Patch "genirq: Provide irq_gc_{lock_irqsave,unlock_irqrestore}() helpers" has been added to the 4.4-stable tree

Patch "genirq: Provide irq_gc_{lock_irqsave,unlock_irqrestore}() helpers" has been added to the 4.4-stable tree

[gregkh]

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

    genirq: Provide irq_gc_{lock_irqsave,unlock_irqrestore}() helpers

to the 4.4-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:
     genirq-provide-irq_gc_-lock_irqsave-unlock_irqrestore-helpers.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From ebf9ff753c041b296241990aef76163bbb2cc9c8 Mon Sep 17 00:00:00 2001
From: Boris Brezillon <boris.brezillon@free-electrons.com>
Date: Tue, 13 Sep 2016 15:58:28 +0200
Subject: genirq: Provide irq_gc_{lock_irqsave,unlock_irqrestore}() helpers

From: Boris Brezillon <boris.brezillon@free-electrons.com>

commit ebf9ff753c041b296241990aef76163bbb2cc9c8 upstream.

Some irqchip drivers need to take the generic chip lock outside of the
irq context.

Provide the irq_gc_{lock_irqsave,unlock_irqrestore}() helpers to allow
one to disable irqs while entering a critical section protected by
gc->lock.

Note that we do not provide optimized version of these helpers for !SMP,
because they are not called from the hot-path.

[ tglx: Added a comment when these helpers should be [not] used ]

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Link: http://lkml.kernel.org/r/1473775109-4192-1-git-send-email-boris.brezillon@free-electrons.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 include/linux/irq.h |   10 ++++++++++
 1 file changed, 10 insertions(+)

--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -916,6 +916,16 @@ static inline void irq_gc_lock(struct ir
 static inline void irq_gc_unlock(struct irq_chip_generic *gc) { }
 #endif
 
+/*
+ * The irqsave variants are for usage in non interrupt code. Do not use
+ * them in irq_chip callbacks. Use irq_gc_lock() instead.
+ */
+#define irq_gc_lock_irqsave(gc, flags)	\
+	raw_spin_lock_irqsave(&(gc)->lock, flags)
+
+#define irq_gc_unlock_irqrestore(gc, flags)	\
+	raw_spin_unlock_irqrestore(&(gc)->lock, flags)
+
 static inline void irq_reg_writel(struct irq_chip_generic *gc,
 				  u32 val, int reg_offset)
 {


Patches currently in stable-queue which might be from boris.brezillon@free-electrons.com are

queue-4.4/irqchip-atmel-aic-fix-potential-deadlock-in-xlate.patch
queue-4.4/drm-atmel-hlcdc-fix-vertical-scaling.patch
queue-4.4/genirq-provide-irq_gc_-lock_irqsave-unlock_irqrestore-helpers.patch