[deliverable/linux.git] / arch / parisc / kernel / smp.c

/*
** SMP Support
**
** Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
** Copyright (C) 1999 David Mosberger-Tang <davidm@hpl.hp.com>
** Copyright (C) 2001,2004 Grant Grundler <grundler@parisc-linux.org>
** 
** Lots of stuff stolen from arch/alpha/kernel/smp.c
** ...and then parisc stole from arch/ia64/kernel/smp.c. Thanks David! :^)
**
** Thanks to John Curry and Ullas Ponnadi. I learned a lot from their work.
** -grant (1/12/2001)
**
**	This program is free software; you can redistribute it and/or modify
**	it under the terms of the GNU General Public License as published by
**      the Free Software Foundation; either version 2 of the License, or
**      (at your option) any later version.
*/
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/slab.h>

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/smp.h>
#include <linux/kernel_stat.h>
#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/bitops.h>

#include <asm/system.h>
#include <asm/atomic.h>
#include <asm/current.h>
#include <asm/delay.h>
#include <asm/tlbflush.h>

#include <asm/io.h>
#include <asm/irq.h>		/* for CPU_IRQ_REGION and friends */
#include <asm/mmu_context.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/processor.h>
#include <asm/ptrace.h>
#include <asm/unistd.h>
#include <asm/cacheflush.h>

#undef DEBUG_SMP
#ifdef DEBUG_SMP
static int smp_debug_lvl = 0;
#define smp_debug(lvl, printargs...)		\
		if (lvl >= smp_debug_lvl)	\
			printk(printargs);
#else
#define smp_debug(lvl, ...)
#endif /* DEBUG_SMP */

DEFINE_SPINLOCK(smp_lock);

volatile struct task_struct *smp_init_current_idle_task;

static volatile int cpu_now_booting __read_mostly = 0;	/* track which CPU is booting */

static int parisc_max_cpus __read_mostly = 1;

/* online cpus are ones that we've managed to bring up completely
 * possible cpus are all valid cpu 
 * present cpus are all detected cpu
 *
 * On startup we bring up the "possible" cpus. Since we discover
 * CPUs later, we add them as hotplug, so the possible cpu mask is
 * empty in the beginning.
 */

cpumask_t cpu_online_map   __read_mostly = CPU_MASK_NONE;	/* Bitmap of online CPUs */
cpumask_t cpu_possible_map __read_mostly = CPU_MASK_ALL;	/* Bitmap of Present CPUs */

EXPORT_SYMBOL(cpu_online_map);
EXPORT_SYMBOL(cpu_possible_map);

DEFINE_PER_CPU(spinlock_t, ipi_lock) = SPIN_LOCK_UNLOCKED;

struct smp_call_struct {
	void (*func) (void *info);
	void *info;
	long wait;
	atomic_t unstarted_count;
	atomic_t unfinished_count;
};
static volatile struct smp_call_struct *smp_call_function_data;

enum ipi_message_type {
	IPI_NOP=0,
	IPI_RESCHEDULE=1,
	IPI_CALL_FUNC,
	IPI_CPU_START,
	IPI_CPU_STOP,
	IPI_CPU_TEST
};


/********** SMP inter processor interrupt and communication routines */

#undef PER_CPU_IRQ_REGION
#ifdef PER_CPU_IRQ_REGION
/* XXX REVISIT Ignore for now.
**    *May* need this "hook" to register IPI handler
**    once we have perCPU ExtIntr switch tables.
*/
static void
ipi_init(int cpuid)
{
#error verify IRQ_OFFSET(IPI_IRQ) is ipi_interrupt() in new IRQ region

	if(cpu_online(cpuid) )
	{
		switch_to_idle_task(current);
	}

	return;
}
#endif


/*
** Yoink this CPU from the runnable list... 
**
*/
static void
halt_processor(void) 
{
	/* REVISIT : redirect I/O Interrupts to another CPU? */
	/* REVISIT : does PM *know* this CPU isn't available? */
	cpu_clear(smp_processor_id(), cpu_online_map);
	local_irq_disable();
	for (;;)
		;
}


irqreturn_t
ipi_interrupt(int irq, void *dev_id) 
{
	int this_cpu = smp_processor_id();
	struct cpuinfo_parisc *p = &cpu_data[this_cpu];
	unsigned long ops;
	unsigned long flags;

