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>
30 #include <linux/cpu.h>
32 #include <asm/hwrpb.h>
33 #include <asm/ptrace.h>
34 #include <asm/atomic.h>
38 #include <asm/pgtable.h>
39 #include <asm/pgalloc.h>
40 #include <asm/mmu_context.h>
41 #include <asm/tlbflush.h>
49 #define DBGS(args) printk args
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. */
60 unsigned long bits ____cacheline_aligned;
61 } ipi_data[NR_CPUS] __cacheline_aligned;
63 enum ipi_message_type {
70 /* Set to a secondary's cpuid when it comes online. */
71 static int smp_secondary_alive __devinitdata = 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;
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)
111 printk("wait_boot_cpu_to_stop: FAILED on CPU %d, hanging now\n", cpuid);
117 * Where secondaries begin a life of C.
122 int cpuid = hard_smp_processor_id();
124 if (cpu_online(cpuid)) {
125 printk("??, cpu 0x%x already present??\n", cpuid);
128 set_cpu_online(cpuid, true);
130 /* Turn on machine checks. */
133 /* Set trap vectors. */
136 /* Set interrupt vector. */
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. */
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. ;-)
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;
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 set_cpu_possible(i, true);
440 set_cpu_present(i, true);
441 cpu->pal_revision = boot_cpu_palrev;
444 DBGS(("setup_smp: CPU %d: flags 0x%lx type 0x%lx\n",
445 i, cpu->flags, cpu->type));
446 DBGS(("setup_smp: CPU %d: PAL rev 0x%lx\n",
447 i, cpu->pal_revision));
453 printk(KERN_INFO "SMP: %d CPUs probed -- cpu_present_map = %lx\n",
454 smp_num_probed, cpu_present_map.bits[0]);
458 * Called by smp_init prepare the secondaries
461 smp_prepare_cpus(unsigned int max_cpus)
463 /* Take care of some initial bookkeeping. */
464 memset(ipi_data, 0, sizeof(ipi_data));
466 current_thread_info()->cpu = boot_cpuid;
468 smp_store_cpu_info(boot_cpuid);
469 smp_setup_percpu_timer(boot_cpuid);
471 /* Nothing to do on a UP box, or when told not to. */
472 if (smp_num_probed == 1 || max_cpus == 0) {
473 init_cpu_possible(cpumask_of(boot_cpuid));
474 init_cpu_present(cpumask_of(boot_cpuid));
475 printk(KERN_INFO "SMP mode deactivated.\n");
479 printk(KERN_INFO "SMP starting up secondaries.\n");
481 smp_num_cpus = smp_num_probed;
485 smp_prepare_boot_cpu(void)
490 __cpu_up(unsigned int cpu)
492 smp_boot_one_cpu(cpu);
494 return cpu_online(cpu) ? 0 : -ENOSYS;
498 smp_cpus_done(unsigned int max_cpus)
501 unsigned long bogosum = 0;
503 for(cpu = 0; cpu < NR_CPUS; cpu++)
505 bogosum += cpu_data[cpu].loops_per_jiffy;
507 printk(KERN_INFO "SMP: Total of %d processors activated "
508 "(%lu.%02lu BogoMIPS).\n",
510 (bogosum + 2500) / (500000/HZ),
511 ((bogosum + 2500) / (5000/HZ)) % 100);
516 smp_percpu_timer_interrupt(struct pt_regs *regs)
518 struct pt_regs *old_regs;
519 int cpu = smp_processor_id();
520 unsigned long user = user_mode(regs);
521 struct cpuinfo_alpha *data = &cpu_data[cpu];
523 old_regs = set_irq_regs(regs);
525 /* Record kernel PC. */
526 profile_tick(CPU_PROFILING);
528 if (!--data->prof_counter) {
529 /* We need to make like a normal interrupt -- otherwise
530 timer interrupts ignore the global interrupt lock,
531 which would be a Bad Thing. */
534 update_process_times(user);
536 data->prof_counter = data->prof_multiplier;
540 set_irq_regs(old_regs);
544 setup_profiling_timer(unsigned int multiplier)
551 send_ipi_message(cpumask_t to_whom, enum ipi_message_type operation)
556 for_each_cpu_mask(i, to_whom)
557 set_bit(operation, &ipi_data[i].bits);
560 for_each_cpu_mask(i, to_whom)
565 handle_ipi(struct pt_regs *regs)
567 int this_cpu = smp_processor_id();
568 unsigned long *pending_ipis = &ipi_data[this_cpu].bits;
572 DBGS(("handle_ipi: on CPU %d ops 0x%lx PC 0x%lx\n",
573 this_cpu, *pending_ipis, regs->pc));
576 mb(); /* Order interrupt and bit testing. */
577 while ((ops = xchg(pending_ipis, 0)) != 0) {
578 mb(); /* Order bit clearing and data access. */
584 which = __ffs(which);
