[deliverable/linux.git] / arch / ia64 / kernel / smp.c

/*
 * SMP Support
 *
 * Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
 * Copyright (C) 1999, 2001, 2003 David Mosberger-Tang <davidm@hpl.hp.com>
 *
 * Lots of stuff stolen from arch/alpha/kernel/smp.c
 *
 * 01/05/16 Rohit Seth <rohit.seth@intel.com>  IA64-SMP functions. Reorganized
 * the existing code (on the lines of x86 port).
 * 00/09/11 David Mosberger <davidm@hpl.hp.com> Do loops_per_jiffy
 * calibration on each CPU.
 * 00/08/23 Asit Mallick <asit.k.mallick@intel.com> fixed logical processor id
 * 00/03/31 Rohit Seth <rohit.seth@intel.com>	Fixes for Bootstrap Processor
 * & cpu_online_map now gets done here (instead of setup.c)
 * 99/10/05 davidm	Update to bring it in sync with new command-line processing
 *  scheme.
 * 10/13/00 Goutham Rao <goutham.rao@intel.com> Updated smp_call_function and
 *		smp_call_function_single to resend IPI on timeouts
 */
#include <linux/module.h>
#include <linux/kernel.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/cache.h>
#include <linux/delay.h>
#include <linux/efi.h>
#include <linux/bitops.h>

#include <asm/atomic.h>
#include <asm/current.h>
#include <asm/delay.h>
#include <asm/machvec.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/ptrace.h>
#include <asm/sal.h>
#include <asm/system.h>
#include <asm/tlbflush.h>
#include <asm/unistd.h>
#include <asm/mca.h>

/*
 * Structure and data for smp_call_function(). This is designed to minimise static memory
 * requirements. It also looks cleaner.
 */
static  __cacheline_aligned DEFINE_SPINLOCK(call_lock);

struct call_data_struct {
	void (*func) (void *info);
	void *info;
	long wait;
	atomic_t started;
	atomic_t finished;
};

static volatile struct call_data_struct *call_data;

#define IPI_CALL_FUNC		0
#define IPI_CPU_STOP		1

/* This needs to be cacheline aligned because it is written to by *other* CPUs.  */
static DEFINE_PER_CPU(u64, ipi_operation) ____cacheline_aligned;

extern void cpu_halt (void);

void
lock_ipi_calllock(void)
{
	spin_lock_irq(&call_lock);
}

void
unlock_ipi_calllock(void)
{
	spin_unlock_irq(&call_lock);
}

static void
stop_this_cpu (void)
{
	/*
	 * Remove this CPU:
	 */
	cpu_clear(smp_processor_id(), cpu_online_map);
	max_xtp();
	local_irq_disable();
	cpu_halt();
}

void
cpu_die(void)
{
	max_xtp();
	local_irq_disable();
	cpu_halt();
	/* Should never be here */
	BUG();
	for (;;);
}

irqreturn_t
handle_IPI (int irq, void *dev_id, struct pt_regs *regs)
{
	int this_cpu = get_cpu();
	unsigned long *pending_ipis = &__ia64_per_cpu_var(ipi_operation);
	unsigned long ops;

	mb();	/* Order interrupt and bit testing. */
	while ((ops = xchg(pending_ipis, 0)) != 0) {
		mb();	/* Order bit clearing and data access. */
		do {
			unsigned long which;

			which = ffz(~ops);
			ops &= ~(1 << which);

			switch (which) {
			      case IPI_CALL_FUNC:
			      {
				      struct call_data_struct *data;
				      void (*func)(void *info);
				      void *info;
				      int wait;

				      /* release the 'pointer lock' */
				      data = (struct call_data_struct *) call_data;
				      func = data->func;
				      info = data->info;
				      wait = data->wait;

				      mb();
				      atomic_inc(&data->started);
				      /*
				       * At this point the structure may be gone unless
				       * wait is true.
				       */
				      (*func)(info);

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

			      case IPI_CPU_STOP:
				stop_this_cpu();
				break;

			      default:
				printk(KERN_CRIT "Unknown IPI on CPU %d: %lu\n", this_cpu, which);
				break;
			}
		} while (ops);
		mb();	/* Order data access and bit testing. */
	}
	put_cpu();
	return IRQ_HANDLED;
}

