1 // SPDX-License-Identifier: GPL-2.0
3 * SMP related functions
5 * Copyright IBM Corp. 1999, 2012
6 * Author(s): Denis Joseph Barrow,
7 * Martin Schwidefsky <schwidefsky@de.ibm.com>,
8 * Heiko Carstens <heiko.carstens@de.ibm.com>,
10 * based on other smp stuff by
11 * (c) 1995 Alan Cox, CymruNET Ltd <alan@cymru.net>
12 * (c) 1998 Ingo Molnar
14 * The code outside of smp.c uses logical cpu numbers, only smp.c does
15 * the translation of logical to physical cpu ids. All new code that
16 * operates on physical cpu numbers needs to go into smp.c.
19 #define KMSG_COMPONENT "cpu"
20 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
22 #include <linux/workqueue.h>
23 #include <linux/bootmem.h>
24 #include <linux/export.h>
25 #include <linux/init.h>
27 #include <linux/err.h>
28 #include <linux/spinlock.h>
29 #include <linux/kernel_stat.h>
30 #include <linux/kmemleak.h>
31 #include <linux/delay.h>
32 #include <linux/interrupt.h>
33 #include <linux/irqflags.h>
34 #include <linux/cpu.h>
35 #include <linux/slab.h>
36 #include <linux/sched/hotplug.h>
37 #include <linux/sched/task_stack.h>
38 #include <linux/crash_dump.h>
39 #include <linux/memblock.h>
40 #include <linux/kprobes.h>
41 #include <asm/asm-offsets.h>
43 #include <asm/switch_to.h>
44 #include <asm/facility.h>
46 #include <asm/setup.h>
48 #include <asm/tlbflush.h>
49 #include <asm/vtimer.h>
50 #include <asm/lowcore.h>
53 #include <asm/debug.h>
54 #include <asm/os_info.h>
58 #include <asm/topology.h>
63 ec_call_function_single
,
72 static DEFINE_PER_CPU(struct cpu
*, cpu_device
);
75 struct lowcore
*lowcore
; /* lowcore page(s) for the cpu */
76 unsigned long ec_mask
; /* bit mask for ec_xxx functions */
77 unsigned long ec_clk
; /* sigp timestamp for ec_xxx */
78 signed char state
; /* physical cpu state */
79 signed char polarization
; /* physical polarization */
80 u16 address
; /* physical cpu address */
83 static u8 boot_core_type
;
84 static struct pcpu pcpu_devices
[NR_CPUS
];
86 unsigned int smp_cpu_mt_shift
;
87 EXPORT_SYMBOL(smp_cpu_mt_shift
);
89 unsigned int smp_cpu_mtid
;
90 EXPORT_SYMBOL(smp_cpu_mtid
);
92 #ifdef CONFIG_CRASH_DUMP
93 __vector128 __initdata boot_cpu_vector_save_area
[__NUM_VXRS
];
96 static unsigned int smp_max_threads __initdata
= -1U;
98 static int __init
early_nosmt(char *s
)
103 early_param("nosmt", early_nosmt
);
105 static int __init
early_smt(char *s
)
107 get_option(&s
, &smp_max_threads
);
110 early_param("smt", early_smt
);
113 * The smp_cpu_state_mutex must be held when changing the state or polarization
114 * member of a pcpu data structure within the pcpu_devices arreay.
116 DEFINE_MUTEX(smp_cpu_state_mutex
);
119 * Signal processor helper functions.
121 static inline int __pcpu_sigp_relax(u16 addr
, u8 order
, unsigned long parm
)
126 cc
= __pcpu_sigp(addr
, order
, parm
, NULL
);
127 if (cc
!= SIGP_CC_BUSY
)
133 static int pcpu_sigp_retry(struct pcpu
*pcpu
, u8 order
, u32 parm
)
137 for (retry
= 0; ; retry
++) {
138 cc
= __pcpu_sigp(pcpu
->address
, order
, parm
, NULL
);
139 if (cc
!= SIGP_CC_BUSY
)
147 static inline int pcpu_stopped(struct pcpu
*pcpu
)
149 u32
uninitialized_var(status
);
151 if (__pcpu_sigp(pcpu
->address
, SIGP_SENSE
,
152 0, &status
) != SIGP_CC_STATUS_STORED
)
154 return !!(status
& (SIGP_STATUS_CHECK_STOP
|SIGP_STATUS_STOPPED
));
157 static inline int pcpu_running(struct pcpu
*pcpu
)
159 if (__pcpu_sigp(pcpu
->address
, SIGP_SENSE_RUNNING
,
160 0, NULL
) != SIGP_CC_STATUS_STORED
)
162 /* Status stored condition code is equivalent to cpu not running. */
167 * Find struct pcpu by cpu address.
