2 * arch/s390/kernel/smp.c
4 * Copyright (C) IBM Corp. 1999,2006
5 * Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
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 * We work with logical cpu numbering everywhere we can. The only
14 * functions using the real cpu address (got from STAP) are the sigp
15 * functions. For all other functions we use the identity mapping.
16 * That means that cpu_number_map[i] == i for every cpu. cpu_number_map is
17 * used e.g. to find the idle task belonging to a logical cpu. Every array
18 * in the kernel is sorted by the logical cpu number and not by the physical
19 * one which is causing all the confusion with __cpu_logical_map and
20 * cpu_number_map in other architectures.
23 #include <linux/module.h>
24 #include <linux/init.h>
27 #include <linux/spinlock.h>
28 #include <linux/kernel_stat.h>
29 #include <linux/smp_lock.h>
31 #include <linux/delay.h>
32 #include <linux/cache.h>
33 #include <linux/interrupt.h>
34 #include <linux/cpu.h>
37 #include <asm/pgalloc.h>
39 #include <asm/s390_ext.h>
40 #include <asm/cpcmd.h>
41 #include <asm/tlbflush.h>
43 extern volatile int __cpu_logical_map
[];
46 * An array with a pointer the lowcore of every CPU.
49 struct _lowcore
*lowcore_ptr
[NR_CPUS
];
51 cpumask_t cpu_online_map
= CPU_MASK_NONE
;
52 cpumask_t cpu_possible_map
= CPU_MASK_NONE
;
54 static struct task_struct
*current_set
[NR_CPUS
];
57 * Reboot, halt and power_off routines for SMP.
59 extern char vmhalt_cmd
[];
60 extern char vmpoff_cmd
[];
62 extern void reipl(unsigned long devno
);
63 extern void reipl_diag(void);
65 static void smp_ext_bitcall(int, ec_bit_sig
);
66 static void smp_ext_bitcall_others(ec_bit_sig
);
69 * Structure and data for smp_call_function(). This is designed to minimise
70 * static memory requirements. It also looks cleaner.
72 static DEFINE_SPINLOCK(call_lock
);
74 struct call_data_struct
{
75 void (*func
) (void *info
);
82 static struct call_data_struct
* call_data
;
85 * 'Call function' interrupt callback
87 static void do_call_function(void)
89 void (*func
) (void *info
) = call_data
->func
;
90 void *info
= call_data
->info
;
91 int wait
= call_data
->wait
;
93 atomic_inc(&call_data
->started
);
96 atomic_inc(&call_data
->finished
);
100 * this function sends a 'generic call function' IPI to all other CPUs
104 int smp_call_function (void (*func
) (void *info
), void *info
, int nonatomic
,
107 * [SUMMARY] Run a function on all other CPUs.
108 * <func> The function to run. This must be fast and non-blocking.
109 * <info> An arbitrary pointer to pass to the function.
110 * <nonatomic> currently unused.
111 * <wait> If true, wait (atomically) until function has completed on other CPUs.
112 * [RETURNS] 0 on success, else a negative status code. Does not return until
113 * remote CPUs are nearly ready to execute <<func>> or are or have executed.
115 * You must not call this function with disabled interrupts or from a
116 * hardware interrupt handler or from a bottom half handler.
119 struct call_data_struct data
;
120 int cpus
= num_online_cpus()-1;
125 /* Can deadlock when called with interrupts disabled */
126 WARN_ON(irqs_disabled());
130 atomic_set(&data
.started
, 0);
133 atomic_set(&data
.finished
, 0);
135 spin_lock(&call_lock
);
137 /* Send a message to all other CPUs and wait for them to respond */
138 smp_ext_bitcall_others(ec_call_function
);
140 /* Wait for response */
141 while (atomic_read(&data
.started
) != cpus
)
145 while (atomic_read(&data
.finished
) != cpus
)
147 spin_unlock(&call_lock
);
153 * Call a function on one CPU
154 * cpu : the CPU the function should be executed on
156 * You must not call this function with disabled interrupts or from a
157 * hardware interrupt handler. You may call it from a bottom half.
