2 * arch/s390/kernel/smp.c
4 * Copyright IBM Corp. 1999,2007
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/delay.h>
29 #include <linux/cache.h>
30 #include <linux/interrupt.h>
31 #include <linux/cpu.h>
32 #include <linux/timex.h>
33 #include <linux/bootmem.h>
35 #include <asm/setup.h>
37 #include <asm/pgalloc.h>
39 #include <asm/s390_ext.h>
40 #include <asm/cpcmd.h>
41 #include <asm/tlbflush.h>
42 #include <asm/timer.h>
43 #include <asm/lowcore.h>
46 * An array with a pointer the lowcore of every CPU.
48 struct _lowcore
*lowcore_ptr
[NR_CPUS
];
49 EXPORT_SYMBOL(lowcore_ptr
);
51 cpumask_t cpu_online_map
= CPU_MASK_NONE
;
52 EXPORT_SYMBOL(cpu_online_map
);
54 cpumask_t cpu_possible_map
= CPU_MASK_NONE
;
55 EXPORT_SYMBOL(cpu_possible_map
);
57 static struct task_struct
*current_set
[NR_CPUS
];
59 static void smp_ext_bitcall(int, ec_bit_sig
);
62 * Structure and data for __smp_call_function_map(). This is designed to
63 * minimise static memory requirements. It also looks cleaner.
65 static DEFINE_SPINLOCK(call_lock
);
67 struct call_data_struct
{
68 void (*func
) (void *info
);
75 static struct call_data_struct
*call_data
;
78 * 'Call function' interrupt callback
80 static void do_call_function(void)
82 void (*func
) (void *info
) = call_data
->func
;
83 void *info
= call_data
->info
;
84 int wait
= call_data
->wait
;
86 cpu_set(smp_processor_id(), call_data
->started
);
89 cpu_set(smp_processor_id(), call_data
->finished
);;
92 static void __smp_call_function_map(void (*func
) (void *info
), void *info
,
93 int nonatomic
, int wait
, cpumask_t map
)
95 struct call_data_struct data
;
99 * Can deadlock when interrupts are disabled or if in wrong context.
101 WARN_ON(irqs_disabled() || in_irq());
104 * Check for local function call. We have to have the same call order
105 * as in on_each_cpu() because of machine_restart_smp().
107 if (cpu_isset(smp_processor_id(), map
)) {
109 cpu_clear(smp_processor_id(), map
);
112 cpus_and(map
, map
, cpu_online_map
);
118 data
.started
= CPU_MASK_NONE
;
121 data
.finished
= CPU_MASK_NONE
;
123 spin_lock_bh(&call_lock
);
126 for_each_cpu_mask(cpu
, map
)
127 smp_ext_bitcall(cpu
, ec_call_function
);
129 /* Wait for response */
130 while (!cpus_equal(map
, data
.started
))
134 while (!cpus_equal(map
, data
.finished
))
137 spin_unlock_bh(&call_lock
);
148 * @func: the function to run; this must be fast and non-blocking
149 * @info: an arbitrary pointer to pass to the function
151 * @wait: if true, wait (atomically) until function has completed on other CPUs
153 * Run a function on all other CPUs.
155 * You must not call this function with disabled interrupts, from a
156 * hardware interrupt handler or from a bottom half.
158 int smp_call_function(void (*func
) (void *info
), void *info
, int nonatomic
,
164 map
= cpu_online_map
;
165 cpu_clear(smp_processor_id(), map
);
166 __smp_call_function_map(func
, info
, nonatomic
, wait
, map
);
170 EXPORT_SYMBOL(smp_call_function
);
173 * smp_call_function_on:
174 * @func: the function to run; this must be fast and non-blocking
175 * @info: an arbitrary pointer to pass to the function
177 * @wait: if true, wait (atomically) until function has completed on other CPUs
178 * @cpu: the CPU where func should run
180 * Run a function on one processor.
