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 /* inform the notifiers about the new cpu */
153 notify_cpu_starting(cpuid);
155 /* Must have completely accurate bogos. */
158 /* Wait boot CPU to stop with irq enabled before running
160 wait_boot_cpu_to_stop(cpuid);
164 smp_store_cpu_info(cpuid);
165 /* Allow master to continue only after we written loops_per_jiffy. */
167 smp_secondary_alive = 1;
169 DBGS(("smp_callin: commencing CPU %d current %p active_mm %p\n",
170 cpuid, current, current->active_mm));
176 /* Wait until hwrpb->txrdy is clear for cpu. Return -1 on timeout. */
178 wait_for_txrdy (unsigned long cpumask)
180 unsigned long timeout;
182 if (!(hwrpb->txrdy & cpumask))
185 timeout = jiffies + 10*HZ;
186 while (time_before(jiffies, timeout)) {
187 if (!(hwrpb->txrdy & cpumask))
197 * Send a message to a secondary's console. "START" is one such
198 * interesting message. ;-)
201 send_secondary_console_msg(char *str, int cpuid)
203 struct percpu_struct *cpu;
204 register char *cp1, *cp2;
205 unsigned long cpumask;
208 cpu = (struct percpu_struct *)
210 + hwrpb->processor_offset
211 + cpuid * hwrpb->processor_size);
213 cpumask = (1UL << cpuid);
214 if (wait_for_txrdy(cpumask))
219 *(unsigned int *)&cpu->ipc_buffer[0] = len;
220 cp1 = (char *) &cpu->ipc_buffer[1];
221 memcpy(cp1, cp2, len);
223 /* atomic test and set */
225 set_bit(cpuid, &hwrpb->rxrdy);
227 if (wait_for_txrdy(cpumask))
232 printk("Processor %x not ready\n", cpuid);
236 * A secondary console wants to send a message. Receive it.
239 recv_secondary_console_msg(void)
242 unsigned long txrdy = hwrpb->txrdy;
243 char *cp1, *cp2, buf[80];
244 struct percpu_struct *cpu;
246 DBGS(("recv_secondary_console_msg: TXRDY 0x%lx.\n", txrdy));
248 mycpu = hard_smp_processor_id();
250 for (i = 0; i < NR_CPUS; i++) {
251 if (!(txrdy & (1UL << i)))
254 DBGS(("recv_secondary_console_msg: "
255 "TXRDY contains CPU %d.\n", i));
257 cpu = (struct percpu_struct *)
259 + hwrpb->processor_offset
260 + i * hwrpb->processor_size);
262 DBGS(("recv_secondary_console_msg: on %d from %d"
263 " HALT_REASON 0x%lx FLAGS 0x%lx\n",
264 mycpu, i, cpu->halt_reason, cpu->flags));
266 cnt = cpu->ipc_buffer[0] >> 32;
267 if (cnt <= 0 || cnt >= 80)
268 strcpy(buf, "<<< BOGUS MSG >>>");
270 cp1 = (char *) &cpu->ipc_buffer[11];
274 while ((cp2 = strchr(cp2, '\r')) != 0) {
281 DBGS((KERN_INFO "recv_secondary_console_msg: on %d "
282 "message is '%s'\n", mycpu, buf));
289 * Convince the console to have a secondary cpu begin execution.
292 secondary_cpu_start(int cpuid, struct task_struct *idle)
294 struct percpu_struct *cpu;
295 struct pcb_struct *hwpcb, *ipcb;
296 unsigned long timeout;
298 cpu = (struct percpu_struct *)
300 + hwrpb->processor_offset
301 + cpuid * hwrpb->processor_size);
302 hwpcb = (struct pcb_struct *) cpu->hwpcb;
303 ipcb = &task_thread_info(idle)->pcb;
305 /* Initialize the CPU's HWPCB to something just good enough for
306 us to get started. Immediately after starting, we'll swpctx
307 to the target idle task's pcb. Reuse the stack in the mean
308 time. Precalculate the target PCBB. */
309 hwpcb->ksp = (unsigned long)ipcb + sizeof(union thread_union) - 16;
311 hwpcb->ptbr = ipcb->ptbr;
314 hwpcb->unique = virt_to_phys(ipcb);
315 hwpcb->flags = ipcb->flags;
316 hwpcb->res1 = hwpcb->res2 = 0;
319 DBGS(("KSP 0x%lx PTBR 0x%lx VPTBR 0x%lx UNIQUE 0x%lx\n",
320 hwpcb->ksp, hwpcb->ptbr, hwrpb->vptb, hwpcb->unique));
322 DBGS(("Starting secondary cpu %d: state 0x%lx pal_flags 0x%lx\n",
323 cpuid, idle->state, ipcb->flags));
325 /* Setup HWRPB fields that SRM uses to activate secondary CPU */
326 hwrpb->CPU_restart = __smp_callin;
327 hwrpb->CPU_restart_data = (unsigned long) __smp_callin;
329 /* Recalculate and update the HWRPB checksum */
330 hwrpb_update_checksum(hwrpb);
333 * Send a "start" command to the specified processor.
