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>
26 #include <linux/spinlock.h>
27 #include <linux/kernel_stat.h>
28 #include <linux/smp_lock.h>
29 #include <linux/delay.h>
30 #include <linux/cache.h>
31 #include <linux/interrupt.h>
32 #include <linux/cpu.h>
33 #include <linux/timex.h>
34 #include <asm/setup.h>
36 #include <asm/pgalloc.h>
38 #include <asm/s390_ext.h>
39 #include <asm/cpcmd.h>
40 #include <asm/tlbflush.h>
41 #include <asm/timer.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
];
56 static void smp_ext_bitcall(int, ec_bit_sig
);
57 static void smp_ext_bitcall_others(ec_bit_sig
);
60 * Structure and data for smp_call_function(). This is designed to minimise
61 * static memory requirements. It also looks cleaner.
63 static DEFINE_SPINLOCK(call_lock
);
65 struct call_data_struct
{
66 void (*func
) (void *info
);
73 static struct call_data_struct
* call_data
;
76 * 'Call function' interrupt callback
78 static void do_call_function(void)
80 void (*func
) (void *info
) = call_data
->func
;
81 void *info
= call_data
->info
;
82 int wait
= call_data
->wait
;
84 atomic_inc(&call_data
->started
);
87 atomic_inc(&call_data
->finished
);
91 * this function sends a 'generic call function' IPI to all other CPUs
95 int smp_call_function (void (*func
) (void *info
), void *info
, int nonatomic
,
98 * [SUMMARY] Run a function on all other CPUs.
99 * <func> The function to run. This must be fast and non-blocking.
100 * <info> An arbitrary pointer to pass to the function.
101 * <nonatomic> currently unused.
102 * <wait> If true, wait (atomically) until function has completed on other CPUs.
103 * [RETURNS] 0 on success, else a negative status code. Does not return until
104 * remote CPUs are nearly ready to execute <<func>> or are or have executed.
106 * You must not call this function with disabled interrupts or from a
107 * hardware interrupt handler.
110 struct call_data_struct data
;
111 int cpus
= num_online_cpus()-1;
116 /* Can deadlock when interrupts are disabled or if in wrong context */
117 WARN_ON(irqs_disabled() || in_irq());
121 atomic_set(&data
.started
, 0);
124 atomic_set(&data
.finished
, 0);
126 spin_lock_bh(&call_lock
);
128 /* Send a message to all other CPUs and wait for them to respond */
129 smp_ext_bitcall_others(ec_call_function
);
131 /* Wait for response */
132 while (atomic_read(&data
.started
) != cpus
)
136 while (atomic_read(&data
.finished
) != cpus
)
138 spin_unlock_bh(&call_lock
);
144 * Call a function on one CPU
145 * cpu : the CPU the function should be executed on
147 * You must not call this function with disabled interrupts or from a
148 * hardware interrupt handler. You may call it from a bottom half.
150 * It is guaranteed that the called function runs on the specified CPU,
151 * preemption is disabled.
153 int smp_call_function_on(void (*func
) (void *info
), void *info
,
154 int nonatomic
, int wait
, int cpu
)
156 struct call_data_struct data
;
159 if (!cpu_online(cpu
))
162 /* Can deadlock when interrupts are disabled or if in wrong context */
163 WARN_ON(irqs_disabled() || in_irq());
165 /* disable preemption for local function call */
166 curr_cpu
= get_cpu();
168 if (curr_cpu
== cpu
) {
169 /* direct call to function */
177 atomic_set(&data
.started
, 0);
180 atomic_set(&data
.finished
, 0);
182 spin_lock_bh(&call_lock
);
184 smp_ext_bitcall(cpu
, ec_call_function
);
186 /* Wait for response */
187 while (atomic_read(&data
.started
) != 1)
191 while (atomic_read(&data
.finished
) != 1)
194 spin_unlock_bh(&call_lock
);
198 EXPORT_SYMBOL(smp_call_function_on
);
200 static void do_send_stop(void)
204 /* stop all processors */
205 for_each_online_cpu(cpu
) {
206 if (cpu
== smp_processor_id())
209 rc
= signal_processor(cpu
, sigp_stop
);
210 } while (rc
== sigp_busy
);
214 static void do_store_status(void)
218 /* store status of all processors in their lowcores (real 0) */
219 for_each_online_cpu(cpu
) {
220 if (cpu
== smp_processor_id())
223 rc
= signal_processor_p(
224 (__u32
)(unsigned long) lowcore_ptr
[cpu
], cpu
,
225 sigp_store_status_at_address
);
226 } while(rc
== sigp_busy
);
230 static void do_wait_for_stop(void)
234 /* Wait for all other cpus to enter stopped state */
235 for_each_online_cpu(cpu
) {
236 if (cpu
== smp_processor_id())
238 while(!smp_cpu_not_running(cpu
))
244 * this function sends a 'stop' sigp to all other CPUs in the system.