182 * You must not call this function with disabled interrupts, from a
183 * hardware interrupt handler or from a bottom half.
185 int smp_call_function_on(void (*func
) (void *info
), void *info
, int nonatomic
,
188 cpumask_t map
= CPU_MASK_NONE
;
192 __smp_call_function_map(func
, info
, nonatomic
, wait
, map
);
196 EXPORT_SYMBOL(smp_call_function_on
);
198 static void do_send_stop(void)
202 /* stop all processors */
203 for_each_online_cpu(cpu
) {
204 if (cpu
== smp_processor_id())
207 rc
= signal_processor(cpu
, sigp_stop
);
208 } while (rc
== sigp_busy
);
212 static void do_store_status(void)
216 /* store status of all processors in their lowcores (real 0) */
217 for_each_online_cpu(cpu
) {
218 if (cpu
== smp_processor_id())
221 rc
= signal_processor_p(
222 (__u32
)(unsigned long) lowcore_ptr
[cpu
], cpu
,
223 sigp_store_status_at_address
);
224 } while (rc
== sigp_busy
);
228 static void do_wait_for_stop(void)
232 /* Wait for all other cpus to enter stopped state */
233 for_each_online_cpu(cpu
) {
234 if (cpu
== smp_processor_id())
236 while (!smp_cpu_not_running(cpu
))
242 * this function sends a 'stop' sigp to all other CPUs in the system.
243 * it goes straight through.
245 void smp_send_stop(void)
247 /* Disable all interrupts/machine checks */
248 __load_psw_mask(psw_kernel_bits
& ~PSW_MASK_MCHECK
);
250 /* write magic number to zero page (absolute 0) */
251 lowcore_ptr
[smp_processor_id()]->panic_magic
= __PANIC_MAGIC
;
253 /* stop other processors. */
256 /* wait until other processors are stopped */
259 /* store status of other processors. */
264 * Reboot, halt and power_off routines for SMP.
266 void machine_restart_smp(char *__unused
)
272 void machine_halt_smp(void)
275 if (MACHINE_IS_VM
&& strlen(vmhalt_cmd
) > 0)
276 __cpcmd(vmhalt_cmd
, NULL
, 0, NULL
);
277 signal_processor(smp_processor_id(), sigp_stop_and_store_status
);
281 void machine_power_off_smp(void)
284 if (MACHINE_IS_VM
&& strlen(vmpoff_cmd
) > 0)
285 __cpcmd(vmpoff_cmd
, NULL
, 0, NULL
);
286 signal_processor(smp_processor_id(), sigp_stop_and_store_status
);
291 * This is the main routine where commands issued by other
295 static void do_ext_call_interrupt(__u16 code
)
300 * handle bit signal external calls
302 * For the ec_schedule signal we have to do nothing. All the work
303 * is done automatically when we return from the interrupt.
305 bits
= xchg(&S390_lowcore
.ext_call_fast
, 0);
307 if (test_bit(ec_call_function
, &bits
))
312 * Send an external call sigp to another cpu and return without waiting
313 * for its completion.
315 static void smp_ext_bitcall(int cpu
, ec_bit_sig sig
)
318 * Set signaling bit in lowcore of target cpu and kick it
320 set_bit(sig
, (unsigned long *) &lowcore_ptr
[cpu
]->ext_call_fast
);
321 while (signal_processor(cpu
, sigp_emergency_signal
) == sigp_busy
)
327 * this function sends a 'purge tlb' signal to another CPU.
329 void smp_ptlb_callback(void *info
)
334 void smp_ptlb_all(void)
336 on_each_cpu(smp_ptlb_callback
, NULL
, 0, 1);
338 EXPORT_SYMBOL(smp_ptlb_all
);
339 #endif /* ! CONFIG_64BIT */
342 * this function sends a 'reschedule' IPI to another CPU.
