From nobody Fri Dec 19 16:04:42 2025 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by smtp.subspace.kernel.org (Postfix) with ESMTP id AE3C94C98; Sat, 24 May 2025 14:24:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=114.242.206.163 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748096657; cv=none; b=SGZTey4r6z9FYldUVFZyffnakwKrl7PkOdCv+bbRvchZksgfZXPtMyxP8cqwrPFn/f+5LzLBsOrAprDy/tp2yVSVt+EWQpv87YfD0jYRM5SsRtpyFHVvnAWu7UUqAq9j4dp3YSoITiZskQyb4Qb+eYZnyo2AI39piHFIdPhQ84w= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748096657; c=relaxed/simple; bh=YIn4cxuq8l5X/t94M2XArJDtJ96LRqho2wSWWb6qtf4=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=F34Cwba4TlzFbeW90HLPXtrXN+XSOMl3tOhI/RqBj4H/qXHu/56PbjkviA/bz4m+/K87Y+hPxXwmnZfMOJM6bdrCxKcMnRkZf5GAyIMDkBxH03QMPzr37D8gQqsPsW+dTZmtGTB4dOiLRTtW6eduZb8m71xBDI7FFIur0Vn/Hx8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn; spf=pass smtp.mailfrom=loongson.cn; arc=none smtp.client-ip=114.242.206.163 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=loongson.cn Received: from loongson.cn (unknown [223.64.69.3]) by gateway (Coremail) with SMTP id _____8Bx12mD1jFo14r6AA--.11055S3; Sat, 24 May 2025 22:24:03 +0800 (CST) Received: from localhost.localdomain (unknown [223.64.69.3]) by front1 (Coremail) with SMTP id qMiowMAxX8d61jFoE33uAA--.60746S2; Sat, 24 May 2025 22:24:02 +0800 (CST) From: Huacai Chen To: Huacai Chen Cc: loongarch@lists.linux.dev, Xuefeng Li , Guo Ren , Xuerui Wang , Jiaxun Yang , linux-kernel@vger.kernel.org, Huacai Chen , stable@vger.kernel.org, Yanteng Si , WANG Rui Subject: [PATCH V2] LoongArch: Avoid using $r0/$r1 as "mask" for csrxchg Date: Sat, 24 May 2025 22:23:45 +0800 Message-ID: <20250524142345.8045-1-chenhuacai@loongson.cn> X-Mailer: git-send-email 2.47.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: qMiowMAxX8d61jFoE33uAA--.60746S2 X-CM-SenderInfo: hfkh0x5xdftxo6or00hjvr0hdfq/ X-Coremail-Antispam: 1Uk129KBj93XoWxXrW5Gw15ZFWxJr48Ww4UAwc_yoW5XFyxpF WkCr48KFs5WFyxA3yqqFnI93W7Wr97Gw4IyayDC397KF1DZr18ArZ5CF90qFWUGa1vva4I vFWYyw4S9F1DJabCm3ZEXasCq-sJn29KB7ZKAUJUUUUr529EdanIXcx71UUUUU7KY7ZEXa sCq-sGcSsGvfJ3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU 0xBIdaVrnRJUUU9jb4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2 IYs7xG6rWj6s0DM7CIcVAFz4kK6r1Y6r17M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48v e4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_JFI_Gr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI 0_Jr0_Gr1l84ACjcxK6I8E87Iv67AKxVWxJr0_GcWl84ACjcxK6I8E87Iv6xkF7I0E14v2 6F4UJVW0owAaw2AFwI0_Jrv_JF1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqjxCEc2xF0c Ia020Ex4CE44I27wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_Jrv_ JF1lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwI xGrwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwCFI7km07C267AKxVWU XVWUAwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67 kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY 6xIIjxv20xvEc7CjxVAFwI0_Jr0_Gr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0x vEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Jr0_GrUvcSsGvfC2Kfnx nUUI43ZEXa7IU8hiSPUUUUU== Content-Type: text/plain; charset="utf-8" When building kernel with LLVM there are occasionally such errors: In file included from ./include/linux/spinlock.h:59: In file included from ./include/linux/irqflags.h:17: arch/loongarch/include/asm/irqflags.h:38:3: error: must not be $r0 or $r1 38 | "csrxchg %[val], %[mask], %[reg]\n\t" | ^ :1:16: note: instantiated into assembly here 1 | csrxchg $a1, $ra, 0 | ^ To prevent the compiler from allocating $r0 or $r1 for the "mask" of the csrxchg instruction, the 'q' constraint must be used but Clang < 22 does not support it. So force to use $t0 in the inline asm, in order to avoid using $r0/$r1 while keeping the backward compatibility. Cc: stable@vger.kernel.org Link: https://github.com/llvm/llvm-project/pull/141037 Reviewed-by: Yanteng Si Suggested-by: WANG Rui Signed-off-by: Huacai Chen --- V2: Update commit messages. arch/loongarch/include/asm/irqflags.h | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/arch/loongarch/include/asm/irqflags.h b/arch/loongarch/include= /asm/irqflags.h index 319a8c616f1f..003172b8406b 100644 --- a/arch/loongarch/include/asm/irqflags.h +++ b/arch/loongarch/include/asm/irqflags.h @@ -14,40 +14,48 @@ static inline void arch_local_irq_enable(void) { u32 flags =3D CSR_CRMD_IE; + register u32 mask asm("t0") =3D CSR_CRMD_IE; + __asm__ __volatile__( "csrxchg %[val], %[mask], %[reg]\n\t" : [val] "+r" (flags) - : [mask] "r" (CSR_CRMD_IE), [reg] "i" (LOONGARCH_CSR_CRMD) + : [mask] "r" (mask), [reg] "i" (LOONGARCH_CSR_CRMD) : "memory"); } =20 static inline void arch_local_irq_disable(void) { u32 flags =3D 0; + register u32 mask asm("t0") =3D CSR_CRMD_IE; + __asm__ __volatile__( "csrxchg %[val], %[mask], %[reg]\n\t" : [val] "+r" (flags) - : [mask] "r" (CSR_CRMD_IE), [reg] "i" (LOONGARCH_CSR_CRMD) + : [mask] "r" (mask), [reg] "i" (LOONGARCH_CSR_CRMD) : "memory"); } =20 static inline unsigned long arch_local_irq_save(void) { u32 flags =3D 0; + register u32 mask asm("t0") =3D CSR_CRMD_IE; + __asm__ __volatile__( "csrxchg %[val], %[mask], %[reg]\n\t" : [val] "+r" (flags) - : [mask] "r" (CSR_CRMD_IE), [reg] "i" (LOONGARCH_CSR_CRMD) + : [mask] "r" (mask), [reg] "i" (LOONGARCH_CSR_CRMD) : "memory"); return flags; } =20 static inline void arch_local_irq_restore(unsigned long flags) { + register u32 mask asm("t0") =3D CSR_CRMD_IE; + __asm__ __volatile__( "csrxchg %[val], %[mask], %[reg]\n\t" : [val] "+r" (flags) - : [mask] "r" (CSR_CRMD_IE), [reg] "i" (LOONGARCH_CSR_CRMD) + : [mask] "r" (mask), [reg] "i" (LOONGARCH_CSR_CRMD) : "memory"); } =20 --=20 2.47.1