Merge tag 'soc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
[linux-2.6.git] / arch / alpha / kernel / smp.c
blob7b60834fb4b2f3e2b638c1cb6c73f6f179ef0752
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 cpu_startup_entry(CPUHP_ONLINE);
173 /* Wait until hwrpb->txrdy is clear for cpu. Return -1 on timeout. */
174 static int
175 wait_for_txrdy (unsigned long cpumask)
177 unsigned long timeout;
179 if (!(hwrpb->txrdy & cpumask))
180 return 0;
182 timeout = jiffies + 10*HZ;
183 while (time_before(jiffies, timeout)) {
184 if (!(hwrpb->txrdy & cpumask))
185 return 0;
186 udelay(10);
187 barrier();
190 return -1;
194 * Send a message to a secondary's console. "START" is one such
195 * interesting message. ;-)
197 static void __cpuinit
198 send_secondary_console_msg(char *str, int cpuid)
200 struct percpu_struct *cpu;
201 register char *cp1, *cp2;
202 unsigned long cpumask;
203 size_t len;
205 cpu = (struct percpu_struct *)
206 ((char*)hwrpb
207 + hwrpb->processor_offset
208 + cpuid * hwrpb->processor_size);
210 cpumask = (1UL << cpuid);
211 if (wait_for_txrdy(cpumask))
212 goto timeout;
214 cp2 = str;
215 len = strlen(cp2);
216 *(unsigned int *)&cpu->ipc_buffer[0] = len;
217 cp1 = (char *) &cpu->ipc_buffer[1];
218 memcpy(cp1, cp2, len);
220 /* atomic test and set */
221 wmb();
222 set_bit(cpuid, &hwrpb->rxrdy);
224 if (wait_for_txrdy(cpumask))
225 goto timeout;
226 return;
228 timeout:
229 printk("Processor %x not ready\n", cpuid);
233 * A secondary console wants to send a message. Receive it.
235 static void
236 recv_secondary_console_msg(void)
238 int mycpu, i, cnt;
239 unsigned long txrdy = hwrpb->txrdy;
240 char *cp1, *cp2, buf[80];
241 struct percpu_struct *cpu;
243 DBGS(("recv_secondary_console_msg: TXRDY 0x%lx.\n", txrdy));
245 mycpu = hard_smp_processor_id();
247 for (i = 0; i < NR_CPUS; i++) {
248 if (!(txrdy & (1UL << i)))
249 continue;
251 DBGS(("recv_secondary_console_msg: "
252 "TXRDY contains CPU %d.\n", i));
254 cpu = (struct percpu_struct *)
255 ((char*)hwrpb
256 + hwrpb->processor_offset
257 + i * hwrpb->processor_size);
259 DBGS(("recv_secondary_console_msg: on %d from %d"
260 " HALT_REASON 0x%lx FLAGS 0x%lx\n",
261 mycpu, i, cpu->halt_reason, cpu->flags));
263 cnt = cpu->ipc_buffer[0] >> 32;
264 if (cnt <= 0 || cnt >= 80)
265 strcpy(buf, "<<< BOGUS MSG >>>");
266 else {
267 cp1 = (char *) &cpu->ipc_buffer[11];
268 cp2 = buf;
269 strcpy(cp2, cp1);
271 while ((cp2 = strchr(cp2, '\r')) != 0) {
272 *cp2 = ' ';
273 if (cp2[1] == '\n')
274 cp2[1] = ' ';
278 DBGS((KERN_INFO "recv_secondary_console_msg: on %d "
279 "message is '%s'\n", mycpu, buf));
282 hwrpb->txrdy = 0;
286 * Convince the console to have a secondary cpu begin execution.