245 * it goes straight through.
247 void smp_send_stop(void)
249 /* Disable all interrupts/machine checks */
250 __load_psw_mask(psw_kernel_bits
& ~PSW_MASK_MCHECK
);
252 /* write magic number to zero page (absolute 0) */
253 lowcore_ptr
[smp_processor_id()]->panic_magic
= __PANIC_MAGIC
;
255 /* stop other processors. */
258 /* wait until other processors are stopped */
261 /* store status of other processors. */
266 * Reboot, halt and power_off routines for SMP.
269 void machine_restart_smp(char * __unused
)
275 void machine_halt_smp(void)
278 if (MACHINE_IS_VM
&& strlen(vmhalt_cmd
) > 0)
279 __cpcmd(vmhalt_cmd
, NULL
, 0, NULL
);
280 signal_processor(smp_processor_id(), sigp_stop_and_store_status
);
284 void machine_power_off_smp(void)
287 if (MACHINE_IS_VM
&& strlen(vmpoff_cmd
) > 0)
288 __cpcmd(vmpoff_cmd
, NULL
, 0, NULL
);
289 signal_processor(smp_processor_id(), sigp_stop_and_store_status
);
294 * This is the main routine where commands issued by other
298 static void do_ext_call_interrupt(__u16 code
)
303 * handle bit signal external calls
305 * For the ec_schedule signal we have to do nothing. All the work
306 * is done automatically when we return from the interrupt.
308 bits
= xchg(&S390_lowcore
.ext_call_fast
, 0);
310 if (test_bit(ec_call_function
, &bits
))
315 * Send an external call sigp to another cpu and return without waiting
316 * for its completion.
318 static void smp_ext_bitcall(int cpu
, ec_bit_sig sig
)
321 * Set signaling bit in lowcore of target cpu and kick it
323 set_bit(sig
, (unsigned long *) &lowcore_ptr
[cpu
]->ext_call_fast
);
324 while(signal_processor(cpu
, sigp_emergency_signal
) == sigp_busy
)
329 * Send an external call sigp to every other cpu in the system and
330 * return without waiting for its completion.
332 static void smp_ext_bitcall_others(ec_bit_sig sig
)
336 for_each_online_cpu(cpu
) {
337 if (cpu
== smp_processor_id())
340 * Set signaling bit in lowcore of target cpu and kick it
342 set_bit(sig
, (unsigned long *) &lowcore_ptr
[cpu
]->ext_call_fast
);
343 while (signal_processor(cpu
, sigp_emergency_signal
) == sigp_busy
)
350 * this function sends a 'purge tlb' signal to another CPU.
352 void smp_ptlb_callback(void *info
)
357 void smp_ptlb_all(void)
359 on_each_cpu(smp_ptlb_callback
, NULL
, 0, 1);
361 EXPORT_SYMBOL(smp_ptlb_all
);
362 #endif /* ! CONFIG_64BIT */
365 * this function sends a 'reschedule' IPI to another CPU.
366 * it goes straight through and wastes no time serializing
367 * anything. Worst case is that we lose a reschedule ...
