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>
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>
31 #include <asm/hwrpb.h>
32 #include <asm/ptrace.h>
33 #include <asm/atomic.h>
37 #include <asm/pgtable.h>
38 #include <asm/pgalloc.h>
39 #include <asm/mmu_context.h>
40 #include <asm/tlbflush.h>
48 #define DBGS(args) printk args
53 /* A collection of per-processor data. */
54 struct cpuinfo_alpha cpu_data[NR_CPUS];
55 EXPORT_SYMBOL(cpu_data);
57 /* A collection of single bit ipi messages. */
59 unsigned long bits ____cacheline_aligned;
60 } ipi_data[NR_CPUS] __cacheline_aligned;
62 enum ipi_message_type {
69 /* Set to a secondary's cpuid when it comes online. */
70 static int smp_secondary_alive __devinitdata = 0;
72 /* Which cpus ids came online. */
73 cpumask_t cpu_online_map;
75 EXPORT_SYMBOL(cpu_online_map);
77 int smp_num_probed; /* Internal processor count */
78 int smp_num_cpus = 1; /* Number that came online. */
79 EXPORT_SYMBOL(smp_num_cpus);
82 * Called by both boot and secondaries to move global data into
83 * per-processor storage.
85 static inline void __init
86 smp_store_cpu_info(int cpuid)
88 cpu_data[cpuid].loops_per_jiffy = loops_per_jiffy;
89 cpu_data[cpuid].last_asn = ASN_FIRST_VERSION;
90 cpu_data[cpuid].need_new_asn = 0;
91 cpu_data[cpuid].asn_lock = 0;
95 * Ideally sets up per-cpu profiling hooks. Doesn't do much now...
97 static inline void __init
98 smp_setup_percpu_timer(int cpuid)
100 cpu_data[cpuid].prof_counter = 1;
101 cpu_data[cpuid].prof_multiplier = 1;
105 wait_boot_cpu_to_stop(int cpuid)
107 unsigned long stop = jiffies + 10*HZ;
109 while (time_before(jiffies, stop)) {
110 if (!smp_secondary_alive)
115 printk("wait_boot_cpu_to_stop: FAILED on CPU %d, hanging now\n", cpuid);
121 * Where secondaries begin a life of C.
126 int cpuid = hard_smp_processor_id();
128 if (cpu_test_and_set(cpuid, cpu_online_map)) {
129 printk("??, cpu 0x%x already present??\n", cpuid);
133 /* Turn on machine checks. */
136 /* Set trap vectors. */
139 /* Set interrupt vector. */
142 /* Get our local ticker going. */
143 smp_setup_percpu_timer(cpuid);
145 /* Call platform-specific callin, if specified */
146 if (alpha_mv.smp_callin) alpha_mv.smp_callin();
148 /* All kernel threads share the same mm context. */
149 atomic_inc(&init_mm.mm_count);
150 current->active_mm = &init_mm;
152 /* Must have completely accurate bogos. */
155 /* Wait boot CPU to stop with irq enabled before running
157 wait_boot_cpu_to_stop(cpuid);
161 smp_store_cpu_info(cpuid);
162 /* Allow master to continue only after we written loops_per_jiffy. */
164 smp_secondary_alive = 1;
166 DBGS(("smp_callin: commencing CPU %d current %p active_mm %p\n",
167 cpuid, current, current->active_mm));
173 /* Wait until hwrpb->txrdy is clear for cpu. Return -1 on timeout. */
175 wait_for_txrdy (unsigned long cpumask)
177 unsigned long timeout;
179 if (!(hwrpb->txrdy & cpumask))
182 timeout = jiffies + 10*HZ;
183 while (time_before(jiffies, timeout)) {
184 if (!(hwrpb->txrdy & cpumask))
194 * Send a message to a secondary's console. "START" is one such
195 * interesting message. ;-)
198 send_secondary_console_msg(char *str, int cpuid)
200 struct percpu_struct *cpu;
201 register char *cp1, *cp2;
202 unsigned long cpumask;
205 cpu = (struct percpu_struct *)
207 + hwrpb->processor_offset
208 + cpuid * hwrpb->processor_size);
210 cpumask = (1UL << cpuid);
211 if (wait_for_txrdy(cpumask))
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 */
222 set_bit(cpuid, &hwrpb->rxrdy);
224 if (wait_for_txrdy(cpumask))
229 printk("Processor %x not ready\n", cpuid);
233 * A secondary console wants to send a message. Receive it.
