smp.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 727 行 · 第 1/2 页

	/*  Send a message to all other CPUs and wait for them to respond  */
	send_IPI_allbutself(IPI_CALL_FUNC);

	/*  Wait for response  */
	timeout = jiffies + HZ;
	while ( (atomic_read (&data.unstarted_count) > 0) &&
		time_before (jiffies, timeout) )
		barrier ();

	/* We either got one or timed out. Release the lock */

	mb();
	smp_call_function_data = NULL;
	if (atomic_read (&data.unstarted_count) > 0) {
		printk(KERN_CRIT "SMP CALL FUNCTION TIMED OUT! (cpu=%d)\n",
		      smp_processor_id());
		return -ETIMEDOUT;
	}

	while (wait && atomic_read (&data.unfinished_count) > 0)
			barrier ();

	return 0;
}

EXPORT_SYMBOL(smp_call_function);

/*
 * Flush all other CPU's tlb and then mine.  Do this with on_each_cpu()
 * as we want to ensure all TLB's flushed before proceeding.
 */

extern void flush_tlb_all_local(void);

void
smp_flush_tlb_all(void)
{
	on_each_cpu((void (*)(void *))flush_tlb_all_local, NULL, 1, 1);
}


void 
smp_do_timer(struct pt_regs *regs)
{
	int cpu = smp_processor_id();
	struct cpuinfo_parisc *data = &cpu_data[cpu];

        if (!--data->prof_counter) {
		data->prof_counter = data->prof_multiplier;
		update_process_times(user_mode(regs));
	}
}

/*
 * Called by secondaries to update state and initialize CPU registers.
 */
static void __init
smp_cpu_init(int cpunum)
{
	extern int init_per_cpu(int);  /* arch/parisc/kernel/setup.c */
	extern void init_IRQ(void);    /* arch/parisc/kernel/irq.c */

	/* Set modes and Enable floating point coprocessor */
	(void) init_per_cpu(cpunum);

	disable_sr_hashing();

	mb();

	/* Well, support 2.4 linux scheme as well. */
	if (cpu_test_and_set(cpunum, cpu_online_map))
	{
		extern void machine_halt(void); /* arch/parisc.../process.c */

		printk(KERN_CRIT "CPU#%d already initialized!\n", cpunum);
		machine_halt();
	}  

	/* Initialise the idle task for this CPU */
	atomic_inc(&init_mm.mm_count);
	current->active_mm = &init_mm;
	if(current->mm)
		BUG();
	enter_lazy_tlb(&init_mm, current);

	init_IRQ();   /* make sure no IRQ's are enabled or pending */
}


/*
 * Slaves start using C here. Indirectly called from smp_slave_stext.
 * Do what start_kernel() and main() do for boot strap processor (aka monarch)
 */
void __init smp_callin(void)
{
	extern void cpu_idle(void);	/* arch/parisc/kernel/process.c */
	int slave_id = cpu_now_booting;
#if 0
	void *istack;
#endif

	smp_cpu_init(slave_id);

#if 0	/* NOT WORKING YET - see entry.S */
	istack = (void *)__get_free_pages(GFP_KERNEL,ISTACK_ORDER);
	if (istack == NULL) {
	    printk(KERN_CRIT "Failed to allocate interrupt stack for cpu %d\n",slave_id);
	    BUG();
	}
	mtctl(istack,31);
#endif

	flush_cache_all_local(); /* start with known state */
	flush_tlb_all_local();

	local_irq_enable();  /* Interrupts have been off until now */

	cpu_idle();      /* Wait for timer to schedule some work */

	/* NOTREACHED */
	panic("smp_callin() AAAAaaaaahhhh....\n");
}

/*
 * Bring one cpu online.
 */
int __init smp_boot_one_cpu(int cpuid)
{
	struct task_struct *idle;
	long timeout;

	/* 
	 * Create an idle task for this CPU.  Note the address wed* give 
	 * to kernel_thread is irrelevant -- it's going to start
	 * where OS_BOOT_RENDEVZ vector in SAL says to start.  But
	 * this gets all the other task-y sort of data structures set
	 * up like we wish.   We need to pull the just created idle task 
	 * off the run queue and stuff it into the init_tasks[] array.  
	 * Sheesh . . .
	 */

	idle = fork_idle(cpuid);
	if (IS_ERR(idle))
		panic("SMP: fork failed for CPU:%d", cpuid);

	idle->thread_info->cpu = cpuid;

	/* Let _start know what logical CPU we're booting
	** (offset into init_tasks[],cpu_data[])
	*/
	cpu_now_booting = cpuid;

	/* 
	** boot strap code needs to know the task address since
	** it also contains the process stack.
	*/
	smp_init_current_idle_task = idle ;
	mb();

	printk("Releasing cpu %d now, hpa=%lx\n", cpuid, cpu_data[cpuid].hpa);

	/*
	** This gets PDC to release the CPU from a very tight loop.
	**
	** From the PA-RISC 2.0 Firmware Architecture Reference Specification:
	** "The MEM_RENDEZ vector specifies the location of OS_RENDEZ which 
	** is executed after receiving the rendezvous signal (an interrupt to 
	** EIR{0}). MEM_RENDEZ is valid only when it is nonzero and the 
	** contents of memory are valid."
	*/
	__raw_writel(IRQ_OFFSET(TIMER_IRQ), cpu_data[cpuid].hpa);
	mb();