/*
 * Called with preeemption disabled.
 */
static inline void
send_IPI_single (int dest_cpu, int op)
{
	set_bit(op, &per_cpu(ipi_operation, dest_cpu));
	platform_send_ipi(dest_cpu, IA64_IPI_VECTOR, IA64_IPI_DM_INT, 0);
}

/*
 * Called with preeemption disabled.
 */
static inline void
send_IPI_allbutself (int op)
{
	unsigned int i;

	for (i = 0; i < NR_CPUS; i++) {
		if (cpu_online(i) && i != smp_processor_id())
			send_IPI_single(i, op);
	}
}

/*
 * Called with preeemption disabled.
 */
static inline void
send_IPI_all (int op)
{
	int i;

	for (i = 0; i < NR_CPUS; i++)
		if (cpu_online(i))
			send_IPI_single(i, op);
}

/*
 * Called with preeemption disabled.
 */
static inline void
send_IPI_self (int op)
{
	send_IPI_single(smp_processor_id(), op);
}

/*
 * Called with preeemption disabled.
 */
void
smp_send_reschedule (int cpu)
{
	platform_send_ipi(cpu, IA64_IPI_RESCHEDULE, IA64_IPI_DM_INT, 0);
}

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

void
smp_flush_tlb_mm (struct mm_struct *mm)
{
	preempt_disable();
	/* this happens for the common case of a single-threaded fork():  */
	if (likely(mm == current->active_mm && atomic_read(&mm->mm_users) == 1))
	{
		local_finish_flush_tlb_mm(mm);
		preempt_enable();
		return;
	}

	preempt_enable();
	/*
	 * We could optimize this further by using mm->cpu_vm_mask to track which CPUs
	 * have been running in the address space.  It's not clear that this is worth the
	 * trouble though: to avoid races, we have to raise the IPI on the target CPU
	 * anyhow, and once a CPU is interrupted, the cost of local_flush_tlb_all() is
	 * rather trivial.
	 */
	on_each_cpu((void (*)(void *))local_finish_flush_tlb_mm, mm, 1, 1);
}

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

int
smp_call_function_single (int cpuid, void (*func) (void *info), void *info, int nonatomic,
			  int wait)
{
	struct call_data_struct data;
	int cpus = 1;
	int me = get_cpu(); /* prevent preemption and reschedule on another processor */

	if (cpuid == me) {
		printk(KERN_INFO "%s: trying to call self\n", __FUNCTION__);
		put_cpu();
		return -EBUSY;
	}

	data.func = func;
	data.info = info;
	atomic_set(&data.started, 0);
	data.wait = wait;
	if (wait)
		atomic_set(&data.finished, 0);

	spin_lock_bh(&call_lock);

	call_data = &data;
	mb();	/* ensure store to call_data precedes setting of IPI_CALL_FUNC */
  	send_IPI_single(cpuid, IPI_CALL_FUNC);

	/* Wait for response */
	while (atomic_read(&data.started) != cpus)
		cpu_relax();

	if (wait)
		while (atomic_read(&data.finished) != cpus)
			cpu_relax();
	call_data = NULL;

	spin_unlock_bh(&call_lock);
	put_cpu();
	return 0;
}
EXPORT_SYMBOL(smp_call_function_single);

/*
 * this function sends a 'generic call function' IPI to all other CPUs
 * in the system.
 */

/*
 *  [SUMMARY]	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.
 *  <nonatomic>	currently unused.
 *  <wait>	If true, wait (atomically) 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 are or have
 * executed.
 *
 * You must not call this function with disabled interrupts or from a
 * hardware interrupt handler or from a bottom half handler.
 */
int
smp_call_function (void (*func) (void *info), void *info, int nonatomic, int wait)
{
	struct call_data_struct data;
	int cpus = num_online_cpus()-1;

	if (!cpus)
		return 0;

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

	data.func = func;
	data.info = info;
	atomic_set(&data.started, 0);
	data.wait = wait;
	if (wait)
		atomic_set(&data.finished, 0);

	spin_lock(&call_lock);

	call_data = &data;
	mb();	/* ensure store to call_data precedes setting of IPI_CALL_FUNC */
	send_IPI_allbutself(IPI_CALL_FUNC);