236 recv_secondary_console_msg(void)
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)))
251 DBGS(("recv_secondary_console_msg: "
252 "TXRDY contains CPU %d.\n", i));
254 cpu = (struct percpu_struct *)
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 >>>");
267 cp1 = (char *) &cpu->ipc_buffer[11];
271 while ((cp2 = strchr(cp2, '\r')) != 0) {
278 DBGS((KERN_INFO "recv_secondary_console_msg: on %d "
279 "message is '%s'\n", mycpu, buf));
286 * Convince the console to have a secondary cpu begin execution.
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 *)
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;
308 hwpcb->ptbr = ipcb->ptbr;
311 hwpcb->unique = virt_to_phys(ipcb);
312 hwpcb->flags = ipcb->flags;
313 hwpcb->res1 = hwpcb->res2 = 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));
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 */
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)) {
348 printk(KERN_ERR "SMP: Processor %d failed to start.\n", cpuid);
352 DBGS(("secondary_cpu_start: SUCCESS for CPU %d!!!\n", cpuid));
357 * Bring one cpu online.
360 smp_boot_one_cpu(int cpuid)
362 struct task_struct *idle;
363 unsigned long timeout;
365 /* Cook up an idler for this guy. Note that the address we
366 give to kernel_thread is irrelevant -- it's going to start
367 where HWRPB.CPU_restart says to start. But this gets all
368 the other task-y sort of data structures set up like we
369 wish. We can't use kernel_thread since we must avoid
370 rescheduling the child. */
371 idle = fork_idle(cpuid);
373 panic("failed fork for CPU %d", cpuid);
375 DBGS(("smp_boot_one_cpu: CPU %d state 0x%lx flags 0x%lx\n",
376 cpuid, idle->state, idle->flags));
378 /* Signal the secondary to wait a moment. */
379 smp_secondary_alive = -1;
381 /* Whirrr, whirrr, whirrrrrrrrr... */
382 if (secondary_cpu_start(cpuid, idle))
385 /* Notify the secondary CPU it can run calibrate_delay. */
387 smp_secondary_alive = 0;
389 /* We've been acked by the console; wait one second for
390 the task to start up for real. */
391 timeout = jiffies + 1*HZ;
392 while (time_before(jiffies, timeout)) {
393 if (smp_secondary_alive == 1)
399 /* We failed to boot the CPU. */
401 printk(KERN_ERR "SMP: Processor %d is stuck.\n", cpuid);
405 /* Another "Red Snapper". */
410 * Called from setup_arch. Detect an SMP system and which processors
416 struct percpu_struct *cpubase, *cpu;
419 if (boot_cpuid != 0) {
420 printk(KERN_WARNING "SMP: Booting off cpu %d instead of 0?\n",
424 if (hwrpb->nr_processors > 1) {
427 DBGS(("setup_smp: nr_processors %ld\n",
428 hwrpb->nr_processors));
430 cpubase = (struct percpu_struct *)
431 ((char*)hwrpb + hwrpb->processor_offset);
432 boot_cpu_palrev = cpubase->pal_revision;
434 for (i = 0; i < hwrpb->nr_processors; i++) {
435 cpu = (struct percpu_struct *)
436 ((char *)cpubase + i*hwrpb->processor_size);
437 if ((cpu->flags & 0x1cc) == 0x1cc) {
439 cpu_set(i, cpu_present_map);
440 cpu->pal_revision = boot_cpu_palrev;
443 DBGS(("setup_smp: CPU %d: flags 0x%lx type 0x%lx\n",
444 i, cpu->flags, cpu->type));
445 DBGS(("setup_smp: CPU %d: PAL rev 0x%lx\n",
446 i, cpu->pal_revision));
452 printk(KERN_INFO "SMP: %d CPUs probed -- cpu_present_map = %lx\n",
