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-rw-r--r--arch/csky/kernel/smp.c319
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