Merge tag 'pm+acpi-4.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael...
[linux/fpc-iii.git] / arch / s390 / kernel / smp.c
blob6f54c175f5c9012b5cc00f28d3d793c2bfc56ec5
1 /*
2 * SMP related functions
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>,
9 * based on other smp stuff by
10 * (c) 1995 Alan Cox, CymruNET Ltd <alan@cymru.net>
11 * (c) 1998 Ingo Molnar
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.
18 #define KMSG_COMPONENT "cpu"
19 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
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/switch_to.h>
37 #include <asm/facility.h>
38 #include <asm/ipl.h>
39 #include <asm/setup.h>
40 #include <asm/irq.h>
41 #include <asm/tlbflush.h>
42 #include <asm/vtimer.h>
43 #include <asm/lowcore.h>
44 #include <asm/sclp.h>
45 #include <asm/vdso.h>
46 #include <asm/debug.h>
47 #include <asm/os_info.h>
48 #include <asm/sigp.h>
49 #include <asm/idle.h>
50 #include "entry.h"
52 enum {
53 ec_schedule = 0,
54 ec_call_function_single,
55 ec_stop_cpu,
58 enum {
59 CPU_STATE_STANDBY,
60 CPU_STATE_CONFIGURED,
63 static DEFINE_PER_CPU(struct cpu *, cpu_device);
65 struct pcpu {
66 struct _lowcore *lowcore; /* lowcore page(s) for the cpu */
67 unsigned long ec_mask; /* bit mask for ec_xxx functions */
68 signed char state; /* physical cpu state */
69 signed char polarization; /* physical polarization */
70 u16 address; /* physical cpu address */
73 static u8 boot_core_type;
74 static struct pcpu pcpu_devices[NR_CPUS];
76 unsigned int smp_cpu_mt_shift;
77 EXPORT_SYMBOL(smp_cpu_mt_shift);
79 unsigned int smp_cpu_mtid;
80 EXPORT_SYMBOL(smp_cpu_mtid);
82 static unsigned int smp_max_threads __initdata = -1U;
84 static int __init early_nosmt(char *s)
86 smp_max_threads = 1;
87 return 0;
89 early_param("nosmt", early_nosmt);
91 static int __init early_smt(char *s)
93 get_option(&s, &smp_max_threads);
94 return 0;
96 early_param("smt", early_smt);
99 * The smp_cpu_state_mutex must be held when changing the state or polarization
100 * member of a pcpu data structure within the pcpu_devices arreay.
102 DEFINE_MUTEX(smp_cpu_state_mutex);
105 * Signal processor helper functions.
107 static inline int __pcpu_sigp_relax(u16 addr, u8 order, unsigned long parm,
108 u32 *status)
110 int cc;
112 while (1) {
113 cc = __pcpu_sigp(addr, order, parm, NULL);
114 if (cc != SIGP_CC_BUSY)
115 return cc;
116 cpu_relax();
120 static int pcpu_sigp_retry(struct pcpu *pcpu, u8 order, u32 parm)
122 int cc, retry;
124 for (retry = 0; ; retry++) {
125 cc = __pcpu_sigp(pcpu->address, order, parm, NULL);
126 if (cc != SIGP_CC_BUSY)
127 break;
128 if (retry >= 3)
129 udelay(10);
131 return cc;
134 static inline int pcpu_stopped(struct pcpu *pcpu)
136 u32 uninitialized_var(status);
138 if (__pcpu_sigp(pcpu->address, SIGP_SENSE,
139 0, &status) != SIGP_CC_STATUS_STORED)
140 return 0;
141 return !!(status & (SIGP_STATUS_CHECK_STOP|SIGP_STATUS_STOPPED));
144 static inline int pcpu_running(struct pcpu *pcpu)
146 if (__pcpu_sigp(pcpu->address, SIGP_SENSE_RUNNING,
147 0, NULL) != SIGP_CC_STATUS_STORED)
148 return 1;
149 /* Status stored condition code is equivalent to cpu not running. */
150 return 0;
154 * Find struct pcpu by cpu address.
