Merge branch 'for-3.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
[linux/fpc-iii.git] / arch / alpha / kernel / smp.c
blob9603bc234b479ce8ffbbbc961f8c0df9da97fff4
1 /*
2 * linux/arch/alpha/kernel/smp.c
4 * 2001-07-09 Phil Ezolt (Phillip.Ezolt@compaq.com)
5 * Renamed modified smp_call_function to smp_call_function_on_cpu()
6 * Created an function that conforms to the old calling convention
7 * of smp_call_function().
9 * This is helpful for DCPI.
13 #include <linux/errno.h>
14 #include <linux/kernel.h>
15 #include <linux/kernel_stat.h>
16 #include <linux/module.h>
17 #include <linux/sched.h>
18 #include <linux/mm.h>
19 #include <linux/err.h>
20 #include <linux/threads.h>
21 #include <linux/smp.h>
22 #include <linux/interrupt.h>
23 #include <linux/init.h>
24 #include <linux/delay.h>
25 #include <linux/spinlock.h>
26 #include <linux/irq.h>
27 #include <linux/cache.h>
28 #include <linux/profile.h>
29 #include <linux/bitops.h>
30 #include <linux/cpu.h>
32 #include <asm/hwrpb.h>
33 #include <asm/ptrace.h>
34 #include <linux/atomic.h>
36 #include <asm/io.h>
37 #include <asm/irq.h>
38 #include <asm/pgtable.h>
39 #include <asm/pgalloc.h>
40 #include <asm/mmu_context.h>
41 #include <asm/tlbflush.h>
43 #include "proto.h"
44 #include "irq_impl.h"
47 #define DEBUG_SMP 0
48 #if DEBUG_SMP
49 #define DBGS(args) printk args
50 #else
51 #define DBGS(args)
52 #endif
54 /* A collection of per-processor data. */
55 struct cpuinfo_alpha cpu_data[NR_CPUS];
56 EXPORT_SYMBOL(cpu_data);
58 /* A collection of single bit ipi messages. */
59 static struct {
60 unsigned long bits ____cacheline_aligned;
61 } ipi_data[NR_CPUS] __cacheline_aligned;
63 enum ipi_message_type {
64 IPI_RESCHEDULE,
65 IPI_CALL_FUNC,
66 IPI_CALL_FUNC_SINGLE,
67 IPI_CPU_STOP,
70 /* Set to a secondary's cpuid when it comes online. */
71 static int smp_secondary_alive = 0;
73 int smp_num_probed; /* Internal processor count */
74 int smp_num_cpus = 1; /* Number that came online. */
75 EXPORT_SYMBOL(smp_num_cpus);
78 * Called by both boot and secondaries to move global data into
79 * per-processor storage.
81 static inline void __init
82 smp_store_cpu_info(int cpuid)
84 cpu_data[cpuid].loops_per_jiffy = loops_per_jiffy;
85 cpu_data[cpuid].last_asn = ASN_FIRST_VERSION;
86 cpu_data[cpuid].need_new_asn = 0;
87 cpu_data[cpuid].asn_lock = 0;
91 * Ideally sets up per-cpu profiling hooks. Doesn't do much now...
93 static inline void __init
94 smp_setup_percpu_timer(int cpuid)
96 cpu_data[cpuid].prof_counter = 1;
97 cpu_data[cpuid].prof_multiplier = 1;
100 static void __init
101 wait_boot_cpu_to_stop(int cpuid)
103 unsigned long stop = jiffies + 10*HZ;
105 while (time_before(jiffies, stop)) {
106 if (!smp_secondary_alive)
107 return;
108 barrier();
111 printk("wait_boot_cpu_to_stop: FAILED on CPU %d, hanging now\n", cpuid);
112 for (;;)
113 barrier();
117 * Where secondaries begin a life of C.