369 void smp_send_reschedule(int cpu
)
371 smp_ext_bitcall(cpu
, ec_schedule
);
375 * parameter area for the set/clear control bit callbacks
377 struct ec_creg_mask_parms
{
378 unsigned long orvals
[16];
379 unsigned long andvals
[16];
383 * callback for setting/clearing control bits
385 static void smp_ctl_bit_callback(void *info
) {
386 struct ec_creg_mask_parms
*pp
= info
;
387 unsigned long cregs
[16];
390 __ctl_store(cregs
, 0, 15);
391 for (i
= 0; i
<= 15; i
++)
392 cregs
[i
] = (cregs
[i
] & pp
->andvals
[i
]) | pp
->orvals
[i
];
393 __ctl_load(cregs
, 0, 15);
397 * Set a bit in a control register of all cpus
399 void smp_ctl_set_bit(int cr
, int bit
)
401 struct ec_creg_mask_parms parms
;
403 memset(&parms
.orvals
, 0, sizeof(parms
.orvals
));
404 memset(&parms
.andvals
, 0xff, sizeof(parms
.andvals
));
405 parms
.orvals
[cr
] = 1 << bit
;
406 on_each_cpu(smp_ctl_bit_callback
, &parms
, 0, 1);
410 * Clear a bit in a control register of all cpus
412 void smp_ctl_clear_bit(int cr
, int bit
)
414 struct ec_creg_mask_parms parms
;
416 memset(&parms
.orvals
, 0, sizeof(parms
.orvals
));
417 memset(&parms
.andvals
, 0xff, sizeof(parms
.andvals
));
418 parms
.andvals
[cr
] = ~(1L << bit
);
419 on_each_cpu(smp_ctl_bit_callback
, &parms
, 0, 1);
423 * Lets check how many CPUs we have.
427 __init
smp_count_cpus(void)
429 unsigned int cpu
, num_cpus
;
433 * cpu 0 is the boot cpu. See smp_prepare_boot_cpu.
436 boot_cpu_addr
= S390_lowcore
.cpu_data
.cpu_addr
;
437 current_thread_info()->cpu
= 0;
439 for (cpu
= 0; cpu
<= 65535; cpu
++) {
440 if ((__u16
) cpu
== boot_cpu_addr
)
442 __cpu_logical_map
[1] = (__u16
) cpu
;
443 if (signal_processor(1, sigp_sense
) ==
444 sigp_not_operational
)
449 printk("Detected %d CPU's\n",(int) num_cpus
);
450 printk("Boot cpu address %2X\n", boot_cpu_addr
);
456 * Activate a secondary processor.
458 int __devinit
start_secondary(void *cpuvoid
)
463 /* Enable TOD clock interrupts on the secondary cpu. */
465 #ifdef CONFIG_VIRT_TIMER
466 /* Enable cpu timer interrupts on the secondary cpu. */
469 /* Enable pfault pseudo page faults on this cpu. */
472 /* Mark this cpu as online */
473 cpu_set(smp_processor_id(), cpu_online_map
);
474 /* Switch on interrupts */
476 /* Print info about this processor */
477 print_cpu_info(&S390_lowcore
.cpu_data
);
478 /* cpu_idle will call schedule for us */
483 static void __init
smp_create_idle(unsigned int cpu
)
485 struct task_struct
*p
;
488 * don't care about the psw and regs settings since we'll never
489 * reschedule the forked task.
493 panic("failed fork for CPU %u: %li", cpu
, PTR_ERR(p
));
494 current_set
[cpu
] = p
;
497 /* Reserving and releasing of CPUs */
499 static DEFINE_SPINLOCK(smp_reserve_lock
);
500 static int smp_cpu_reserved
[NR_CPUS
];
503 smp_get_cpu(cpumask_t cpu_mask
)
508 spin_lock_irqsave(&smp_reserve_lock
, flags
);
509 /* Try to find an already reserved cpu. */
510 for_each_cpu_mask(cpu
, cpu_mask
) {
511 if (smp_cpu_reserved
[cpu
] != 0) {
512 smp_cpu_reserved
[cpu
]++;
517 /* Reserve a new cpu from cpu_mask. */
518 for_each_cpu_mask(cpu
, cpu_mask
) {
519 if (cpu_online(cpu
)) {
520 smp_cpu_reserved
[cpu
]++;
526 spin_unlock_irqrestore(&smp_reserve_lock
, flags
);
535 spin_lock_irqsave(&smp_reserve_lock
, flags
);
536 smp_cpu_reserved
[cpu
]--;
537 spin_unlock_irqrestore(&smp_reserve_lock
, flags
);
545 /* Check for stopped state */
546 if (signal_processor_ps(&status
, 0, cpu
, sigp_sense
) == sigp_status_stored
) {
553 /* Upping and downing of CPUs */
556 __cpu_up(unsigned int cpu
