The driver creates its own per-CPU threads which are updated based on
CPU hotplug events. It is also possible to delegate this task to the
smpboot-thread infrastructure and get the same job done while saving a
few lines of code.
The code checked ->iothread to decide if there is an active per-CPU
thread. With the smpboot infrastructure this is no longer possible and I
replaced its logic with the ->active member. The thread pointer is saved
in `kthread' instead of `iothread' so anything trying to use thread is
caught by the compiler.
The remaining part of the conversion is mostly straightforward.
This patch was only compile-tested due to -ENODEV.
Cc: qlogic-storage-upstr...@qlogic.com
Cc: "James E.J. Bottomley" <jbottom...@odin.com>
Cc: "Martin K. Petersen" <martin.peter...@oracle.com>
Cc: Christoph Hellwig <h...@lst.de>
Cc: linux-scsi@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bige...@linutronix.de>
---
drivers/scsi/bnx2fc/bnx2fc.h | 3 +-
drivers/scsi/bnx2fc/bnx2fc_fcoe.c | 187 ++++++++++++--------------------------
drivers/scsi/bnx2fc/bnx2fc_hwi.c | 4 +-
3 files changed, 64 insertions(+), 130 deletions(-)
diff --git a/drivers/scsi/bnx2fc/bnx2fc.h b/drivers/scsi/bnx2fc/bnx2fc.h
index 499e369eabf0..7bc5692bb493 100644
--- a/drivers/scsi/bnx2fc/bnx2fc.h
+++ b/drivers/scsi/bnx2fc/bnx2fc.h
@@ -168,9 +168,10 @@ extern struct fcoe_percpu_s bnx2fc_global;
extern struct workqueue_struct *bnx2fc_wq;
struct bnx2fc_percpu_s {
- struct task_struct *iothread;
+ struct task_struct *kthread;
struct list_head work_list;
spinlock_t fp_work_lock;
+ bool active;
};
struct bnx2fc_fw_stats {
diff --git a/drivers/scsi/bnx2fc/bnx2fc_fcoe.c
b/drivers/scsi/bnx2fc/bnx2fc_fcoe.c
index f5bc11b2e884..12ee035e9c4c 100644
--- a/drivers/scsi/bnx2fc/bnx2fc_fcoe.c
+++ b/drivers/scsi/bnx2fc/bnx2fc_fcoe.c
@@ -14,6 +14,7 @@
*/
#include "bnx2fc.h"
+#include <linux/smpboot.h>
static struct list_head adapter_list;
static struct list_head if_list;
@@ -98,13 +99,6 @@ static void __exit bnx2fc_mod_exit(void);
unsigned int bnx2fc_debug_level;
module_param_named(debug_logging, bnx2fc_debug_level, int, S_IRUGO|S_IWUSR);
-static int bnx2fc_cpu_callback(struct notifier_block *nfb,
- unsigned long action, void *hcpu);
-/* notification function for CPU hotplug events */
-static struct notifier_block bnx2fc_cpu_notifier = {
- .notifier_call = bnx2fc_cpu_callback,
-};
-
static inline struct net_device *bnx2fc_netdev(const struct fc_lport *lport)
{
return ((struct bnx2fc_interface *)
@@ -591,40 +585,26 @@ static void bnx2fc_recv_frame(struct sk_buff *skb)
fc_exch_recv(lport, fp);
}
-/**
- * bnx2fc_percpu_io_thread - thread per cpu for ios
- *
- * @arg: ptr to bnx2fc_percpu_info structure
- */
-int bnx2fc_percpu_io_thread(void *arg)
+static void bnx2fc_thread_io_process(unsigned int cpu)
{
- struct bnx2fc_percpu_s *p = arg;
+ struct bnx2fc_percpu_s *p = per_cpu_ptr(&bnx2fc_percpu, cpu);