336 /* SRM III 3.4.1.3 */
337 cpu->flags |= 0x22; /* turn on Context Valid and Restart Capable */
338 cpu->flags &= ~1; /* turn off Bootstrap In Progress */
341 send_secondary_console_msg("START\r\n", cpuid);
343 /* Wait 10 seconds for an ACK from the console. */
344 timeout = jiffies + 10*HZ;
345 while (time_before(jiffies, timeout)) {
351 printk(KERN_ERR "SMP: Processor %d failed to start.\n", cpuid);
355 DBGS(("secondary_cpu_start: SUCCESS for CPU %d!!!\n", cpuid));
360 * Bring one cpu online.
363 smp_boot_one_cpu(int cpuid)
365 struct task_struct *idle;
366 unsigned long timeout;
368 /* Cook up an idler for this guy. Note that the address we
369 give to kernel_thread is irrelevant -- it's going to start
370 where HWRPB.CPU_restart says to start. But this gets all
371 the other task-y sort of data structures set up like we
372 wish. We can't use kernel_thread since we must avoid
373 rescheduling the child. */
374 idle = fork_idle(cpuid);
376 panic("failed fork for CPU %d", cpuid);
378 DBGS(("smp_boot_one_cpu: CPU %d state 0x%lx flags 0x%lx\n",
379 cpuid, idle->state, idle->flags));
381 /* Signal the secondary to wait a moment. */
382 smp_secondary_alive = -1;
384 /* Whirrr, whirrr, whirrrrrrrrr... */
385 if (secondary_cpu_start(cpuid, idle))
388 /* Notify the secondary CPU it can run calibrate_delay. */
390 smp_secondary_alive = 0;
392 /* We've been acked by the console; wait one second for
393 the task to start up for real. */
394 timeout = jiffies + 1*HZ;
395 while (time_before(jiffies, timeout)) {
396 if (smp_secondary_alive == 1)
402 /* We failed to boot the CPU. */
404 printk(KERN_ERR "SMP: Processor %d is stuck.\n", cpuid);
408 /* Another "Red Snapper". */
413 * Called from setup_arch. Detect an SMP system and which processors
419 struct percpu_struct *cpubase, *cpu;
422 if (boot_cpuid != 0) {
423 printk(KERN_WARNING "SMP: Booting off cpu %d instead of 0?\n",
427 if (hwrpb->nr_processors > 1) {
430 DBGS(("setup_smp: nr_processors %ld\n",
431 hwrpb->nr_processors));
433 cpubase = (struct percpu_struct *)
434 ((char*)hwrpb + hwrpb->processor_offset);
435 boot_cpu_palrev = cpubase->pal_revision;
437 for (i = 0; i < hwrpb->nr_processors; i++) {
438 cpu = (struct percpu_struct *)
439 ((char *)cpubase + i*hwrpb->processor_size);
440 if ((cpu->flags & 0x1cc) == 0x1cc) {
442 cpu_set(i, cpu_present_map);
443 cpu->pal_revision = boot_cpu_palrev;
446 DBGS(("setup_smp: CPU %d: flags 0x%lx type 0x%lx\n",
447 i, cpu->flags, cpu->type));
448 DBGS(("setup_smp: CPU %d: PAL rev 0x%lx\n",
449 i, cpu->pal_revision));
455 printk(KERN_INFO "SMP: %d CPUs probed -- cpu_present_map = %lx\n",
456 smp_num_probed, cpu_present_map.bits[0]);
460 * Called by smp_init prepare the secondaries
463 smp_prepare_cpus(unsigned int max_cpus)
465 /* Take care of some initial bookkeeping. */
466 memset(ipi_data, 0, sizeof(ipi_data));
468 current_thread_info()->cpu = boot_cpuid;
470 smp_store_cpu_info(boot_cpuid);
471 smp_setup_percpu_timer(boot_cpuid);
473 /* Nothing to do on a UP box, or when told not to. */
