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>
35 #include <linux/atomic.h>
36 #include <asm/current.h>
37 #include <asm/delay.h>
38 #include <asm/tlbflush.h>
41 #include <asm/irq.h> /* for CPU_IRQ_REGION and friends */
42 #include <asm/mmu_context.h>
44 #include <asm/pgtable.h>
45 #include <asm/pgalloc.h>
46 #include <asm/processor.h>
47 #include <asm/ptrace.h>
48 #include <asm/unistd.h>
49 #include <asm/cacheflush.h>
53 static int smp_debug_lvl
= 0;
54 #define smp_debug(lvl, printargs...) \
55 if (lvl >= smp_debug_lvl) \
58 #define smp_debug(lvl, ...) do { } while(0)
59 #endif /* DEBUG_SMP */
61 volatile struct task_struct
*smp_init_current_idle_task
;
63 /* track which CPU is booting */
64 static volatile int cpu_now_booting __cpuinitdata
;
66 static int parisc_max_cpus __cpuinitdata
= 1;
68 static DEFINE_PER_CPU(spinlock_t
, ipi_lock
);
70 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. */
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
);
161 smp_debug(100, KERN_DEBUG
"CPU%d IPI_CALL_FUNC\n", this_cpu
);
162 generic_smp_call_function_interrupt();
165 case IPI_CALL_FUNC_SINGLE
:
166 smp_debug(100, KERN_DEBUG
"CPU%d IPI_CALL_FUNC_SINGLE\n", this_cpu
);
167 generic_smp_call_function_single_interrupt();
171 smp_debug(100, KERN_DEBUG
"CPU%d IPI_CPU_START\n", this_cpu
);
175 smp_debug(100, KERN_DEBUG
"CPU%d IPI_CPU_STOP\n", this_cpu
);
180 smp_debug(100, KERN_DEBUG
"CPU%d is alive!\n", this_cpu
);
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
);
240 smp_send_stop(void) { send_IPI_allbutself(IPI_CPU_STOP
); }
243 smp_send_start(void) { send_IPI_allbutself(IPI_CPU_START
); }
246 smp_send_reschedule(int cpu
) { send_IPI_single(cpu
, IPI_RESCHEDULE
); }
249 smp_send_all_nop(void)
251 send_IPI_allbutself(IPI_NOP
);
254 void arch_send_call_function_ipi_mask(const struct cpumask
*mask
)
256 send_IPI_mask(mask
, IPI_CALL_FUNC
);
259 void arch_send_call_function_single_ipi(int cpu
)
261 send_IPI_single(cpu
, IPI_CALL_FUNC_SINGLE
);
265 * Flush all other CPU's tlb and then mine. Do this with on_each_cpu()
266 * as we want to ensure all TLB's flushed before proceeding.
270 smp_flush_tlb_all(void)
272 on_each_cpu(flush_tlb_all_local
, NULL
, 1);
276 * Called by secondaries to update state and initialize CPU registers.
279 smp_cpu_init(int cpunum
)
281 extern int init_per_cpu(int); /* arch/parisc/kernel/processor.c */
282 extern void init_IRQ(void); /* arch/parisc/kernel/irq.c */
283 extern void start_cpu_itimer(void); /* arch/parisc/kernel/time.c */
285 /* Set modes and Enable floating point coprocessor */
286 (void) init_per_cpu(cpunum
);
288 disable_sr_hashing();
292 /* Well, support 2.4 linux scheme as well. */
293 if (cpu_isset(cpunum
, cpu_online_map
))
295 extern void machine_halt(void); /* arch/parisc.../process.c */
297 printk(KERN_CRIT
"CPU#%d already initialized!\n", cpunum
);
300 set_cpu_online(cpunum
, true);
302 /* Initialise the idle task for this CPU */
303 atomic_inc(&init_mm
.mm_count
);
304 current
->active_mm
= &init_mm
;
306 enter_lazy_tlb(&init_mm
, current
);
308 init_IRQ(); /* make sure no IRQs are enabled or pending */
314 * Slaves start using C here. Indirectly called from smp_slave_stext.