169 static struct pcpu
*pcpu_find_address(const struct cpumask
*mask
, u16 address
)
173 for_each_cpu(cpu
, mask
)
174 if (pcpu_devices
[cpu
].address
== address
)
175 return pcpu_devices
+ cpu
;
179 static void pcpu_ec_call(struct pcpu
*pcpu
, int ec_bit
)
183 if (test_and_set_bit(ec_bit
, &pcpu
->ec_mask
))
185 order
= pcpu_running(pcpu
) ? SIGP_EXTERNAL_CALL
: SIGP_EMERGENCY_SIGNAL
;
186 pcpu
->ec_clk
= get_tod_clock_fast();
187 pcpu_sigp_retry(pcpu
, order
, 0);
190 #define ASYNC_FRAME_OFFSET (ASYNC_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE)
191 #define PANIC_FRAME_OFFSET (PAGE_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE)
193 static int pcpu_alloc_lowcore(struct pcpu
*pcpu
, int cpu
)
195 unsigned long async_stack
, panic_stack
;
198 if (pcpu
!= &pcpu_devices
[0]) {
199 pcpu
->lowcore
= (struct lowcore
*)
200 __get_free_pages(GFP_KERNEL
| GFP_DMA
, LC_ORDER
);
201 async_stack
= __get_free_pages(GFP_KERNEL
, ASYNC_ORDER
);
202 panic_stack
= __get_free_page(GFP_KERNEL
);
203 if (!pcpu
->lowcore
|| !panic_stack
|| !async_stack
)
206 async_stack
= pcpu
->lowcore
->async_stack
- ASYNC_FRAME_OFFSET
;
207 panic_stack
= pcpu
->lowcore
->panic_stack
- PANIC_FRAME_OFFSET
;
210 memcpy(lc
, &S390_lowcore
, 512);
211 memset((char *) lc
+ 512, 0, sizeof(*lc
) - 512);
212 lc
->async_stack
= async_stack
+ ASYNC_FRAME_OFFSET
;
213 lc
->panic_stack
= panic_stack
+ PANIC_FRAME_OFFSET
;
215 lc
->spinlock_lockval
= arch_spin_lockval(cpu
);
216 lc
->spinlock_index
= 0;
217 lc
->br_r1_trampoline
= 0x07f1; /* br %r1 */
218 if (nmi_alloc_per_cpu(lc
))
220 if (vdso_alloc_per_cpu(lc
))
222 lowcore_ptr
[cpu
] = lc
;
223 pcpu_sigp_retry(pcpu
, SIGP_SET_PREFIX
, (u32
)(unsigned long) lc
);
227 nmi_free_per_cpu(lc
);
229 if (pcpu
!= &pcpu_devices
[0]) {
230 free_page(panic_stack
);
231 free_pages(async_stack
, ASYNC_ORDER
);
232 free_pages((unsigned long) pcpu
->lowcore
, LC_ORDER
);
237 #ifdef CONFIG_HOTPLUG_CPU
239 static void pcpu_free_lowcore(struct pcpu
*pcpu
)
241 pcpu_sigp_retry(pcpu
, SIGP_SET_PREFIX
, 0);
242 lowcore_ptr
[pcpu
- pcpu_devices
] = NULL
;
243 vdso_free_per_cpu(pcpu
->lowcore
);
244 nmi_free_per_cpu(pcpu
->lowcore
);
245 if (pcpu
== &pcpu_devices
[0])
247 free_page(pcpu
->lowcore
->panic_stack
-PANIC_FRAME_OFFSET
);
248 free_pages(pcpu
->lowcore
->async_stack
-ASYNC_FRAME_OFFSET
, ASYNC_ORDER
);
249 free_pages((unsigned long) pcpu
->lowcore
, LC_ORDER
);
252 #endif /* CONFIG_HOTPLUG_CPU */
254 static void pcpu_prepare_secondary(struct pcpu
*pcpu
, int cpu
)
256 struct lowcore
*lc
= pcpu
->lowcore
;
258 cpumask_set_cpu(cpu
, &init_mm
.context
.cpu_attach_mask
);
259 cpumask_set_cpu(cpu
, mm_cpumask(&init_mm
));
261 lc
->spinlock_lockval
= arch_spin_lockval(cpu
);
262 lc
->spinlock_index
= 0;
263 lc
->percpu_offset
= __per_cpu_offset
[cpu
];
264 lc
->kernel_asce
= S390_lowcore
.kernel_asce
;
265 lc
->user_asce
= S390_lowcore
.kernel_asce
;
266 lc
->machine_flags
= S390_lowcore
.machine_flags
;
267 lc
->user_timer
= lc
->system_timer
= lc
->steal_timer
= 0;
268 __ctl_store(lc
->cregs_save_area
, 0, 15);
269 lc
->cregs_save_area
[1] = lc
->kernel_asce
;
270 lc
->cregs_save_area
[7] = lc
->vdso_asce
;
271 save_access_regs((unsigned int *) lc
->access_regs_save_area
);
272 memcpy(lc
->stfle_fac_list
, S390_lowcore
.stfle_fac_list
,
273 sizeof(lc
->stfle_fac_list
));
274 memcpy(lc
->alt_stfle_fac_list
, S390_lowcore
.alt_stfle_fac_list
,
275 sizeof(lc
->alt_stfle_fac_list
));
276 arch_spin_lock_setup(cpu
);
279 static void pcpu_attach_task(struct pcpu
*pcpu
, struct task_struct
*tsk
)
281 struct lowcore
*lc
= pcpu
->lowcore
;
283 lc
->kernel_stack
= (unsigned long) task_stack_page(tsk
)
284 + THREAD_SIZE
- STACK_FRAME_OVERHEAD
- sizeof(struct pt_regs
);
285 lc
->current_task
= (unsigned long) tsk
;
287 lc
->current_pid
= tsk
->pid
;
288 lc
->user_timer
= tsk
->thread
.user_timer
;
289 lc
->guest_timer
= tsk
->thread
.guest_timer
;
290 lc
->system_timer
= tsk
->thread
.system_timer
;
291 lc
->hardirq_timer
= tsk
->thread
.hardirq_timer
;
292 lc
->softirq_timer
= tsk
->thread
.softirq_timer
;
296 static void pcpu_start_fn(struct pcpu
*pcpu
, void (*func
)(void *), void *data
)
298 struct lowcore
*lc
= pcpu
->lowcore
;
300 lc
->restart_stack
= lc
->kernel_stack
;
301 lc
->restart_fn
= (unsigned long) func
;
302 lc
->restart_data
= (unsigned long) data
;
303 lc
->restart_source
= -1UL;
304 pcpu_sigp_retry(pcpu
, SIGP_RESTART
, 0);
308 * Call function via PSW restart on pcpu and stop the current cpu.
