diff --git a/arch/arm/kernel/reboot.c b/arch/arm/kernel/reboot.c
index bb18ed0539f49261abd4b501cc7c32f443e5949b..0ce388f15422646023f64f7e888db942f1ddb5b0 100644
--- a/arch/arm/kernel/reboot.c
+++ b/arch/arm/kernel/reboot.c
@@ -88,11 +88,11 @@ void soft_restart(unsigned long addr)
* to execute e.g. a RAM-based pin loop is not sufficient. This allows the
* kexec'd kernel to use any and all RAM as it sees fit, without having to
* avoid any code or data used by any SW CPU pin loop. The CPU hotplug
- * functionality embodied in disable_nonboot_cpus() to achieve this.
+ * functionality embodied in smp_shutdown_nonboot_cpus() to achieve this.
*/
void machine_shutdown(void)
{
- disable_nonboot_cpus();
+ smp_shutdown_nonboot_cpus(reboot_cpu);
}
/*
diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c
index 590963c9c6094435c1bd5bbe599327f7f1264e94..5b73e92c99e353bf3ba52a2fe26b8724c9b0c10d 100644
--- a/arch/arm64/kernel/hibernate.c
+++ b/arch/arm64/kernel/hibernate.c
@@ -166,14 +166,11 @@ int arch_hibernation_header_restore(void *addr)
sleep_cpu = -EINVAL;
return -EINVAL;
}
- if (!cpu_online(sleep_cpu)) {
- pr_info("Hibernated on a CPU that is offline! Bringing CPU up.\n");
- ret = cpu_up(sleep_cpu);
- if (ret) {
- pr_err("Failed to bring hibernate-CPU up!\n");
- sleep_cpu = -EINVAL;
- return ret;
- }
+
+ ret = bringup_hibernate_cpu(sleep_cpu);
+ if (ret) {
+ sleep_cpu = -EINVAL;
+ return ret;
}
resume_hdr = *hdr;
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 00626057a384a5c38330f20d0c5d11148c4f3fd2..3e5a6ad66cbea155b9f3a68478d81c6ceb7a958c 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -141,11 +141,11 @@ void arch_cpu_idle_dead(void)
* to execute e.g. a RAM-based pin loop is not sufficient. This allows the
* kexec'd kernel to use any and all RAM as it sees fit, without having to
* avoid any code or data used by any SW CPU pin loop. The CPU hotplug
- * functionality embodied in disable_nonboot_cpus() to achieve this.
+ * functionality embodied in smpt_shutdown_nonboot_cpus() to achieve this.
*/
void machine_shutdown(void)
{
- disable_nonboot_cpus();
+ smp_shutdown_nonboot_cpus(reboot_cpu);
}
/*
diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c
index 743aaf5283278af5a12d21f449e8ec957a4096e8..10cb9382ab76c47cb9381d62bc30283041f82dd2 100644
--- a/arch/ia64/kernel/process.c
+++ b/arch/ia64/kernel/process.c
@@ -646,14 +646,8 @@ cpu_halt (void)
void machine_shutdown(void)
{
-#ifdef CONFIG_HOTPLUG_CPU
- int cpu;
+ smp_shutdown_nonboot_cpus(reboot_cpu);
- for_each_online_cpu(cpu) {
- if (cpu != smp_processor_id())
- cpu_down(cpu);
- }
-#endif
#ifdef CONFIG_KEXEC
kexec_disable_iosapic();
#endif
diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
index f510c00bda8820077b40effd377f2799b68828b9..0def6242b3eab7639808f7bc2b13c136531a4771 100644
--- a/arch/mips/kernel/smp.c
+++ b/arch/mips/kernel/smp.c
@@ -696,29 +696,22 @@ 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);
+ 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)
diff --git a/arch/parisc/kernel/processor.c b/arch/parisc/kernel/processor.c
index 13f771f74ee3bce3857cf2d9c3088d8e7243929b..7f2d0c0ecc804188e0c2e4abc2007ce1472d0668 100644
--- a/arch/parisc/kernel/processor.c
+++ b/arch/parisc/kernel/processor.c
@@ -212,7 +212,7 @@ static int __init processor_probe(struct parisc_device *dev)
#ifdef CONFIG_SMP
if (cpuid) {
set_cpu_present(cpuid, true);
- cpu_up(cpuid);
+ add_cpu(cpuid);
}
#endif
diff --git a/arch/powerpc/kexec/core_64.c b/arch/powerpc/kexec/core_64.c
index 04a7cba58eff4fc13a13030400a57176776fdbf7..b4184092172a6d3767054c80ff695d16cb53534e 100644
