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