[mirror_ubuntu-jammy-kernel.git] / arch / parisc / kernel / smp.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
** 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)
**
*/
#include <linux/types.h>
#include <linux/spinlock.h>

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

#include <linux/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/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, ...)	do { } while(0)
#endif /* DEBUG_SMP */

volatile struct task_struct *smp_init_current_idle_task;

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

static int parisc_max_cpus = 1;

static DEFINE_PER_CPU(spinlock_t, ipi_lock);

enum ipi_message_type {
	IPI_NOP=0,
	IPI_RESCHEDULE=1,
	IPI_CALL_FUNC,
	IPI_CPU_START,
	IPI_CPU_STOP,
	IPI_CPU_TEST,
#ifdef CONFIG_KGDB
	IPI_ENTER_KGDB,
#endif
};


/********** 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? */
	set_cpu_online(smp_processor_id(), false);
	local_irq_disable();
	__pdc_cpu_rendezvous();
	for (;;)
		;
}


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

	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);
				inc_irq_stat(irq_resched_count);
				scheduler_ipi();
				break;

			case IPI_CALL_FUNC:
				smp_debug(100, KERN_DEBUG "CPU%d IPI_CALL_FUNC\n", this_cpu);
				inc_irq_stat(irq_call_count);
				generic_smp_call_function_interrupt();
				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;
#ifdef CONFIG_KGDB
			case IPI_ENTER_KGDB:
				smp_debug(100, KERN_DEBUG "CPU%d ENTER_KGDB\n", this_cpu);
				kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
				break;
#endif
			default:
				printk(KERN_CRIT "Unknown IPI num on CPU%d: %lu\n",
					this_cpu, which);
				return IRQ_NONE;
			} /* Switch */

			/* before doing more, let in any pending interrupts */
			if (ops) {
				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 = &per_cpu(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, p->hpa);
	spin_unlock_irqrestore(lock, flags);
}

static void
send_IPI_mask(const struct cpumask *mask, enum ipi_message_type op)
{
	int cpu;

	for_each_cpu(cpu, mask)
		ipi_send(cpu, op);
}

static inline void
send_IPI_single(int dest_cpu, enum ipi_message_type op)
{
	BUG_ON(dest_cpu == NO_PROC_ID);

	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);
	}
}

#ifdef CONFIG_KGDB
void kgdb_roundup_cpus(void)
{
	send_IPI_allbutself(IPI_ENTER_KGDB);
}
#endif

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

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

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

void arch_send_call_function_ipi_mask(const struct cpumask *mask)
{
	send_IPI_mask(mask, IPI_CALL_FUNC);
}

void arch_send_call_function_single_ipi(int cpu)
{
	send_IPI_single(cpu, IPI_CALL_FUNC);
}

/*
 * Called by secondaries to update state and initialize CPU registers.
 */
static void __init
smp_cpu_init(int cpunum)
{
	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 */
	init_per_cpu(cpunum);

	disable_sr_hashing();

	mb();

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

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

	notify_cpu_starting(cpunum);

	set_cpu_online(cpunum, true);

	/* Initialise the idle task for this CPU */
	mmgrab(&init_mm);
	current->active_mm = &init_mm;
	BUG_ON(current->mm);
	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(unsigned long pdce_proc)
{
	int slave_id = cpu_now_booting;

#ifdef CONFIG_64BIT
	WARN_ON(((unsigned long)(PAGE0->mem_pdc_hi) << 32
			| PAGE0->mem_pdc) != pdce_proc);
#endif

	smp_cpu_init(slave_id);

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

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

	cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);

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

/*
 * Bring one cpu online.
 */
int smp_boot_one_cpu(int cpuid, struct task_struct *idle)
{
	const struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpuid);
	long timeout;

	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(KERN_INFO "Releasing cpu %d now, hpa=%lx\n", cpuid, p->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, p->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();
	}
	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 __init smp_prepare_boot_cpu(void)
{
	int bootstrap_processor = per_cpu(cpu_data, 0).cpuid;