310 static void pcpu_delegate(struct pcpu
*pcpu
, void (*func
)(void *),
311 void *data
, unsigned long stack
)
313 struct lowcore
*lc
= lowcore_ptr
[pcpu
- pcpu_devices
];
314 unsigned long source_cpu
= stap();
316 __load_psw_mask(PSW_KERNEL_BITS
);
317 if (pcpu
->address
== source_cpu
)
318 func(data
); /* should not return */
319 /* Stop target cpu (if func returns this stops the current cpu). */
320 pcpu_sigp_retry(pcpu
, SIGP_STOP
, 0);
321 /* Restart func on the target cpu and stop the current cpu. */
322 mem_assign_absolute(lc
->restart_stack
, stack
);
323 mem_assign_absolute(lc
->restart_fn
, (unsigned long) func
);
324 mem_assign_absolute(lc
->restart_data
, (unsigned long) data
);
325 mem_assign_absolute(lc
->restart_source
, source_cpu
);
328 "0: sigp 0,%0,%2 # sigp restart to target cpu\n"
329 " brc 2,0b # busy, try again\n"
330 "1: sigp 0,%1,%3 # sigp stop to current cpu\n"
331 " brc 2,1b # busy, try again\n"
332 : : "d" (pcpu
->address
), "d" (source_cpu
),
333 "K" (SIGP_RESTART
), "K" (SIGP_STOP
)
339 * Enable additional logical cpus for multi-threading.
341 static int pcpu_set_smt(unsigned int mtid
)
345 if (smp_cpu_mtid
== mtid
)
347 cc
= __pcpu_sigp(0, SIGP_SET_MULTI_THREADING
, mtid
, NULL
);
350 smp_cpu_mt_shift
= 0;
351 while (smp_cpu_mtid
>= (1U << smp_cpu_mt_shift
))
353 pcpu_devices
[0].address
= stap();
359 * Call function on an online CPU.
361 void smp_call_online_cpu(void (*func
)(void *), void *data
)
365 /* Use the current cpu if it is online. */
366 pcpu
= pcpu_find_address(cpu_online_mask
, stap());
368 /* Use the first online cpu. */
369 pcpu
= pcpu_devices
+ cpumask_first(cpu_online_mask
);
370 pcpu_delegate(pcpu
, func
, data
, (unsigned long) restart_stack
);
374 * Call function on the ipl CPU.
376 void smp_call_ipl_cpu(void (*func
)(void *), void *data
)
378 struct lowcore
*lc
= pcpu_devices
->lowcore
;
380 if (pcpu_devices
[0].address
== stap())
383 pcpu_delegate(&pcpu_devices
[0], func
, data
,
384 lc
->panic_stack
- PANIC_FRAME_OFFSET
+ PAGE_SIZE
);
387 int smp_find_processor_id(u16 address
)
391 for_each_present_cpu(cpu
)
392 if (pcpu_devices
[cpu
].address
== address
)
397 bool arch_vcpu_is_preempted(int cpu
)
399 if (test_cpu_flag_of(CIF_ENABLED_WAIT
, cpu
))
401 if (pcpu_running(pcpu_devices
+ cpu
))
405 EXPORT_SYMBOL(arch_vcpu_is_preempted
);
407 void smp_yield_cpu(int cpu
)
409 if (MACHINE_HAS_DIAG9C
) {
410 diag_stat_inc_norecursion(DIAG_STAT_X09C
);
411 asm volatile("diag %0,0,0x9c"
412 : : "d" (pcpu_devices
[cpu
].address
));
413 } else if (MACHINE_HAS_DIAG44
) {
414 diag_stat_inc_norecursion(DIAG_STAT_X044
);
415 asm volatile("diag 0,0,0x44");
420 * Send cpus emergency shutdown signal. This gives the cpus the
421 * opportunity to complete outstanding interrupts.