343 * it goes straight through and wastes no time serializing
344 * anything. Worst case is that we lose a reschedule ...
346 void smp_send_reschedule(int cpu
)
348 smp_ext_bitcall(cpu
, ec_schedule
);
352 * parameter area for the set/clear control bit callbacks
354 struct ec_creg_mask_parms
{
355 unsigned long orvals
[16];
356 unsigned long andvals
[16];
360 * callback for setting/clearing control bits
362 static void smp_ctl_bit_callback(void *info
)
364 struct ec_creg_mask_parms
*pp
= info
;
365 unsigned long cregs
[16];
368 __ctl_store(cregs
, 0, 15);
369 for (i
= 0; i
<= 15; i
++)
370 cregs
[i
] = (cregs
[i
] & pp
->andvals
[i
]) | pp
->orvals
[i
];
371 __ctl_load(cregs
, 0, 15);
375 * Set a bit in a control register of all cpus
377 void smp_ctl_set_bit(int cr
, int bit
)
379 struct ec_creg_mask_parms parms
;
381 memset(&parms
.orvals
, 0, sizeof(parms
.orvals
));
382 memset(&parms
.andvals
, 0xff, sizeof(parms
.andvals
));
383 parms
.orvals
[cr
] = 1 << bit
;
384 on_each_cpu(smp_ctl_bit_callback
, &parms
, 0, 1);
386 EXPORT_SYMBOL(smp_ctl_set_bit
);
389 * Clear a bit in a control register of all cpus
391 void smp_ctl_clear_bit(int cr
, int bit
)
393 struct ec_creg_mask_parms parms
;
395 memset(&parms
.orvals
, 0, sizeof(parms
.orvals
));
396 memset(&parms
.andvals
, 0xff, sizeof(parms
.andvals
));
397 parms
.andvals
[cr
] = ~(1L << bit
);
398 on_each_cpu(smp_ctl_bit_callback
, &parms
, 0, 1);
400 EXPORT_SYMBOL(smp_ctl_clear_bit
);
402 #if defined(CONFIG_ZFCPDUMP) || defined(CONFIG_ZFCPDUMP_MODULE)
405 * zfcpdump_prefix_array holds prefix registers for the following scenario:
406 * 64 bit zfcpdump kernel and 31 bit kernel which is to be dumped. We have to
407 * save its prefix registers, since they get lost, when switching from 31 bit
410 unsigned int zfcpdump_prefix_array
[NR_CPUS
+ 1] \
411 __attribute__((__section__(".data")));
413 static void __init
smp_get_save_areas(void)
415 unsigned int cpu
, cpu_num
, rc
;
418 if (ipl_info
.type
!= IPL_TYPE_FCP_DUMP
)
420 boot_cpu_addr
= S390_lowcore
.cpu_data
.cpu_addr
;
422 for (cpu
= 0; cpu
<= 65535; cpu
++) {
423 if ((u16
) cpu
== boot_cpu_addr
)
425 __cpu_logical_map
[1] = (__u16
) cpu
;
426 if (signal_processor(1, sigp_sense
) == sigp_not_operational
)
428 if (cpu_num
>= NR_CPUS
) {
429 printk("WARNING: Registers for cpu %i are not "
430 "saved, since dump kernel was compiled with"
431 "NR_CPUS=%i!\n", cpu_num
, NR_CPUS
);
434 zfcpdump_save_areas
[cpu_num
] =
435 alloc_bootmem(sizeof(union save_area
));
437 rc
= signal_processor(1, sigp_stop_and_store_status
);
442 memcpy(zfcpdump_save_areas
[cpu_num
],
443 (void *)(unsigned long) store_prefix() +
444 SAVE_AREA_BASE
, SAVE_AREA_SIZE
);
446 /* copy original prefix register */
447 zfcpdump_save_areas
[cpu_num
]->s390x
.pref_reg
=
448 zfcpdump_prefix_array
[cpu_num
];
454 union save_area
*zfcpdump_save_areas
[NR_CPUS
+ 1];
455 EXPORT_SYMBOL_GPL(zfcpdump_save_areas
);
458 #define smp_get_save_areas() do { } while (0)
462 * Lets check how many CPUs we have.
