 0, 15);
866 clear_cpu_flag(CIF_NOHZ_DELAY);
867 return 0;
868}
869
870void __cpu_die(unsigned int cpu)
871{
872 struct pcpu *pcpu;
873
874 /* Wait until target cpu is down */
875 pcpu = pcpu_devices + cpu;
876 while (!pcpu_stopped(pcpu))
877 cpu_relax();
878 pcpu_free_lowcore(pcpu);
879 atomic_dec(&init_mm.context.attach_count);
880 cpumask_clear_cpu(cpu, mm_cpumask(&init_mm));
881 if (MACHINE_HAS_TLB_LC)
882 cpumask_clear_cpu(cpu, &init_mm.context.cpu_attach_mask);
883}
884
885void __noreturn cpu_die(void)
886{
887 idle_task_exit();
888 pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0);
889 for (;;) ;
890}
891
892#endif /* CONFIG_HOTPLUG_CPU */
893
894void __init smp_fill_possible_mask(void)
895{
896 unsigned int possible, sclp_max, cpu;
897
898 sclp_max = max(sclp.mtid, sclp.mtid_cp) + 1;
899 sclp_max = min(smp_max_threads, sclp_max);
900 sclp_max = sclp.max_cores * sclp_max ?: nr_cpu_ids;
901 possible = setup_possible_cpus ?: nr_cpu_ids;
902 possible = min(possible, sclp_max);
903 for (cpu = 0; cpu < possible && cpu < nr_cpu_ids; cpu++)
904 set_cpu_possible(cpu, true);
905}
906
907void __init smp_prepare_cpus(unsigned int max_cpus)
908{
909 /* request the 0x1201 emergency signal external interrupt */
910 if (register_external_irq(EXT_IRQ_EMERGENCY_SIG, do_ext_call_interrupt))
911 panic("Couldn't request external interrupt 0x1201");
912 /* request the 0x1202 external call external interrupt */
913 if (register_external_irq(EXT_IRQ_EXTERNAL_CALL, do_ext_call_interrupt))
914 panic("Couldn't request external interrupt 0x1202");
915 smp_detect_cpus();
916}
917
918void __init smp_prepare_boot_cpu(void)
919{
920 struct pcpu *pcpu = pcpu_devices;
921
922 pcpu->state = CPU_STATE_CONFIGURED;
923 pcpu->address = stap();
924 pcpu->lowcore = (struct lowcore *)(unsigned long) store_prefix();
925 S390_lowcore.percpu_offset = __per_cpu_offset[0];
926 smp_cpu_set_polarization(0, POLARIZATION_UNKNOWN);
927 set_cpu_present(0, true);
928 set_cpu_online(0, true);
929}
930
931void __init smp_cpus_done(unsigned int max_cpus)
932{
933}
934
935void __init smp_setup_processor_id(void)
936{
937 S390_lowcore.cpu_nr = 0;
938 S390_lowcore.spinlock_lockval = arch_spin_lockval(0);
939}
940
941/*
942 * the frequency of the profiling timer can be changed
943 * by writing a multiplier value into /proc/profile.
944 *
945 * usually you want to run this on all CPUs ;)
946 */
947int setup_profiling_timer(unsigned int multiplier)
948{
949 return 0;
950}
951
952#ifdef CONFIG_HOTPLUG_CPU
953static ssize_t cpu_configure_show(struct device *dev,
954 struct device_attribute *attr, char *buf)
955{
956 ssize_t count;
957
958 mutex_lock(&smp_cpu_state_mutex);
959 count = sprintf(buf, "%d\n", pcpu_devices[dev->id].state);
960 mutex_unlock(&smp_cpu_state_mutex);
961 return count;
962}
963
964static ssize_t cpu_configure_store(struct device *dev,
965 struct device_attribute *attr,
966 const char *buf, size_t count)
967{
968 struct pcpu *pcpu;
969 int cpu, val, rc, i;
970 char delim;
971
972 if (sscanf(buf, "%d %c", &val, &delim) != 1)
973 return -EINVAL;
974 if (val != 0 && val != 1)
975 return -EINVAL;
976 get_online_cpus();
977 mutex_lock(&smp_cpu_state_mutex);
978 rc = -EBUSY;
979 /* disallow configuration changes of online cpus and cpu 0 */
980 cpu = dev->id;
981 cpu -= cpu % (smp_cpu_mtid + 1);
982 if (cpu == 0)
983 goto out;
984 for (i = 0; i <= smp_cpu_mtid; i++)
985 if (cpu_online(cpu + i))
986 goto out;
987 pcpu = pcpu_devices + cpu;
988 rc = 0;
989 switch (val) {
990 case 0:
991 if (pcpu->state != CPU_STATE_CONFIGURED)
992 break;
993 rc = sclp_core_deconfigure(pcpu->address >> smp_cpu_mt_shift);
994 if (rc)
995 break;
996 for (i = 0; i <= smp_cpu_mtid; i++) {
997 if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i))
998 continue;
999 pcpu[i].state = CPU_STATE_STANDBY;
1000 smp_cpu_set_polarization(cpu + i,
1001 POLARIZATION_UNKNOWN);
1002 }
1003 topology_expect_change();
1004 break;
1005 case 1:
1006 if (pcpu->state != CPU_STATE_STANDBY)
1007 break;
1008 rc = sclp_core_configure(pcpu->address >> smp_cpu_mt_shift);