423 void notrace
smp_emergency_stop(void)
429 cpumask_copy(&cpumask
, cpu_online_mask
);
430 cpumask_clear_cpu(smp_processor_id(), &cpumask
);
432 end
= get_tod_clock() + (1000000UL << 12);
433 for_each_cpu(cpu
, &cpumask
) {
434 struct pcpu
*pcpu
= pcpu_devices
+ cpu
;
435 set_bit(ec_stop_cpu
, &pcpu
->ec_mask
);
436 while (__pcpu_sigp(pcpu
->address
, SIGP_EMERGENCY_SIGNAL
,
437 0, NULL
) == SIGP_CC_BUSY
&&
438 get_tod_clock() < end
)
441 while (get_tod_clock() < end
) {
442 for_each_cpu(cpu
, &cpumask
)
443 if (pcpu_stopped(pcpu_devices
+ cpu
))
444 cpumask_clear_cpu(cpu
, &cpumask
);
445 if (cpumask_empty(&cpumask
))
450 NOKPROBE_SYMBOL(smp_emergency_stop
);
453 * Stop all cpus but the current one.
455 void smp_send_stop(void)
459 /* Disable all interrupts/machine checks */
460 __load_psw_mask(PSW_KERNEL_BITS
| PSW_MASK_DAT
);
461 trace_hardirqs_off();
463 debug_set_critical();
465 if (oops_in_progress
)
466 smp_emergency_stop();
468 /* stop all processors */
469 for_each_online_cpu(cpu
) {
470 if (cpu
== smp_processor_id())
472 pcpu_sigp_retry(pcpu_devices
+ cpu
, SIGP_STOP
, 0);
473 while (!pcpu_stopped(pcpu_devices
+ cpu
))
479 * This is the main routine where commands issued by other
482 static void smp_handle_ext_call(void)
486 /* handle bit signal external calls */
487 bits
= xchg(&pcpu_devices
[smp_processor_id()].ec_mask
, 0);
488 if (test_bit(ec_stop_cpu
, &bits
))
490 if (test_bit(ec_schedule
, &bits
))
492 if (test_bit(ec_call_function_single
, &bits
))
493 generic_smp_call_function_single_interrupt();
496 static void do_ext_call_interrupt(struct ext_code ext_code
,
497 unsigned int param32
, unsigned long param64
)
499 inc_irq_stat(ext_code
.code
== 0x1202 ? IRQEXT_EXC
: IRQEXT_EMS
);
500 smp_handle_ext_call();
503 void arch_send_call_function_ipi_mask(const struct cpumask
*mask
)
507 for_each_cpu(cpu
, mask
)
508 pcpu_ec_call(pcpu_devices
+ cpu
, ec_call_function_single
);
511 void arch_send_call_function_single_ipi(int cpu
)
513 pcpu_ec_call(pcpu_devices
+ cpu
, ec_call_function_single
);
517 * this function sends a 'reschedule' IPI to another CPU.
518 * it goes straight through and wastes no time serializing
519 * anything. Worst case is that we lose a reschedule ...
521 void smp_send_reschedule(int cpu
)
523 pcpu_ec_call(pcpu_devices
+ cpu
, ec_schedule
);
527 * parameter area for the set/clear control bit callbacks
529 struct ec_creg_mask_parms
{
531 unsigned long andval
;
536 * callback for setting/clearing control bits
538 static void smp_ctl_bit_callback(void *info
)
540 struct ec_creg_mask_parms
*pp
= info
;
541 unsigned long cregs
[16];
543 __ctl_store(cregs
, 0, 15);
544 cregs
[pp
->cr
] = (cregs
[pp
->cr
] & pp
->andval
) | pp
->orval
;
545 __ctl_load(cregs
, 0, 15);
549 * Set a bit in a control register of all cpus
551 void smp_ctl_set_bit(int cr
, int bit
)
553 struct ec_creg_mask_parms parms
= { 1UL << bit
, -1UL, cr
};
555 on_each_cpu(smp_ctl_bit_callback
, &parms
, 1);
557 EXPORT_SYMBOL(smp_ctl_set_bit
);
560 * Clear a bit in a control register of all cpus
562 void smp_ctl_clear_bit(int cr
, int bit
)
564 struct ec_creg_mask_parms parms
= { 0, ~(1UL << bit
), cr
};
566 on_each_cpu(smp_ctl_bit_callback
, &parms
, 1);
568 EXPORT_SYMBOL(smp_ctl_clear_bit
);
570 #ifdef CONFIG_CRASH_DUMP
572 int smp_store_status(int cpu
)
574 struct pcpu
*pcpu
= pcpu_devices
+ cpu
;
577 pa
= __pa(&pcpu
->lowcore
->floating_pt_save_area
);
578 if (__pcpu_sigp_relax(pcpu
->address
, SIGP_STORE_STATUS_AT_ADDRESS
,
579 pa
) != SIGP_CC_ORDER_CODE_ACCEPTED
)
581 if (!MACHINE_HAS_VX
&& !MACHINE_HAS_GS
)
583 pa
= __pa(pcpu
->lowcore
->mcesad
& MCESA_ORIGIN_MASK
);
585 pa
|= pcpu
->lowcore
->mcesad
& MCESA_LC_MASK
;
586 if (__pcpu_sigp_relax(pcpu
->address
, SIGP_STORE_ADDITIONAL_STATUS
,
587 pa
) != SIGP_CC_ORDER_CODE_ACCEPTED
)
593 * Collect CPU state of the previous, crashed system.