159 * It is guaranteed that the called function runs on the specified CPU,
160 * preemption is disabled.
162 int smp_call_function_on(void (*func
) (void *info
), void *info
,
163 int nonatomic
, int wait
, int cpu
)
165 struct call_data_struct data
;
168 if (!cpu_online(cpu
))
171 /* disable preemption for local function call */
172 curr_cpu
= get_cpu();
174 if (curr_cpu
== cpu
) {
175 /* direct call to function */
183 atomic_set(&data
.started
, 0);
186 atomic_set(&data
.finished
, 0);
188 spin_lock_bh(&call_lock
);
190 smp_ext_bitcall(cpu
, ec_call_function
);
192 /* Wait for response */
193 while (atomic_read(&data
.started
) != 1)
197 while (atomic_read(&data
.finished
) != 1)
200 spin_unlock_bh(&call_lock
);
204 EXPORT_SYMBOL(smp_call_function_on
);
206 static inline void do_send_stop(void)
210 /* stop all processors */
211 for_each_online_cpu(cpu
) {
212 if (cpu
== smp_processor_id())
215 rc
= signal_processor(cpu
, sigp_stop
);
216 } while (rc
== sigp_busy
);
220 static inline void do_store_status(void)
224 /* store status of all processors in their lowcores (real 0) */
225 for_each_online_cpu(cpu
) {
226 if (cpu
== smp_processor_id())
229 rc
= signal_processor_p(
230 (__u32
)(unsigned long) lowcore_ptr
[cpu
], cpu
,
231 sigp_store_status_at_address
);
232 } while(rc
== sigp_busy
);
237 * this function sends a 'stop' sigp to all other CPUs in the system.
238 * it goes straight through.
240 void smp_send_stop(void)
242 /* write magic number to zero page (absolute 0) */
243 lowcore_ptr
[smp_processor_id()]->panic_magic
= __PANIC_MAGIC
;
245 /* stop other processors. */
248 /* store status of other processors. */
253 * Reboot, halt and power_off routines for SMP.
256 static void do_machine_restart(void * __unused
)
259 static atomic_t cpuid
= ATOMIC_INIT(-1);
261 if (atomic_cmpxchg(&cpuid
, -1, smp_processor_id()) != -1)
262 signal_processor(smp_processor_id(), sigp_stop
);
264 /* Wait for all other cpus to enter stopped state */
265 for_each_online_cpu(cpu
) {
266 if (cpu
== smp_processor_id())
268 while(!smp_cpu_not_running(cpu
))
272 /* Store status of other cpus. */
276 * Finally call reipl. Because we waited for all other
277 * cpus to enter this function we know that they do
278 * not hold any s390irq-locks (the cpus have been
279 * interrupted by an external interrupt and s390irq
280 * locks are always held disabled).
285 cpcmd ("IPL", NULL
, 0, NULL
);
287 reipl (0x10000 | S390_lowcore
.ipl_device
);
290 void machine_restart_smp(char * __unused
)
292 on_each_cpu(do_machine_restart
, NULL
, 0, 0);
295 static void do_wait_for_stop(void)
297 unsigned long cr
[16];
299 __ctl_store(cr
, 0, 15);
302 __ctl_load(cr
, 0, 15);
307 static void do_machine_halt(void * __unused
)
309 static atomic_t cpuid
= ATOMIC_INIT(-1);
311 if (atomic_cmpxchg(&cpuid
, -1, smp_processor_id()) == -1) {
313 if (MACHINE_IS_VM
&& strlen(vmhalt_cmd
) > 0)
314 cpcmd(vmhalt_cmd
, NULL
, 0, NULL
);
315 signal_processor(smp_processor_id(),
316 sigp_stop_and_store_status
);
321 void machine_halt_smp(void)
323 on_each_cpu(do_machine_halt
, NULL
, 0, 0);
326 static void do_machine_power_off(void * __unused
)
328 static atomic_t cpuid
= ATOMIC_INIT(-1);
330 if (atomic_cmpxchg(&cpuid
, -1, smp_processor_id()) == -1) {
332 if (MACHINE_IS_VM
&& strlen(vmpoff_cmd
) > 0)
333 cpcmd(vmpoff_cmd
, NULL
, 0, NULL
);
334 signal_processor(smp_processor_id(),
335 sigp_stop_and_store_status
);
340 void machine_power_off_smp(void)
342 on_each_cpu(do_machine_power_off
, NULL
, 0, 0);
346 * This is the main routine where commands issued by other
350 void do_ext_call_interrupt(struct pt_regs
*regs
, __u16 code
)
355 * handle bit signal external calls
357 * For the ec_schedule signal we have to do nothing. All the work
358 * is done automatically when we return from the interrupt.