288 static int __cpuinit
289 secondary_cpu_start(int cpuid, struct task_struct *idle)
291 struct percpu_struct *cpu;
292 struct pcb_struct *hwpcb, *ipcb;
293 unsigned long timeout;
295 cpu = (struct percpu_struct *)
296 ((char*)hwrpb
297 + hwrpb->processor_offset
298 + cpuid * hwrpb->processor_size);
299 hwpcb = (struct pcb_struct *) cpu->hwpcb;
300 ipcb = &task_thread_info(idle)->pcb;
302 /* Initialize the CPU's HWPCB to something just good enough for
303 us to get started. Immediately after starting, we'll swpctx
304 to the target idle task's pcb. Reuse the stack in the mean
305 time. Precalculate the target PCBB. */
306 hwpcb->ksp = (unsigned long)ipcb + sizeof(union thread_union) - 16;
307 hwpcb->usp = 0;
308 hwpcb->ptbr = ipcb->ptbr;
309 hwpcb->pcc = 0;
310 hwpcb->asn = 0;
311 hwpcb->unique = virt_to_phys(ipcb);
312 hwpcb->flags = ipcb->flags;
313 hwpcb->res1 = hwpcb->res2 = 0;
315 #if 0
316 DBGS(("KSP 0x%lx PTBR 0x%lx VPTBR 0x%lx UNIQUE 0x%lx\n",
317 hwpcb->ksp, hwpcb->ptbr, hwrpb->vptb, hwpcb->unique));
318 #endif
319 DBGS(("Starting secondary cpu %d: state 0x%lx pal_flags 0x%lx\n",
320 cpuid, idle->state, ipcb->flags));
322 /* Setup HWRPB fields that SRM uses to activate secondary CPU */
323 hwrpb->CPU_restart = __smp_callin;
324 hwrpb->CPU_restart_data = (unsigned long) __smp_callin;
326 /* Recalculate and update the HWRPB checksum */
327 hwrpb_update_checksum(hwrpb);
330 * Send a "start" command to the specified processor.
333 /* SRM III 3.4.1.3 */
334 cpu->flags |= 0x22; /* turn on Context Valid and Restart Capable */
335 cpu->flags &= ~1; /* turn off Bootstrap In Progress */
336 wmb();
338 send_secondary_console_msg("START\r\n", cpuid);
340 /* Wait 10 seconds for an ACK from the console. */
341 timeout = jiffies + 10*HZ;
342 while (time_before(jiffies, timeout)) {
343 if (cpu->flags & 1)
344 goto started;
345 udelay(10);
346 barrier();
348 printk(KERN_ERR "SMP: Processor %d failed to start.\n", cpuid);
349 return -1;
351 started:
352 DBGS(("secondary_cpu_start: SUCCESS for CPU %d!!!\n", cpuid));
353 return 0;
357 * Bring one cpu online.
359 static int __cpuinit
360 smp_boot_one_cpu(int cpuid, struct task_struct *idle)
362 unsigned long timeout;
364 /* Signal the secondary to wait a moment. */
365 smp_secondary_alive = -1;
367 /* Whirrr, whirrr, whirrrrrrrrr... */
368 if (secondary_cpu_start(cpuid, idle))
369 return -1;
371 /* Notify the secondary CPU it can run calibrate_delay. */
372 mb();
373 smp_secondary_alive = 0;
375 /* We've been acked by the console; wait one second for
376 the task to start up for real. */
377 timeout = jiffies + 1*HZ;
378 while (time_before(jiffies, timeout)) {
379 if (smp_secondary_alive == 1)
380 goto alive;
381 udelay(10);
382 barrier();
385 /* We failed to boot the CPU. */
387 printk(KERN_ERR "SMP: Processor %d is stuck.\n", cpuid);
388 return -1;
390 alive:
391 /* Another "Red Snapper". */
392 return 0;
396 * Called from setup_arch. Detect an SMP system and which processors
397 * are present.
