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/mm.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>
35 #include <linux/kgdb.h>
37 #include <linux/atomic.h>
38 #include <asm/current.h>
39 #include <asm/delay.h>
40 #include <asm/tlbflush.h>
43 #include <asm/irq.h> /* for CPU_IRQ_REGION and friends */
44 #include <asm/mmu_context.h>
46 #include <asm/pgtable.h>
47 #include <asm/pgalloc.h>
48 #include <asm/processor.h>
49 #include <asm/ptrace.h>
50 #include <asm/unistd.h>
51 #include <asm/cacheflush.h>
55 static int smp_debug_lvl = 0;
56 #define smp_debug(lvl, printargs...) \
57 if (lvl >= smp_debug_lvl) \
60 #define smp_debug(lvl, ...) do { } while(0)
61 #endif /* DEBUG_SMP */
63 volatile struct task_struct *smp_init_current_idle_task;
65 /* track which CPU is booting */
66 static volatile int cpu_now_booting;
68 static int parisc_max_cpus = 1;
70 static DEFINE_PER_CPU(spinlock_t, ipi_lock);
72 enum ipi_message_type {
85 /********** SMP inter processor interrupt and communication routines */
87 #undef PER_CPU_IRQ_REGION
88 #ifdef PER_CPU_IRQ_REGION
89 /* XXX REVISIT Ignore for now.
90 ** *May* need this "hook" to register IPI handler
91 ** once we have perCPU ExtIntr switch tables.
96 #error verify IRQ_OFFSET(IPI_IRQ) is ipi_interrupt() in new IRQ region
98 if(cpu_online(cpuid) )
100 switch_to_idle_task(current);
109 ** Yoink this CPU from the runnable list...
115 /* REVISIT : redirect I/O Interrupts to another CPU? */
116 /* REVISIT : does PM *know* this CPU isn't available? */
117 set_cpu_online(smp_processor_id(), false);
124 irqreturn_t __irq_entry
125 ipi_interrupt(int irq, void *dev_id)
127 int this_cpu = smp_processor_id();
128 struct cpuinfo_parisc *p = &per_cpu(cpu_data, this_cpu);
133 spinlock_t *lock = &per_cpu(ipi_lock, this_cpu);
134 spin_lock_irqsave(lock, flags);
135 ops = p->pending_ipi;
137 spin_unlock_irqrestore(lock, flags);
139 mb(); /* Order bit clearing and data access. */
145 unsigned long which = ffz(~ops);
147 ops &= ~(1 << which);
151 smp_debug(100, KERN_DEBUG "CPU%d IPI_NOP\n", this_cpu);
155 smp_debug(100, KERN_DEBUG "CPU%d IPI_RESCHEDULE\n", this_cpu);
156 inc_irq_stat(irq_resched_count);
161 smp_debug(100, KERN_DEBUG "CPU%d IPI_CALL_FUNC\n", this_cpu);
162 generic_smp_call_function_interrupt();
166 smp_debug(100, KERN_DEBUG "CPU%d IPI_CPU_START\n", this_cpu);
170 smp_debug(100, KERN_DEBUG "CPU%d IPI_CPU_STOP\n", this_cpu);
175 smp_debug(100, KERN_DEBUG "CPU%d is alive!\n", this_cpu);
179 smp_debug(100, KERN_DEBUG "CPU%d ENTER_KGDB\n", this_cpu);
180 kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
184 printk(KERN_CRIT "Unknown IPI num on CPU%d: %lu\n",
188 /* let in any pending interrupts */
198 ipi_send(int cpu, enum ipi_message_type op)
200 struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpu);
201 spinlock_t *lock = &per_cpu(ipi_lock, cpu);
204 spin_lock_irqsave(lock, flags);
205 p->pending_ipi |= 1 << op;
206 gsc_writel(IPI_IRQ - CPU_IRQ_BASE, p->hpa);
207 spin_unlock_irqrestore(lock, flags);
211 send_IPI_mask(const struct cpumask *mask, enum ipi_message_type op)
215 for_each_cpu(cpu, mask)
220 send_IPI_single(int dest_cpu, enum ipi_message_type op)
222 BUG_ON(dest_cpu == NO_PROC_ID);
224 ipi_send(dest_cpu, op);
228 send_IPI_allbutself(enum ipi_message_type op)
232 for_each_online_cpu(i) {
233 if (i != smp_processor_id())
234 send_IPI_single(i, op);
239 void kgdb_roundup_cpus(void)
241 send_IPI_allbutself(IPI_ENTER_KGDB);
246 smp_send_stop(void) { send_IPI_allbutself(IPI_CPU_STOP); }
249 smp_send_reschedule(int cpu) { send_IPI_single(cpu, IPI_RESCHEDULE); }
252 smp_send_all_nop(void)
254 send_IPI_allbutself(IPI_NOP);
257 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
259 send_IPI_mask(mask, IPI_CALL_FUNC);
262 void arch_send_call_function_single_ipi(int cpu)
264 send_IPI_single(cpu, IPI_CALL_FUNC);
268 * Called by secondaries to update state and initialize CPU registers.
