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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /arch/riscv/kernel/smpboot.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/riscv/kernel/smpboot.c')
-rw-r--r--arch/riscv/kernel/smpboot.c184
1 files changed, 184 insertions, 0 deletions
diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c
new file mode 100644
index 000000000..ddb2afba6
--- /dev/null
+++ b/arch/riscv/kernel/smpboot.c
@@ -0,0 +1,184 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * SMP initialisation and IPI support
+ * Based on arch/arm64/kernel/smp.c
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ * Copyright (C) 2015 Regents of the University of California
+ * Copyright (C) 2017 SiFive
+ */
+
+#include <linux/arch_topology.h>
+#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/of.h>
+#include <linux/sched/task_stack.h>
+#include <linux/sched/mm.h>
+#include <asm/cpu_ops.h>
+#include <asm/irq.h>
+#include <asm/mmu_context.h>
+#include <asm/numa.h>
+#include <asm/tlbflush.h>
+#include <asm/sections.h>
+#include <asm/sbi.h>
+#include <asm/smp.h>
+
+#include "head.h"
+
+static DECLARE_COMPLETION(cpu_running);
+
+void __init smp_prepare_boot_cpu(void)
+{
+}
+
+void __init smp_prepare_cpus(unsigned int max_cpus)
+{
+ int cpuid;
+ int ret;
+ unsigned int curr_cpuid;
+
+ init_cpu_topology();
+
+ curr_cpuid = smp_processor_id();
+ store_cpu_topology(curr_cpuid);
+ numa_store_cpu_info(curr_cpuid);
+ numa_add_cpu(curr_cpuid);
+
+ /* This covers non-smp usecase mandated by "nosmp" option */
+ if (max_cpus == 0)
+ return;
+
+ for_each_possible_cpu(cpuid) {
+ if (cpuid == curr_cpuid)
+ continue;
+ if (cpu_ops[cpuid]->cpu_prepare) {
+ ret = cpu_ops[cpuid]->cpu_prepare(cpuid);
+ if (ret)
+ continue;
+ }
+ set_cpu_present(cpuid, true);
+ numa_store_cpu_info(cpuid);
+ }
+}
+
+void __init setup_smp(void)
+{
+ struct device_node *dn;
+ unsigned long hart;
+ bool found_boot_cpu = false;
+ int cpuid = 1;
+ int rc;
+
+ cpu_set_ops(0);
+
+ for_each_of_cpu_node(dn) {
+ rc = riscv_of_processor_hartid(dn, &hart);
+ if (rc < 0)
+ continue;
+
+ if (hart == cpuid_to_hartid_map(0)) {
+ BUG_ON(found_boot_cpu);
+ found_boot_cpu = 1;
+ early_map_cpu_to_node(0, of_node_to_nid(dn));
+ continue;
+ }
+ if (cpuid >= NR_CPUS) {
+ pr_warn("Invalid cpuid [%d] for hartid [%lu]\n",
+ cpuid, hart);
+ continue;
+ }
+
+ cpuid_to_hartid_map(cpuid) = hart;
+ early_map_cpu_to_node(cpuid, of_node_to_nid(dn));
+ cpuid++;
+ }
+
+ BUG_ON(!found_boot_cpu);
+
+ if (cpuid > nr_cpu_ids)
+ pr_warn("Total number of cpus [%d] is greater than nr_cpus option value [%d]\n",
+ cpuid, nr_cpu_ids);
+
+ for (cpuid = 1; cpuid < nr_cpu_ids; cpuid++) {
+ if (cpuid_to_hartid_map(cpuid) != INVALID_HARTID) {
+ cpu_set_ops(cpuid);
+ set_cpu_possible(cpuid, true);
+ }
+ }
+}
+
+static int start_secondary_cpu(int cpu, struct task_struct *tidle)
+{
+ if (cpu_ops[cpu]->cpu_start)
+ return cpu_ops[cpu]->cpu_start(cpu, tidle);
+
+ return -EOPNOTSUPP;
+}
+
+int __cpu_up(unsigned int cpu, struct task_struct *tidle)
+{
+ int ret = 0;
+ tidle->thread_info.cpu = cpu;
+
+ ret = start_secondary_cpu(cpu, tidle);
+ if (!ret) {
+ wait_for_completion_timeout(&cpu_running,
+ msecs_to_jiffies(1000));
+
+ if (!cpu_online(cpu)) {
+ pr_crit("CPU%u: failed to come online\n", cpu);
+ ret = -EIO;
+ }
+ } else {
+ pr_crit("CPU%u: failed to start\n", cpu);
+ }
+
+ return ret;
+}
+
+void __init smp_cpus_done(unsigned int max_cpus)
+{
+}
+
+/*
+ * C entry point for a secondary processor.
+ */
+asmlinkage __visible void smp_callin(void)
+{
+ struct mm_struct *mm = &init_mm;
+ unsigned int curr_cpuid = smp_processor_id();
+
+ riscv_clear_ipi();
+
+ /* All kernel threads share the same mm context. */
+ mmgrab(mm);
+ current->active_mm = mm;
+
+ store_cpu_topology(curr_cpuid);
+ notify_cpu_starting(curr_cpuid);
+ numa_add_cpu(curr_cpuid);
+ set_cpu_online(curr_cpuid, 1);
+
+ /*
+ * Remote TLB flushes are ignored while the CPU is offline, so emit
+ * a local TLB flush right now just in case.
+ */
+ local_flush_tlb_all();
+ complete(&cpu_running);
+ /*
+ * Disable preemption before enabling interrupts, so we don't try to
+ * schedule a CPU that hasn't actually started yet.
+ */
+ local_irq_enable();
+ cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
+}