399 void __init
400 setup_smp(void)
402 struct percpu_struct *cpubase, *cpu;
403 unsigned long i;
405 if (boot_cpuid != 0) {
406 printk(KERN_WARNING "SMP: Booting off cpu %d instead of 0?\n",
407 boot_cpuid);
410 if (hwrpb->nr_processors > 1) {
411 int boot_cpu_palrev;
413 DBGS(("setup_smp: nr_processors %ld\n",
414 hwrpb->nr_processors));
416 cpubase = (struct percpu_struct *)
417 ((char*)hwrpb + hwrpb->processor_offset);
418 boot_cpu_palrev = cpubase->pal_revision;
420 for (i = 0; i < hwrpb->nr_processors; i++) {
421 cpu = (struct percpu_struct *)
422 ((char *)cpubase + i*hwrpb->processor_size);
423 if ((cpu->flags & 0x1cc) == 0x1cc) {
424 smp_num_probed++;
425 set_cpu_possible(i, true);
426 set_cpu_present(i, true);
427 cpu->pal_revision = boot_cpu_palrev;
430 DBGS(("setup_smp: CPU %d: flags 0x%lx type 0x%lx\n",
431 i, cpu->flags, cpu->type));
432 DBGS(("setup_smp: CPU %d: PAL rev 0x%lx\n",
433 i, cpu->pal_revision));
435 } else {
436 smp_num_probed = 1;
439 printk(KERN_INFO "SMP: %d CPUs probed -- cpu_present_mask = %lx\n",
440 smp_num_probed, cpumask_bits(cpu_present_mask)[0]);
444 * Called by smp_init prepare the secondaries
446 void __init
447 smp_prepare_cpus(unsigned int max_cpus)
449 /* Take care of some initial bookkeeping. */
450 memset(ipi_data, 0, sizeof(ipi_data));
452 current_thread_info()->cpu = boot_cpuid;
454 smp_store_cpu_info(boot_cpuid);
455 smp_setup_percpu_timer(boot_cpuid);
457 /* Nothing to do on a UP box, or when told not to. */
458 if (smp_num_probed == 1 || max_cpus == 0) {
459 init_cpu_possible(cpumask_of(boot_cpuid));
460 init_cpu_present(cpumask_of(boot_cpuid));
461 printk(KERN_INFO "SMP mode deactivated.\n");
462 return;
465 printk(KERN_INFO "SMP starting up secondaries.\n");
467 smp_num_cpus = smp_num_probed;
470 void
471 smp_prepare_boot_cpu(void)
475 int __cpuinit
476 __cpu_up(unsigned int cpu, struct task_struct *tidle)
478 smp_boot_one_cpu(cpu, tidle);
480 return cpu_online(cpu) ? 0 : -ENOSYS;
483 void __init
484 smp_cpus_done(unsigned int max_cpus)
486 int cpu;
487 unsigned long bogosum = 0;
489 for(cpu = 0; cpu < NR_CPUS; cpu++)
490 if (cpu_online(cpu))
491 bogosum += cpu_data[cpu].loops_per_jiffy;
493 printk(KERN_INFO "SMP: Total of %d processors activated "
494 "(%lu.%02lu BogoMIPS).\n",
495 num_online_cpus(),
496 (bogosum + 2500) / (500000/HZ),
497 ((bogosum + 2500) / (5000/HZ)) % 100);
501 void
502 smp_percpu_timer_interrupt(struct pt_regs *regs)
504 struct pt_regs *old_regs;
505 int cpu = smp_processor_id();
506 unsigned long user = user_mode(regs);
507 struct cpuinfo_alpha *data = &cpu_data[cpu];
509 old_regs = set_irq_regs(regs);
511 /* Record kernel PC. */
512 profile_tick(CPU_PROFILING);
514 if (!--data->prof_counter) {
515 /* We need to make like a normal interrupt -- otherwise
516 timer interrupts ignore the global interrupt lock,
517 which would be a Bad Thing. */
518 irq_enter();
520 update_process_times(user);
522 data->prof_counter = data->prof_multiplier;
524 irq_exit();