453 smp_num_probed, cpu_present_map.bits[0]);
457 * Called by smp_init prepare the secondaries
460 smp_prepare_cpus(unsigned int max_cpus)
462 /* Take care of some initial bookkeeping. */
463 memset(ipi_data, 0, sizeof(ipi_data));
465 current_thread_info()->cpu = boot_cpuid;
467 smp_store_cpu_info(boot_cpuid);
468 smp_setup_percpu_timer(boot_cpuid);
470 /* Nothing to do on a UP box, or when told not to. */
471 if (smp_num_probed == 1 || max_cpus == 0) {
472 cpu_present_map = cpumask_of_cpu(boot_cpuid);
473 printk(KERN_INFO "SMP mode deactivated.\n");
477 printk(KERN_INFO "SMP starting up secondaries.\n");
479 smp_num_cpus = smp_num_probed;
483 smp_prepare_boot_cpu(void)
488 __cpu_up(unsigned int cpu)
490 smp_boot_one_cpu(cpu);
492 return cpu_online(cpu) ? 0 : -ENOSYS;
496 smp_cpus_done(unsigned int max_cpus)
499 unsigned long bogosum = 0;
501 for(cpu = 0; cpu < NR_CPUS; cpu++)
503 bogosum += cpu_data[cpu].loops_per_jiffy;
505 printk(KERN_INFO "SMP: Total of %d processors activated "
506 "(%lu.%02lu BogoMIPS).\n",
508 (bogosum + 2500) / (500000/HZ),
509 ((bogosum + 2500) / (5000/HZ)) % 100);
514 smp_percpu_timer_interrupt(struct pt_regs *regs)
516 struct pt_regs *old_regs;
517 int cpu = smp_processor_id();
518 unsigned long user = user_mode(regs);
519 struct cpuinfo_alpha *data = &cpu_data[cpu];
521 old_regs = set_irq_regs(regs);
523 /* Record kernel PC. */
524 profile_tick(CPU_PROFILING);
526 if (!--data->prof_counter) {
527 /* We need to make like a normal interrupt -- otherwise
528 timer interrupts ignore the global interrupt lock,
529 which would be a Bad Thing. */
532 update_process_times(user);
534 data->prof_counter = data->prof_multiplier;
538 set_irq_regs(old_regs);
542 setup_profiling_timer(unsigned int multiplier)
549 send_ipi_message(cpumask_t to_whom, enum ipi_message_type operation)
554 for_each_cpu_mask(i, to_whom)
555 set_bit(operation, &ipi_data[i].bits);
558 for_each_cpu_mask(i, to_whom)
563 handle_ipi(struct pt_regs *regs)
565 int this_cpu = smp_processor_id();
566 unsigned long *pending_ipis = &ipi_data[this_cpu].bits;
570 DBGS(("handle_ipi: on CPU %d ops 0x%lx PC 0x%lx\n",
571 this_cpu, *pending_ipis, regs->pc));
574 mb(); /* Order interrupt and bit testing. */
575 while ((ops = xchg(pending_ipis, 0)) != 0) {
576 mb(); /* Order bit clearing and data access. */
582 which = __ffs(which);
586 /* Reschedule callback. Everything to be done
587 is done by the interrupt return path. */
591 generic_smp_call_function_interrupt();
594 case IPI_CALL_FUNC_SINGLE:
595 generic_smp_call_function_single_interrupt();
602 printk(KERN_CRIT "Unknown IPI on CPU %d: %lu\n",
608 mb(); /* Order data access and bit testing. */
611 cpu_data[this_cpu].ipi_count++;
614 recv_secondary_console_msg();
618 smp_send_reschedule(int cpu)
621 if (cpu == hard_smp_processor_id())
623 "smp_send_reschedule: Sending IPI to self.\n");
625 send_ipi_message(cpumask_of_cpu(cpu), IPI_RESCHEDULE);
631 cpumask_t to_whom = cpu_possible_map;
632 cpu_clear(smp_processor_id(), to_whom);
634 if (hard_smp_processor_id() != boot_cpu_id)
635 printk(KERN_WARNING "smp_send_stop: Not on boot cpu.\n");
637 send_ipi_message(to_whom, IPI_CPU_STOP);
640 void arch_send_call_function_ipi(cpumask_t mask)