	/* Count this now; we may make a call that never returns. */
	p->ipi_count++;

	mb();	/* Order interrupt and bit testing. */

	for (;;) {
		spinlock_t *lock = &per_cpu(ipi_lock, this_cpu);
		spin_lock_irqsave(lock, flags);
		ops = p->pending_ipi;
		p->pending_ipi = 0;
		spin_unlock_irqrestore(lock, flags);

		mb(); /* Order bit clearing and data access. */

		if (!ops)
		    break;

		while (ops) {
			unsigned long which = ffz(~ops);

			ops &= ~(1 << which);

			switch (which) {
			case IPI_NOP:
				smp_debug(100, KERN_DEBUG "CPU%d IPI_NOP\n", this_cpu);
				break;
				
			case IPI_RESCHEDULE:
				smp_debug(100, KERN_DEBUG "CPU%d IPI_RESCHEDULE\n", this_cpu);
				/*
				 * Reschedule callback.  Everything to be
				 * done is done by the interrupt return path.
				 */
				break;

			case IPI_CALL_FUNC:
				smp_debug(100, KERN_DEBUG "CPU%d IPI_CALL_FUNC\n", this_cpu);
				{
					volatile struct smp_call_struct *data;
					void (*func)(void *info);
					void *info;
					int wait;

					data = smp_call_function_data;
					func = data->func;
					info = data->info;
					wait = data->wait;

					mb();
					atomic_dec ((atomic_t *)&data->unstarted_count);

					/* At this point, *data can't
					 * be relied upon.
					 */

					(*func)(info);

					/* Notify the sending CPU that the
					 * task is done.
					 */
					mb();
					if (wait)
						atomic_dec ((atomic_t *)&data->unfinished_count);
				}
				break;

			case IPI_CPU_START:
				smp_debug(100, KERN_DEBUG "CPU%d IPI_CPU_START\n", this_cpu);
				break;

			case IPI_CPU_STOP:
				smp_debug(100, KERN_DEBUG "CPU%d IPI_CPU_STOP\n", this_cpu);
				halt_processor();
				break;

			case IPI_CPU_TEST:
				smp_debug(100, KERN_DEBUG "CPU%d is alive!\n", this_cpu);
				break;

			default:
				printk(KERN_CRIT "Unknown IPI num on CPU%d: %lu\n",
					this_cpu, which);
				return IRQ_NONE;
			} /* Switch */
		/* let in any pending interrupts */
		local_irq_enable();
		local_irq_disable();
		} /* while (ops) */
	}
	return IRQ_HANDLED;
}


static inline void
ipi_send(int cpu, enum ipi_message_type op)
{
	struct cpuinfo_parisc *p = &cpu_data[cpu];
	spinlock_t *lock = &per_cpu(ipi_lock, cpu);
	unsigned long flags;

	spin_lock_irqsave(lock, flags);
	p->pending_ipi |= 1 << op;
	gsc_writel(IPI_IRQ - CPU_IRQ_BASE, cpu_data[cpu].hpa);
	spin_unlock_irqrestore(lock, flags);
}


static inline void
send_IPI_single(int dest_cpu, enum ipi_message_type op)
{
	if (dest_cpu == NO_PROC_ID) {
		BUG();
		return;
	}

	ipi_send(dest_cpu, op);
}

static inline void
send_IPI_allbutself(enum ipi_message_type op)
{
	int i;
	
	for_each_online_cpu(i) {
		if (i != smp_processor_id())
			send_IPI_single(i, op);
	}
}


inline void 
smp_send_stop(void)	{ send_IPI_allbutself(IPI_CPU_STOP); }

static inline void
smp_send_start(void)	{ send_IPI_allbutself(IPI_CPU_START); }

void 
smp_send_reschedule(int cpu) { send_IPI_single(cpu, IPI_RESCHEDULE); }

void
smp_send_all_nop(void)
{
	send_IPI_allbutself(IPI_NOP);
}


/**
 * Run a function on all other CPUs.
 *  <func>	The function to run. This must be fast and non-blocking.
 *  <info>	An arbitrary pointer to pass to the function.
 *  <retry>	If true, keep retrying until ready.
 *  <wait>	If true, wait until function has completed on other CPUs.
 *  [RETURNS]   0 on success, else a negative status code.
 *
 * Does not return until remote CPUs are nearly ready to execute <func>
 * or have executed.
 */

int
smp_call_function (void (*func) (void *info), void *info, int retry, int wait)
{
	struct smp_call_struct data;
	unsigned long timeout;
	static DEFINE_SPINLOCK(lock);
	int retries = 0;

	if (num_online_cpus() < 2)
		return 0;

