4 ** Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
5 ** Copyright (C) 1999 David Mosberger-Tang <davidm@hpl.hp.com>
6 ** Copyright (C) 2001,2004 Grant Grundler <grundler@parisc-linux.org>
8 ** Lots of stuff stolen from arch/alpha/kernel/smp.c
9 ** ...and then parisc stole from arch/ia64/kernel/smp.c. Thanks David! :^)
11 ** Thanks to John Curry and Ullas Ponnadi. I learned a lot from their work.
14 ** This program is free software; you can redistribute it and/or modify
15 ** it under the terms of the GNU General Public License as published by
16 ** the Free Software Foundation; either version 2 of the License, or
17 ** (at your option) any later version.
19 #include <linux/types.h>
20 #include <linux/spinlock.h>
22 #include <linux/kernel.h>
23 #include <linux/module.h>
24 #include <linux/sched.h>
25 #include <linux/init.h>
26 #include <linux/interrupt.h>
27 #include <linux/smp.h>
28 #include <linux/kernel_stat.h>
30 #include <linux/err.h>
31 #include <linux/delay.h>
32 #include <linux/bitops.h>
33 #include <linux/ftrace.h>
34 #include <linux/cpu.h>
36 #include <linux/atomic.h>
37 #include <asm/current.h>
38 #include <asm/delay.h>
39 #include <asm/tlbflush.h>
42 #include <asm/irq.h> /* for CPU_IRQ_REGION and friends */
43 #include <asm/mmu_context.h>
45 #include <asm/pgtable.h>
46 #include <asm/pgalloc.h>
47 #include <asm/processor.h>
48 #include <asm/ptrace.h>
49 #include <asm/unistd.h>
50 #include <asm/cacheflush.h>
54 static int smp_debug_lvl = 0;
55 #define smp_debug(lvl, printargs...) \
56 if (lvl >= smp_debug_lvl) \
59 #define smp_debug(lvl, ...) do { } while(0)
60 #endif /* DEBUG_SMP */
62 volatile struct task_struct *smp_init_current_idle_task;
64 /* track which CPU is booting */
65 static volatile int cpu_now_booting;
67 static int parisc_max_cpus = 1;
69 static DEFINE_PER_CPU(spinlock_t, ipi_lock);
71 enum ipi_message_type {
81 /********** SMP inter processor interrupt and communication routines */
83 #undef PER_CPU_IRQ_REGION
84 #ifdef PER_CPU_IRQ_REGION
85 /* XXX REVISIT Ignore for now.
86 ** *May* need this "hook" to register IPI handler
87 ** once we have perCPU ExtIntr switch tables.
92 #error verify IRQ_OFFSET(IPI_IRQ) is ipi_interrupt() in new IRQ region
94 if(cpu_online(cpuid) )
96 switch_to_idle_task(current);
105 ** Yoink this CPU from the runnable list...
111 /* REVISIT : redirect I/O Interrupts to another CPU? */
112 /* REVISIT : does PM *know* this CPU isn't available? */
113 set_cpu_online(smp_processor_id(), false);
120 irqreturn_t __irq_entry
121 ipi_interrupt(int irq, void *dev_id)
123 int this_cpu = smp_processor_id();
124 struct cpuinfo_parisc *p = &per_cpu(cpu_data, this_cpu);
128 /* Count this now; we may make a call that never returns. */
129 inc_irq_stat(irq_call_count);
131 mb(); /* Order interrupt and bit testing. */
134 spinlock_t *lock = &per_cpu(ipi_lock, this_cpu);
135 spin_lock_irqsave(lock, flags);
136 ops = p->pending_ipi;
138 spin_unlock_irqrestore(lock, flags);
140 mb(); /* Order bit clearing and data access. */
146 unsigned long which = ffz(~ops);
148 ops &= ~(1 << which);
152 smp_debug(100, KERN_DEBUG "CPU%d IPI_NOP\n", this_cpu);
156 smp_debug(100, KERN_DEBUG "CPU%d IPI_RESCHEDULE\n", this_cpu);
157 inc_irq_stat(irq_resched_count);
162 smp_debug(100, KERN_DEBUG "CPU%d IPI_CALL_FUNC\n", this_cpu);
163 generic_smp_call_function_interrupt();
167 smp_debug(100, KERN_DEBUG "CPU%d IPI_CPU_START\n", this_cpu);
171 smp_debug(100, KERN_DEBUG "CPU%d IPI_CPU_STOP\n", this_cpu);
176 smp_debug(100, KERN_DEBUG "CPU%d is alive!\n", this_cpu);
180 printk(KERN_CRIT "Unknown IPI num on CPU%d: %lu\n",
184 /* let in any pending interrupts */
194 ipi_send(int cpu, enum ipi_message_type op)
196 struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpu);
197 spinlock_t *lock = &per_cpu(ipi_lock, cpu);
200 spin_lock_irqsave(lock, flags);
201 p->pending_ipi |= 1 << op;
202 gsc_writel(IPI_IRQ - CPU_IRQ_BASE, p->hpa);
203 spin_unlock_irqrestore(lock, flags);
207 send_IPI_mask(const struct cpumask *mask, enum ipi_message_type op)
211 for_each_cpu(cpu, mask)
216 send_IPI_single(int dest_cpu, enum ipi_message_type op)
218 BUG_ON(dest_cpu == NO_PROC_ID);
220 ipi_send(dest_cpu, op);
224 send_IPI_allbutself(enum ipi_message_type op)
228 for_each_online_cpu(i) {
229 if (i != smp_processor_id())
230 send_IPI_single(i, op);
236 smp_send_stop(void) { send_IPI_allbutself(IPI_CPU_STOP); }
239 smp_send_start(void) { send_IPI_allbutself(IPI_CPU_START); }
242 smp_send_reschedule(int cpu) { send_IPI_single(cpu, IPI_RESCHEDULE); }
245 smp_send_all_nop(void)
247 send_IPI_allbutself(IPI_NOP);
250 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
252 send_IPI_mask(mask, IPI_CALL_FUNC);
255 void arch_send_call_function_single_ipi(int cpu)
257 send_IPI_single(cpu, IPI_CALL_FUNC);
261 * Called by secondaries to update state and initialize CPU registers.
