From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- arch/parisc/kernel/smp.c | 513 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 513 insertions(+) create mode 100644 arch/parisc/kernel/smp.c (limited to 'arch/parisc/kernel/smp.c') diff --git a/arch/parisc/kernel/smp.c b/arch/parisc/kernel/smp.c new file mode 100644 index 0000000000..2019c1f04b --- /dev/null +++ b/arch/parisc/kernel/smp.c @@ -0,0 +1,513 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* +** SMP Support +** +** Copyright (C) 1999 Walt Drummond +** Copyright (C) 1999 David Mosberger-Tang +** Copyright (C) 2001,2004 Grant Grundler +** +** Lots of stuff stolen from arch/alpha/kernel/smp.c +** ...and then parisc stole from arch/ia64/kernel/smp.c. Thanks David! :^) +** +** Thanks to John Curry and Ullas Ponnadi. I learned a lot from their work. +** -grant (1/12/2001) +** +*/ +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +#include +#include /* for CPU_IRQ_REGION and friends */ +#include +#include +#include +#include +#include +#include + +#undef DEBUG_SMP +#ifdef DEBUG_SMP +static int smp_debug_lvl = 0; +#define smp_debug(lvl, printargs...) \ + if (lvl >= smp_debug_lvl) \ + printk(printargs); +#else +#define smp_debug(lvl, ...) do { } while(0) +#endif /* DEBUG_SMP */ + +volatile struct task_struct *smp_init_current_idle_task; + +/* track which CPU is booting */ +static volatile int cpu_now_booting; + +static DEFINE_PER_CPU(spinlock_t, ipi_lock); + +enum ipi_message_type { + IPI_NOP=0, + IPI_RESCHEDULE=1, + IPI_CALL_FUNC, + IPI_CPU_START, + IPI_CPU_STOP, + IPI_CPU_TEST, +#ifdef CONFIG_KGDB + IPI_ENTER_KGDB, +#endif +}; + + +/********** SMP inter processor interrupt and communication routines */ + +#undef PER_CPU_IRQ_REGION +#ifdef PER_CPU_IRQ_REGION +/* XXX REVISIT Ignore for now. +** *May* need this "hook" to register IPI handler +** once we have perCPU ExtIntr switch tables. +*/ +static void +ipi_init(int cpuid) +{ +#error verify IRQ_OFFSET(IPI_IRQ) is ipi_interrupt() in new IRQ region + + if(cpu_online(cpuid) ) + { + switch_to_idle_task(current); + } + + return; +} +#endif + + +/* +** Yoink this CPU from the runnable list... +** +*/ +static void +halt_processor(void) +{ + /* REVISIT : redirect I/O Interrupts to another CPU? */ + /* REVISIT : does PM *know* this CPU isn't available? */ + set_cpu_online(smp_processor_id(), false); + local_irq_disable(); + __pdc_cpu_rendezvous(); + for (;;) + ; +} + + +irqreturn_t __irq_entry +ipi_interrupt(int irq, void *dev_id) +{ + int this_cpu = smp_processor_id(); + struct cpuinfo_parisc *p = &per_cpu(cpu_data, this_cpu); + unsigned long ops; + unsigned long flags; + + for (;;) { + spinlock_t *lock = &per_cpu(ipi_lock, this_cpu); + spin_lock_irqsave(lock, flags); + ops = p->pending_ipi; + p->pending_ipi = 0; + spin_unlock_irqrestore(lock, flags); + + mb(); /* Order bit clearing and data access. */ + + if (!ops) + break; + + while (ops) { + unsigned long which = ffz(~ops); + + ops &= ~(1 << which); + + switch (which) { + case IPI_NOP: + smp_debug(100, KERN_DEBUG "CPU%d IPI_NOP\n", this_cpu); + break; + + case IPI_RESCHEDULE: + smp_debug(100, KERN_DEBUG "CPU%d IPI_RESCHEDULE\n", this_cpu); + inc_irq_stat(irq_resched_count); + scheduler_ipi(); + break; + + case IPI_CALL_FUNC: + smp_debug(100, KERN_DEBUG "CPU%d IPI_CALL_FUNC\n", this_cpu); + inc_irq_stat(irq_call_count); + generic_smp_call_function_interrupt(); + break; + + case IPI_CPU_START: + smp_debug(100, KERN_DEBUG "CPU%d IPI_CPU_START\n", this_cpu); + break; + + case IPI_CPU_STOP: + smp_debug(100, KERN_DEBUG "CPU%d IPI_CPU_STOP\n", this_cpu); + halt_processor(); + break; + + case IPI_CPU_TEST: + smp_debug(100, KERN_DEBUG "CPU%d is alive!