[tip:irq/urgent] irqchip/gic-v3-its: Add missing cache flushes

[tip-bot for Marc Zyngier]

Commit-ID:  5a9a8915c8888b615521b17d70a4342187eae60b
Gitweb:     http://git.kernel.org/tip/5a9a8915c8888b615521b17d70a4342187eae60b
Author:     Marc Zyngier <marc.zyngier@xxxxxxx>
AuthorDate: Sun, 13 Sep 2015 12:14:32 +0100
Committer:  Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Tue, 15 Sep 2015 17:06:29 +0200

irqchip/gic-v3-its: Add missing cache flushes

When the ITS is configured for non-cacheable transactions, make sure
that the allocated, zeroed memory is flushed to the Point of
Coherency, allowing the ITS to observe the zeros instead of random
garbage (or even get its own data overwritten by zeros being evicted
from the cache...).

Fixes: 241a386c7dbb "irqchip: gicv3-its: Use non-cacheable accesses when no shareability"
Reported-and-tested-by: Stuart Yoder <stuart.yoder@xxxxxxxxxxxxx>
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: Pavel Fedin <p.fedin@xxxxxxxxxxx>
Cc: Jason Cooper <jason@xxxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1442142873-20213-3-git-send-email-marc.zyngier@xxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
 drivers/irqchip/irq-gic-v3-its.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 26b55c5..ac7ae2b 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -898,8 +898,10 @@ retry_baser:
 			 * non-cacheable as well.
 			 */
 			shr = tmp & GITS_BASER_SHAREABILITY_MASK;
-			if (!shr)
+			if (!shr) {
 				cache = GITS_BASER_nC;
+				__flush_dcache_area(base, alloc_size);
+			}
 			goto retry_baser;
 		}
 
@@ -1140,6 +1142,8 @@ static struct its_device *its_create_device(struct its_node *its, u32 dev_id,
 		return NULL;
 	}
 
+	__flush_dcache_area(itt, sz);
+
 	dev->its = its;
 	dev->itt = itt;
 	dev->nr_ites = nr_ites;
--
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