594 * There are four cases:
595 * 1) standard zfcp dump
596 * condition: OLDMEM_BASE == NULL && ipl_info.type == IPL_TYPE_FCP_DUMP
597 * The state for all CPUs except the boot CPU needs to be collected
598 * with sigp stop-and-store-status. The boot CPU state is located in
599 * the absolute lowcore of the memory stored in the HSA. The zcore code
600 * will copy the boot CPU state from the HSA.
601 * 2) stand-alone kdump for SCSI (zfcp dump with swapped memory)
602 * condition: OLDMEM_BASE != NULL && ipl_info.type == IPL_TYPE_FCP_DUMP
603 * The state for all CPUs except the boot CPU needs to be collected
604 * with sigp stop-and-store-status. The firmware or the boot-loader
605 * stored the registers of the boot CPU in the absolute lowcore in the
606 * memory of the old system.
607 * 3) kdump and the old kernel did not store the CPU state,
608 * or stand-alone kdump for DASD
609 * condition: OLDMEM_BASE != NULL && !is_kdump_kernel()
610 * The state for all CPUs except the boot CPU needs to be collected
611 * with sigp stop-and-store-status. The kexec code or the boot-loader
612 * stored the registers of the boot CPU in the memory of the old system.
613 * 4) kdump and the old kernel stored the CPU state
614 * condition: OLDMEM_BASE != NULL && is_kdump_kernel()
615 * This case does not exist for s390 anymore, setup_arch explicitly
616 * deactivates the elfcorehdr= kernel parameter
618 static __init
void smp_save_cpu_vxrs(struct save_area
*sa
, u16 addr
,
619 bool is_boot_cpu
, unsigned long page
)
621 __vector128
*vxrs
= (__vector128
*) page
;
624 vxrs
= boot_cpu_vector_save_area
;
626 __pcpu_sigp_relax(addr
, SIGP_STORE_ADDITIONAL_STATUS
, page
);
627 save_area_add_vxrs(sa
, vxrs
);
630 static __init
void smp_save_cpu_regs(struct save_area
*sa
, u16 addr
,
631 bool is_boot_cpu
, unsigned long page
)
633 void *regs
= (void *) page
;
636 copy_oldmem_kernel(regs
, (void *) __LC_FPREGS_SAVE_AREA
, 512);
638 __pcpu_sigp_relax(addr
, SIGP_STORE_STATUS_AT_ADDRESS
, page
);
639 save_area_add_regs(sa
, regs
);
642 void __init
smp_save_dump_cpus(void)
644 int addr
, boot_cpu_addr
, max_cpu_addr
;
645 struct save_area
*sa
;
649 if (!(OLDMEM_BASE
|| ipl_info
.type
== IPL_TYPE_FCP_DUMP
))
650 /* No previous system present, normal boot. */
652 /* Allocate a page as dumping area for the store status sigps */
653 page
= memblock_alloc_base(PAGE_SIZE
, PAGE_SIZE
, 1UL << 31);
654 /* Set multi-threading state to the previous system. */
655 pcpu_set_smt(sclp
.mtid_prev
);
656 boot_cpu_addr
= stap();
657 max_cpu_addr
= SCLP_MAX_CORES
<< sclp
.mtid_prev
;
658 for (addr
= 0; addr
<= max_cpu_addr
; addr
++) {
659 if (__pcpu_sigp_relax(addr
, SIGP_SENSE
, 0) ==
660 SIGP_CC_NOT_OPERATIONAL
)
662 is_boot_cpu
= (addr
== boot_cpu_addr
);
663 /* Allocate save area */
664 sa
= save_area_alloc(is_boot_cpu
);
666 panic("could not allocate memory for save area\n");
668 /* Get the vector registers */
669 smp_save_cpu_vxrs(sa
, addr
, is_boot_cpu
, page
);
671 * For a zfcp dump OLDMEM_BASE == NULL and the registers
672 * of the boot CPU are stored in the HSA. To retrieve
673 * these registers an SCLP request is required which is
674 * done by drivers/s390/char/zcore.c:init_cpu_info()
676 if (!is_boot_cpu
|| OLDMEM_BASE
)
677 /* Get the CPU registers */
678 smp_save_cpu_regs(sa
, addr
, is_boot_cpu
, page
);
680 memblock_free(page
, PAGE_SIZE
);
684 #endif /* CONFIG_CRASH_DUMP */
686 void smp_cpu_set_polarization(int cpu
, int val
)
688 pcpu_devices
[cpu
].polarization
= val
;
691 int smp_cpu_get_polarization(int cpu
)
693 return pcpu_devices
[cpu
].polarization
;
696 static void __ref
smp_get_core_info(struct sclp_core_info
*info
, int early
)
698 static int use_sigp_detection
;
701 if (use_sigp_detection
|| sclp_get_core_info(info
, early
)) {
702 use_sigp_detection
= 1;
704 address
< (SCLP_MAX_CORES
<< smp_cpu_mt_shift
);
705 address
+= (1U << smp_cpu_mt_shift
)) {
706 if (__pcpu_sigp_relax(address
, SIGP_SENSE
, 0) ==
707 SIGP_CC_NOT_OPERATIONAL
)
709 info
->core
[info
->configured
].core_id
=
710 address
>> smp_cpu_mt_shift
;
713 info
->combined
= info
->configured
;
717 static int smp_add_present_cpu(int cpu
);
719 static int __smp_rescan_cpus(struct sclp_core_info
*info
, int sysfs_add
)
727 cpumask_xor(&avail
, cpu_possible_mask
, cpu_present_mask
);
728 cpu
= cpumask_first(&avail
);
729 for (i
= 0; (i
< info
->combined
) && (cpu
< nr_cpu_ids
); i
++) {
730 if (sclp
.has_core_type
&& info
->core
[i
].type
!= boot_core_type
)
732 address
= info
->core
[i
].core_id
<< smp_cpu_mt_shift
;
733 for (j
= 0; j
<= smp_cpu_mtid
; j
++) {
734 if (pcpu_find_address(cpu_present_mask
, address
+ j
))
736 pcpu
= pcpu_devices
+ cpu
;
737 pcpu
->address
= address
+ j
;
739 (cpu
>= info
->configured
*(smp_cpu_mtid
+ 1)) ?
