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-rw-r--r--arch/loongarch/kernel/smp.c666
1 files changed, 666 insertions, 0 deletions
diff --git a/arch/loongarch/kernel/smp.c b/arch/loongarch/kernel/smp.c
new file mode 100644
index 000000000..434bfc1cd
--- /dev/null
+++ b/arch/loongarch/kernel/smp.c
@@ -0,0 +1,666 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ *
+ * Derived from MIPS:
+ * Copyright (C) 2000, 2001 Kanoj Sarcar
+ * Copyright (C) 2000, 2001 Ralf Baechle
+ * Copyright (C) 2000, 2001 Silicon Graphics, Inc.
+ * Copyright (C) 2000, 2001, 2003 Broadcom Corporation
+ */
+#include <linux/cpu.h>
+#include <linux/cpumask.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/seq_file.h>
+#include <linux/smp.h>
+#include <linux/threads.h>
+#include <linux/export.h>
+#include <linux/time.h>
+#include <linux/tracepoint.h>
+#include <linux/sched/hotplug.h>
+#include <linux/sched/task_stack.h>
+
+#include <asm/cpu.h>
+#include <asm/idle.h>
+#include <asm/loongson.h>
+#include <asm/mmu_context.h>
+#include <asm/numa.h>
+#include <asm/processor.h>
+#include <asm/setup.h>
+#include <asm/time.h>
+
+int __cpu_number_map[NR_CPUS]; /* Map physical to logical */
+EXPORT_SYMBOL(__cpu_number_map);
+
+int __cpu_logical_map[NR_CPUS]; /* Map logical to physical */
+EXPORT_SYMBOL(__cpu_logical_map);
+
+/* Number of threads (siblings) per CPU core */
+int smp_num_siblings = 1;
+EXPORT_SYMBOL(smp_num_siblings);
+
+/* Representing the threads (siblings) of each logical CPU */
+cpumask_t cpu_sibling_map[NR_CPUS] __read_mostly;
+EXPORT_SYMBOL(cpu_sibling_map);
+
+/* Representing the core map of multi-core chips of each logical CPU */
+cpumask_t cpu_core_map[NR_CPUS] __read_mostly;
+EXPORT_SYMBOL(cpu_core_map);
+
+static DECLARE_COMPLETION(cpu_starting);
+static DECLARE_COMPLETION(cpu_running);
+
+/*
+ * A logcal cpu mask containing only one VPE per core to
+ * reduce the number of IPIs on large MT systems.
+ */
+cpumask_t cpu_foreign_map[NR_CPUS] __read_mostly;
+EXPORT_SYMBOL(cpu_foreign_map);
+
+/* representing cpus for which sibling maps can be computed */
+static cpumask_t cpu_sibling_setup_map;
+
+/* representing cpus for which core maps can be computed */
+static cpumask_t cpu_core_setup_map;
+
+struct secondary_data cpuboot_data;
+static DEFINE_PER_CPU(int, cpu_state);
+
+enum ipi_msg_type {
+ IPI_RESCHEDULE,
+ IPI_CALL_FUNCTION,
+};
+
+static const char *ipi_types[NR_IPI] __tracepoint_string = {
+ [IPI_RESCHEDULE] = "Rescheduling interrupts",
+ [IPI_CALL_FUNCTION] = "Function call interrupts",
+};
+
+void show_ipi_list(struct seq_file *p, int prec)
+{
+ unsigned int cpu, i;
+
+ for (i = 0; i < NR_IPI; i++) {
+ seq_printf(p, "%*s%u:%s", prec - 1, "IPI", i, prec >= 4 ? " " : "");
+ for_each_online_cpu(cpu)
+ seq_printf(p, "%10u ", per_cpu(irq_stat, cpu).ipi_irqs[i]);
+ seq_printf(p, " LoongArch %d %s\n", i + 1, ipi_types[i]);
+ }
+}
+
+/* Send mailbox buffer via Mail_Send */
+static void csr_mail_send(uint64_t data, int cpu, int mailbox)