\n", this_cpu); + break; +#ifdef CONFIG_KGDB + case IPI_ENTER_KGDB: + smp_debug(100, KERN_DEBUG "CPU%d ENTER_KGDB\n", this_cpu); + kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs()); + break; +#endif + default: + printk(KERN_CRIT "Unknown IPI num on CPU%d: %lu\n", + this_cpu, which); + return IRQ_NONE; + } /* Switch */ + + /* before doing more, let in any pending interrupts */ + if (ops) { + local_irq_enable(); + local_irq_disable(); + } + } /* while (ops) */ + } + return IRQ_HANDLED; +} + + +static inline void +ipi_send(int cpu, enum ipi_message_type op) +{ + struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpu); + spinlock_t *lock = &per_cpu(ipi_lock, cpu); + unsigned long flags; + + spin_lock_irqsave(lock, flags); + p->pending_ipi |= 1 << op; + gsc_writel(IPI_IRQ - CPU_IRQ_BASE, p->hpa); + spin_unlock_irqrestore(lock, flags); +} + +static void +send_IPI_mask(const struct cpumask *mask, enum ipi_message_type op) +{ + int cpu; + + for_each_cpu(cpu, mask) + ipi_send(cpu, op); +} + +static inline void +send_IPI_single(int dest_cpu, enum ipi_message_type op) +{ + BUG_ON(dest_cpu == NO_PROC_ID); + + ipi_send(dest_cpu, op); +} + +static inline void +send_IPI_allbutself(enum ipi_message_type op) +{ + int i; + + preempt_disable(); + for_each_online_cpu(i) { + if (i != smp_processor_id()) + send_IPI_single(i, op); + } + preempt_enable(); +} + +#ifdef CONFIG_KGDB +void kgdb_roundup_cpus(void) +{ + send_IPI_allbutself(IPI_ENTER_KGDB); +} +#endif + +inline void +smp_send_stop(void) { send_IPI_allbutself(IPI_CPU_STOP); } + +void +arch_smp_send_reschedule(int cpu) { send_IPI_single(cpu, IPI_RESCHEDULE); } + +void +smp_send_all_nop(void) +{ + send_IPI_allbutself(IPI_NOP); +} + +void arch_send_call_function_ipi_mask(const struct cpumask *mask) +{ + send_IPI_mask(mask, IPI_CALL_FUNC); +} + +void arch_send_call_function_single_ipi(int cpu) +{ + send_IPI_single(cpu, IPI_CALL_FUNC); +} + +/* + * Called by secondaries to update state and initialize CPU registers. + */ +static void +smp_cpu_init(int cpunum) +{ + /* Set modes and Enable floating point coprocessor */ + init_per_cpu(cpunum); + + disable_sr_hashing(); + + mb(); + + /* Well, support 2.4 linux scheme as well. */ + if (cpu_online(cpunum)) { + extern void machine_halt(void); /* arch/parisc.../process.c */ + + printk(KERN_CRIT "CPU#%d already initialized!\n", cpunum); + machine_halt(); + } + + notify_cpu_starting(cpunum); + + set_cpu_online(cpunum, true); + + /* Initialise the idle task for this CPU */ + mmgrab(&init_mm); + current->active_mm = &init_mm; + BUG_ON(current->mm); + enter_lazy_tlb(&init_mm, current); + + init_IRQ(); /* make sure no IRQs are enabled or pending */ + start_cpu_itimer(); +} + + +/* + * Slaves start using C here. Indirectly called from smp_slave_stext. + * Do what start_kernel() and main() do for boot strap processor (aka monarch) + */ +void smp_callin(unsigned long pdce_proc) +{ + int slave_id = cpu_now_booting; + +#ifdef CONFIG_64BIT + WARN_ON(((unsigned long)(PAGE0->mem_pdc_hi) << 32 + | PAGE0->mem_pdc) != pdce_proc); +#endif + + smp_cpu_init(slave_id); + + flush_cache_all_local(); /* start with known state */ + flush_tlb_all_local(NULL); + + local_irq_enable(); /* Interrupts have been off until now */ + + cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); + + /* NOTREACHED */ + panic("smp_callin() AAAAaaaaahhhh....\n"); +} + +/* + * Bring one cpu online. + */ +static int smp_boot_one_cpu(int cpuid, struct task_struct *idle) +{ + const struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpuid); + long timeout; + +#ifdef CONFIG_HOTPLUG_CPU + int i; + + /* reset irq statistics for this CPU */ + memset(&per_cpu(irq_stat, cpuid), 0, sizeof(irq_cpustat_t)); + for (i = 0; i < NR_IRQS; i++) { + struct irq_desc *desc = irq_to_desc(i); + + if (desc && desc->kstat_irqs) + *per_cpu_ptr(desc->kstat_irqs, cpuid) = 0; + } +#endif + + /* wait until last booting CPU has started. */ + while (cpu_now_booting) + ; + + /* Let _start