4 * Written by Cort Dougan (cort@cs.nmt.edu) borrowing a great
5 * deal of code from the sparc and intel versions.
7 * Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu>
11 #include <linux/config.h>
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/sched.h>
15 #include <linux/smp.h>
16 #include <linux/smp_lock.h>
17 #include <linux/interrupt.h>
18 #include <linux/kernel_stat.h>
19 #include <linux/delay.h>
20 #include <linux/init.h>
21 #include <linux/spinlock.h>
22 #include <linux/cache.h>
24 #include <asm/ptrace.h>
25 #include <asm/atomic.h>
28 #include <asm/pgtable.h>
32 #include <asm/residual.h>
34 #include <asm/thread_info.h>
35 #include <asm/tlbflush.h>
38 int smp_threads_ready;
39 volatile int smp_commenced;
40 int smp_tb_synchronized;
41 struct cpuinfo_PPC cpu_data[NR_CPUS];
42 struct klock_info_struct klock_info = { KLOCK_CLEAR, 0 };
45 DEFINE_PER_CPU(unsigned int, prof_multiplier);
46 DEFINE_PER_CPU(unsigned int, prof_counter);
47 unsigned long cache_decay_ticks = HZ/100;
48 cpumask_t cpu_online_map;
49 cpumask_t cpu_possible_map;
50 int smp_hw_index[NR_CPUS];
51 struct thread_info *secondary_ti;
53 EXPORT_SYMBOL(cpu_online_map);
54 EXPORT_SYMBOL(cpu_possible_map);
56 /* SMP operations for this machine */
57 static struct smp_ops_t *smp_ops;
59 /* all cpu mappings are 1-1 -- Cort */
60 volatile unsigned long cpu_callin_map[NR_CPUS];
62 int start_secondary(void *);
63 extern int cpu_idle(void *unused);
64 void smp_call_function_interrupt(void);
65 static int __smp_call_function(void (*func) (void *info), void *info,
66 int wait, int target);
68 /* Low level assembly function used to backup CPU 0 state */
69 extern void __save_cpu_setup(void);
71 /* Since OpenPIC has only 4 IPIs, we use slightly different message numbers.
73 * Make sure this matches openpic_request_IPIs in open_pic.c, or what shows up
74 * in /proc/interrupts will be wrong!!! --Troy */
75 #define PPC_MSG_CALL_FUNCTION 0
76 #define PPC_MSG_RESCHEDULE 1
77 #define PPC_MSG_INVALIDATE_TLB 2
78 #define PPC_MSG_XMON_BREAK 3
81 smp_message_pass(int target, int msg, unsigned long data, int wait)
84 atomic_inc(&ipi_sent);
85 smp_ops->message_pass(target,msg,data,wait);
92 void smp_local_timer_interrupt(struct pt_regs * regs)
94 int cpu = smp_processor_id();
96 if (!--per_cpu(prof_counter, cpu)) {
97 update_process_times(user_mode(regs));
98 per_cpu(prof_counter, cpu) = per_cpu(prof_multiplier, cpu);
102 void smp_message_recv(int msg, struct pt_regs *regs)
104 atomic_inc(&ipi_recv);
107 case PPC_MSG_CALL_FUNCTION:
108 smp_call_function_interrupt();
110 case PPC_MSG_RESCHEDULE:
113 case PPC_MSG_INVALIDATE_TLB:
117 case PPC_MSG_XMON_BREAK:
120 #endif /* CONFIG_XMON */
122 printk("SMP %d: smp_message_recv(): unknown msg %d\n",
123 smp_processor_id(), msg);
129 * 750's don't broadcast tlb invalidates so
130 * we have to emulate that behavior.
133 void smp_send_tlb_invalidate(int cpu)
135 if ( PVR_VER(mfspr(PVR)) == 8 )
136 smp_message_pass(MSG_ALL_BUT_SELF, PPC_MSG_INVALIDATE_TLB, 0, 0);
139 void smp_send_reschedule(int cpu)
142 * This is only used if `cpu' is running an idle task,
143 * so it will reschedule itself anyway...
145 * This isn't the case anymore since the other CPU could be
146 * sleeping and won't reschedule until the next interrupt (such
150 /* This is only used if `cpu' is running an idle task,
151 so it will reschedule itself anyway... */
152 smp_message_pass(cpu, PPC_MSG_RESCHEDULE, 0, 0);
156 void smp_send_xmon_break(int cpu)
158 smp_message_pass(cpu, PPC_MSG_XMON_BREAK, 0, 0);
160 #endif /* CONFIG_XMON */
162 static void stop_this_cpu(void *dummy)
169 void smp_send_stop(void)
171 smp_call_function(stop_this_cpu, NULL, 1, 0);
175 * Structure and data for smp_call_function(). This is designed to minimise
176 * static memory requirements. It also looks cleaner.
177 * Stolen from the i386 version.
179 static spinlock_t call_lock = SPIN_LOCK_UNLOCKED;
181 static struct call_data_struct {
182 void (*func) (void *info);
190 * this function sends a 'generic call function' IPI to all other CPUs
194 int smp_call_function(void (*func) (void *info), void *info, int nonatomic,
197 * [SUMMARY] Run a function on all other CPUs.
198 * <func> The function to run. This must be fast and non-blocking.
199 * <info> An arbitrary pointer to pass to the function.
200 * <nonatomic> currently unused.
201 * <wait> If true, wait (atomically) until function has completed on other CPUs.
