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/*
* Copyright (C) 2014 Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
* Copyright (C) 2017 Stafford Horne <shorne@gmail.com>
*
* Based on arm64 and arc implementations
* Copyright (C) 2013 ARM Ltd.
* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
*
* This file is licensed under the terms of the GNU General Public License
* version 2. This program is licensed "as is" without any warranty of any
* kind, whether express or implied.
*/
#include <linux/smp.h>
#include <linux/cpu.h>
#include <linux/sched.h>
#include <linux/irq.h>
#include <asm/cpuinfo.h>
#include <asm/mmu_context.h>
#include <asm/tlbflush.h>
#include <asm/time.h>
static void (*smp_cross_call)(const struct cpumask *, unsigned int);
unsigned long secondary_release = -1;
struct thread_info *secondary_thread_info;
enum ipi_msg_type {
IPI_RESCHEDULE,
IPI_CALL_FUNC,
IPI_CALL_FUNC_SINGLE,
};
static DEFINE_SPINLOCK(boot_lock);
static void boot_secondary(unsigned int cpu, struct task_struct *idle)
{
/*
* set synchronisation state between this boot processor
* and the secondary one
*/
spin_lock(&boot_lock);
secondary_release = cpu;
/*
* now the secondary core is starting up let it run its
* calibrations, then wait for it to finish
*/
spin_unlock(&boot_lock);
}
void __init smp_prepare_boot_cpu(void)
{
}
void __init smp_init_cpus(void)
{
int i;
for (i = 0; i < NR_CPUS; i++)
set_cpu_possible(i, true);
}
void __init smp_prepare_cpus(unsigned int max_cpus)
{
int i;
/*
* Initialise the present map, which describes the set of CPUs
* actually populated at the present time.
*/
for (i = 0; i < max_cpus; i++)
set_cpu_present(i, true);
}
void __init smp_cpus_done(unsigned int max_cpus)
{
}
static DECLARE_COMPLETION(cpu_running);
int __cpu_up(unsigned int cpu, struct task_struct *idle)
{
if (smp_cross_call == NULL) {
pr_warn("CPU%u: failed to start, IPI controller missing",
cpu);
return -EIO;
}
secondary_thread_info = task_thread_info(idle);
current_pgd[cpu] = init_mm.pgd;
boot_secondary(cpu, idle);
if (!wait_for_completion_timeout(&cpu_running,
msecs_to_jiffies(1000))) {
pr_crit("CPU%u: failed to start\n", cpu);
return -EIO;
}
return 0;
}
asmlinkage __init void secondary_start_kernel(void)
{
struct mm_struct *mm = &init_mm;
unsigned int cpu = smp_processor_id();
/*
* All kernel threads share the same mm context; grab a
* reference and switch to it.
*/
atomic_inc(&mm->mm_count);
current->active_mm = mm;
cpumask_set_cpu(cpu, mm_cpumask(mm));
pr_info("CPU%u: Booted secondary processor\n", cpu);
setup_cpuinfo();
openrisc_clockevent_init();
notify_cpu_starting(cpu);
/*
* OK, now it's safe to let the boot CPU continue
*/
set_cpu_online(cpu, true);
complete(&cpu_running);
local_irq_enable();
preempt_disable();
/*
* OK, it's off to the idle thread for us
*/
cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
}
void handle_IPI(unsigned int ipi_msg)
{
unsigned int cpu = smp_processor_id();
switch (ipi_msg) {
case IPI_RESCHEDULE:
scheduler_ipi();
break;
case IPI_CALL_FUNC:
generic_smp_call_function_interrupt();
break;
case IPI_CALL_FUNC_SINGLE:
generic_smp_call_function_single_interrupt();
break;
default:
WARN(1, "CPU%u: Unknown IPI message 0x%x\n", cpu, ipi_msg);
break;
}
}
void smp_send_reschedule(int cpu)
{
smp_cross_call(cpumask_of(cpu), IPI_RESCHEDULE);
}
static void stop_this_cpu(void *dummy)
{
/* Remove this CPU */
set_cpu_online(smp_processor_id(), false);
local_irq_disable();
/* CPU Doze */
if (mfspr(SPR_UPR) & SPR_UPR_PMP)
mtspr(SPR_PMR, mfspr(SPR_PMR) | SPR_PMR_DME);
/* If that didn't work, infinite loop */
while (1)
;
}
void smp_send_stop(void)
{
smp_call_function(stop_this_cpu, NULL, 0);
}
/* not supported, yet */
int setup_profiling_timer(unsigned int multiplier)
{
return -EINVAL;
}
void __init set_smp_cross_call(void (*fn)(const struct cpumask *, unsigned int))
{
smp_cross_call = fn;
}
void arch_send_call_function_single_ipi(int cpu)
{
smp_cross_call(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE);
}
void arch_send_call_function_ipi_mask(const struct cpumask *mask)
{
smp_cross_call(mask, IPI_CALL_FUNC);
}
/* TLB flush operations - Performed on each CPU*/
static inline void ipi_flush_tlb_all(void *ignored)
{
local_flush_tlb_all();
}
void flush_tlb_all(void)
{
on_each_cpu(ipi_flush_tlb_all, NULL, 1);
}
/*
* FIXME: implement proper functionality instead of flush_tlb_all.
* *But*, as things currently stands, the local_tlb_flush_* functions will
* all boil down to local_tlb_flush_all anyway.
*/
void flush_tlb_mm(struct mm_struct *mm)
{
on_each_cpu(ipi_flush_tlb_all, NULL, 1);
}
void flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr)
{
on_each_cpu(ipi_flush_tlb_all, NULL, 1);
}
void flush_tlb_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
on_each_cpu(ipi_flush_tlb_all, NULL, 1);
}
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