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

	set_cpu_online(bootstrap_processor, true);
	set_cpu_present(bootstrap_processor, true);
}


/*
** 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)
{
	int cpu;

	for_each_possible_cpu(cpu)
		spin_lock_init(&per_cpu(ipi_lock, cpu));

	init_cpu_present(cpumask_of(0));

	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 __cpu_up(unsigned int cpu, struct task_struct *tidle)
{
	if (cpu != 0 && cpu < parisc_max_cpus && smp_boot_one_cpu(cpu, tidle))
		return -ENOSYS;

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

#ifdef CONFIG_PROC_FS
int setup_profiling_timer(unsigned int multiplier)
{
	return -EINVAL;
}
#endif
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
1da177e4 LT	2	/*
	3	** SMP Support
	4	**
	5	** Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
	6	** Copyright (C) 1999 David Mosberger-Tang <davidm@hpl.hp.com>
	7	** Copyright (C) 2001,2004 Grant Grundler <grundler@parisc-linux.org>
	8	**
	9	** Lots of stuff stolen from arch/alpha/kernel/smp.c
	10	** ...and then parisc stole from arch/ia64/kernel/smp.c. Thanks David! :^)
	11	**
7022672e	12	** Thanks to John Curry and Ullas Ponnadi. I learned a lot from their work.
1da177e4 LT	13	** -grant (1/12/2001)
1da177e4 LT	14	**
1da177e4	15	*/
1da177e4 LT	16	#include <linux/types.h>
1da177e4 LT	17	#include <linux/spinlock.h>
1da177e4 LT	18
	19	#include <linux/kernel.h>
	20	#include <linux/module.h>
68e21be2	21	#include <linux/sched/mm.h>
1da177e4 LT	22	#include <linux/init.h>
	23	#include <linux/interrupt.h>
	24	#include <linux/smp.h>
	25	#include <linux/kernel_stat.h>
	26	#include <linux/mm.h>
4e950f6f	27	#include <linux/err.h>
1da177e4 LT	28	#include <linux/delay.h>
1da177e4 LT	29	#include <linux/bitops.h>
d75f054a	30	#include <linux/ftrace.h>
ec2e0f98	31	#include <linux/cpu.h>
1251b34e	32	#include <linux/kgdb.h>
1da177e4	33
60063497	34	#include <linux/atomic.h>
1da177e4 LT	35	#include <asm/current.h>
1da177e4 LT	36	#include <asm/delay.h>
1b2425e3	37	#include <asm/tlbflush.h>
1da177e4 LT	38
	39	#include <asm/io.h>
	40	#include <asm/irq.h> /* for CPU_IRQ_REGION and friends */
	41	#include <asm/mmu_context.h>
	42	#include <asm/page.h>
1da177e4 LT	43	#include <asm/processor.h>
	44	#include <asm/ptrace.h>
	45	#include <asm/unistd.h>
	46	#include <asm/cacheflush.h>
	47
5492a0f0 KM	48	#undef DEBUG_SMP
	49	#ifdef DEBUG_SMP
	50	static int smp_debug_lvl = 0;
	51	#define smp_debug(lvl, printargs...) \
	52	if (lvl >= smp_debug_lvl) \
	53	printk(printargs);
	54	#else
ef017beb	55	#define smp_debug(lvl, ...) do { } while(0)
5492a0f0	56	#endif /* DEBUG_SMP */
1da177e4	57
1da177e4 LT	58	volatile struct task_struct *smp_init_current_idle_task;
1da177e4 LT	59
ef017beb	60	/* track which CPU is booting */
60ffef06	61	static volatile int cpu_now_booting;
1da177e4	62