	/* Wait for response */
	while (atomic_read(&data.started) != cpus)
		cpu_relax();

	if (wait)
		while (atomic_read(&data.finished) != cpus)
			cpu_relax();
	call_data = NULL;

	spin_unlock(&call_lock);
	return 0;
}
EXPORT_SYMBOL(smp_call_function);

/*
 * this function calls the 'stop' function on all other CPUs in the system.
 */
void
smp_send_stop (void)
{
	send_IPI_allbutself(IPI_CPU_STOP);
}

int __init
setup_profiling_timer (unsigned int multiplier)
{
	return -EINVAL;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* SMP Support
	3	*
	4	* Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
	5	* Copyright (C) 1999, 2001, 2003 David Mosberger-Tang <davidm@hpl.hp.com>
	6	*
	7	* Lots of stuff stolen from arch/alpha/kernel/smp.c
	8	*
	9	* 01/05/16 Rohit Seth <rohit.seth@intel.com> IA64-SMP functions. Reorganized
	10	* the existing code (on the lines of x86 port).
	11	* 00/09/11 David Mosberger <davidm@hpl.hp.com> Do loops_per_jiffy
	12	* calibration on each CPU.
	13	* 00/08/23 Asit Mallick <asit.k.mallick@intel.com> fixed logical processor id
	14	* 00/03/31 Rohit Seth <rohit.seth@intel.com> Fixes for Bootstrap Processor
	15	* & cpu_online_map now gets done here (instead of setup.c)
	16	* 99/10/05 davidm Update to bring it in sync with new command-line processing
	17	* scheme.
	18	* 10/13/00 Goutham Rao <goutham.rao@intel.com> Updated smp_call_function and
	19	* smp_call_function_single to resend IPI on timeouts
	20	*/
	21	#include <linux/module.h>
	22	#include <linux/kernel.h>
	23	#include <linux/sched.h>
	24	#include <linux/init.h>
	25	#include <linux/interrupt.h>
	26	#include <linux/smp.h>
	27	#include <linux/kernel_stat.h>
	28	#include <linux/mm.h>
	29	#include <linux/cache.h>
	30	#include <linux/delay.h>
	31	#include <linux/efi.h>
	32	#include <linux/bitops.h>
	33
	34	#include <asm/atomic.h>
	35	#include <asm/current.h>
	36	#include <asm/delay.h>
	37	#include <asm/machvec.h>
	38	#include <asm/io.h>
	39	#include <asm/irq.h>
	40	#include <asm/page.h>
	41	#include <asm/pgalloc.h>
	42	#include <asm/pgtable.h>
	43	#include <asm/processor.h>
	44	#include <asm/ptrace.h>
	45	#include <asm/sal.h>
	46	#include <asm/system.h>
	47	#include <asm/tlbflush.h>
	48	#include <asm/unistd.h>
	49	#include <asm/mca.h>
	50
	51	/*
	52	* Structure and data for smp_call_function(). This is designed to minimise static memory
	53	* requirements. It also looks cleaner.
	54	*/
	55	static __cacheline_aligned DEFINE_SPINLOCK(call_lock);
	56
	57	struct call_data_struct {
	58	void (func) (void info);
	59	void *info;
	60	long wait;
	61	atomic_t started;
	62	atomic_t finished;
	63	};
	64
65	static volatile struct call_data_struct *call_data;
66
67	#define IPI_CALL_FUNC 0
68	#define IPI_CPU_STOP 1
69
70	/* This needs to be cacheline aligned because it is written to by other CPUs. */
71	static DEFINE_PER_CPU(u64, ipi_operation) ____cacheline_aligned;
72
73	extern void cpu_halt (void);
74
75	void
76	lock_ipi_calllock(void)
77	{
78	spin_lock_irq(&call_lock);
79	}
80
81	void
82	unlock_ipi_calllock(void)
83	{
84	spin_unlock_irq(&call_lock);
85	}
86
87	static void
88	stop_this_cpu (void)
89	{
90	/*
91	* Remove this CPU:
92	*/
93	cpu_clear(smp_processor_id(), cpu_online_map);
94	max_xtp();
95	local_irq_disable();
96	cpu_halt();
97	}
98
99	void
100	cpu_die(void)
101	{
102	max_xtp();
103	local_irq_disable();
104	cpu_halt();
105	/* Should never be here */
106	BUG();
107	for (;;);
108	}
109
110	irqreturn_t