156 static struct pcpu *pcpu_find_address(const struct cpumask *mask, u16 address)
158 int cpu;
160 for_each_cpu(cpu, mask)
161 if (pcpu_devices[cpu].address == address)
162 return pcpu_devices + cpu;
163 return NULL;
166 static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit)
168 int order;
170 if (test_and_set_bit(ec_bit, &pcpu->ec_mask))
171 return;
172 order = pcpu_running(pcpu) ? SIGP_EXTERNAL_CALL : SIGP_EMERGENCY_SIGNAL;
173 pcpu_sigp_retry(pcpu, order, 0);
176 #define ASYNC_FRAME_OFFSET (ASYNC_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE)
177 #define PANIC_FRAME_OFFSET (PAGE_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE)
179 static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
181 unsigned long async_stack, panic_stack;
182 struct _lowcore *lc;
184 if (pcpu != &pcpu_devices[0]) {
185 pcpu->lowcore = (struct _lowcore *)
186 __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
187 async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
188 panic_stack = __get_free_page(GFP_KERNEL);
189 if (!pcpu->lowcore || !panic_stack || !async_stack)
190 goto out;
191 } else {
192 async_stack = pcpu->lowcore->async_stack - ASYNC_FRAME_OFFSET;
193 panic_stack = pcpu->lowcore->panic_stack - PANIC_FRAME_OFFSET;
195 lc = pcpu->lowcore;
196 memcpy(lc, &S390_lowcore, 512);
197 memset((char *) lc + 512, 0, sizeof(*lc) - 512);
198 lc->async_stack = async_stack + ASYNC_FRAME_OFFSET;
199 lc->panic_stack = panic_stack + PANIC_FRAME_OFFSET;
200 lc->cpu_nr = cpu;
201 lc->spinlock_lockval = arch_spin_lockval(cpu);
202 if (MACHINE_HAS_VX)
203 lc->vector_save_area_addr =
204 (unsigned long) &lc->vector_save_area;
205 if (vdso_alloc_per_cpu(lc))
206 goto out;
207 lowcore_ptr[cpu] = lc;
208 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, (u32)(unsigned long) lc);
209 return 0;
210 out:
211 if (pcpu != &pcpu_devices[0]) {
212 free_page(panic_stack);
213 free_pages(async_stack, ASYNC_ORDER);
214 free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
216 return -ENOMEM;
219 #ifdef CONFIG_HOTPLUG_CPU
221 static void pcpu_free_lowcore(struct pcpu *pcpu)
223 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0);
224 lowcore_ptr[pcpu - pcpu_devices] = NULL;
225 vdso_free_per_cpu(pcpu->lowcore);
226 if (pcpu == &pcpu_devices[0])
227 return;
228 free_page(pcpu->lowcore->panic_stack-PANIC_FRAME_OFFSET);
229 free_pages(pcpu->lowcore->async_stack-ASYNC_FRAME_OFFSET, ASYNC_ORDER);
230 free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
233 #endif /* CONFIG_HOTPLUG_CPU */
235 static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu)
237 struct _lowcore *lc = pcpu->lowcore;
239 if (MACHINE_HAS_TLB_LC)
240 cpumask_set_cpu(cpu, &init_mm.context.cpu_attach_mask);
241 cpumask_set_cpu(cpu, mm_cpumask(&init_mm));
242 atomic_inc(&init_mm.context.attach_count);
243 lc->cpu_nr = cpu;
244 lc->spinlock_lockval = arch_spin_lockval(cpu);
245 lc->percpu_offset = __per_cpu_offset[cpu];
246 lc->kernel_asce = S390_lowcore.kernel_asce;
247 lc->machine_flags = S390_lowcore.machine_flags;
248 lc->user_timer = lc->system_timer = lc->steal_timer = 0;
249 __ctl_store(lc->cregs_save_area, 0, 15);
250 save_access_regs((unsigned int *) lc->access_regs_save_area);
251 memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,
252 MAX_FACILITY_BIT/8);
255 static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk)
257 struct _lowcore *lc = pcpu->lowcore;
258 struct thread_info *ti = task_thread_info(tsk);
260 lc->kernel_stack = (unsigned long) task_stack_page(tsk)
261 + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
262 lc->thread_info = (unsigned long) task_thread_info(tsk);
263 lc->current_task = (unsigned long) tsk;
264 lc->user_timer = ti->user_timer;
265 lc->system_timer = ti->system_timer;
266 lc->steal_timer = 0;
269 static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data)
271 struct _lowcore *lc = pcpu->lowcore;
273 lc->restart_stack = lc->kernel_stack;
274 lc->restart_fn = (unsigned long) func;
275 lc->restart_data = (unsigned long) data;
276 lc->restart_source = -1UL;
277 pcpu_sigp_retry(pcpu, SIGP_RESTART, 0);
281 * Call function via PSW restart on pcpu and stop the current cpu.
283 static void pcpu_delegate(struct pcpu *pcpu, void (*func)(void *),
284 void *data, unsigned long stack)
286 struct _lowcore *lc = lowcore_ptr[pcpu - pcpu_devices];
287 unsigned long source_cpu = stap();
289 __load_psw_mask(PSW_KERNEL_BITS);
290 if (pcpu->address == source_cpu)
291 func(data); /* should not return */
292 /* Stop target cpu (if func returns this stops the current cpu). */
293 pcpu_sigp_retry(pcpu, SIGP_STOP, 0);
294 /* Restart func on the target cpu and stop the current cpu. */
295 mem_assign_absolute(lc->restart_stack, stack);
296 mem_assign_absolute(lc->restart_fn, (unsigned long) func);
297 mem_assign_absolute(lc->restart_data, (unsigned long) data);
298 mem_assign_absolute(lc->restart_source, source_cpu);
299 asm volatile(
300 "0: sigp 0,%0,%2 # sigp restart to target cpu\n"
301 " brc 2,0b # busy, try again\n"
302 "1: sigp 0,%1,%3 # sigp stop to current cpu\n"
303 " brc 2,1b # busy, try again\n"
304 : : "d" (pcpu->address), "d" (source_cpu),
305 "K" (SIGP_RESTART), "K" (SIGP_STOP)
306 : "0", "1", "cc");
307 for (;;) ;
311 * Enable additional logical cpus for multi-threading.
