linux-kernel - [PATCH -next v4 5/7] arm64: mte: Clean up user tag accessors

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Date:   Wed, 20 Apr 2022 03:04:16 +0000
From:   Tong Tiangen <tongtiangen@...wei.com>
To:     Mark Rutland <mark.rutland@....com>,
        James Morse <james.morse@....com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        Robin Murphy <robin.murphy@....com>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will@...nel.org>,
        Alexander Viro <viro@...iv.linux.org.uk>,
        Michael Ellerman <mpe@...erman.id.au>,
        Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        Paul Mackerras <paulus@...ba.org>, <x86@...nel.org>,
        "H . Peter Anvin" <hpa@...or.com>
CC:     <linuxppc-dev@...ts.ozlabs.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>, <linux-mm@...ck.org>,
        Kefeng Wang <wangkefeng.wang@...wei.com>,
        Xie XiuQi <xiexiuqi@...wei.com>,
        Guohanjun <guohanjun@...wei.com>,
        Tong Tiangen <tongtiangen@...wei.com>
Subject: [PATCH -next v4 5/7] arm64: mte: Clean up user tag accessors

From: Robin Murphy <robin.murphy@....com>

Invoking user_ldst to explicitly add a post-increment of 0 is silly.
Just use a normal USER() annotation and save the redundant instruction.

Signed-off-by: Robin Murphy <robin.murphy@....com>
Reviewed-by: Tong Tiangen <tongtiangen@...wei.com>
---
 arch/arm64/lib/mte.S | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/lib/mte.S b/arch/arm64/lib/mte.S
index 8590af3c98c0..eeb9e45bcce8 100644
--- a/arch/arm64/lib/mte.S
+++ b/arch/arm64/lib/mte.S
@@ -93,7 +93,7 @@ SYM_FUNC_START(mte_copy_tags_from_user)
 	mov	x3, x1
 	cbz	x2, 2f
 1:
-	user_ldst 2f, ldtrb, w4, x1, 0
+USER(2f, ldtrb	w4, [x1])
 	lsl	x4, x4, #MTE_TAG_SHIFT
 	stg	x4, [x0], #MTE_GRANULE_SIZE
 	add	x1, x1, #1
@@ -120,7 +120,7 @@ SYM_FUNC_START(mte_copy_tags_to_user)
 1:
 	ldg	x4, [x1]
 	ubfx	x4, x4, #MTE_TAG_SHIFT, #MTE_TAG_SIZE
-	user_ldst 2f, sttrb, w4, x0, 0
+USER(2f, sttrb	w4, [x0])
 	add	x0, x0, #1
 	add	x1, x1, #MTE_GRANULE_SIZE
 	subs	x2, x2, #1
-- 
2.25.1