--- a/arch/powerpc/kexec/core_64.c
+++ b/arch/powerpc/kexec/core_64.c
@@ -212,7 +212,7 @@ static void wake_offline_cpus(void)
if (!cpu_online(cpu)) {
printk(KERN_INFO "kexec: Waking offline cpu %d.\n",
cpu);
- WARN_ON(cpu_up(cpu));
+ WARN_ON(add_cpu(cpu));
}
}
}
diff --git a/arch/sparc/kernel/ds.c b/arch/sparc/kernel/ds.c
index bbf59b3b4af86c9c674574c78e1576d310bc5f66..75232cbd58bf520695fb1509397419520ae6d13e 100644
--- a/arch/sparc/kernel/ds.c
+++ b/arch/sparc/kernel/ds.c
@@ -555,7 +555,7 @@ static int dr_cpu_configure(struct ds_info *dp, struct ds_cap_state *cp,
printk(KERN_INFO "ds-%llu: Starting cpu %d...\n",
dp->id, cpu);
- err = cpu_up(cpu);
+ err = add_cpu(cpu);
if (err) {
__u32 res = DR_CPU_RES_FAILURE;
__u32 stat = DR_CPU_STAT_UNCONFIGURED;
@@ -611,7 +611,7 @@ static int dr_cpu_unconfigure(struct ds_info *dp,
printk(KERN_INFO "ds-%llu: Shutting down cpu %d...\n",
dp->id, cpu);
- err = cpu_down(cpu);
+ err = remove_cpu(cpu);
if (err)
dr_cpu_mark(resp, cpu, ncpus,
DR_CPU_RES_FAILURE,
diff --git a/arch/x86/kernel/topology.c b/arch/x86/kernel/topology.c
index be5bc2e47c71e864a0500a9ad64d81247bf8782e..b8810ebbc8ae78c16be71254ca75c47814386c8a 100644
--- a/arch/x86/kernel/topology.c
+++ b/arch/x86/kernel/topology.c
@@ -59,39 +59,29 @@ __setup("cpu0_hotplug", enable_cpu0_hotplug);
*/
int _debug_hotplug_cpu(int cpu, int action)
{
- struct device *dev = get_cpu_device(cpu);
int ret;
if (!cpu_is_hotpluggable(cpu))
return -EINVAL;
- lock_device_hotplug();
-
switch (action) {
case 0:
- ret = cpu_down(cpu);
- if (!ret) {
+ ret = remove_cpu(cpu);
+ if (!ret)
pr_info("DEBUG_HOTPLUG_CPU0: CPU %u is now offline\n", cpu);
- dev->offline = true;
- kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
- } else
+ else
pr_debug("Can't offline CPU%d.\n", cpu);
break;
case 1:
- ret = cpu_up(cpu);
- if (!ret) {
- dev->offline = false;
- kobject_uevent(&dev->kobj, KOBJ_ONLINE);
- } else {
+ ret = add_cpu(cpu);
+ if (ret)
pr_debug("Can't online CPU%d.\n", cpu);
- }
+
break;
default:
ret = -EINVAL;
}
- unlock_device_hotplug();
-
return ret;
}
diff --git a/arch/x86/mm/mmio-mod.c b/arch/x86/mm/mmio-mod.c
index 673de60633459309557508af9700bc13c24e9d52..109325d77b3e8f0cef8c77d6466965a70cc896fa 100644
--- a/arch/x86/mm/mmio-mod.c
+++ b/arch/x86/mm/mmio-mod.c
@@ -386,7 +386,7 @@ static void enter_uniprocessor(void)
put_online_cpus();
for_each_cpu(cpu, downed_cpus) {
- err = cpu_down(cpu);
+ err = remove_cpu(cpu);
if (!err)
pr_info("CPU%d is down.\n", cpu);
else
@@ -406,7 +406,7 @@ static void leave_uniprocessor(void)
return;
pr_notice("Re-enabling CPUs...\n");
for_each_cpu(cpu, downed_cpus) {
- err = cpu_up(cpu);
+ err = add_cpu(cpu);
if (!err)
pr_info("enabled CPU%d.\n", cpu);
else
diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index 7a43b2ae19f1228b247e57fe453d21ab15e116f7..2097fa0ebdb59bf6a9e42f352751e0f4dd7fd558 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -132,7 +132,7 @@ void __init xen_smp_cpus_done(unsigned int max_cpus)
if (xen_vcpu_nr(cpu) < MAX_VIRT_CPUS)
continue;
- rc = cpu_down(cpu);
+ rc = remove_cpu(cpu);
if (rc == 0) {
/*
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index df19c002d747323bce1f6b0f057e8b698750edbd..9a1c00fbbaefc57c21f975fe9f09161e076569cc 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -55,7 +55,7 @@ static int cpu_subsys_online(struct device *dev)
if (from_nid == NUMA_NO_NODE)
return -ENODEV;
- ret = cpu_up(cpuid);
+ ret = cpu_device_up(dev);
/*
* When hot adding memory to memoryless node and enabling a cpu
* on the node, node number of the cpu may internally change.