111	handle_IPI (int irq, void dev_id, struct pt_regs regs)
112	{
113	int this_cpu = get_cpu();
114	unsigned long *pending_ipis = &__ia64_per_cpu_var(ipi_operation);
115	unsigned long ops;
116
117	mb(); /* Order interrupt and bit testing. */
118	while ((ops = xchg(pending_ipis, 0)) != 0) {
119	mb(); /* Order bit clearing and data access. */
120	do {
121	unsigned long which;
122
123	which = ffz(~ops);
124	ops &= ~(1 << which);
125
126	switch (which) {
127	case IPI_CALL_FUNC:
128	{
129	struct call_data_struct *data;
130	void (func)(void info);
131	void *info;
132	int wait;
133
134	/* release the 'pointer lock' */
135	data = (struct call_data_struct *) call_data;
136	func = data->func;
137	info = data->info;
138	wait = data->wait;
139
140	mb();
141	atomic_inc(&data->started);
142	/*
143	* At this point the structure may be gone unless
144	* wait is true.
145	*/
146	(*func)(info);
147
148	/* Notify the sending CPU that the task is done. */
149	mb();
150	if (wait)
151	atomic_inc(&data->finished);
152	}
153	break;
154
155	case IPI_CPU_STOP:
156	stop_this_cpu();
157	break;
158
159	default:
160	printk(KERN_CRIT "Unknown IPI on CPU %d: %lu\n", this_cpu, which);
161	break;
162	}
163	} while (ops);
164	mb(); /* Order data access and bit testing. */
165	}
166	put_cpu();
167	return IRQ_HANDLED;
168	}
169
170	/*
171	* Called with preeemption disabled.
172	*/
173	static inline void
174	send_IPI_single (int dest_cpu, int op)
175	{
176	set_bit(op, &per_cpu(ipi_operation, dest_cpu));
177	platform_send_ipi(dest_cpu, IA64_IPI_VECTOR, IA64_IPI_DM_INT, 0);
178	}
179
180	/*
181	* Called with preeemption disabled.
182	*/
183	static inline void
184	send_IPI_allbutself (int op)
185	{
186	unsigned int i;
187
188	for (i = 0; i < NR_CPUS; i++) {
189	if (cpu_online(i) && i != smp_processor_id())
190	send_IPI_single(i, op);
191	}
192	}
193
194	/*
195	* Called with preeemption disabled.
196	*/
197	static inline void
198	send_IPI_all (int op)
199	{
200	int i;
201
202	for (i = 0; i < NR_CPUS; i++)
203	if (cpu_online(i))
204	send_IPI_single(i, op);
205	}
206
207	/*
208	* Called with preeemption disabled.
209	*/
210	static inline void
211	send_IPI_self (int op)
212	{
213	send_IPI_single(smp_processor_id(), op);
214	}
215
216	/*
217	* Called with preeemption disabled.
218	*/
219	void
220	smp_send_reschedule (int cpu)
221	{
222	platform_send_ipi(cpu, IA64_IPI_RESCHEDULE, IA64_IPI_DM_INT, 0);
223	}
224
225	void
226	smp_flush_tlb_all (void)
227	{
228	on_each_cpu((void ()(void ))local_flush_tlb_all, NULL, 1, 1);
229	}
230
231	void
232	smp_flush_tlb_mm (struct mm_struct *mm)
233	{
a68db763	234	preempt_disable();
1da177e4 LT	235	/* this happens for the common case of a single-threaded fork(): */
	236	if (likely(mm == current->active_mm && atomic_read(&mm->mm_users) == 1))
	237	{
	238	local_finish_flush_tlb_mm(mm);
a68db763	239	preempt_enable();
1da177e4 LT	240	return;
	241	}
	242
a68db763	243	preempt_enable();
1da177e4 LT	244	/*
	245	* We could optimize this further by using mm->cpu_vm_mask to track which CPUs
	246	* have been running in the address space. It's not clear that this is worth the
	247	* trouble though: to avoid races, we have to raise the IPI on the target CPU
	248	* anyhow, and once a CPU is interrupted, the cost of local_flush_tlb_all() is
	249	* rather trivial.
	250	*/
	251	on_each_cpu((void ()(void ))local_finish_flush_tlb_mm, mm, 1, 1);
	252	}
	253
	254	/*
	255	* Run a function on another CPU
	256	* <func> The function to run. This must be fast and non-blocking.
