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
);
129 spinlock_t
*lock
= &per_cpu(ipi_lock
, this_cpu
);
130 spin_lock_irqsave(lock
, flags
);
131 ops
= p
->pending_ipi
;
133 spin_unlock_irqrestore(lock
, flags
);
135 mb(); /* Order bit clearing and data access. */
141 unsigned long which
= ffz(~ops
);
143 ops
&= ~(1 << which
);
147 smp_debug(100, KERN_DEBUG
"CPU%d IPI_NOP\n", this_cpu
);
151 smp_debug(100, KERN_DEBUG
"CPU%d IPI_RESCHEDULE\n", this_cpu
);
152 inc_irq_stat(irq_resched_count
);
157 smp_debug(100, KERN_DEBUG
"CPU%d IPI_CALL_FUNC\n", this_cpu
);
158 generic_smp_call_function_interrupt();
162 smp_debug(100, KERN_DEBUG
"CPU%d IPI_CPU_START\n", this_cpu
);
166 smp_debug(100, KERN_DEBUG
"CPU%d IPI_CPU_STOP\n", this_cpu
);
171 smp_debug(100, KERN_DEBUG
"CPU%d is alive!\n", this_cpu
);
175 printk(KERN_CRIT
"Unknown IPI num on CPU%d: %lu\n",
179 /* let in any pending interrupts */
189 ipi_send(int cpu
, enum ipi_message_type op
)
191 struct cpuinfo_parisc
*p
= &per_cpu(cpu_data
, cpu
);
192 spinlock_t
*lock
= &per_cpu(ipi_lock
, cpu
);
195 spin_lock_irqsave(lock
, flags
);
196 p
->pending_ipi
|= 1 << op
;
197 gsc_writel(IPI_IRQ
- CPU_IRQ_BASE
, p
->hpa
);
198 spin_unlock_irqrestore(lock
, flags
);
202 send_IPI_mask(const struct cpumask
*mask
, enum ipi_message_type op
)
206 for_each_cpu(cpu
, mask
)
211 send_IPI_single(int dest_cpu
, enum ipi_message_type op
)
213 BUG_ON(dest_cpu
== NO_PROC_ID
);
215 ipi_send(dest_cpu
, op
);
219 send_IPI_allbutself(enum ipi_message_type op
)
223 for_each_online_cpu(i
) {
224 if (i
!= smp_processor_id())
225 send_IPI_single(i
, op
);
231 smp_send_stop(void) { send_IPI_allbutself(IPI_CPU_STOP
); }
234 smp_send_reschedule(int cpu
) { send_IPI_single(cpu
, IPI_RESCHEDULE
); }
237 smp_send_all_nop(void)
239 send_IPI_allbutself(IPI_NOP
);
242 void arch_send_call_function_ipi_mask(const struct cpumask
*mask
)
244 send_IPI_mask(mask
, IPI_CALL_FUNC
);
247 void arch_send_call_function_single_ipi(int cpu
)
249 send_IPI_single(cpu
, IPI_CALL_FUNC
);
253 * Called by secondaries to update state and initialize CPU registers.
256 smp_cpu_init(int cpunum
)
258 extern int init_per_cpu(int); /* arch/parisc/kernel/processor.c */
259 extern void init_IRQ(void); /* arch/parisc/kernel/irq.c */
260 extern void start_cpu_itimer(void); /* arch/parisc/kernel/time.c */
262 /* Set modes and Enable floating point coprocessor */
263 (void) init_per_cpu(cpunum
);
265 disable_sr_hashing();
269 /* Well, support 2.4 linux scheme as well. */
270 if (cpu_online(cpunum
)) {
271 extern void machine_halt(void); /* arch/parisc.../process.c */
273 printk(KERN_CRIT
"CPU#%d already initialized!\n", cpunum
);
277 notify_cpu_starting(cpunum
);
279 set_cpu_online(cpunum
, true);
281 /* Initialise the idle task for this CPU */
282 atomic_inc(&init_mm
.mm_count
);
283 current
->active_mm
= &init_mm
;
285 enter_lazy_tlb(&init_mm
, current
);
287 init_IRQ(); /* make sure no IRQs are enabled or pending */
293 * Slaves start using C here. Indirectly called from smp_slave_stext.
