From nobody Sat Oct 4 17:31:19 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9258A3019CB; Thu, 14 Aug 2025 10:14:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755166497; cv=none; b=Hk2zp2vlvvaBrHDEMFVILZKZklZ6tZEhk9hw3u+9CKmRTgEg+r+rI/5r1qFkjleu4NlGiL7Y7hNWf6HXUFbM44YgBuaJj58KmbRgwhL7z9Bfo5P9tBWVBs5tipbW+UCoB/Mq1kQ/xA9u6cH4FCkU9fZNfFqUNRPpsZVZbnpuq+0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755166497; c=relaxed/simple; bh=VNpaHZYPDKoIVZk7JizQ+fAc7bXMl6IIrMQIwsKC7lg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=UR4BevQsG0dbK5JY/mGos9EQT9pY1vmjtbaF6Tdq3msqDCv/xLSjsyrKP4QRttVgfhCDflsLqz1yTTZHS3+Fqn0/nhqFlf7ehxhMreR4BZhlaj7XAImb8zmqev6gaITd1+4XuXokQ5biY6RYqSIxVBDrzw5E3ejP8gKsxtAOoy4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=sgcAjNmQ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="sgcAjNmQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6E732C4CEED; Thu, 14 Aug 2025 10:14:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755166497; bh=VNpaHZYPDKoIVZk7JizQ+fAc7bXMl6IIrMQIwsKC7lg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sgcAjNmQ4H9PR9eNw1PcsrGYJZDdCoIhSA00MB1PlPh4PY294zzHjmBNp/Feerkz5 onfh+H4AOnhzfctRKBnuKCZx/TKbia4qDj/ZGv49iPN8pTjetV2F9L2VUkgOWdWDRc XlrdyafRknSjL//iLlaNOBweJcYzh6FKt3CyXPCoJvTLjW4fEmAhBIfd9+UAEg8Pzu GT/aO6y+QSatuf+mIF+REo7cmsN0/u40Aqx/jFMMVRttbv3XnuIdoCIUPj7ks/cy6e xakUo8h2pDLy9UhEDhcLSzeOH+G0q/blCWi158fJN5vnT8J/3Fmo24+nsmO++3Zqz5 MlYCBR+W1ikrA== From: Leon Romanovsky To: Marek Szyprowski Cc: Leon Romanovsky , Jason Gunthorpe , Abdiel Janulgue , Alexander Potapenko , Alex Gaynor , Andrew Morton , Christoph Hellwig , Danilo Krummrich , iommu@lists.linux.dev, Jason Wang , Jens Axboe , Joerg Roedel , Jonathan Corbet , Juergen Gross , kasan-dev@googlegroups.com, Keith Busch , linux-block@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-nvme@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-trace-kernel@vger.kernel.org, Madhavan Srinivasan , Masami Hiramatsu , Michael Ellerman , "Michael S. Tsirkin" , Miguel Ojeda , Robin Murphy , rust-for-linux@vger.kernel.org, Sagi Grimberg , Stefano Stabellini , Steven Rostedt , virtualization@lists.linux.dev, Will Deacon , xen-devel@lists.xenproject.org Subject: [PATCH v2 15/16] block-dma: properly take MMIO path Date: Thu, 14 Aug 2025 13:13:33 +0300 Message-ID: <87b7d3a0e3f6be9da49947923d52355ed0835833.1755153054.git.leon@kernel.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: References: 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 Content-Type: text/plain; charset="utf-8" From: Leon Romanovsky Make sure that CPU is not synced and IOMMU is configured to take MMIO path by providing newly introduced DMA_ATTR_MMIO attribute. Signed-off-by: Leon Romanovsky --- block/blk-mq-dma.c | 13 +++++++++++-- include/linux/blk-mq-dma.h | 6 +++++- include/linux/blk_types.h | 2 ++ 3 files changed, 18 insertions(+), 3 