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 5B * 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 or from a bottom half handler.
110 struct call_data_struct data
;
111 int cpus
= num_online_cpus()-1;
116 /* Can deadlock when called with interrupts disabled */
117 WARN_ON(irqs_disabled());
121 atomic_set(&data
.started
, 0);
124 atomic_set(&data
.finished
, 0);
126 spin_lock(&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(&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 /* disable preemption for local function call */
163 curr_cpu
= get_cpu();
165 if (curr_cpu
== cpu
) {
166 /* direct call to function */
174 atomic_set(&data
.started
, 0);
177 atomic_set(&data
.finished
, 0);
179 spin_lock_bh(&call_lock
);
181 smp_ext_bitcall(cpu
, ec_call_function
);
183 /* Wait for response */
184 while (atomic_read(&data
.started
) != 1)
188 while (atomic_read(&data
.finished
) != 1)
191 spin_unlock_bh(&call_lock
);
195 EXPORT_SYMBOL(smp_call_function_on
);
197 static void do_send_stop(void)
201 /* stop all processors */
202 for_each_online_cpu(cpu
) {
203 if (cpu
== smp_processor_id())
206 rc
= signal_processor(cpu
, sigp_stop
);
207 } while (rc
== sigp_busy
);
211 static void do_store_status(void)
215 /* store status of all processors in their lowcores (real 0) */
216 for_each_online_cpu(cpu
) {
217 if (cpu
== smp_processor_id())
220 rc
= signal_processor_p(
221 (__u32
)(unsigned long) lowcore_ptr
[cpu
], cpu
,
222 sigp_store_status_at_address
);
223 } while(rc
== sigp_busy
);
227 static void do_wait_for_stop(void)
231 /* Wait for all other cpus to enter stopped state */
232 for_each_online_cpu(cpu
) {
233 if (cpu
== smp_processor_id())
235 while(!smp_cpu_not_running(cpu
))
241 * this function sends a 'stop' sigp to all other CPUs in the system.
242 * it goes straight through.
244 void smp_send_stop(void)
246 /* Disable all interrupts/machine checks */
247 __load_psw_mask(psw_kernel_bits
& ~PSW_MASK_MCHECK
);
249 /* write magic number to zero page (absolute 0) */
250 lowcore_ptr
[smp_processor_id()]->panic_magic
= __PANIC_MAGIC
;
252 /* stop other processors. */
255 /* wait until other processors are stopped */
258 /* store status of other processors. */
263 * 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
)
326 * Send an external call sigp to every other cpu in the system and
327 * return without waiting for its completion.
329 static void smp_ext_bitcall_others(ec_bit_sig sig
)
333 for_each_online_cpu(cpu
) {
334 if (cpu
== smp_processor_id())
337 * Set signaling bit in lowcore of target cpu and kick it
339 set_bit(sig
, (unsigned long *) &lowcore_ptr
[cpu
]->ext_call_fast
);
340 while (signal_processor(cpu
, sigp_emergency_signal
) == sigp_busy
)
347 * this function sends a 'purge tlb' signal to another CPU.
349 void smp_ptlb_callback(void *info
)
354 void smp_ptlb_all(void)
356 on_each_cpu(smp_ptlb_callback
, NULL
, 0, 1);
358 EXPORT_SYMBOL(smp_ptlb_all
);
359 #endif /* ! CONFIG_64BIT */
362 * this function sends a 'reschedule' IPI to another CPU.
363 * it goes straight through and wastes no time serializing
364 * anything. Worst case is that we lose a reschedule ...
