[PATCH 12/20] net/iucv: Convert to hotplug state machine
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: 2016-11-17 18:36:33
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 <redacted> Cc: "David S. Miller" <davem@davemloft.net> Cc: linux-s390@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> --- 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