Patch "powerpc/opal-irqchip: Fix double endian conversion" has been added to the 4.3-stable tree

PATCH [email protected] 1 participant 1 message Jan 27, 2016

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2016-01-27 07:00 UTC #0 lore raw

This is a note to let you know that I've just added the patch titled

powerpc/opal-irqchip: Fix double endian conversion

to the 4.3-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
powerpc-opal-irqchip-fix-double-endian-conversion.patch
and it can be found in the queue-4.3 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From 25642e1459ace29f6ce5a171efc8b7b59a52a2d4 Mon Sep 17 00:00:00 2001

From: Alistair Popple <[email protected]>
Date: Mon, 7 Dec 2015 11:28:28 +1100
Subject: powerpc/opal-irqchip: Fix double endian conversion

From: Alistair Popple <[email protected]>

commit 25642e1459ace29f6ce5a171efc8b7b59a52a2d4 upstream.

The OPAL event calls return a mask of events that are active in big endian format. This is checked when unmasking the events in the irqchip by comparison with a cached value. The cached value was stored in big endian format but should've been converted to CPU endian first.

This bug leads to OPAL event delivery being delayed or dropped on some systems. Symptoms may include a non-functional console.

The bug is fixed by calling opal_handle_events(...) instead of duplicating code in opal_event_unmask(...).

Fixes 9f0fd0499d30 ("powerpc/powernv: Add a virtual irqchip for opal events")

Reported-by Douglas L Lehr <[email protected]>

Signed-off-by Alistair Popple <[email protected]>

Signed-off-by Michael Ellerman <[email protected]>

Signed-off-by Greg Kroah-Hartman <[email protected]>

---
 arch/powerpc/platforms/powernv/opal-irqchip.c |   58 +++++++++++++-------------
 1 file changed, 29 insertions(+), 29 deletions(-)

arch/powerpc/platforms/powernv/opal-irqchip.c +29 ~~-29~~

@@ -43,11 +43,34 @@ static unsigned int opal_irq_count;
 static unsigned int *opal_irqs;
 
 static void opal_handle_irq_work(struct irq_work *work);
-static __be64 last_outstanding_events;
+static u64 last_outstanding_events;
 static struct irq_work opal_event_irq_work = {
 	.func = opal_handle_irq_work,
 };
 
+void opal_handle_events(uint64_t events)
+{
+	int virq, hwirq = 0;
+	u64 mask = opal_event_irqchip.mask;
+
+	if (!in_irq() && (events & mask)) {
+		last_outstanding_events = events;
+		irq_work_queue(&opal_event_irq_work);
+		return;
+	}
+
+	while (events & mask) {
+		hwirq = fls64(events) - 1;
+		if (BIT_ULL(hwirq) & mask) {
+			virq = irq_find_mapping(opal_event_irqchip.domain,
+						hwirq);
+			if (virq)
+				generic_handle_irq(virq);
+		}
+		events &= ~BIT_ULL(hwirq);
+	}
+}
+
 static void opal_event_mask(struct irq_data *d)
 {
 	clear_bit(d->hwirq, &opal_event_irqchip.mask);

@@ -55,12 +78,12 @@ static void opal_event_mask(struct irq_d
 
 static void opal_event_unmask(struct irq_data *d)
 {
+	__be64 events;
+
 	set_bit(d->hwirq, &opal_event_irqchip.mask);
 
-	opal_poll_events(&last_outstanding_events);
-	if (last_outstanding_events & opal_event_irqchip.mask)
-		/* Need to retrigger the interrupt */
-		irq_work_queue(&opal_event_irq_work);
+	opal_poll_events(&events);
+	opal_handle_events(be64_to_cpu(events));
 }
 
 static int opal_event_set_type(struct irq_data *d, unsigned int flow_type)

@@ -96,29 +119,6 @@ static int opal_event_map(struct irq_dom
 	return 0;
 }
 
-void opal_handle_events(uint64_t events)
-{
-	int virq, hwirq = 0;
-	u64 mask = opal_event_irqchip.mask;
-
-	if (!in_irq() && (events & mask)) {
-		last_outstanding_events = events;
-		irq_work_queue(&opal_event_irq_work);
-		return;
-	}
-
-	while (events & mask) {
-		hwirq = fls64(events) - 1;
-		if (BIT_ULL(hwirq) & mask) {
-			virq = irq_find_mapping(opal_event_irqchip.domain,
-						hwirq);
-			if (virq)
-				generic_handle_irq(virq);
-		}
-		events &= ~BIT_ULL(hwirq);
-	}
-}
-
 static irqreturn_t opal_interrupt(int irq, void *data)
 {
 	__be64 events;

@@ -131,7 +131,7 @@ static irqreturn_t opal_interrupt(int ir
 
 static void opal_handle_irq_work(struct irq_work *work)
 {
-	opal_handle_events(be64_to_cpu(last_outstanding_events));
+	opal_handle_events(last_outstanding_events);
 }
 
 static int opal_event_match(struct irq_domain *h, struct device_node *node,

Patches currently in stable-queue which might be from [email protected] are

queue-4.3/powerpc-opal-irqchip-fix-double-endian-conversion.patch queue-4.3/powerpc-opal-irqchip-fix-deadlock-introduced-by-fix-double-endian-conversion.patch