From 991069865796f8ad31ee54aca8a0f1b7a522e94b Mon Sep 17 00:00:00 2001 From: Guo Ren Date: Wed, 5 Sep 2018 14:25:20 +0800 Subject: [PATCH] csky: SMP support This patch adds boot, ipi, hotplug codes for SMP. Signed-off-by: Guo Ren Cc: Marc Zyngier Cc: Mark Rutland Cc: Peter Zijlstra Reviewed-by: Arnd Bergmann --- arch/csky/include/asm/smp.h | 26 +++++ arch/csky/kernel/smp.c | 237 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 263 insertions(+) create mode 100644 arch/csky/include/asm/smp.h create mode 100644 arch/csky/kernel/smp.c diff --git a/arch/csky/include/asm/smp.h b/arch/csky/include/asm/smp.h new file mode 100644 index 0000000..4a929c4 --- /dev/null +++ b/arch/csky/include/asm/smp.h @@ -0,0 +1,26 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef __ASM_CSKY_SMP_H +#define __ASM_CSKY_SMP_H + +#include +#include +#include + +#ifdef CONFIG_SMP + +void __init setup_smp(void); + +void __init setup_smp_ipi(void); + +void arch_send_call_function_ipi_mask(struct cpumask *mask); + +void arch_send_call_function_single_ipi(int cpu); + +void __init set_send_ipi(void (*func)(const struct cpumask *mask), int irq); + +#define raw_smp_processor_id() (current_thread_info()->cpu) + +#endif /* CONFIG_SMP */ + +#endif /* __ASM_CSKY_SMP_H */ diff --git a/arch/csky/kernel/smp.c b/arch/csky/kernel/smp.c new file mode 100644 index 0000000..36ebaf9 --- /dev/null +++ b/arch/csky/kernel/smp.c @@ -0,0 +1,237 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +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); +} -- 2.7.4