313 static int pcpu_set_smt(unsigned int mtid)
315 register unsigned long reg1 asm ("1") = (unsigned long) mtid;
316 int cc;
318 if (smp_cpu_mtid == mtid)
319 return 0;
320 asm volatile(
321 " sigp %1,0,%2 # sigp set multi-threading\n"
322 " ipm %0\n"
323 " srl %0,28\n"
324 : "=d" (cc) : "d" (reg1), "K" (SIGP_SET_MULTI_THREADING)
325 : "cc");
326 if (cc == 0) {
327 smp_cpu_mtid = mtid;
328 smp_cpu_mt_shift = 0;
329 while (smp_cpu_mtid >= (1U << smp_cpu_mt_shift))
330 smp_cpu_mt_shift++;
331 pcpu_devices[0].address = stap();
333 return cc;
337 * Call function on an online CPU.
339 void smp_call_online_cpu(void (*func)(void *), void *data)
341 struct pcpu *pcpu;
343 /* Use the current cpu if it is online. */
344 pcpu = pcpu_find_address(cpu_online_mask, stap());
345 if (!pcpu)
346 /* Use the first online cpu. */
347 pcpu = pcpu_devices + cpumask_first(cpu_online_mask);
348 pcpu_delegate(pcpu, func, data, (unsigned long) restart_stack);
352 * Call function on the ipl CPU.
354 void smp_call_ipl_cpu(void (*func)(void *), void *data)
356 pcpu_delegate(&pcpu_devices[0], func, data,
357 pcpu_devices->lowcore->panic_stack -
358 PANIC_FRAME_OFFSET + PAGE_SIZE);
361 int smp_find_processor_id(u16 address)
363 int cpu;
365 for_each_present_cpu(cpu)
366 if (pcpu_devices[cpu].address == address)
367 return cpu;
368 return -1;
371 int smp_vcpu_scheduled(int cpu)
373 return pcpu_running(pcpu_devices + cpu);
376 void smp_yield_cpu(int cpu)
378 if (MACHINE_HAS_DIAG9C)
379 asm volatile("diag %0,0,0x9c"
380 : : "d" (pcpu_devices[cpu].address));
381 else if (MACHINE_HAS_DIAG44)
382 asm volatile("diag 0,0,0x44");
386 * Send cpus emergency shutdown signal. This gives the cpus the
387 * opportunity to complete outstanding interrupts.
389 static void smp_emergency_stop(cpumask_t *cpumask)
391 u64 end;
392 int cpu;
394 end = get_tod_clock() + (1000000UL << 12);
395 for_each_cpu(cpu, cpumask) {
396 struct pcpu *pcpu = pcpu_devices + cpu;
397 set_bit(ec_stop_cpu, &pcpu->ec_mask);
398 while (__pcpu_sigp(pcpu->address, SIGP_EMERGENCY_SIGNAL,
399 0, NULL) == SIGP_CC_BUSY &&
400 get_tod_clock() < end)
401 cpu_relax();
403 while (get_tod_clock() < end) {
404 for_each_cpu(cpu, cpumask)
405 if (pcpu_stopped(pcpu_devices + cpu))
406 cpumask_clear_cpu(cpu, cpumask);
407 if (cpumask_empty(cpumask))
408 break;
409 cpu_relax();
414 * Stop all cpus but the current one.
416 void smp_send_stop(void)
418 cpumask_t cpumask;
419 int cpu;
421 /* Disable all interrupts/machine checks */
422 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
423 trace_hardirqs_off();
425 debug_set_critical();
426 cpumask_copy(&cpumask, cpu_online_mask);
427 cpumask_clear_cpu(smp_processor_id(), &cpumask);
429 if (oops_in_progress)
430 smp_emergency_stop(&cpumask);
432 /* stop all processors */
433 for_each_cpu(cpu, &cpumask) {
434 struct pcpu *pcpu = pcpu_devices + cpu;
435 pcpu_sigp_retry(pcpu, SIGP_STOP, 0);
436 while (!pcpu_stopped(pcpu))
437 cpu_relax();
442 * This is the main routine where commands issued by other
443 * cpus are handled.
445 static void smp_handle_ext_call(void)
447 unsigned long bits;
449 /* handle bit signal external calls */
450 bits = xchg(&pcpu_devices[smp_processor_id()].ec_mask, 0);
451 if (test_bit(ec_stop_cpu, &bits))
452 smp_stop_cpu();
453 if (test_bit(ec_schedule, &bits))
454 scheduler_ipi();
455 if (test_bit(ec_call_function_single, &bits))
456 generic_smp_call_function_single_interrupt();
459 static void do_ext_call_interrupt(struct ext_code ext_code,
460 unsigned int param32, unsigned long param64)
462 inc_irq_stat(ext_code.code == 0x1202 ? IRQEXT_EXC : IRQEXT_EMS);
463 smp_handle_ext_call();
466 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
468 int cpu;
470 for_each_cpu(cpu, mask)
471 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
474 void arch_send_call_function_single_ipi(int cpu)
476 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
480 * this function sends a 'reschedule' IPI to another CPU.