465 static unsigned int __init
smp_count_cpus(void)
467 unsigned int cpu
, num_cpus
;
471 * cpu 0 is the boot cpu. See smp_prepare_boot_cpu.
474 boot_cpu_addr
= S390_lowcore
.cpu_data
.cpu_addr
;
475 current_thread_info()->cpu
= 0;
477 for (cpu
= 0; cpu
<= 65535; cpu
++) {
478 if ((__u16
) cpu
== boot_cpu_addr
)
480 __cpu_logical_map
[1] = (__u16
) cpu
;
481 if (signal_processor(1, sigp_sense
) == sigp_not_operational
)
486 printk("Detected %d CPU's\n", (int) num_cpus
);
487 printk("Boot cpu address %2X\n", boot_cpu_addr
);
493 * Activate a secondary processor.
495 int __devinit
start_secondary(void *cpuvoid
)
500 /* Enable TOD clock interrupts on the secondary cpu. */
502 #ifdef CONFIG_VIRT_TIMER
503 /* Enable cpu timer interrupts on the secondary cpu. */
506 /* Enable pfault pseudo page faults on this cpu. */
509 /* Mark this cpu as online */
510 cpu_set(smp_processor_id(), cpu_online_map
);
511 /* Switch on interrupts */
513 /* Print info about this processor */
514 print_cpu_info(&S390_lowcore
.cpu_data
);
515 /* cpu_idle will call schedule for us */
520 static void __init
smp_create_idle(unsigned int cpu
)
522 struct task_struct
*p
;
525 * don't care about the psw and regs settings since we'll never
526 * reschedule the forked task.
530 panic("failed fork for CPU %u: %li", cpu
, PTR_ERR(p
));
531 current_set
[cpu
] = p
;
534 static int cpu_stopped(int cpu
)
538 /* Check for stopped state */
539 if (signal_processor_ps(&status
, 0, cpu
, sigp_sense
) ==
540 sigp_status_stored
) {
547 /* Upping and downing of CPUs */
549 int __cpu_up(unsigned int cpu
)
551 struct task_struct
*idle
;
552 struct _lowcore
*cpu_lowcore
;
553 struct stack_frame
*sf
;
557 for (curr_cpu
= 0; curr_cpu
<= 65535; curr_cpu
++) {
558 __cpu_logical_map
[cpu
] = (__u16
) curr_cpu
;
559 if (cpu_stopped(cpu
))
563 if (!cpu_stopped(cpu
))
566 ccode
= signal_processor_p((__u32
)(unsigned long)(lowcore_ptr
[cpu
]),
567 cpu
, sigp_set_prefix
);
569 printk("sigp_set_prefix failed for cpu %d "
570 "with condition code %d\n",
571 (int) cpu
, (int) ccode
);
575 idle
= current_set
[cpu
];
576 cpu_lowcore
= lowcore_ptr
[cpu
];
577 cpu_lowcore
->kernel_stack
= (unsigned long)
578 task_stack_page(idle
) + THREAD_SIZE
;
579 sf
= (struct stack_frame
*) (cpu_lowcore
->kernel_stack
580 - sizeof(struct pt_regs
)
581 - sizeof(struct stack_frame
));
582 memset(sf
, 0, sizeof(struct stack_frame
));
583 sf
->gprs
[9] = (unsigned long) sf
;
584 cpu_lowcore
->save_area
[15] = (unsigned long) sf
;
