https://github.com/torvalds/linux
Tip revision: 7111951b8d4973bda27ff663f2cf18b663d15b48 authored by Linus Torvalds on 29 March 2020, 22:25:41 UTC
Linux 5.6
Linux 5.6
Tip revision: 7111951
smp.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
*
* Copyright (C) 2000, 2001 Kanoj Sarcar
* Copyright (C) 2000, 2001 Ralf Baechle
* Copyright (C) 2000, 2001 Silicon Graphics, Inc.
* Copyright (C) 2000, 2001, 2003 Broadcom Corporation
*/
#include <linux/cache.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/smp.h>
#include <linux/spinlock.h>
#include <linux/threads.h>
#include <linux/export.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/sched/mm.h>
#include <linux/cpumask.h>
#include <linux/cpu.h>
#include <linux/err.h>
#include <linux/ftrace.h>
#include <linux/irqdomain.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/atomic.h>
#include <asm/cpu.h>
#include <asm/ginvt.h>
#include <asm/processor.h>
#include <asm/idle.h>
#include <asm/r4k-timer.h>
#include <asm/mips-cps.h>
#include <asm/mmu_context.h>
#include <asm/time.h>
#include <asm/setup.h>
#include <asm/maar.h>
int __cpu_number_map[CONFIG_MIPS_NR_CPU_NR_MAP]; /* Map physical to logical */
EXPORT_SYMBOL(__cpu_number_map);
int __cpu_logical_map[NR_CPUS]; /* Map logical to physical */
EXPORT_SYMBOL(__cpu_logical_map);
/* Number of TCs (or siblings in Intel speak) per CPU core */
int smp_num_siblings = 1;
EXPORT_SYMBOL(smp_num_siblings);
/* representing the TCs (or siblings in Intel speak) of each logical CPU */
cpumask_t cpu_sibling_map[NR_CPUS] __read_mostly;
EXPORT_SYMBOL(cpu_sibling_map);
/* representing the core map of multi-core chips of each logical CPU */
cpumask_t cpu_core_map[NR_CPUS] __read_mostly;
EXPORT_SYMBOL(cpu_core_map);
static DECLARE_COMPLETION(cpu_starting);
static DECLARE_COMPLETION(cpu_running);
/*
* A logcal cpu mask containing only one VPE per core to
* reduce the number of IPIs on large MT systems.
*/
cpumask_t cpu_foreign_map[NR_CPUS] __read_mostly;
EXPORT_SYMBOL(cpu_foreign_map);
/* representing cpus for which sibling maps can be computed */
static cpumask_t cpu_sibling_setup_map;
/* representing cpus for which core maps can be computed */
static cpumask_t cpu_core_setup_map;
cpumask_t cpu_coherent_mask;
#ifdef CONFIG_GENERIC_IRQ_IPI
static struct irq_desc *call_desc;
static struct irq_desc *sched_desc;
#endif
static inline void set_cpu_sibling_map(int cpu)
{
int i;
cpumask_set_cpu(cpu, &cpu_sibling_setup_map);
if (smp_num_siblings > 1) {
for_each_cpu(i, &cpu_sibling_setup_map) {
if (cpus_are_siblings(cpu, i)) {
cpumask_set_cpu(i, &cpu_sibling_map[cpu]);
cpumask_set_cpu(cpu, &cpu_sibling_map[i]);
}
}
} else
cpumask_set_cpu(cpu, &cpu_sibling_map[cpu]);
}
static inline void set_cpu_core_map(int cpu)
{
int i;
cpumask_set_cpu(cpu, &cpu_core_setup_map);
for_each_cpu(i, &cpu_core_setup_map) {
if (cpu_data[cpu].package == cpu_data[i].package) {
cpumask_set_cpu(i, &cpu_core_map[cpu]);
cpumask_set_cpu(cpu, &cpu_core_map[i]);
}
}
}
/*
* Calculate a new cpu_foreign_map mask whenever a
* new cpu appears or disappears.