642 send_ipi_message(mask, IPI_CALL_FUNC);
645 void arch_send_call_function_single_ipi(int cpu)
647 send_ipi_message(cpumask_of_cpu(cpu), IPI_CALL_FUNC_SINGLE);
651 ipi_imb(void *ignored)
659 /* Must wait other processors to flush their icache before continue. */
660 if (on_each_cpu(ipi_imb, NULL, 1))
661 printk(KERN_CRIT "smp_imb: timed out\n");
663 EXPORT_SYMBOL(smp_imb);
666 ipi_flush_tlb_all(void *ignored)
674 /* Although we don't have any data to pass, we do want to
675 synchronize with the other processors. */
676 if (on_each_cpu(ipi_flush_tlb_all, NULL, 1)) {
677 printk(KERN_CRIT "flush_tlb_all: timed out\n");
681 #define asn_locked() (cpu_data[smp_processor_id()].asn_lock)
684 ipi_flush_tlb_mm(void *x)
686 struct mm_struct *mm = (struct mm_struct *) x;
687 if (mm == current->active_mm && !asn_locked())
688 flush_tlb_current(mm);
694 flush_tlb_mm(struct mm_struct *mm)
698 if (mm == current->active_mm) {
699 flush_tlb_current(mm);
700 if (atomic_read(&mm->mm_users) <= 1) {
701 int cpu, this_cpu = smp_processor_id();
702 for (cpu = 0; cpu < NR_CPUS; cpu++) {
703 if (!cpu_online(cpu) || cpu == this_cpu)
705 if (mm->context[cpu])
706 mm->context[cpu] = 0;
713 if (smp_call_function(ipi_flush_tlb_mm, mm, 1)) {
714 printk(KERN_CRIT "flush_tlb_mm: timed out\n");
719 EXPORT_SYMBOL(flush_tlb_mm);
721 struct flush_tlb_page_struct {
722 struct vm_area_struct *vma;
723 struct mm_struct *mm;
728 ipi_flush_tlb_page(void *x)
730 struct flush_tlb_page_struct *data = (struct flush_tlb_page_struct *)x;
731 struct mm_struct * mm = data->mm;
733 if (mm == current->active_mm && !asn_locked())
734 flush_tlb_current_page(mm, data->vma, data->addr);
740 flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)
742 struct flush_tlb_page_struct data;
743 struct mm_struct *mm = vma->vm_mm;
747 if (mm == current->active_mm) {
748 flush_tlb_current_page(mm, vma, addr);
749 if (atomic_read(&mm->mm_users) <= 1) {
750 int cpu, this_cpu = smp_processor_id();
751 for (cpu = 0; cpu < NR_CPUS; cpu++) {
752 if (!cpu_online(cpu) || cpu == this_cpu)
754 if (mm->context[cpu])
755 mm->context[cpu] = 0;
766 if (smp_call_function(ipi_flush_tlb_page, &data, 1)) {
767 printk(KERN_CRIT "flush_tlb_page: timed out\n");
772 EXPORT_SYMBOL(flush_tlb_page);
775 flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
777 /* On the Alpha we always flush the whole user tlb. */
778 flush_tlb_mm(vma->vm_mm);
780 EXPORT_SYMBOL(flush_tlb_range);
783 ipi_flush_icache_page(void *x)
785 struct mm_struct *mm = (struct mm_struct *) x;
786 if (mm == current->active_mm && !asn_locked())
787 __load_new_mm_context(mm);
793 flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
794 unsigned long addr, int len)
796 struct mm_struct *mm = vma->vm_mm;
798 if ((vma->vm_flags & VM_EXEC) == 0)
803 if (mm == current->active_mm) {
804 __load_new_mm_context(mm);
805 if (atomic_read(&mm->mm_users) <= 1) {
806 int cpu, this_cpu = smp_processor_id();
807 for (cpu = 0; cpu < NR_CPUS; cpu++) {
808 if (!cpu_online(cpu) || cpu == this_cpu)
810 if (mm->context[cpu])
811 mm->context[cpu] = 0;
818 if (smp_call_function(ipi_flush_icache_page, mm, 1)) {
819 printk(KERN_CRIT "flush_icache_page: timed out\n");