360 bits
= xchg(&S390_lowcore
.ext_call_fast
, 0);
362 if (test_bit(ec_call_function
, &bits
))
367 * Send an external call sigp to another cpu and return without waiting
368 * for its completion.
370 static void smp_ext_bitcall(int cpu
, ec_bit_sig sig
)
373 * Set signaling bit in lowcore of target cpu and kick it
375 set_bit(sig
, (unsigned long *) &lowcore_ptr
[cpu
]->ext_call_fast
);
376 while(signal_processor(cpu
, sigp_emergency_signal
) == sigp_busy
)
381 * Send an external call sigp to every other cpu in the system and
382 * return without waiting for its completion.
384 static void smp_ext_bitcall_others(ec_bit_sig sig
)
388 for_each_online_cpu(cpu
) {
389 if (cpu
== smp_processor_id())
392 * Set signaling bit in lowcore of target cpu and kick it
394 set_bit(sig
, (unsigned long *) &lowcore_ptr
[cpu
]->ext_call_fast
);
395 while (signal_processor(cpu
, sigp_emergency_signal
) == sigp_busy
)
402 * this function sends a 'purge tlb' signal to another CPU.
404 void smp_ptlb_callback(void *info
)
409 void smp_ptlb_all(void)
411 on_each_cpu(smp_ptlb_callback
, NULL
, 0, 1);
413 EXPORT_SYMBOL(smp_ptlb_all
);
414 #endif /* ! CONFIG_64BIT */
417 * this function sends a 'reschedule' IPI to another CPU.
418 * it goes straight through and wastes no time serializing
419 * anything. Worst case is that we lose a reschedule ...
421 void smp_send_reschedule(int cpu
)
423 smp_ext_bitcall(cpu
, ec_schedule
);
427 * parameter area for the set/clear control bit callbacks
433 unsigned long orvals
[16];
434 unsigned long andvals
[16];
435 } ec_creg_mask_parms
;
438 * callback for setting/clearing control bits
440 void smp_ctl_bit_callback(void *info
) {
441 ec_creg_mask_parms
*pp
;
442 unsigned long cregs
[16];
445 pp
= (ec_creg_mask_parms
*) info
;
446 __ctl_store(cregs
[pp
->start_ctl
], pp
->start_ctl
, pp
->end_ctl
);
447 for (i
= pp
->start_ctl
; i
<= pp
->end_ctl
; i
++)
448 cregs
[i
] = (cregs
[i
] & pp
->andvals
[i
]) | pp
->orvals
[i
];
449 __ctl_load(cregs
[pp
->start_ctl
], pp
->start_ctl
, pp
->end_ctl
);
453 * Set a bit in a control register of all cpus
455 void smp_ctl_set_bit(int cr
, int bit
) {
456 ec_creg_mask_parms parms
;
458 parms
.start_ctl
= cr
;
460 parms
.orvals
[cr
] = 1 << bit
;
461 parms
.andvals
[cr
] = -1L;
463 smp_call_function(smp_ctl_bit_callback
, &parms
, 0, 1);
464 __ctl_set_bit(cr
, bit
);
469 * Clear a bit in a control register of all cpus
471 void smp_ctl_clear_bit(int cr
, int bit
) {
472 ec_creg_mask_parms parms
;
474 parms
.start_ctl
= cr
;
476 parms
.orvals
[cr
] = 0;
477 parms
.andvals
[cr
] = ~(1L << bit
);
479 smp_call_function(smp_ctl_bit_callback
, &parms
, 0, 1);
480 __ctl_clear_bit(cr
, bit
);
485 * Lets check how many CPUs we have.