deletions(-) diff --git a/block/blk-mq-dma.c b/block/blk-mq-dma.c index 37e2142be4f7..d415088ed9fd 100644 --- a/block/blk-mq-dma.c +++ b/block/blk-mq-dma.c @@ -87,8 +87,13 @@ static bool blk_dma_map_bus(struct blk_dma_iter *iter, s= truct phys_vec *vec) static bool blk_dma_map_direct(struct request *req, struct device *dma_dev, struct blk_dma_iter *iter, struct phys_vec *vec) { + unsigned int attrs =3D 0; + + if (req->cmd_flags & REQ_MMIO) + attrs =3D DMA_ATTR_MMIO; + iter->addr =3D dma_map_phys(dma_dev, vec->paddr, vec->len, - rq_dma_dir(req), 0); + rq_dma_dir(req), attrs); if (dma_mapping_error(dma_dev, iter->addr)) { iter->status =3D BLK_STS_RESOURCE; return false; @@ -103,14 +108,17 @@ static bool blk_rq_dma_map_iova(struct request *req, = struct device *dma_dev, { enum dma_data_direction dir =3D rq_dma_dir(req); unsigned int mapped =3D 0; + unsigned int attrs =3D 0; int error; =20 iter->addr =3D state->addr; iter->len =3D dma_iova_size(state); + if (req->cmd_flags & REQ_MMIO) + attrs =3D DMA_ATTR_MMIO; =20 do { error =3D dma_iova_link(dma_dev, state, vec->paddr, mapped, - vec->len, dir, 0); + vec->len, dir, attrs); if (error) break; mapped +=3D vec->len; @@ -176,6 +184,7 @@ bool blk_rq_dma_map_iter_start(struct request *req, str= uct device *dma_dev, * same as non-P2P transfers below and during unmap. */ req->cmd_flags &=3D ~REQ_P2PDMA; + req->cmd_flags |=3D REQ_MMIO; break; default: iter->status =3D BLK_STS_INVAL; diff --git a/include/linux/blk-mq-dma.h b/include/linux/blk-mq-dma.h index c26a01aeae00..6c55f5e58511 100644 --- a/include/linux/blk-mq-dma.h +++ b/include/linux/blk-mq-dma.h @@ -48,12 +48,16 @@ static inline bool blk_rq_dma_map_coalesce(struct dma_i= ova_state *state) static inline bool blk_rq_dma_unmap(struct request *req, struct device *dm= a_dev, struct dma_iova_state *state, size_t mapped_len) { + unsigned int attrs =3D 0; + if (req->cmd_flags & REQ_P2PDMA) return true; =20 if (dma_use_iova(state)) { + if (req->cmd_flags & REQ_MMIO) + attrs =3D DMA_ATTR_MMIO; dma_iova_destroy(dma_dev, state, mapped_len, rq_dma_dir(req), - 0); + attrs); return true; } =20 diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 09b99d52fd36..283058bcb5b1 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -387,6 +387,7 @@ enum req_flag_bits { __REQ_FS_PRIVATE, /* for file system (submitter) use */ __REQ_ATOMIC, /* for atomic write operations */ __REQ_P2PDMA, /* contains P2P DMA pages */ + __REQ_MMIO, /* contains MMIO memory */ /* * Command specific flags, keep last: */ @@ -420,6 +421,7 @@ enum req_flag_bits { #define REQ_FS_PRIVATE (__force blk_opf_t)(1ULL << __REQ_FS_PRIVATE) #define REQ_ATOMIC (__force blk_opf_t)(1ULL << __REQ_ATOMIC) #define REQ_P2PDMA (__force blk_opf_t)(1ULL << __REQ_P2PDMA) +#define REQ_MMIO (__force blk_opf_t)(1ULL << __REQ_MMIO) =20 #define REQ_NOUNMAP (__force blk_opf_t)(1ULL << __REQ_NOUNMAP) =20 --=20 2.50.1