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Message-Id: <20211130145156.946083-7-sashal@kernel.org>
Date: Tue, 30 Nov 2021 09:51:37 -0500
From: Sasha Levin <sashal@...nel.org>
To: linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc: Helge Deller <deller@....de>,
John David Anglin <dave.anglin@...l.net>,
Sasha Levin <sashal@...nel.org>,
James.Bottomley@...senPartnership.com, svens@...ckframe.org,
linux-parisc@...r.kernel.org
Subject: [PATCH AUTOSEL 5.4 07/25] parisc: Provide an extru_safe() macro to extract unsigned bits
From: Helge Deller <deller@....de>
[ Upstream commit 169d1a4a2adb2c246396c56aa2f9eec3868546f1 ]
The extru instruction leaves the most significant 32 bits of the
target register in an undefined state on PA 2.0 systems.
Provide a macro to safely use extru on 32- and 64-bit machines.
Suggested-by: John David Anglin <dave.anglin@...l.net>
Signed-off-by: Helge Deller <deller@....de>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
arch/parisc/include/asm/assembly.h | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/arch/parisc/include/asm/assembly.h b/arch/parisc/include/asm/assembly.h
index a39250cb7dfcf..0c95030017e8f 100644
--- a/arch/parisc/include/asm/assembly.h
+++ b/arch/parisc/include/asm/assembly.h
@@ -135,6 +135,17 @@
extrd,u \r, 63-(\sa), 64-(\sa), \t
.endm
+ /* Extract unsigned for 32- and 64-bit
+ * The extru instruction leaves the most significant 32 bits of the
+ * target register in an undefined state on PA 2.0 systems. */
+ .macro extru_safe r, p, len, t
+#ifdef CONFIG_64BIT
+ extrd,u \r, 32+(\p), \len, \t
+#else
+ extru \r, \p, \len, \t
+#endif
+ .endm
+
/* load 32-bit 'value' into 'reg' compensating for the ldil
* sign-extension when running in wide mode.
* WARNING!! neither 'value' nor 'reg' can be expressions
--
2.33.0
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