struct bnx2fc_work *work, *tmp;
LIST_HEAD(work_list);
- set_user_nice(current, MIN_NICE);
- set_current_state(TASK_INTERRUPTIBLE);
- while (!kthread_should_stop()) {
- schedule();
- spin_lock_bh(&p->fp_work_lock);
- while (!list_empty(&p->work_list)) {
- list_splice_init(&p->work_list, &work_list);
- spin_unlock_bh(&p->fp_work_lock);
-
- list_for_each_entry_safe(work, tmp, &work_list, list) {
- list_del_init(&work->list);
- bnx2fc_process_cq_compl(work->tgt, work->wqe);
- kfree(work);
- }
-
- spin_lock_bh(&p->fp_work_lock);
- }
- __set_current_state(TASK_INTERRUPTIBLE);
+ spin_lock_bh(&p->fp_work_lock);
+ while (!list_empty(&p->work_list)) {
+ list_splice_init(&p->work_list, &work_list);
spin_unlock_bh(&p->fp_work_lock);
- }
- __set_current_state(TASK_RUNNING);
- return 0;
+ list_for_each_entry_safe(work, tmp, &work_list, list) {
+ list_del_init(&work->list);
+ bnx2fc_process_cq_compl(work->tgt, work->wqe);
+ kfree(work);
+ }
+
+ spin_lock_bh(&p->fp_work_lock);
+ }
+ spin_unlock_bh(&p->fp_work_lock);
}
static struct fc_host_statistics *bnx2fc_get_host_stats(struct Scsi_Host
*shost)
@@ -2518,34 +2498,9 @@ static struct fcoe_transport bnx2fc_transport = {
.disable = bnx2fc_disable,
};
-/**
- * bnx2fc_percpu_thread_create - Create a receive thread for an
- * online CPU
- *
- * @cpu: cpu index for the online cpu
- */
-static void bnx2fc_percpu_thread_create(unsigned int cpu)
+static void bnx2fc_thread_park(unsigned int cpu)
{
struct bnx2fc_percpu_s *p;
- struct task_struct *thread;
-
- p = &per_cpu(bnx2fc_percpu, cpu);
-
- thread = kthread_create_on_node(bnx2fc_percpu_io_thread,
- (void *)p, cpu_to_node(cpu),
- "bnx2fc_thread/%d", cpu);
- /* bind thread to the cpu */
- if (likely(!IS_ERR(thread))) {
- kthread_bind(thread, cpu);
- p->iothread = thread;
- wake_up_process(thread);
- }
-}
-
-static void bnx2fc_percpu_thread_destroy(unsigned int cpu)
-{
- struct bnx2fc_percpu_s *p;
- struct task_struct *thread;
struct bnx2fc_work *work, *tmp;
BNX2FC_MISC_DBG("destroying io thread for CPU %d\n", cpu);
@@ -2553,9 +2508,7 @@ static void bnx2fc_percpu_thread_destroy(unsigned int cpu)
/* Prevent any new work from being queued for this CPU */
p = &per_cpu(bnx2fc_percpu, cpu);
spin_lock_bh(&p->fp_work_lock);
- thread = p->iothread;
- p->iothread = NULL;
-
+ p->active = false;
/* Free all work in the list */
list_for_each_entry_safe(work, tmp, &p->work_list, list) {
@@ -2565,44 +2518,52 @@ static void bnx2fc_percpu_thread_destroy(unsigned int
cpu)
}
spin_unlock_bh(&p->fp_work_lock);
-
- if (thread)
- kthread_stop(thread);
}
-/**
- * bnx2fc_cpu_callback - Handler for CPU hotplug events
- *
- * @nfb: The callback data block
- * @action: The event triggering the callback
- * @hcpu: The index of the CPU that the event is for
- *
- * This creates or destroys per-CPU data for fcoe
- *
- * Returns NOTIFY_OK always.