+{
+ uint64_t val;
+
+ /* Send high 32 bits */
+ val = IOCSR_MBUF_SEND_BLOCKING;
+ val |= (IOCSR_MBUF_SEND_BOX_HI(mailbox) << IOCSR_MBUF_SEND_BOX_SHIFT);
+ val |= (cpu << IOCSR_MBUF_SEND_CPU_SHIFT);
+ val |= (data & IOCSR_MBUF_SEND_H32_MASK);
+ iocsr_write64(val, LOONGARCH_IOCSR_MBUF_SEND);
+
+ /* Send low 32 bits */
+ val = IOCSR_MBUF_SEND_BLOCKING;
+ val |= (IOCSR_MBUF_SEND_BOX_LO(mailbox) << IOCSR_MBUF_SEND_BOX_SHIFT);
+ val |= (cpu << IOCSR_MBUF_SEND_CPU_SHIFT);
+ val |= (data << IOCSR_MBUF_SEND_BUF_SHIFT);
+ iocsr_write64(val, LOONGARCH_IOCSR_MBUF_SEND);
+};
+
+static u32 ipi_read_clear(int cpu)
+{
+ u32 action;
+
+ /* Load the ipi register to figure out what we're supposed to do */
+ action = iocsr_read32(LOONGARCH_IOCSR_IPI_STATUS);
+ /* Clear the ipi register to clear the interrupt */
+ iocsr_write32(action, LOONGARCH_IOCSR_IPI_CLEAR);
+ smp_mb();
+
+ return action;
+}
+
+static void ipi_write_action(int cpu, u32 action)
+{
+ unsigned int irq = 0;
+
+ while ((irq = ffs(action))) {
+ uint32_t val = IOCSR_IPI_SEND_BLOCKING;
+
+ val |= (irq - 1);
+ val |= (cpu << IOCSR_IPI_SEND_CPU_SHIFT);
+ iocsr_write32(val, LOONGARCH_IOCSR_IPI_SEND);
+ action &= ~BIT(irq - 1);
+ }
+}
+
+void loongson_send_ipi_single(int cpu, unsigned int action)
+{
+ ipi_write_action(cpu_logical_map(cpu), (u32)action);
+}
+
+void loongson_send_ipi_mask(const struct cpumask *mask, unsigned int action)
+{
+ unsigned int i;
+
+ for_each_cpu(i, mask)
+ ipi_write_action(cpu_logical_map(i), (u32)action);
+}
+
+/*
+ * This function sends a 'reschedule' IPI to another CPU.
+ * it goes straight through and wastes no time serializing
+ * anything. Worst case is that we lose a reschedule ...
+ */
+void smp_send_reschedule(int cpu)
+{
+ loongson_send_ipi_single(cpu, SMP_RESCHEDULE);
+}
+EXPORT_SYMBOL_GPL(smp_send_reschedule);
+
+irqreturn_t loongson_ipi_interrupt(int irq, void *dev)
+{
+ unsigned int action;
+ unsigned int cpu = smp_processor_id();
+
+ action = ipi_read_clear(cpu_logical_map(cpu));
+
+ if (action & SMP_RESCHEDULE) {
+ scheduler_ipi();
+ per_cpu(irq_stat, cpu).ipi_irqs[IPI_RESCHEDULE]++;
+ }
+
+ if (action & SMP_CALL_FUNCTION) {
+ generic_smp_call_function_interrupt();
+ per_cpu(irq_stat, cpu).ipi_irqs[IPI_CALL_FUNCTION]++;
+ }
+
+ return IRQ_HANDLED;
+}
+
+void __init loongson_smp_setup(void)
+{
+ cpu_data[0].core = cpu_logical_map(0) % loongson_sysconf.cores_per_package;
+ cpu_data[0].package = cpu_logical_map(0) / loongson_sysconf.cores_per_package;
+
+ iocsr_write32(0xffffffff, LOONGARCH_IOCSR_IPI_EN);
+ pr_info("Detected %i available CPU(s)\n", loongson_sysconf.nr_cpus);
+}
+
+void __init loongson_prepare_cpus(unsigned int max_cpus)
+{
+ int i = 0;
+
+ for (i = 0; i < loongson_sysconf.nr_cpus; i++) {
+ set_cpu_present(i, true);
+ csr_mail_send(0, __cpu_logical_map[i], 0);
+ }
+
+ per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
+}
+
+/*
+ * Setup the PC, SP, and TP of a secondary processor and start it running!