366 void smp_send_reschedule(int cpu
)
368 smp_ext_bitcall(cpu
, ec_schedule
);
372 * parameter area for the set/clear control bit callbacks
374 struct ec_creg_mask_parms
{
375 unsigned long orvals
[16];
376 unsigned long andvals
[16];
380 * callback for setting/clearing control bits
382 static void smp_ctl_bit_callback(void *info
) {
383 struct ec_creg_mask_parms
*pp
= info
;
384 unsigned long cregs
[16];
387 __ctl_store(cregs
, 0, 15);
388 for (i
= 0; i
<= 15; i
++)
389 cregs
[i
] = (cregs
[i
] & pp
->andvals
[i
]) | pp
->orvals
[i
];
390 __ctl_load(cregs
, 0, 15);
394 * Set a bit in a control register of all cpus
396 void smp_ctl_set_bit(int cr
, int bit
)
398 struct ec_creg_mask_parms parms
;
400 memset(&parms
.orvals
, 0, sizeof(parms
.orvals
));
401 memset(&parms
.andvals
, 0xff, sizeof(parms
.andvals
));
402 parms
.orvals
[cr
] = 1 << bit
;
403 on_each_cpu(smp_ctl_bit_callback
, &parms
, 0, 1);
407 * Clear a bit in a control register of all cpus
409 void smp_ctl_clear_bit(int cr
, int bit
)
411 struct ec_creg_mask_parms parms
;
413 memset(&parms
.orvals
, 0, sizeof(parms
.orvals
));
414 memset(&parms
.andvals
, 0xff, sizeof(parms
.andvals
));
415 parms
.andvals
[cr
] = ~(1L << bit
);
416 on_each_cpu(smp_ctl_bit_callback
, &parms
, 0, 1);
420 * Lets check how many CPUs we have.
424 __init
smp_count_cpus(void)
426 unsigned int cpu
, num_cpus
;
430 * cpu 0 is the boot cpu. See smp_prepare_boot_cpu.
433 boot_cpu_addr
= S390_lowcore
.cpu_data
.cpu_addr
;
434 current_thread_info()->cpu
= 0;
436 for (cpu
= 0; cpu
<= 65535; cpu
++) {
437 if ((__u16
) cpu
== boot_cpu_addr
)
439 __cpu_logical_map
[1] = (__u16
) cpu
;
440 if (signal_processor(1, sigp_sense
) ==
441 sigp_not_operational
)
446 printk("Detected %d CPU's\n",(int) num_cpus
);
447 printk("Boot cpu address %2X\n", boot_cpu_addr
);
453 * Activate a secondary processor.
455 int __devinit
start_secondary(void *cpuvoid
)
460 /* Enable TOD clock interrupts on the secondary cpu. */
462 #ifdef CONFIG_VIRT_TIMER
463 /* Enable cpu timer interrupts on the secondary cpu. */
466 /* Enable pfault pseudo page faults on this cpu. */
469 /* Mark this cpu as online */
470 cpu_set(smp_processor_id(), cpu_online_map
);
471 /* Switch on interrupts */
473 /* Print info about this processor */
474 print_cpu_info(&S390_lowcore
.cpu_data
);
475 /* cpu_idle will call schedule for us */
480 static void __init
smp_create_idle(unsigned int cpu
)
482 struct task_struct
*p
;
485 * don't care about the psw and regs settings since we'll never
486 * reschedule the forked task.
490 panic("failed fork for CPU %u: %li", cpu
, PTR_ERR(p
));
491 current_set
[cpu
] = p
;
494 /* Reserving and releasing of CPUs */
496 static DEFINE_SPINLOCK(smp_reserve_lock
);
497 static int smp_cpu_reserved
[NR_CPUS
];
500 smp_get_cpu(cpumask_t cpu_mask
)
505 spin_lock_irqsave(&smp_reserve_lock
, flags
);
506 /* Try to find an already reserved cpu. */
507 for_each_cpu_mask(cpu
, cpu_mask
) {
508 if (smp_cpu_reserved
[cpu
] != 0) {
509 smp_cpu_reserved
[cpu
]++;
514 /* Reserve a new cpu from cpu_mask. */
515 for_each_cpu_mask(cpu
, cpu_mask
) {
516 if (cpu_online(cpu
)) {
517 smp_cpu_reserved
[cpu
]++;
523 spin_unlock_irqrestore(&smp_reserve_lock
, flags
);
532 spin_lock_irqsave(&smp_reserve_lock
, flags
);
533 smp_cpu_reserved
[cpu
]--;
534 spin_unlock_irqrestore(&smp_reserve_lock
, flags
);
542 /* Check for stopped state */
543 if (signal_processor_ps(&status
, 0, cpu
, sigp_sense
) == sigp_status_stored
) {
550 /* Upping and downing of CPUs */
553 __cpu_up(unsigned int cpu