- */
-static int bnx2fc_cpu_callback(struct notifier_block *nfb,
- unsigned long action, void *hcpu)
+static void bnx2fc_thread_cleanup(unsigned int cpu, bool online)
{
- unsigned cpu = (unsigned long)hcpu;
-
- switch (action) {
- case CPU_ONLINE:
- case CPU_ONLINE_FROZEN:
- printk(PFX "CPU %x online: Create Rx thread\n", cpu);
- bnx2fc_percpu_thread_create(cpu);
- break;
- case CPU_DEAD:
- case CPU_DEAD_FROZEN:
- printk(PFX "CPU %x offline: Remove Rx thread\n", cpu);
- bnx2fc_percpu_thread_destroy(cpu);
- break;
- default:
- break;
- }
- return NOTIFY_OK;
+ if (!online)
+ return;
+ bnx2fc_thread_park(cpu);
}
+static void bnx2fc_thread_setup(unsigned int cpu)
+{
+ struct bnx2fc_percpu_s *p = per_cpu_ptr(&bnx2fc_percpu, cpu);
+
+ set_user_nice(current, MIN_NICE);
+ INIT_LIST_HEAD(&p->work_list);
+ spin_lock_init(&p->fp_work_lock);
+}
+
+static int bnx2fc_thread_should_run(unsigned int cpu)
+{
+ struct bnx2fc_percpu_s *p = per_cpu_ptr(&bnx2fc_percpu, cpu);
+ /*
+ * lockless peek at the list. Real check is done in
+ * bnx2fc_thread_io_process()
+ */
+ return !list_empty(&p->work_list);
+}
+
+static void bnx2fc_thread_unpark(unsigned int cpu)
+{
+ struct bnx2fc_percpu_s *p = per_cpu_ptr(&bnx2fc_percpu, cpu);
+
+ p->active = true;
+}
+
+static struct smp_hotplug_thread bnx2fc_threads = {
+ .store = &bnx2fc_percpu.kthread,
+ .setup = bnx2fc_thread_setup,
+ .cleanup = bnx2fc_thread_cleanup,
+ .thread_should_run = bnx2fc_thread_should_run,
+ .thread_fn = bnx2fc_thread_io_process,
+ .park = bnx2fc_thread_park,
+ .unpark = bnx2fc_thread_unpark,
+ .thread_comm = "bnx2fc_thread/%u",
+};
+
/**
* bnx2fc_mod_init - module init entry point
*
@@ -2614,8 +2575,6 @@ static int __init bnx2fc_mod_init(void)
struct fcoe_percpu_s *bg;
struct task_struct *l2_thread;
int rc = 0;
- unsigned int cpu = 0;
- struct bnx2fc_percpu_s *p;
printk(KERN_INFO PFX "%s", version);
@@ -2657,23 +2616,7 @@ static int __init bnx2fc_mod_init(void)
bg->kthread = l2_thread;
spin_unlock_bh(&bg->fcoe_rx_list.lock);
- for_each_possible_cpu(cpu) {
- p = &per_cpu(bnx2fc_percpu, cpu);
- INIT_LIST_HEAD(&p->work_list);
- spin_lock_init(&p->fp_work_lock);
- }
-
- cpu_notifier_register_begin();
-
- for_each_online_cpu(cpu) {
- bnx2fc_percpu_thread_create(cpu);
- }
-
- /* Initialize per CPU interrupt thread */
- __register_hotcpu_notifier(&bnx2fc_cpu_notifier);
-
- cpu_notifier_register_done();
-
+ smpboot_register_percpu_thread(&bnx2fc_threads);
cnic_register_driver(CNIC_ULP_FCOE, &bnx2fc_cnic_cb);
return 0;
@@ -2695,7 +2638,6 @@ static void __exit bnx2fc_mod_exit(void)
struct fcoe_percpu_s *bg;
struct task_struct *l2_thread;
struct sk_buff *skb;
- unsigned int cpu = 0;
/*
* NOTE: Since cnic calls register_driver routine rtnl_lock,
@@ -2737,16 +2679,7 @@ static void __exit bnx2fc_mod_exit(void)
if (l2_thread)
kthread_stop(l2_thread);
- cpu_notifier_register_begin();
-
- /* Destroy per cpu threads */
- for_each_online_cpu(cpu) {
- bnx2fc_percpu_thread_destroy(cpu);
- }
-
- __unregister_hotcpu_notifier(&bnx2fc_cpu_notifier);
-
- cpu_notifier_register_done();
+ smpboot_unregister_percpu_thread(&bnx2fc_threads);
destroy_workqueue(bnx2fc_wq);
/*
diff --git a/drivers/scsi/bnx2fc/bnx2fc_hwi.c b/drivers/scsi/bnx2fc/bnx2fc_hwi.c
index 1427062e86f0..33aad48effaf 100644
--- a/drivers/scsi/bnx2fc/bnx2fc_hwi.c
+++ b/drivers/scsi/bnx2fc/bnx2fc_hwi.c
@@ -1049,14 +1049,14 @@ int bnx2fc_process_new_cqes(struct bnx2fc_rport *tgt)
fps = &per_cpu(bnx2fc_percpu, cpu);
spin_lock_bh(&fps->fp_work_lock);
- if (unlikely(!fps->iothread))
+ if (unlikely(!fps->active))
goto unlock;
work = bnx2fc_alloc_work(tgt, wqe);
if (work) {
list_add_tail(&work->list,
&fps->work_list);
- wake_up_process(fps->iothread);
+ wake_up_process(fps->kthread);
process = false;
}
unlock:
--
2.7.0
--
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