489 __init
smp_count_cpus(void)
491 unsigned int cpu
, num_cpus
;
495 * cpu 0 is the boot cpu. See smp_prepare_boot_cpu.
498 boot_cpu_addr
= S390_lowcore
.cpu_data
.cpu_addr
;
499 current_thread_info()->cpu
= 0;
501 for (cpu
= 0; cpu
<= 65535; cpu
++) {
502 if ((__u16
) cpu
== boot_cpu_addr
)
504 __cpu_logical_map
[1] = (__u16
) cpu
;
505 if (signal_processor(1, sigp_sense
) ==
506 sigp_not_operational
)
511 printk("Detected %d CPU's\n",(int) num_cpus
);
512 printk("Boot cpu address %2X\n", boot_cpu_addr
);
518 * Activate a secondary processor.
520 extern void init_cpu_timer(void);
521 extern void init_cpu_vtimer(void);
522 extern int pfault_init(void);
523 extern void pfault_fini(void);
525 int __devinit
start_secondary(void *cpuvoid
)
530 /* init per CPU timer */
532 #ifdef CONFIG_VIRT_TIMER
536 /* Enable pfault pseudo page faults on this cpu. */
540 /* Mark this cpu as online */
541 cpu_set(smp_processor_id(), cpu_online_map
);
542 /* Switch on interrupts */
544 /* Print info about this processor */
545 print_cpu_info(&S390_lowcore
.cpu_data
);
546 /* cpu_idle will call schedule for us */
551 static void __init
smp_create_idle(unsigned int cpu
)
553 struct task_struct
*p
;
556 * don't care about the psw and regs settings since we'll never
557 * reschedule the forked task.
561 panic("failed fork for CPU %u: %li", cpu
, PTR_ERR(p
));
562 current_set
[cpu
] = p
;
565 /* Reserving and releasing of CPUs */
567 static DEFINE_SPINLOCK(smp_reserve_lock
);
568 static int smp_cpu_reserved
[NR_CPUS
];
571 smp_get_cpu(cpumask_t cpu_mask
)
576 spin_lock_irqsave(&smp_reserve_lock
, flags
);
577 /* Try to find an already reserved cpu. */
578 for_each_cpu_mask(cpu
, cpu_mask
) {
579 if (smp_cpu_reserved
[cpu
] != 0) {
580 smp_cpu_reserved
[cpu
]++;
585 /* Reserve a new cpu from cpu_mask. */
586 for_each_cpu_mask(cpu
, cpu_mask
) {
587 if (cpu_online(cpu
)) {
588 smp_cpu_reserved
[cpu
]++;
594 spin_unlock_irqrestore(&smp_reserve_lock
, flags
);
603 spin_lock_irqsave(&smp_reserve_lock
, flags
);
604 smp_cpu_reserved
[cpu
]--;
605 spin_unlock_irqrestore(&smp_reserve_lock
, flags
);
613 /* Check for stopped state */
614 if (signal_processor_ps(&status
, 0, cpu
, sigp_sense
) == sigp_status_stored
) {
621 /* Upping and downing of CPUs */
624 __cpu_up(unsigned int cpu
)
626 struct task_struct
*idle
;
627 struct _lowcore
*cpu_lowcore
;
628 struct stack_frame
*sf
;
632 for (curr_cpu
= 0; curr_cpu
<= 65535; curr_cpu
++) {
633 __cpu_logical_map
[cpu
] = (__u16
) curr_cpu
;
634 if (cpu_stopped(cpu
))
638 if (!cpu_stopped(cpu
))
641 ccode
= signal_processor_p((__u32
)(unsigned long)(lowcore_ptr
[cpu
]),
642 cpu
, sigp_set_prefix
);
644 printk("sigp_set_prefix failed for cpu %d "
645 "with condition code %d\n",
646 (int) cpu
