void __init smp_prepare_cpus(unsigned int max_cpus)
{
int num_cpus, i;
/* Fixup boot cpu */
smp_store_cpu_info(smp_processor_id());
cpu_callin_map[smp_processor_id()] = 1;
smp_ops = ppc_md.smp_ops;
if (smp_ops == NULL) {
printk("SMP not supported on this machine.\n");
return;
}
/* Probe platform for CPUs: always linear. */
num_cpus = smp_ops->probe();
for (i = 0; i < num_cpus; ++i)
cpu_set(i, cpu_possible_map);
/* Backup CPU 0 state */
__save_cpu_setup();
if (smp_ops->space_timers)
smp_ops->space_timers(num_cpus);
}
void __init smp_boot_cpus(void)
{
extern struct task_struct *current_set[NR_CPUS];
int i, cpu_nr;
struct task_struct *p;
printk("Entering SMP Mode...\n");
smp_num_cpus = 1;
smp_store_cpu_info(0);
cpu_online_map = 1UL;
/*
* assume for now that the first cpu booted is
* cpu 0, the master -- Cort
*/
cpu_callin_map[0] = 1;
current->processor = 0;
for (i = 0; i < NR_CPUS; i++) {
prof_counter[i] = 1;
prof_multiplier[i] = 1;
}
/*
* XXX very rough, assumes 20 bus cycles to read a cache line,
* timebase increments every 4 bus cycles, 32kB L1 data cache.
*/
cacheflush_time = 5 * 1024;
smp_ops = ppc_md.smp_ops;
if (smp_ops == NULL) {
printk("SMP not supported on this machine.\n");
return;
}
#ifndef CONFIG_750_SMP
/* check for 750's, they just don't work with linux SMP.
* If you actually have 750 SMP hardware and want to try to get
* it to work, send me a patch to make it work and
* I'll make CONFIG_750_SMP a config option. -- Troy ([email protected])
*/
if ( PVR_VER(mfspr(PVR)) == 8 ){
printk("SMP not supported on 750 cpus. %s line %d\n",
__FILE__, __LINE__);
return;
}
#endif
/* Probe arch for CPUs */
cpu_nr = smp_ops->probe();
/* Backup CPU 0 state */
__save_cpu_setup();
/*
* only check for cpus we know exist. We keep the callin map
* with cpus at the bottom -- Cort
*/
if (cpu_nr > max_cpus)
cpu_nr = max_cpus;
for (i = 1; i < cpu_nr; i++) {
int c;
struct pt_regs regs;
/* create a process for the processor */
/* only regs.msr is actually used, and 0 is OK for it */
memset(®s, 0, sizeof(struct pt_regs));
if (do_fork(CLONE_VM|CLONE_PID, 0, ®s, 0) < 0)
panic("failed fork for CPU %d", i);
p = init_task.prev_task;
if (!p)
panic("No idle task for CPU %d", i);
init_idle(p, i);
unhash_process(p);
init_tasks[i] = p;
p->processor = i;
p->cpus_runnable = 1 << i; /* we schedule the first task manually */
current_set[i] = p;
/*
* There was a cache flush loop here to flush the cache
* to memory for the first 8MB of RAM. The cache flush
* has been pushed into the kick_cpu function for those
* platforms that need it.
*/
/* wake up cpus */
smp_ops->kick_cpu(i);
/*
* wait to see if the cpu made a callin (is actually up).
* use this value that I found through experimentation.
* -- Cort
*/
for ( c = 10000; c && !cpu_callin_map[i] ; c-- )
udelay(100);
if ( cpu_callin_map[i] )
{
char buf[32];
sprintf(buf, "found cpu %d", i);
if (ppc_md.progress) ppc_md.progress(buf, 0x350+i);
printk("Processor %d found.\n", i);
smp_num_cpus++;
} else {
char buf[32];
sprintf(buf, "didn't find cpu %d", i);
if (ppc_md.progress) ppc_md.progress(buf, 0x360+i);
printk("Processor %d is stuck.\n", i);
}
}
/* Setup CPU 0 last (important) */
smp_ops->setup_cpu(0);
if (smp_num_cpus < 2)
smp_tb_synchronized = 1;
}