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 unsigned long cache_decay_ticks = HZ/100;
46 cpumask_t cpu_online_map;
47 cpumask_t cpu_possible_map;
48 int smp_hw_index[NR_CPUS];
49 struct thread_info *secondary_ti;
51 EXPORT_SYMBOL(cpu_online_map);
52 EXPORT_SYMBOL(cpu_possible_map);
54 /* SMP operations for this machine */
55 static struct smp_ops_t *smp_ops;
57 /* all cpu mappings are 1-1 -- Cort */
58 volatile unsigned long cpu_callin_map[NR_CPUS];
60 int start_secondary(void *);
61 void smp_call_function_interrupt(void);
62 static int __smp_call_function(void (*func) (void *info), void *info,
63 int wait, int target);
65 /* Low level assembly function used to backup CPU 0 state */
66 extern void __save_cpu_setup(void);
68 /* Since OpenPIC has only 4 IPIs, we use slightly different message numbers.
70 * Make sure this matches openpic_request_IPIs in open_pic.c, or what shows up
71 * in /proc/interrupts will be wrong!!! --Troy */
72 #define PPC_MSG_CALL_FUNCTION 0
73 #define PPC_MSG_RESCHEDULE 1
74 #define PPC_MSG_INVALIDATE_TLB 2
75 #define PPC_MSG_XMON_BREAK 3
78 smp_message_pass(int target, int msg, unsigned long data, int wait)
81 atomic_inc(&ipi_sent);
82 smp_ops->message_pass(target,msg,data,wait);
89 void smp_message_recv(int msg, struct pt_regs *regs)
91 atomic_inc(&ipi_recv);
94 case PPC_MSG_CALL_FUNCTION:
95 smp_call_function_interrupt();
97 case PPC_MSG_RESCHEDULE:
100 case PPC_MSG_INVALIDATE_TLB:
104 case PPC_MSG_XMON_BREAK:
107 #endif /* CONFIG_XMON */
109 printk("SMP %d: smp_message_recv(): unknown msg %d\n",
110 smp_processor_id(), msg);
116 * 750's don't broadcast tlb invalidates so
117 * we have to emulate that behavior.
120 void smp_send_tlb_invalidate(int cpu)
122 if ( PVR_VER(mfspr(PVR)) == 8 )
123 smp_message_pass(MSG_ALL_BUT_SELF, PPC_MSG_INVALIDATE_TLB, 0, 0);
126 void smp_send_reschedule(int cpu)
129 * This is only used if `cpu' is running an idle task,
130 * so it will reschedule itself anyway...
132 * This isn't the case anymore since the other CPU could be
133 * sleeping and won't reschedule until the next interrupt (such
137 /* This is only used if `cpu' is running an idle task,
138 so it will reschedule itself anyway... */
139 smp_message_pass(cpu, PPC_MSG_RESCHEDULE, 0, 0);
143 void smp_send_xmon_break(int cpu)
145 smp_message_pass(cpu, PPC_MSG_XMON_BREAK, 0, 0);
147 #endif /* CONFIG_XMON */
149 static void stop_this_cpu(void *dummy)
156 void smp_send_stop(void)
158 smp_call_function(stop_this_cpu, NULL, 1, 0);
162 * Structure and data for smp_call_function(). This is designed to minimise
163 * static memory requirements. It also looks cleaner.
164 * Stolen from the i386 version.
166 static DEFINE_SPINLOCK(call_lock);
168 static struct call_data_struct {
169 void (*func) (void *info);
177 * this function sends a 'generic call function' IPI to all other CPUs
181 int smp_call_function(void (*func) (void *info), void *info, int nonatomic,
184 * [SUMMARY] Run a function on all other CPUs.
185 * <func> The function to run. This must be fast and non-blocking.
186 * <info> An arbitrary pointer to pass to the function.
187 * <nonatomic> currently unused.
188 * <wait> If true, wait (atomically) until function has completed on other CPUs.
189 * [RETURNS] 0 on success, else a negative status code. Does not return until
190 * remote CPUs are nearly ready to execute <<func>> or are or have executed.
192 * You must not call this function with disabled interrupts or from a
193 * hardware interrupt handler or from a bottom half handler.