60ffef06	63	static int parisc_max_cpus = 1;
1da177e4	64
6ad6c424	65	static DEFINE_PER_CPU(spinlock_t, ipi_lock);
1da177e4	66
1da177e4 LT	67	enum ipi_message_type {
	68	IPI_NOP=0,
	69	IPI_RESCHEDULE=1,
	70	IPI_CALL_FUNC,
	71	IPI_CPU_START,
	72	IPI_CPU_STOP,
1251b34e SS	73	IPI_CPU_TEST,
	74	#ifdef CONFIG_KGDB
	75	IPI_ENTER_KGDB,
	76	#endif
1da177e4 LT	77	};
	78
	79
	80	/********** SMP inter processor interrupt and communication routines */
	81
	82	#undef PER_CPU_IRQ_REGION
	83	#ifdef PER_CPU_IRQ_REGION
	84	/* XXX REVISIT Ignore for now.
	85	** May need this "hook" to register IPI handler
	86	** once we have perCPU ExtIntr switch tables.
	87	*/
	88	static void
	89	ipi_init(int cpuid)
	90	{
1da177e4 LT	91	#error verify IRQ_OFFSET(IPI_IRQ) is ipi_interrupt() in new IRQ region
	92
	93	if(cpu_online(cpuid) )
	94	{
	95	switch_to_idle_task(current);
	96	}
	97
	98	return;
	99	}
	100	#endif
	101
	102
	103	/*
	104	** Yoink this CPU from the runnable list...
	105	**
	106	*/
	107	static void
	108	halt_processor(void)
	109	{
1da177e4 LT	110	/* REVISIT : redirect I/O Interrupts to another CPU? */
1da177e4 LT	111	/* REVISIT : does PM know this CPU isn't available? */
9bc181d8	112	set_cpu_online(smp_processor_id(), false);
1da177e4	113	local_irq_disable();
507efd63	114	__pdc_cpu_rendezvous();
1da177e4 LT	115	for (;;)
1da177e4 LT	116	;
1da177e4 LT	117	}
	118
	119
d75f054a	120	irqreturn_t __irq_entry
c7753f18	121	ipi_interrupt(int irq, void *dev_id)
1da177e4 LT	122	{
1da177e4 LT	123	int this_cpu = smp_processor_id();
ef017beb	124	struct cpuinfo_parisc *p = &per_cpu(cpu_data, this_cpu);
1da177e4 LT	125	unsigned long ops;
	126	unsigned long flags;
	127
1da177e4	128	for (;;) {
3c97b5e9 KM	129	spinlock_t *lock = &per_cpu(ipi_lock, this_cpu);
3c97b5e9 KM	130	spin_lock_irqsave(lock, flags);
1da177e4 LT	131	ops = p->pending_ipi;
1da177e4 LT	132	p->pending_ipi = 0;
3c97b5e9	133	spin_unlock_irqrestore(lock, flags);
1da177e4 LT	134
	135	mb(); /* Order bit clearing and data access. */
	136
	137	if (!ops)
	138	break;
	139
	140	while (ops) {
	141	unsigned long which = ffz(~ops);
	142
d911aed8 JB	143	ops &= ~(1 << which);
d911aed8 JB	144
1da177e4	145	switch (which) {
d911aed8	146	case IPI_NOP:
5492a0f0	147	smp_debug(100, KERN_DEBUG "CPU%d IPI_NOP\n", this_cpu);
d911aed8 JB	148	break;
d911aed8 JB	149
1da177e4	150	case IPI_RESCHEDULE:
5492a0f0	151	smp_debug(100, KERN_DEBUG "CPU%d IPI_RESCHEDULE\n", this_cpu);
cd85d551	152	inc_irq_stat(irq_resched_count);
184748cc	153	scheduler_ipi();
1da177e4 LT	154	break;
	155
	156	case IPI_CALL_FUNC:
5492a0f0	157	smp_debug(100, KERN_DEBUG "CPU%d IPI_CALL_FUNC\n", this_cpu);
b102f29b	158	inc_irq_stat(irq_call_count);
dbcf4787 JA	159	generic_smp_call_function_interrupt();
	160	break;
	161
1da177e4	162	case IPI_CPU_START:
5492a0f0	163	smp_debug(100, KERN_DEBUG "CPU%d IPI_CPU_START\n", this_cpu);