	/* Can deadlock when called with interrupts disabled */
	WARN_ON(irqs_disabled());

	/* can also deadlock if IPIs are disabled */
	WARN_ON((get_eiem() & (1UL<<(CPU_IRQ_MAX - IPI_IRQ))) == 0);

	
	data.func = func;
	data.info = info;
	data.wait = wait;
	atomic_set(&data.unstarted_count, num_online_cpus() - 1);
	atomic_set(&data.unfinished_count, num_online_cpus() - 1);

	if (retry) {
		spin_lock (&lock);
		while (smp_call_function_data != 0)
			barrier();
	}
	else {
		spin_lock (&lock);
		if (smp_call_function_data) {
			spin_unlock (&lock);
			return -EBUSY;
		}
	}

	smp_call_function_data = &data;
	spin_unlock (&lock);
	
	/*  Send a message to all other CPUs and wait for them to respond  */
	send_IPI_allbutself(IPI_CALL_FUNC);

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

	if (atomic_read (&data.unstarted_count) > 0) {
		printk(KERN_CRIT "SMP CALL FUNCTION TIMED OUT! (cpu=%d), try %d\n",
		      smp_processor_id(), ++retries);
		goto retry;
	}
	/* We either got one or timed out. Release the lock */

	mb();
	smp_call_function_data = NULL;

	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.
 */

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

/*
 * 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/processor.c */
	extern void init_IRQ(void);    /* arch/parisc/kernel/irq.c */
	extern void start_cpu_itimer(void); /* arch/parisc/kernel/time.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 IRQs are enabled or pending */
	start_cpu_itimer();
}


/*
 * 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)
{
	int slave_id = cpu_now_booting;
#if 0
	void *istack;
#endif

	smp_cpu_init(slave_id);
	preempt_disable();

#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(NULL);

	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 __cpuinit 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);

	task_thread_info(idle)->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."
	*/
	gsc_writel(TIMER_IRQ - CPU_IRQ_BASE, 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 */
	smp_debug(100, KERN_DEBUG "SMP: CPU:%d came alive after %ld _us\n",
		cpuid, timeout * 100);
	return 0;
}

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

	/* 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);
}


/*
** inventory.c:do_inventory() hasn't yet been run and thus we
** don't 'discover' the additional CPUs 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 __cpuinit __cpu_up(unsigned int cpu)
{
	if (cpu != 0 && cpu < parisc_max_cpus)
		smp_boot_one_cpu(cpu);