740 CPU_STATE_STANDBY
: CPU_STATE_CONFIGURED
;
741 smp_cpu_set_polarization(cpu
, POLARIZATION_UNKNOWN
);
742 set_cpu_present(cpu
, true);
743 if (sysfs_add
&& smp_add_present_cpu(cpu
) != 0)
744 set_cpu_present(cpu
, false);
747 cpu
= cpumask_next(cpu
, &avail
);
748 if (cpu
>= nr_cpu_ids
)
755 void __init
smp_detect_cpus(void)
757 unsigned int cpu
, mtid
, c_cpus
, s_cpus
;
758 struct sclp_core_info
*info
;
761 /* Get CPU information */
762 info
= memblock_virt_alloc(sizeof(*info
), 8);
763 smp_get_core_info(info
, 1);
764 /* Find boot CPU type */
765 if (sclp
.has_core_type
) {
767 for (cpu
= 0; cpu
< info
->combined
; cpu
++)
768 if (info
->core
[cpu
].core_id
== address
) {
769 /* The boot cpu dictates the cpu type. */
770 boot_core_type
= info
->core
[cpu
].type
;
773 if (cpu
>= info
->combined
)
774 panic("Could not find boot CPU type");
777 /* Set multi-threading state for the current system */
778 mtid
= boot_core_type
? sclp
.mtid
: sclp
.mtid_cp
;
779 mtid
= (mtid
< smp_max_threads
) ? mtid
: smp_max_threads
- 1;
782 /* Print number of CPUs */
784 for (cpu
= 0; cpu
< info
->combined
; cpu
++) {
785 if (sclp
.has_core_type
&&
786 info
->core
[cpu
].type
!= boot_core_type
)
788 if (cpu
< info
->configured
)
789 c_cpus
+= smp_cpu_mtid
+ 1;
791 s_cpus
+= smp_cpu_mtid
+ 1;
793 pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus
, s_cpus
);
795 /* Add CPUs present at boot */
797 __smp_rescan_cpus(info
, 0);
799 memblock_free_early((unsigned long)info
, sizeof(*info
));
803 * Activate a secondary processor.
805 static void smp_start_secondary(void *cpuvoid
)
807 int cpu
= smp_processor_id();
809 S390_lowcore
.last_update_clock
= get_tod_clock();
810 S390_lowcore
.restart_stack
= (unsigned long) restart_stack
;
811 S390_lowcore
.restart_fn
= (unsigned long) do_restart
;
812 S390_lowcore
.restart_data
= 0;
813 S390_lowcore
.restart_source
= -1UL;
814 restore_access_regs(S390_lowcore
.access_regs_save_area
);
815 __ctl_load(S390_lowcore
.cregs_save_area
, 0, 15);
816 __load_psw_mask(PSW_KERNEL_BITS
| PSW_MASK_DAT
);
817 set_cpu_flag(CIF_ASCE_PRIMARY
);
818 set_cpu_flag(CIF_ASCE_SECONDARY
);
824 notify_cpu_starting(cpu
);
825 if (topology_cpu_dedicated(cpu
))
826 set_cpu_flag(CIF_DEDICATED_CPU
);
828 clear_cpu_flag(CIF_DEDICATED_CPU
);
829 set_cpu_online(cpu
, true);
830 inc_irq_stat(CPU_RST
);
832 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE
);
835 /* Upping and downing of CPUs */
836 int __cpu_up(unsigned int cpu
, struct task_struct
*tidle
)
841 pcpu
= pcpu_devices
+ cpu
;
842 if (pcpu
->state
!= CPU_STATE_CONFIGURED
)
844 base
= smp_get_base_cpu(cpu
);
845 for (i
= 0; i
<= smp_cpu_mtid
; i
++) {
846 if (base
+ i
< nr_cpu_ids
)
847 if (cpu_online(base
+ i
))
851 * If this is the first CPU of the core to get online
852 * do an initial CPU reset.