526 set_irq_regs(old_regs);
530 setup_profiling_timer(unsigned int multiplier)
532 return -EINVAL;
536 static void
537 send_ipi_message(const struct cpumask *to_whom, enum ipi_message_type operation)
539 int i;
541 mb();
542 for_each_cpu(i, to_whom)
543 set_bit(operation, &ipi_data[i].bits);
545 mb();
546 for_each_cpu(i, to_whom)
547 wripir(i);
550 void
551 handle_ipi(struct pt_regs *regs)
553 int this_cpu = smp_processor_id();
554 unsigned long *pending_ipis = &ipi_data[this_cpu].bits;
555 unsigned long ops;
557 #if 0
558 DBGS(("handle_ipi: on CPU %d ops 0x%lx PC 0x%lx\n",
559 this_cpu, *pending_ipis, regs->pc));
560 #endif
562 mb(); /* Order interrupt and bit testing. */
563 while ((ops = xchg(pending_ipis, 0)) != 0) {
564 mb(); /* Order bit clearing and data access. */
565 do {
566 unsigned long which;
568 which = ops & -ops;
569 ops &= ~which;
570 which = __ffs(which);
572 switch (which) {
573 case IPI_RESCHEDULE:
574 scheduler_ipi();
575 break;
577 case IPI_CALL_FUNC:
578 generic_smp_call_function_interrupt();
579 break;
581 case IPI_CALL_FUNC_SINGLE:
582 generic_smp_call_function_single_interrupt();
583 break;
585 case IPI_CPU_STOP:
586 halt();
588 default:
589 printk(KERN_CRIT "Unknown IPI on CPU %d: %lu\n",
590 this_cpu, which);
591 break;
593 } while (ops);
595 mb(); /* Order data access and bit testing. */
598 cpu_data[this_cpu].ipi_count++;
600 if (hwrpb->txrdy)
601 recv_secondary_console_msg();
604 void
605 smp_send_reschedule(int cpu)
607 #ifdef DEBUG_IPI_MSG
608 if (cpu == hard_smp_processor_id())
609 printk(KERN_WARNING
610 "smp_send_reschedule: Sending IPI to self.\n");
611 #endif
612 send_ipi_message(cpumask_of(cpu), IPI_RESCHEDULE);
615 void
616 smp_send_stop(void)
618 cpumask_t to_whom;
619 cpumask_copy(&to_whom, cpu_possible_mask);
620 cpumask_clear_cpu(smp_processor_id(), &to_whom);
621 #ifdef DEBUG_IPI_MSG
622 if (hard_smp_processor_id() != boot_cpu_id)
623 printk(KERN_WARNING "smp_send_stop: Not on boot cpu.\n");
624 #endif
625 send_ipi_message(&to_whom, IPI_CPU_STOP);
628 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
630 send_ipi_message(mask, IPI_CALL_FUNC);
633 void arch_send_call_function_single_ipi(int cpu)
635 send_ipi_message(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE);
638 static void
639 ipi_imb(void *ignored)
641 imb();
644 void
645 smp_imb(void)
647 /* Must wait other processors to flush their icache before continue. */
648 if (on_each_cpu(ipi_imb, NULL, 1))
649 printk(KERN_CRIT "smp_imb: timed out\n");
651 EXPORT_SYMBOL(smp_imb);
653 static void
654 ipi_flush_tlb_all(void *ignored)
656 tbia();
659 void
660 flush_tlb_all(void)
662 /* Although we don't have any data to pass, we do want to
663 synchronize with the other processors. */
664 if (on_each_cpu(ipi_flush_tlb_all, NULL, 1)) {
665 printk(KERN_CRIT "flush_tlb_all: timed out\n");
669 #define asn_locked() (cpu_data[smp_processor_id()].asn_lock)
671 static void
672 ipi_flush_tlb_mm(void *x)
674 struct mm_struct *mm = (struct mm_struct *) x;
