Contributors: 72
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Catalin Marinas |
770 |
21.21% |
3 |
1.88% |
| Marc Zyngier |
352 |
9.69% |
8 |
5.00% |
| Doug Anderson |
350 |
9.64% |
6 |
3.75% |
| Lorenzo Pieralisi |
334 |
9.20% |
5 |
3.12% |
| Mark Rutland |
296 |
8.15% |
18 |
11.25% |
| Jonathan Cameron |
197 |
5.43% |
1 |
0.62% |
| Suzuki K. Poulose |
184 |
5.07% |
11 |
6.88% |
| Gavin Shan |
160 |
4.41% |
3 |
1.88% |
| Javi Merino |
133 |
3.66% |
1 |
0.62% |
| AKASHI Takahiro |
96 |
2.64% |
1 |
0.62% |
| James Morse |
90 |
2.48% |
5 |
3.12% |
| Julien Thierry |
68 |
1.87% |
2 |
1.25% |
| Nico Pitre |
62 |
1.71% |
1 |
0.62% |
| Hanjun Guo |
56 |
1.54% |
3 |
1.88% |
| Will Deacon |
55 |
1.51% |
11 |
6.88% |
| Ashwin Chaugule |
36 |
0.99% |
1 |
0.62% |
| Larry Bassel |
34 |
0.94% |
1 |
0.62% |
| Cristian Marussi |
31 |
0.85% |
2 |
1.25% |
| Sudeep Holla |
28 |
0.77% |
4 |
2.50% |
| Ganapatrao Kulkarni |
22 |
0.61% |
1 |
0.62% |
| Anshuman Khandual |
18 |
0.50% |
1 |
0.62% |
| Jan Glauber |
17 |
0.47% |
1 |
0.62% |
| David Daney |
16 |
0.44% |
1 |
0.62% |
| Thomas Gleixner |
16 |
0.44% |
6 |
3.75% |
| ruanjinjie |
14 |
0.39% |
1 |
0.62% |
| Kefeng Wang |
13 |
0.36% |
3 |
1.88% |
| Mark Brown |
13 |
0.36% |
1 |
0.62% |
| Josh Poimboeuf |
10 |
0.28% |
3 |
1.88% |
| Aaro Koskinen |
9 |
0.25% |
1 |
0.62% |
| Rob Herring |
9 |
0.25% |
3 |
1.88% |
| Al Stone |
9 |
0.25% |
3 |
1.88% |
| Sebastian Andrzej Siewior |
9 |
0.25% |
1 |
0.62% |
| David Brazdil |
9 |
0.25% |
2 |
1.25% |
| Steve Capper |
8 |
0.22% |
1 |
0.62% |
| Ingo Molnar |
7 |
0.19% |
3 |
1.88% |
| Jean-Philippe Brucker |
7 |
0.19% |
1 |
0.62% |
| Andrey Konovalov |
7 |
0.19% |
3 |
1.88% |
| Rusty Russell |
6 |
0.17% |
1 |
0.62% |
| Ard Biesheuvel |
5 |
0.14% |
2 |
1.25% |
| Andre Przywara |
5 |
0.14% |
1 |
0.62% |
| Keith Busch |
5 |
0.14% |
1 |
0.62% |
| Pierre Gondois |
5 |
0.14% |
1 |
0.62% |
| D Scott Phillips |
5 |
0.14% |
1 |
0.62% |
| Qian Cai |
4 |
0.11% |
1 |
0.62% |
| Hector Martin |
4 |
0.11% |
1 |
0.62% |
| Phil Auld |
4 |
0.11% |
1 |
0.62% |
| Jonas Rabenstein |
4 |
0.11% |
1 |
0.62% |
| Zhen Lei |
3 |
0.08% |
1 |
0.62% |
| Frédéric Weisbecker |
3 |
0.08% |
2 |
1.25% |
| Geoff Levand |
3 |
0.08% |
1 |
0.62% |
| Peter Zijlstra |
2 |
0.06% |
1 |
0.62% |
| Daniel R Thompson |
2 |
0.06% |
1 |
0.62% |
| Gustavo A. R. Silva |
2 |
0.06% |
1 |
0.62% |
| Nobuhiro Iwamatsu |
2 |
0.06% |
1 |
0.62% |
| Yue haibing |
2 |
0.06% |
1 |
0.62% |
| Graeme Gregory |
2 |
0.06% |
1 |
0.62% |
| Hoeun Ryu |
2 |
0.06% |
1 |
0.62% |
| Puranjay Mohan |
2 |
0.06% |
1 |
0.62% |
| Vegard Nossum |
1 |
0.03% |
1 |
0.62% |
| Valentin Schneider |
1 |
0.03% |
1 |
0.62% |
| Zou Wei |
1 |
0.03% |
1 |
0.62% |
| Jiang Liu |
1 |
0.03% |
1 |
0.62% |
| Lee Jones |
1 |
0.03% |
1 |
0.62% |
| Paul E. McKenney |
1 |
0.03% |
1 |
0.62% |
| Yang Yingliang |
1 |
0.03% |
1 |
0.62% |
| Joël Porquet |
1 |
0.03% |
1 |
0.62% |
| Alexey Dobriyan |
1 |
0.03% |
1 |
0.62% |
| Mark Salter |
1 |
0.03% |
1 |
0.62% |
| JiSheng Zhang |
1 |
0.03% |
1 |
0.62% |
| Jayachandran C |
1 |
0.03% |
1 |
0.62% |
| Dmitry Torokhov |
1 |
0.03% |
1 |
0.62% |
| Zhizhou Zhang |
1 |
0.03% |
1 |
0.62% |
| Total |
3631 |
|
160 |
|
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// SPDX-License-Identifier: GPL-2.0-only
/*
* SMP initialisation and IPI support
* Based on arch/arm/kernel/smp.c
*
* Copyright (C) 2012 ARM Ltd.