1da177e4 LT	164	break;
	165
	166	case IPI_CPU_STOP:
5492a0f0	167	smp_debug(100, KERN_DEBUG "CPU%d IPI_CPU_STOP\n", this_cpu);
1da177e4	168	halt_processor();
1da177e4 LT	169	break;
	170
	171	case IPI_CPU_TEST:
5492a0f0	172	smp_debug(100, KERN_DEBUG "CPU%d is alive!\n", this_cpu);
1da177e4	173	break;
1251b34e SS	174	#ifdef CONFIG_KGDB
	175	case IPI_ENTER_KGDB:
	176	smp_debug(100, KERN_DEBUG "CPU%d ENTER_KGDB\n", this_cpu);
	177	kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
	178	break;
	179	#endif
1da177e4 LT	180	default:
	181	printk(KERN_CRIT "Unknown IPI num on CPU%d: %lu\n",
	182	this_cpu, which);
1da177e4 LT	183	return IRQ_NONE;
1da177e4 LT	184	} /* Switch */
f4d0d40c HD	185
	186	/* before doing more, let in any pending interrupts */
	187	if (ops) {
	188	local_irq_enable();
	189	local_irq_disable();
	190	}
1da177e4 LT	191	} /* while (ops) */
	192	}
	193	return IRQ_HANDLED;
	194	}
	195
	196
	197	static inline void
	198	ipi_send(int cpu, enum ipi_message_type op)
	199	{
ef017beb	200	struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpu);
3c97b5e9	201	spinlock_t *lock = &per_cpu(ipi_lock, cpu);
1da177e4 LT	202	unsigned long flags;
1da177e4 LT	203
3c97b5e9	204	spin_lock_irqsave(lock, flags);
1da177e4	205	p->pending_ipi \|= 1 << op;
ef017beb	206	gsc_writel(IPI_IRQ - CPU_IRQ_BASE, p->hpa);
3c97b5e9	207	spin_unlock_irqrestore(lock, flags);
1da177e4 LT	208	}
1da177e4 LT	209
dbcf4787	210	static void
91887a36	211	send_IPI_mask(const struct cpumask *mask, enum ipi_message_type op)
dbcf4787 JA	212	{
	213	int cpu;
	214
91887a36	215	for_each_cpu(cpu, mask)
dbcf4787 JA	216	ipi_send(cpu, op);
dbcf4787 JA	217	}
1da177e4 LT	218
	219	static inline void
	220	send_IPI_single(int dest_cpu, enum ipi_message_type op)
	221	{
7f2347a4	222	BUG_ON(dest_cpu == NO_PROC_ID);
1da177e4 LT	223
	224	ipi_send(dest_cpu, op);
	225	}
	226
	227	static inline void
	228	send_IPI_allbutself(enum ipi_message_type op)
	229	{
	230	int i;
	231
394e3902 AM	232	for_each_online_cpu(i) {
394e3902 AM	233	if (i != smp_processor_id())
1da177e4 LT	234	send_IPI_single(i, op);
	235	}
	236	}
	237
1251b34e SS	238	#ifdef CONFIG_KGDB
	239	void kgdb_roundup_cpus(void)
	240	{
	241	send_IPI_allbutself(IPI_ENTER_KGDB);
	242	}
	243	#endif
1da177e4 LT	244
	245	inline void
	246	smp_send_stop(void) { send_IPI_allbutself(IPI_CPU_STOP); }
	247
1da177e4 LT	248	void
	249	smp_send_reschedule(int cpu) { send_IPI_single(cpu, IPI_RESCHEDULE); }
	250
d911aed8 JB	251	void
	252	smp_send_all_nop(void)
	253	{
	254	send_IPI_allbutself(IPI_NOP);
	255	}
	256
91887a36	257	void arch_send_call_function_ipi_mask(const struct cpumask *mask)
1da177e4	258	{
dbcf4787	259	send_IPI_mask(mask, IPI_CALL_FUNC);
1da177e4 LT	260	}
1da177e4 LT	261
dbcf4787 JA	262	void arch_send_call_function_single_ipi(int cpu)
dbcf4787 JA	263	{
528d8eb2	264	send_IPI_single(cpu, IPI_CALL_FUNC);