854 if (i
> smp_cpu_mtid
&&
855 pcpu_sigp_retry(pcpu_devices
+ base
, SIGP_INITIAL_CPU_RESET
, 0) !=
856 SIGP_CC_ORDER_CODE_ACCEPTED
)
859 rc
= pcpu_alloc_lowcore(pcpu
, cpu
);
862 pcpu_prepare_secondary(pcpu
, cpu
);
863 pcpu_attach_task(pcpu
, tidle
);
864 pcpu_start_fn(pcpu
, smp_start_secondary
, NULL
);
865 /* Wait until cpu puts itself in the online & active maps */
866 while (!cpu_online(cpu
))
871 static unsigned int setup_possible_cpus __initdata
;
873 static int __init
_setup_possible_cpus(char *s
)
875 get_option(&s
, &setup_possible_cpus
);
878 early_param("possible_cpus", _setup_possible_cpus
);
880 #ifdef CONFIG_HOTPLUG_CPU
882 int __cpu_disable(void)
884 unsigned long cregs
[16];
886 /* Handle possible pending IPIs */
887 smp_handle_ext_call();
888 set_cpu_online(smp_processor_id(), false);
889 /* Disable pseudo page faults on this cpu. */
891 /* Disable interrupt sources via control register. */
892 __ctl_store(cregs
, 0, 15);
893 cregs
[0] &= ~0x0000ee70UL
; /* disable all external interrupts */
894 cregs
[6] &= ~0xff000000UL
; /* disable all I/O interrupts */
895 cregs
[14] &= ~0x1f000000UL
; /* disable most machine checks */
896 __ctl_load(cregs
, 0, 15);
897 clear_cpu_flag(CIF_NOHZ_DELAY
);
901 void __cpu_die(unsigned int cpu
)
905 /* Wait until target cpu is down */
906 pcpu
= pcpu_devices
+ cpu
;
907 while (!pcpu_stopped(pcpu
))
909 pcpu_free_lowcore(pcpu
);
910 cpumask_clear_cpu(cpu
, mm_cpumask(&init_mm
));
911 cpumask_clear_cpu(cpu
, &init_mm
.context
.cpu_attach_mask
);
914 void __noreturn
cpu_die(void)
918 pcpu_sigp_retry(pcpu_devices
+ smp_processor_id(), SIGP_STOP
, 0);
922 #endif /* CONFIG_HOTPLUG_CPU */
924 void __init
smp_fill_possible_mask(void)
926 unsigned int possible
, sclp_max
, cpu
;
928 sclp_max
= max(sclp
.mtid
, sclp
.mtid_cp
) + 1;
929 sclp_max
= min(smp_max_threads
, sclp_max
);
930 sclp_max
= (sclp
.max_cores
* sclp_max
) ?: nr_cpu_ids
;
931 possible
= setup_possible_cpus
?: nr_cpu_ids
;
932 possible
= min(possible
, sclp_max
);
933 for (cpu
= 0; cpu
< possible
&& cpu
< nr_cpu_ids
; cpu
++)
934 set_cpu_possible(cpu
, true);
937 void __init
smp_prepare_cpus(unsigned int max_cpus
)
939 /* request the 0x1201 emergency signal external interrupt */
940 if (register_external_irq(EXT_IRQ_EMERGENCY_SIG
, do_ext_call_interrupt
))
941 panic("Couldn't request external interrupt 0x1201");
942 /* request the 0x1202 external call external interrupt */
943 if (register_external_irq(EXT_IRQ_EXTERNAL_CALL
, do_ext_call_interrupt
))
944 panic("Couldn't request external interrupt 0x1202");
947 void __init
smp_prepare_boot_cpu(void)
949 struct pcpu
*pcpu
= pcpu_devices
;
951 WARN_ON(!cpu_present(0) || !cpu_online(0));
952 pcpu
->state
= CPU_STATE_CONFIGURED
;
953 pcpu
->lowcore
= (struct lowcore
*)(unsigned long) store_prefix();
954 S390_lowcore
.percpu_offset
= __per_cpu_offset
[0];
955 smp_cpu_set_polarization(0, POLARIZATION_UNKNOWN
);
958 void __init
smp_cpus_done(unsigned int max_cpus
)
962 void __init
smp_setup_processor_id(void)
964 pcpu_devices
[0].address
= stap();
965 S390_lowcore
.cpu_nr
= 0;
966 S390_lowcore
.spinlock_lockval
= arch_spin_lockval(0);
967 S390_lowcore
.spinlock_index
= 0;
971 * the frequency of the profiling timer can be changed
972 * by writing a multiplier value into /proc/profile.