294 * Do what start_kernel() and main() do for boot strap processor (aka monarch)
296 void __init
smp_callin(void)
298 int slave_id
= cpu_now_booting
;
300 smp_cpu_init(slave_id
);
303 flush_cache_all_local(); /* start with known state */
304 flush_tlb_all_local(NULL
);
306 local_irq_enable(); /* Interrupts have been off until now */
308 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE
);
311 panic("smp_callin() AAAAaaaaahhhh....\n");
315 * Bring one cpu online.
317 int smp_boot_one_cpu(int cpuid
, struct task_struct
*idle
)
319 const struct cpuinfo_parisc
*p
= &per_cpu(cpu_data
, cpuid
);
322 task_thread_info(idle
)->cpu
= cpuid
;
324 /* Let _start know what logical CPU we're booting
325 ** (offset into init_tasks[],cpu_data[])
327 cpu_now_booting
= cpuid
;
330 ** boot strap code needs to know the task address since
331 ** it also contains the process stack.
333 smp_init_current_idle_task
= idle
;
336 printk(KERN_INFO
"Releasing cpu %d now, hpa=%lx\n", cpuid
, p
->hpa
);
339 ** This gets PDC to release the CPU from a very tight loop.
341 ** From the PA-RISC 2.0 Firmware Architecture Reference Specification:
342 ** "The MEM_RENDEZ vector specifies the location of OS_RENDEZ which
343 ** is executed after receiving the rendezvous signal (an interrupt to
344 ** EIR{0}). MEM_RENDEZ is valid only when it is nonzero and the
345 ** contents of memory are valid."
347 gsc_writel(TIMER_IRQ
- CPU_IRQ_BASE
, p
->hpa
);
351 * OK, wait a bit for that CPU to finish staggering about.
352 * Slave will set a bit when it reaches smp_cpu_init().
353 * Once the "monarch CPU" sees the bit change, it can move on.
355 for (timeout
= 0; timeout
< 10000; timeout
++) {
356 if(cpu_online(cpuid
)) {
357 /* Which implies Slave has started up */
359 smp_init_current_idle_task
= NULL
;
365 printk(KERN_CRIT
"SMP: CPU:%d is stuck.\n", cpuid
);
369 /* Remember the Slave data */
370 smp_debug(100, KERN_DEBUG
"SMP: CPU:%d came alive after %ld _us\n",
371 cpuid
, timeout
* 100);
375 void __init
smp_prepare_boot_cpu(void)
377 int bootstrap_processor
= per_cpu(cpu_data
, 0).cpuid
;
379 /* Setup BSP mappings */
380 printk(KERN_INFO
"SMP: bootstrap CPU ID is %d\n", bootstrap_processor
);
382 set_cpu_online(bootstrap_processor
, true);
383 set_cpu_present(bootstrap_processor
, true);
389 ** inventory.c:do_inventory() hasn't yet been run and thus we
390 ** don't 'discover' the additional CPUs until later.
392 void __init
smp_prepare_cpus(unsigned int max_cpus
)
396 for_each_possible_cpu(cpu
)
397 spin_lock_init(&per_cpu(ipi_lock
, cpu
));
399 init_cpu_present(cpumask_of(0));
401 parisc_max_cpus
= max_cpus
;
403 printk(KERN_INFO
"SMP mode deactivated.\n");
407 void smp_cpus_done(unsigned int cpu_max
)
413 int __cpu_up(unsigned int cpu
, struct task_struct
*tidle
)
415 if (cpu
!= 0 && cpu
< parisc_max_cpus
)
416 smp_boot_one_cpu(cpu
, tidle
);
418 return cpu_online(cpu
) ? 0 : -ENOSYS
;
421 #ifdef CONFIG_PROC_FS
423 setup_profiling_timer(unsigned int multiplier
)