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From: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
To: linux-snps-arc@lists.infradead.org,
	Vineet Gupta <Vineet.Gupta1@synopsys.com>
Cc: linux-kernel@vger.kernel.org,
	Alexey Brodkin <Alexey.Brodkin@synopsys.com>,
	Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Subject: [PATCH 1/2] ARC: define __ALIGN_STR and __ALIGN symbols for ARC
Date: Wed, 11 Mar 2020 19:26:43 +0300	[thread overview]
Message-ID: <20200311162644.7667-1-Eugeniy.Paltsev@synopsys.com> (raw)

As of today ARC uses generic __ALIGN_STR and __ALIGN symbol
definitions from "include/linux/linkage.h"
They are defined to ".align 4,0x90" which instructed the assembler
to use `0x90` as a fill byte when aligning functions declared with
ENTRY or similar macroses. This leads to generated weird instructions
in code (when alignment is used) like "ldh_s r12,[r0,0x20]" which is
encoded as 0x9090 for ARCv2.

Let's use ".align 4" which insert a "nop_s" instruction instead.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
---
 arch/arc/include/asm/linkage.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arc/include/asm/linkage.h b/arch/arc/include/asm/linkage.h
index d9ee43c6b7db..fe19f1d412e7 100644
--- a/arch/arc/include/asm/linkage.h
+++ b/arch/arc/include/asm/linkage.h
@@ -29,6 +29,8 @@
 .endm
 
 #define ASM_NL		 `	/* use '`' to mark new line in macro */
+#define __ALIGN		.align 4
+#define __ALIGN_STR	__stringify(__ALIGN)
 
 /* annotation for data we want in DCCM - if enabled in .config */
 .macro ARCFP_DATA nm
-- 
2.21.1


             reply	other threads:[~2020-03-11 16:26 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-11 16:26 Eugeniy Paltsev [this message]
2020-03-11 16:26 ` [PATCH 2/2] ARC: don't align ret_from_exception function Eugeniy Paltsev
2020-03-11 17:38   ` Vineet Gupta
2020-03-11 20:58     ` Eugeniy Paltsev
2020-03-11 21:10       ` Vineet Gupta
2020-03-11 22:28         ` Eugeniy Paltsev
2020-03-11 16:35 ` [PATCH 1/2] ARC: define __ALIGN_STR and __ALIGN symbols for ARC Vineet Gupta

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