119 void __cpuinit
120 smp_callin(void)
122 int cpuid = hard_smp_processor_id();
124 if (cpu_online(cpuid)) {
125 printk("??, cpu 0x%x already present??\n", cpuid);
126 BUG();
128 set_cpu_online(cpuid, true);
130 /* Turn on machine checks. */
131 wrmces(7);
133 /* Set trap vectors. */
134 trap_init();
136 /* Set interrupt vector. */
137 wrent(entInt, 0);
139 /* Get our local ticker going. */
140 smp_setup_percpu_timer(cpuid);
142 /* Call platform-specific callin, if specified */
143 if (alpha_mv.smp_callin) alpha_mv.smp_callin();
145 /* All kernel threads share the same mm context. */
146 atomic_inc(&init_mm.mm_count);
147 current->active_mm = &init_mm;
149 /* inform the notifiers about the new cpu */
150 notify_cpu_starting(cpuid);
152 /* Must have completely accurate bogos. */
153 local_irq_enable();
155 /* Wait boot CPU to stop with irq enabled before running
156 calibrate_delay. */
157 wait_boot_cpu_to_stop(cpuid);
158 mb();
159 calibrate_delay();
161 smp_store_cpu_info(cpuid);
162 /* Allow master to continue only after we written loops_per_jiffy. */
163 wmb();
164 smp_secondary_alive = 1;
166 DBGS(("smp_callin: commencing CPU %d current %p active_mm %p\n",
167 cpuid, current, current->active_mm));
169 preempt_disable();
170 /* Do nothing. */
171 cpu_idle();
174 /* Wait until hwrpb->txrdy is clear for cpu. Return -1 on timeout. */
175 static int
176 wait_for_txrdy (unsigned long cpumask)
178 unsigned long timeout;
180 if (!(hwrpb->txrdy & cpumask))
181 return 0;
183 timeout = jiffies + 10*HZ;
184 while (time_before(jiffies, timeout)) {
185 if (!(hwrpb->txrdy & cpumask))
186 return 0;
187 udelay(10);
188 barrier();
191 return -1;
195 * Send a message to a secondary's console. "START" is one such
196 * interesting message. ;-)
198 static void __cpuinit
199 send_secondary_console_msg(char *str, int cpuid)
201 struct percpu_struct *cpu;
202 register char *cp1, *cp2;
203 unsigned long cpumask;
204 size_t len;
206 cpu = (struct percpu_struct *)
207 ((char*)hwrpb
208 + hwrpb->processor_offset
209 + cpuid * hwrpb->processor_size);
211 cpumask = (1UL << cpuid);
212 if (wait_for_txrdy(cpumask))
213 goto timeout;
215 cp2 = str;
216 len = strlen(cp2);
217 *(unsigned int *)&cpu->ipc_buffer[0] = len;
218 cp1 = (char *) &cpu->ipc_buffer[1];
219 memcpy(cp1, cp2, len);
221 /* atomic test and set */
222 wmb();
223 set_bit(cpuid, &hwrpb->rxrdy);
225 if (wait_for_txrdy(cpumask))
226 goto timeout;
227 return;
229 timeout:
230 printk("Processor %x not ready\n", cpuid);
234 * A secondary console wants to send a message. Receive it.
236 static void
237 recv_secondary_console_msg(void)
239 int mycpu, i, cnt;
240 unsigned long txrdy = hwrpb->txrdy;
241 char *cp1, *cp2, buf[80];
242 struct percpu_struct *cpu;
244 DBGS(("recv_secondary_console_msg: TXRDY 0x%lx.\n", txrdy));
246 mycpu = hard_smp_processor_id();
248 for (i = 0; i < NR_CPUS; i++) {
249 if (!(txrdy & (1UL << i)))
250 continue;
252 DBGS(("recv_secondary_console_msg: "
253 "TXRDY contains CPU %d.\n", i));
255 cpu = (struct percpu_struct *)
256 ((char*)hwrpb
257 + hwrpb->processor_offset
258 + i * hwrpb->processor_size);
260 DBGS(("recv_secondary_console_msg: on %d from %d"
261 " HALT_REASON 0x%lx FLAGS 0x%lx\n",
262 mycpu, i, cpu->halt_reason, cpu->flags));
264 cnt = cpu->ipc_buffer[0] >> 32;
265 if (cnt <= 0 || cnt >= 80)
266 strcpy(buf, "<<< BOGUS MSG >>>");
267 else {
268 cp1 = (char *) &cpu->ipc_buffer[11];
269 cp2 = buf;
270 strcpy(cp2, cp1);
272 while ((cp2 = strchr(cp2, '\r')) != 0) {
273 *cp2 = ' ';
274 if (cp2[1] == '\n')
275 cp2[1] = ' ';
279 DBGS((KERN_INFO "recv_secondary_console_msg: on %d "
280 "message is '%s'\n", mycpu, buf));
283 hwrpb->txrdy = 0;
287 * Convince the console to have a secondary cpu begin execution.