)
555 struct task_struct
*idle
;
556 struct _lowcore
*cpu_lowcore
;
557 struct stack_frame
*sf
;
561 for (curr_cpu
= 0; curr_cpu
<= 65535; curr_cpu
++) {
562 __cpu_logical_map
[cpu
] = (__u16
) curr_cpu
;
563 if (cpu_stopped(cpu
))
567 if (!cpu_stopped(cpu
))
570 ccode
= signal_processor_p((__u32
)(unsigned long)(lowcore_ptr
[cpu
]),
571 cpu
, sigp_set_prefix
);
573 printk("sigp_set_prefix failed for cpu %d "
574 "with condition code %d\n",
575 (int) cpu
, (int) ccode
);
579 idle
= current_set
[cpu
];
580 cpu_lowcore
= lowcore_ptr
[cpu
];
581 cpu_lowcore
->kernel_stack
= (unsigned long)
582 task_stack_page(idle
) + (THREAD_SIZE
);
583 sf
= (struct stack_frame
*) (cpu_lowcore
->kernel_stack
584 - sizeof(struct pt_regs
)
585 - sizeof(struct stack_frame
));
586 memset(sf
, 0, sizeof(struct stack_frame
));
587 sf
->gprs
[9] = (unsigned long) sf
;
588 cpu_lowcore
->save_area
[15] = (unsigned long) sf
;
589 __ctl_store(cpu_lowcore
->cregs_save_area
[0], 0, 15);
592 : : "a" (&cpu_lowcore
->access_regs_save_area
) : "memory");
593 cpu_lowcore
->percpu_offset
= __per_cpu_offset
[cpu
];
594 cpu_lowcore
->current_task
= (unsigned long) idle
;
595 cpu_lowcore
->cpu_data
.cpu_nr
= cpu
;
598 while (signal_processor(cpu
,sigp_restart
) == sigp_busy
)
601 while (!cpu_online(cpu
))
606 static unsigned int __initdata additional_cpus
;
607 static unsigned int __initdata possible_cpus
;
609 void __init
smp_setup_cpu_possible_map(void)
611 unsigned int phy_cpus
, pos_cpus
, cpu
;
613 phy_cpus
= smp_count_cpus();
614 pos_cpus
= min(phy_cpus
+ additional_cpus
, (unsigned int) NR_CPUS
);
617 pos_cpus
= min(possible_cpus
, (unsigned int) NR_CPUS
);
619 for (cpu
= 0; cpu
< pos_cpus
; cpu
++)
620 cpu_set(cpu
, cpu_possible_map
);
622 phy_cpus
= min(phy_cpus
, pos_cpus
);
624 for (cpu
= 0; cpu
< phy_cpus
; cpu
++)
625 cpu_set(cpu
, cpu_present_map
);
628 #ifdef CONFIG_HOTPLUG_CPU
630 static int __init
setup_additional_cpus(char *s
)
632 additional_cpus
= simple_strtoul(s
, NULL
, 0);
635 early_param("additional_cpus", setup_additional_cpus
);
637 static int __init
setup_possible_cpus(char *s
)
639 possible_cpus
= simple_strtoul(s
, NULL
, 0);
642 early_param("possible_cpus", setup_possible_cpus
);
648 struct ec_creg_mask_parms cr_parms
;
649 int cpu
= smp_processor_id();
651 spin_lock_irqsave(&smp_reserve_lock
, flags
);
652 if (smp_cpu_reserved
[cpu
] != 0) {
653 spin_unlock_irqrestore(&smp_reserve_lock
, flags
);
656 cpu_clear(cpu
, cpu_online_map
);
658 /* Disable pfault pseudo page faults on this cpu. */
661 memset(&cr_parms
.orvals
, 0, sizeof(cr_parms
.orvals
));
662 memset(&cr_parms
.andvals
, 0xff, sizeof(cr_parms
.andvals
));
664 /* disable all external interrupts */
665 cr_parms
.orvals
[0] = 0;
666 cr_parms
.andvals
[0] = ~(1<<15 | 1<<14 | 1<<13 | 1<<12 |
667 1<<11 | 1<<10 | 1<< 6 | 1<< 4);
668 /* disable all I/O interrupts */
669 cr_parms
.orvals
[6] = 0;
670 cr_parms
.andvals
[6] = ~(1<<31 | 1<<30 | 1<<29 | 1<<28 |
671 1<<27 | 1<<26 | 1<<25 | 1<<24);
672 /* disable most machine checks */
673 cr_parms
.orvals
[14] = 0;
674 cr_parms
.andvals
[14] = ~(1<<28 | 1<<27 | 1<<26 | 1<<25 | 1<<24);
676 smp_ctl_bit_callback(&cr_parms
);
678 spin_unlock_irqrestore(&smp_reserve_lock
, flags
);
683 __cpu_die(unsigned int cpu
)
685 /* Wait until target cpu is down */
686 while (!smp_cpu_not_running(cpu
))
688 printk("Processor %d spun down\n", cpu
);
695 signal_processor(smp_processor_id(), sigp_stop
);
700 #endif /* CONFIG_HOTPLUG_CPU */
703 * Cycle through the processors and setup structures.
