[PATCH 12/20] net/iucv: Convert to hotplug state machine
From: Sebastian Andrzej Siewior
Date: Thu Nov 17 2016 - 13:36:36 EST
Install the callbacks via the state machine and let the core invoke the
callbacks on the already online CPUs. The smp function calls in the
online/downprep callbacks are not required as the callback is guaranteed to
be invoked on the upcoming/outgoing cpu.
Cc: Ursula Braun <ubraun@xxxxxxxxxxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: linux-s390@xxxxxxxxxxxxxxx
Cc: netdev@xxxxxxxxxxxxxxx
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
---
include/linux/cpuhotplug.h | 1 +
net/iucv/iucv.c | 118 +++++++++++++++++----------------------------
2 files changed, 45 insertions(+), 74 deletions(-)
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index fd5598b8353a..69abf2c09f6c 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -63,6 +63,7 @@ enum cpuhp_state {
CPUHP_X86_THERM_PREPARE,
CPUHP_X86_CPUID_PREPARE,
CPUHP_X86_MSR_PREPARE,
+ CPUHP_NET_IUCV_PREPARE,
CPUHP_TIMERS_DEAD,
CPUHP_NOTF_ERR_INJ_PREPARE,
CPUHP_MIPS_SOC_PREPARE,
diff --git a/net/iucv/iucv.c b/net/iucv/iucv.c
index 88a2a3ba4212..f0d6afc5d4a9 100644
--- a/net/iucv/iucv.c
+++ b/net/iucv/iucv.c
@@ -639,7 +639,7 @@ static void iucv_disable(void)
put_online_cpus();
}
-static void free_iucv_data(int cpu)
+static int iucv_cpu_dead(unsigned int cpu)
{
kfree(iucv_param_irq[cpu]);
iucv_param_irq[cpu] = NULL;
@@ -647,9 +647,10 @@ static void free_iucv_data(int cpu)
iucv_param[cpu] = NULL;
kfree(iucv_irq_data[cpu]);
iucv_irq_data[cpu] = NULL;
+ return 0;
}
-static int alloc_iucv_data(int cpu)
+static int iucv_cpu_prepare(unsigned int cpu)
{
/* Note: GFP_DMA used to get memory below 2G */
iucv_irq_data[cpu] = kmalloc_node(sizeof(struct iucv_irq_data),
@@ -671,58 +672,38 @@ static int alloc_iucv_data(int cpu)
return 0;
out_free:
- free_iucv_data(cpu);
+ iucv_cpu_dead(cpu);
return -ENOMEM;
}
-static int iucv_cpu_notify(struct notifier_block *self,
- unsigned long action, void *hcpu)
+static int iucv_cpu_online(unsigned int cpu)
{
- cpumask_t cpumask;
- long cpu = (long) hcpu;
-
- switch (action) {
- case CPU_UP_PREPARE:
- case CPU_UP_PREPARE_FROZEN:
- if (alloc_iucv_data(cpu))
- return notifier_from_errno(-ENOMEM);
- break;
- case CPU_UP_CANCELED:
- case CPU_UP_CANCELED_FROZEN:
- case CPU_DEAD:
- case CPU_DEAD_FROZEN:
- free_iucv_data(cpu);
- break;
- case CPU_ONLINE:
- case CPU_ONLINE_FROZEN:
- case CPU_DOWN_FAILED:
- case CPU_DOWN_FAILED_FROZEN:
- if (!iucv_path_table)
- break;
- smp_call_function_single(cpu, iucv_declare_cpu, NULL, 1);
- break;
- case CPU_DOWN_PREPARE:
- case CPU_DOWN_PREPARE_FROZEN:
- if (!iucv_path_table)
- break;
- cpumask_copy(&cpumask, &iucv_buffer_cpumask);
- cpumask_clear_cpu(cpu, &cpumask);
- if (cpumask_empty(&cpumask))
- /* Can't offline last IUCV enabled cpu. */
- return notifier_from_errno(-EINVAL);
- smp_call_function_single(cpu, iucv_retrieve_cpu, NULL, 1);
- if (cpumask_empty(&iucv_irq_cpumask))
- smp_call_function_single(
- cpumask_first(&iucv_buffer_cpumask),