+ */
+void loongson_boot_secondary(int cpu, struct task_struct *idle)
+{
+ unsigned long entry;
+
+ pr_info("Booting CPU#%d...\n", cpu);
+
+ entry = __pa_symbol((unsigned long)&smpboot_entry);
+ cpuboot_data.stack = (unsigned long)__KSTK_TOS(idle);
+ cpuboot_data.thread_info = (unsigned long)task_thread_info(idle);
+
+ csr_mail_send(entry, cpu_logical_map(cpu), 0);
+
+ loongson_send_ipi_single(cpu, SMP_BOOT_CPU);
+}
+
+/*
+ * SMP init and finish on secondary CPUs
+ */
+void loongson_init_secondary(void)
+{
+ unsigned int cpu = smp_processor_id();
+ unsigned int imask = ECFGF_IP0 | ECFGF_IP1 | ECFGF_IP2 |
+ ECFGF_IPI | ECFGF_PMC | ECFGF_TIMER;
+
+ change_csr_ecfg(ECFG0_IM, imask);
+
+ iocsr_write32(0xffffffff, LOONGARCH_IOCSR_IPI_EN);
+
+#ifdef CONFIG_NUMA
+ numa_add_cpu(cpu);
+#endif
+ per_cpu(cpu_state, cpu) = CPU_ONLINE;
+ cpu_data[cpu].core =
+ cpu_logical_map(cpu) % loongson_sysconf.cores_per_package;
+ cpu_data[cpu].package =
+ cpu_logical_map(cpu) / loongson_sysconf.cores_per_package;
+}
+
+void loongson_smp_finish(void)
+{
+ local_irq_enable();
+ iocsr_write64(0, LOONGARCH_IOCSR_MBUF0);
+ pr_info("CPU#%d finished\n", smp_processor_id());
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+
+int loongson_cpu_disable(void)
+{
+ unsigned long flags;
+ unsigned int cpu = smp_processor_id();
+
+ if (io_master(cpu))
+ return -EBUSY;
+
+#ifdef CONFIG_NUMA
+ numa_remove_cpu(cpu);
+#endif
+ set_cpu_online(cpu, false);
+ calculate_cpu_foreign_map();
+ local_irq_save(flags);
+ irq_migrate_all_off_this_cpu();
+ clear_csr_ecfg(ECFG0_IM);
+ local_irq_restore(flags);
+ local_flush_tlb_all();
+
+ return 0;
+}
+
+void loongson_cpu_die(unsigned int cpu)
+{
+ while (per_cpu(cpu_state, cpu) != CPU_DEAD)
+ cpu_relax();
+
+ mb();
+}
+
+void play_dead(void)
+{
+ register uint64_t addr;
+ register void (*init_fn)(void);
+
+ idle_task_exit();
+ local_irq_enable();
+ set_csr_ecfg(ECFGF_IPI);
+ __this_cpu_write(cpu_state, CPU_DEAD);
+
+ __smp_mb();
+ do {
+ __asm__ __volatile__("idle 0\n\t");
+ addr = iocsr_read64(LOONGARCH_IOCSR_MBUF0);
+ } while (addr == 0);
+
+ init_fn = (void *)TO_CACHE(addr);
+ iocsr_write32(0xffffffff, LOONGARCH_IOCSR_IPI_CLEAR);
+
+ init_fn();
+ unreachable();
+}
+
+#endif
+
+/*
+ * Power management
+ */
+#ifdef CONFIG_PM
+
+static int loongson_ipi_suspend(void)
+{
+ return 0;
+}
+
+static void loongson_ipi_resume(void)
+{
+ iocsr_write32(0xffffffff, LOONGARCH_IOCSR_IPI_EN);
+}
+
+static struct syscore_ops loongson_ipi_syscore_ops = {
+ .resume = loongson_ipi_resume,
+ .suspend = loongson_ipi_suspend,
+};
+
+/*
+ * Enable boot cpu ipi before enabling nonboot cpus
+ * during syscore_resume.
+ */
+static int __init ipi_pm_init(void)
+{
+ register_syscore_ops(&loongson_ipi_syscore_ops);
+ return 0;
+}
+
+core_initcall(ipi_pm_init);
+#endif
+
+static inline void set_cpu_sibling_map(int cpu)
+{
+ int i;
+
+ cpumask_set_cpu(cpu, &cpu_sibling_setup_map);
+
+ if (smp_num_siblings <= 1)
+ cpumask_set_cpu(cpu, &cpu_sibling_map[cpu]);
+ else {
+ for_each_cpu(i, &cpu_sibling_setup_map) {
+ if (cpus_are_siblings(cpu, i)) {
+ cpumask_set_cpu(i, &cpu_sibling_map[cpu]);
+ cpumask_set_cpu(cpu, &cpu_sibling_map[i]);
+ }
+ }
+ }
+}
+
+static inline void set_cpu_core_map(int cpu)
+{
+ int i;
+
+ cpumask_set_cpu(cpu, &cpu_core_setup_map);
+
+ for_each_cpu(i, &cpu_core_setup_map) {
+ if (cpu_data[cpu].package == cpu_data[i].package) {
+ cpumask_set_cpu(i, &cpu_core_map[cpu]);
+ cpumask_set_cpu(cpu, &cpu_core_map[i]);
+ }
+ }
+}
+
+/*
+ * Calculate a new cpu_foreign_map mask whenever a
+ * new cpu appears or disappears.