585 __ctl_store(cpu_lowcore
->cregs_save_area
[0], 0, 15);
588 : : "a" (&cpu_lowcore
->access_regs_save_area
) : "memory");
589 cpu_lowcore
->percpu_offset
= __per_cpu_offset
[cpu
];
590 cpu_lowcore
->current_task
= (unsigned long) idle
;
591 cpu_lowcore
->cpu_data
.cpu_nr
= cpu
;
594 while (signal_processor(cpu
, sigp_restart
) == sigp_busy
)
597 while (!cpu_online(cpu
))
602 static unsigned int __initdata additional_cpus
;
603 static unsigned int __initdata possible_cpus
;
605 void __init
smp_setup_cpu_possible_map(void)
607 unsigned int phy_cpus
, pos_cpus
, cpu
;
609 smp_get_save_areas();
610 phy_cpus
= smp_count_cpus();
611 pos_cpus
= min(phy_cpus
+ additional_cpus
, (unsigned int) NR_CPUS
);
614 pos_cpus
= min(possible_cpus
, (unsigned int) NR_CPUS
);
616 for (cpu
= 0; cpu
< pos_cpus
; cpu
++)
617 cpu_set(cpu
, cpu_possible_map
);
619 phy_cpus
= min(phy_cpus
, pos_cpus
);
621 for (cpu
= 0; cpu
< phy_cpus
; cpu
++)
622 cpu_set(cpu
, cpu_present_map
);
625 #ifdef CONFIG_HOTPLUG_CPU
627 static int __init
setup_additional_cpus(char *s
)
629 additional_cpus
= simple_strtoul(s
, NULL
, 0);
632 early_param("additional_cpus", setup_additional_cpus
);
634 static int __init
setup_possible_cpus(char *s
)
636 possible_cpus
= simple_strtoul(s
, NULL
, 0);
639 early_param("possible_cpus", setup_possible_cpus
);
641 int __cpu_disable(void)
643 struct ec_creg_mask_parms cr_parms
;
644 int cpu
= smp_processor_id();
646 cpu_clear(cpu
, cpu_online_map
);
648 /* Disable pfault pseudo page faults on this cpu. */
651 memset(&cr_parms
.orvals
, 0, sizeof(cr_parms
.orvals
));
652 memset(&cr_parms
.andvals
, 0xff, sizeof(cr_parms
.andvals
));
654 /* disable all external interrupts */
655 cr_parms
.orvals
[0] = 0;
656 cr_parms
.andvals
[0] = ~(1 << 15 | 1 << 14 | 1 << 13 | 1 << 12 |
657 1 << 11 | 1 << 10 | 1 << 6 | 1 << 4);
658 /* disable all I/O interrupts */
659 cr_parms
.orvals
[6] = 0;
660 cr_parms
.andvals
[6] = ~(1 << 31 | 1 << 30 | 1 << 29 | 1 << 28 |
661 1 << 27 | 1 << 26 | 1 << 25 | 1 << 24);
662 /* disable most machine checks */
663 cr_parms
.orvals
[14] = 0;
664 cr_parms
.andvals
[14] = ~(1 << 28 | 1 << 27 | 1 << 26 |
667 smp_ctl_bit_callback(&cr_parms
);
672 void __cpu_die(unsigned int cpu
)
674 /* Wait until target cpu is down */
675 while (!smp_cpu_not_running(cpu
))
677 printk("Processor %d spun down\n", cpu
);
683 signal_processor(smp_processor_id(), sigp_stop
);
688 #endif /* CONFIG_HOTPLUG_CPU */
691 * Cycle through the processors and setup structures.