974 * usually you want to run this on all CPUs ;)
976 int setup_profiling_timer(unsigned int multiplier
)
981 #ifdef CONFIG_HOTPLUG_CPU
982 static ssize_t
cpu_configure_show(struct device
*dev
,
983 struct device_attribute
*attr
, char *buf
)
987 mutex_lock(&smp_cpu_state_mutex
);
988 count
= sprintf(buf
, "%d\n", pcpu_devices
[dev
->id
].state
);
989 mutex_unlock(&smp_cpu_state_mutex
);
993 static ssize_t
cpu_configure_store(struct device
*dev
,
994 struct device_attribute
*attr
,
995 const char *buf
, size_t count
)
1001 if (sscanf(buf
, "%d %c", &val
, &delim
) != 1)
1003 if (val
!= 0 && val
!= 1)
1006 mutex_lock(&smp_cpu_state_mutex
);
1008 /* disallow configuration changes of online cpus and cpu 0 */
1010 cpu
= smp_get_base_cpu(cpu
);
1013 for (i
= 0; i
<= smp_cpu_mtid
; i
++)
1014 if (cpu_online(cpu
+ i
))
1016 pcpu
= pcpu_devices
+ cpu
;
1020 if (pcpu
->state
!= CPU_STATE_CONFIGURED
)
1022 rc
= sclp_core_deconfigure(pcpu
->address
>> smp_cpu_mt_shift
);
1025 for (i
= 0; i
<= smp_cpu_mtid
; i
++) {
1026 if (cpu
+ i
>= nr_cpu_ids
|| !cpu_present(cpu
+ i
))
1028 pcpu
[i
].state
= CPU_STATE_STANDBY
;
1029 smp_cpu_set_polarization(cpu
+ i
,
1030 POLARIZATION_UNKNOWN
);
1032 topology_expect_change();
1035 if (pcpu
->state
!= CPU_STATE_STANDBY
)
1037 rc
= sclp_core_configure(pcpu
->address
>> smp_cpu_mt_shift
);
1040 for (i
= 0; i
<= smp_cpu_mtid
; i
++) {
1041 if (cpu
+ i
>= nr_cpu_ids
|| !cpu_present(cpu
+ i
))
1043 pcpu
[i
].state
= CPU_STATE_CONFIGURED
;
1044 smp_cpu_set_polarization(cpu
+ i
,
1045 POLARIZATION_UNKNOWN
);
1047 topology_expect_change();
1053 mutex_unlock(&smp_cpu_state_mutex
);
1055 return rc
? rc
: count
;
1057 static DEVICE_ATTR(configure
, 0644, cpu_configure_show
, cpu_configure_store
);
1058 #endif /* CONFIG_HOTPLUG_CPU */
1060 static ssize_t
show_cpu_address(struct device
*dev
,
1061 struct device_attribute
*attr
, char *buf
)
1063 return sprintf(buf
, "%d\n", pcpu_devices
[dev
->id
].address
);
1065 static DEVICE_ATTR(address
, 0444, show_cpu_address
, NULL
);
1067 static struct attribute
*cpu_common_attrs
[] = {
1068 #ifdef CONFIG_HOTPLUG_CPU
1069 &dev_attr_configure
.attr
,
1071 &dev_attr_address
.attr
,
1075 static struct attribute_group cpu_common_attr_group
= {
1076 .attrs
= cpu_common_attrs
,
1079 static struct attribute
*cpu_online_attrs
[] = {
1080 &dev_attr_idle_count
.attr
,
1081 &dev_attr_idle_time_us
.attr
,
1085 static struct attribute_group cpu_online_attr_group
= {
1086 .attrs
= cpu_online_attrs
,
1089 static int smp_cpu_online(unsigned int cpu
)
1091 struct device
*s
= &per_cpu(cpu_device
, cpu
)->dev
;
1093 return sysfs_create_group(&s
->kobj
, &cpu_online_attr_group
);
1095 static int smp_cpu_pre_down(unsigned int cpu
)
1097 struct device
*s
= &per_cpu(cpu_device
, cpu
)->dev
;
1099 sysfs_remove_group(&s
->kobj
, &cpu_online_attr_group
);
1103 static int smp_add_present_cpu(int cpu
)
1109 c
= kzalloc(sizeof(*c
), GFP_KERNEL
);
1112 per_cpu(cpu_device
, cpu
) = c
;
1114 c
->hotpluggable
= 1;
1115 rc
= register_cpu(c
, cpu
);
1118 rc
= sysfs_create_group(&s
->kobj
, &cpu_common_attr_group
);
1121 rc
= topology_cpu_init(c
);
1127 sysfs_remove_group(&s
->kobj
, &cpu_common_attr_group
);
1129 #ifdef CONFIG_HOTPLUG_CPU
1136 #ifdef CONFIG_HOTPLUG_CPU
1138 int __ref
smp_rescan_cpus(void)
1140 struct sclp_core_info
*info
;
1143 info
= kzalloc(sizeof(*info
), GFP_KERNEL
);
1146 smp_get_core_info(info
, 0);
1148 mutex_lock(&smp_cpu_state_mutex
);
1149 nr
= __smp_rescan_cpus(info
, 1);
1150 mutex_unlock(&smp_cpu_state_mutex
);
1154 topology_schedule_update();
1158 static ssize_t __ref
rescan_store(struct device
*dev
,
1159 struct device_attribute
*attr
,
1165 rc
= lock_device_hotplug_sysfs();
1168 rc
= smp_rescan_cpus();
1169 unlock_device_hotplug();
1170 return rc
? rc
: count
;
1172 static DEVICE_ATTR_WO(rescan
);
1173 #endif /* CONFIG_HOTPLUG_CPU */
1175 static int __init
s390_smp_init(void)
1179 #ifdef CONFIG_HOTPLUG_CPU
1180 rc
= device_create_file(cpu_subsys
.dev_root
, &dev_attr_rescan
);
1184 for_each_present_cpu(cpu
) {
1185 rc
= smp_add_present_cpu(cpu
);
1190 rc
= cpuhp_setup_state(CPUHP_AP_ONLINE_DYN
, "s390/smp:online",
1191 smp_cpu_online
, smp_cpu_pre_down
);
1192 rc
= rc
<= 0 ? rc
: 0;
1196 subsys_initcall(s390_smp_init
);