[PATCH 4.9 09/47] xen/evtchn: Change irq_info lock to raw_spinlock_t

[Greg Kroah-Hartman]

From: Luca Fancellu <luca.fancellu@xxxxxxx>

commit d120198bd5ff1d41808b6914e1eb89aff937415c upstream.

Unmask operation must be called with interrupt disabled,
on preempt_rt spin_lock_irqsave/spin_unlock_irqrestore
don't disable/enable interrupts, so use raw_* implementation
and change lock variable in struct irq_info from spinlock_t
to raw_spinlock_t

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 25da4618af24 ("xen/events: don't unmask an event channel when an eoi is pending")
Signed-off-by: Luca Fancellu <luca.fancellu@xxxxxxx>
Reviewed-by: Julien Grall <jgrall@xxxxxxxxxx>
Reviewed-by: Wei Liu <wei.liu@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210406105105.10141-1-luca.fancellu@xxxxxxx
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/xen/events/events_base.c     |   10 +++++-----
 drivers/xen/events/events_internal.h |    2 +-
 2 files changed, 6 insertions(+), 6 deletions(-)

--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -222,7 +222,7 @@ static int xen_irq_info_common_setup(str
 	info->evtchn = evtchn;
 	info->cpu = cpu;
 	info->mask_reason = EVT_MASK_REASON_EXPLICIT;
-	spin_lock_init(&info->lock);
+	raw_spin_lock_init(&info->lock);
 
 	ret = set_evtchn_to_irq(evtchn, irq);
 	if (ret < 0)
@@ -374,28 +374,28 @@ static void do_mask(struct irq_info *inf
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&info->lock, flags);
+	raw_spin_lock_irqsave(&info->lock, flags);
 
 	if (!info->mask_reason)
 		mask_evtchn(info->evtchn);
 
 	info->mask_reason |= reason;
 
-	spin_unlock_irqrestore(&info->lock, flags);
+	raw_spin_unlock_irqrestore(&info->lock, flags);
 }
 
 static void do_unmask(struct irq_info *info, u8 reason)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&info->lock, flags);
+	raw_spin_lock_irqsave(&info->lock, flags);
 
 	info->mask_reason &= ~reason;
 
 	if (!info->mask_reason)
 		unmask_evtchn(info->evtchn);
 
-	spin_unlock_irqrestore(&info->lock, flags);
+	raw_spin_unlock_irqrestore(&info->lock, flags);
 }
 
 #ifdef CONFIG_X86
--- a/drivers/xen/events/events_internal.h
+++ b/drivers/xen/events/events_internal.h
@@ -47,7 +47,7 @@ struct irq_info {
 	unsigned short eoi_cpu;	/* EOI must happen on this cpu */
 	unsigned int irq_epoch;	/* If eoi_cpu valid: irq_epoch of event */
 	u64 eoi_time;		/* Time in jiffies when to EOI. */
-	spinlock_t lock;
+	raw_spinlock_t lock;
 
 	union {
 		unsigned short virq;