*/
#include <linux/acpi.h>
#include <linux/arm_sdei.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/sched/mm.h>
#include <linux/sched/hotplug.h>
#include <linux/sched/task_stack.h>
#include <linux/interrupt.h>
#include <linux/cache.h>
#include <linux/profile.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/err.h>
#include <linux/cpu.h>
#include <linux/smp.h>
#include <linux/seq_file.h>
#include <linux/irq.h>
#include <linux/irqchip/arm-gic-v3.h>
#include <linux/percpu.h>
#include <linux/clockchips.h>
#include <linux/completion.h>
#include <linux/of.h>
#include <linux/irq_work.h>
#include <linux/kernel_stat.h>
#include <linux/kexec.h>
#include <linux/kgdb.h>
#include <linux/kvm_host.h>
#include <linux/nmi.h>
#include <asm/alternative.h>
#include <asm/atomic.h>
#include <asm/cacheflush.h>
#include <asm/cpu.h>
#include <asm/cputype.h>
#include <asm/cpu_ops.h>
#include <asm/daifflags.h>
#include <asm/kvm_mmu.h>
#include <asm/mmu_context.h>
#include <asm/numa.h>
#include <asm/processor.h>
#include <asm/smp_plat.h>
#include <asm/sections.h>
#include <asm/tlbflush.h>
#include <asm/ptrace.h>
#include <asm/virt.h>
#include <trace/events/ipi.h>
/*
* as from 2.5, kernels no longer have an init_tasks structure
* so we need some other way of telling a new secondary core
* where to place its SVC stack
*/
struct secondary_data secondary_data;
/* Number of CPUs which aren't online, but looping in kernel text. */
static int cpus_stuck_in_kernel;
enum ipi_msg_type {
IPI_RESCHEDULE,
IPI_CALL_FUNC,
IPI_CPU_STOP,
IPI_CPU_STOP_NMI,
IPI_TIMER,
IPI_IRQ_WORK,
NR_IPI,
/*
* Any enum >= NR_IPI and < MAX_IPI is special and not tracable
* with trace_ipi_*
*/
IPI_CPU_BACKTRACE = NR_IPI,
IPI_KGDB_ROUNDUP,
MAX_IPI
};
static int ipi_irq_base __ro_after_init;
static int nr_ipi __ro_after_init = NR_IPI;
static struct irq_desc *ipi_desc[MAX_IPI] __ro_after_init;
static bool crash_stop;
static void ipi_setup(int cpu);
#ifdef CONFIG_HOTPLUG_CPU
static void ipi_teardown(int cpu);
static int op_cpu_kill(unsigned int cpu);
#else
static inline int op_cpu_kill(unsigned int cpu)
{
return -ENOSYS;
}
#endif
/*
* Boot a secondary CPU, and assign it the specified idle task.
* This also gives us the initial stack to use for this CPU.
*/
static int boot_secondary(unsigned int cpu, struct task_struct *idle)
{
const struct cpu_operations *ops = get_cpu_ops(cpu);
if (ops->cpu_boot)
return ops->cpu_boot(cpu);
return -EOPNOTSUPP;
}
static DECLARE_COMPLETION(cpu_running);
int __cpu_up(unsigned int cpu, struct task_struct *idle)
{
int ret;
long status;
/*
* We need to tell the secondary core where to find its stack and the
* page tables.
*/
secondary_data.task = idle;
update_cpu_boot_status(CPU_MMU_OFF);
/* Now bring the CPU into our world */
ret = boot_secondary(cpu, idle);
if (ret) {
if (ret != -EPERM)
pr_err("CPU%u: failed to boot: %d\n", cpu, ret);
return ret;
}
/*
* CPU was successfully started, wait for it to come online or
* time out.
