From nobody Fri Dec 19 10:44:43 2025 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 06E4415E5AE; Wed, 26 Mar 2025 10:21:09 +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=1742984474; cv=none; b=LtDHa7mmjYan4RHM2VDjNxDuSBpF7mc89ttgLoaI0YN3U7Obm+PP+11Oam3cvUec3ABkVPwy8GoDkgU6wUwrlGhB9EQ12vkpPT0i9MoKIV9aPSBWQvpzhLtrx+hWadx8CjSbUMoVT45MzRSnHtCUNZJ774vYHyfWjBWRiz1b1U4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742984474; c=relaxed/simple; bh=IvOKAsn08B3ShbzuaKcFNHFzZEOgIQqjw5V6wsRAbHc=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=tnKSsOc+uXsVO5aE1oD3aHwocTfeyVpyNen6fYzHRRjywPuc8BIYiLhVvKu/0yKyiaYVFQkYue6j7uyF+N3y6V8QLXBOx1/c/1O0qj+QeXXHboK+DTgbtdUYNuHPXDuIpmFTm+1HpkgD6Gro7VX/xpEMmiv/bjdmg3KLrGkUkmU= 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 [223.64.68.198]) by gateway (Coremail) with SMTP id _____8CxvOIO1eNnkvKmAA--.19153S3; Wed, 26 Mar 2025 18:21:02 +0800 (CST) Received: from localhost.localdomain (unknown [223.64.68.198]) by front1 (Coremail) with SMTP id qMiowMBxWsQK1eNnUVJhAA--.26182S2; Wed, 26 Mar 2025 18:21:01 +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, loongson-kernel@lists.loongnix.cn, Huacai Chen , stable@vger.kernel.org, Binbin Zhou Subject: [PATCH] LoongArch: Increase ARCH_DMA_MINALIGN to 16 Date: Wed, 26 Mar 2025 18:20:51 +0800 Message-ID: <20250326102051.2313133-1-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: qMiowMBxWsQK1eNnUVJhAA--.26182S2 X-CM-SenderInfo: hfkh0x5xdftxo6or00hjvr0hdfq/ X-Coremail-Antispam: 1Uk129KBj9xXoWrKFyrXF4DGryrKw47KrW7trc_yoWkCFg_Wa 47Ww4DGr18Jw47twsFq393Wr4jg3yxXF9Y9r9aqr1aya43twn8X3yrC343Ar4YkrWDCFs5 ZayrtF9YkryY9osvyTuYvTs0mTUanT9S1TB71UUUUUJqnTZGkaVYY2UrUUUUj1kv1TuYvT s0mT0YCTnIWjqI5I8CrVACY4xI64kE6c02F40Ex7xfYxn0WfASr-VFAUDa7-sFnT9fnUUI cSsGvfJTRUUUbVkYFVCjjxCrM7AC8VAFwI0_Jr0_Gr1l1xkIjI8I6I8E6xAIw20EY4v20x vaj40_Wr0E3s1l1IIY67AEw4v_Jrv_JF1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxS w2x7M28EF7xvwVC0I7IYx2IY67AKxVW8JVW5JwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxV W8JVWxJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0 oVCq3wAaw2AFwI0_Jrv_JF1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqjxCEc2xF0cIa02 0Ex4CE44I27wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_Jrv_JF1l Yx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrw CF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwCFI7km07C267AKxVWUXVWU AwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1V AFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xII jxv20xvEc7CjxVAFwI0_Jr0_Gr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4 A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Jr0_GrUvcSsGvfC2KfnxnUUI 43ZEXa7IU8hiSPUUUUU== Content-Type: text/plain; charset="utf-8" ARCH_DMA_MINALIGN is 1 by default, but some LoongArch-specific devices (such as APBDMA) require 16 bytes alignment. When the data buffer length is too small, the hardware may make an error writing cacheline. Thus, it is dangerous to allocate a small memory buffer for DMA. It's always safe to define ARCH_DMA_MINALIGN as L1_CACHE_BYTES but unnecessary (kmalloc() need small memory objects). Therefore, just increase it to 16. Cc: stable@vger.kernel.org Tested-by: Binbin Zhou Signed-off-by: Huacai Chen --- arch/loongarch/include/asm/cache.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/loongarch/include/asm/cache.h b/arch/loongarch/include/as= m/cache.h index 1b6d09617199..aa622c754414 100644 --- a/arch/loongarch/include/asm/cache.h +++ b/arch/loongarch/include/asm/cache.h @@ -8,6 +8,8 @@ #define L1_CACHE_SHIFT CONFIG_L1_CACHE_SHIFT #define L1_CACHE_BYTES (1 << L1_CACHE_SHIFT) =20 +#define ARCH_DMA_MINALIGN (16) + #define __read_mostly __section(".data..read_mostly") =20 #endif /* _ASM_CACHE_H */ --=20 2.47.1