From nobody Sun Nov 24 09:20:26 2024 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 ED1FC1E495; Sun, 10 Nov 2024 13:48:12 +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=1731246493; cv=none; b=WE+BiiD36xIhulri/o5Pw8Yt0oUWXS/FDWNAB3e9dgMHdCjM+Zg+PZQbuD0940F5fC6HB37HY0wzkTtmmGfJOKoAErLDJWaWs98Z/BzA6TnJTFXO6Uc3gqcC1lxE47qlsrw8D5DtkOiy6gHXNs4aZ8+HmVChbHrm3kcfDoSieqc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731246493; c=relaxed/simple; bh=pdG8tJYtOOpW9U88JXztIsRHViZt5iy73W9I0cDiHOE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=D12+SjzkGIC3XGerEtVwHBIEWdtkZCqNbdduZawTlZDdlkXM2PRztX/gpL79T8+uAuVr0Hej1e0/6fmZD3RgVszox/EdetaLBASGLDOsWgLjK8Vy8i4y1EX87zxZd1MlFxsqUIzMC/PHboSbzt2xdGWbTt2AsC9KcidGrSLRqkk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=pbpZa65v; 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="pbpZa65v" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5A46FC4CECD; Sun, 10 Nov 2024 13:48:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1731246492; bh=pdG8tJYtOOpW9U88JXztIsRHViZt5iy73W9I0cDiHOE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pbpZa65vIR2DqPSZ4TsPvtcw/+wMVaVuzHxc3556j06QBCSQPo8LTQLVlo3p5cEgx JtWAtYHyo2H3tyg1+4RE7PP6xXCdeWJ5pL4/yLDO7TyLDwiPNFaKJDJKeIS5Gt173n JVA05lNSVumatT80bDLow7ats8HMzVu32eDepejth9izPkfmzubf/cGYMkl7dfht9+ VkTSucA+HclKies6MxsdkWYwDtk5Y5WVLCMiCJLlMohCCXElFB4jUbKgoAreuqRNUY elm+Wef/bXH1pbzObHQBMwMikpdmdSBUYu8I56YdbPjPZTFmAiX+4gAkCI8XDMpk2v dN+Gx1cJp3CJg== From: Leon Romanovsky To: Jens Axboe , Jason Gunthorpe , Robin Murphy , Joerg Roedel , Will Deacon , Christoph Hellwig , Sagi Grimberg Cc: Keith Busch , Bjorn Helgaas , Logan Gunthorpe , Yishai Hadas , Shameer Kolothum , Kevin Tian , Alex Williamson , Marek Szyprowski , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Andrew Morton , Jonathan Corbet , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-rdma@vger.kernel.org, iommu@lists.linux.dev, linux-nvme@lists.infradead.org, linux-pci@vger.kernel.org, kvm@vger.kernel.org, linux-mm@kvack.org, Randy Dunlap Subject: [PATCH v3 08/17] dma-mapping: add a dma_need_unmap helper Date: Sun, 10 Nov 2024 15:46:55 +0200 Message-ID: X-Mailer: git-send-email 2.47.0 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: Christoph Hellwig Add helper that allows a driver to skip calling dma_unmap_* if the DMA layer can guarantee that they are no-nops. Signed-off-by: Christoph Hellwig Signed-off-by: Leon Romanovsky --- include/linux/dma-mapping.h | 5 +++++ kernel/dma/mapping.c | 18 ++++++++++++++++++ 2 files changed, 23 insertions(+) diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 8074a3b5c807..6906edde505d 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -410,6 +410,7 @@ static inline bool dma_need_sync(struct device *dev, dm= a_addr_t dma_addr) { return dma_dev_need_sync(dev) ? __dma_need_sync(dev, dma_addr) : false; } +bool dma_need_unmap(struct device *dev); #else /* !CONFIG_HAS_DMA || !CONFIG_DMA_NEED_SYNC */ static inline bool dma_dev_need_sync(const struct device *dev) { @@ -435,6 +436,10 @@ static inline bool dma_need_sync(struct device *dev, d= ma_addr_t dma_addr) { return false; } +static inline bool dma_need_unmap(struct device *dev) +{ + return false; +} #endif /* !CONFIG_HAS_DMA || !CONFIG_DMA_NEED_SYNC */ =20 struct page *dma_alloc_pages(struct device *dev, size_t size, diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index 864a1121bf08..ed1c10e5c242 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -442,6 +442,24 @@ bool __dma_need_sync(struct device *dev, dma_addr_t dm= a_addr) } EXPORT_SYMBOL_GPL(__dma_need_sync); =20 +/** + * dma_need_unmap - does this device need dma_unmap_* operations + * @dev: device to check + * + * If this function returns %false, drivers can skip calling dma_unmap_* a= fter + * finishing an I/O. This function must be called after all mappings that= might + * need to be unmapped have been performed. + */ +bool dma_need_unmap(struct device *dev) +{ + if (!dma_map_direct(dev, get_dma_ops(dev))) + return true; + if (!dev->dma_skip_sync) + return true; + return IS_ENABLED(CONFIG_DMA_API_DEBUG); +} +EXPORT_SYMBOL_GPL(dma_need_unmap); + static void dma_setup_need_sync(struct device *dev) { const struct dma_map_ops *ops =3D get_dma_ops(dev); --=20 2.47.0