[PATCH 5.11 014/210] xen/evtchn: Change irq_info lock to raw_spinlock_t

Greg Kroah-Hartman
2021-04-12T09:23:13Z

From: Luca Fancellu <luca.fancellu@arm.com>

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@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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/xen/events/events_base.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -109,7 +109,7 @@ 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;
@@ -310,7 +310,7 @@ 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)
@@ -463,28 +463,28 @@ 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