#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_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>");
mtcr("cr17", 0x22);
if (mask & mfcr("cr<29, 0>")) {
send_arch_ipi(cpumask_of(cpu));
} else {
mask |= mfcr("cr<29, 0>");
mtcr("cr<29, 0>", mask);
}
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
