xen/evtchn: Change irq_info lock to raw_spinlock_t

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@vger.kernel.org
Fixes: 25da4618af24 ("xen/events: don't unmask an event channel when an eoi is pending")
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/20210406105105.10141-1-luca.fancellu@arm.com
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index 8236e23..7bbfd58 100644 (file)
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -110,7 +110,7 @@ struct irq_info {
        unsigned short eoi_cpu; /* EOI must happen on this cpu-1 */
        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;
@@ -312,7 +312,7 @@ static int xen_irq_info_common_setup(struct irq_info *info,
        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)
@@ -472,28 +472,28 @@ static void do_mask(struct irq_info *info, u8 reason)
 {
        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