481 * it goes straight through and wastes no time serializing
482 * anything. Worst case is that we lose a reschedule ...
484 void smp_send_reschedule(int cpu)
486 pcpu_ec_call(pcpu_devices + cpu, ec_schedule);
490 * parameter area for the set/clear control bit callbacks
492 struct ec_creg_mask_parms {
493 unsigned long orval;
494 unsigned long andval;
495 int cr;
499 * callback for setting/clearing control bits
501 static void smp_ctl_bit_callback(void *info)
503 struct ec_creg_mask_parms *pp = info;
504 unsigned long cregs[16];
506 __ctl_store(cregs, 0, 15);
507 cregs[pp->cr] = (cregs[pp->cr] & pp->andval) | pp->orval;
508 __ctl_load(cregs, 0, 15);
512 * Set a bit in a control register of all cpus
514 void smp_ctl_set_bit(int cr, int bit)
516 struct ec_creg_mask_parms parms = { 1UL << bit, -1UL, cr };
518 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
520 EXPORT_SYMBOL(smp_ctl_set_bit);
523 * Clear a bit in a control register of all cpus
525 void smp_ctl_clear_bit(int cr, int bit)
527 struct ec_creg_mask_parms parms = { 0, ~(1UL << bit), cr };
529 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
531 EXPORT_SYMBOL(smp_ctl_clear_bit);
533 #ifdef CONFIG_CRASH_DUMP
535 static void __smp_store_cpu_state(struct save_area_ext *sa_ext, u16 address,
536 int is_boot_cpu)
538 void *lc = (void *)(unsigned long) store_prefix();
539 unsigned long vx_sa;
541 if (is_boot_cpu) {
542 /* Copy the registers of the boot CPU. */
543 copy_oldmem_page(1, (void *) &sa_ext->sa, sizeof(sa_ext->sa),
544 SAVE_AREA_BASE - PAGE_SIZE, 0);
545 if (MACHINE_HAS_VX)
546 save_vx_regs_safe(sa_ext->vx_regs);
547 return;
549 /* Get the registers of a non-boot cpu. */
550 __pcpu_sigp_relax(address, SIGP_STOP_AND_STORE_STATUS, 0, NULL);
551 memcpy_real(&sa_ext->sa, lc + SAVE_AREA_BASE, sizeof(sa_ext->sa));
552 if (!MACHINE_HAS_VX)
553 return;
554 /* Get the VX registers */
555 vx_sa = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
556 if (!vx_sa)
557 panic("could not allocate memory for VX save area\n");
558 __pcpu_sigp_relax(address, SIGP_STORE_ADDITIONAL_STATUS, vx_sa, NULL);
559 memcpy(sa_ext->vx_regs, (void *) vx_sa, sizeof(sa_ext->vx_regs));
560 memblock_free(vx_sa, PAGE_SIZE);
563 int smp_store_status(int cpu)
565 unsigned long vx_sa;
566 struct pcpu *pcpu;
568 pcpu = pcpu_devices + cpu;
569 if (__pcpu_sigp_relax(pcpu->address, SIGP_STOP_AND_STORE_STATUS,
570 0, NULL) != SIGP_CC_ORDER_CODE_ACCEPTED)
571 return -EIO;
572 if (!MACHINE_HAS_VX)
573 return 0;
574 vx_sa = __pa(pcpu->lowcore->vector_save_area_addr);
575 __pcpu_sigp_relax(pcpu->address, SIGP_STORE_ADDITIONAL_STATUS,
576 vx_sa, NULL);
577 return 0;
580 #endif /* CONFIG_CRASH_DUMP */
583 * Collect CPU state of the previous, crashed system.
584 * There are four cases:
585 * 1) standard zfcp dump
586 * condition: OLDMEM_BASE == NULL && ipl_info.type == IPL_TYPE_FCP_DUMP
587 * The state for all CPUs except the boot CPU needs to be collected
588 * with sigp stop-and-store-status. The boot CPU state is located in
589 * the absolute lowcore of the memory stored in the HSA. The zcore code
590 * will allocate the save area and copy the boot CPU state from the HSA.
591 * 2) stand-alone kdump for SCSI (zfcp dump with swapped memory)
592 * condition: OLDMEM_BASE != NULL && ipl_info.type == IPL_TYPE_FCP_DUMP
593 * The state for all CPUs except the boot CPU needs to be collected
594 * with sigp stop-and-store-status. The firmware or the boot-loader
595 * stored the registers of the boot CPU in the absolute lowcore in the
596 * memory of the old system.