289 static int __cpuinit
290 secondary_cpu_start(int cpuid, struct task_struct *idle)
292 struct percpu_struct *cpu;
293 struct pcb_struct *hwpcb, *ipcb;
294 unsigned long timeout;
296 cpu = (struct percpu_struct *)
297 ((char*)hwrpb
298 + hwrpb->processor_offset
299 + cpuid * hwrpb->processor_size);
300 hwpcb = (struct pcb_struct *) cpu->hwpcb;
301 ipcb = &task_thread_info(idle)->pcb;
303 /* Initialize the CPU's HWPCB to something just good enough for
304 us to get started. Immediately after starting, we'll swpctx
305 to the target idle task's pcb. Reuse the stack in the mean
306 time. Precalculate the target PCBB. */
307 hwpcb->ksp = (unsigned long)ipcb + sizeof(union thread_union) - 16;
308 hwpcb->usp = 0;
309 hwpcb->ptbr = ipcb->ptbr;
310 hwpcb->pcc = 0;
311 hwpcb->asn = 0;
312 hwpcb->unique = virt_to_phys(ipcb);
313 hwpcb->flags = ipcb->flags;
314 hwpcb->res1 = hwpcb->res2 = 0;
316 #if 0
317 DBGS(("KSP 0x%lx PTBR 0x%lx VPTBR 0x%lx UNIQUE 0x%lx\n",
318 hwpcb->ksp, hwpcb->ptbr, hwrpb->vptb, hwpcb->unique));
319 #endif
320 DBGS(("Starting secondary cpu %d: state 0x%lx pal_flags 0x%lx\n",
321 cpuid, idle->state, ipcb->flags));
323 /* Setup HWRPB fields that SRM uses to activate secondary CPU */
324 hwrpb->CPU_restart = __smp_callin;
325 hwrpb->CPU_restart_data = (unsigned long) __smp_callin;
327 /* Recalculate and update the HWRPB checksum */
328 hwrpb_update_checksum(hwrpb);
331 * Send a "start" command to the specified processor.
334 /* SRM III 3.4.1.3 */
335 cpu->flags |= 0x22; /* turn on Context Valid and Restart Capable */
336 cpu->flags &= ~1; /* turn off Bootstrap In Progress */
337 wmb();
339 send_secondary_console_msg("START\r\n", cpuid);
341 /* Wait 10 seconds for an ACK from the console. */
342 timeout = jiffies + 10*HZ;
343 while (time_before(jiffies, timeout)) {
344 if (cpu->flags & 1)
345 goto started;
346 udelay(10);
347 barrier();
349 printk(KERN_ERR "SMP: Processor %d failed to start.\n", cpuid);
350 return -1;
352 started:
353 DBGS(("secondary_cpu_start: SUCCESS for CPU %d!!!\n", cpuid));
354 return 0;
358 * Bring one cpu online.
360 static int __cpuinit
361 smp_boot_one_cpu(int cpuid, struct task_struct *idle)
363 unsigned long timeout;
365 /* Signal the secondary to wait a moment. */
366 smp_secondary_alive = -1;
368 /* Whirrr, whirrr, whirrrrrrrrr... */
369 if (secondary_cpu_start(cpuid, idle))
370 return -1;
372 /* Notify the secondary CPU it can run calibrate_delay. */
373 mb();
374 smp_secondary_alive = 0;
376 /* We've been acked by the console; wait one second for
377 the task to start up for real. */
378 timeout = jiffies + 1*HZ;
379 while (time_before(jiffies, timeout)) {
380 if (smp_secondary_alive == 1)
381 goto alive;
382 udelay(10);
383 barrier();
386 /* We failed to boot the CPU. */
388 printk(KERN_ERR "SMP: Processor %d is stuck.\n", cpuid);
389 return -1;
391 alive:
392 /* Another "Red Snapper". */
393 return 0;
397 * Called from setup_arch. Detect an SMP system and which processors
398 * are present.