*/
wait_for_completion_timeout(&cpu_running,
msecs_to_jiffies(5000));
if (cpu_online(cpu))
return 0;
pr_crit("CPU%u: failed to come online\n", cpu);
secondary_data.task = NULL;
status = READ_ONCE(secondary_data.status);
if (status == CPU_MMU_OFF)
status = READ_ONCE(__early_cpu_boot_status);
switch (status & CPU_BOOT_STATUS_MASK) {
default:
pr_err("CPU%u: failed in unknown state : 0x%lx\n",
cpu, status);
cpus_stuck_in_kernel++;
break;
case CPU_KILL_ME:
if (!op_cpu_kill(cpu)) {
pr_crit("CPU%u: died during early boot\n", cpu);
break;
}
pr_crit("CPU%u: may not have shut down cleanly\n", cpu);
fallthrough;
case CPU_STUCK_IN_KERNEL:
pr_crit("CPU%u: is stuck in kernel\n", cpu);
if (status & CPU_STUCK_REASON_52_BIT_VA)
pr_crit("CPU%u: does not support 52-bit VAs\n", cpu);
if (status & CPU_STUCK_REASON_NO_GRAN) {
pr_crit("CPU%u: does not support %luK granule\n",
cpu, PAGE_SIZE / SZ_1K);
}
cpus_stuck_in_kernel++;
break;
case CPU_PANIC_KERNEL:
panic("CPU%u detected unsupported configuration\n", cpu);
}
return -EIO;
}
static void init_gic_priority_masking(void)
{
u32 cpuflags;
if (WARN_ON(!gic_enable_sre()))
return;
cpuflags = read_sysreg(daif);
WARN_ON(!(cpuflags & PSR_I_BIT));
WARN_ON(!(cpuflags & PSR_F_BIT));
gic_write_pmr(GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET);
}
/*
* This is the secondary CPU boot entry. We're using this CPUs
* idle thread stack, but a set of temporary page tables.
*/
asmlinkage notrace void secondary_start_kernel(void)
{
u64 mpidr = read_cpuid_mpidr() & MPIDR_HWID_BITMASK;
struct mm_struct *mm = &init_mm;
const struct cpu_operations *ops;
unsigned int cpu = smp_processor_id();
/*
* All kernel threads share the same mm context; grab a
* reference and switch to it.
*/
mmgrab(mm);
current->active_mm = mm;
/*
* TTBR0 is only used for the identity mapping at this stage. Make it
* point to zero page to avoid speculatively fetching new entries.
*/
cpu_uninstall_idmap();
if (system_uses_irq_prio_masking())
init_gic_priority_masking();
rcutree_report_cpu_starting(cpu);
trace_hardirqs_off();
/*
* If the system has established the capabilities, make sure
* this CPU ticks all of those. If it doesn't, the CPU will
* fail to come online.
*/
check_local_cpu_capabilities();
ops = get_cpu_ops(cpu);
if (ops->cpu_postboot)
ops->cpu_postboot();
/*
* Log the CPU info before it is marked online and might get read.
*/
cpuinfo_store_cpu();
store_cpu_topology(cpu);
/*
* Enable GIC and timers.
*/
notify_cpu_starting(cpu);
ipi_setup(cpu);
numa_add_cpu(cpu);
/*
* OK, now it's safe to let the boot CPU continue. Wait for
* the CPU migration code to notice that the CPU is online
* before we continue.
*/
pr_info("CPU%u: Booted secondary processor 0x%010lx [0x%08x]\n",
cpu, (unsigned long)mpidr,
read_cpuid_id());
update_cpu_boot_status(CPU_BOOT_SUCCESS);
set_cpu_online(cpu, true);
complete(&cpu_running);
/*
* Secondary CPUs enter the kernel with all DAIF exceptions masked.
*
* As with setup_arch() we must unmask Debug and SError exceptions, and
* as the root irqchip has already been detected and initialized we can
* unmask IRQ and FIQ at the same time.
*/
local_daif_restore(DAIF_PROCCTX);
/*
* OK, it's off to the idle thread for us
*/
cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
}
#ifdef CONFIG_HOTPLUG_CPU
static int op_cpu_disable(unsigned int cpu)
{
const struct cpu_operations *ops = get_cpu_ops(cpu);
/*
* If we don't have a cpu_die method, abort before we reach the point
* of no return. CPU0 may not have an cpu_ops, so test for it.
*/
if (!ops || !ops->cpu_die)
return -EOPNOTSUPP;
/*
* We may need to abort a hot unplug for some other mechanism-specific
* reason.
*/
if (ops->cpu_disable)
return ops->cpu_disable(cpu);
return 0;
}
/*
* __cpu_disable runs on the processor to be shutdown.
*/
int __cpu_disable(void)
{
unsigned int cpu = smp_processor_id();
int ret;
ret = op_cpu_disable(cpu);
if (ret)
return ret;
remove_cpu_topology(cpu);
numa_remove_cpu(cpu);
/*
* Take this CPU offline. Once we clear this, we can't return,
* and we must not schedule until we're ready to give up the cpu.
*/
set_cpu_online(cpu, false);
ipi_teardown(cpu);
/*
* OK - migrate IRQs away from this CPU
*/
irq_migrate_all_off_this_cpu();
return 0;
}
static int op_cpu_kill(unsigned int cpu)
{
const struct cpu_operations *ops = get_cpu_ops(cpu);
/*
* If we have no means of synchronising with the dying CPU, then assume
* that it is really dead. We can only wait for an arbitrary length of
* time and hope that it's dead, so let's skip the wait and just hope.
*/
if (!ops->cpu_kill)
return 0;
return ops->cpu_kill(cpu);
}
/*
* Called on the thread which is asking for a CPU to be shutdown after the
* shutdown completed.
*/
void arch_cpuhp_cleanup_dead_cpu(unsigned int cpu)
{
int err;
pr_debug("CPU%u: shutdown\n", cpu);
/*
* Now that the dying CPU is beyond the point of no return w.r.t.
* in-kernel synchronisation, try to get the firwmare to help us to
* verify that it has really left the kernel before we consider
* clobbering anything it might still be using.