+ */
+void calculate_cpu_foreign_map(void)
+{
+ int i, k, core_present;
+ cpumask_t temp_foreign_map;
+
+ /* Re-calculate the mask */
+ cpumask_clear(&temp_foreign_map);
+ for_each_online_cpu(i) {
+ core_present = 0;
+ for_each_cpu(k, &temp_foreign_map)
+ if (cpus_are_siblings(i, k))
+ core_present = 1;
+ if (!core_present)
+ cpumask_set_cpu(i, &temp_foreign_map);
+ }
+
+ for_each_online_cpu(i)
+ cpumask_andnot(&cpu_foreign_map[i],
+ &temp_foreign_map, &cpu_sibling_map[i]);
+}
+
+/* Preload SMP state for boot cpu */
+void smp_prepare_boot_cpu(void)
+{
+ unsigned int cpu, node, rr_node;
+
+ set_cpu_possible(0, true);
+ set_cpu_online(0, true);
+ set_my_cpu_offset(per_cpu_offset(0));
+
+ rr_node = first_node(node_online_map);
+ for_each_possible_cpu(cpu) {
+ node = early_cpu_to_node(cpu);
+
+ /*
+ * The mapping between present cpus and nodes has been
+ * built during MADT and SRAT parsing.
+ *
+ * If possible cpus = present cpus here, early_cpu_to_node
+ * will return valid node.
+ *
+ * If possible cpus > present cpus here (e.g. some possible
+ * cpus will be added by cpu-hotplug later), for possible but
+ * not present cpus, early_cpu_to_node will return NUMA_NO_NODE,
+ * and we just map them to online nodes in round-robin way.
+ * Once hotplugged, new correct mapping will be built for them.
+ */
+ if (node != NUMA_NO_NODE)
+ set_cpu_numa_node(cpu, node);
+ else {
+ set_cpu_numa_node(cpu, rr_node);
+ rr_node = next_node_in(rr_node, node_online_map);
+ }
+ }
+}
+
+/* called from main before smp_init() */
+void __init smp_prepare_cpus(unsigned int max_cpus)
+{
+ init_new_context(current, &init_mm);
+ current_thread_info()->cpu = 0;
+ loongson_prepare_cpus(max_cpus);
+ set_cpu_sibling_map(0);
+ set_cpu_core_map(0);
+ calculate_cpu_foreign_map();
+#ifndef CONFIG_HOTPLUG_CPU
+ init_cpu_present(cpu_possible_mask);
+#endif
+}
+
+int __cpu_up(unsigned int cpu, struct task_struct *tidle)
+{
+ loongson_boot_secondary(cpu, tidle);
+
+ /* Wait for CPU to start and be ready to sync counters */
+ if (!wait_for_completion_timeout(&cpu_starting,
+ msecs_to_jiffies(5000))) {
+ pr_crit("CPU%u: failed to start\n", cpu);
+ return -EIO;
+ }
+
+ /* Wait for CPU to finish startup & mark itself online before return */
+ wait_for_completion(&cpu_running);
+
+ return 0;
+}
+
+/*
+ * First C code run on the secondary CPUs after being started up by
+ * the master.
+ */
+asmlinkage void start_secondary(void)
+{
+ unsigned int cpu;
+
+ sync_counter();
+ cpu = raw_smp_processor_id();
+ set_my_cpu_offset(per_cpu_offset(cpu));
+ rcu_cpu_starting(cpu);
+
+ cpu_probe();
+ constant_clockevent_init();
+ loongson_init_secondary();
+
+ set_cpu_sibling_map(cpu);
+ set_cpu_core_map(cpu);
+
+ notify_cpu_starting(cpu);
+
+ /* Notify boot CPU that we're starting */
+ complete(&cpu_starting);
+
+ /* The CPU is running, now mark it online */
+ set_cpu_online(cpu, true);
+
+ calculate_cpu_foreign_map();
+
+ /*
+ * Notify boot CPU that we're up & online and it can safely return
+ * from __cpu_up()
+ */
+ complete(&cpu_running);
+
+ /*
+ * irq will be enabled in loongson_smp_finish(), enabling it too
+ * early is dangerous.