597 * 3) kdump and the old kernel did not store the CPU state,
598 * or stand-alone kdump for DASD
599 * condition: OLDMEM_BASE != NULL && !is_kdump_kernel()
600 * The state for all CPUs except the boot CPU needs to be collected
601 * with sigp stop-and-store-status. The kexec code or the boot-loader
602 * stored the registers of the boot CPU in the memory of the old system.
603 * 4) kdump and the old kernel stored the CPU state
604 * condition: OLDMEM_BASE != NULL && is_kdump_kernel()
605 * The state of all CPUs is stored in ELF sections in the memory of the
606 * old system. The ELF sections are picked up by the crash_dump code
607 * via elfcorehdr_addr.
609 void __init smp_save_dump_cpus(void)
611 #ifdef CONFIG_CRASH_DUMP
612 int addr, cpu, boot_cpu_addr, max_cpu_addr;
613 struct save_area_ext *sa_ext;
614 bool is_boot_cpu;
616 if (is_kdump_kernel())
617 /* Previous system stored the CPU states. Nothing to do. */
618 return;
619 if (!(OLDMEM_BASE || ipl_info.type == IPL_TYPE_FCP_DUMP))
620 /* No previous system present, normal boot. */
621 return;
622 /* Set multi-threading state to the previous system. */
623 pcpu_set_smt(sclp.mtid_prev);
624 max_cpu_addr = SCLP_MAX_CORES << sclp.mtid_prev;
625 for (cpu = 0, addr = 0; addr <= max_cpu_addr; addr++) {
626 if (__pcpu_sigp_relax(addr, SIGP_SENSE, 0, NULL) ==
627 SIGP_CC_NOT_OPERATIONAL)
628 continue;
629 cpu += 1;
631 dump_save_areas.areas = (void *)memblock_alloc(sizeof(void *) * cpu, 8);
632 dump_save_areas.count = cpu;
633 boot_cpu_addr = stap();
634 for (cpu = 0, addr = 0; addr <= max_cpu_addr; addr++) {
635 if (__pcpu_sigp_relax(addr, SIGP_SENSE, 0, NULL) ==
636 SIGP_CC_NOT_OPERATIONAL)
637 continue;
638 sa_ext = (void *) memblock_alloc(sizeof(*sa_ext), 8);
639 dump_save_areas.areas[cpu] = sa_ext;
640 if (!sa_ext)
641 panic("could not allocate memory for save area\n");
642 is_boot_cpu = (addr == boot_cpu_addr);
643 cpu += 1;
644 if (is_boot_cpu && !OLDMEM_BASE)
645 /* Skip boot CPU for standard zfcp dump. */
646 continue;
647 /* Get state for this CPU. */
648 __smp_store_cpu_state(sa_ext, addr, is_boot_cpu);
650 diag308_reset();
651 pcpu_set_smt(0);
652 #endif /* CONFIG_CRASH_DUMP */
655 void smp_cpu_set_polarization(int cpu, int val)
657 pcpu_devices[cpu].polarization = val;
660 int smp_cpu_get_polarization(int cpu)
662 return pcpu_devices[cpu].polarization;
665 static struct sclp_core_info *smp_get_core_info(void)
667 static int use_sigp_detection;
668 struct sclp_core_info *info;
669 int address;
671 info = kzalloc(sizeof(*info), GFP_KERNEL);
672 if (info && (use_sigp_detection || sclp_get_core_info(info))) {
673 use_sigp_detection = 1;
674 for (address = 0;
675 address < (SCLP_MAX_CORES << smp_cpu_mt_shift);
676 address += (1U << smp_cpu_mt_shift)) {
677 if (__pcpu_sigp_relax(address, SIGP_SENSE, 0, NULL) ==
678 SIGP_CC_NOT_OPERATIONAL)
679 continue;
680 info->core[info->configured].core_id =
681 address >> smp_cpu_mt_shift;
682 info->configured++;
684 info->combined = info->configured;
686 return info;
689 static int smp_add_present_cpu(int cpu);
691 static int __smp_rescan_cpus(struct sclp_core_info *info, int sysfs_add)
693 struct pcpu *pcpu;
694 cpumask_t avail;
695 int cpu, nr, i, j;
696 u16 address;
698 nr = 0;
699 cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask);
700 cpu = cpumask_first(&avail);
701 for (i = 0; (i < info->combined) && (cpu < nr_cpu_ids); i++) {
702 if (sclp.has_core_type && info->core[i].type != boot_core_type)
703 continue;
704 address = info->core[i].core_id << smp_cpu_mt_shift;
705 for (j = 0; j <= smp_cpu_mtid; j++) {
706 if (pcpu_find_address(cpu_present_mask, address + j))
707 continue;
708 pcpu = pcpu_devices + cpu;
709 pcpu->address = address + j;
710 pcpu->state =
711 (cpu >= info->configured*(smp_cpu_mtid + 1)) ?