271 smp_cpu_init(int cpunum)
273 extern void init_IRQ(void); /* arch/parisc/kernel/irq.c */
274 extern void start_cpu_itimer(void); /* arch/parisc/kernel/time.c */
276 /* Set modes and Enable floating point coprocessor */
277 init_per_cpu(cpunum);
279 disable_sr_hashing();
283 /* Well, support 2.4 linux scheme as well. */
284 if (cpu_online(cpunum)) {
285 extern void machine_halt(void); /* arch/parisc.../process.c */
287 printk(KERN_CRIT "CPU#%d already initialized!\n", cpunum);
291 notify_cpu_starting(cpunum);
293 set_cpu_online(cpunum, true);
295 /* Initialise the idle task for this CPU */
297 current->active_mm = &init_mm;
299 enter_lazy_tlb(&init_mm, current);
301 init_IRQ(); /* make sure no IRQs are enabled or pending */
307 * Slaves start using C here. Indirectly called from smp_slave_stext.
308 * Do what start_kernel() and main() do for boot strap processor (aka monarch)
310 void __init smp_callin(void)
312 int slave_id = cpu_now_booting;
314 smp_cpu_init(slave_id);
317 flush_cache_all_local(); /* start with known state */
318 flush_tlb_all_local(NULL);
320 local_irq_enable(); /* Interrupts have been off until now */
322 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
325 panic("smp_callin() AAAAaaaaahhhh....\n");
329 * Bring one cpu online.
331 int smp_boot_one_cpu(int cpuid, struct task_struct *idle)
333 const struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpuid);
336 task_thread_info(idle)->cpu = cpuid;
338 /* Let _start know what logical CPU we're booting
339 ** (offset into init_tasks[],cpu_data[])
341 cpu_now_booting = cpuid;
344 ** boot strap code needs to know the task address since
345 ** it also contains the process stack.
347 smp_init_current_idle_task = idle ;
350 printk(KERN_INFO "Releasing cpu %d now, hpa=%lx\n", cpuid, p->hpa);
353 ** This gets PDC to release the CPU from a very tight loop.
355 ** From the PA-RISC 2.0 Firmware Architecture Reference Specification:
356 ** "The MEM_RENDEZ vector specifies the location of OS_RENDEZ which
357 ** is executed after receiving the rendezvous signal (an interrupt to
358 ** EIR{0}). MEM_RENDEZ is valid only when it is nonzero and the
359 ** contents of memory are valid."
361 gsc_writel(TIMER_IRQ - CPU_IRQ_BASE, p->hpa);
365 * OK, wait a bit for that CPU to finish staggering about.
366 * Slave will set a bit when it reaches smp_cpu_init().
367 * Once the "monarch CPU" sees the bit change, it can move on.
369 for (timeout = 0; timeout < 10000; timeout++) {
370 if(cpu_online(cpuid)) {
371 /* Which implies Slave has started up */
373 smp_init_current_idle_task = NULL;
379 printk(KERN_CRIT "SMP: CPU:%d is stuck.\n", cpuid);
383 /* Remember the Slave data */
384 smp_debug(100, KERN_DEBUG "SMP: CPU:%d came alive after %ld _us\n",
385 cpuid, timeout * 100);
389 void __init smp_prepare_boot_cpu(void)
391 int bootstrap_processor = per_cpu(cpu_data, 0).cpuid;
393 /* Setup BSP mappings */
394 printk(KERN_INFO "SMP: bootstrap CPU ID is %d\n", bootstrap_processor);
396 set_cpu_online(bootstrap_processor, true);
397 set_cpu_present(bootstrap_processor, true);
403 ** inventory.c:do_inventory() hasn't yet been run and thus we
404 ** don't 'discover' the additional CPUs until later.
406 void __init smp_prepare_cpus(unsigned int max_cpus)
410 for_each_possible_cpu(cpu)
411 spin_lock_init(&per_cpu(ipi_lock, cpu));
413 init_cpu_present(cpumask_of(0));
415 parisc_max_cpus = max_cpus;
417 printk(KERN_INFO "SMP mode deactivated.\n");
421 void smp_cpus_done(unsigned int cpu_max)
427 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
429 if (cpu != 0 && cpu < parisc_max_cpus && smp_boot_one_cpu(cpu, tidle))
432 return cpu_online(cpu) ? 0 : -ENOSYS;
435 #ifdef CONFIG_PROC_FS
436 int setup_profiling_timer(unsigned int multiplier)