diff options
Diffstat (limited to 'arch/csky/kernel/smp.c')
| -rw-r--r-- | arch/csky/kernel/smp.c | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/arch/csky/kernel/smp.c b/arch/csky/kernel/smp.c new file mode 100644 index 000000000000..36ebaf9834e1 --- /dev/null +++ b/arch/csky/kernel/smp.c @@ -0,0 +1,237 @@ +// 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/irqdomain.h> +#include <linux/of.h> +#include <linux/sched/task_stack.h> +#include <linux/sched/mm.h> +#include <asm/irq.h> +#include <asm/traps.h> +#include <asm/sections.h> +#include <asm/mmu_context.h> +#include <asm/pgalloc.h> + +struct ipi_data_struct { + unsigned long bits ____cacheline_aligned; +}; +static DEFINE_PER_CPU(struct ipi_data_struct, ipi_data); + +enum ipi_message_type { + IPI_EMPTY, + IPI_RESCHEDULE, + IPI_CALL_FUNC, + IPI_MAX +}; + +static irqreturn_t handle_ipi(int irq, void *dev) +{ + 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)) + scheduler_ipi(); + + if (ops & (1 << IPI_CALL_FUNC)) + generic_smp_call_function_interrupt(); + + 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); +} + +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 smp_send_reschedule(int cpu) +{ + send_ipi_message(cpumask_of(cpu), IPI_RESCHEDULE); +} + +void __init smp_prepare_boot_cpu(void) +{ +} + +void __init smp_prepare_cpus(unsigned int max_cpus) +{ +} + +static void __init enable_smp_ipi(void) +{ + enable_percpu_irq(ipi_irq, 0); +} + +static int ipi_dummy_dev; +void __init setup_smp_ipi(void) +{ + int rc; + + if (ipi_irq == 0) + panic("%s IRQ mapping failed\n", __func__); + + rc = request_percpu_irq(ipi_irq, handle_ipi, "IPI Interrupt", + &ipi_dummy_dev); + if (rc) + panic("%s IRQ request failed\n", __func__); + + enable_smp_ipi(); +} + +void __init setup_smp(void) +{ + struct device_node *node = NULL; + int cpu; + + while ((node = of_find_node_by_type(node, "cpu"))) { + if (!of_device_is_available(node)) + continue; + + if (of_property_read_u32(node, "reg", &cpu)) + continue; + + 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_ccr; +volatile unsigned int secondary_stack; + +int __cpu_up(unsigned int cpu, struct task_struct *tidle) +{ + unsigned int tmp; + + secondary_stack = (unsigned int)tidle->stack + THREAD_SIZE; + + secondary_hint = mfcr("cr31"); + + secondary_ccr = mfcr("cr18"); + + /* + * 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); + + /* Enable cpu in SMP reset ctrl reg */ + tmp = mfcr("cr<29, 0>"); + tmp |= 1 << cpu; + mtcr("cr<29, 0>", tmp); + + /* Wait for the cpu online */ + while (!cpu_online(cpu)); + + secondary_stack = 0; + + return 0; +} + +void __init smp_cpus_done(unsigned int max_cpus) +{ +} + +int setup_profiling_timer(unsigned int multiplier) +{ + return -EINVAL; +} + +void csky_start_secondary(void) +{ + struct mm_struct *mm = &init_mm; + unsigned int cpu = smp_processor_id(); + + mtcr("cr31", secondary_hint); + mtcr("cr18", secondary_ccr); + + mtcr("vbr", vec_base); + + flush_tlb_all(); + write_mmu_pagemask(0); + TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir); + TLBMISS_HANDLER_SETUP_PGD_KERNEL(swapper_pg_dir); + + asid_cache(smp_processor_id()) = ASID_FIRST_VERSION; + +#ifdef CONFIG_CPU_HAS_FPU + init_fpu(); +#endif + + enable_smp_ipi(); + + 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(); + preempt_disable(); + cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); +} |