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

#ifdef CONFIG_PROC_FS
int __init
setup_profiling_timer(unsigned int multiplier)
{
	return -EINVAL;
}
#endif
Commit	Line	Data
1da177e4 LT	1	/*
	2	** SMP Support
	3	**
	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>
	7	**
	8	** Lots of stuff stolen from arch/alpha/kernel/smp.c
	9	** ...and then parisc stole from arch/ia64/kernel/smp.c. Thanks David! :^)
	10	**
7022672e	11	** Thanks to John Curry and Ullas Ponnadi. I learned a lot from their work.
1da177e4 LT	12	** -grant (1/12/2001)
	13	**
	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.
	18	*/
1da177e4 LT	19	#include <linux/types.h>
	20	#include <linux/spinlock.h>
	21	#include <linux/slab.h>
	22
	23	#include <linux/kernel.h>
	24	#include <linux/module.h>
	25	#include <linux/sched.h>
	26	#include <linux/init.h>
	27	#include <linux/interrupt.h>
	28	#include <linux/smp.h>
	29	#include <linux/kernel_stat.h>
	30	#include <linux/mm.h>
	31	#include <linux/delay.h>
	32	#include <linux/bitops.h>
	33
	34	#include <asm/system.h>
	35	#include <asm/atomic.h>
	36	#include <asm/current.h>
	37	#include <asm/delay.h>
1b2425e3	38	#include <asm/tlbflush.h>
1da177e4 LT	39
	40	#include <asm/io.h>
	41	#include <asm/irq.h> /* for CPU_IRQ_REGION and friends */
	42	#include <asm/mmu_context.h>
	43	#include <asm/page.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>
	50
5492a0f0 KM	51	#undef DEBUG_SMP
	52	#ifdef DEBUG_SMP
	53	static int smp_debug_lvl = 0;
	54	#define smp_debug(lvl, printargs...) \
	55	if (lvl >= smp_debug_lvl) \
	56	printk(printargs);
	57	#else
	58	#define smp_debug(lvl, ...)
	59	#endif /* DEBUG_SMP */
1da177e4 LT	60
	61	DEFINE_SPINLOCK(smp_lock);
	62
	63	volatile struct task_struct *smp_init_current_idle_task;
	64
8039de10	65	static volatile int cpu_now_booting __read_mostly = 0; /* track which CPU is booting */
1da177e4	66
8039de10	67	static int parisc_max_cpus __read_mostly = 1;
1da177e4 LT	68
	69	/* online cpus are ones that we've managed to bring up completely
	70	* possible cpus are all valid cpu
	71	* present cpus are all detected cpu
	72	*
	73	* On startup we bring up the "possible" cpus. Since we discover
	74	* CPUs later, we add them as hotplug, so the possible cpu mask is
	75	* empty in the beginning.
	76	*/
	77
8039de10 HD	78	cpumask_t cpu_online_map __read_mostly = CPU_MASK_NONE; /* Bitmap of online CPUs */
8039de10 HD	79	cpumask_t cpu_possible_map __read_mostly = CPU_MASK_ALL; /* Bitmap of Present CPUs */
1da177e4 LT	80
	81	EXPORT_SYMBOL(cpu_online_map);
	82	EXPORT_SYMBOL(cpu_possible_map);
	83
3c97b5e9	84	DEFINE_PER_CPU(spinlock_t, ipi_lock) = SPIN_LOCK_UNLOCKED;
1da177e4 LT	85
	86	struct smp_call_struct {
	87	void (func) (void info);
	88	void *info;
	89	long wait;
	90	atomic_t unstarted_count;
	91	atomic_t unfinished_count;
	92	};
	93	static volatile struct smp_call_struct *smp_call_function_data;
	94
	95	enum ipi_message_type {
	96	IPI_NOP=0,
	97	IPI_RESCHEDULE=1,
	98	IPI_CALL_FUNC,
	99	IPI_CPU_START,
	100	IPI_CPU_STOP,
	101	IPI_CPU_TEST
	102	};
	103
	104
	105	/********** SMP inter processor interrupt and communication routines */
	106
	107	#undef PER_CPU_IRQ_REGION
	108	#ifdef PER_CPU_IRQ_REGION
	109	/* XXX REVISIT Ignore for now.
	110	** May need this "hook" to register IPI handler