*/
void calculate_cpu_foreign_map(void)
{
int i, k, core_present;
cpumask_t temp_foreign_map;
/* Re-calculate the mask */
cpumask_clear(&temp_foreign_map);
for_each_online_cpu(i) {
core_present = 0;
for_each_cpu(k, &temp_foreign_map)
if (cpus_are_siblings(i, k))
core_present = 1;
if (!core_present)
cpumask_set_cpu(i, &temp_foreign_map);
}
for_each_online_cpu(i)
cpumask_andnot(&cpu_foreign_map[i],
&temp_foreign_map, &cpu_sibling_map[i]);
}
const struct plat_smp_ops *mp_ops;
EXPORT_SYMBOL(mp_ops);
void register_smp_ops(const struct plat_smp_ops *ops)
{
if (mp_ops)
printk(KERN_WARNING "Overriding previously set SMP ops\n");
mp_ops = ops;
}
#ifdef CONFIG_GENERIC_IRQ_IPI
void mips_smp_send_ipi_single(int cpu, unsigned int action)
{
mips_smp_send_ipi_mask(cpumask_of(cpu), action);
}
void mips_smp_send_ipi_mask(const struct cpumask *mask, unsigned int action)
{
unsigned long flags;
unsigned int core;
int cpu;
local_irq_save(flags);
switch (action) {
case SMP_CALL_FUNCTION:
__ipi_send_mask(call_desc, mask);
break;
case SMP_RESCHEDULE_YOURSELF:
__ipi_send_mask(sched_desc, mask);
break;
default:
BUG();
}
if (mips_cpc_present()) {
for_each_cpu(cpu, mask) {
if (cpus_are_siblings(cpu, smp_processor_id()))
continue;
core = cpu_core(&cpu_data[cpu]);
while (!cpumask_test_cpu(cpu, &cpu_coherent_mask)) {
mips_cm_lock_other_cpu(cpu, CM_GCR_Cx_OTHER_BLOCK_LOCAL);
mips_cpc_lock_other(core);
write_cpc_co_cmd(CPC_Cx_CMD_PWRUP);
mips_cpc_unlock_other();
mips_cm_unlock_other();
}
}
}
local_irq_restore(flags);
}
static irqreturn_t ipi_resched_interrupt(int irq, void *dev_id)
{
scheduler_ipi();
return IRQ_HANDLED;
}
static irqreturn_t ipi_call_interrupt(int irq, void *dev_id)
{
generic_smp_call_function_interrupt();
return IRQ_HANDLED;
}
static struct irqaction irq_resched = {
.handler = ipi_resched_interrupt,
.flags = IRQF_PERCPU,
.name = "IPI resched"
};
static struct irqaction irq_call = {
.handler = ipi_call_interrupt,
.flags = IRQF_PERCPU,
.name = "IPI call"
};
static void smp_ipi_init_one(unsigned int virq,
struct irqaction *action)
{
int ret;
irq_set_handler(virq, handle_percpu_irq);
ret = setup_irq(virq, action);
BUG_ON(ret);
}
static unsigned int call_virq, sched_virq;
int mips_smp_ipi_allocate(const struct cpumask *mask)
{
int virq;
struct irq_domain *ipidomain;
struct device_node *node;
node = of_irq_find_parent(of_root);
ipidomain = irq_find_matching_host(node, DOMAIN_BUS_IPI);
/*
* Some platforms have half DT setup. So if we found irq node but
* didn't find an ipidomain, try to search for one that is not in the
* DT.
*/
if (node && !ipidomain)
ipidomain = irq_find_matching_host(NULL, DOMAIN_BUS_IPI);
/*
* There are systems which use IPI IRQ domains, but only have one
* registered when some runtime condition is met. For example a Malta
* kernel may include support for GIC & CPU interrupt controller IPI
* IRQ domains, but if run on a system with no GIC & no MT ASE then
* neither will be supported or registered.
*
* We only have a problem if we're actually using multiple CPUs so fail
* loudly if that is the case. Otherwise simply return, skipping IPI
* setup, if we're running with only a single CPU.
