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/riscv/kernel/smp.c | 334 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 334 insertions(+) create mode 100644 arch/riscv/kernel/smp.c (limited to 'arch/riscv/kernel/smp.c') diff --git a/arch/riscv/kernel/smp.c b/arch/riscv/kernel/smp.c new file mode 100644 index 0000000000..40420afbb1 --- /dev/null +++ b/arch/riscv/kernel/smp.c @@ -0,0 +1,334 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * SMP initialisation and IPI support + * Based on arch/arm64/kernel/smp.c + * + * Copyright (C) 2012 ARM Ltd. + * Copyright (C) 2015 Regents of the University of California + * Copyright (C) 2017 SiFive + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +enum ipi_message_type { + IPI_RESCHEDULE, + IPI_CALL_FUNC, + IPI_CPU_STOP, + IPI_CPU_CRASH_STOP, + IPI_IRQ_WORK, + IPI_TIMER, + IPI_MAX +}; + +unsigned long __cpuid_to_hartid_map[NR_CPUS] __ro_after_init = { + [0 ... NR_CPUS-1] = INVALID_HARTID +}; + +void __init smp_setup_processor_id(void) +{ + cpuid_to_hartid_map(0) = boot_cpu_hartid; +} + +static DEFINE_PER_CPU_READ_MOSTLY(int, ipi_dummy_dev); +static int ipi_virq_base __ro_after_init; +static int nr_ipi __ro_after_init = IPI_MAX; +static struct irq_desc *ipi_desc[IPI_MAX] __read_mostly; + +int riscv_hartid_to_cpuid(unsigned long hartid) +{ + int i; + + for (i = 0; i < NR_CPUS; i++) + if (cpuid_to_hartid_map(i) == hartid) + return i; + + return -ENOENT; +} + +static void ipi_stop(void) +{ + set_cpu_online(smp_processor_id(), false); + while (1) + wait_for_interrupt(); +} + +#ifdef CONFIG_KEXEC_CORE +static atomic_t waiting_for_crash_ipi = ATOMIC_INIT(0); + +static inline void ipi_cpu_crash_stop(unsigned int cpu, struct pt_regs *regs) +{ + crash_save_cpu(regs, cpu); + + atomic_dec(&waiting_for_crash_ipi); + + local_irq_disable(); + +#ifdef CONFIG_HOTPLUG_CPU + if (cpu_has_hotplug(cpu)) + cpu_ops[cpu]->cpu_stop(); +#endif + + for(;;) + wait_for_interrupt(); +} +#else +static inline void ipi_cpu_crash_stop(unsigned int cpu, struct pt_regs *regs) +{ + unreachable(); +} +#endif + +static void send_ipi_mask(const struct cpumask *mask, enum ipi_message_type op) +{ + __ipi_send_mask(ipi_desc[op], mask); +} + +static void send_ipi_single(int cpu, enum ipi_message_type op) +{ + __ipi_send_mask(ipi_desc[op], cpumask_of(cpu)); +} + +#ifdef CONFIG_IRQ_WORK +void arch_irq_work_raise(void) +{ + send_ipi_single(smp_processor_id(), IPI_IRQ_WORK); +} +#endif + +static irqreturn_t handle_IPI(int irq, void *data) +{ + int ipi = irq - ipi_virq_base; + + switch (ipi) { + case IPI_RESCHEDULE: + scheduler_ipi(); + break; + case IPI_CALL_FUNC: + generic_smp_call_function_interrupt(); + break; + case IPI_CPU_STOP: + ipi_stop(); + break; + case IPI_CPU_CRASH_STOP: + ipi_cpu_crash_stop(smp_processor_id(), get_irq_regs()); + break; + case IPI_IRQ_WORK: + irq_work_run(); + break; +#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST + case IPI_TIMER: + tick_receive_broadcast(); + break; +#endif + default: + pr_warn("CPU%d: unhandled IPI%d\n", smp_processor_id(), ipi); + break; + } + + return IRQ_HANDLED; +} + +void riscv_ipi_enable(void) +{ + int i; + + if (WARN_ON_ONCE(!ipi_virq_base)) + return; + + for (i = 0; i < nr_ipi; i++) + enable_percpu_irq(ipi_virq_base + i, 0); +} + +void riscv_ipi_disable(void) +{ + int i; + + if (WARN_ON_ONCE(!ipi_virq_base)) + return; + + for (i = 0; i < nr_ipi; i++) + disable_percpu_irq(ipi_virq_base + i); +} + +bool riscv_ipi_have_virq_range(void) +{ + return (ipi_virq_base) ? true : false; +} + +DEFINE_STATIC_KEY_FALSE(riscv_ipi_for_rfence); +EXPORT_SYMBOL_GPL(riscv_ipi_for_rfence); + +void riscv_ipi_set_virq_range(int virq, int nr, bool use_for_rfence) +{ + int i, err; + + if (WARN_ON(ipi_virq_base)) + return; + + WARN_ON(nr < IPI_MAX); + nr_ipi = min(nr, IPI_MAX); + ipi_virq_base = virq; + + /* Request IPIs */ + for (i = 0; i < nr_ipi; i++) { + err = request_percpu_irq(ipi_virq_base + i, handle_IPI, + "IPI", &ipi_dummy_dev); + WARN_ON(err); + + ipi_desc[i] = irq_to_desc(ipi_virq_base + i); + irq_set_status_flags(ipi_virq_base + i, IRQ_HIDDEN); + } + + /* Enabled IPIs for boot CPU immediately */ + riscv_ipi_enable(); + + /* Update RFENCE static key */ + if (use_for_rfence) + static_branch_enable(&riscv_ipi_for_rfence); + else + static_branch_disable(&riscv_ipi_for_rfence); +} + +static const char * const ipi_names[] = { + [IPI_RESCHEDULE] = "Rescheduling interrupts", + [IPI_CALL_FUNC] = "Function call interrupts", + [IPI_CPU_STOP] = "CPU stop interrupts", + [IPI_CPU_CRASH_STOP] = "CPU stop (for crash dump) interrupts", + [IPI_IRQ_WORK] = "IRQ work interrupts", + [IPI_TIMER] = "Timer broadcast interrupts", +}; + +void show_ipi_stats(struct seq_file *p, int prec) +{ + unsigned int cpu, i; + + for (i = 0; i < IPI_MAX; i++) { + seq_printf(p, "%*s%u:%s", prec - 1, "IPI", i, + prec >= 4 ? " " : ""); + for_each_online_cpu(cpu) + seq_printf(p, "%10u ", irq_desc_kstat_cpu(ipi_desc[i], cpu)); + seq_printf(p, " %s\n", ipi_names[i]); + } +} + +void arch_send_call_function_ipi_mask(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); +} + +#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST +void tick_broadcast(const struct cpumask *mask) +{ + send_ipi_mask(mask, IPI_TIMER); +} +#endif + +void smp_send_stop(void) +{ + unsigned long timeout; + + if (num_online_cpus() > 1) { + cpumask_t mask; + + cpumask_copy(&mask, cpu_online_mask); + cpumask_clear_cpu(smp_processor_id(), &mask); + + if (system_state <= SYSTEM_RUNNING) + pr_crit("SMP: stopping secondary CPUs\n"); + send_ipi_mask(&mask, IPI_CPU_STOP); + } + + /* Wait up to one second for other CPUs to stop */ + timeout = USEC_PER_SEC; + while (num_online_cpus() > 1 && timeout--) + udelay(1); + + if (num_online_cpus() > 1) + pr_warn("SMP: failed to stop secondary CPUs %*pbl\n", + cpumask_pr_args(cpu_online_mask)); +} + +#ifdef CONFIG_KEXEC_CORE +/* + * The number of CPUs online, not counting this CPU (which may not be + * fully online and so not counted in num_online_cpus()). + */ +static inline unsigned int num_other_online_cpus(void) +{ + unsigned int this_cpu_online = cpu_online(smp_processor_id()); + + return num_online_cpus() - this_cpu_online; +} + +void crash_smp_send_stop(void) +{ + static int cpus_stopped; + cpumask_t mask; + unsigned long timeout; + + /* + * This function can be called twice in panic path, but obviously + * we execute this only once. + */ + if (cpus_stopped) + return; + + cpus_stopped = 1; + + /* + * If this cpu is the only one alive at this point in time, online or + * not, there are no stop messages to be sent around, so just back out. + */ + if (num_other_online_cpus() == 0) + return; + + cpumask_copy(&mask, cpu_online_mask); + cpumask_clear_cpu(smp_processor_id(), &mask); + + atomic_set(&waiting_for_crash_ipi, num_other_online_cpus()); + + pr_crit("SMP: stopping secondary CPUs\n"); + send_ipi_mask(&mask, IPI_CPU_CRASH_STOP); + + /* Wait up to one second for other CPUs to stop */ + timeout = USEC_PER_SEC; + while ((atomic_read(&waiting_for_crash_ipi) > 0) && timeout--) + udelay(1); + + if (atomic_read(&waiting_for_crash_ipi) > 0) + pr_warn("SMP: failed to stop secondary CPUs %*pbl\n", + cpumask_pr_args(&mask)); +} + +bool smp_crash_stop_failed(void) +{ + return (atomic_read(&waiting_for_crash_ipi) > 0); +} +#endif + +void arch_smp_send_reschedule(int cpu) +{ + send_ipi_single(cpu, IPI_RESCHEDULE); +} +EXPORT_SYMBOL_GPL(arch_smp_send_reschedule); -- cgit v1.2.3