dbcf4787	265	}
1da177e4	266
1da177e4 LT	267	/*
	268	* Called by secondaries to update state and initialize CPU registers.
	269	*/
	270	static void __init
	271	smp_cpu_init(int cpunum)
	272	{
1da177e4	273	extern void init_IRQ(void); /* arch/parisc/kernel/irq.c */
56f335c8	274	extern void start_cpu_itimer(void); /* arch/parisc/kernel/time.c */
1da177e4 LT	275
1da177e4 LT	276	/* Set modes and Enable floating point coprocessor */
a7e6601f	277	init_per_cpu(cpunum);
1da177e4 LT	278
	279	disable_sr_hashing();
	280
	281	mb();
	282
	283	/* Well, support 2.4 linux scheme as well. */
7ec6118c	284	if (cpu_online(cpunum)) {
1da177e4 LT	285	extern void machine_halt(void); /* arch/parisc.../process.c */
	286
	287	printk(KERN_CRIT "CPU#%d already initialized!\n", cpunum);
	288	machine_halt();
ec2e0f98 SB	289	}
	290
	291	notify_cpu_starting(cpunum);
	292
9bc181d8	293	set_cpu_online(cpunum, true);
1da177e4 LT	294
1da177e4 LT	295	/* Initialise the idle task for this CPU */
f1f10076	296	mmgrab(&init_mm);
1da177e4	297	current->active_mm = &init_mm;
7f2347a4	298	BUG_ON(current->mm);
1da177e4 LT	299	enter_lazy_tlb(&init_mm, current);
1da177e4 LT	300
7022672e	301	init_IRQ(); /* make sure no IRQs are enabled or pending */
56f335c8	302	start_cpu_itimer();
1da177e4 LT	303	}
	304
	305
	306	/*
	307	* Slaves start using C here. Indirectly called from smp_slave_stext.
	308	* Do what start_kernel() and main() do for boot strap processor (aka monarch)
	309	*/
0ed1fe4a	310	void __init smp_callin(unsigned long pdce_proc)
1da177e4 LT	311	{
1da177e4 LT	312	int slave_id = cpu_now_booting;
1da177e4	313
0ed1fe4a HD	314	#ifdef CONFIG_64BIT
	315	WARN_ON(((unsigned long)(PAGE0->mem_pdc_hi) << 32
	316	\| PAGE0->mem_pdc) != pdce_proc);
	317	#endif
	318
1da177e4 LT	319	smp_cpu_init(slave_id);
1da177e4 LT	320
1da177e4	321	flush_cache_all_local(); /* start with known state */
1b2425e3	322	flush_tlb_all_local(NULL);
1da177e4 LT	323
	324	local_irq_enable(); /* Interrupts have been off until now */
	325
fc6d73d6	326	cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
1da177e4 LT	327
	328	/* NOTREACHED */
	329	panic("smp_callin() AAAAaaaaahhhh....\n");
	330	}
	331
	332	/*
	333	* Bring one cpu online.
	334	*/
60ffef06	335	int smp_boot_one_cpu(int cpuid, struct task_struct *idle)
1da177e4	336	{
ef017beb	337	const struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpuid);
1da177e4 LT	338	long timeout;
1da177e4 LT	339
40f1f0de	340	task_thread_info(idle)->cpu = cpuid;
1da177e4 LT	341
	342	/* Let _start know what logical CPU we're booting
	343	** (offset into init_tasks[],cpu_data[])
	344	*/
	345	cpu_now_booting = cpuid;
	346
	347	/*
	348	** boot strap code needs to know the task address since
	349	** it also contains the process stack.
	350	*/
	351	smp_init_current_idle_task = idle ;
	352	mb();
	353
