1 // SPDX-License-Identifier: GPL-2.0-only
3 * SMP support for Hexagon
5 * Copyright (c) 2010-2012, The Linux Foundation. All rights reserved.
9 #include <linux/errno.h>
10 #include <linux/kernel.h>
11 #include <linux/init.h>
12 #include <linux/interrupt.h>
13 #include <linux/module.h>
14 #include <linux/percpu.h>
15 #include <linux/sched/mm.h>
16 #include <linux/smp.h>
17 #include <linux/spinlock.h>
18 #include <linux/cpu.h>
19 #include <linux/mm_types.h>
21 #include <asm/time.h> /* timer_interrupt */
22 #include <asm/hexagon_vm.h>
24 #define BASE_IPI_IRQ 26
27 * cpu_possible_mask needs to be filled out prior to setup_per_cpu_areas
28 * (which is prior to any of our smp_prepare_cpu crap), in order to set
29 * up the... per_cpu areas.
36 static DEFINE_PER_CPU(struct ipi_data, ipi_data);
38 static inline void __handle_ipi(unsigned long *ops, struct ipi_data *ipi,
41 unsigned long msg = 0;
43 msg = find_next_bit(ops, BITS_PER_LONG, msg+1);
52 generic_smp_call_function_interrupt();
66 } while (msg < BITS_PER_LONG);
69 /* Used for IPI call from other CPU's to unmask int */
70 void smp_vm_unmask_irq(void *info)
72 __vmintop_locen((long) info);
77 * This is based on Alpha's IPI stuff.
78 * Supposed to take (int, void*) as args now.
79 * Specifically, first arg is irq, second is the irq_desc.
82 irqreturn_t handle_ipi(int irq, void *desc)
84 int cpu = smp_processor_id();
85 struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
88 while ((ops = xchg(&ipi->bits, 0)) != 0)
89 __handle_ipi(&ops, ipi, cpu);
93 void send_ipi(const struct cpumask *cpumask, enum ipi_message_type msg)
99 local_irq_save(flags);
101 for_each_cpu(cpu, cpumask) {
102 struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
104 set_bit(msg, &ipi->bits);
105 /* Possible barrier here */
106 retval = __vmintop_post(BASE_IPI_IRQ+cpu);
109 printk(KERN_ERR "interrupt %ld not configured?\n",
114 local_irq_restore(flags);
117 void __init smp_prepare_boot_cpu(void)
122 * interrupts should already be disabled from the VM
123 * SP should already be correct; need to set THREADINFO_REG
124 * to point to current thread info
127 void start_secondary(void)
129 unsigned long thread_ptr;
130 unsigned int cpu, irq;
132 /* Calculate thread_info pointer from stack pointer */
133 __asm__ __volatile__(
138 thread_ptr = thread_ptr & ~(THREAD_SIZE-1);
140 __asm__ __volatile__(
141 QUOTED_THREADINFO_REG " = %0;\n"
146 /* Set the memory struct */
148 current->active_mm = &init_mm;
150 cpu = smp_processor_id();
152 irq = BASE_IPI_IRQ + cpu;
153 if (request_irq(irq, handle_ipi, IRQF_TRIGGER_RISING, "ipi_handler",
155 pr_err("Failed to request irq %u (ipi_handler)\n", irq);
157 /* Register the clock_event dummy */
158 setup_percpu_clockdev();
160 printk(KERN_INFO "%s cpu %d\n", __func__, current_thread_info()->cpu);
162 notify_cpu_starting(cpu);
164 set_cpu_online(cpu, true);
168 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
173 * called once for each present cpu
174 * apparently starts up the CPU and then
175 * maintains control until "cpu_online(cpu)" is set.
178 int __cpu_up(unsigned int cpu, struct task_struct *idle)
180 struct thread_info *thread = (struct thread_info *)idle->stack;
185 /* Boot to the head. */
186 stack_start = ((void *) thread) + THREAD_SIZE;
187 __vmstart(start_secondary, stack_start);
189 while (!cpu_online(cpu))
195 void __init smp_cpus_done(unsigned int max_cpus)
199 void __init smp_prepare_cpus(unsigned int max_cpus)
201 int i, irq = BASE_IPI_IRQ;
204 * should eventually have some sort of machine
205 * descriptor that has this stuff
208 /* Right now, let's just fake it. */
209 for (i = 0; i < max_cpus; i++)
210 set_cpu_present(i, true);
212 /* Also need to register the interrupts for IPI */
214 if (request_irq(irq, handle_ipi, IRQF_TRIGGER_RISING,
215 "ipi_handler", NULL))
216 pr_err("Failed to request irq %d (ipi_handler)\n", irq);
220 void smp_send_reschedule(int cpu)
222 send_ipi(cpumask_of(cpu), IPI_RESCHEDULE);
225 void smp_send_stop(void)
227 struct cpumask targets;
228 cpumask_copy(&targets, cpu_online_mask);
229 cpumask_clear_cpu(smp_processor_id(), &targets);
230 send_ipi(&targets, IPI_CPU_STOP);
233 void arch_send_call_function_single_ipi(int cpu)
235 send_ipi(cpumask_of(cpu), IPI_CALL_FUNC);
238 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
240 send_ipi(mask, IPI_CALL_FUNC);
243 int setup_profiling_timer(unsigned int multiplier)
248 void smp_start_cpus(void)
252 for (i = 0; i < NR_CPUS; i++)
253 set_cpu_possible(i, true);