From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl1-f197.google.com (mail-pl1-f197.google.com [209.85.214.197]) by kanga.kvack.org (Postfix) with ESMTP id 17D506B7A69 for ; Thu, 6 Dec 2018 09:13:10 -0500 (EST) Received: by mail-pl1-f197.google.com with SMTP id e68so336746plb.3 for ; Thu, 06 Dec 2018 06:13:10 -0800 (PST) Received: from bombadil.infradead.org (bombadil.infradead.org. [2607:7c80:54:e::133]) by mx.google.com with ESMTPS id r18si360491pls.115.2018.12.06.06.13.08 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 06 Dec 2018 06:13:08 -0800 (PST) Date: Thu, 6 Dec 2018 06:10:30 -0800 From: Christoph Hellwig Subject: Re: [PATCH 08/34] powerpc/dma: untangle vio_dma_mapping_ops from dma_iommu_ops Message-ID: <20181206141030.GH29741@infradead.org> References: <20181114082314.8965-1-hch@lst.de> <20181114082314.8965-9-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181114082314.8965-9-hch@lst.de> Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Hellwig Cc: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , linux-arch@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org ping? On Wed, Nov 14, 2018 at 09:22:48AM +0100, Christoph Hellwig wrote: > vio_dma_mapping_ops currently does a lot of indirect calls through > dma_iommu_ops, which not only make the code harder to follow but are > also expensive in the post-spectre world. Unwind the indirect calls > by calling the ppc_iommu_* or iommu_* APIs directly applicable, or > just use the dma_iommu_* methods directly where we can. > > Signed-off-by: Christoph Hellwig > --- > arch/powerpc/include/asm/iommu.h | 1 + > arch/powerpc/kernel/dma-iommu.c | 2 +- > arch/powerpc/platforms/pseries/vio.c | 87 ++++++++++++---------------- > 3 files changed, 38 insertions(+), 52 deletions(-) > > diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h > index 35db0cbc9222..75daa10f31a4 100644 > --- a/arch/powerpc/include/asm/iommu.h > +++ b/arch/powerpc/include/asm/iommu.h > @@ -242,6 +242,7 @@ static inline int __init tce_iommu_bus_notifier_init(void) > } > #endif /* !CONFIG_IOMMU_API */ > > +u64 dma_iommu_get_required_mask(struct device *dev); > int dma_iommu_mapping_error(struct device *dev, dma_addr_t dma_addr); > > #else > diff --git a/arch/powerpc/kernel/dma-iommu.c b/arch/powerpc/kernel/dma-iommu.c > index 2ca6cfaebf65..0613278abf9f 100644 > --- a/arch/powerpc/kernel/dma-iommu.c > +++ b/arch/powerpc/kernel/dma-iommu.c > @@ -92,7 +92,7 @@ int dma_iommu_dma_supported(struct device *dev, u64 mask) > return 1; > } > > -static u64 dma_iommu_get_required_mask(struct device *dev) > +u64 dma_iommu_get_required_mask(struct device *dev) > { > struct iommu_table *tbl = get_iommu_table_base(dev); > u64 mask; > diff --git a/arch/powerpc/platforms/pseries/vio.c b/arch/powerpc/platforms/pseries/vio.c > index 88f1ad1d6309..ea3a9745c812 100644 > --- a/arch/powerpc/platforms/pseries/vio.c > +++ b/arch/powerpc/platforms/pseries/vio.c > @@ -492,7 +492,9 @@ static void *vio_dma_iommu_alloc_coherent(struct device *dev, size_t size, > return NULL; > } > > - ret = dma_iommu_ops.alloc(dev, size, dma_handle, flag, attrs); > + ret = iommu_alloc_coherent(dev, get_iommu_table_base(dev), size, > + dma_handle, dev->coherent_dma_mask, flag, > + dev_to_node(dev)); > if (unlikely(ret == NULL)) { > vio_cmo_dealloc(viodev, roundup(size, PAGE_SIZE)); > atomic_inc(&viodev->cmo.allocs_failed); > @@ -507,8 +509,7 @@ static void vio_dma_iommu_free_coherent(struct device *dev, size_t size, > { > struct vio_dev *viodev = to_vio_dev(dev); > > - dma_iommu_ops.free(dev, size, vaddr, dma_handle, attrs); > - > + iommu_free_coherent(get_iommu_table_base(dev), size, vaddr, dma_handle); > vio_cmo_dealloc(viodev, roundup(size, PAGE_SIZE)); > } > > @@ -518,22 +519,22 @@ static dma_addr_t vio_dma_iommu_map_page(struct device *dev, struct page *page, > unsigned long attrs) > { > struct vio_dev *viodev = to_vio_dev(dev); > - struct iommu_table *tbl; > + struct iommu_table *tbl = get_iommu_table_base(dev); > dma_addr_t ret = IOMMU_MAPPING_ERROR; > > - tbl = get_iommu_table_base(dev); > - if (vio_cmo_alloc(viodev, roundup(size, IOMMU_PAGE_SIZE(tbl)))) { > - atomic_inc(&viodev->cmo.allocs_failed); > - return ret; > - } > - > - ret = dma_iommu_ops.map_page(dev, page, offset, size, direction, attrs); > - if (unlikely(dma_mapping_error(dev, ret))) { > - vio_cmo_dealloc(viodev, roundup(size, IOMMU_PAGE_SIZE(tbl))); > - atomic_inc(&viodev->cmo.allocs_failed); > - } > - > + if (vio_cmo_alloc(viodev, roundup(size, IOMMU_PAGE_SIZE(tbl)))) > + goto out_fail; > + ret = iommu_map_page(dev, tbl, page, offset, size, device_to_mask(dev), > + direction, attrs); > + if (unlikely(ret == IOMMU_MAPPING_ERROR)) > + goto out_deallocate; > return ret; > + > +out_deallocate: > + vio_cmo_dealloc(viodev, roundup(size, IOMMU_PAGE_SIZE(tbl))); > +out_fail: > + atomic_inc(&viodev->cmo.allocs_failed); > + return IOMMU_MAPPING_ERROR; > } > > static void vio_dma_iommu_unmap_page(struct device *dev, dma_addr_t dma_handle, > @@ -542,11 +543,9 @@ static void vio_dma_iommu_unmap_page(struct device *dev, dma_addr_t dma_handle, > unsigned long attrs) > { > struct vio_dev *viodev = to_vio_dev(dev); > - struct iommu_table *tbl; > - > - tbl = get_iommu_table_base(dev); > - dma_iommu_ops.unmap_page(dev, dma_handle, size, direction, attrs); > + struct iommu_table *tbl = get_iommu_table_base(dev); > > + iommu_unmap_page(tbl, dma_handle, size, direction, attrs); > vio_cmo_dealloc(viodev, roundup(size, IOMMU_PAGE_SIZE(tbl))); > } > > @@ -555,34 +554,32 @@ static int vio_dma_iommu_map_sg(struct device *dev, struct scatterlist *sglist, > unsigned long attrs) > { > struct vio_dev *viodev = to_vio_dev(dev); > - struct iommu_table *tbl; > + struct iommu_table *tbl = get_iommu_table_base(dev); > struct scatterlist *sgl; > int ret, count; > size_t alloc_size = 0; > > - tbl = get_iommu_table_base(dev); > for_each_sg(sglist, sgl, nelems, count) > alloc_size += roundup(sgl->length, IOMMU_PAGE_SIZE(tbl)); > > - if (vio_cmo_alloc(viodev, alloc_size)) { > - atomic_inc(&viodev->cmo.allocs_failed); > - return 0; > - } > - > - ret = dma_iommu_ops.map_sg(dev, sglist, nelems, direction, attrs); > - > - if (unlikely(!ret)) { > - vio_cmo_dealloc(viodev, alloc_size); > - atomic_inc(&viodev->cmo.allocs_failed); > - return ret; > - } > + if (vio_cmo_alloc(viodev, alloc_size)) > + goto out_fail; > + ret = ppc_iommu_map_sg(dev, tbl, sglist, nelems, device_to_mask(dev), > + direction, attrs); > + if (unlikely(!ret)) > + goto out_deallocate; > > for_each_sg(sglist, sgl, ret, count) > alloc_size -= roundup(sgl->dma_length, IOMMU_PAGE_SIZE(tbl)); > if (alloc_size) > vio_cmo_dealloc(viodev, alloc_size); > - > return ret; > + > +out_deallocate: > + vio_cmo_dealloc(viodev, alloc_size); > +out_fail: > + atomic_inc(&viodev->cmo.allocs_failed); > + return 0; > } > > static void vio_dma_iommu_unmap_sg(struct device *dev, > @@ -591,30 +588,18 @@ static void vio_dma_iommu_unmap_sg(struct device *dev, > unsigned long attrs) > { > struct vio_dev *viodev = to_vio_dev(dev); > - struct iommu_table *tbl; > + struct iommu_table *tbl = get_iommu_table_base(dev); > struct scatterlist *sgl; > size_t alloc_size = 0; > int count; > > - tbl = get_iommu_table_base(dev); > for_each_sg(sglist, sgl, nelems, count) > alloc_size += roundup(sgl->dma_length, IOMMU_PAGE_SIZE(tbl)); > > - dma_iommu_ops.unmap_sg(dev, sglist, nelems, direction, attrs); > - > + ppc_iommu_unmap_sg(tbl, sglist, nelems, direction, attrs); > vio_cmo_dealloc(viodev, alloc_size); > } > > -static int vio_dma_iommu_dma_supported(struct device *dev, u64 mask) > -{ > - return dma_iommu_ops.dma_supported(dev, mask); > -} > - > -static u64 vio_dma_get_required_mask(struct device *dev) > -{ > - return dma_iommu_ops.get_required_mask(dev); > -} > - > static const struct dma_map_ops vio_dma_mapping_ops = { > .alloc = vio_dma_iommu_alloc_coherent, > .free = vio_dma_iommu_free_coherent, > @@ -623,8 +608,8 @@ static const struct dma_map_ops vio_dma_mapping_ops = { > .unmap_sg = vio_dma_iommu_unmap_sg, > .map_page = vio_dma_iommu_map_page, > .unmap_page = vio_dma_iommu_unmap_page, > - .dma_supported = vio_dma_iommu_dma_supported, > - .get_required_mask = vio_dma_get_required_mask, > + .dma_supported = dma_iommu_mapping_error, > + .get_required_mask = dma_iommu_get_required_mask, > .mapping_error = dma_iommu_mapping_error, > }; > > -- > 2.19.1 > > _______________________________________________ > iommu mailing list > iommu@lists.linux-foundation.org > https://lists.linuxfoundation.org/mailman/listinfo/iommu ---end quoted text---