	111	** once we have perCPU ExtIntr switch tables.
	112	*/
	113	static void
	114	ipi_init(int cpuid)
	115	{
1da177e4 LT	116	#error verify IRQ_OFFSET(IPI_IRQ) is ipi_interrupt() in new IRQ region
	117
	118	if(cpu_online(cpuid) )
	119	{
	120	switch_to_idle_task(current);
	121	}
	122
	123	return;
	124	}
	125	#endif
	126
	127
	128	/*
	129	** Yoink this CPU from the runnable list...
	130	**
	131	*/
	132	static void
	133	halt_processor(void)
	134	{
1da177e4 LT	135	/* REVISIT : redirect I/O Interrupts to another CPU? */
	136	/* REVISIT : does PM know this CPU isn't available? */
	137	cpu_clear(smp_processor_id(), cpu_online_map);
	138	local_irq_disable();
	139	for (;;)
	140	;
1da177e4 LT	141	}
	142
	143
	144	irqreturn_t
c7753f18	145	ipi_interrupt(int irq, void *dev_id)
1da177e4 LT	146	{
	147	int this_cpu = smp_processor_id();
	148	struct cpuinfo_parisc *p = &cpu_data[this_cpu];
	149	unsigned long ops;
	150	unsigned long flags;
	151
	152	/* Count this now; we may make a call that never returns. */
	153	p->ipi_count++;
	154
	155	mb(); /* Order interrupt and bit testing. */
	156
	157	for (;;) {
3c97b5e9 KM	158	spinlock_t *lock = &per_cpu(ipi_lock, this_cpu);
3c97b5e9 KM	159	spin_lock_irqsave(lock, flags);
1da177e4 LT	160	ops = p->pending_ipi;
1da177e4 LT	161	p->pending_ipi = 0;
3c97b5e9	162	spin_unlock_irqrestore(lock, flags);
1da177e4 LT	163
	164	mb(); /* Order bit clearing and data access. */
	165
	166	if (!ops)
	167	break;
	168
	169	while (ops) {
	170	unsigned long which = ffz(~ops);
	171
d911aed8 JB	172	ops &= ~(1 << which);
d911aed8 JB	173
1da177e4	174	switch (which) {
d911aed8	175	case IPI_NOP:
5492a0f0	176	smp_debug(100, KERN_DEBUG "CPU%d IPI_NOP\n", this_cpu);
d911aed8 JB	177	break;
d911aed8 JB	178
1da177e4	179	case IPI_RESCHEDULE:
5492a0f0	180	smp_debug(100, KERN_DEBUG "CPU%d IPI_RESCHEDULE\n", this_cpu);
1da177e4 LT	181	/*
	182	* Reschedule callback. Everything to be
	183	* done is done by the interrupt return path.
	184	*/
	185	break;
	186
	187	case IPI_CALL_FUNC:
5492a0f0	188	smp_debug(100, KERN_DEBUG "CPU%d IPI_CALL_FUNC\n", this_cpu);
1da177e4 LT	189	{
	190	volatile struct smp_call_struct *data;
	191	void (func)(void info);
	192	void *info;
	193	int wait;
	194
	195	data = smp_call_function_data;
	196	func = data->func;
	197	info = data->info;
	198	wait = data->wait;
	199
	200	mb();
	201	atomic_dec ((atomic_t *)&data->unstarted_count);
	202
	203	/* At this point, *data can't
	204	* be relied upon.
	205	*/
	206
	207	(*func)(info);
	208
	209	/* Notify the sending CPU that the
	210	* task is done.
	211	*/
	212	mb();
	213	if (wait)
	214	atomic_dec ((atomic_t *)&data->unfinished_count);
	215	}
	216	break;
	217
	218	case IPI_CPU_START:
5492a0f0	219	smp_debug(100, KERN_DEBUG "CPU%d IPI_CPU_START\n", this_cpu);
1da177e4 LT	220	break;
	221
	222	case IPI_CPU_STOP:
5492a0f0	223	smp_debug(100, KERN_DEBUG "CPU%d IPI_CPU_STOP\n", this_cpu);
1da177e4	224	halt_processor();
1da177e4 LT	225	break;
	226
	227	case IPI_CPU_TEST:
5492a0f0	228	smp_debug(100, KERN_DEBUG "CPU%d is alive!\n", this_cpu);
1da177e4 LT	229	break;
	230
	231	default:
	232	printk(KERN_CRIT "Unknown IPI num on CPU%d: %lu\n",
	233	this_cpu, which);
1da177e4 LT	234	return IRQ_NONE;
1da177e4 LT	235	} /* Switch */
7085689e JB	236	/* let in any pending interrupts */
	237	local_irq_enable();