694 void __init
smp_prepare_cpus(unsigned int max_cpus
)
700 /* request the 0x1201 emergency signal external interrupt */
701 if (register_external_interrupt(0x1201, do_ext_call_interrupt
) != 0)
702 panic("Couldn't request external interrupt 0x1201");
703 memset(lowcore_ptr
, 0, sizeof(lowcore_ptr
));
705 * Initialize prefix pages and stacks for all possible cpus
707 print_cpu_info(&S390_lowcore
.cpu_data
);
709 for_each_possible_cpu(i
) {
710 lowcore_ptr
[i
] = (struct _lowcore
*)
711 __get_free_pages(GFP_KERNEL
| GFP_DMA
,
712 sizeof(void*) == 8 ? 1 : 0);
713 stack
= __get_free_pages(GFP_KERNEL
, ASYNC_ORDER
);
714 if (!lowcore_ptr
[i
] || !stack
)
715 panic("smp_boot_cpus failed to allocate memory\n");
717 *(lowcore_ptr
[i
]) = S390_lowcore
;
718 lowcore_ptr
[i
]->async_stack
= stack
+ ASYNC_SIZE
;
719 stack
= __get_free_pages(GFP_KERNEL
, 0);
721 panic("smp_boot_cpus failed to allocate memory\n");
722 lowcore_ptr
[i
]->panic_stack
= stack
+ PAGE_SIZE
;
724 if (MACHINE_HAS_IEEE
) {
725 lowcore_ptr
[i
]->extended_save_area_addr
=
726 (__u32
) __get_free_pages(GFP_KERNEL
, 0);
727 if (!lowcore_ptr
[i
]->extended_save_area_addr
)
728 panic("smp_boot_cpus failed to "
729 "allocate memory\n");
734 if (MACHINE_HAS_IEEE
)
735 ctl_set_bit(14, 29); /* enable extended save area */
737 set_prefix((u32
)(unsigned long) lowcore_ptr
[smp_processor_id()]);
739 for_each_possible_cpu(cpu
)
740 if (cpu
!= smp_processor_id())
741 smp_create_idle(cpu
);
744 void __devinit
smp_prepare_boot_cpu(void)
746 BUG_ON(smp_processor_id() != 0);
748 cpu_set(0, cpu_online_map
);
749 S390_lowcore
.percpu_offset
= __per_cpu_offset
[0];
750 current_set
[0] = current
;
753 void smp_cpus_done(unsigned int max_cpus
)
755 cpu_present_map
= cpu_possible_map
;
759 * the frequency of the profiling timer can be changed
760 * by writing a multiplier value into /proc/profile.
762 * usually you want to run this on all CPUs ;)
764 int setup_profiling_timer(unsigned int multiplier
)
769 static DEFINE_PER_CPU(struct cpu
, cpu_devices
);
771 static ssize_t
show_capability(struct sys_device
*dev
, char *buf
)
773 unsigned int capability
;
776 rc
= get_cpu_capability(&capability
);
779 return sprintf(buf
, "%u\n", capability
);
781 static SYSDEV_ATTR(capability
, 0444, show_capability
, NULL
);
783 static int __cpuinit
smp_cpu_notify(struct notifier_block
*self
,
784 unsigned long action
, void *hcpu
)
786 unsigned int cpu
= (unsigned int)(long)hcpu
;
787 struct cpu
*c
= &per_cpu(cpu_devices
, cpu
);
788 struct sys_device
*s
= &c
->sysdev
;
792 case CPU_ONLINE_FROZEN
:
793 if (sysdev_create_file(s
, &attr_capability
))
797 case CPU_DEAD_FROZEN
:
798 sysdev_remove_file(s
, &attr_capability
);
804 static struct notifier_block __cpuinitdata smp_cpu_nb
= {
805 .notifier_call
= smp_cpu_notify
,
808 static int __init
topology_init(void)
812 register_cpu_notifier(&smp_cpu_nb
);
814 for_each_possible_cpu(cpu
) {
815 struct cpu
*c
= &per_cpu(cpu_devices
, cpu
);
816 struct sys_device
*s
= &c
->sysdev
;
819 register_cpu(c
, cpu
);
820 if (!cpu_online(cpu
))
823 sysdev_create_file(s
, &attr_capability
);
827 subsys_initcall(topology_init
);