400 void __init
401 setup_smp(void)
403 struct percpu_struct *cpubase, *cpu;
404 unsigned long i;
406 if (boot_cpuid != 0) {
407 printk(KERN_WARNING "SMP: Booting off cpu %d instead of 0?\n",
408 boot_cpuid);
411 if (hwrpb->nr_processors > 1) {
412 int boot_cpu_palrev;
414 DBGS(("setup_smp: nr_processors %ld\n",
415 hwrpb->nr_processors));
417 cpubase = (struct percpu_struct *)
418 ((char*)hwrpb + hwrpb->processor_offset);
419 boot_cpu_palrev = cpubase->pal_revision;
421 for (i = 0; i < hwrpb->nr_processors; i++) {
422 cpu = (struct percpu_struct *)
423 ((char *)cpubase + i*hwrpb->processor_size);
424 if ((cpu->flags & 0x1cc) == 0x1cc) {
425 smp_num_probed++;
426 set_cpu_possible(i, true);
427 set_cpu_present(i, true);
428 cpu->pal_revision = boot_cpu_palrev;
431 DBGS(("setup_smp: CPU %d: flags 0x%lx type 0x%lx\n",
432 i, cpu->flags, cpu->type));
433 DBGS(("setup_smp: CPU %d: PAL rev 0x%lx\n",
434 i, cpu->pal_revision));
436 } else {
437 smp_num_probed = 1;
440 printk(KERN_INFO "SMP: %d CPUs probed -- cpu_present_mask = %lx\n",
441 smp_num_probed, cpumask_bits(cpu_present_mask)[0]);
445 * Called by smp_init prepare the secondaries
447 void __init
448 smp_prepare_cpus(unsigned int max_cpus)
450 /* Take care of some initial bookkeeping. */
451 memset(ipi_data, 0, sizeof(ipi_data));
453 current_thread_info()->cpu = boot_cpuid;
455 smp_store_cpu_info(boot_cpuid);
456 smp_setup_percpu_timer(boot_cpuid);
458 /* Nothing to do on a UP box, or when told not to. */
459 if (smp_num_probed == 1 || max_cpus == 0) {
460 init_cpu_possible(cpumask_of(boot_cpuid));
461 init_cpu_present(cpumask_of(boot_cpuid));
462 printk(KERN_INFO "SMP mode deactivated.\n");
463 return;
466 printk(KERN_INFO "SMP starting up secondaries.\n");
468 smp_num_cpus = smp_num_probed;
471 void
472 smp_prepare_boot_cpu(void)
476 int __cpuinit
477 __cpu_up(unsigned int cpu, struct task_struct *tidle)
479 smp_boot_one_cpu(cpu, tidle);
481 return cpu_online(cpu) ? 0 : -ENOSYS;
484 void __init
485 smp_cpus_done(unsigned int max_cpus)
487 int cpu;
488 unsigned long bogosum = 0;
490 for(cpu = 0; cpu < NR_CPUS; cpu++)
491 if (cpu_online(cpu))
492 bogosum += cpu_data[cpu].loops_per_jiffy;
494 printk(KERN_INFO "SMP: Total of %d processors activated "
495 "(%lu.%02lu BogoMIPS).\n",
496 num_online_cpus(),
497 (bogosum + 2500) / (500000/HZ),
498 ((bogosum + 2500) / (5000/HZ)) % 100);
502 void
503 smp_percpu_timer_interrupt(struct pt_regs *regs)
505 struct pt_regs *old_regs;
506 int cpu = smp_processor_id();
507 unsigned long user = user_mode(regs);
508 struct cpuinfo_alpha *data = &cpu_data[cpu];
510 old_regs = set_irq_regs(regs);
512 /* Record kernel PC. */
513 profile_tick(CPU_PROFILING);
515 if (!--data->prof_counter) {
516 /* We need to make like a normal interrupt -- otherwise
517 timer interrupts ignore the global interrupt lock,
518 which would be a Bad Thing. */
519 irq_enter();
521 update_process_times(user);
523 data->prof_counter = data->prof_multiplier;
525 irq_exit();
