evl/poll: convert waiter list lock to hard lock

Very short sections of code outside of any hot path are protected by
such lock. Therefore we would not generally benefit from the
preemption disabling feature we are going to add to the EVL-specific
spinlock. Make it a hard lock to clarify the intent.
Signed-off-by: Philippe Gerum <rpm@xenomai.org>

kernel/evl/poll.c

@@ -12,7 +12,6 @@
 #include <linux/module.h>
 #include <linux/spinlock.h>
 #include <evl/file.h>
-#include <evl/lock.h>
 #include <evl/thread.h>
 #include <evl/memory.h>
 #include <evl/poll.h>
@@ -25,7 +24,7 @@ struct poll_group {
 	struct rb_root item_index;  /* struct poll_item */
 	struct list_head item_list; /* struct poll_item */
 	struct list_head waiter_list; /* struct poll_waiter */
-	evl_spinlock_t wait_lock;
+	hard_spinlock_t wait_lock;
 	struct evl_file efile;
 	struct evl_kmutex item_lock;
 	int nr_items;
@@ -575,13 +574,13 @@ int wait_events(struct file *filp,
 	timeout = timespec64_to_ktime(*ts64);
 	tmode = timeout ? EVL_ABS : EVL_REL;
 
-	evl_spin_lock_irqsave(&group->wait_lock, flags);
+	raw_spin_lock_irqsave(&group->wait_lock, flags);
 	list_add(&waiter.next, &group->waiter_list);
-	evl_spin_unlock_irqrestore(&group->wait_lock, flags);
+	raw_spin_unlock_irqrestore(&group->wait_lock, flags);
 	ret = evl_wait_flag_timeout(&waiter.flag, timeout, tmode);
-	evl_spin_lock_irqsave(&group->wait_lock, flags);
+	raw_spin_lock_irqsave(&group->wait_lock, flags);
 	list_del(&waiter.next);
-	evl_spin_unlock_irqrestore(&group->wait_lock, flags);
+	raw_spin_unlock_irqrestore(&group->wait_lock, flags);
 
 	count = ret;
 	if (count == 0)	/* Re-collect events after successful wait. */
@@ -613,7 +612,7 @@ static int poll_open(struct inode *inode, struct file *filp)
 	INIT_LIST_HEAD(&group->item_list);
 	INIT_LIST_HEAD(&group->waiter_list);
 	evl_init_kmutex(&group->item_lock);
-	evl_spin_lock_init(&group->wait_lock);
+	raw_spin_lock_init(&group->wait_lock);
 	filp->private_data = group;
 	stream_open(inode, filp);
 
@@ -634,10 +633,10 @@ static int poll_release(struct inode *inode, struct file *filp)
 	struct poll_waiter *waiter;
 	unsigned long flags;
 
-	evl_spin_lock_irqsave(&group->wait_lock, flags);
+	raw_spin_lock_irqsave(&group->wait_lock, flags);
 	list_for_each_entry(waiter, &group->waiter_list, next)
 		evl_flush_flag_nosched(&waiter->flag, T_RMID);
-	evl_spin_unlock_irqrestore(&group->wait_lock, flags);
+	raw_spin_unlock_irqrestore(&group->wait_lock, flags);
 	evl_schedule();
 
 	flush_items(group);