	/* 
	 * OK, wait a bit for that CPU to finish staggering about. 
	 * Slave will set a bit when it reaches smp_cpu_init().
	 * Once the "monarch CPU" sees the bit change, it can move on.
	 */
	for (timeout = 0; timeout < 10000; timeout++) {
		if(cpu_online(cpuid)) {
			/* Which implies Slave has started up */
			cpu_now_booting = 0;
			smp_init_current_idle_task = NULL;
			goto alive ;
		}
		udelay(100);
		barrier();
	}

	put_task_struct(idle);
	idle = NULL;

	printk(KERN_CRIT "SMP: CPU:%d is stuck.\n", cpuid);
	return -1;

alive:
	/* Remember the Slave data */
#if (kDEBUG>=100)
	printk(KERN_DEBUG "SMP: CPU:%d came alive after %ld _us\n",
		cpuid, timeout * 100);
#endif /* kDEBUG */
#ifdef ENTRY_SYS_CPUS
	cpu_data[cpuid].state = STATE_RUNNING;
#endif
	return 0;
}

void __devinit smp_prepare_boot_cpu(void)
{
	int bootstrap_processor=cpu_data[0].cpuid;	/* CPU ID of BSP */

#ifdef ENTRY_SYS_CPUS
	cpu_data[0].state = STATE_RUNNING;
#endif

	/* Setup BSP mappings */
	printk("SMP: bootstrap CPU ID is %d\n",bootstrap_processor);

	cpu_set(bootstrap_processor, cpu_online_map);
	cpu_set(bootstrap_processor, cpu_present_map);

	cache_decay_ticks = HZ/100;	/* FIXME very rough.  */
}



/*
** inventory.c:do_inventory() hasn't yet been run and thus we
** don't 'discover' the additional CPU's until later.
*/
void __init smp_prepare_cpus(unsigned int max_cpus)
{
	cpus_clear(cpu_present_map);
	cpu_set(0, cpu_present_map);

	parisc_max_cpus = max_cpus;
	if (!max_cpus)
		printk(KERN_INFO "SMP mode deactivated.\n");
}


void smp_cpus_done(unsigned int cpu_max)
{
	return;
}


int __devinit __cpu_up(unsigned int cpu)
{
	if (cpu != 0 && cpu < parisc_max_cpus)
		smp_boot_one_cpu(cpu);

	return cpu_online(cpu) ? 0 : -ENOSYS;
}



#ifdef ENTRY_SYS_CPUS
/* Code goes along with:
**    entry.s:        ENTRY_NAME(sys_cpus)   / * 215, for cpu stat * /
*/
int sys_cpus(int argc, char **argv)
{
	int i,j=0;
	extern int current_pid(int cpu);

	if( argc > 2 ) {
		printk("sys_cpus:Only one argument supported\n");
		return (-1);
	}
	if ( argc == 1 ){
	
#ifdef DUMP_MORE_STATE
		for(i=0; i<NR_CPUS; i++) {
			int cpus_per_line = 4;
			if(cpu_online(i)) {
				if (j++ % cpus_per_line)
					printk(" %3d",i);
				else
					printk("\n %3d",i);
			}
		}
		printk("\n"); 
#else
	    	printk("\n 0\n"); 
#endif
	} else if((argc==2) && !(strcmp(argv[1],"-l"))) {
		printk("\nCPUSTATE  TASK CPUNUM CPUID HARDCPU(HPA)\n");
#ifdef DUMP_MORE_STATE
		for(i=0;i<NR_CPUS;i++) {
			if (!cpu_online(i))
				continue;
			if (cpu_data[i].cpuid != NO_PROC_ID) {
				switch(cpu_data[i].state) {
					case STATE_RENDEZVOUS:
						printk("RENDEZVS ");
						break;
					case STATE_RUNNING:
						printk((current_pid(i)!=0) ? "RUNNING  " : "IDLING   ");
						break;
					case STATE_STOPPED:
						printk("STOPPED  ");
						break;
					case STATE_HALTED:
						printk("HALTED   ");
						break;
					default:
						printk("%08x?", cpu_data[i].state);
						break;
				}
				if(cpu_online(i)) {
					printk(" %4d",current_pid(i));
				}	
				printk(" %6d",cpu_number_map(i));
				printk(" %5d",i);
				printk(" 0x%lx\n",cpu_data[i].hpa);
			}	
		}
#else
		printk("\n%s  %4d      0     0 --------",
			(current->pid)?"RUNNING ": "IDLING  ",current->pid); 
#endif
	} else if ((argc==2) && !(strcmp(argv[1],"-s"))) { 
#ifdef DUMP_MORE_STATE
     		printk("\nCPUSTATE   CPUID\n");
		for (i=0;i<NR_CPUS;i++) {
			if (!cpu_online(i))
				continue;
			if (cpu_data[i].cpuid != NO_PROC_ID) {
				switch(cpu_data[i].state) {
					case STATE_RENDEZVOUS:
						printk("RENDEZVS");break;
					case STATE_RUNNING:
						printk((current_pid(i)!=0) ? "RUNNING " : "IDLING");
						break;
					case STATE_STOPPED:
						printk("STOPPED ");break;
					case STATE_HALTED:
						printk("HALTED  ");break;
					default:
				}
				printk("  %5d\n",i);
			}	
		}
#else
		printk("\n%s    CPU0",(current->pid==0)?"RUNNING ":"IDLING  "); 
#endif
	} else {
		printk("sys_cpus:Unknown request\n");
		return (-1);
	}
	return 0;
}
#endif /* ENTRY_SYS_CPUS */

#ifdef CONFIG_PROC_FS
int __init
setup_profiling_timer(unsigned int multiplier)
{
	return -EINVAL;
}
#endif