527 set_irq_regs(old_regs);
531 setup_profiling_timer(unsigned int multiplier)
533 return -EINVAL;
537 static void
538 send_ipi_message(const struct cpumask *to_whom, enum ipi_message_type operation)
540 int i;
542 mb();
543 for_each_cpu(i, to_whom)
544 set_bit(operation, &ipi_data[i].bits);
546 mb();
547 for_each_cpu(i, to_whom)
548 wripir(i);
551 void
552 handle_ipi(struct pt_regs *regs)
554 int this_cpu = smp_processor_id();
555 unsigned long *pending_ipis = &ipi_data[this_cpu].bits;
556 unsigned long ops;
558 #if 0
559 DBGS(("handle_ipi: on CPU %d ops 0x%lx PC 0x%lx\n",
560 this_cpu, *pending_ipis, regs->pc));
561 #endif
563 mb(); /* Order interrupt and bit testing. */
564 while ((ops = xchg(pending_ipis, 0)) != 0) {
565 mb(); /* Order bit clearing and data access. */
566 do {
567 unsigned long which;
569 which = ops & -ops;
570 ops &= ~which;
571 which = __ffs(which);
573 switch (which) {
574 case IPI_RESCHEDULE:
575 scheduler_ipi();
576 break;
578 case IPI_CALL_FUNC:
579 generic_smp_call_function_interrupt();
580 break;
582 case IPI_CALL_FUNC_SINGLE:
583 generic_smp_call_function_single_interrupt();
584 break;
586 case IPI_CPU_STOP:
587 halt();
589 default:
590 printk(KERN_CRIT "Unknown IPI on CPU %d: %lu\n",
591 this_cpu, which);
592 break;
594 } while (ops);
596 mb(); /* Order data access and bit testing. */
599 cpu_data[this_cpu].ipi_count++;
601 if (hwrpb->txrdy)
602 recv_secondary_console_msg();
605 void
606 smp_send_reschedule(int cpu)
608 #ifdef DEBUG_IPI_MSG
609 if (cpu == hard_smp_processor_id())
610 printk(KERN_WARNING
611 "smp_send_reschedule: Sending IPI to self.\n");
612 #endif
613 send_ipi_message(cpumask_of(cpu), IPI_RESCHEDULE);
616 void
617 smp_send_stop(void)
619 cpumask_t to_whom;
620 cpumask_copy(&to_whom, cpu_possible_mask);
621 cpumask_clear_cpu(smp_processor_id(), &to_whom);
622 #ifdef DEBUG_IPI_MSG
623 if (hard_smp_processor_id() != boot_cpu_id)
624 printk(KERN_WARNING "smp_send_stop: Not on boot cpu.\n");
625 #endif
626 send_ipi_message(&to_whom, IPI_CPU_STOP);
629 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
631 send_ipi_message(mask, IPI_CALL_FUNC);
634 void arch_send_call_function_single_ipi(int cpu)
636 send_ipi_message(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE);
639 static void
640 ipi_imb(void *ignored)
642 imb();
645 void
646 smp_imb(void)
648 /* Must wait other processors to flush their icache before continue. */
649 if (on_each_cpu(ipi_imb, NULL, 1))
650 printk(KERN_CRIT "smp_imb: timed out\n");
652 EXPORT_SYMBOL(smp_imb);
654 static void
655 ipi_flush_tlb_all(void *ignored)
657 tbia();
660 void
661 flush_tlb_all(void)
663 /* Although we don't have any data to pass, we do want to
664 synchronize with the other processors. */
665 if (on_each_cpu(ipi_flush_tlb_all, NULL, 1)) {
666 printk(KERN_CRIT "flush_tlb_all: timed out\n");
670 #define asn_locked() (cpu_data[smp_processor_id()].asn_lock)
672 static void
673 ipi_flush_tlb_mm(void *x)
675 struct mm_struct *mm = (struct mm_struct *) x;