*/
err = op_cpu_kill(cpu);
if (err)
pr_warn("CPU%d may not have shut down cleanly: %d\n", cpu, err);
}
/*
* Called from the idle thread for the CPU which has been shutdown.
*
*/
void __noreturn cpu_die(void)
{
unsigned int cpu = smp_processor_id();
const struct cpu_operations *ops = get_cpu_ops(cpu);
idle_task_exit();
local_daif_mask();
/* Tell cpuhp_bp_sync_dead() that this CPU is now safe to dispose of */
cpuhp_ap_report_dead();
/*
* Actually shutdown the CPU. This must never fail. The specific hotplug
* mechanism must perform all required cache maintenance to ensure that
* no dirty lines are lost in the process of shutting down the CPU.
*/
ops->cpu_die(cpu);
BUG();
}
#endif
static void __cpu_try_die(int cpu)
{
#ifdef CONFIG_HOTPLUG_CPU
const struct cpu_operations *ops = get_cpu_ops(cpu);
if (ops && ops->cpu_die)
ops->cpu_die(cpu);
#endif
}
/*
* Kill the calling secondary CPU, early in bringup before it is turned
* online.
*/
void __noreturn cpu_die_early(void)
{
int cpu = smp_processor_id();
pr_crit("CPU%d: will not boot\n", cpu);
/* Mark this CPU absent */
set_cpu_present(cpu, 0);
rcutree_report_cpu_dead();
if (IS_ENABLED(CONFIG_HOTPLUG_CPU)) {
update_cpu_boot_status(CPU_KILL_ME);
__cpu_try_die(cpu);
}
update_cpu_boot_status(CPU_STUCK_IN_KERNEL);
cpu_park_loop();
}
static void __init hyp_mode_check(void)
{
if (is_hyp_mode_available())
pr_info("CPU: All CPU(s) started at EL2\n");
else if (is_hyp_mode_mismatched())
WARN_TAINT(1, TAINT_CPU_OUT_OF_SPEC,
"CPU: CPUs started in inconsistent modes");
else
pr_info("CPU: All CPU(s) started at EL1\n");
if (IS_ENABLED(CONFIG_KVM) && !is_kernel_in_hyp_mode()) {
kvm_compute_layout();
kvm_apply_hyp_relocations();
}
}
void __init smp_cpus_done(unsigned int max_cpus)
{
pr_info("SMP: Total of %d processors activated.\n", num_online_cpus());
hyp_mode_check();
setup_system_features();
setup_user_features();
mark_linear_text_alias_ro();
}
void __init smp_prepare_boot_cpu(void)
{
/*
* The runtime per-cpu areas have been allocated by
* setup_per_cpu_areas(), and CPU0's boot time per-cpu area will be
* freed shortly, so we must move over to the runtime per-cpu area.
*/
set_my_cpu_offset(per_cpu_offset(smp_processor_id()));
cpuinfo_store_boot_cpu();
setup_boot_cpu_features();
/* Conditionally switch to GIC PMR for interrupt masking */
if (system_uses_irq_prio_masking())
init_gic_priority_masking();
kasan_init_hw_tags();
/* Init percpu seeds for random tags after cpus are set up. */
kasan_init_sw_tags();
}
/*
* Duplicate MPIDRs are a recipe for disaster. Scan all initialized
* entries and check for duplicates. If any is found just ignore the
* cpu. cpu_logical_map was initialized to INVALID_HWID to avoid
* matching valid MPIDR values.
*/
static bool __init is_mpidr_duplicate(unsigned int cpu, u64 hwid)
{
unsigned int i;
for (i = 1; (i < cpu) && (i < NR_CPUS); i++)
if (cpu_logical_map(i) == hwid)
return true;
return false;
}
/*
* Initialize cpu operations for a logical cpu and
* set it in the possible mask on success
*/
static int __init smp_cpu_setup(int cpu)
{
const struct cpu_operations *ops;
if (init_cpu_ops(cpu))
return -ENODEV;
ops = get_cpu_ops(cpu);
if (ops->cpu_init(cpu))
return -ENODEV;
set_cpu_possible(cpu, true);
return 0;
}
static bool bootcpu_valid __initdata;
static unsigned int cpu_count = 1;
int arch_register_cpu(int cpu)
{
acpi_handle acpi_handle = acpi_get_processor_handle(cpu);
struct cpu *c = &per_cpu(cpu_devices, cpu);
if (!acpi_disabled && !acpi_handle &&
IS_ENABLED(CONFIG_ACPI_HOTPLUG_CPU))
return -EPROBE_DEFER;
#ifdef CONFIG_ACPI_HOTPLUG_CPU
/* For now block anything that looks like physical CPU Hotplug */
if (invalid_logical_cpuid(cpu) || !cpu_present(cpu)) {
pr_err_once("Changing CPU present bit is not supported\n");
return -ENODEV;
}
#endif
/*
* Availability of the acpi handle is sufficient to establish
* that _STA has aleady been checked. No need to recheck here.