*/
if (!ipidomain) {
BUG_ON(num_present_cpus() > 1);
return 0;
}
virq = irq_reserve_ipi(ipidomain, mask);
BUG_ON(!virq);
if (!call_virq)
call_virq = virq;
virq = irq_reserve_ipi(ipidomain, mask);
BUG_ON(!virq);
if (!sched_virq)
sched_virq = virq;
if (irq_domain_is_ipi_per_cpu(ipidomain)) {
int cpu;
for_each_cpu(cpu, mask) {
smp_ipi_init_one(call_virq + cpu, &irq_call);
smp_ipi_init_one(sched_virq + cpu, &irq_resched);
}
} else {
smp_ipi_init_one(call_virq, &irq_call);
smp_ipi_init_one(sched_virq, &irq_resched);
}
return 0;
}
int mips_smp_ipi_free(const struct cpumask *mask)
{
struct irq_domain *ipidomain;
struct device_node *node;
node = of_irq_find_parent(of_root);
ipidomain = irq_find_matching_host(node, DOMAIN_BUS_IPI);
/*
* Some platforms have half DT setup. So if we found irq node but
* didn't find an ipidomain, try to search for one that is not in the
* DT.
*/
if (node && !ipidomain)
ipidomain = irq_find_matching_host(NULL, DOMAIN_BUS_IPI);
BUG_ON(!ipidomain);
if (irq_domain_is_ipi_per_cpu(ipidomain)) {
int cpu;
for_each_cpu(cpu, mask) {
remove_irq(call_virq + cpu, &irq_call);
remove_irq(sched_virq + cpu, &irq_resched);
}
}
irq_destroy_ipi(call_virq, mask);
irq_destroy_ipi(sched_virq, mask);
return 0;
}
static int __init mips_smp_ipi_init(void)
{
if (num_possible_cpus() == 1)
return 0;
mips_smp_ipi_allocate(cpu_possible_mask);
call_desc = irq_to_desc(call_virq);
sched_desc = irq_to_desc(sched_virq);
return 0;
}
early_initcall(mips_smp_ipi_init);
#endif
/*
* First C code run on the secondary CPUs after being started up by
* the master.
*/
asmlinkage void start_secondary(void)
{
unsigned int cpu;
cpu_probe();
per_cpu_trap_init(false);
mips_clockevent_init();
mp_ops->init_secondary();
cpu_report();
maar_init();
/*
* XXX parity protection should be folded in here when it's converted
* to an option instead of something based on .cputype
*/
calibrate_delay();
preempt_disable();
cpu = smp_processor_id();
cpu_data[cpu].udelay_val = loops_per_jiffy;
cpumask_set_cpu(cpu, &cpu_coherent_mask);
notify_cpu_starting(cpu);
/* Notify boot CPU that we're starting & ready to sync counters */
complete(&cpu_starting);
synchronise_count_slave(cpu);
/* The CPU is running and counters synchronised, now mark it online */
set_cpu_online(cpu, true);
set_cpu_sibling_map(cpu);
set_cpu_core_map(cpu);
calculate_cpu_foreign_map();
/*
* Notify boot CPU that we're up & online and it can safely return
* from __cpu_up
*/
complete(&cpu_running);
/*
* irq will be enabled in ->smp_finish(), enabling it too early
* is dangerous.
