/* * SMP Support * * Copyright (C) 1999 Walt Drummond <drummond@valinux.com> * Copyright (C) 1999, 2001 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 */#define __KERNEL_SYSCALLS__#include <linux/config.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/delay.h>#include <linux/cache.h>#include <asm/atomic.h>#include <asm/bitops.h>#include <asm/current.h>#include <asm/delay.h>#include <asm/efi.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/unistd.h>#include <asm/mca.h>/* The 'big kernel lock' */spinlock_t kernel_flag __cacheline_aligned_in_smp = SPIN_LOCK_UNLOCKED;/* * Structure and data for smp_call_function(). This is designed to minimise static memory * requirements. It also looks cleaner. */static spinlock_t call_lock = SPIN_LOCK_UNLOCKED;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		1static voidstop_this_cpu (void){	extern void cpu_halt (void);	/*	 * Remove this CPU:	 */	clear_bit(smp_processor_id(), &cpu_online_map);	max_xtp();	__cli();	cpu_halt();}voidhandle_IPI (int irq, void *dev_id, struct pt_regs *regs){	int this_cpu = smp_processor_id();	unsigned long *pending_ipis = &local_cpu_data->ipi_operation;	unsigned long ops;	/* Count this now; we may make a call that never returns. */	local_cpu_data->ipi_count++;	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;		} /* Switch */	  } while (ops);	  mb();	/* Order data access and bit testing. */	}}static inline voidsend_IPI_single (int dest_cpu, int op){	set_bit(op, &cpu_data(dest_cpu)->ipi_operation);	platform_send_ipi(dest_cpu, IA64_IPI_VECTOR, IA64_IPI_DM_INT, 0);}static inline voidsend_IPI_allbutself (int op){	int i;	for (i = 0; i < smp_num_cpus; i++) {		if (i != smp_processor_id())			send_IPI_single(i, op);	}}static inline voidsend_IPI_all (int op){	int i;	for (i = 0; i < smp_num_cpus; i++)		send_IPI_single(i, op);}static inline voidsend_IPI_self (int op){	send_IPI_single(smp_processor_id(), op);}voidsmp_send_reschedule (int cpu){	platform_send_ipi(cpu, IA64_IPI_RESCHEDULE, IA64_IPI_DM_INT, 0);}voidsmp_flush_tlb_all (void){	smp_call_function ((void (*)(void *))__flush_tlb_all,0,1,1);	__flush_tlb_all();}/* * 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. */intsmp_call_function_single (int cpuid, void (*func) (void *info), void *info, int nonatomic,			  int wait){	struct call_data_struct data;	int cpus = 1;	if (cpuid == smp_processor_id()) {		printk(__FUNCTION__" trying to call self\n");		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)		barrier();	if (wait)		while (atomic_read(&data.finished) != cpus)			barrier();	call_data = NULL;	spin_unlock_bh(&call_lock);	return 0;}/* * 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, you may call it from a bottom half handler. */intsmp_call_function (void (*func) (void *info), void *info, int nonatomic, int wait){	struct call_data_struct data;	int cpus = smp_num_cpus-1;	if (!cpus)		return 0;	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_allbutself(IPI_CALL_FUNC);	/* Wait for response */	while (atomic_read(&data.started) != cpus)		barrier();	if (wait)		while (atomic_read(&data.finished) != cpus)			barrier();	call_data = NULL;	spin_unlock_bh(&call_lock);	return 0;}voidsmp_do_timer (struct pt_regs *regs){	int user = user_mode(regs);	if (--local_cpu_data->prof_counter <= 0) {		local_cpu_data->prof_counter = local_cpu_data->prof_multiplier;		update_process_times(user);	}}/* * this function calls the 'stop' function on all other CPUs in the system. */voidsmp_send_stop (void){	send_IPI_allbutself(IPI_CPU_STOP);	smp_num_cpus = 1;}int __initsetup_profiling_timer (unsigned int multiplier){	return -EINVAL;}