	238	local_irq_disable();
1da177e4 LT	239	} /* while (ops) */
	240	}
	241	return IRQ_HANDLED;
	242	}
	243
	244
	245	static inline void
	246	ipi_send(int cpu, enum ipi_message_type op)
	247	{
	248	struct cpuinfo_parisc *p = &cpu_data[cpu];
3c97b5e9	249	spinlock_t *lock = &per_cpu(ipi_lock, cpu);
1da177e4 LT	250	unsigned long flags;
1da177e4 LT	251
3c97b5e9	252	spin_lock_irqsave(lock, flags);
1da177e4 LT	253	p->pending_ipi \|= 1 << op;
1da177e4 LT	254	gsc_writel(IPI_IRQ - CPU_IRQ_BASE, cpu_data[cpu].hpa);
3c97b5e9	255	spin_unlock_irqrestore(lock, flags);
1da177e4 LT	256	}
	257
	258
	259	static inline void
	260	send_IPI_single(int dest_cpu, enum ipi_message_type op)
	261	{
	262	if (dest_cpu == NO_PROC_ID) {
	263	BUG();
	264	return;
	265	}
	266
	267	ipi_send(dest_cpu, op);
	268	}
	269
	270	static inline void
	271	send_IPI_allbutself(enum ipi_message_type op)
	272	{
	273	int i;
	274
394e3902 AM	275	for_each_online_cpu(i) {
394e3902 AM	276	if (i != smp_processor_id())
1da177e4 LT	277	send_IPI_single(i, op);
	278	}
	279	}
	280
	281
	282	inline void
	283	smp_send_stop(void) { send_IPI_allbutself(IPI_CPU_STOP); }
	284
	285	static inline void
	286	smp_send_start(void) { send_IPI_allbutself(IPI_CPU_START); }
	287
	288	void
	289	smp_send_reschedule(int cpu) { send_IPI_single(cpu, IPI_RESCHEDULE); }
	290
d911aed8 JB	291	void
	292	smp_send_all_nop(void)
	293	{
	294	send_IPI_allbutself(IPI_NOP);
	295	}
	296
1da177e4 LT	297
	298	/**
	299	* Run a function on all other CPUs.
	300	* <func> The function to run. This must be fast and non-blocking.
	301	* <info> An arbitrary pointer to pass to the function.
	302	* <retry> If true, keep retrying until ready.
	303	* <wait> If true, wait until function has completed on other CPUs.
	304	* [RETURNS] 0 on success, else a negative status code.
	305	*
	306	* Does not return until remote CPUs are nearly ready to execute <func>
	307	* or have executed.
	308	*/
	309
	310	int
	311	smp_call_function (void (func) (void info), void *info, int retry, int wait)
	312	{
	313	struct smp_call_struct data;
	314	unsigned long timeout;
	315	static DEFINE_SPINLOCK(lock);
	316	int retries = 0;
	317
	318	if (num_online_cpus() < 2)
	319	return 0;
	320
	321	/* Can deadlock when called with interrupts disabled */
	322	WARN_ON(irqs_disabled());
9a8b4584 JB	323
	324	/* can also deadlock if IPIs are disabled */
	325	WARN_ON((get_eiem() & (1UL<<(CPU_IRQ_MAX - IPI_IRQ))) == 0);
	326
1da177e4 LT	327
	328	data.func = func;
	329	data.info = info;
	330	data.wait = wait;
	331	atomic_set(&data.unstarted_count, num_online_cpus() - 1);
	332	atomic_set(&data.unfinished_count, num_online_cpus() - 1);
	333
	334	if (retry) {
	335	spin_lock (&lock);
	336	while (smp_call_function_data != 0)
	337	barrier();
	338	}
	339	else {
	340	spin_lock (&lock);
	341	if (smp_call_function_data) {
	342	spin_unlock (&lock);
	343	return -EBUSY;
	344	}
	345	}
	346
	347	smp_call_function_data = &data;
	348	spin_unlock (&lock);
	349
	350	/* Send a message to all other CPUs and wait for them to respond */
	351	send_IPI_allbutself(IPI_CALL_FUNC);
	352
	353	retry:
	354	/* Wait for response */
	355	timeout = jiffies + HZ;
	356	while ( (atomic_read (&data.unstarted_count) > 0) &&
	357	time_before (jiffies, timeout) )
	358	barrier ();
	359
	360	if (atomic_read (&data.unstarted_count) > 0) {