315 * Do what start_kernel() and main() do for boot strap processor (aka monarch)
317 void __init
smp_callin(void)
319 int slave_id
= cpu_now_booting
;
321 smp_cpu_init(slave_id
);
324 flush_cache_all_local(); /* start with known state */
325 flush_tlb_all_local(NULL
);
327 local_irq_enable(); /* Interrupts have been off until now */
329 cpu_idle(); /* Wait for timer to schedule some work */
332 panic("smp_callin() AAAAaaaaahhhh....\n");
336 * Bring one cpu online.
338 int __cpuinit
smp_boot_one_cpu(int cpuid
)
340 const struct cpuinfo_parisc
*p
= &per_cpu(cpu_data
, cpuid
);
341 struct task_struct
*idle
;
345 * Create an idle task for this CPU. Note the address wed* give
346 * to kernel_thread is irrelevant -- it's going to start
347 * where OS_BOOT_RENDEVZ vector in SAL says to start. But
348 * this gets all the other task-y sort of data structures set
349 * up like we wish. We need to pull the just created idle task
350 * off the run queue and stuff it into the init_tasks[] array.
354 idle
= fork_idle(cpuid
);
356 panic("SMP: fork failed for CPU:%d", cpuid
);
358 task_thread_info(idle
)->cpu
= cpuid
;
360 /* Let _start know what logical CPU we're booting
361 ** (offset into init_tasks[],cpu_data[])
363 cpu_now_booting
= cpuid
;
366 ** boot strap code needs to know the task address since
367 ** it also contains the process stack.
369 smp_init_current_idle_task
= idle
;
372 printk(KERN_INFO
"Releasing cpu %d now, hpa=%lx\n", cpuid
, p
->hpa
);
375 ** This gets PDC to release the CPU from a very tight loop.
377 ** From the PA-RISC 2.0 Firmware Architecture Reference Specification:
378 ** "The MEM_RENDEZ vector specifies the location of OS_RENDEZ which
379 ** is executed after receiving the rendezvous signal (an interrupt to
380 ** EIR{0}). MEM_RENDEZ is valid only when it is nonzero and the
381 ** contents of memory are valid."
383 gsc_writel(TIMER_IRQ
- CPU_IRQ_BASE
, p
->hpa
);
387 * OK, wait a bit for that CPU to finish staggering about.
388 * Slave will set a bit when it reaches smp_cpu_init().
389 * Once the "monarch CPU" sees the bit change, it can move on.
391 for (timeout
= 0; timeout
< 10000; timeout
++) {
392 if(cpu_online(cpuid
)) {
393 /* Which implies Slave has started up */
395 smp_init_current_idle_task
= NULL
;
402 put_task_struct(idle
);
405 printk(KERN_CRIT
"SMP: CPU:%d is stuck.\n", cpuid
);
409 /* Remember the Slave data */
410 smp_debug(100, KERN_DEBUG
"SMP: CPU:%d came alive after %ld _us\n",
411 cpuid
, timeout
* 100);
415 void __init
smp_prepare_boot_cpu(void)
417 int bootstrap_processor
= per_cpu(cpu_data
, 0).cpuid
;
419 /* Setup BSP mappings */
420 printk(KERN_INFO
"SMP: bootstrap CPU ID is %d\n", bootstrap_processor
);
422 set_cpu_online(bootstrap_processor
, true);
423 set_cpu_present(bootstrap_processor
, true);
429 ** inventory.c:do_inventory() hasn't yet been run and thus we
430 ** don't 'discover' the additional CPUs until later.
432 void __init
smp_prepare_cpus(unsigned int max_cpus
)
436 for_each_possible_cpu(cpu
)
437 spin_lock_init(&per_cpu(ipi_lock
, cpu
));
439 init_cpu_present(cpumask_of(0));
441 parisc_max_cpus
= max_cpus
;
443 printk(KERN_INFO
"SMP mode deactivated.\n");
447 void smp_cpus_done(unsigned int cpu_max
)
453 int __cpuinit
__cpu_up(unsigned int cpu
)
455 if (cpu
!= 0 && cpu
< parisc_max_cpus
)
456 smp_boot_one_cpu(cpu
);
458 return cpu_online(cpu
) ? 0 : -ENOSYS
;
461 #ifdef CONFIG_PROC_FS
463 setup_profiling_timer(unsigned int multiplier
)