From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 75BC0C433E0 for ; Wed, 13 Jan 2021 12:48:56 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DF4BE2337F for ; Wed, 13 Jan 2021 12:48:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DF4BE2337F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id 85246871B0; Wed, 13 Jan 2021 12:48:55 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ybR9Tsd6P4dr; Wed, 13 Jan 2021 12:48:54 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by hemlock.osuosl.org (Postfix) with ESMTP id 5BE3887196; Wed, 13 Jan 2021 12:48:54 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 3DD84C088B; Wed, 13 Jan 2021 12:48:54 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 75F0BC013A for ; Wed, 13 Jan 2021 12:48:53 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 69AD986422 for ; Wed, 13 Jan 2021 12:48:53 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id xfz_VT1S8uio for ; Wed, 13 Jan 2021 12:48:53 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by fraxinus.osuosl.org (Postfix) with ESMTPS id D5DA885815 for ; Wed, 13 Jan 2021 12:48:52 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id D787F68AFE; Wed, 13 Jan 2021 13:48:47 +0100 (CET) Date: Wed, 13 Jan 2021 13:48:47 +0100 From: Christoph Hellwig To: Claire Chang Subject: Re: [RFC PATCH v3 4/6] swiotlb: Add restricted DMA alloc/free support. Message-ID: <20210113124847.GC1383@lst.de> References: <20210106034124.30560-1-tientzu@chromium.org> <20210106034124.30560-5-tientzu@chromium.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210106034124.30560-5-tientzu@chromium.org> User-Agent: Mutt/1.5.17 (2007-11-01) Cc: heikki.krogerus@linux.intel.com, peterz@infradead.org, benh@kernel.crashing.org, grant.likely@arm.com, paulus@samba.org, frowand.list@gmail.com, mingo@kernel.org, sstabellini@kernel.org, saravanak@google.com, mpe@ellerman.id.au, rafael.j.wysocki@intel.com, hch@lst.de, bgolaszewski@baylibre.com, xen-devel@lists.xenproject.org, treding@nvidia.com, devicetree@vger.kernel.org, will@kernel.org, konrad.wilk@oracle.com, dan.j.williams@intel.com, linuxppc-dev@lists.ozlabs.org, robh+dt@kernel.org, boris.ostrovsky@oracle.com, andriy.shevchenko@linux.intel.com, jgross@suse.com, drinkcat@chromium.org, gregkh@linuxfoundation.org, rdunlap@infradead.org, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, xypron.glpk@gmx.de, robin.murphy@arm.com X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" > +#ifdef CONFIG_SWIOTLB > + if (unlikely(dev->dma_io_tlb_mem)) > + return swiotlb_alloc(dev, size, dma_handle, attrs); > +#endif Another place where the dma_io_tlb_mem is useful to avoid the ifdef. > -phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, phys_addr_t orig_addr, > - size_t mapping_size, size_t alloc_size, > - enum dma_data_direction dir, unsigned long attrs) > +static int swiotlb_tbl_find_free_region(struct device *hwdev, > + dma_addr_t tbl_dma_addr, > + size_t alloc_size, > + unsigned long attrs) > +static void swiotlb_tbl_release_region(struct device *hwdev, int index, > + size_t size) This refactoring should be another prep patch. > +void *swiotlb_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, > + unsigned long attrs) I'd rather have the names convey there are for the per-device bounce buffer in some form. > + struct io_tlb_mem *mem = dev->dma_io_tlb_mem; While we're at it I wonder if the io_tlb is something we could change while we're at it. Maybe replace io_tlb_mem with struct swiotlb and rename the field in struct device to dev_swiotlb? > + int index; > + void *vaddr; > + phys_addr_t tlb_addr; > + > + size = PAGE_ALIGN(size); > + index = swiotlb_tbl_find_free_region(dev, mem->start, size, attrs); > + if (index < 0) > + return NULL; > + > + tlb_addr = mem->start + (index << IO_TLB_SHIFT); > + *dma_handle = phys_to_dma_unencrypted(dev, tlb_addr); > + > + if (!dev_is_dma_coherent(dev)) { > + unsigned long pfn = PFN_DOWN(tlb_addr); > + > + /* remove any dirty cache lines on the kernel alias */ > + arch_dma_prep_coherent(pfn_to_page(pfn), size); Can we hook in somewhat lower level in the dma-direct code so that all the remapping in dma-direct can be reused instead of duplicated? That also becomes important if we want to use non-remapping uncached support, e.g. on mips or x86, or the direct changing of the attributes that Will planned to look into for arm64. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu