Patch "[PATCH 069/135] irqchip/gic-v3: Make sure read from ICC_IAR1_EL1 is" has been added to the 4.4-stable tree

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

    [PATCH 069/135] irqchip/gic-v3: Make sure read from ICC_IAR1_EL1 is

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:

     0069-irqchip-gic-v3-Make-sure-read-from-ICC_IAR1_EL1-is-v.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 <[email protected]> know about it.

From: Tirumalesh Chalamarla <[email protected]>
Date: Thu, 4 Feb 2016 10:45:25 -0800
Subject: [PATCH 069/135] irqchip/gic-v3: Make sure read from ICC_IAR1_EL1 is
visible on redestributor

[ Upstream commit 1a1ebd5fb1e203ee8cc73508cc7a38ac4b804596 ]

The ARM GICv3 specification mentions the need for dsb after a read from the ICC_IAR1_EL1 register:

4.1.1 Physical CPU Interface:
The effects of reading ICC_IAR0_EL1 and ICC_IAR1_EL1 on the state of a returned INTID are not guaranteed to be visible until after the execution of a DSB.

Not having this could result in missed interrupts, so let's add the required barrier.

[Marc: fixed commit message]

---
 arch/arm64/include/asm/arch_gicv3.h |    1 +
 1 file changed, 1 insertion(+)

@@ -103,6 +103,7 @@ static inline u64 gic_read_iar_common(vo
 	u64 irqstat;
 
 	asm volatile("mrs_s %0, " __stringify(ICC_IAR1_EL1) : "=r" (irqstat));
+	dsb(sy);
 	return irqstat;
 }
 

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

queue-4.4/0070-arm64-KVM-Configure-TCR_EL2.PS-at-runtime.patch queue-4.4/0069-irqchip-gic-v3-Make-sure-read-from-ICC_IAR1_EL1-is-v.patch queue-4.4/0084-ahci-Workaround-for-ThunderX-Errata-22536.patch