196 /* FIXME: get cpu lock with hotplug cpus, or change this to
198 if (num_online_cpus() <= 1)
200 /* Can deadlock when called with interrupts disabled */
201 WARN_ON(irqs_disabled());
202 return __smp_call_function(func, info, wait, MSG_ALL_BUT_SELF);
205 static int __smp_call_function(void (*func) (void *info), void *info,
206 int wait, int target)
208 struct call_data_struct data;
213 if (target == MSG_ALL_BUT_SELF)
214 ncpus = num_online_cpus() - 1;
215 else if (target == MSG_ALL)
216 ncpus = num_online_cpus();
220 atomic_set(&data.started, 0);
223 atomic_set(&data.finished, 0);
225 spin_lock(&call_lock);
227 /* Send a message to all other CPUs and wait for them to respond */
228 smp_message_pass(target, PPC_MSG_CALL_FUNCTION, 0, 0);
230 /* Wait for response */
232 while (atomic_read(&data.started) != ncpus) {
233 if (--timeout == 0) {
234 printk("smp_call_function on cpu %d: other cpus not responding (%d)\n",
235 smp_processor_id(), atomic_read(&data.started));
244 while (atomic_read(&data.finished) != ncpus) {
245 if (--timeout == 0) {
246 printk("smp_call_function on cpu %d: other cpus not finishing (%d/%d)\n",
247 smp_processor_id(), atomic_read(&data.finished), atomic_read(&data.started));
257 spin_unlock(&call_lock);
261 void smp_call_function_interrupt(void)
263 void (*func) (void *info) = call_data->func;
264 void *info = call_data->info;
265 int wait = call_data->wait;
268 * Notify initiating CPU that I've grabbed the data and am
269 * about to execute the function
271 atomic_inc(&call_data->started);
273 * At this point the info structure may be out of scope unless wait==1
277 atomic_inc(&call_data->finished);
280 static void __devinit smp_store_cpu_info(int id)
282 struct cpuinfo_PPC *c = &cpu_data[id];
284 /* assume bogomips are same for everything */
285 c->loops_per_jiffy = loops_per_jiffy;
289 void __init smp_prepare_cpus(unsigned int max_cpus)
294 smp_store_cpu_info(smp_processor_id());
295 cpu_callin_map[smp_processor_id()] = 1;
297 smp_ops = ppc_md.smp_ops;
298 if (smp_ops == NULL) {
299 printk("SMP not supported on this machine.\n");
303 /* Probe platform for CPUs: always linear. */
304 num_cpus = smp_ops->probe();
305 for (i = 0; i < num_cpus; ++i)
306 cpu_set(i, cpu_possible_map);
308 /* Backup CPU 0 state */
311 if (smp_ops->space_timers)
312 smp_ops->space_timers(num_cpus);
315 void __devinit smp_prepare_boot_cpu(void)
317 cpu_set(smp_processor_id(), cpu_online_map);
318 cpu_set(smp_processor_id(), cpu_possible_map);
321 int __init setup_profiling_timer(unsigned int multiplier)
326 /* Processor coming up starts here */
327 int __devinit start_secondary(void *unused)
331 atomic_inc(&init_mm.mm_count);
332 current->active_mm = &init_mm;
334 cpu = smp_processor_id();
335 smp_store_cpu_info(cpu);
336 set_dec(tb_ticks_per_jiffy);
337 cpu_callin_map[cpu] = 1;
339 printk("CPU %i done callin...\n", cpu);
340 smp_ops->setup_cpu(cpu);
341 printk("CPU %i done setup...\n", cpu);
343 smp_ops->take_timebase();
344 printk("CPU %i done timebase take...\n", cpu);
350 int __cpu_up(unsigned int cpu)
352 struct task_struct *p;
356 /* create a process for the processor */
357 /* only regs.msr is actually used, and 0 is OK for it */
360 panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p));
361 secondary_ti = p->thread_info;
362 p->thread_info->cpu = cpu;
365 * There was a cache flush loop here to flush the cache
366 * to memory for the first 8MB of RAM. The cache flush
367 * has been pushed into the kick_cpu function for those
368 * platforms that need it.
372 smp_ops->kick_cpu(cpu);
375 * wait to see if the cpu made a callin (is actually up).
376 * use this value that I found through experimentation.
379 for (c = 1000; c && !cpu_callin_map[cpu]; c--)
382 if (!cpu_callin_map[cpu]) {
383 sprintf(buf, "didn't find cpu %u", cpu);
384 if (ppc_md.progress) ppc_md.progress(buf, 0x360+cpu);
385 printk("Processor %u is stuck.\n", cpu);
389 sprintf(buf, "found cpu %u", cpu);
390 if (ppc_md.progress) ppc_md.progress(buf, 0x350+cpu);
391 printk("Processor %d found.\n", cpu);
393 smp_ops->give_timebase();
394 cpu_set(cpu, cpu_online_map);
398 void smp_cpus_done(unsigned int max_cpus)
400 smp_ops->setup_cpu(0);