676 if (mm == current->active_mm && !asn_locked())
677 flush_tlb_current(mm);
678 else
679 flush_tlb_other(mm);
682 void
683 flush_tlb_mm(struct mm_struct *mm)
685 preempt_disable();
687 if (mm == current->active_mm) {
688 flush_tlb_current(mm);
689 if (atomic_read(&mm->mm_users) <= 1) {
690 int cpu, this_cpu = smp_processor_id();
691 for (cpu = 0; cpu < NR_CPUS; cpu++) {
692 if (!cpu_online(cpu) || cpu == this_cpu)
693 continue;
694 if (mm->context[cpu])
695 mm->context[cpu] = 0;
697 preempt_enable();
698 return;
702 if (smp_call_function(ipi_flush_tlb_mm, mm, 1)) {
703 printk(KERN_CRIT "flush_tlb_mm: timed out\n");
706 preempt_enable();
708 EXPORT_SYMBOL(flush_tlb_mm);
710 struct flush_tlb_page_struct {
711 struct vm_area_struct *vma;
712 struct mm_struct *mm;
713 unsigned long addr;
716 static void
717 ipi_flush_tlb_page(void *x)
719 struct flush_tlb_page_struct *data = (struct flush_tlb_page_struct *)x;
720 struct mm_struct * mm = data->mm;
722 if (mm == current->active_mm && !asn_locked())
723 flush_tlb_current_page(mm, data->vma, data->addr);
724 else
725 flush_tlb_other(mm);
728 void
729 flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)
731 struct flush_tlb_page_struct data;
732 struct mm_struct *mm = vma->vm_mm;
734 preempt_disable();
736 if (mm == current->active_mm) {
737 flush_tlb_current_page(mm, vma, addr);
738 if (atomic_read(&mm->mm_users) <= 1) {
739 int cpu, this_cpu = smp_processor_id();
740 for (cpu = 0; cpu < NR_CPUS; cpu++) {
741 if (!cpu_online(cpu) || cpu == this_cpu)
742 continue;
743 if (mm->context[cpu])
744 mm->context[cpu] = 0;
746 preempt_enable();
747 return;
751 data.vma = vma;
752 data.mm = mm;
753 data.addr = addr;
755 if (smp_call_function(ipi_flush_tlb_page, &data, 1)) {
756 printk(KERN_CRIT "flush_tlb_page: timed out\n");
759 preempt_enable();
761 EXPORT_SYMBOL(flush_tlb_page);
763 void
764 flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
766 /* On the Alpha we always flush the whole user tlb. */
767 flush_tlb_mm(vma->vm_mm);
769 EXPORT_SYMBOL(flush_tlb_range);
771 static void
772 ipi_flush_icache_page(void *x)
774 struct mm_struct *mm = (struct mm_struct *) x;
775 if (mm == current->active_mm && !asn_locked())
776 __load_new_mm_context(mm);
777 else
778 flush_tlb_other(mm);
781 void
782 flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
783 unsigned long addr, int len)
785 struct mm_struct *mm = vma->vm_mm;
787 if ((vma->vm_flags & VM_EXEC) == 0)
788 return;
790 preempt_disable();
792 if (mm == current->active_mm) {
793 __load_new_mm_context(mm);
794 if (atomic_read(&mm->mm_users) <= 1) {
795 int cpu, this_cpu = smp_processor_id();
796 for (cpu = 0; cpu < NR_CPUS; cpu++) {
797 if (!cpu_online(cpu) || cpu == this_cpu)
798 continue;
799 if (mm->context[cpu])
800 mm->context[cpu] = 0;
802 preempt_enable();
803 return;
807 if (smp_call_function(ipi_flush_icache_page, mm, 1)) {
808 printk(KERN_CRIT "flush_icache_page: timed out\n");
811 preempt_enable();