, (int) ccode
);
650 idle
= current_set
[cpu
];
651 cpu_lowcore
= lowcore_ptr
[cpu
];
652 cpu_lowcore
->kernel_stack
= (unsigned long)
653 task_stack_page(idle
) + (THREAD_SIZE
);
654 sf
= (struct stack_frame
*) (cpu_lowcore
->kernel_stack
655 - sizeof(struct pt_regs
)
656 - sizeof(struct stack_frame
));
657 memset(sf
, 0, sizeof(struct stack_frame
));
658 sf
->gprs
[9] = (unsigned long) sf
;
659 cpu_lowcore
->save_area
[15] = (unsigned long) sf
;
660 __ctl_store(cpu_lowcore
->cregs_save_area
[0], 0, 15);
661 __asm__
__volatile__("stam 0,15,0(%0)"
662 : : "a" (&cpu_lowcore
->access_regs_save_area
)
664 cpu_lowcore
->percpu_offset
= __per_cpu_offset
[cpu
];
665 cpu_lowcore
->current_task
= (unsigned long) idle
;
666 cpu_lowcore
->cpu_data
.cpu_nr
= cpu
;
668 signal_processor(cpu
,sigp_restart
);
670 while (!cpu_online(cpu
))
675 static unsigned int __initdata additional_cpus
;
677 void __init
smp_setup_cpu_possible_map(void)
679 unsigned int pcpus
, cpu
;
681 pcpus
= smp_count_cpus() + additional_cpus
;
686 for (cpu
= 0; cpu
< pcpus
; cpu
++)
687 cpu_set(cpu
, cpu_possible_map
);
689 cpu_present_map
= cpu_possible_map
;
692 #ifdef CONFIG_HOTPLUG_CPU
694 static int __init
setup_additional_cpus(char *s
)
696 additional_cpus
= simple_strtoul(s
, NULL
, 0);
699 early_param("additional_cpus", setup_additional_cpus
);
705 ec_creg_mask_parms cr_parms
;
706 int cpu
= smp_processor_id();
708 spin_lock_irqsave(&smp_reserve_lock
, flags
);
709 if (smp_cpu_reserved
[cpu
] != 0) {
710 spin_unlock_irqrestore(&smp_reserve_lock
, flags
);
713 cpu_clear(cpu
, cpu_online_map
);
716 /* Disable pfault pseudo page faults on this cpu. */
721 /* disable all external interrupts */
723 cr_parms
.start_ctl
= 0;
724 cr_parms
.end_ctl
= 0;
725 cr_parms
.orvals
[0] = 0;
726 cr_parms
.andvals
[0] = ~(1<<15 | 1<<14 | 1<<13 | 1<<12 |
727 1<<11 | 1<<10 | 1<< 6 | 1<< 4);
728 smp_ctl_bit_callback(&cr_parms
);
730 /* disable all I/O interrupts */
732 cr_parms
.start_ctl
= 6;
733 cr_parms
.end_ctl
= 6;
734 cr_parms
.orvals
[6] = 0;
735 cr_parms
.andvals
[6] = ~(1<<31 | 1<<30 | 1<<29 | 1<<28 |
736 1<<27 | 1<<26 | 1<<25 | 1<<24);
737 smp_ctl_bit_callback(&cr_parms
);
739 /* disable most machine checks */
741 cr_parms
.start_ctl
= 14;
742 cr_parms
.end_ctl
= 14;
743 cr_parms
.orvals
[14] = 0;
744 cr_parms
.andvals
[14] = ~(1<<28 | 1<<27 | 1<<26 | 1<<25 | 1<<24);
745 smp_ctl_bit_callback(&cr_parms
);
747 spin_unlock_irqrestore(&smp_reserve_lock
, flags
);
752 __cpu_die(unsigned int cpu
)
754 /* Wait until target cpu is down */
755 while (!smp_cpu_not_running(cpu
))
757 printk("Processor %d spun down\n", cpu
);
764 signal_processor(smp_processor_id(), sigp_stop
);
769 #endif /* CONFIG_HOTPLUG_CPU */
772 * Cycle through the processors and setup structures.