712 CPU_STATE_STANDBY : CPU_STATE_CONFIGURED;
713 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
714 set_cpu_present(cpu, true);
715 if (sysfs_add && smp_add_present_cpu(cpu) != 0)
716 set_cpu_present(cpu, false);
717 else
718 nr++;
719 cpu = cpumask_next(cpu, &avail);
720 if (cpu >= nr_cpu_ids)
721 break;
724 return nr;
727 static void __init smp_detect_cpus(void)
729 unsigned int cpu, mtid, c_cpus, s_cpus;
730 struct sclp_core_info *info;
731 u16 address;
733 /* Get CPU information */
734 info = smp_get_core_info();
735 if (!info)
736 panic("smp_detect_cpus failed to allocate memory\n");
738 /* Find boot CPU type */
739 if (sclp.has_core_type) {
740 address = stap();
741 for (cpu = 0; cpu < info->combined; cpu++)
742 if (info->core[cpu].core_id == address) {
743 /* The boot cpu dictates the cpu type. */
744 boot_core_type = info->core[cpu].type;
745 break;
747 if (cpu >= info->combined)
748 panic("Could not find boot CPU type");
751 /* Set multi-threading state for the current system */
752 mtid = boot_core_type ? sclp.mtid : sclp.mtid_cp;
753 mtid = (mtid < smp_max_threads) ? mtid : smp_max_threads - 1;
754 pcpu_set_smt(mtid);
756 /* Print number of CPUs */
757 c_cpus = s_cpus = 0;
758 for (cpu = 0; cpu < info->combined; cpu++) {
759 if (sclp.has_core_type &&
760 info->core[cpu].type != boot_core_type)
761 continue;
762 if (cpu < info->configured)
763 c_cpus += smp_cpu_mtid + 1;
764 else
765 s_cpus += smp_cpu_mtid + 1;
767 pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
769 /* Add CPUs present at boot */
770 get_online_cpus();
771 __smp_rescan_cpus(info, 0);
772 put_online_cpus();
773 kfree(info);
777 * Activate a secondary processor.
779 static void smp_start_secondary(void *cpuvoid)
781 S390_lowcore.last_update_clock = get_tod_clock();
782 S390_lowcore.restart_stack = (unsigned long) restart_stack;
783 S390_lowcore.restart_fn = (unsigned long) do_restart;
784 S390_lowcore.restart_data = 0;
785 S390_lowcore.restart_source = -1UL;
786 restore_access_regs(S390_lowcore.access_regs_save_area);
787 __ctl_load(S390_lowcore.cregs_save_area, 0, 15);
788 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
789 cpu_init();
790 preempt_disable();
791 init_cpu_timer();
792 vtime_init();
793 pfault_init();
794 notify_cpu_starting(smp_processor_id());
795 set_cpu_online(smp_processor_id(), true);
796 inc_irq_stat(CPU_RST);
797 local_irq_enable();
798 cpu_startup_entry(CPUHP_ONLINE);
801 /* Upping and downing of CPUs */
802 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
804 struct pcpu *pcpu;
805 int base, i, rc;
807 pcpu = pcpu_devices + cpu;
808 if (pcpu->state != CPU_STATE_CONFIGURED)
809 return -EIO;
810 base = cpu - (cpu % (smp_cpu_mtid + 1));
811 for (i = 0; i <= smp_cpu_mtid; i++) {
812 if (base + i < nr_cpu_ids)
813 if (cpu_online(base + i))
814 break;
817 * If this is the first CPU of the core to get online
818 * do an initial CPU reset.
820 if (i > smp_cpu_mtid &&
821 pcpu_sigp_retry(pcpu_devices + base, SIGP_INITIAL_CPU_RESET, 0) !=
822 SIGP_CC_ORDER_CODE_ACCEPTED)
823 return -EIO;
825 rc = pcpu_alloc_lowcore(pcpu, cpu);
826 if (rc)
827 return rc;
828 pcpu_prepare_secondary(pcpu, cpu);
829 pcpu_attach_task(pcpu, tidle);
830 pcpu_start_fn(pcpu, smp_start_secondary, NULL);
831 /* Wait until cpu puts itself in the online & active maps */
832 while (!cpu_online(cpu) || !cpu_active(cpu))
833 cpu_relax();
834 return 0;
837 static unsigned int setup_possible_cpus __initdata;
839 static int __init _setup_possible_cpus(char *s)
841 get_option(&s, &setup_possible_cpus);
842 return 0;
844 early_param("possible_cpus", _setup_possible_cpus);
846 #ifdef CONFIG_HOTPLUG_CPU
848 int __cpu_disable(void)
850 unsigned long cregs[16];
852 /* Handle possible pending IPIs */
853 smp_handle_ext_call();
854 set_cpu_online(smp_processor_id(), false);
855 /* Disable pseudo page faults on this cpu. */
856 pfault_fini();
857 /* Disable interrupt sources via control register. */
858 __ctl_store(cregs, 0, 15);