+ */
+ WARN_ON_ONCE(!irqs_disabled());
+ loongson_smp_finish();
+
+ cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
+}
+
+void __init smp_cpus_done(unsigned int max_cpus)
+{
+}
+
+static void stop_this_cpu(void *dummy)
+{
+ set_cpu_online(smp_processor_id(), false);
+ calculate_cpu_foreign_map();
+ local_irq_disable();
+ while (true);
+}
+
+void smp_send_stop(void)
+{
+ smp_call_function(stop_this_cpu, NULL, 0);
+}
+
+int setup_profiling_timer(unsigned int multiplier)
+{
+ return 0;
+}
+
+static void flush_tlb_all_ipi(void *info)
+{
+ local_flush_tlb_all();
+}
+
+void flush_tlb_all(void)
+{
+ on_each_cpu(flush_tlb_all_ipi, NULL, 1);
+}
+
+static void flush_tlb_mm_ipi(void *mm)
+{
+ local_flush_tlb_mm((struct mm_struct *)mm);
+}
+
+void flush_tlb_mm(struct mm_struct *mm)
+{
+ if (atomic_read(&mm->mm_users) == 0)
+ return; /* happens as a result of exit_mmap() */
+
+ preempt_disable();
+
+ if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
+ on_each_cpu_mask(mm_cpumask(mm), flush_tlb_mm_ipi, mm, 1);
+ } else {
+ unsigned int cpu;
+
+ for_each_online_cpu(cpu) {
+ if (cpu != smp_processor_id() && cpu_context(cpu, mm))
+ cpu_context(cpu, mm) = 0;
+ }
+ local_flush_tlb_mm(mm);
+ }
+
+ preempt_enable();
+}
+
+struct flush_tlb_data {
+ struct vm_area_struct *vma;
+ unsigned long addr1;
+ unsigned long addr2;
+};
+
+static void flush_tlb_range_ipi(void *info)
+{
+ struct flush_tlb_data *fd = info;
+
+ local_flush_tlb_range(fd->vma, fd->addr1, fd->addr2);
+}
+
+void flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
+{
+ struct mm_struct *mm = vma->vm_mm;
+
+ preempt_disable();
+ if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
+ struct flush_tlb_data fd = {
+ .vma = vma,
+ .addr1 = start,
+ .addr2 = end,
+ };
+
+ on_each_cpu_mask(mm_cpumask(mm), flush_tlb_range_ipi, &fd, 1);
+ } else {
+ unsigned int cpu;
+
+ for_each_online_cpu(cpu) {
+ if (cpu != smp_processor_id() && cpu_context(cpu, mm))
+ cpu_context(cpu, mm) = 0;
+ }
+ local_flush_tlb_range(vma, start, end);
+ }
+ preempt_enable();
+}
+
+static void flush_tlb_kernel_range_ipi(void *info)
+{
+ struct flush_tlb_data *fd = info;
+
+ local_flush_tlb_kernel_range(fd->addr1, fd->addr2);
+}
+
+void flush_tlb_kernel_range(unsigned long start, unsigned long end)
+{
+ struct flush_tlb_data fd = {
+ .addr1 = start,
+ .addr2 = end,
+ };
+
+ on_each_cpu(flush_tlb_kernel_range_ipi, &fd, 1);
+}
+
+static void flush_tlb_page_ipi(void *info)
+{
+ struct flush_tlb_data *fd = info;
+
+ local_flush_tlb_page(fd->vma, fd->addr1);
+}
+
+void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
+{
+ preempt_disable();
+ if ((atomic_read(&vma->vm_mm->mm_users) != 1) || (current->mm != vma->vm_mm)) {
+ struct flush_tlb_data fd = {
+ .vma = vma,
+ .addr1 = page,
+ };
+
+ on_each_cpu_mask(mm_cpumask(vma->vm_mm), flush_tlb_page_ipi, &fd, 1);
+ } else {
+ unsigned int cpu;
+
+ for_each_online_cpu(cpu) {
+ if (cpu != smp_processor_id() && cpu_context(cpu, vma->vm_mm))
+ cpu_context(cpu, vma->vm_mm) = 0;
+ }
+ local_flush_tlb_page(vma, page);
+ }
+ preempt_enable();
+}
+EXPORT_SYMBOL(flush_tlb_page);
+
+static void flush_tlb_one_ipi(void *info)
+{
+ unsigned long vaddr = (unsigned long) info;
+
+ local_flush_tlb_one(vaddr);
+}
+
+void flush_tlb_one(unsigned long vaddr)
+{
+ on_each_cpu(flush_tlb_one_ipi, (void *)vaddr, 1);
+}
+EXPORT_SYMBOL(flush_tlb_one);