*/
WARN_ON_ONCE(!irqs_disabled());
mp_ops->smp_finish();
cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
}
static void stop_this_cpu(void *dummy)
{
/*
* Remove this CPU:
*/
set_cpu_online(smp_processor_id(), false);
calculate_cpu_foreign_map();
local_irq_disable();
while (1);
}
void smp_send_stop(void)
{
smp_call_function(stop_this_cpu, NULL, 0);
}
void __init smp_cpus_done(unsigned int max_cpus)
{
}
/* called from main before smp_init() */
void __init smp_prepare_cpus(unsigned int max_cpus)
{
init_new_context(current, &init_mm);
current_thread_info()->cpu = 0;
mp_ops->prepare_cpus(max_cpus);
set_cpu_sibling_map(0);
set_cpu_core_map(0);
calculate_cpu_foreign_map();
#ifndef CONFIG_HOTPLUG_CPU
init_cpu_present(cpu_possible_mask);
#endif
cpumask_copy(&cpu_coherent_mask, cpu_possible_mask);
}
/* preload SMP state for boot cpu */
void smp_prepare_boot_cpu(void)
{
if (mp_ops->prepare_boot_cpu)
mp_ops->prepare_boot_cpu();
set_cpu_possible(0, true);
set_cpu_online(0, true);
}
int __cpu_up(unsigned int cpu, struct task_struct *tidle)
{
int err;
err = mp_ops->boot_secondary(cpu, tidle);
if (err)
return err;
/* Wait for CPU to start and be ready to sync counters */
if (!wait_for_completion_timeout(&cpu_starting,
msecs_to_jiffies(1000))) {
pr_crit("CPU%u: failed to start\n", cpu);
return -EIO;
}
synchronise_count_master(cpu);
/* Wait for CPU to finish startup & mark itself online before return */
wait_for_completion(&cpu_running);
return 0;
}
/* Not really SMP stuff ... */
int setup_profiling_timer(unsigned int multiplier)
{
return 0;
}
static void flush_tlb_all_ipi(void *info)
{
local_flush_tlb_all();
}
void flush_tlb_all(void)
{
if (cpu_has_mmid) {
htw_stop();
ginvt_full();
sync_ginv();
instruction_hazard();
htw_start();
return;
}
on_each_cpu(flush_tlb_all_ipi, NULL, 1);
}
static void flush_tlb_mm_ipi(void *mm)
{
drop_mmu_context((struct mm_struct *)mm);
}
/*
* Special Variant of smp_call_function for use by TLB functions:
*
* o No return value
* o collapses to normal function call on UP kernels
* o collapses to normal function call on systems with a single shared
* primary cache.
*/
static inline void smp_on_other_tlbs(void (*func) (void *info), void *info)
{
smp_call_function(func, info, 1);
}
static inline void smp_on_each_tlb(void (*func) (void *info), void *info)
{
preempt_disable();
smp_on_other_tlbs(func, info);
func(info);
preempt_enable();
}
/*
* The following tlb flush calls are invoked when old translations are
* being torn down, or pte attributes are changing. For single threaded
* address spaces, a new context is obtained on the current cpu, and tlb
* context on other cpus are invalidated to force a new context allocation
* at switch_mm time, should the mm ever be used on other cpus. For
* multithreaded address spaces, intercpu interrupts have to be sent.
* Another case where intercpu interrupts are required is when the target
* mm might be active on another cpu (eg debuggers doing the flushes on
* behalf of debugees, kswapd stealing pages from another process etc).
* Kanoj 07/00.
*/
void flush_tlb_mm(struct mm_struct *mm)
{
preempt_disable();
if (cpu_has_mmid) {
/*
* No need to worry about other CPUs - the ginvt in
* drop_mmu_context() will be globalized.
*/
} else if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
smp_on_other_tlbs(flush_tlb_mm_ipi, mm);
} else {
unsigned int cpu;
for_each_online_cpu(cpu) {
if (cpu != smp_processor_id() && cpu_context(cpu, mm))
set_cpu_context(cpu, mm, 0);
}
}
drop_mmu_context(mm);
preempt_enable();
}
struct flush_tlb_data {
struct vm_area_struct *vma;
unsigned long addr1;
unsigned long addr2;
};
static void flush_tlb_range_ipi(void *info)
{
struct flush_tlb_data *fd = info;
local_flush_tlb_range(fd->vma, fd->addr1, fd->addr2);
}
void flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
{
struct mm_struct *mm = vma->vm_mm;
unsigned long addr;
u32 old_mmid;
preempt_disable();
if (cpu_has_mmid) {
htw_stop();
old_mmid = read_c0_memorymapid();
write_c0_memorymapid(cpu_asid(0, mm));
mtc0_tlbw_hazard();
addr = round_down(start, PAGE_SIZE * 2);
end = round_up(end, PAGE_SIZE * 2);
do {
ginvt_va_mmid(addr);
sync_ginv();
addr += PAGE_SIZE * 2;
} while (addr < end);
write_c0_memorymapid(old_mmid);
instruction_hazard();
htw_start();
} else if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
struct flush_tlb_data fd = {
.vma = vma,
.addr1 = start,
.addr2 = end,
};
smp_on_other_tlbs(flush_tlb_range_ipi, &fd);
local_flush_tlb_range(vma, start, end);
} else {
unsigned int cpu;
int exec = vma->vm_flags & VM_EXEC;
for_each_online_cpu(cpu) {
/*
* flush_cache_range() will only fully flush icache if
* the VMA is executable, otherwise we must invalidate
* ASID without it appearing to has_valid_asid() as if
* mm has been completely unused by that CPU.