know what logical CPU we're booting + ** (offset into init_tasks[],cpu_data[]) + */ + cpu_now_booting = cpuid; + + /* + ** boot strap code needs to know the task address since + ** it also contains the process stack. + */ + smp_init_current_idle_task = idle ; + mb(); + + printk(KERN_INFO "Releasing cpu %d now, hpa=%lx\n", cpuid, p->hpa); + + /* + ** This gets PDC to release the CPU from a very tight loop. + ** + ** From the PA-RISC 2.0 Firmware Architecture Reference Specification: + ** "The MEM_RENDEZ vector specifies the location of OS_RENDEZ which + ** is executed after receiving the rendezvous signal (an interrupt to + ** EIR{0}). MEM_RENDEZ is valid only when it is nonzero and the + ** contents of memory are valid." + */ + gsc_writel(TIMER_IRQ - CPU_IRQ_BASE, p->hpa); + mb(); + + /* + * OK, wait a bit for that CPU to finish staggering about. + * Slave will set a bit when it reaches smp_cpu_init(). + * Once the "monarch CPU" sees the bit change, it can move on. + */ + for (timeout = 0; timeout < 10000; timeout++) { + if(cpu_online(cpuid)) { + /* Which implies Slave has started up */ + cpu_now_booting = 0; + goto alive ; + } + udelay(100); + barrier(); + } + printk(KERN_CRIT "SMP: CPU:%d is stuck.\n", cpuid); + return -1; + +alive: + /* Remember the Slave data */ + smp_debug(100, KERN_DEBUG "SMP: CPU:%d came alive after %ld _us\n", + cpuid, timeout * 100); + return 0; +} + +void __init smp_prepare_boot_cpu(void) +{ + int bootstrap_processor = per_cpu(cpu_data, 0).cpuid; + + /* Setup BSP mappings */ + printk(KERN_INFO "SMP: bootstrap CPU ID is %d\n", bootstrap_processor); + + set_cpu_online(bootstrap_processor, true); + set_cpu_present(bootstrap_processor, true); +} + + + +/* +** inventory.c:do_inventory() hasn't yet been run and thus we +** don't 'discover' the additional CPUs until later. +*/ +void __init smp_prepare_cpus(unsigned int max_cpus) +{ + int cpu; + + for_each_possible_cpu(cpu) + spin_lock_init(&per_cpu(ipi_lock, cpu)); + + init_cpu_present(cpumask_of(0)); +} + + +void __init smp_cpus_done(unsigned int cpu_max) +{ +} + + +int __cpu_up(unsigned int cpu, struct task_struct *tidle) +{ + if (cpu_online(cpu)) + return 0; + + if (num_online_cpus() < nr_cpu_ids && + num_online_cpus() < setup_max_cpus && + smp_boot_one_cpu(cpu, tidle)) + return -EIO; + + return cpu_online(cpu) ? 0 : -EIO; +} + +/* + * __cpu_disable runs on the processor to be shutdown. + */ +int __cpu_disable(void) +{ +#ifdef CONFIG_HOTPLUG_CPU + unsigned int cpu = smp_processor_id(); + + remove_cpu_topology(cpu); + + /* + * Take this CPU offline. Once we clear this, we can't return, + * and we must not schedule until we're ready to give up the cpu. + */ + set_cpu_online(cpu, false); + + /* Find a new timesync master */ + if (cpu == time_keeper_id) { + time_keeper_id = cpumask_first(cpu_online_mask); + pr_info("CPU %d is now promoted to time-keeper master\n", time_keeper_id); + } + + disable_percpu_irq(IPI_IRQ); + + irq_migrate_all_off_this_cpu(); + + flush_cache_all_local(); + flush_tlb_all_local(NULL); + + /* disable all irqs, including timer irq */ + local_irq_disable(); + + /* wait for next timer irq ... */ + mdelay(1000/HZ+100); + + /* ... and then clear all pending external irqs */ + set_eiem(0); + mtctl(~0UL, CR_EIRR); + mfctl(CR_EIRR); + mtctl(0, CR_EIRR); +#endif + return 0; +} + +/* + * called on the thread which is asking for a CPU to be shutdown - + * waits until shutdown has completed, or it is timed out. + */ +void __cpu_die(unsigned int cpu) +{ + pdc_cpu_rendezvous_lock(); +} + +void arch_cpuhp_cleanup_dead_cpu(unsigned int cpu) +{ + pr_info("CPU%u: is shutting down\n", cpu); + + /* set task's state to interruptible sleep */ + set_current_state(TASK_INTERRUPTIBLE); + schedule_timeout((IS_ENABLED(CONFIG_64BIT) ? 8:2) * HZ); + + pdc_cpu_rendezvous_unlock(); +} -- cgit v1.2.3