706 void __init
smp_prepare_cpus(unsigned int max_cpus
)
712 /* request the 0x1201 emergency signal external interrupt */
713 if (register_external_interrupt(0x1201, do_ext_call_interrupt
) != 0)
714 panic("Couldn't request external interrupt 0x1201");
715 memset(lowcore_ptr
,0,sizeof(lowcore_ptr
));
717 * Initialize prefix pages and stacks for all possible cpus
719 print_cpu_info(&S390_lowcore
.cpu_data
);
721 for_each_possible_cpu(i
) {
722 lowcore_ptr
[i
] = (struct _lowcore
*)
723 __get_free_pages(GFP_KERNEL
|GFP_DMA
,
724 sizeof(void*) == 8 ? 1 : 0);
725 stack
= __get_free_pages(GFP_KERNEL
,ASYNC_ORDER
);
726 if (lowcore_ptr
[i
] == NULL
|| stack
== 0ULL)
727 panic("smp_boot_cpus failed to allocate memory\n");
729 *(lowcore_ptr
[i
]) = S390_lowcore
;
730 lowcore_ptr
[i
]->async_stack
= stack
+ (ASYNC_SIZE
);
731 stack
= __get_free_pages(GFP_KERNEL
,0);
733 panic("smp_boot_cpus failed to allocate memory\n");
734 lowcore_ptr
[i
]->panic_stack
= stack
+ (PAGE_SIZE
);
736 if (MACHINE_HAS_IEEE
) {
737 lowcore_ptr
[i
]->extended_save_area_addr
=
738 (__u32
) __get_free_pages(GFP_KERNEL
,0);
739 if (lowcore_ptr
[i
]->extended_save_area_addr
== 0)
740 panic("smp_boot_cpus failed to "
741 "allocate memory\n");
746 if (MACHINE_HAS_IEEE
)
747 ctl_set_bit(14, 29); /* enable extended save area */
749 set_prefix((u32
)(unsigned long) lowcore_ptr
[smp_processor_id()]);
751 for_each_possible_cpu(cpu
)
752 if (cpu
!= smp_processor_id())
753 smp_create_idle(cpu
);
756 void __devinit
smp_prepare_boot_cpu(void)
758 BUG_ON(smp_processor_id() != 0);
760 cpu_set(0, cpu_online_map
);
761 S390_lowcore
.percpu_offset
= __per_cpu_offset
[0];
762 current_set
[0] = current
;
765 void smp_cpus_done(unsigned int max_cpus
)
767 cpu_present_map
= cpu_possible_map
;
771 * the frequency of the profiling timer can be changed
772 * by writing a multiplier value into /proc/profile.
774 * usually you want to run this on all CPUs ;)
776 int setup_profiling_timer(unsigned int multiplier
)
781 static DEFINE_PER_CPU(struct cpu
, cpu_devices
);
783 static int __init
topology_init(void)
788 for_each_possible_cpu(cpu
) {
789 struct cpu
*c
= &per_cpu(cpu_devices
, cpu
);
792 ret
= register_cpu(c
, cpu
);
794 printk(KERN_WARNING
"topology_init: register_cpu %d "
795 "failed (%d)\n", cpu
, ret
);
800 subsys_initcall(topology_init
);
802 EXPORT_SYMBOL(cpu_online_map
);
803 EXPORT_SYMBOL(cpu_possible_map
);
804 EXPORT_SYMBOL(lowcore_ptr
);
805 EXPORT_SYMBOL(smp_ctl_set_bit
);
806 EXPORT_SYMBOL(smp_ctl_clear_bit
);
807 EXPORT_SYMBOL(smp_call_function
);
808 EXPORT_SYMBOL(smp_get_cpu
);
809 EXPORT_SYMBOL(smp_put_cpu
);