264 smp_cpu_init(int cpunum)
266 extern int init_per_cpu(int); /* arch/parisc/kernel/processor.c */
267 extern void init_IRQ(void); /* arch/parisc/kernel/irq.c */
268 extern void start_cpu_itimer(void); /* arch/parisc/kernel/time.c */
270 /* Set modes and Enable floating point coprocessor */
271 (void) init_per_cpu(cpunum);
273 disable_sr_hashing();
277 /* Well, support 2.4 linux scheme as well. */
278 if (cpu_online(cpunum)) {
279 extern void machine_halt(void); /* arch/parisc.../process.c */
281 printk(KERN_CRIT "CPU#%d already initialized!\n", cpunum);
285 notify_cpu_starting(cpunum);
287 set_cpu_online(cpunum, true);
289 /* Initialise the idle task for this CPU */
290 atomic_inc(&init_mm.mm_count);
291 current->active_mm = &init_mm;
293 enter_lazy_tlb(&init_mm, current);
295 init_IRQ(); /* make sure no IRQs are enabled or pending */
301 * Slaves start using C here. Indirectly called from smp_slave_stext.
302 * Do what start_kernel() and main() do for boot strap processor (aka monarch)
304 void __init smp_callin(void)
306 int slave_id = cpu_now_booting;
308 smp_cpu_init(slave_id);
311 flush_cache_all_local(); /* start with known state */
312 flush_tlb_all_local(NULL);
314 local_irq_enable(); /* Interrupts have been off until now */
316 cpu_startup_entry(CPUHP_ONLINE);
319 panic("smp_callin() AAAAaaaaahhhh....\n");
323 * Bring one cpu online.
325 int smp_boot_one_cpu(int cpuid, struct task_struct *idle)
327 const struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpuid);
330 task_thread_info(idle)->cpu = cpuid;
332 /* Let _start know what logical CPU we're booting
333 ** (offset into init_tasks[],cpu_data[])
335 cpu_now_booting = cpuid;
338 ** boot strap code needs to know the task address since
339 ** it also contains the process stack.
341 smp_init_current_idle_task = idle ;
344 printk(KERN_INFO "Releasing cpu %d now, hpa=%lx\n", cpuid, p->hpa);
347 ** This gets PDC to release the CPU from a very tight loop.
349 ** From the PA-RISC 2.0 Firmware Architecture Reference Specification:
350 ** "The MEM_RENDEZ vector specifies the location of OS_RENDEZ which
351 ** is executed after receiving the rendezvous signal (an interrupt to
352 ** EIR{0}). MEM_RENDEZ is valid only when it is nonzero and the
353 ** contents of memory are valid."
355 gsc_writel(TIMER_IRQ - CPU_IRQ_BASE, p->hpa);
359 * OK, wait a bit for that CPU to finish staggering about.
360 * Slave will set a bit when it reaches smp_cpu_init().
361 * Once the "monarch CPU" sees the bit change, it can move on.
363 for (timeout = 0; timeout < 10000; timeout++) {
364 if(cpu_online(cpuid)) {
365 /* Which implies Slave has started up */
367 smp_init_current_idle_task = NULL;
373 printk(KERN_CRIT "SMP: CPU:%d is stuck.\n", cpuid);
377 /* Remember the Slave data */
378 smp_debug(100, KERN_DEBUG "SMP: CPU:%d came alive after %ld _us\n",
379 cpuid, timeout * 100);
383 void __init smp_prepare_boot_cpu(void)
385 int bootstrap_processor = per_cpu(cpu_data, 0).cpuid;
387 /* Setup BSP mappings */
388 printk(KERN_INFO "SMP: bootstrap CPU ID is %d\n", bootstrap_processor);
390 set_cpu_online(bootstrap_processor, true);
391 set_cpu_present(bootstrap_processor, true);
397 ** inventory.c:do_inventory() hasn't yet been run and thus we
398 ** don't 'discover' the additional CPUs until later.
400 void __init smp_prepare_cpus(unsigned int max_cpus)
404 for_each_possible_cpu(cpu)
405 spin_lock_init(&per_cpu(ipi_lock, cpu));
407 init_cpu_present(cpumask_of(0));
409 parisc_max_cpus = max_cpus;
411 printk(KERN_INFO "SMP mode deactivated.\n");
415 void smp_cpus_done(unsigned int cpu_max)
421 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
423 if (cpu != 0 && cpu < parisc_max_cpus)
424 smp_boot_one_cpu(cpu, tidle);
426 return cpu_online(cpu) ? 0 : -ENOSYS;
429 #ifdef CONFIG_PROC_FS
431 setup_profiling_timer(unsigned int multiplier)