ef017beb	354	printk(KERN_INFO "Releasing cpu %d now, hpa=%lx\n", cpuid, p->hpa);
1da177e4 LT	355
	356	/*
	357	** This gets PDC to release the CPU from a very tight loop.
	358	**
	359	** From the PA-RISC 2.0 Firmware Architecture Reference Specification:
	360	** "The MEM_RENDEZ vector specifies the location of OS_RENDEZ which
	361	** is executed after receiving the rendezvous signal (an interrupt to
	362	** EIR{0}). MEM_RENDEZ is valid only when it is nonzero and the
	363	** contents of memory are valid."
	364	*/
ef017beb	365	gsc_writel(TIMER_IRQ - CPU_IRQ_BASE, p->hpa);
1da177e4 LT	366	mb();
	367
	368	/*
	369	* OK, wait a bit for that CPU to finish staggering about.
	370	* Slave will set a bit when it reaches smp_cpu_init().
	371	* Once the "monarch CPU" sees the bit change, it can move on.
	372	*/
	373	for (timeout = 0; timeout < 10000; timeout++) {
	374	if(cpu_online(cpuid)) {
	375	/* Which implies Slave has started up */
	376	cpu_now_booting = 0;
	377	smp_init_current_idle_task = NULL;
	378	goto alive ;
	379	}
	380	udelay(100);
	381	barrier();
	382	}
1da177e4 LT	383	printk(KERN_CRIT "SMP: CPU:%d is stuck.\n", cpuid);
	384	return -1;
	385
	386	alive:
	387	/* Remember the Slave data */
5492a0f0	388	smp_debug(100, KERN_DEBUG "SMP: CPU:%d came alive after %ld _us\n",
1da177e4	389	cpuid, timeout * 100);
1da177e4 LT	390	return 0;
	391	}
	392
ef017beb	393	void __init smp_prepare_boot_cpu(void)
1da177e4	394	{
ef017beb	395	int bootstrap_processor = per_cpu(cpu_data, 0).cpuid;
1da177e4	396
1da177e4	397	/* Setup BSP mappings */
ef017beb	398	printk(KERN_INFO "SMP: bootstrap CPU ID is %d\n", bootstrap_processor);
1da177e4	399
9bc181d8 RR	400	set_cpu_online(bootstrap_processor, true);
9bc181d8 RR	401	set_cpu_present(bootstrap_processor, true);
1da177e4 LT	402	}
	403
	404
	405
	406	/*
	407	** inventory.c:do_inventory() hasn't yet been run and thus we
7022672e	408	** don't 'discover' the additional CPUs until later.
1da177e4 LT	409	*/
	410	void __init smp_prepare_cpus(unsigned int max_cpus)
	411	{
6ad6c424 TG	412	int cpu;
	413
	414	for_each_possible_cpu(cpu)
	415	spin_lock_init(&per_cpu(ipi_lock, cpu));
	416
9bc181d8	417	init_cpu_present(cpumask_of(0));
1da177e4 LT	418
	419	parisc_max_cpus = max_cpus;
	420	if (!max_cpus)
	421	printk(KERN_INFO "SMP mode deactivated.\n");
	422	}
	423
	424
	425	void smp_cpus_done(unsigned int cpu_max)
	426	{
	427	return;
	428	}
	429
	430
60ffef06	431	int __cpu_up(unsigned int cpu, struct task_struct *tidle)
1da177e4	432	{
5baf919d HD	433	if (cpu != 0 && cpu < parisc_max_cpus && smp_boot_one_cpu(cpu, tidle))
5baf919d HD	434	return -ENOSYS;
1da177e4 LT	435
	436	return cpu_online(cpu) ? 0 : -ENOSYS;
	437	}
	438
1da177e4	439	#ifdef CONFIG_PROC_FS
01f56832	440	int setup_profiling_timer(unsigned int multiplier)
1da177e4 LT	441	{
	442	return -EINVAL;
	443	}
	444	#endif