From patchwork Fri Nov 6 17:00:28 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Logan Gunthorpe X-Patchwork-Id: 1395755 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=linux-pci-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=deltatee.com Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=deltatee.com header.i=@deltatee.com header.a=rsa-sha256 header.s=20200525 header.b=rY/cLrzC; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4CSRW36mBDz9sVX for ; Sat, 7 Nov 2020 04:01:35 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727358AbgKFRBX (ORCPT ); Fri, 6 Nov 2020 12:01:23 -0500 Received: from ale.deltatee.com ([204.191.154.188]:57816 "EHLO ale.deltatee.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727521AbgKFRBD (ORCPT ); Fri, 6 Nov 2020 12:01:03 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=deltatee.com; s=20200525; h=Subject:Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=VLOfKPK+Zi2nLbPxB2RMFlp3vuqLnc2Fa5/3XSZoOkg=; b=rY/cLrzCiAzbq4ZIlHRpYwdkI6 WqQYPcJFEOLZTMtY7YzVS5nKxRMAYBSmO1PqPdFS7hIq5M1Zx9aqk8kudHNloty/eBUsDetBOGtwo WVPRcquq607bgfsQZmvaozqmWVbkFzwBmFJ0wbhoE+FZnFUmVtHa+NcgtRHa0Vybx1th5NikUPGc0 NXAtdqGsC5Ygfn7zy1iJg1it8qHpJvu85FILHZZJI1gBJ9gEZiFRnzN2XQOsl33s0J1c97PMr5oGv x2iFNr6WpFpmBb0KHX1xBldnhJBHO0Lc5vsS0jaQZqtjXpLUOMoybdNw6MqkZS8xtZ8+DxVTO/Y3b /VpCw86A==; Received: from cgy1-donard.priv.deltatee.com ([172.16.1.31]) by ale.deltatee.com with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1kb56i-0002PV-Cj; Fri, 06 Nov 2020 10:01:02 -0700 Received: from gunthorp by cgy1-donard.priv.deltatee.com with local (Exim 4.92) (envelope-from ) id 1kb56U-0004t8-Sl; Fri, 06 Nov 2020 10:00:46 -0700 From: Logan Gunthorpe To: linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, linux-pci@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org Cc: Stephen Bates , Christoph Hellwig , Dan Williams , Jason Gunthorpe , =?utf-8?q?Christian_K=C3=B6nig?= , Ira Weiny , John Hubbard , Don Dutile , Matthew Wilcox , Daniel Vetter , Logan Gunthorpe Date: Fri, 6 Nov 2020 10:00:28 -0700 Message-Id: <20201106170036.18713-8-logang@deltatee.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20201106170036.18713-1-logang@deltatee.com> References: <20201106170036.18713-1-logang@deltatee.com> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 172.16.1.31 X-SA-Exim-Rcpt-To: linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-pci@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org, sbates@raithlin.com, hch@lst.de, jgg@ziepe.ca, christian.koenig@amd.com, dan.j.williams@intel.com, iweiny@intel.com, jhubbard@nvidia.com, ddutile@redhat.com, willy@infradead.org, daniel.vetter@ffwll.ch, logang@deltatee.com X-SA-Exim-Mail-From: gunthorp@deltatee.com X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on ale.deltatee.com X-Spam-Level: X-Spam-Status: No, score=-8.5 required=5.0 tests=ALL_TRUSTED,BAYES_00, GREYLIST_ISWHITE,MYRULES_FREE,MYRULES_NO_TEXT autolearn=ham autolearn_force=no version=3.4.2 Subject: [RFC PATCH 07/15] iommu/dma: Support PCI P2PDMA pages in dma-iommu map_sg X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org When a PCI P2PDMA page is seen, set the IOVA length of the segment to zero so that it is not mapped into the IOVA. Then, in finalise_sg(), apply the appropriate bus address to the segment. The IOVA is not created if the scatterlist only consists of P2PDMA pages. Similar to dma-direct, DMA_ATTR_P2PDMA is used to indicate caller support seeing the high bit of the dma_length is used as a flag to indicate P2PDMA segments. On unmap, P2PDMA segments are skipped over when determining the start and end IOVA addresses. With this change, the flags variable in the dma_map_ops is set to DMA_F_PCI_P2PDMA_SUPPORTED to indicate support for P2PDMA pages. Signed-off-by: Logan Gunthorpe --- drivers/iommu/dma-iommu.c | 63 ++++++++++++++++++++++++++++++++------- 1 file changed, 53 insertions(+), 10 deletions(-) diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 5591d6593583..1c8402474376 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include #include @@ -872,13 +873,16 @@ static void iommu_dma_unmap_page(struct device *dev, dma_addr_t