*/
c->hotpluggable = arch_cpu_is_hotpluggable(cpu);
return register_cpu(c, cpu);
}
#ifdef CONFIG_ACPI_HOTPLUG_CPU
void arch_unregister_cpu(int cpu)
{
acpi_handle acpi_handle = acpi_get_processor_handle(cpu);
struct cpu *c = &per_cpu(cpu_devices, cpu);
acpi_status status;
unsigned long long sta;
if (!acpi_handle) {
pr_err_once("Removing a CPU without associated ACPI handle\n");
return;
}
status = acpi_evaluate_integer(acpi_handle, "_STA", NULL, &sta);
if (ACPI_FAILURE(status))
return;
/* For now do not allow anything that looks like physical CPU HP */
if (cpu_present(cpu) && !(sta & ACPI_STA_DEVICE_PRESENT)) {
pr_err_once("Changing CPU present bit is not supported\n");
return;
}
unregister_cpu(c);
}
#endif /* CONFIG_ACPI_HOTPLUG_CPU */
#ifdef CONFIG_ACPI
static struct acpi_madt_generic_interrupt cpu_madt_gicc[NR_CPUS];
struct acpi_madt_generic_interrupt *acpi_cpu_get_madt_gicc(int cpu)
{
return &cpu_madt_gicc[cpu];
}
EXPORT_SYMBOL_GPL(acpi_cpu_get_madt_gicc);
/*
* acpi_map_gic_cpu_interface - parse processor MADT entry
*
* Carry out sanity checks on MADT processor entry and initialize
* cpu_logical_map on success
*/
static void __init
acpi_map_gic_cpu_interface(struct acpi_madt_generic_interrupt *processor)
{
u64 hwid = processor->arm_mpidr;
if (!(processor->flags &
(ACPI_MADT_ENABLED | ACPI_MADT_GICC_ONLINE_CAPABLE))) {
pr_debug("skipping disabled CPU entry with 0x%llx MPIDR\n", hwid);
return;
}
if (hwid & ~MPIDR_HWID_BITMASK || hwid == INVALID_HWID) {
pr_err("skipping CPU entry with invalid MPIDR 0x%llx\n", hwid);
return;
}
if (is_mpidr_duplicate(cpu_count, hwid)) {
pr_err("duplicate CPU MPIDR 0x%llx in MADT\n", hwid);
return;
}
/* Check if GICC structure of boot CPU is available in the MADT */
if (cpu_logical_map(0) == hwid) {
if (bootcpu_valid) {
pr_err("duplicate boot CPU MPIDR: 0x%llx in MADT\n",
hwid);
return;
}
bootcpu_valid = true;
cpu_madt_gicc[0] = *processor;
return;
}
if (cpu_count >= NR_CPUS)
return;
/* map the logical cpu id to cpu MPIDR */
set_cpu_logical_map(cpu_count, hwid);
cpu_madt_gicc[cpu_count] = *processor;
/*
* Set-up the ACPI parking protocol cpu entries
* while initializing the cpu_logical_map to
* avoid parsing MADT entries multiple times for
* nothing (ie a valid cpu_logical_map entry should
* contain a valid parking protocol data set to
* initialize the cpu if the parking protocol is
* the only available enable method).
*/
acpi_set_mailbox_entry(cpu_count, processor);
cpu_count++;
}
static int __init
acpi_parse_gic_cpu_interface(union acpi_subtable_headers *header,
const unsigned long end)
{
struct acpi_madt_generic_interrupt *processor;
processor = (struct acpi_madt_generic_interrupt *)header;
if (BAD_MADT_GICC_ENTRY(processor, end))
return -EINVAL;
acpi_table_print_madt_entry(&header->common);
acpi_map_gic_cpu_interface(processor);
return 0;
}
static void __init acpi_parse_and_init_cpus(void)
{
int i;
/*
* do a walk of MADT to determine how many CPUs
* we have including disabled CPUs, and get information
* we need for SMP init.
*/
acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_INTERRUPT,
acpi_parse_gic_cpu_interface, 0);
/*
* In ACPI, SMP and CPU NUMA information is provided in separate
* static tables, namely the MADT and the SRAT.
*
* Thus, it is simpler to first create the cpu logical map through
* an MADT walk and then map the logical cpus to their node ids
* as separate steps.
*/
acpi_map_cpus_to_nodes();
for (i = 0; i < nr_cpu_ids; i++)
early_map_cpu_to_node(i, acpi_numa_get_nid(i));
}
#else
#define acpi_parse_and_init_cpus(...) do { } while (0)
#endif
/*
* Enumerate the possible CPU set from the device tree and build the
* cpu logical map array containing MPIDR values related to logical
* cpus. Assumes that cpu_logical_map(0) has already been initialized.
*/
static void __init of_parse_and_init_cpus(void)
{
struct device_node *dn;
for_each_of_cpu_node(dn) {
u64 hwid = of_get_cpu_hwid(dn, 0);
if (hwid & ~MPIDR_HWID_BITMASK)
goto next;
if (is_mpidr_duplicate(cpu_count, hwid)) {
pr_err("%pOF: duplicate cpu reg properties in the DT\n",
dn);
goto next;
}
/*
* The numbering scheme requires that the boot CPU
* must be assigned logical id 0. Record it so that
* the logical map built from DT is validated and can
* be used.
*/
if (hwid == cpu_logical_map(0)) {
if (bootcpu_valid) {
pr_err("%pOF: duplicate boot cpu reg property in DT\n",
dn);
goto next;
}
bootcpu_valid = true;
early_map_cpu_to_node(0, of_node_to_nid(dn));
/*
* cpu_logical_map has already been
* initialized and the boot cpu doesn't need
* the enable-method so continue without
* incrementing cpu.