*/
if (cpu != smp_processor_id() && cpu_context(cpu, mm))
set_cpu_context(cpu, mm, !exec);
}
local_flush_tlb_range(vma, start, end);
}
preempt_enable();
}
static void flush_tlb_kernel_range_ipi(void *info)
{
struct flush_tlb_data *fd = info;
local_flush_tlb_kernel_range(fd->addr1, fd->addr2);
}
void flush_tlb_kernel_range(unsigned long start, unsigned long end)
{
struct flush_tlb_data fd = {
.addr1 = start,
.addr2 = end,
};
on_each_cpu(flush_tlb_kernel_range_ipi, &fd, 1);
}
static void flush_tlb_page_ipi(void *info)
{
struct flush_tlb_data *fd = info;
local_flush_tlb_page(fd->vma, fd->addr1);
}
void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
{
u32 old_mmid;
preempt_disable();
if (cpu_has_mmid) {
htw_stop();
old_mmid = read_c0_memorymapid();
write_c0_memorymapid(cpu_asid(0, vma->vm_mm));
mtc0_tlbw_hazard();
ginvt_va_mmid(page);
sync_ginv();
write_c0_memorymapid(old_mmid);
instruction_hazard();
htw_start();
} else if ((atomic_read(&vma->vm_mm->mm_users) != 1) ||
(current->mm != vma->vm_mm)) {
struct flush_tlb_data fd = {
.vma = vma,
.addr1 = page,
};
smp_on_other_tlbs(flush_tlb_page_ipi, &fd);
local_flush_tlb_page(vma, page);
} else {
unsigned int cpu;
for_each_online_cpu(cpu) {
/*
* flush_cache_page() only does partial flushes, so
* invalidate ASID without it appearing to
* has_valid_asid() as if mm has been completely unused
* by that CPU.
*/
if (cpu != smp_processor_id() && cpu_context(cpu, vma->vm_mm))
set_cpu_context(cpu, vma->vm_mm, 1);
}
local_flush_tlb_page(vma, page);
}
preempt_enable();
}
static void flush_tlb_one_ipi(void *info)
{
unsigned long vaddr = (unsigned long) info;
local_flush_tlb_one(vaddr);
}
void flush_tlb_one(unsigned long vaddr)
{
smp_on_each_tlb(flush_tlb_one_ipi, (void *) vaddr);
}
EXPORT_SYMBOL(flush_tlb_page);
EXPORT_SYMBOL(flush_tlb_one);
#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
static DEFINE_PER_CPU(atomic_t, tick_broadcast_count);
static DEFINE_PER_CPU(call_single_data_t, tick_broadcast_csd);
void tick_broadcast(const struct cpumask *mask)
{
atomic_t *count;
call_single_data_t *csd;
int cpu;
for_each_cpu(cpu, mask) {
count = &per_cpu(tick_broadcast_count, cpu);
csd = &per_cpu(tick_broadcast_csd, cpu);
if (atomic_inc_return(count) == 1)
smp_call_function_single_async(cpu, csd);
}
}
static void tick_broadcast_callee(void *info)
{
int cpu = smp_processor_id();
tick_receive_broadcast();
atomic_set(&per_cpu(tick_broadcast_count, cpu), 0);
}
static int __init tick_broadcast_init(void)
{
call_single_data_t *csd;
int cpu;
for (cpu = 0; cpu < NR_CPUS; cpu++) {
csd = &per_cpu(tick_broadcast_csd, cpu);
csd->func = tick_broadcast_callee;
}
return 0;
}
early_initcall(tick_broadcast_init);
#endif /* CONFIG_GENERIC_CLOCKEVENTS_BROADCAST */