linux-kernel - [PATCH v3 6/6] arm64: mm: Convert the opencoded field modify

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Message-ID: <20250417-field_modify-v3-6-6f7992aafcb7@quicinc.com>
Date: Thu, 17 Apr 2025 18:47:13 +0800
From: Luo Jie <quic_luoj@...cinc.com>
To: Yury Norov <yury.norov@...il.com>,
        Rasmus Villemoes
	<linux@...musvillemoes.dk>,
        Julia Lawall <Julia.Lawall@...ia.fr>,
        "Nicolas
 Palix" <nicolas.palix@...g.fr>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will@...nel.org>, Marc Zyngier <maz@...nel.org>,
        Oliver Upton
	<oliver.upton@...ux.dev>,
        Joey Gouly <joey.gouly@....com>,
        Suzuki K Poulose
	<suzuki.poulose@....com>,
        Zenghui Yu <yuzenghui@...wei.com>
CC: <linux-kernel@...r.kernel.org>, <cocci@...ia.fr>,
        <linux-arm-kernel@...ts.infradead.org>, <kvmarm@...ts.linux.dev>,
        <andrew@...n.ch>, <quic_kkumarcs@...cinc.com>,
        <quic_linchen@...cinc.com>, <quic_leiwei@...cinc.com>,
        <quic_suruchia@...cinc.com>, <quic_pavir@...cinc.com>,
        Luo Jie <quic_luoj@...cinc.com>
Subject: [PATCH v3 6/6] arm64: mm: Convert the opencoded field modify

Replaced below code with the wrapper FIELD_MODIFY(MASK, &reg, val)
- reg &= ~MASK;
- reg |= FIELD_PREP(MASK, val);
The semantic patch that makes this change is available
in scripts/coccinelle/misc/field_modify.cocci.

More information about semantic patching is available at
https://coccinelle.gitlabpages.inria.fr/website

Signed-off-by: Luo Jie <quic_luoj@...cinc.com>
---
 arch/arm64/mm/context.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/arm64/mm/context.c b/arch/arm64/mm/context.c
index b2ac06246327..4fbac8e74149 100644
--- a/arch/arm64/mm/context.c
+++ b/arch/arm64/mm/context.c
@@ -361,8 +361,7 @@ void cpu_do_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm)
 		ttbr0 |= FIELD_PREP(TTBR_ASID_MASK, asid);
 
 	/* Set ASID in TTBR1 since TCR.A1 is set */
-	ttbr1 &= ~TTBR_ASID_MASK;
-	ttbr1 |= FIELD_PREP(TTBR_ASID_MASK, asid);
+	FIELD_MODIFY(TTBR_ASID_MASK, &ttbr1, asid);
 
 	cpu_set_reserved_ttbr0_nosync();
 	write_sysreg(ttbr1, ttbr1_el1);

-- 
2.34.1