@@ -69,7 +69,7 @@ static int cpu_subsys_online(struct device *dev)
static int cpu_subsys_offline(struct device *dev)
{
- return cpu_down(dev->id);
+ return cpu_device_down(dev);
}
void unregister_cpu(struct cpu *cpu)
diff --git a/drivers/firmware/psci/psci_checker.c b/drivers/firmware/psci/psci_checker.c
index 6a445397771ca027841e82b6ab93f48db877ef28..873841af8d5758b34c2369269985dee7df290322 100644
--- a/drivers/firmware/psci/psci_checker.c
+++ b/drivers/firmware/psci/psci_checker.c
@@ -84,7 +84,7 @@ static unsigned int down_and_up_cpus(const struct cpumask *cpus,
/* Try to power down all CPUs in the mask. */
for_each_cpu(cpu, cpus) {
- int ret = cpu_down(cpu);
+ int ret = remove_cpu(cpu);
/*
* cpu_down() checks the number of online CPUs before the TOS
@@ -116,7 +116,7 @@ static unsigned int down_and_up_cpus(const struct cpumask *cpus,
/* Try to power up all the CPUs that have been offlined. */
for_each_cpu(cpu, offlined_cpus) {
- int ret = cpu_up(cpu);
+ int ret = add_cpu(cpu);
if (ret != 0) {
pr_err("Error occurred (%d) while trying "
diff --git a/drivers/xen/cpu_hotplug.c b/drivers/xen/cpu_hotplug.c
index f192b6f42da9f7eb856c34f2baac0a6a7a4c4c45..ec975decb5def48fd163af76f7560e9cb6ff2b5f 100644
--- a/drivers/xen/cpu_hotplug.c
+++ b/drivers/xen/cpu_hotplug.c
@@ -94,7 +94,7 @@ static int setup_cpu_watcher(struct notifier_block *notifier,
for_each_possible_cpu(cpu) {
if (vcpu_online(cpu) == 0) {
- (void)cpu_down(cpu);
+ device_offline(get_cpu_device(cpu));
set_cpu_present(cpu, false);
}
}
diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index 1ca2baf817ed752da8e31bfd9906f99253a30672..beaed2dc269e8e4b955b66f8f82e28a9fa9bcffe 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -88,10 +88,13 @@ extern ssize_t arch_cpu_release(const char *, size_t);
#ifdef CONFIG_SMP
extern bool cpuhp_tasks_frozen;
-int cpu_up(unsigned int cpu);
+int add_cpu(unsigned int cpu);
+int cpu_device_up(struct device *dev);
void notify_cpu_starting(unsigned int cpu);
extern void cpu_maps_update_begin(void);
extern void cpu_maps_update_done(void);
+int bringup_hibernate_cpu(unsigned int sleep_cpu);
+void bringup_nonboot_cpus(unsigned int setup_max_cpus);
#else /* CONFIG_SMP */
#define cpuhp_tasks_frozen 0
@@ -117,7 +120,9 @@ extern void lockdep_assert_cpus_held(void);
extern void cpu_hotplug_disable(void);
extern void cpu_hotplug_enable(void);
void clear_tasks_mm_cpumask(int cpu);
-int cpu_down(unsigned int cpu);
+int remove_cpu(unsigned int cpu);
+int cpu_device_down(struct device *dev);
+extern void smp_shutdown_nonboot_cpus(unsigned int primary_cpu);
#else /* CONFIG_HOTPLUG_CPU */
@@ -129,6 +134,7 @@ static inline int cpus_read_trylock(void) { return true; }
static inline void lockdep_assert_cpus_held(void) { }
static inline void cpu_hotplug_disable(void) { }
static inline void cpu_hotplug_enable(void) { }
+static inline void smp_shutdown_nonboot_cpus(unsigned int primary_cpu) { }
#endif /* !CONFIG_HOTPLUG_CPU */
/* Wrappers which go away once all code is converted */