dma_handle, * segment's start address to avoid concatenating across one. */ static int __finalise_sg(struct device *dev, struct scatterlist *sg, int nents, - dma_addr_t dma_addr) + dma_addr_t dma_addr, unsigned long attrs) { struct scatterlist *s, *cur = sg; unsigned long seg_mask = dma_get_seg_boundary(dev); unsigned int cur_len = 0, max_len = dma_get_max_seg_size(dev); int i, count = 0; + if (attrs & DMA_ATTR_P2PDMA && max_len >= SG_P2PDMA_FLAG) + max_len = SG_P2PDMA_FLAG - 1; + /* * The Intel graphic driver is used to assume that the returned * sg list is not combound. This blocks the efforts of converting @@ -917,6 +921,19 @@ static int __finalise_sg(struct device *dev, struct scatterlist *sg, int nents, sg_dma_address(s) = DMA_MAPPING_ERROR; sg_dma_len(s) = 0; + if (is_pci_p2pdma_page(sg_page(s)) && !s_iova_len) { + if (i > 0) + cur = sg_next(cur); + + sg_dma_address(cur) = sg_phys(s) + s->offset - + pci_p2pdma_bus_offset(sg_page(s)); + sg_dma_len(cur) = s->length | SG_P2PDMA_FLAG; + + count++; + cur_len = 0; + continue; + } + /* * Now fill in the real DMA data. If... * - there is a valid output segment to append to @@ -1013,11 +1030,12 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg, struct iommu_dma_cookie *cookie = domain->iova_cookie; struct iova_domain *iovad = &cookie->iovad; struct scatterlist *s, *prev = NULL; + struct dev_pagemap *pgmap = NULL; int prot = dma_info_to_prot(dir, dev_is_dma_coherent(dev), attrs); dma_addr_t iova; size_t iova_len = 0; unsigned long mask = dma_get_seg_boundary(dev); - int i; + int i, map = -1; if (unlikely(iommu_dma_deferred_attach(dev, domain))) return 0; @@ -1045,6 +1063,21 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg, s_length = iova_align(iovad, s_length + s_iova_off); s->length = s_length; + if (is_pci_p2pdma_page(sg_page(s))) { + if (sg_page(s)->pgmap != pgmap) { + pgmap = sg_page(s)->pgmap; + map = pci_p2pdma_should_map_bus(dev, pgmap); + } + + if (map < 0 || !(attrs & DMA_ATTR_P2PDMA)) + goto out_restore_sg; + + if (map) { + s->length = 0; + continue; + } + } + /* * Due to the alignment of our single IOVA allocation, we can * depend on these assumptions about the segment boundary mask: @@ -1067,6 +1100,9 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg, prev = s; } + if (!iova_len) + return __finalise_sg(dev, sg, nents, 0, attrs); + iova = iommu_dma_alloc_iova(domain, iova_len, dma_get_mask(dev), dev); if (!iova) goto out_restore_sg; @@ -1078,7 +1114,7 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg, if (iommu_map_sg_atomic(domain, iova, sg, nents, prot) < iova_len) goto out_free_iova; - return __finalise_sg(dev, sg, nents, iova); + return __finalise_sg(dev, sg, nents, iova, attrs); out_free_iova: iommu_dma_free_iova(cookie, iova, iova_len, NULL); @@ -1090,7 +1126,7 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg, static void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction dir, unsigned long attrs) { - dma_addr_t start, end; + dma_addr_t end, start = DMA_MAPPING_ERROR; struct scatterlist *tmp; int i; @@ -1106,14 +1142,20 @@ static void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg, * The scatterlist segments are mapped into a single * contiguous IOVA allocation, so this is incredibly easy. */ - start = sg_dma_address(sg); - for_each_sg(sg_next(sg), tmp, nents - 1, i) { - if (sg_dma_len(tmp) == 0) + for_each_sg(sg, tmp, nents, i) { + if ((attrs & DMA_ATTR_P2PDMA) && sg_dma_is_p2pdma(tmp)) + continue; + if (sg_dma_p2pdma_len(tmp) == 0) break; - sg = tmp; + + if (start == DMA_MAPPING_ERROR) + start = sg_dma_address(tmp); + + end = sg_dma_address(tmp) + sg_dma_len(tmp); } - end = sg_dma_address(sg) + sg_dma_len(sg); - __iommu_dma_unmap(dev, start, end - start); + + if (start != DMA_MAPPING_ERROR) + __iommu_dma_unmap(dev, start, end - start); } static dma_addr_t iommu_dma_map_resource(struct device *dev, phys_addr_t phys, @@ -1334,6 +1376,7 @@ static unsigned long iommu_dma_get_merge_boundary(struct device *dev) } static const struct dma_map_ops iommu_dma_ops = { + .flags = DMA_F_PCI_P2PDMA_SUPPORTED, .alloc = iommu_dma_alloc, .free = iommu_dma_free, .alloc_pages = dma_common_alloc_pages,