- iucv_allow_cpu, NULL, 1);
- break;
- }
- return NOTIFY_OK;
+ if (!iucv_path_table)
+ return 0;
+ iucv_declare_cpu(NULL);
+ return 0;
}
-static struct notifier_block __refdata iucv_cpu_notifier = {
- .notifier_call = iucv_cpu_notify,
-};
+static int iucv_cpu_down_prep(unsigned int cpu)
+{
+ cpumask_t cpumask;
+
+ if (!iucv_path_table)
+ return 0;
+
+ cpumask_copy(&cpumask, &iucv_buffer_cpumask);
+ cpumask_clear_cpu(cpu, &cpumask);
+ if (cpumask_empty(&cpumask))
+ /* Can't offline last IUCV enabled cpu. */
+ return -EINVAL;
+
+ iucv_retrieve_cpu(NULL);
+ if (!cpumask_empty(&iucv_irq_cpumask))
+ return 0;
+ smp_call_function_single(cpumask_first(&iucv_buffer_cpumask),
+ iucv_allow_cpu, NULL, 1);
+ return 0;
+}
/**
* iucv_sever_pathid
@@ -2027,6 +2008,7 @@ struct iucv_interface iucv_if = {
};
EXPORT_SYMBOL(iucv_if);
+static enum cpuhp_state iucv_online;
/**
* iucv_init
*
@@ -2035,7 +2017,6 @@ EXPORT_SYMBOL(iucv_if);
static int __init iucv_init(void)
{
int rc;
- int cpu;
if (!MACHINE_IS_VM) {
rc = -EPROTONOSUPPORT;
@@ -2054,23 +2035,19 @@ static int __init iucv_init(void)
goto out_int;
}
- cpu_notifier_register_begin();
-
- for_each_online_cpu(cpu) {
- if (alloc_iucv_data(cpu)) {
- rc = -ENOMEM;
- goto out_free;
- }
- }
- rc = __register_hotcpu_notifier(&iucv_cpu_notifier);
+ rc = cpuhp_setup_state(CPUHP_NET_IUCV_PREPARE, "net/iucv:prepare",
+ iucv_cpu_prepare, iucv_cpu_dead);
if (rc)
goto out_free;
-
- cpu_notifier_register_done();
+ rc = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "net/iucv:online",
+ iucv_cpu_online, iucv_cpu_down_prep);
+ if (rc < 0)
+ goto out_free;
+ iucv_online = rc;
rc = register_reboot_notifier(&iucv_reboot_notifier);
if (rc)
- goto out_cpu;
+ goto out_free;
ASCEBC(iucv_error_no_listener, 16);
ASCEBC(iucv_error_no_memory, 16);
ASCEBC(iucv_error_pathid, 16);
@@ -2084,14 +2061,10 @@ static int __init iucv_init(void)
out_reboot:
unregister_reboot_notifier(&iucv_reboot_notifier);
-out_cpu:
- cpu_notifier_register_begin();
- __unregister_hotcpu_notifier(&iucv_cpu_notifier);
out_free:
- for_each_possible_cpu(cpu)
- free_iucv_data(cpu);
-
- cpu_notifier_register_done();
+ if (iucv_online)
+ cpuhp_remove_state(iucv_online);
+ cpuhp_remove_state(CPUHP_NET_IUCV_PREPARE);
root_device_unregister(iucv_root);
out_int:
@@ -2110,7 +2083,6 @@ static int __init iucv_init(void)
static void __exit iucv_exit(void)
{
struct iucv_irq_list *p, *n;
- int cpu;
spin_lock_irq(&iucv_queue_lock);
list_for_each_entry_safe(p, n, &iucv_task_queue, list)
@@ -2119,11 +2091,9 @@ static void __exit iucv_exit(void)
kfree(p);
spin_unlock_irq(&iucv_queue_lock);
unregister_reboot_notifier(&iucv_reboot_notifier);
- cpu_notifier_register_begin();
- __unregister_hotcpu_notifier(&iucv_cpu_notifier);
- for_each_possible_cpu(cpu)
- free_iucv_data(cpu);
- cpu_notifier_register_done();
+
+ cpuhp_remove_state_nocalls(iucv_online);
+ cpuhp_remove_state(CPUHP_NET_IUCV_PREPARE);
root_device_unregister(iucv_root);
bus_unregister(&iucv_bus);
unregister_external_irq(EXT_IRQ_IUCV, iucv_external_interrupt);
--
2.10.2