775 void __init
smp_prepare_cpus(unsigned int max_cpus
)
781 /* request the 0x1201 emergency signal external interrupt */
782 if (register_external_interrupt(0x1201, do_ext_call_interrupt
) != 0)
783 panic("Couldn't request external interrupt 0x1201");
784 memset(lowcore_ptr
,0,sizeof(lowcore_ptr
));
786 * Initialize prefix pages and stacks for all possible cpus
788 print_cpu_info(&S390_lowcore
.cpu_data
);
790 for(i
= 0; i
< NR_CPUS
; i
++) {
791 if (!cpu_possible(i
))
793 lowcore_ptr
[i
] = (struct _lowcore
*)
794 __get_free_pages(GFP_KERNEL
|GFP_DMA
,
795 sizeof(void*) == 8 ? 1 : 0);
796 stack
= __get_free_pages(GFP_KERNEL
,ASYNC_ORDER
);
797 if (lowcore_ptr
[i
] == NULL
|| stack
== 0ULL)
798 panic("smp_boot_cpus failed to allocate memory\n");
800 *(lowcore_ptr
[i
]) = S390_lowcore
;
801 lowcore_ptr
[i
]->async_stack
= stack
+ (ASYNC_SIZE
);
802 stack
= __get_free_pages(GFP_KERNEL
,0);
804 panic("smp_boot_cpus failed to allocate memory\n");
805 lowcore_ptr
[i
]->panic_stack
= stack
+ (PAGE_SIZE
);
807 if (MACHINE_HAS_IEEE
) {
808 lowcore_ptr
[i
]->extended_save_area_addr
=
809 (__u32
) __get_free_pages(GFP_KERNEL
,0);
810 if (lowcore_ptr
[i
]->extended_save_area_addr
== 0)
811 panic("smp_boot_cpus failed to "
812 "allocate memory\n");
817 if (MACHINE_HAS_IEEE
)
818 ctl_set_bit(14, 29); /* enable extended save area */
820 set_prefix((u32
)(unsigned long) lowcore_ptr
[smp_processor_id()]);
823 if (cpu
!= smp_processor_id())
824 smp_create_idle(cpu
);
827 void __devinit
smp_prepare_boot_cpu(void)
829 BUG_ON(smp_processor_id() != 0);
831 cpu_set(0, cpu_online_map
);
832 S390_lowcore
.percpu_offset
= __per_cpu_offset
[0];
833 current_set
[0] = current
;
836 void smp_cpus_done(unsigned int max_cpus
)
841 * the frequency of the profiling timer can be changed
842 * by writing a multiplier value into /proc/profile.
844 * usually you want to run this on all CPUs ;)
846 int setup_profiling_timer(unsigned int multiplier
)
851 static DEFINE_PER_CPU(struct cpu
, cpu_devices
);
853 static int __init
topology_init(void)
859 ret
= register_cpu(&per_cpu(cpu_devices
, cpu
), cpu
, NULL
);
861 printk(KERN_WARNING
"topology_init: register_cpu %d "
862 "failed (%d)\n", cpu
, ret
);
867 subsys_initcall(topology_init
);
869 EXPORT_SYMBOL(cpu_online_map
);
870 EXPORT_SYMBOL(cpu_possible_map
);
871 EXPORT_SYMBOL(lowcore_ptr
);
872 EXPORT_SYMBOL(smp_ctl_set_bit
);
873 EXPORT_SYMBOL(smp_ctl_clear_bit
);
874 EXPORT_SYMBOL(smp_call_function
);
875 EXPORT_SYMBOL(smp_get_cpu
);
876 EXPORT_SYMBOL(smp_put_cpu
);