diff options
Diffstat (limited to 'arch/csky/kernel/smp.c')
-rw-r--r-- | arch/csky/kernel/smp.c | 319 |
1 files changed, 319 insertions, 0 deletions
diff --git a/arch/csky/kernel/smp.c b/arch/csky/kernel/smp.c new file mode 100644 index 0000000000..8e42352cbf --- /dev/null +++ b/arch/csky/kernel/smp.c @@ -0,0 +1,319 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/sched.h> +#include <linux/kernel_stat.h> +#include <linux/notifier.h> +#include <linux/cpu.h> +#include <linux/percpu.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/irq.h> +#include <linux/irq_work.h> +#include <linux/irqdomain.h> +#include <linux/of.h> +#include <linux/seq_file.h> +#include <linux/sched/task_stack.h> +#include <linux/sched/mm.h> +#include <linux/sched/hotplug.h> +#include <asm/irq.h> +#include <asm/traps.h> +#include <asm/sections.h> +#include <asm/mmu_context.h> +#ifdef CONFIG_CPU_HAS_FPU +#include <abi/fpu.h> +#endif + +enum ipi_message_type { + IPI_EMPTY, + IPI_RESCHEDULE, + IPI_CALL_FUNC, + IPI_IRQ_WORK, + IPI_MAX +}; + +struct ipi_data_struct { + unsigned long bits ____cacheline_aligned; + unsigned long stats[IPI_MAX] ____cacheline_aligned; +}; +static DEFINE_PER_CPU(struct ipi_data_struct, ipi_data); + +static irqreturn_t handle_ipi(int irq, void *dev) +{ + unsigned long *stats = this_cpu_ptr(&ipi_data)->stats; + + while (true) { + unsigned long ops; + + ops = xchg(&this_cpu_ptr(&ipi_data)->bits, 0); + if (ops == 0) + return IRQ_HANDLED; + + if (ops & (1 << IPI_RESCHEDULE)) { + stats[IPI_RESCHEDULE]++; + scheduler_ipi(); + } + + if (ops & (1 << IPI_CALL_FUNC)) { + stats[IPI_CALL_FUNC]++; + generic_smp_call_function_interrupt(); + } + + if (ops & (1 << IPI_IRQ_WORK)) { + stats[IPI_IRQ_WORK]++; + irq_work_run(); + } + + BUG_ON((ops >> IPI_MAX) != 0); + } + + return IRQ_HANDLED; +} + +static void (*send_arch_ipi)(const struct cpumask *mask); + +static int ipi_irq; +void __init set_send_ipi(void (*func)(const struct cpumask *mask), int irq) +{ + if (send_arch_ipi) + return; + + send_arch_ipi = func; + ipi_irq = irq; +} + +static void +send_ipi_message(const struct cpumask *to_whom, enum ipi_message_type operation) +{ + int i; + + for_each_cpu(i, to_whom) + set_bit(operation, &per_cpu_ptr(&ipi_data, i)->bits); + + smp_mb(); + send_arch_ipi(to_whom); +} + +static const char * const ipi_names[] = { + [IPI_EMPTY] = "Empty interrupts", + [IPI_RESCHEDULE] = "Rescheduling interrupts", + [IPI_CALL_FUNC] = "Function call interrupts", + [IPI_IRQ_WORK] = "Irq work interrupts", +}; + +int arch_show_interrupts(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, "%10lu ", + per_cpu_ptr(&ipi_data, cpu)->stats[i]); + seq_printf(p, " %s\n", ipi_names[i]); + } + + return 0; +} + +void arch_send_call_function_ipi_mask(struct cpumask *mask) +{ + send_ipi_message(mask, IPI_CALL_FUNC); +} + +void arch_send_call_function_single_ipi(int cpu) +{ + send_ipi_message(cpumask_of(cpu), IPI_CALL_FUNC); +} + +static void ipi_stop(void *unused) +{ + while (1); +} + +void smp_send_stop(void) +{ + on_each_cpu(ipi_stop, NULL, 1); +} + +void arch_smp_send_reschedule(int cpu) +{ + send_ipi_message(cpumask_of(cpu), IPI_RESCHEDULE); +} + +#ifdef CONFIG_IRQ_WORK +void arch_irq_work_raise(void) +{ + send_ipi_message(cpumask_of(smp_processor_id()), IPI_IRQ_WORK); +} +#endif + +void __init smp_prepare_boot_cpu(void) +{ +} + +void __init smp_prepare_cpus(unsigned int max_cpus) +{ +} + +static int ipi_dummy_dev; + +void __init setup_smp_ipi(void) +{ + int rc; + + if (ipi_irq == 0) + return; + + rc = request_percpu_irq(ipi_irq, handle_ipi, "IPI Interrupt", + &ipi_dummy_dev); + if (rc) + panic("%s IRQ request failed\n", __func__); + + enable_percpu_irq(ipi_irq, 0); +} + +void __init setup_smp(void) +{ + struct device_node *node = NULL; + unsigned int cpu; + + for_each_of_cpu_node(node) { + if (!of_device_is_available(node)) + continue; + + cpu = of_get_cpu_hwid(node, 0); + if (cpu >= NR_CPUS) + continue; + + set_cpu_possible(cpu, true); + set_cpu_present(cpu, true); + } +} + +extern void _start_smp_secondary(void); + +volatile unsigned int secondary_hint; +volatile unsigned int secondary_hint2; +volatile unsigned int secondary_ccr; +volatile unsigned int secondary_stack; +volatile unsigned int secondary_msa1; +volatile unsigned int secondary_pgd; + +int __cpu_up(unsigned int cpu, struct task_struct *tidle) +{ + unsigned long mask = 1 << cpu; + + secondary_stack = + (unsigned int) task_stack_page(tidle) + THREAD_SIZE - 8; + secondary_hint = mfcr("cr31"); + secondary_hint2 = mfcr("cr<21, 1>"); + secondary_ccr = mfcr("cr18"); + secondary_msa1 = read_mmu_msa1(); + secondary_pgd = mfcr("cr<29, 15>"); + + /* + * Because other CPUs are in reset status, we must flush data + * from cache to out and secondary CPUs use them in + * csky_start_secondary(void) + */ + mtcr("cr17", 0x22); + + if (mask & mfcr("cr<29, 0>")) { + send_arch_ipi(cpumask_of(cpu)); + } else { + /* Enable cpu in SMP reset ctrl reg */ + mask |= mfcr("cr<29, 0>"); + mtcr("cr<29, 0>", mask); + } + + /* Wait for the cpu online */ + while (!cpu_online(cpu)); + + secondary_stack = 0; + + return 0; +} + +void __init smp_cpus_done(unsigned int max_cpus) +{ +} + +void csky_start_secondary(void) +{ + struct mm_struct *mm = &init_mm; + unsigned int cpu = smp_processor_id(); + + mtcr("cr31", secondary_hint); + mtcr("cr<21, 1>", secondary_hint2); + mtcr("cr18", secondary_ccr); + + mtcr("vbr", vec_base); + + flush_tlb_all(); + write_mmu_pagemask(0); + +#ifdef CONFIG_CPU_HAS_FPU + init_fpu(); +#endif + + enable_percpu_irq(ipi_irq, 0); + + mmget(mm); + mmgrab(mm); + current->active_mm = mm; + cpumask_set_cpu(cpu, mm_cpumask(mm)); + + notify_cpu_starting(cpu); + set_cpu_online(cpu, true); + + pr_info("CPU%u Online: %s...\n", cpu, __func__); + + local_irq_enable(); + cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); +} + +#ifdef CONFIG_HOTPLUG_CPU +int __cpu_disable(void) +{ + unsigned int cpu = smp_processor_id(); + + set_cpu_online(cpu, false); + + irq_migrate_all_off_this_cpu(); + + clear_tasks_mm_cpumask(cpu); + + return 0; +} + +void arch_cpuhp_cleanup_dead_cpu(unsigned int cpu) +{ + pr_notice("CPU%u: shutdown\n", cpu); +} + +void __noreturn arch_cpu_idle_dead(void) +{ + idle_task_exit(); + + cpuhp_ap_report_dead(); + + while (!secondary_stack) + arch_cpu_idle(); + + raw_local_irq_disable(); + + asm volatile( + "mov sp, %0\n" + "mov r8, %0\n" + "jmpi csky_start_secondary" + : + : "r" (secondary_stack)); + + BUG(); +} +#endif |