588 /* Reschedule callback. Everything to be done
589 is done by the interrupt return path. */
593 generic_smp_call_function_interrupt();
596 case IPI_CALL_FUNC_SINGLE:
597 generic_smp_call_function_single_interrupt();
604 printk(KERN_CRIT "Unknown IPI on CPU %d: %lu\n",
610 mb(); /* Order data access and bit testing. */
613 cpu_data[this_cpu].ipi_count++;
616 recv_secondary_console_msg();
620 smp_send_reschedule(int cpu)
623 if (cpu == hard_smp_processor_id())
625 "smp_send_reschedule: Sending IPI to self.\n");
627 send_ipi_message(cpumask_of_cpu(cpu), IPI_RESCHEDULE);
633 cpumask_t to_whom = cpu_possible_map;
634 cpu_clear(smp_processor_id(), to_whom);
636 if (hard_smp_processor_id() != boot_cpu_id)
637 printk(KERN_WARNING "smp_send_stop: Not on boot cpu.\n");
639 send_ipi_message(to_whom, IPI_CPU_STOP);
642 void arch_send_call_function_ipi(cpumask_t mask)
644 send_ipi_message(mask, IPI_CALL_FUNC);
647 void arch_send_call_function_single_ipi(int cpu)
649 send_ipi_message(cpumask_of_cpu(cpu), IPI_CALL_FUNC_SINGLE);
653 ipi_imb(void *ignored)
661 /* Must wait other processors to flush their icache before continue. */
662 if (on_each_cpu(ipi_imb, NULL, 1))
663 printk(KERN_CRIT "smp_imb: timed out\n");
665 EXPORT_SYMBOL(smp_imb);
668 ipi_flush_tlb_all(void *ignored)
676 /* Although we don't have any data to pass, we do want to
677 synchronize with the other processors. */
678 if (on_each_cpu(ipi_flush_tlb_all, NULL, 1)) {
679 printk(KERN_CRIT "flush_tlb_all: timed out\n");
683 #define asn_locked() (cpu_data[smp_processor_id()].asn_lock)
686 ipi_flush_tlb_mm(void *x)
688 struct mm_struct *mm = (struct mm_struct *) x;
689 if (mm == current->active_mm && !asn_locked())
690 flush_tlb_current(mm);
696 flush_tlb_mm(struct mm_struct *mm)
700 if (mm == current->active_mm) {
701 flush_tlb_current(mm);
702 if (atomic_read(&mm->mm_users) <= 1) {
703 int cpu, this_cpu = smp_processor_id();
704 for (cpu = 0; cpu < NR_CPUS; cpu++) {
705 if (!cpu_online(cpu) || cpu == this_cpu)
707 if (mm->context[cpu])
708 mm->context[cpu] = 0;
715 if (smp_call_function(ipi_flush_tlb_mm, mm, 1)) {
716 printk(KERN_CRIT "flush_tlb_mm: timed out\n");
721 EXPORT_SYMBOL(flush_tlb_mm);
723 struct flush_tlb_page_struct {
724 struct vm_area_struct *vma;
725 struct mm_struct *mm;
730 ipi_flush_tlb_page(void *x)
732 struct flush_tlb_page_struct *data = (struct flush_tlb_page_struct *)x;
733 struct mm_struct * mm = data->mm;
735 if (mm == current->active_mm && !asn_locked())
736 flush_tlb_current_page(mm, data->vma, data->addr);
742 flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)
744 struct flush_tlb_page_struct data;
745 struct mm_struct *mm = vma->vm_mm;
749 if (mm == current->active_mm) {
750 flush_tlb_current_page(mm, vma, addr);
751 if (atomic_read(&mm->mm_users) <= 1) {
752 int cpu, this_cpu = smp_processor_id();
753 for (cpu = 0; cpu < NR_CPUS; cpu++) {
754 if (!cpu_online(cpu) || cpu == this_cpu)
756 if (mm->context[cpu])
757 mm->context[cpu] = 0;
768 if (smp_call_function(ipi_flush_tlb_page, &data, 1)) {
769 printk(KERN_CRIT "flush_tlb_page: timed out\n");
774 EXPORT_SYMBOL(flush_tlb_page);
777 flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
779 /* On the Alpha we always flush the whole user tlb. */
780 flush_tlb_mm(vma->vm_mm);
782 EXPORT_SYMBOL(flush_tlb_range);
785 ipi_flush_icache_page(void *x)
787 struct mm_struct *mm = (struct mm_struct *) x;
788 if (mm == current->active_mm && !asn_locked())
789 __load_new_mm_context(mm);
795 flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
796 unsigned long addr, int len)
798 struct mm_struct *mm = vma->vm_mm;
800 if ((vma->vm_flags & VM_EXEC) == 0)
805 if (mm == current->active_mm) {
806 __load_new_mm_context(mm);
807 if (atomic_read(&mm->mm_users) <= 1) {
808 int cpu, this_cpu = smp_processor_id();
809 for (cpu = 0; cpu < NR_CPUS; cpu++) {
810 if (!cpu_online(cpu) || cpu == this_cpu)
812 if (mm->context[cpu])
813 mm->context[cpu] = 0;
820 if (smp_call_function(ipi_flush_icache_page, mm, 1)) {
821 printk(KERN_CRIT "flush_icache_page: timed out\n");