diff options
Diffstat (limited to 'arch/ia64/kernel/smp.c')
| -rw-r--r-- | arch/ia64/kernel/smp.c | 376 |
1 files changed, 376 insertions, 0 deletions
diff --git a/arch/ia64/kernel/smp.c b/arch/ia64/kernel/smp.c new file mode 100644 index 00000000000..953095e2ce1 --- /dev/null +++ b/arch/ia64/kernel/smp.c @@ -0,0 +1,376 @@ +/* + * 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) +{ + /* 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); + return; + } + + /* + * 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("%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; +} |