	361	printk(KERN_CRIT "SMP CALL FUNCTION TIMED OUT! (cpu=%d), try %d\n",
	362	smp_processor_id(), ++retries);
	363	goto retry;
	364	}
	365	/* We either got one or timed out. Release the lock */
	366
	367	mb();
	368	smp_call_function_data = NULL;
	369
	370	while (wait && atomic_read (&data.unfinished_count) > 0)
	371	barrier ();
	372
	373	return 0;
	374	}
	375
	376	EXPORT_SYMBOL(smp_call_function);
	377
	378	/*
	379	* Flush all other CPU's tlb and then mine. Do this with on_each_cpu()
	380	* as we want to ensure all TLB's flushed before proceeding.
	381	*/
	382
1da177e4 LT	383	void
	384	smp_flush_tlb_all(void)
	385	{
1b2425e3	386	on_each_cpu(flush_tlb_all_local, NULL, 1, 1);
1da177e4 LT	387	}
1da177e4 LT	388
1da177e4 LT	389	/*
	390	* Called by secondaries to update state and initialize CPU registers.
	391	*/
	392	static void __init
	393	smp_cpu_init(int cpunum)
	394	{
56f335c8	395	extern int init_per_cpu(int); /* arch/parisc/kernel/processor.c */
1da177e4	396	extern void init_IRQ(void); /* arch/parisc/kernel/irq.c */
56f335c8	397	extern void start_cpu_itimer(void); /* arch/parisc/kernel/time.c */
1da177e4 LT	398
	399	/* Set modes and Enable floating point coprocessor */
	400	(void) init_per_cpu(cpunum);
	401
	402	disable_sr_hashing();
	403
	404	mb();
	405
	406	/* Well, support 2.4 linux scheme as well. */
	407	if (cpu_test_and_set(cpunum, cpu_online_map))
	408	{
	409	extern void machine_halt(void); /* arch/parisc.../process.c */
	410
	411	printk(KERN_CRIT "CPU#%d already initialized!\n", cpunum);
	412	machine_halt();
	413	}
	414
	415	/* Initialise the idle task for this CPU */
	416	atomic_inc(&init_mm.mm_count);
	417	current->active_mm = &init_mm;
	418	if(current->mm)
	419	BUG();
	420	enter_lazy_tlb(&init_mm, current);
	421
7022672e	422	init_IRQ(); /* make sure no IRQs are enabled or pending */
56f335c8	423	start_cpu_itimer();
1da177e4 LT	424	}
	425
	426
	427	/*
	428	* Slaves start using C here. Indirectly called from smp_slave_stext.
	429	* Do what start_kernel() and main() do for boot strap processor (aka monarch)
	430	*/
	431	void __init smp_callin(void)
	432	{
	433	int slave_id = cpu_now_booting;
	434	#if 0
	435	void *istack;
	436	#endif
	437
	438	smp_cpu_init(slave_id);
5bfb5d69	439	preempt_disable();
1da177e4 LT	440
	441	#if 0 /* NOT WORKING YET - see entry.S */
	442	istack = (void *)__get_free_pages(GFP_KERNEL,ISTACK_ORDER);
	443	if (istack == NULL) {
	444	printk(KERN_CRIT "Failed to allocate interrupt stack for cpu %d\n",slave_id);
	445	BUG();
	446	}
	447	mtctl(istack,31);
	448	#endif
	449
	450	flush_cache_all_local(); /* start with known state */
1b2425e3	451	flush_tlb_all_local(NULL);
1da177e4 LT	452
	453	local_irq_enable(); /* Interrupts have been off until now */
	454
	455	cpu_idle(); /* Wait for timer to schedule some work */
	456
	457	/* NOTREACHED */
	458	panic("smp_callin() AAAAaaaaahhhh....\n");
	459	}
	460
	461	/*
	462	* Bring one cpu online.
	463	*/
8dff980f	464	int __cpuinit smp_boot_one_cpu(int cpuid)
1da177e4 LT	465	{
	466	struct task_struct *idle;
	467	long timeout;
	468
	469	/*
	470	* Create an idle task for this CPU. Note the address wed* give
	471	* to kernel_thread is irrelevant -- it's going to start
	472	* where OS_BOOT_RENDEVZ vector in SAL says to start. But
	473	* this gets all the other task-y sort of data structures set