675 if (mm == current->active_mm && !asn_locked())
676 flush_tlb_current(mm);
677 else
678 flush_tlb_other(mm);
681 void
682 flush_tlb_mm(struct mm_struct *mm)
684 preempt_disable();
686 if (mm == current->active_mm) {
687 flush_tlb_current(mm);
688 if (atomic_read(&mm->mm_users) <= 1) {
689 int cpu, this_cpu = smp_processor_id();
690 for (cpu = 0; cpu < NR_CPUS; cpu++) {
691 if (!cpu_online(cpu) || cpu == this_cpu)
692 continue;
693 if (mm->context[cpu])
694 mm->context[cpu] = 0;
696 preempt_enable();
697 return;
701 if (smp_call_function(ipi_flush_tlb_mm, mm, 1)) {
702 printk(KERN_CRIT "flush_tlb_mm: timed out\n");
705 preempt_enable();
707 EXPORT_SYMBOL(flush_tlb_mm);
709 struct flush_tlb_page_struct {
710 struct vm_area_struct *vma;
711 struct mm_struct *mm;
712 unsigned long addr;
715 static void
716 ipi_flush_tlb_page(void *x)
718 struct flush_tlb_page_struct *data = (struct flush_tlb_page_struct *)x;
719 struct mm_struct * mm = data->mm;
721 if (mm == current->active_mm && !asn_locked())
722 flush_tlb_current_page(mm, data->vma, data->addr);
723 else
724 flush_tlb_other(mm);
727 void
728 flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)
730 struct flush_tlb_page_struct data;
731 struct mm_struct *mm = vma->vm_mm;
733 preempt_disable();
735 if (mm == current->active_mm) {
736 flush_tlb_current_page(mm, vma, addr);
737 if (atomic_read(&mm->mm_users) <= 1) {
738 int cpu, this_cpu = smp_processor_id();
739 for (cpu = 0; cpu < NR_CPUS; cpu++) {
740 if (!cpu_online(cpu) || cpu == this_cpu)
741 continue;
742 if (mm->context[cpu])
743 mm->context[cpu] = 0;
745 preempt_enable();
746 return;
750 data.vma = vma;
751 data.mm = mm;
752 data.addr = addr;
754 if (smp_call_function(ipi_flush_tlb_page, &data, 1)) {
755 printk(KERN_CRIT "flush_tlb_page: timed out\n");
758 preempt_enable();
760 EXPORT_SYMBOL(flush_tlb_page);
762 void
763 flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
765 /* On the Alpha we always flush the whole user tlb. */
766 flush_tlb_mm(vma->vm_mm);
768 EXPORT_SYMBOL(flush_tlb_range);
770 static void
771 ipi_flush_icache_page(void *x)
773 struct mm_struct *mm = (struct mm_struct *) x;
774 if (mm == current->active_mm && !asn_locked())
775 __load_new_mm_context(mm);
776 else
777 flush_tlb_other(mm);
780 void
781 flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
782 unsigned long addr, int len)
784 struct mm_struct *mm = vma->vm_mm;
786 if ((vma->vm_flags & VM_EXEC) == 0)
787 return;
789 preempt_disable();
791 if (mm == current->active_mm) {
792 __load_new_mm_context(mm);
793 if (atomic_read(&mm->mm_users) <= 1) {
794 int cpu, this_cpu = smp_processor_id();
795 for (cpu = 0; cpu < NR_CPUS; cpu++) {
796 if (!cpu_online(cpu) || cpu == this_cpu)
797 continue;
798 if (mm->context[cpu])
799 mm->context[cpu] = 0;
801 preempt_enable();
802 return;
806 if (smp_call_function(ipi_flush_icache_page, mm, 1)) {
807 printk(KERN_CRIT "flush_icache_page: timed out\n");
810 preempt_enable();