202 * [RETURNS] 0 on success, else a negative status code. Does not return until
203 * remote CPUs are nearly ready to execute <<func>> or are or have executed.
205 * You must not call this function with disabled interrupts or from a
206 * hardware interrupt handler or from a bottom half handler.
209 /* FIXME: get cpu lock with hotplug cpus, or change this to
211 if (num_online_cpus() <= 1)
213 /* Can deadlock when called with interrupts disabled */
214 WARN_ON(irqs_disabled());
215 return __smp_call_function(func, info, wait, MSG_ALL_BUT_SELF);
218 static int __smp_call_function(void (*func) (void *info), void *info,
219 int wait, int target)
221 struct call_data_struct data;
226 if (target == MSG_ALL_BUT_SELF)
227 ncpus = num_online_cpus() - 1;
228 else if (target == MSG_ALL)
229 ncpus = num_online_cpus();
233 atomic_set(&data.started, 0);
236 atomic_set(&data.finished, 0);
238 spin_lock(&call_lock);
240 /* Send a message to all other CPUs and wait for them to respond */
241 smp_message_pass(target, PPC_MSG_CALL_FUNCTION, 0, 0);
243 /* Wait for response */
245 while (atomic_read(&data.started) != ncpus) {
246 if (--timeout == 0) {
247 printk("smp_call_function on cpu %d: other cpus not responding (%d)\n",
248 smp_processor_id(), atomic_read(&data.started));
257 while (atomic_read(&data.finished) != ncpus) {
258 if (--timeout == 0) {
259 printk("smp_call_function on cpu %d: other cpus not finishing (%d/%d)\n",
260 smp_processor_id(), atomic_read(&data.finished), atomic_read(&data.started));
270 spin_unlock(&call_lock);
274 void smp_call_function_interrupt(void)
276 void (*func) (void *info) = call_data->func;
277 void *info = call_data->info;
278 int wait = call_data->wait;
281 * Notify initiating CPU that I've grabbed the data and am
282 * about to execute the function
284 atomic_inc(&call_data->started);
286 * At this point the info structure may be out of scope unless wait==1
290 atomic_inc(&call_data->finished);
293 static void __devinit smp_store_cpu_info(int id)
295 struct cpuinfo_PPC *c = &cpu_data[id];
297 /* assume bogomips are same for everything */
298 c->loops_per_jiffy = loops_per_jiffy;
300 per_cpu(prof_counter, id) = 1;
301 per_cpu(prof_multiplier, id) = 1;
304 void __init smp_prepare_cpus(unsigned int max_cpus)
309 smp_store_cpu_info(smp_processor_id());
310 cpu_callin_map[smp_processor_id()] = 1;
312 smp_ops = ppc_md.smp_ops;
313 if (smp_ops == NULL) {
314 printk("SMP not supported on this machine.\n");
318 /* Probe platform for CPUs: always linear. */
319 num_cpus = smp_ops->probe();
320 for (i = 0; i < num_cpus; ++i)
321 cpu_set(i, cpu_possible_map);
323 /* Backup CPU 0 state */
326 if (smp_ops->space_timers)
327 smp_ops->space_timers(num_cpus);
330 void __devinit smp_prepare_boot_cpu(void)
332 cpu_set(smp_processor_id(), cpu_online_map);
333 cpu_set(smp_processor_id(), cpu_possible_map);
336 int __init setup_profiling_timer(unsigned int multiplier)
341 /* Processor coming up starts here */
342 int __devinit start_secondary(void *unused)
346 atomic_inc(&init_mm.mm_count);
347 current->active_mm = &init_mm;
349 cpu = smp_processor_id();
350 smp_store_cpu_info(cpu);
351 set_dec(tb_ticks_per_jiffy);
352 cpu_callin_map[cpu] = 1;
354 printk("CPU %i done callin...\n", cpu);
355 smp_ops->setup_cpu(cpu);
356 printk("CPU %i done setup...\n", cpu);
358 smp_ops->take_timebase();
359 printk("CPU %i done timebase take...\n", cpu);
361 return cpu_idle(NULL);
364 int __cpu_up(unsigned int cpu)
366 struct task_struct *p;
370 /* create a process for the processor */
371 /* only regs.msr is actually used, and 0 is OK for it */
374 panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p));
375 secondary_ti = p->thread_info;
376 p->thread_info->cpu = cpu;
379 * There was a cache flush loop here to flush the cache
380 * to memory for the first 8MB of RAM. The cache flush
381 * has been pushed into the kick_cpu function for those
382 * platforms that need it.
386 smp_ops->kick_cpu(cpu);
389 * wait to see if the cpu made a callin (is actually up).
390 * use this value that I found through experimentation.
393 for (c = 1000; c && !cpu_callin_map[cpu]; c--)
396 if (!cpu_callin_map[cpu]) {
397 sprintf(buf, "didn't find cpu %u", cpu);
398 if (ppc_md.progress) ppc_md.progress(buf, 0x360+cpu);
399 printk("Processor %u is stuck.\n", cpu);
403 sprintf(buf, "found cpu %u", cpu);
404 if (ppc_md.progress) ppc_md.progress(buf, 0x350+cpu);
405 printk("Processor %d found.\n", cpu);
407 smp_ops->give_timebase();
408 cpu_set(cpu, cpu_online_map);
412 void smp_cpus_done(unsigned int max_cpus)
414 smp_ops->setup_cpu(0);