/* * 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_each_online_cpu(i) { if (i != smp_processor_id()) send_IPI_single(i, op); } } /* * Called with preeemption disabled. */ static inline void send_IPI_all (int op) { int i; for_each_online_cpu(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; }