474 if (smp_num_probed == 1 || max_cpus == 0) {
475 cpu_present_map = cpumask_of_cpu(boot_cpuid);
476 printk(KERN_INFO "SMP mode deactivated.\n");
480 printk(KERN_INFO "SMP starting up secondaries.\n");
482 smp_num_cpus = smp_num_probed;
486 smp_prepare_boot_cpu(void)
491 __cpu_up(unsigned int cpu)
493 smp_boot_one_cpu(cpu);
495 return cpu_online(cpu) ? 0 : -ENOSYS;
499 smp_cpus_done(unsigned int max_cpus)
502 unsigned long bogosum = 0;
504 for(cpu = 0; cpu < NR_CPUS; cpu++)
506 bogosum += cpu_data[cpu].loops_per_jiffy;
508 printk(KERN_INFO "SMP: Total of %d processors activated "
509 "(%lu.%02lu BogoMIPS).\n",
511 (bogosum + 2500) / (500000/HZ),
512 ((bogosum + 2500) / (5000/HZ)) % 100);
517 smp_percpu_timer_interrupt(struct pt_regs *regs)
519 struct pt_regs *old_regs;
520 int cpu = smp_processor_id();
521 unsigned long user = user_mode(regs);
522 struct cpuinfo_alpha *data = &cpu_data[cpu];
524 old_regs = set_irq_regs(regs);
526 /* Record kernel PC. */
527 profile_tick(CPU_PROFILING);
529 if (!--data->prof_counter) {
530 /* We need to make like a normal interrupt -- otherwise
531 timer interrupts ignore the global interrupt lock,
532 which would be a Bad Thing. */
535 update_process_times(user);
537 data->prof_counter = data->prof_multiplier;
541 set_irq_regs(old_regs);
545 setup_profiling_timer(unsigned int multiplier)
552 send_ipi_message(cpumask_t to_whom, enum ipi_message_type operation)
557 for_each_cpu_mask(i, to_whom)
558 set_bit(operation, &ipi_data[i].bits);
561 for_each_cpu_mask(i, to_whom)
566 handle_ipi(struct pt_regs *regs)
568 int this_cpu = smp_processor_id();
569 unsigned long *pending_ipis = &ipi_data[this_cpu].bits;
573 DBGS(("handle_ipi: on CPU %d ops 0x%lx PC 0x%lx\n",
574 this_cpu, *pending_ipis, regs->pc));
577 mb(); /* Order interrupt and bit testing. */
578 while ((ops = xchg(pending_ipis, 0)) != 0) {
579 mb(); /* Order bit clearing and data access. */
585 which = __ffs(which);
589 /* Reschedule callback. Everything to be done
590 is done by the interrupt return path. */
594 generic_smp_call_function_interrupt();
597 case IPI_CALL_FUNC_SINGLE:
598 generic_smp_call_function_single_interrupt();
605 printk(KERN_CRIT "Unknown IPI on CPU %d: %lu\n",
611 mb(); /* Order data access and bit testing. */
614 cpu_data[this_cpu].ipi_count++;
617 recv_secondary_console_msg();
621 smp_send_reschedule(int cpu)
624 if (cpu == hard_smp_processor_id())
626 "smp_send_reschedule: Sending IPI to self.\n");
628 send_ipi_message(cpumask_of_cpu(cpu), IPI_RESCHEDULE);
634 cpumask_t to_whom = cpu_possible_map;
635 cpu_clear(smp_processor_id(), to_whom);
637 if (hard_smp_processor_id() != boot_cpu_id)
638 printk(KERN_WARNING "smp_send_stop: Not on boot cpu.\n");
640 send_ipi_message(to_whom, IPI_CPU_STOP);
643 void arch_send_call_function_ipi(cpumask_t mask)
645 send_ipi_message(mask, IPI_CALL_FUNC);
648 void arch_send_call_function_single_ipi(int cpu)
650 send_ipi_message(cpumask_of_cpu(cpu), IPI_CALL_FUNC_SINGLE);
654 ipi_imb(void *ignored)
