1 // SPDX-License-Identifier: GPL-2.0
3 #include <linux/module.h>
4 #include <linux/init.h>
5 #include <linux/kernel.h>
7 #include <linux/sched.h>
8 #include <linux/kernel_stat.h>
9 #include <linux/notifier.h>
10 #include <linux/cpu.h>
11 #include <linux/percpu.h>
12 #include <linux/delay.h>
13 #include <linux/err.h>
14 #include <linux/irq.h>
15 #include <linux/irq_work.h>
16 #include <linux/irqdomain.h>
18 #include <linux/seq_file.h>
19 #include <linux/sched/task_stack.h>
20 #include <linux/sched/mm.h>
21 #include <linux/sched/hotplug.h>
23 #include <asm/traps.h>
24 #include <asm/sections.h>
25 #include <asm/mmu_context.h>
26 #ifdef CONFIG_CPU_HAS_FPU
30 enum ipi_message_type {
38 struct ipi_data_struct {
39 unsigned long bits ____cacheline_aligned;
40 unsigned long stats[IPI_MAX] ____cacheline_aligned;
42 static DEFINE_PER_CPU(struct ipi_data_struct, ipi_data);
44 static irqreturn_t handle_ipi(int irq, void *dev)
46 unsigned long *stats = this_cpu_ptr(&ipi_data)->stats;
51 ops = xchg(&this_cpu_ptr(&ipi_data)->bits, 0);
55 if (ops & (1 << IPI_RESCHEDULE)) {
56 stats[IPI_RESCHEDULE]++;
60 if (ops & (1 << IPI_CALL_FUNC)) {
61 stats[IPI_CALL_FUNC]++;
62 generic_smp_call_function_interrupt();
65 if (ops & (1 << IPI_IRQ_WORK)) {
66 stats[IPI_IRQ_WORK]++;
70 BUG_ON((ops >> IPI_MAX) != 0);
76 static void (*send_arch_ipi)(const struct cpumask *mask);
79 void __init set_send_ipi(void (*func)(const struct cpumask *mask), int irq)
89 send_ipi_message(const struct cpumask *to_whom, enum ipi_message_type operation)
93 for_each_cpu(i, to_whom)
94 set_bit(operation, &per_cpu_ptr(&ipi_data, i)->bits);
97 send_arch_ipi(to_whom);
100 static const char * const ipi_names[] = {
101 [IPI_EMPTY] = "Empty interrupts",
102 [IPI_RESCHEDULE] = "Rescheduling interrupts",
103 [IPI_CALL_FUNC] = "Function call interrupts",
104 [IPI_IRQ_WORK] = "Irq work interrupts",
107 int arch_show_interrupts(struct seq_file *p, int prec)
111 for (i = 0; i < IPI_MAX; i++) {
112 seq_printf(p, "%*s%u:%s", prec - 1, "IPI", i,
113 prec >= 4 ? " " : "");
114 for_each_online_cpu(cpu)
115 seq_printf(p, "%10lu ",
116 per_cpu_ptr(&ipi_data, cpu)->stats[i]);
117 seq_printf(p, " %s\n", ipi_names[i]);
123 void arch_send_call_function_ipi_mask(struct cpumask *mask)
125 send_ipi_message(mask, IPI_CALL_FUNC);
128 void arch_send_call_function_single_ipi(int cpu)
130 send_ipi_message(cpumask_of(cpu), IPI_CALL_FUNC);
133 static void ipi_stop(void *unused)
138 void smp_send_stop(void)
140 on_each_cpu(ipi_stop, NULL, 1);
143 void smp_send_reschedule(int cpu)
145 send_ipi_message(cpumask_of(cpu), IPI_RESCHEDULE);
148 #ifdef CONFIG_IRQ_WORK
149 void arch_irq_work_raise(void)
151 send_ipi_message(cpumask_of(smp_processor_id()), IPI_IRQ_WORK);
155 void __init smp_prepare_boot_cpu(void)
159 void __init smp_prepare_cpus(unsigned int max_cpus)
163 static int ipi_dummy_dev;
165 void __init setup_smp_ipi(void)
172 rc = request_percpu_irq(ipi_irq, handle_ipi, "IPI Interrupt",
175 panic("%s IRQ request failed\n", __func__);
177 enable_percpu_irq(ipi_irq, 0);
180 void __init setup_smp(void)
182 struct device_node *node = NULL;
185 for_each_of_cpu_node(node) {
186 if (!of_device_is_available(node))
189 if (of_property_read_u32(node, "reg", &cpu))
195 set_cpu_possible(cpu, true);
196 set_cpu_present(cpu, true);
200 extern void _start_smp_secondary(void);
202 volatile unsigned int secondary_hint;
203 volatile unsigned int secondary_hint2;
204 volatile unsigned int secondary_ccr;
205 volatile unsigned int secondary_stack;
207 unsigned long secondary_msa1;
209 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
211 unsigned long mask = 1 << cpu;
214 (unsigned int) task_stack_page(tidle) + THREAD_SIZE - 8;
215 secondary_hint = mfcr("cr31");
216 secondary_hint2 = mfcr("cr<21, 1>");
217 secondary_ccr = mfcr("cr18");
218 secondary_msa1 = read_mmu_msa1();
221 * Because other CPUs are in reset status, we must flush data
222 * from cache to out and secondary CPUs use them in
223 * csky_start_secondary(void)
227 if (mask & mfcr("cr<29, 0>")) {
228 send_arch_ipi(cpumask_of(cpu));
230 /* Enable cpu in SMP reset ctrl reg */
231 mask |= mfcr("cr<29, 0>");
232 mtcr("cr<29, 0>", mask);
235 /* Wait for the cpu online */
236 while (!cpu_online(cpu));
243 void __init smp_cpus_done(unsigned int max_cpus)
247 int setup_profiling_timer(unsigned int multiplier)
252 void csky_start_secondary(void)
254 struct mm_struct *mm = &init_mm;
255 unsigned int cpu = smp_processor_id();
257 mtcr("cr31", secondary_hint);
258 mtcr("cr<21, 1>", secondary_hint2);
259 mtcr("cr18", secondary_ccr);
261 mtcr("vbr", vec_base);
264 write_mmu_pagemask(0);
265 TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir);
266 TLBMISS_HANDLER_SETUP_PGD_KERNEL(swapper_pg_dir);
268 #ifdef CONFIG_CPU_HAS_FPU
272 enable_percpu_irq(ipi_irq, 0);
276 current->active_mm = mm;
277 cpumask_set_cpu(cpu, mm_cpumask(mm));
279 notify_cpu_starting(cpu);
280 set_cpu_online(cpu, true);
282 pr_info("CPU%u Online: %s...\n", cpu, __func__);
285 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
288 #ifdef CONFIG_HOTPLUG_CPU
289 int __cpu_disable(void)
291 unsigned int cpu = smp_processor_id();
293 set_cpu_online(cpu, false);
295 irq_migrate_all_off_this_cpu();
297 clear_tasks_mm_cpumask(cpu);
302 void __cpu_die(unsigned int cpu)
304 if (!cpu_wait_death(cpu, 5)) {
305 pr_crit("CPU%u: shutdown failed\n", cpu);
308 pr_notice("CPU%u: shutdown\n", cpu);
311 void arch_cpu_idle_dead(void)
317 while (!secondary_stack)
325 "jmpi csky_start_secondary"
327 : "r" (secondary_stack));