@@ -138,12 +144,18 @@ static inline void get_online_cpus(void) { cpus_read_lock(); }
static inline void put_online_cpus(void) { cpus_read_unlock(); }
#ifdef CONFIG_PM_SLEEP_SMP
-extern int freeze_secondary_cpus(int primary);
+int __freeze_secondary_cpus(int primary, bool suspend);
+static inline int freeze_secondary_cpus(int primary)
+{
+ return __freeze_secondary_cpus(primary, true);
+}
+
static inline int disable_nonboot_cpus(void)
{
- return freeze_secondary_cpus(0);
+ return __freeze_secondary_cpus(0, false);
}
-extern void enable_nonboot_cpus(void);
+
+void enable_nonboot_cpus(void);
static inline int suspend_disable_secondary_cpus(void)
{
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 221bf6a9e98a6ef0e1f3772b039c32a7d85ba944..2371292f30b03daa463706a2d9150c9c3bae5861 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -1041,7 +1041,7 @@ static int cpu_down_maps_locked(unsigned int cpu, enum cpuhp_state target)
return _cpu_down(cpu, 0, target);
}
-static int do_cpu_down(unsigned int cpu, enum cpuhp_state target)
+static int cpu_down(unsigned int cpu, enum cpuhp_state target)
{
int err;
@@ -1051,11 +1051,72 @@ static int do_cpu_down(unsigned int cpu, enum cpuhp_state target)
return err;
}
-int cpu_down(unsigned int cpu)
+/**
+ * cpu_device_down - Bring down a cpu device
+ * @dev: Pointer to the cpu device to offline
+ *
+ * This function is meant to be used by device core cpu subsystem only.
+ *
+ * Other subsystems should use remove_cpu() instead.
+ */
+int cpu_device_down(struct device *dev)
{
- return do_cpu_down(cpu, CPUHP_OFFLINE);
+ return cpu_down(dev->id, CPUHP_OFFLINE);
+}
+
+int remove_cpu(unsigned int cpu)
+{
+ int ret;
+
+ lock_device_hotplug();
+ ret = device_offline(get_cpu_device(cpu));
+ unlock_device_hotplug();
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(remove_cpu);
+
+void smp_shutdown_nonboot_cpus(unsigned int primary_cpu)
+{
+ unsigned int cpu;
+ int error;
+
+ cpu_maps_update_begin();
+
+ /*
+ * Make certain the cpu I'm about to reboot on is online.
+ *
+ * This is inline to what migrate_to_reboot_cpu() already do.
+ */
+ if (!cpu_online(primary_cpu))
+ primary_cpu = cpumask_first(cpu_online_mask);
+
+ for_each_online_cpu(cpu) {
+ if (cpu == primary_cpu)
+ continue;
+
+ error = cpu_down_maps_locked(cpu, CPUHP_OFFLINE);
+ if (error) {
+ pr_err("Failed to offline CPU%d - error=%d",
+ cpu, error);
+ break;
+ }
+ }
+
+ /*
+ * Ensure all but the reboot CPU are offline.
+ */
+ BUG_ON(num_online_cpus() > 1);
+
+ /*
+ * Make sure the CPUs won't be enabled by someone else after this
+ * point. Kexec will reboot to a new kernel shortly resetting
+ * everything along the way.
+ */
+ cpu_hotplug_disabled++;
+
+ cpu_maps_update_done();
}
-EXPORT_SYMBOL(cpu_down);
#else
#define takedown_cpu NULL
@@ -1124,8 +1185,8 @@ static int _cpu_up(unsigned int cpu, int tasks_frozen, enum cpuhp_state target)
}
/*
- * The caller of do_cpu_up might have raced with another
- * caller. Ignore it for now.
+ * The caller of cpu_up() might have raced with another
+ * caller. Nothing to do.