662 /* Must wait other processors to flush their icache before continue. */
663 if (on_each_cpu(ipi_imb, NULL, 1))
664 printk(KERN_CRIT "smp_imb: timed out\n");
666 EXPORT_SYMBOL(smp_imb);
669 ipi_flush_tlb_all(void *ignored)
677 /* Although we don't have any data to pass, we do want to
678 synchronize with the other processors. */
679 if (on_each_cpu(ipi_flush_tlb_all, NULL, 1)) {
680 printk(KERN_CRIT "flush_tlb_all: timed out\n");
684 #define asn_locked() (cpu_data[smp_processor_id()].asn_lock)
687 ipi_flush_tlb_mm(void *x)
689 struct mm_struct *mm = (struct mm_struct *) x;
690 if (mm == current->active_mm && !asn_locked())
691 flush_tlb_current(mm);
697 flush_tlb_mm(struct mm_struct *mm)
701 if (mm == current->active_mm) {
702 flush_tlb_current(mm);
703 if (atomic_read(&mm->mm_users) <= 1) {
704 int cpu, this_cpu = smp_processor_id();
705 for (cpu = 0; cpu < NR_CPUS; cpu++) {
706 if (!cpu_online(cpu) || cpu == this_cpu)
708 if (mm->context[cpu])
709 mm->context[cpu] = 0;
716 if (smp_call_function(ipi_flush_tlb_mm, mm, 1)) {
717 printk(KERN_CRIT "flush_tlb_mm: timed out\n");
722 EXPORT_SYMBOL(flush_tlb_mm);
724 struct flush_tlb_page_struct {
725 struct vm_area_struct *vma;
726 struct mm_struct *mm;
731 ipi_flush_tlb_page(void *x)
733 struct flush_tlb_page_struct *data = (struct flush_tlb_page_struct *)x;
734 struct mm_struct * mm = data->mm;
736 if (mm == current->active_mm && !asn_locked())
737 flush_tlb_current_page(mm, data->vma, data->addr);
743 flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)
745 struct flush_tlb_page_struct data;
746 struct mm_struct *mm = vma->vm_mm;
750 if (mm == current->active_mm) {
751 flush_tlb_current_page(mm, vma, addr);
752 if (atomic_read(&mm->mm_users) <= 1) {
753 int cpu, this_cpu = smp_processor_id();
754 for (cpu = 0; cpu < NR_CPUS; cpu++) {
755 if (!cpu_online(cpu) || cpu == this_cpu)
757 if (mm->context[cpu])
758 mm->context[cpu] = 0;
769 if (smp_call_function(ipi_flush_tlb_page, &data, 1)) {
770 printk(KERN_CRIT "flush_tlb_page: timed out\n");
775 EXPORT_SYMBOL(flush_tlb_page);
778 flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
780 /* On the Alpha we always flush the whole user tlb. */
781 flush_tlb_mm(vma->vm_mm);
783 EXPORT_SYMBOL(flush_tlb_range);
786 ipi_flush_icache_page(void *x)
788 struct mm_struct *mm = (struct mm_struct *) x;
789 if (mm == current->active_mm && !asn_locked())
790 __load_new_mm_context(mm);
796 flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
797 unsigned long addr, int len)
799 struct mm_struct *mm = vma->vm_mm;
801 if ((vma->vm_flags & VM_EXEC) == 0)
806 if (mm == current->active_mm) {
807 __load_new_mm_context(mm);
808 if (atomic_read(&mm->mm_users) <= 1) {
809 int cpu, this_cpu = smp_processor_id();
810 for (cpu = 0; cpu < NR_CPUS; cpu++) {
811 if (!cpu_online(cpu) || cpu == this_cpu)
813 if (mm->context[cpu])
814 mm->context[cpu] = 0;
821 if (smp_call_function(ipi_flush_icache_page, mm, 1)) {
822 printk(KERN_CRIT "flush_icache_page: timed out\n");