*/
continue;
}
if (cpu_count >= NR_CPUS)
goto next;
pr_debug("cpu logical map 0x%llx\n", hwid);
set_cpu_logical_map(cpu_count, hwid);
early_map_cpu_to_node(cpu_count, of_node_to_nid(dn));
next:
cpu_count++;
}
}
/*
* Enumerate the possible CPU set from the device tree or ACPI and build the
* cpu logical map array containing MPIDR values related to logical
* cpus. Assumes that cpu_logical_map(0) has already been initialized.
*/
void __init smp_init_cpus(void)
{
int i;
if (acpi_disabled)
of_parse_and_init_cpus();
else
acpi_parse_and_init_cpus();
if (cpu_count > nr_cpu_ids)
pr_warn("Number of cores (%d) exceeds configured maximum of %u - clipping\n",
cpu_count, nr_cpu_ids);
if (!bootcpu_valid) {
pr_err("missing boot CPU MPIDR, not enabling secondaries\n");
return;
}
/*
* We need to set the cpu_logical_map entries before enabling
* the cpus so that cpu processor description entries (DT cpu nodes
* and ACPI MADT entries) can be retrieved by matching the cpu hwid
* with entries in cpu_logical_map while initializing the cpus.
* If the cpu set-up fails, invalidate the cpu_logical_map entry.
*/
for (i = 1; i < nr_cpu_ids; i++) {
if (cpu_logical_map(i) != INVALID_HWID) {
if (smp_cpu_setup(i))
set_cpu_logical_map(i, INVALID_HWID);
}
}
}
void __init smp_prepare_cpus(unsigned int max_cpus)
{
const struct cpu_operations *ops;
int err;
unsigned int cpu;
unsigned int this_cpu;
init_cpu_topology();
this_cpu = smp_processor_id();
store_cpu_topology(this_cpu);
numa_store_cpu_info(this_cpu);
numa_add_cpu(this_cpu);
/*
* If UP is mandated by "nosmp" (which implies "maxcpus=0"), don't set
* secondary CPUs present.
*/
if (max_cpus == 0)
return;
/*
* Initialise the present map (which describes the set of CPUs
* actually populated at the present time) and release the
* secondaries from the bootloader.
*/
for_each_possible_cpu(cpu) {
if (cpu == smp_processor_id())
continue;
ops = get_cpu_ops(cpu);
if (!ops)
continue;
err = ops->cpu_prepare(cpu);
if (err)
continue;
set_cpu_present(cpu, true);
numa_store_cpu_info(cpu);
}
}
static const char *ipi_types[MAX_IPI] __tracepoint_string = {
[IPI_RESCHEDULE] = "Rescheduling interrupts",
[IPI_CALL_FUNC] = "Function call interrupts",
[IPI_CPU_STOP] = "CPU stop interrupts",
[IPI_CPU_STOP_NMI] = "CPU stop NMIs",
[IPI_TIMER] = "Timer broadcast interrupts",
[IPI_IRQ_WORK] = "IRQ work interrupts",
[IPI_CPU_BACKTRACE] = "CPU backtrace interrupts",
[IPI_KGDB_ROUNDUP] = "KGDB roundup interrupts",
};
static void smp_cross_call(const struct cpumask *target, unsigned int ipinr);
unsigned long irq_err_count;
int arch_show_interrupts(struct seq_file *p, int prec)
{
unsigned int cpu, i;
for (i = 0; i < MAX_IPI; i++) {
seq_printf(p, "%*s%u:%s", prec - 1, "IPI", i,
prec >= 4 ? " " : "");
for_each_online_cpu(cpu)
seq_printf(p, "%10u ", irq_desc_kstat_cpu(ipi_desc[i], cpu));
seq_printf(p, " %s\n", ipi_types[i]);
}
seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
return 0;
}
void arch_send_call_function_ipi_mask(const struct cpumask *mask)
{
smp_cross_call(mask, IPI_CALL_FUNC);
}
void arch_send_call_function_single_ipi(int cpu)
{
smp_cross_call(cpumask_of(cpu), IPI_CALL_FUNC);
}
#ifdef CONFIG_IRQ_WORK
void arch_irq_work_raise(void)
{
smp_cross_call(cpumask_of(smp_processor_id()), IPI_IRQ_WORK);
}
#endif
static void __noreturn local_cpu_stop(unsigned int cpu)
{
set_cpu_online(cpu, false);
local_daif_mask();
sdei_mask_local_cpu();
cpu_park_loop();
}
/*
* We need to implement panic_smp_self_stop() for parallel panic() calls, so
* that cpu_online_mask gets correctly updated and smp_send_stop() can skip
* CPUs that have already stopped themselves.
*/
void __noreturn panic_smp_self_stop(void)
{
local_cpu_stop(smp_processor_id());
}
static void __noreturn ipi_cpu_crash_stop(unsigned int cpu, struct pt_regs *regs)
{
#ifdef CONFIG_KEXEC_CORE
/*
* Use local_daif_mask() instead of local_irq_disable() to make sure
* that pseudo-NMIs are disabled. The "crash stop" code starts with
* an IRQ and falls back to NMI (which might be pseudo). If the IRQ
* finally goes through right as we're timing out then the NMI could
* interrupt us. It's better to prevent the NMI and let the IRQ
* finish since the pt_regs will be better.
