From nobody Sat Feb 7 20:38:41 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0FF17EB64DA for ; Tue, 18 Jul 2023 15:34:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233267AbjGRPed (ORCPT ); Tue, 18 Jul 2023 11:34:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34196 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232294AbjGRPeV (ORCPT ); Tue, 18 Jul 2023 11:34:21 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 69B0E172D for ; Tue, 18 Jul 2023 08:34:00 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 78AB56164C for ; Tue, 18 Jul 2023 15:33:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BC4A2C433C8; Tue, 18 Jul 2023 15:33:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1689694430; bh=mqwYcIZH+M6h8d7AW+YLg7/JE8kUv6dByMB/fsXMe5E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZauC2YoS57Y7Z75WX93K8wwq6vCm7vKYIrjQ7e1PVKNVB9oFy4zuFqlAHt/o9u8ig +jHL7t3YG0DIEB6aHqFTmfny58qvFcbf5CIXyGWvdZTy1e53lTQ536dn67rE17C/nX tNSMeABCJ0uBzJAhNRUYMbCjBerE73usUmO+jRF0pZkGkqrR+kns0jDAsySb5rrjm0 vJ0c0tNKTFlWD33YC5Vz/yDQMvPds538rFQgalIrZPB3wuBc466LP3kRSqQwFP4Ch0 oEvk6Z0ioJ5Hc+hwquvbxlp6Z83T51FMAMWjgZo4xqIpfbbJNOElQr6m7JucSJtx3Y kYKEx/dV4ZjKQ== From: Jisheng Zhang To: Paul Walmsley , Palmer Dabbelt , Albert Ou Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Conor Dooley Subject: [PATCH v3 2/2] riscv: enable DMA_BOUNCE_UNALIGNED_KMALLOC for !dma_coherent Date: Tue, 18 Jul 2023 23:22:14 +0800 Message-Id: <20230718152214.2907-3-jszhang@kernel.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230718152214.2907-1-jszhang@kernel.org> References: <20230718152214.2907-1-jszhang@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" With the DMA bouncing of unaligned kmalloc() buffers now in place, enable it for riscv when RISCV_DMA_NONCOHERENT=3Dy to allow the kmalloc-{8,16,32,96} caches. Since RV32 doesn't enable SWIOTLB yet, and I didn't see any dma noncoherent RV32 platforms in the mainline, so skip RV32 now by only enabling DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB is available. Once we see such requirement on RV32, we can enable it then. NOTE: we didn't force to create the swiotlb buffer even when the end of RAM is within the 32-bit physical address range. That's to say: For RV64 with > 4GB memory, the feature is enabled. For RV64 with <=3D 4GB memory, the feature isn't enabled by default. We rely on users to pass "swiotlb=3Dmmnn,force" where mmnn is the Number of I/O TLB slabs, see kernel-parameters.txt for details. Tested on Sipeed Lichee Pi 4A with 8GB DDR and Sipeed M1S BL808 Dock board. Signed-off-by: Jisheng Zhang Reviewed-by: Conor Dooley --- arch/riscv/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 4c07b9189c86..6681bd6ed2d7 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -267,6 +267,7 @@ config RISCV_DMA_NONCOHERENT select ARCH_HAS_SETUP_DMA_OPS select ARCH_HAS_SYNC_DMA_FOR_CPU select ARCH_HAS_SYNC_DMA_FOR_DEVICE + select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB select DMA_DIRECT_REMAP =20 config AS_HAS_INSN --=20 2.40.1