)
558 struct task_struct
*idle
;
559 struct _lowcore
*cpu_lowcore
;
560 struct stack_frame
*sf
;
564 for (curr_cpu
= 0; curr_cpu
<= 65535; curr_cpu
++) {
565 __cpu_logical_map
[cpu
] = (__u16
) curr_cpu
;
566 if (cpu_stopped(cpu
))
570 if (!cpu_stopped(cpu
))
573 ccode
= signal_processor_p((__u32
)(unsigned long)(lowcore_ptr
[cpu
]),
574 cpu
, sigp_set_prefix
);
576 printk("sigp_set_prefix failed for cpu %d "
577 "with condition code %d\n",
578 (int) cpu
, (int) ccode
);
582 idle
= current_set
[cpu
];
583 cpu_lowcore
= lowcore_ptr
[cpu
];
584 cpu_lowcore
->kernel_stack
= (unsigned long)
585 task_stack_page(idle
) + (THREAD_SIZE
);
586 sf
= (struct stack_frame
*) (cpu_lowcore
->kernel_stack
587 - sizeof(struct pt_regs
)
588 - sizeof(struct stack_frame
));
589 memset(sf
, 0, sizeof(struct stack_frame
));
590 sf
->gprs
[9] = (unsigned long) sf
;
591 cpu_lowcore
->save_area
[15] = (unsigned long) sf
;
592 __ctl_store(cpu_lowcore
->cregs_save_area
[0], 0, 15);
595 : : "a" (&cpu_lowcore
->access_regs_save_area
) : "memory");
596 cpu_lowcore
->percpu_offset
= __per_cpu_offset
[cpu
];
597 cpu_lowcore
->current_task
= (unsigned long) idle
;
598 cpu_lowcore
->cpu_data
.cpu_nr
= cpu
;
601 while (signal_processor(cpu
,sigp_restart
) == sigp_busy
)
604 while (!cpu_online(cpu
))
609 static unsigned int __initdata additional_cpus
;
610 static unsigned int __initdata possible_cpus
;
612 void __init
smp_setup_cpu_possible_map(void)
614 unsigned int phy_cpus
, pos_cpus
, cpu
;
616 phy_cpus
= smp_count_cpus();
617 pos_cpus
= min(phy_cpus
+ additional_cpus
, (unsigned int) NR_CPUS
);
620 pos_cpus
= min(possible_cpus
, (unsigned int) NR_CPUS
);
622 for (cpu
= 0; cpu
< pos_cpus
; cpu
++)
623 cpu_set(cpu
, cpu_possible_map
);
625 phy_cpus
= min(phy_cpus
, pos_cpus
);
627 for (cpu
= 0; cpu
< phy_cpus
; cpu
++)
628 cpu_set(cpu
, cpu_present_map
);
631 #ifdef CONFIG_HOTPLUG_CPU
633 static int __init
setup_additional_cpus(char *s
)
635 additional_cpus
= simple_strtoul(s
, NULL
, 0);
638 early_param("additional_cpus", setup_additional_cpus
);
640 static int __init
setup_possible_cpus(char *s
)
642 possible_cpus
= simple_strtoul(s
, NULL
, 0);
645 early_param("possible_cpus", setup_possible_cpus
);
651 struct ec_creg_mask_parms cr_parms
;
652 int cpu
= smp_processor_id();
654 spin_lock_irqsave(&smp_reserve_lock
, flags
);
655 if (smp_cpu_reserved
[cpu
] != 0) {
656 spin_unlock_irqrestore(&smp_reserve_lock
, flags
);
659 cpu_clear(cpu
, cpu_online_map
);
661 /* Disable pfault pseudo page faults on this cpu. */
664 memset(&cr_parms
.orvals
, 0, sizeof(cr_parms
.orvals
));
665 memset(&cr_parms
.andvals
, 0xff, sizeof(cr_parms
.andvals
));
667 /* disable all external interrupts */
668 cr_parms
.orvals
[0] = 0;
669 cr_parms
.andvals
[0] = ~(1<<15 | 1<<14 | 1<<13 | 1<<12 |
670 1<<11 | 1<<10 | 1<< 6 | 1<< 4);
671 /* disable all I/O interrupts */
672 cr_parms
.orvals
[6] = 0;
673 cr_parms
.andvals
[6] = ~(1<<31 | 1<<30 | 1<<29 | 1<<28 |
674 1<<27 | 1<<26 | 1<<25 | 1<<24);
675 /* disable most machine checks */
676 cr_parms
.orvals
[14] = 0;
677 cr_parms
.andvals
[14] = ~(1<<28 | 1<<27 | 1<<26 | 1<<25 | 1<<24);
679 smp_ctl_bit_callback(&cr_parms
);
681 spin_unlock_irqrestore(&smp_reserve_lock
, flags
);
686 __cpu_die(unsigned int cpu
)
688 /* Wait until target cpu is down */
689 while (!smp_cpu_not_running(cpu
))
691 printk("Processor %d spun down\n", cpu
);
698 signal_processor(smp_processor_id(), sigp_stop
);
703 #endif /* CONFIG_HOTPLUG_CPU */
706 * Cycle through the processors and setup structures.