	257	* <info> An arbitrary pointer to pass to the function.
	258	* <nonatomic> Currently unused.
	259	* <wait> If true, wait until function has completed on other CPUs.
	260	* [RETURNS] 0 on success, else a negative status code.
	261	*
	262	* Does not return until the remote CPU is nearly ready to execute <func>
	263	* or is or has executed.
	264	*/
	265
	266	int
	267	smp_call_function_single (int cpuid, void (func) (void info), void *info, int nonatomic,
	268	int wait)
	269	{
	270	struct call_data_struct data;
	271	int cpus = 1;
	272	int me = get_cpu(); /* prevent preemption and reschedule on another processor */
	273
	274	if (cpuid == me) {
52a0de2c	275	printk(KERN_INFO "%s: trying to call self\n", __FUNCTION__);
1da177e4 LT	276	put_cpu();
	277	return -EBUSY;
	278	}
	279
	280	data.func = func;
	281	data.info = info;
	282	atomic_set(&data.started, 0);
	283	data.wait = wait;
	284	if (wait)
	285	atomic_set(&data.finished, 0);
	286
	287	spin_lock_bh(&call_lock);
	288
	289	call_data = &data;
	290	mb(); /* ensure store to call_data precedes setting of IPI_CALL_FUNC */
	291	send_IPI_single(cpuid, IPI_CALL_FUNC);
	292
	293	/* Wait for response */
	294	while (atomic_read(&data.started) != cpus)
	295	cpu_relax();
	296
	297	if (wait)
	298	while (atomic_read(&data.finished) != cpus)
	299	cpu_relax();
	300	call_data = NULL;
	301
	302	spin_unlock_bh(&call_lock);
	303	put_cpu();
	304	return 0;
	305	}
	306	EXPORT_SYMBOL(smp_call_function_single);
	307
	308	/*
	309	* this function sends a 'generic call function' IPI to all other CPUs
	310	* in the system.
	311	*/
	312
	313	/*
	314	* [SUMMARY] Run a function on all other CPUs.
	315	* <func> The function to run. This must be fast and non-blocking.
	316	* <info> An arbitrary pointer to pass to the function.
	317	* <nonatomic> currently unused.
	318	* <wait> If true, wait (atomically) until function has completed on other CPUs.
	319	* [RETURNS] 0 on success, else a negative status code.
	320	*
	321	* Does not return until remote CPUs are nearly ready to execute <func> or are or have
	322	* executed.
	323	*
	324	* You must not call this function with disabled interrupts or from a
	325	* hardware interrupt handler or from a bottom half handler.
	326	*/
	327	int
	328	smp_call_function (void (func) (void info), void *info, int nonatomic, int wait)
	329	{
	330	struct call_data_struct data;
	331	int cpus = num_online_cpus()-1;
	332
	333	if (!cpus)
	334	return 0;
	335
	336	/* Can deadlock when called with interrupts disabled */
	337	WARN_ON(irqs_disabled());
	338
	339	data.func = func;
340	data.info = info;
341	atomic_set(&data.started, 0);
342	data.wait = wait;
343	if (wait)
344	atomic_set(&data.finished, 0);
345
346	spin_lock(&call_lock);
347
348	call_data = &data;
349	mb(); /* ensure store to call_data precedes setting of IPI_CALL_FUNC */
350	send_IPI_allbutself(IPI_CALL_FUNC);
351
352	/* Wait for response */
353	while (atomic_read(&data.started) != cpus)
354	cpu_relax();
355
356	if (wait)
357	while (atomic_read(&data.finished) != cpus)
358	cpu_relax();
359	call_data = NULL;
360
361	spin_unlock(&call_lock);
362	return 0;
363	}
364	EXPORT_SYMBOL(smp_call_function);
365
366	/*
367	* this function calls the 'stop' function on all other CPUs in the system.
368	*/
369	void
370	smp_send_stop (void)
371	{
372	send_IPI_allbutself(IPI_CPU_STOP);
373	}
374
375	int __init
376	setup_profiling_timer (unsigned int multiplier)
377	{
378	return -EINVAL;
379	}