	474	* up like we wish. We need to pull the just created idle task
	475	* off the run queue and stuff it into the init_tasks[] array.
	476	* Sheesh . . .
	477	*/
	478
	479	idle = fork_idle(cpuid);
	480	if (IS_ERR(idle))
	481	panic("SMP: fork failed for CPU:%d", cpuid);
	482
40f1f0de	483	task_thread_info(idle)->cpu = cpuid;
1da177e4 LT	484
	485	/* Let _start know what logical CPU we're booting
	486	** (offset into init_tasks[],cpu_data[])
	487	*/
	488	cpu_now_booting = cpuid;
	489
	490	/*
	491	** boot strap code needs to know the task address since
	492	** it also contains the process stack.
	493	*/
	494	smp_init_current_idle_task = idle ;
	495	mb();
	496
	497	printk("Releasing cpu %d now, hpa=%lx\n", cpuid, cpu_data[cpuid].hpa);
	498
	499	/*
	500	** This gets PDC to release the CPU from a very tight loop.
	501	**
	502	** From the PA-RISC 2.0 Firmware Architecture Reference Specification:
	503	** "The MEM_RENDEZ vector specifies the location of OS_RENDEZ which
	504	** is executed after receiving the rendezvous signal (an interrupt to
	505	** EIR{0}). MEM_RENDEZ is valid only when it is nonzero and the
	506	** contents of memory are valid."
	507	*/
	508	gsc_writel(TIMER_IRQ - CPU_IRQ_BASE, cpu_data[cpuid].hpa);
	509	mb();
	510
	511	/*
	512	* OK, wait a bit for that CPU to finish staggering about.
	513	* Slave will set a bit when it reaches smp_cpu_init().
	514	* Once the "monarch CPU" sees the bit change, it can move on.
	515	*/
	516	for (timeout = 0; timeout < 10000; timeout++) {
	517	if(cpu_online(cpuid)) {
	518	/* Which implies Slave has started up */
	519	cpu_now_booting = 0;
	520	smp_init_current_idle_task = NULL;
	521	goto alive ;
	522	}
	523	udelay(100);
	524	barrier();
	525	}
	526
	527	put_task_struct(idle);
	528	idle = NULL;
	529
	530	printk(KERN_CRIT "SMP: CPU:%d is stuck.\n", cpuid);
	531	return -1;
	532
	533	alive:
	534	/* Remember the Slave data */
5492a0f0	535	smp_debug(100, KERN_DEBUG "SMP: CPU:%d came alive after %ld _us\n",
1da177e4	536	cpuid, timeout * 100);
1da177e4 LT	537	return 0;
	538	}
	539
	540	void __devinit smp_prepare_boot_cpu(void)
	541	{
	542	int bootstrap_processor=cpu_data[0].cpuid; /* CPU ID of BSP */
	543
1da177e4 LT	544	/* Setup BSP mappings */
	545	printk("SMP: bootstrap CPU ID is %d\n",bootstrap_processor);
	546
	547	cpu_set(bootstrap_processor, cpu_online_map);
	548	cpu_set(bootstrap_processor, cpu_present_map);
	549	}
	550
	551
	552
	553	/*
	554	** inventory.c:do_inventory() hasn't yet been run and thus we
7022672e	555	** don't 'discover' the additional CPUs until later.
1da177e4 LT	556	*/
	557	void __init smp_prepare_cpus(unsigned int max_cpus)
	558	{
	559	cpus_clear(cpu_present_map);
	560	cpu_set(0, cpu_present_map);
	561
	562	parisc_max_cpus = max_cpus;
	563	if (!max_cpus)
	564	printk(KERN_INFO "SMP mode deactivated.\n");
	565	}
	566
	567
	568	void smp_cpus_done(unsigned int cpu_max)
	569	{
	570	return;
	571	}
	572
	573
b282b6f8	574	int __cpuinit __cpu_up(unsigned int cpu)
1da177e4 LT	575	{
	576	if (cpu != 0 && cpu < parisc_max_cpus)
	577	smp_boot_one_cpu(cpu);
	578
	579	return cpu_online(cpu) ? 0 : -ENOSYS;
	580	}
	581
1da177e4 LT	582	#ifdef CONFIG_PROC_FS
	583	int __init
	584	setup_profiling_timer(unsigned int multiplier)
	585	{
	586	return -EINVAL;
	587	}
	588	#endif