Thread (2 messages) flat view 2 messages, 2 authors, 2017-03-07

[PATCH] irqchip/gic-v3: Fix GICD_CTLR_ARE_NS bit field

From: Marc Zyngier <hidden>
Date: 2017-03-07 07:42:41
Also in: lkml, stable

On Tue, Mar 07 2017 at  4:07:05 am GMT, Alim Akhtar [off-list ref] wrote:
quoted hunk
From: Alim Akhtar <redacted>

As per GICv3 Architecture specification 8.9.4 field descriptions,
GICD_CTLR_ARE_NS is bit[5]. This patch correct the same.

Fixes: 021f6537 ("irqchip: gic-v3: Initial support for GICv3")
Cc: stable at vger.kernel.org
Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
---
 include/linux/irqchip/arm-gic-v3.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
index e808f8a..4aaf639 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -57,7 +57,7 @@
 
 #define GICD_CTLR_RWP			(1U << 31)
 #define GICD_CTLR_DS			(1U << 6)
-#define GICD_CTLR_ARE_NS		(1U << 4)
+#define GICD_CTLR_ARE_NS		(1U << 5)
 #define GICD_CTLR_ENABLE_G1A		(1U << 1)
 #define GICD_CTLR_ENABLE_G1		(1U << 0)
No, the issue is much more subtle.

- When the access is secure in a system that supports two security
  states, this is bit[5] indeed.

- When the access is non-secure in a system that supports two security
  states, this is bit[4] (so that software written for a single security
  mode can run on both side of the security fence).

- In a system that only supports a single security state, this is bit[4]
  too.

Given that Linux is only designed to run on the non-secure side (at
least when paired with GICv3), I stand by my original bit layout.

Thanks,

        M.
-- 
Jazz is not dead, it just smell funny.
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