diff options
Diffstat (limited to 'arch/ia64/kernel/smp.c')
| -rw-r--r-- | arch/ia64/kernel/smp.c | 335 |
1 files changed, 335 insertions, 0 deletions
diff --git a/arch/ia64/kernel/smp.c b/arch/ia64/kernel/smp.c new file mode 100644 index 0000000000..ea4f009a23 --- /dev/null +++ b/arch/ia64/kernel/smp.c @@ -0,0 +1,335 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * 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 <linux/kexec.h> + +#include <linux/atomic.h> +#include <asm/current.h> +#include <asm/delay.h> +#include <asm/io.h> +#include <asm/irq.h> +#include <asm/page.h> +#include <asm/processor.h> +#include <asm/ptrace.h> +#include <asm/sal.h> +#include <asm/tlbflush.h> +#include <asm/unistd.h> +#include <asm/mca.h> +#include <asm/xtp.h> + +/* + * Note: alignment of 4 entries/cacheline was empirically determined + * to be a good tradeoff between hot cachelines & spreading the array + * across too many cacheline. + */ +static struct local_tlb_flush_counts { + unsigned int count; +} __attribute__((__aligned__(32))) local_tlb_flush_counts[NR_CPUS]; + +static DEFINE_PER_CPU_SHARED_ALIGNED(unsigned short [NR_CPUS], + shadow_flush_counts); + +#define IPI_CALL_FUNC 0 +#define IPI_CPU_STOP 1 +#define IPI_CALL_FUNC_SINGLE 2 +#define IPI_KDUMP_CPU_STOP 3 + +/* This needs to be cacheline aligned because it is written to by *other* CPUs. */ +static DEFINE_PER_CPU_SHARED_ALIGNED(unsigned long, ipi_operation); + +extern void cpu_halt (void); + +static void +stop_this_cpu(void) +{ + /* + * Remove this CPU: + */ + set_cpu_online(smp_processor_id(), false); + 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) +{ + 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_CPU_STOP: + stop_this_cpu(); + break; + case IPI_CALL_FUNC: + generic_smp_call_function_interrupt(); + break; + case IPI_CALL_FUNC_SINGLE: + generic_smp_call_function_single_interrupt(); + break; +#ifdef CONFIG_KEXEC + case IPI_KDUMP_CPU_STOP: + unw_init_running(kdump_cpu_freeze, NULL); + break; +#endif + 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 preemption disabled. + */ +static inline void +send_IPI_single (int dest_cpu, int op) +{ + set_bit(op, &per_cpu(ipi_operation, dest_cpu)); + ia64_send_ipi(dest_cpu, IA64_IPI_VECTOR, IA64_IPI_DM_INT, 0); +} + +/* + * Called with preemption 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 preemption disabled. + */ +static inline void +send_IPI_mask(const struct cpumask *mask, int op) +{ + unsigned int cpu; + + for_each_cpu(cpu, mask) { + send_IPI_single(cpu, op); + } +} + +/* + * Called with preemption disabled. + */ +static inline void +send_IPI_all (int op) +{ + int i; + + for_each_online_cpu(i) { + send_IPI_single(i, op); + } +} + +/* + * Called with preemption disabled. + */ +static inline void +send_IPI_self (int op) +{ + send_IPI_single(smp_processor_id(), op); +} + +#ifdef CONFIG_KEXEC +void +kdump_smp_send_stop(void) +{ + send_IPI_allbutself(IPI_KDUMP_CPU_STOP); +} + +void +kdump_smp_send_init(void) +{ + unsigned int cpu, self_cpu; + self_cpu = smp_processor_id(); + for_each_online_cpu(cpu) { + if (cpu != self_cpu) { + if(kdump_status[cpu] == 0) + ia64_send_ipi(cpu, 0, IA64_IPI_DM_INIT, 0); + } + } +} +#endif +/* + * Called with preemption disabled. + */ +void +arch_smp_send_reschedule (int cpu) +{ + ia64_send_ipi(cpu, IA64_IPI_RESCHEDULE, IA64_IPI_DM_INT, 0); +} +EXPORT_SYMBOL_GPL(arch_smp_send_reschedule); + +/* + * Called with preemption disabled. + */ +static void +smp_send_local_flush_tlb (int cpu) +{ + ia64_send_ipi(cpu, IA64_IPI_LOCAL_TLB_FLUSH, IA64_IPI_DM_INT, 0); +} + +void +smp_local_flush_tlb(void) +{ + /* + * Use atomic ops. Otherwise, the load/increment/store sequence from + * a "++" operation can have the line stolen between the load & store. + * The overhead of the atomic op in negligible in this case & offers + * significant benefit for the brief periods where lots of cpus + * are simultaneously flushing TLBs. + */ + ia64_fetchadd(1, &local_tlb_flush_counts[smp_processor_id()].count, acq); + local_flush_tlb_all(); +} + +#define FLUSH_DELAY 5 /* Usec backoff to eliminate excessive cacheline bouncing */ + +void +smp_flush_tlb_cpumask(cpumask_t xcpumask) +{ + unsigned short *counts = __ia64_per_cpu_var(shadow_flush_counts); + cpumask_t cpumask = xcpumask; + int mycpu, cpu, flush_mycpu = 0; + + preempt_disable(); + mycpu = smp_processor_id(); + + for_each_cpu(cpu, &cpumask) + counts[cpu] = local_tlb_flush_counts[cpu].count & 0xffff; + + mb(); + for_each_cpu(cpu, &cpumask) { + if (cpu == mycpu) + flush_mycpu = 1; + else + smp_send_local_flush_tlb(cpu); + } + + if (flush_mycpu) + smp_local_flush_tlb(); + + for_each_cpu(cpu, &cpumask) + while(counts[cpu] == (local_tlb_flush_counts[cpu].count & 0xffff)) + udelay(FLUSH_DELAY); + + preempt_enable(); +} + +void +smp_flush_tlb_all (void) +{ + on_each_cpu((void (*)(void *))local_flush_tlb_all, NULL, 1); +} + +void +smp_flush_tlb_mm (struct mm_struct *mm) +{ + cpumask_var_t cpus; + 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; + } + if (!alloc_cpumask_var(&cpus, GFP_ATOMIC)) { + smp_call_function((void (*)(void *))local_finish_flush_tlb_mm, + mm, 1); + } else { + cpumask_copy(cpus, mm_cpumask(mm)); + smp_call_function_many(cpus, + (void (*)(void *))local_finish_flush_tlb_mm, mm, 1); + free_cpumask_var(cpus); + } + local_irq_disable(); + local_finish_flush_tlb_mm(mm); + local_irq_enable(); + preempt_enable(); +} + +void arch_send_call_function_single_ipi(int cpu) +{ + send_IPI_single(cpu, IPI_CALL_FUNC_SINGLE); +} + +void arch_send_call_function_ipi_mask(const struct cpumask *mask) +{ + send_IPI_mask(mask, IPI_CALL_FUNC); +} + +/* + * this function calls the 'stop' function on all other CPUs in the system. + */ +void +smp_send_stop (void) +{ + send_IPI_allbutself(IPI_CPU_STOP); +} |