From nobody Sun Dec 14 12:14:42 2025 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 87DB0A47; Sun, 25 May 2025 02:23:43 +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=1748139827; cv=none; b=ZwiLBjKR/7S5a52UltUpA2vzfC0ikrzf/7+e1mTU6QdpK4YCl3BqIUFYITD9rp/5bPYA5aJZFebIa2qwTnmwaoDvI1eC3hUQQsC0nOuaLrbqbY0Hkfb7SrBkiamH1kkQOTyf0EYMfgcAUX76JNjt9wmue/vLkXWzACjYj5mw1qI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748139827; c=relaxed/simple; bh=tOa1RezbqxcE1EV5iKc3IbCwta9WIxyugED05gugQ/0=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=g1dedPcGGDvNYPPmymGRuFL9kcjhqXMPYlxsvEB3kPtd+aB2tR1GXFVJ6lbKbuJDb/2GEzjyL1mG/5J2/1LYKe8LQb4+lb+XZx5Lmot51lWUDcxXxpFJ14fIscJCz9R6mfagKTfMdM16kzfHInFgHy0TgyWNTg+5Q3D9Ys8dwN8= 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 _____8DxbKwufzJoFE_7AA--.12402S3; Sun, 25 May 2025 10:23:42 +0800 (CST) Received: from localhost.localdomain (unknown [223.64.69.3]) by front1 (Coremail) with SMTP id qMiowMDx+xonfzJolMjvAA--.26182S2; Sun, 25 May 2025 10:23:40 +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 V3] LoongArch: Avoid using $r0/$r1 as "mask" for csrxchg Date: Sun, 25 May 2025 10:23:25 +0800 Message-ID: <20250525022325.170964-1-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: qMiowMDx+xonfzJolMjvAA--.26182S2 X-CM-SenderInfo: hfkh0x5xdftxo6or00hjvr0hdfq/ X-Coremail-Antispam: 1Uk129KBj93XoWxXrW5Gw15ZFWxJr48Ww4UAwc_yoW5Xw47pr WDCr48KFs5WFyxA3yqqFnI93W3Wr97Gw4IyayDC397KFyqvr18ArZ5CF90qFWUJa1vva4I vFWYyw4SvF1DJabCm3ZEXasCq-sJn29KB7ZKAUJUUUUr529EdanIXcx71UUUUU7KY7ZEXa sCq-sGcSsGvfJ3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU 0xBIdaVrnRJUUU9Yb4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2 IYs7xG6rWj6s0DM7CIcVAFz4kK6r1Y6r17M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48v e4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Jr0_JF4l84ACjcxK6xIIjxv20xvEc7CjxVAFwI 0_Jr0_Gr1l84ACjcxK6I8E87Iv67AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVCY1x0267AK xVW8Jr0_Cr1UM2kKe7AKxVWUXVWUAwAS0I0E0xvYzxvE52x082IY62kv0487Mc804VCY07 AIYIkI8VC2zVCFFI0UMc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWU XVWUAwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7V AKI48JMxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMxCIbckI1I0E14v2 6r1Y6r17MI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17 CEb7AF67AKxVWUtVW8ZwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF 0xvE2Ix0cI8IcVCY1x0267AKxVWUJVW8JwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIx AIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVWUJVW8JbIYCTnIWIev Ja73UjIFyTuYvjxU2MKZDUUUU 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 < 21 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. V3: Update commit messages again. 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