859 cregs[0] &= ~0x0000ee70UL; /* disable all external interrupts */
860 cregs[6] &= ~0xff000000UL; /* disable all I/O interrupts */
861 cregs[14] &= ~0x1f000000UL; /* disable most machine checks */
862 __ctl_load(cregs, 0, 15);
863 clear_cpu_flag(CIF_NOHZ_DELAY);
864 return 0;
867 void __cpu_die(unsigned int cpu)
869 struct pcpu *pcpu;
871 /* Wait until target cpu is down */
872 pcpu = pcpu_devices + cpu;
873 while (!pcpu_stopped(pcpu))
874 cpu_relax();
875 pcpu_free_lowcore(pcpu);
876 atomic_dec(&init_mm.context.attach_count);
877 cpumask_clear_cpu(cpu, mm_cpumask(&init_mm));
878 if (MACHINE_HAS_TLB_LC)
879 cpumask_clear_cpu(cpu, &init_mm.context.cpu_attach_mask);
882 void __noreturn cpu_die(void)
884 idle_task_exit();
885 pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0);
886 for (;;) ;
889 #endif /* CONFIG_HOTPLUG_CPU */
891 void __init smp_fill_possible_mask(void)
893 unsigned int possible, sclp_max, cpu;
895 sclp_max = max(sclp.mtid, sclp.mtid_cp) + 1;
896 sclp_max = min(smp_max_threads, sclp_max);
897 sclp_max = sclp.max_cores * sclp_max ?: nr_cpu_ids;
898 possible = setup_possible_cpus ?: nr_cpu_ids;
899 possible = min(possible, sclp_max);
900 for (cpu = 0; cpu < possible && cpu < nr_cpu_ids; cpu++)
901 set_cpu_possible(cpu, true);
904 void __init smp_prepare_cpus(unsigned int max_cpus)
906 /* request the 0x1201 emergency signal external interrupt */
907 if (register_external_irq(EXT_IRQ_EMERGENCY_SIG, do_ext_call_interrupt))
908 panic("Couldn't request external interrupt 0x1201");
909 /* request the 0x1202 external call external interrupt */
910 if (register_external_irq(EXT_IRQ_EXTERNAL_CALL, do_ext_call_interrupt))
911 panic("Couldn't request external interrupt 0x1202");
912 smp_detect_cpus();
915 void __init smp_prepare_boot_cpu(void)
917 struct pcpu *pcpu = pcpu_devices;
919 pcpu->state = CPU_STATE_CONFIGURED;
920 pcpu->address = stap();
921 pcpu->lowcore = (struct _lowcore *)(unsigned long) store_prefix();
922 S390_lowcore.percpu_offset = __per_cpu_offset[0];
923 smp_cpu_set_polarization(0, POLARIZATION_UNKNOWN);
924 set_cpu_present(0, true);
925 set_cpu_online(0, true);
928 void __init smp_cpus_done(unsigned int max_cpus)
932 void __init smp_setup_processor_id(void)
934 S390_lowcore.cpu_nr = 0;
935 S390_lowcore.spinlock_lockval = arch_spin_lockval(0);
939 * the frequency of the profiling timer can be changed
940 * by writing a multiplier value into /proc/profile.
942 * usually you want to run this on all CPUs ;)
944 int setup_profiling_timer(unsigned int multiplier)
946 return 0;
949 #ifdef CONFIG_HOTPLUG_CPU
950 static ssize_t cpu_configure_show(struct device *dev,
951 struct device_attribute *attr, char *buf)
953 ssize_t count;
955 mutex_lock(&smp_cpu_state_mutex);
956 count = sprintf(buf, "%d\n", pcpu_devices[dev->id].state);
957 mutex_unlock(&smp_cpu_state_mutex);
958 return count;
961 static ssize_t cpu_configure_store(struct device *dev,
962 struct device_attribute *attr,
963 const char *buf, size_t count)
965 struct pcpu *pcpu;
966 int cpu, val, rc, i;
967 char delim;
969 if (sscanf(buf, "%d %c", &val, &delim) != 1)
970 return -EINVAL;
971 if (val != 0 && val != 1)
972 return -EINVAL;
973 get_online_cpus();
974 mutex_lock(&smp_cpu_state_mutex);
975 rc = -EBUSY;
976 /* disallow configuration changes of online cpus and cpu 0 */
977 cpu = dev->id;
978 cpu -= cpu % (smp_cpu_mtid + 1);
979 if (cpu == 0)
980 goto out;
981 for (i = 0; i <= smp_cpu_mtid; i++)
982 if (cpu_online(cpu + i))
983 goto out;
984 pcpu = pcpu_devices + cpu;
985 rc = 0;
986 switch (val) {
987 case 0:
988 if (pcpu->state != CPU_STATE_CONFIGURED)
989 break;
990 rc = sclp_core_deconfigure(pcpu->address >> smp_cpu_mt_shift);
991 if (rc)
992 break;
993 for (i = 0; i <= smp_cpu_mtid; i++) {
994 if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i))
995 continue;
996 pcpu[i].state = CPU_STATE_STANDBY;
997 smp_cpu_set_polarization(cpu + i,
998 POLARIZATION_UNKNOWN);
1000 topology_expect_change();
1001 break;
1002 case 1:
1003 if (pcpu->state != CPU_STATE_STANDBY)
1004 break;
1005 rc = sclp_core_configure(pcpu->address >> smp_cpu_mt_shift);
1006 if (rc)
1007 break;
1008 for (i = 0; i <= smp_cpu_mtid; i++) {
1009 if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i))
1010 continue;
1011 pcpu[i].state = CPU_STATE_CONFIGURED;
1012 smp_cpu_set_polarization(cpu + i,
1013 POLARIZATION_UNKNOWN);
1015 topology_expect_change();
1016 break;
1017 default:
1018 break;
1020 out:
1021 mutex_unlock(&smp_cpu_state_mutex);
1022 put_online_cpus();
1023 return rc ? rc : count;
1025 static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
1026 #endif /* CONFIG_HOTPLUG_CPU */
1028 static ssize_t show_cpu_address(struct device *dev,
1029 struct device_attribute *attr, char *buf)
1031 return sprintf(buf, "%d\n", pcpu_devices[dev->id].address);
1033 static DEVICE_ATTR(address, 0444, show_cpu_address, NULL);
1035 static struct attribute *cpu_common_attrs[] = {
1036 #ifdef CONFIG_HOTPLUG_CPU
1037 &dev_attr_configure.attr,
1038 #endif
1039 &dev_attr_address.attr,
1040 NULL,
1043 static struct attribute_group cpu_common_attr_group = {
1044 .attrs = cpu_common_attrs,
1047 static struct attribute *cpu_online_attrs[] = {
1048 &dev_attr_idle_count.attr,
1049 &dev_attr_idle_time_us.attr,
1050 NULL,
1053 static struct attribute_group cpu_online_attr_group = {
1054 .attrs = cpu_online_attrs,
1057 static int smp_cpu_notify(struct notifier_block *self, unsigned long action,
1058 void *hcpu)
1060 unsigned int cpu = (unsigned int)(long)hcpu;
1061 struct device *s = &per_cpu(cpu_device, cpu)->dev;
1062 int err = 0;
1064 switch (action & ~CPU_TASKS_FROZEN) {
1065 case CPU_ONLINE:
1066 err = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
1067 break;
1068 case CPU_DEAD:
1069 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
1070 break;
1072 return notifier_from_errno(err);
1075 static int smp_add_present_cpu(int cpu)
1077 struct device *s;
1078 struct cpu *c;
1079 int rc;
1081 c = kzalloc(sizeof(*c), GFP_KERNEL);
1082 if (!c)
1083 return -ENOMEM;
1084 per_cpu(cpu_device, cpu) = c;
1085 s = &c->dev;
1086 c->hotpluggable = 1;
1087 rc = register_cpu(c, cpu);
1088 if (rc)
1089 goto out;
1090 rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
1091 if (rc)
1092 goto out_cpu;
1093 if (cpu_online(cpu)) {
1094 rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
1095 if (rc)
1096 goto out_online;
1098 rc = topology_cpu_init(c);
1099 if (rc)
1100 goto out_topology;
1101 return 0;
1103 out_topology:
1104 if (cpu_online(cpu))
1105 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
1106 out_online:
1107 sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
1108 out_cpu:
1109 #ifdef CONFIG_HOTPLUG_CPU
1110 unregister_cpu(c);
1111 #endif
1112 out:
1113 return rc;
1116 #ifdef CONFIG_HOTPLUG_CPU
1118 int __ref smp_rescan_cpus(void)
1120 struct sclp_core_info *info;
1121 int nr;
1123 info = smp_get_core_info();
1124 if (!info)
1125 return -ENOMEM;
1126 get_online_cpus();
1127 mutex_lock(&smp_cpu_state_mutex);
1128 nr = __smp_rescan_cpus(info, 1);
1129 mutex_unlock(&smp_cpu_state_mutex);
1130 put_online_cpus();
1131 kfree(info);
1132 if (nr)
1133 topology_schedule_update();
1134 return 0;
1137 static ssize_t __ref rescan_store(struct device *dev,
1138 struct device_attribute *attr,
1139 const char *buf,
1140 size_t count)
1142 int rc;
1144 rc = smp_rescan_cpus();
1145 return rc ? rc : count;
1147 static DEVICE_ATTR(rescan, 0200, NULL, rescan_store);
1148 #endif /* CONFIG_HOTPLUG_CPU */
1150 static int __init s390_smp_init(void)
1152 int cpu, rc = 0;
1154 #ifdef CONFIG_HOTPLUG_CPU
1155 rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan);
1156 if (rc)
1157 return rc;
1158 #endif
1159 cpu_notifier_register_begin();
1160 for_each_present_cpu(cpu) {
1161 rc = smp_add_present_cpu(cpu);
1162 if (rc)
1163 goto out;
1166 __hotcpu_notifier(smp_cpu_notify, 0);
1168 out:
1169 cpu_notifier_register_done();
1170 return rc;
1172 subsys_initcall(s390_smp_init);