1009 if (rc)
1010 break;
1011 for (i = 0; i <= smp_cpu_mtid; i++) {
1012 if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i))
1013 continue;
1014 pcpu[i].state = CPU_STATE_CONFIGURED;
1015 smp_cpu_set_polarization(cpu + i,
1016 POLARIZATION_UNKNOWN);
1017 }
1018 topology_expect_change();
1019 break;
1020 default:
1021 break;
1022 }
1023out:
1024 mutex_unlock(&smp_cpu_state_mutex);
1025 put_online_cpus();
1026 return rc ? rc : count;
1027}
1028static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
1029#endif /* CONFIG_HOTPLUG_CPU */
1030
1031static ssize_t show_cpu_address(struct device *dev,
1032 struct device_attribute *attr, char *buf)
1033{
1034 return sprintf(buf, "%d\n", pcpu_devices[dev->id].address);
1035}
1036static DEVICE_ATTR(address, 0444, show_cpu_address, NULL);
1037
1038static struct attribute *cpu_common_attrs[] = {
1039#ifdef CONFIG_HOTPLUG_CPU
1040 &dev_attr_configure.attr,
1041#endif
1042 &dev_attr_address.attr,
1043 NULL,
1044};
1045
1046static struct attribute_group cpu_common_attr_group = {
1047 .attrs = cpu_common_attrs,
1048};
1049
1050static struct attribute *cpu_online_attrs[] = {
1051 &dev_attr_idle_count.attr,
1052 &dev_attr_idle_time_us.attr,
1053 NULL,
1054};
1055
1056static struct attribute_group cpu_online_attr_group = {
1057 .attrs = cpu_online_attrs,
1058};
1059
1060static int smp_cpu_notify(struct notifier_block *self, unsigned long action,
1061 void *hcpu)
1062{
1063 unsigned int cpu = (unsigned int)(long)hcpu;
1064 struct device *s = &per_cpu(cpu_device, cpu)->dev;
1065 int err = 0;
1066
1067 switch (action & ~CPU_TASKS_FROZEN) {
1068 case CPU_ONLINE:
1069 err = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
1070 break;
1071 case CPU_DEAD:
1072 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
1073 break;
1074 }
1075 return notifier_from_errno(err);
1076}
1077
1078static int smp_add_present_cpu(int cpu)
1079{
1080 struct device *s;
1081 struct cpu *c;
1082 int rc;
1083
1084 c = kzalloc(sizeof(*c), GFP_KERNEL);
1085 if (!c)
1086 return -ENOMEM;
1087 per_cpu(cpu_device, cpu) = c;
1088 s = &c->dev;
1089 c->hotpluggable = 1;
1090 rc = register_cpu(c, cpu);
1091 if (rc)
1092 goto out;
1093 rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
1094 if (rc)
1095 goto out_cpu;
1096 if (cpu_online(cpu)) {
1097 rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
1098 if (rc)
1099 goto out_online;
1100 }
1101 rc = topology_cpu_init(c);
1102 if (rc)
1103 goto out_topology;
1104 return 0;
1105
1106out_topology:
1107 if (cpu_online(cpu))
1108 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
1109out_online:
1110 sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
1111out_cpu:
1112#ifdef CONFIG_HOTPLUG_CPU
1113 unregister_cpu(c);
1114#endif
1115out:
1116 return rc;
1117}
1118
1119#ifdef CONFIG_HOTPLUG_CPU
1120
1121int __ref smp_rescan_cpus(void)
1122{
1123 struct sclp_core_info *info;
1124 int nr;
1125
1126 info = smp_get_core_info();
1127 if (!info)
1128 return -ENOMEM;
1129 get_online_cpus();
1130 mutex_lock(&smp_cpu_state_mutex);
1131 nr = __smp_rescan_cpus(info, 1);
1132 mutex_unlock(&smp_cpu_state_mutex);
1133 put_online_cpus();
1134 kfree(info);
1135 if (nr)
1136 topology_schedule_update();
1137 return 0;
1138}
1139
1140static ssize_t __ref rescan_store(struct device *dev,
1141 struct device_attribute *attr,
1142 const char *buf,
1143 size_t count)
1144{
1145 int rc;
1146
1147 rc = smp_rescan_cpus();
1148 return rc ? rc : count;
1149}
1150static DEVICE_ATTR(rescan, 0200, NULL, rescan_store);
1151#endif /* CONFIG_HOTPLUG_CPU */
1152
1153static int __init s390_smp_init(void)
1154{
1155 int cpu, rc = 0;
1156
1157#ifdef CONFIG_HOTPLUG_CPU
1158 rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan);
1159 if (rc)
1160 return rc;
1161#endif
1162 cpu_notifier_register_begin();
1163 for_each_present_cpu(cpu) {
1164 rc = smp_add_present_cpu(cpu);
1165 if (rc)
1166 goto out;
1167 }
1168
1169 __hotcpu_notifier(smp_cpu_notify, 0);
1170
1171out:
1172 cpu_notifier_register_done();
1173 return rc;
1174}
1175subsys_initcall(s390_smp_init);