709 void __init
smp_prepare_cpus(unsigned int max_cpus
)
715 /* request the 0x1201 emergency signal external interrupt */
716 if (register_external_interrupt(0x1201, do_ext_call_interrupt
) != 0)
717 panic("Couldn't request external interrupt 0x1201");
718 memset(lowcore_ptr
,0,sizeof(lowcore_ptr
));
720 * Initialize prefix pages and stacks for all possible cpus
722 print_cpu_info(&S390_lowcore
.cpu_data
);
724 for_each_possible_cpu(i
) {
725 lowcore_ptr
[i
] = (struct _lowcore
*)
726 __get_free_pages(GFP_KERNEL
|GFP_DMA
,
727 sizeof(void*) == 8 ? 1 : 0);
728 stack
= __get_free_pages(GFP_KERNEL
,ASYNC_ORDER
);
729 if (lowcore_ptr
[i
] == NULL
|| stack
== 0ULL)
730 panic("smp_boot_cpus failed to allocate memory\n");
732 *(lowcore_ptr
[i
]) = S390_lowcore
;
733 lowcore_ptr
[i
]->async_stack
= stack
+ (ASYNC_SIZE
);
734 stack
= __get_free_pages(GFP_KERNEL
,0);
736 panic("smp_boot_cpus failed to allocate memory\n");
737 lowcore_ptr
[i
]->panic_stack
= stack
+ (PAGE_SIZE
);
739 if (MACHINE_HAS_IEEE
) {
740 lowcore_ptr
[i
]->extended_save_area_addr
=
741 (__u32
) __get_free_pages(GFP_KERNEL
,0);
742 if (lowcore_ptr
[i
]->extended_save_area_addr
== 0)
743 panic("smp_boot_cpus failed to "
744 "allocate memory\n");
749 if (MACHINE_HAS_IEEE
)
750 ctl_set_bit(14, 29); /* enable extended save area */
752 set_prefix((u32
)(unsigned long) lowcore_ptr
[smp_processor_id()]);
754 for_each_possible_cpu(cpu
)
755 if (cpu
!= smp_processor_id())
756 smp_create_idle(cpu
);
759 void __devinit
smp_prepare_boot_cpu(void)
761 BUG_ON(smp_processor_id() != 0);
763 cpu_set(0, cpu_online_map
);
764 S390_lowcore
.percpu_offset
= __per_cpu_offset
[0];
765 current_set
[0] = current
;
768 void smp_cpus_done(unsigned int max_cpus
)
770 cpu_present_map
= cpu_possible_map
;
774 * the frequency of the profiling timer can be changed
775 * by writing a multiplier value into /proc/profile.
777 * usually you want to run this on all CPUs ;)
779 int setup_profiling_timer(unsigned int multiplier
)
784 static DEFINE_PER_CPU(struct cpu
, cpu_devices
);
786 static int __init
topology_init(void)
791 for_each_possible_cpu(cpu
) {
792 struct cpu
*c
= &per_cpu(cpu_devices
, cpu
);
795 ret
= register_cpu(c
, cpu
);
797 printk(KERN_WARNING
"topology_init: register_cpu %d "
798 "failed (%d)\n", cpu
, ret
);
803 subsys_initcall(topology_init
);
805 EXPORT_SYMBOL(cpu_online_map
);
806 EXPORT_SYMBOL(cpu_possible_map
);
807 EXPORT_SYMBOL(lowcore_ptr
);
808 EXPORT_SYMBOL(smp_ctl_set_bit
);
809 EXPORT_SYMBOL(smp_ctl_clear_bit
);
810 EXPORT_SYMBOL(smp_call_function
);
811 EXPORT_SYMBOL(smp_get_cpu
);
812 EXPORT_SYMBOL(smp_put_cpu
);