*/
if (st->state >= target)
goto out;
@@ -1169,7 +1230,7 @@ static int _cpu_up(unsigned int cpu, int tasks_frozen, enum cpuhp_state target)
return ret;
}
-static int do_cpu_up(unsigned int cpu, enum cpuhp_state target)
+static int cpu_up(unsigned int cpu, enum cpuhp_state target)
{
int err = 0;
@@ -1203,16 +1264,70 @@ static int do_cpu_up(unsigned int cpu, enum cpuhp_state target)
return err;
}
-int cpu_up(unsigned int cpu)
+/**
+ * cpu_device_up - Bring up a cpu device
+ * @dev: Pointer to the cpu device to online
+ *
+ * This function is meant to be used by device core cpu subsystem only.
+ *
+ * Other subsystems should use add_cpu() instead.
+ */
+int cpu_device_up(struct device *dev)
+{
+ return cpu_up(dev->id, CPUHP_ONLINE);
+}
+
+int add_cpu(unsigned int cpu)
+{
+ int ret;
+
+ lock_device_hotplug();
+ ret = device_online(get_cpu_device(cpu));
+ unlock_device_hotplug();
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(add_cpu);
+
+/**
+ * bringup_hibernate_cpu - Bring up the CPU that we hibernated on
+ * @sleep_cpu: The cpu we hibernated on and should be brought up.
+ *
+ * On some architectures like arm64, we can hibernate on any CPU, but on
+ * wake up the CPU we hibernated on might be offline as a side effect of
+ * using maxcpus= for example.
+ */
+int bringup_hibernate_cpu(unsigned int sleep_cpu)
{
- return do_cpu_up(cpu, CPUHP_ONLINE);
+ int ret;
+
+ if (!cpu_online(sleep_cpu)) {
+ pr_info("Hibernated on a CPU that is offline! Bringing CPU up.\n");
+ ret = cpu_up(sleep_cpu, CPUHP_ONLINE);
+ if (ret) {
+ pr_err("Failed to bring hibernate-CPU up!\n");
+ return ret;
+ }
+ }
+ return 0;
+}
+
+void bringup_nonboot_cpus(unsigned int setup_max_cpus)
+{
+ unsigned int cpu;
+
+ for_each_present_cpu(cpu) {
+ if (num_online_cpus() >= setup_max_cpus)
+ break;
+ if (!cpu_online(cpu))
+ cpu_up(cpu, CPUHP_ONLINE);
+ }
}
-EXPORT_SYMBOL_GPL(cpu_up);
#ifdef CONFIG_PM_SLEEP_SMP
static cpumask_var_t frozen_cpus;
-int freeze_secondary_cpus(int primary)
+int __freeze_secondary_cpus(int primary, bool suspend)
{
int cpu, error = 0;
@@ -1237,7 +1352,7 @@ int freeze_secondary_cpus(int primary)
if (cpu == primary)
continue;
- if (pm_wakeup_pending()) {
+ if (suspend && pm_wakeup_pending()) {
pr_info("Wakeup pending. Abort CPU freeze\n");
error = -EBUSY;
break;
@@ -2028,9 +2143,9 @@ static ssize_t write_cpuhp_target(struct device *dev,
goto out;
if (st->state < target)
- ret = do_cpu_up(dev->id, target);
+ ret = cpu_up(dev->id, target);
else
- ret = do_cpu_down(dev->id, target);
+ ret = cpu_down(dev->id, target);
out:
unlock_device_hotplug();
return ret ? ret : count;
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index c1f923d647ee13f02b4f66b4c9ab2adec06ac5e1..a2694ba82874b7c53fe520e48f4a4687735211e9 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -269,7 +269,6 @@ static void __hrtick_start(void *arg)
rq_lock(rq, &rf);
__hrtick_restart(rq);
- rq->hrtick_csd_pending = 0;
rq_unlock(rq, &rf);
}
@@ -293,12 +292,10 @@ void hrtick_start(struct rq *rq, u64 delay)
hrtimer_set_expires(timer, time);
- if (rq == this_rq()) {
+ if (rq == this_rq())
__hrtick_restart(rq);
- } else if (!rq->hrtick_csd_pending) {
+ else
smp_call_function_single_async(cpu_of(rq), &rq->hrtick_csd);
- rq->hrtick_csd_pending = 1;
- }
}
#else
@@ -322,8 +319,6 @@ void hrtick_start(struct rq *rq, u64 delay)
static void hrtick_rq_init(struct rq *rq)
{
#ifdef CONFIG_SMP
- rq->hrtick_csd_pending = 0;
-
rq->hrtick_csd.flags = 0;
rq->hrtick_csd.func = __hrtick_start;
rq->hrtick_csd.info = rq;
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 464742874be3e24df3d249a0cd52dd2f36806313..0f616bf7bce395217c3309c336732357e5d35572 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -992,7 +992,6 @@ struct rq {
#ifdef CONFIG_SCHED_HRTICK
#ifdef CONFIG_SMP
- int hrtick_csd_pending;
call_single_data_t hrtick_csd;
#endif
struct hrtimer hrtick_timer;
diff --git a/kernel/smp.c b/kernel/smp.c
index d0ada39eb4d41bb4a246d28bec3f7ed4ba9d8c2a..786092aabdcd6a997f1bbf428aba111421110bea 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -329,6 +329,11 @@ EXPORT_SYMBOL(smp_call_function_single);
* (ie: embedded in an object) and is responsible for synchronizing it
* such that the IPIs performed on the @csd are strictly serialized.