*/
local_daif_mask();
crash_save_cpu(regs, cpu);
set_cpu_online(cpu, false);
sdei_mask_local_cpu();
if (IS_ENABLED(CONFIG_HOTPLUG_CPU))
__cpu_try_die(cpu);
/* just in case */
cpu_park_loop();
#else
BUG();
#endif
}
static void arm64_backtrace_ipi(cpumask_t *mask)
{
__ipi_send_mask(ipi_desc[IPI_CPU_BACKTRACE], mask);
}
void arch_trigger_cpumask_backtrace(const cpumask_t *mask, int exclude_cpu)
{
/*
* NOTE: though nmi_trigger_cpumask_backtrace() has "nmi_" in the name,
* nothing about it truly needs to be implemented using an NMI, it's
* just that it's _allowed_ to work with NMIs. If ipi_should_be_nmi()
* returned false our backtrace attempt will just use a regular IPI.
*/
nmi_trigger_cpumask_backtrace(mask, exclude_cpu, arm64_backtrace_ipi);
}
#ifdef CONFIG_KGDB
void kgdb_roundup_cpus(void)
{
int this_cpu = raw_smp_processor_id();
int cpu;
for_each_online_cpu(cpu) {
/* No need to roundup ourselves */
if (cpu == this_cpu)
continue;
__ipi_send_single(ipi_desc[IPI_KGDB_ROUNDUP], cpu);
}
}
#endif
/*
* Main handler for inter-processor interrupts
*/
static void do_handle_IPI(int ipinr)
{
unsigned int cpu = smp_processor_id();
if ((unsigned)ipinr < NR_IPI)
trace_ipi_entry(ipi_types[ipinr]);
switch (ipinr) {
case IPI_RESCHEDULE:
scheduler_ipi();
break;
case IPI_CALL_FUNC:
generic_smp_call_function_interrupt();
break;
case IPI_CPU_STOP:
case IPI_CPU_STOP_NMI:
if (IS_ENABLED(CONFIG_KEXEC_CORE) && crash_stop) {
ipi_cpu_crash_stop(cpu, get_irq_regs());
unreachable();
} else {
local_cpu_stop(cpu);
}
break;
#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
case IPI_TIMER:
tick_receive_broadcast();
break;
#endif
#ifdef CONFIG_IRQ_WORK
case IPI_IRQ_WORK:
irq_work_run();
break;
#endif
case IPI_CPU_BACKTRACE:
/*
* NOTE: in some cases this _won't_ be NMI context. See the
* comment in arch_trigger_cpumask_backtrace().
*/
nmi_cpu_backtrace(get_irq_regs());
break;
case IPI_KGDB_ROUNDUP:
kgdb_nmicallback(cpu, get_irq_regs());
break;
default:
pr_crit("CPU%u: Unknown IPI message 0x%x\n", cpu, ipinr);
break;
}
if ((unsigned)ipinr < NR_IPI)
trace_ipi_exit(ipi_types[ipinr]);
}
static irqreturn_t ipi_handler(int irq, void *data)
{
do_handle_IPI(irq - ipi_irq_base);
return IRQ_HANDLED;
}
static void smp_cross_call(const struct cpumask *target, unsigned int ipinr)
{
trace_ipi_raise(target, ipi_types[ipinr]);
__ipi_send_mask(ipi_desc[ipinr], target);
}
static bool ipi_should_be_nmi(enum ipi_msg_type ipi)
{
if (!system_uses_irq_prio_masking())
return false;
switch (ipi) {
case IPI_CPU_STOP_NMI:
case IPI_CPU_BACKTRACE:
case IPI_KGDB_ROUNDUP:
return true;
default:
return false;
}
}
static void ipi_setup(int cpu)
{
int i;
if (WARN_ON_ONCE(!ipi_irq_base))
return;
for (i = 0; i < nr_ipi; i++) {
if (ipi_should_be_nmi(i)) {
prepare_percpu_nmi(ipi_irq_base + i);
enable_percpu_nmi(ipi_irq_base + i, 0);
} else {
enable_percpu_irq(ipi_irq_base + i, 0);
}
}
}
#ifdef CONFIG_HOTPLUG_CPU
static void ipi_teardown(int cpu)
{
int i;
if (WARN_ON_ONCE(!ipi_irq_base))
return;
for (i = 0; i < nr_ipi; i++) {
if (ipi_should_be_nmi(i)) {
disable_percpu_nmi(ipi_irq_base + i);
teardown_percpu_nmi(ipi_irq_base + i);
} else {
disable_percpu_irq(ipi_irq_base + i);
}
}
}
#endif
void __init set_smp_ipi_range(int ipi_base, int n)
{
int i;
WARN_ON(n < MAX_IPI);
nr_ipi = min(n, MAX_IPI);
for (i = 0; i < nr_ipi; i++) {
int err;
if (ipi_should_be_nmi(i)) {
err = request_percpu_nmi(ipi_base + i, ipi_handler,
"IPI", &irq_stat);
WARN(err, "Could not request IPI %d as NMI, err=%d\n",
i, err);
} else {
err = request_percpu_irq(ipi_base + i, ipi_handler,
"IPI", &irq_stat);
WARN(err, "Could not request IPI %d as IRQ, err=%d\n",
i, err);
}
ipi_desc[i] = irq_to_desc(ipi_base + i);
irq_set_status_flags(ipi_base + i, IRQ_HIDDEN);
}
ipi_irq_base = ipi_base;
/* Setup the boot CPU immediately */
ipi_setup(smp_processor_id());
}
void arch_smp_send_reschedule(int cpu)
{
smp_cross_call(cpumask_of(cpu), IPI_RESCHEDULE);
}
#ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
void arch_send_wakeup_ipi(unsigned int cpu)
{
/*
* We use a scheduler IPI to wake the CPU as this avoids the need for a
* dedicated IPI and we can safely handle spurious scheduler IPIs.