*
+ * If the function is called with one csd which has not yet been
+ * processed by previous call to smp_call_function_single_async(), the
+ * function will return immediately with -EBUSY showing that the csd
+ * object is still in progress.
+ *
* NOTE: Be careful, there is unfortunately no current debugging facility to
* validate the correctness of this serialization.
*/
@@ -338,14 +343,17 @@ int smp_call_function_single_async(int cpu, call_single_data_t *csd)
preempt_disable();
- /* We could deadlock if we have to wait here with interrupts disabled! */
- if (WARN_ON_ONCE(csd->flags & CSD_FLAG_LOCK))
- csd_lock_wait(csd);
+ if (csd->flags & CSD_FLAG_LOCK) {
+ err = -EBUSY;
+ goto out;
+ }
csd->flags = CSD_FLAG_LOCK;
smp_wmb();
err = generic_exec_single(cpu, csd, csd->func, csd->info);
+
+out:
preempt_enable();
return err;
@@ -589,20 +597,13 @@ void __init setup_nr_cpu_ids(void)
void __init smp_init(void)
{
int num_nodes, num_cpus;
- unsigned int cpu;
idle_threads_init();
cpuhp_threads_init();
pr_info("Bringing up secondary CPUs ...\n");
- /* FIXME: This should be done in userspace --RR */
- for_each_present_cpu(cpu) {
- if (num_online_cpus() >= setup_max_cpus)
- break;
- if (!cpu_online(cpu))
- cpu_up(cpu);
- }
+ bringup_nonboot_cpus(setup_max_cpus);
num_nodes = num_online_nodes();
num_cpus = num_online_cpus();
diff --git a/kernel/torture.c b/kernel/torture.c
index 8683375dc0c7488ef59da4d3413cb64f060c8088..a1a41484ff6d6688bef6def0974d9df9d020b278 100644
--- a/kernel/torture.c
+++ b/kernel/torture.c
@@ -101,7 +101,7 @@ bool torture_offline(int cpu, long *n_offl_attempts, long *n_offl_successes,
torture_type, cpu);
starttime = jiffies;
(*n_offl_attempts)++;
- ret = cpu_down(cpu);
+ ret = remove_cpu(cpu);
if (ret) {
s = "";
if (!rcu_inkernel_boot_has_ended() && ret == -EBUSY) {
@@ -159,7 +159,7 @@ bool torture_online(int cpu, long *n_onl_attempts, long *n_onl_successes,
torture_type, cpu);
starttime = jiffies;
(*n_onl_attempts)++;
- ret = cpu_up(cpu);
+ ret = add_cpu(cpu);
if (ret) {
s = "";
if (!rcu_inkernel_boot_has_ended() && ret == -EBUSY) {
@@ -209,17 +209,18 @@ torture_onoff(void *arg)
for_each_online_cpu(cpu)
maxcpu = cpu;
WARN_ON(maxcpu < 0);
- if (!IS_MODULE(CONFIG_TORTURE_TEST))
+ if (!IS_MODULE(CONFIG_TORTURE_TEST)) {
for_each_possible_cpu(cpu) {
if (cpu_online(cpu))
continue;
- ret = cpu_up(cpu);
+ ret = add_cpu(cpu);
if (ret && verbose) {
pr_alert("%s" TORTURE_FLAG
"%s: Initial online %d: errno %d\n",
__func__, torture_type, cpu, ret);
}
}
+ }
if (maxcpu == 0) {
VERBOSE_TOROUT_STRING("Only one CPU, so CPU-hotplug testing is disabled");