*/
smp_send_reschedule(cpu);
}
#endif
#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
void tick_broadcast(const struct cpumask *mask)
{
smp_cross_call(mask, IPI_TIMER);
}
#endif
/*
* The number of CPUs online, not counting this CPU (which may not be
* fully online and so not counted in num_online_cpus()).
*/
static inline unsigned int num_other_online_cpus(void)
{
unsigned int this_cpu_online = cpu_online(smp_processor_id());
return num_online_cpus() - this_cpu_online;
}
void smp_send_stop(void)
{
static unsigned long stop_in_progress;
cpumask_t mask;
unsigned long timeout;
/*
* If this cpu is the only one alive at this point in time, online or
* not, there are no stop messages to be sent around, so just back out.
*/
if (num_other_online_cpus() == 0)
goto skip_ipi;
/* Only proceed if this is the first CPU to reach this code */
if (test_and_set_bit(0, &stop_in_progress))
return;
/*
* Send an IPI to all currently online CPUs except the CPU running
* this code.
*
* NOTE: we don't do anything here to prevent other CPUs from coming
* online after we snapshot `cpu_online_mask`. Ideally, the calling code
* should do something to prevent other CPUs from coming up. This code
* can be called in the panic path and thus it doesn't seem wise to
* grab the CPU hotplug mutex ourselves. Worst case:
* - If a CPU comes online as we're running, we'll likely notice it
* during the 1 second wait below and then we'll catch it when we try
* with an NMI (assuming NMIs are enabled) since we re-snapshot the
* mask before sending an NMI.
* - If we leave the function and see that CPUs are still online we'll
* at least print a warning. Especially without NMIs this function
* isn't foolproof anyway so calling code will just have to accept
* the fact that there could be cases where a CPU can't be stopped.
*/
cpumask_copy(&mask, cpu_online_mask);
cpumask_clear_cpu(smp_processor_id(), &mask);
if (system_state <= SYSTEM_RUNNING)
pr_crit("SMP: stopping secondary CPUs\n");
/*
* Start with a normal IPI and wait up to one second for other CPUs to
* stop. We do this first because it gives other processors a chance
* to exit critical sections / drop locks and makes the rest of the
* stop process (especially console flush) more robust.
*/
smp_cross_call(&mask, IPI_CPU_STOP);
timeout = USEC_PER_SEC;
while (num_other_online_cpus() && timeout--)
udelay(1);
/*
* If CPUs are still online, try an NMI. There's no excuse for this to
* be slow, so we only give them an extra 10 ms to respond.
*/
if (num_other_online_cpus() && ipi_should_be_nmi(IPI_CPU_STOP_NMI)) {
smp_rmb();
cpumask_copy(&mask, cpu_online_mask);
cpumask_clear_cpu(smp_processor_id(), &mask);
pr_info("SMP: retry stop with NMI for CPUs %*pbl\n",
cpumask_pr_args(&mask));
smp_cross_call(&mask, IPI_CPU_STOP_NMI);
timeout = USEC_PER_MSEC * 10;
while (num_other_online_cpus() && timeout--)
udelay(1);
}
if (num_other_online_cpus()) {
smp_rmb();
cpumask_copy(&mask, cpu_online_mask);
cpumask_clear_cpu(smp_processor_id(), &mask);
pr_warn("SMP: failed to stop secondary CPUs %*pbl\n",
cpumask_pr_args(&mask));
}
skip_ipi:
sdei_mask_local_cpu();
}
#ifdef CONFIG_KEXEC_CORE
void crash_smp_send_stop(void)
{
/*
* This function can be called twice in panic path, but obviously
* we execute this only once.
*
* We use this same boolean to tell whether the IPI we send was a
* stop or a "crash stop".
*/
if (crash_stop)
return;
crash_stop = 1;
smp_send_stop();
sdei_handler_abort();
}
bool smp_crash_stop_failed(void)
{
return num_other_online_cpus() != 0;
}
#endif
static bool have_cpu_die(void)
{
#ifdef CONFIG_HOTPLUG_CPU
int any_cpu = raw_smp_processor_id();
const struct cpu_operations *ops = get_cpu_ops(any_cpu);
if (ops && ops->cpu_die)
return true;
#endif
return false;
}
bool cpus_are_stuck_in_kernel(void)
{
bool smp_spin_tables = (num_possible_cpus() > 1 && !have_cpu_die());
return !!cpus_stuck_in_kernel || smp_spin_tables ||
is_protected_kvm_enabled();
}