From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753226AbcEIWtd (ORCPT ); Mon, 9 May 2016 18:49:33 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48300 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753030AbcEIWtc (ORCPT ); Mon, 9 May 2016 18:49:32 -0400 Date: Mon, 9 May 2016 16:49:28 -0600 From: Alex Williamson To: Eric Auger Cc: eric.auger@st.com, robin.murphy@arm.com, will.deacon@arm.com, joro@8bytes.org, tglx@linutronix.de, jason@lakedaemon.net, marc.zyngier@arm.com, christoffer.dall@linaro.org, linux-arm-kernel@lists.infradead.org, patches@linaro.org, linux-kernel@vger.kernel.org, Bharat.Bhushan@freescale.com, pranav.sawargaonkar@gmail.com, p.fedin@samsung.com, iommu@lists.linux-foundation.org, Jean-Philippe.Brucker@arm.com, julien.grall@arm.com, yehuday@marvell.com Subject: Re: [PATCH v9 2/7] vfio/type1: vfio_find_dma accepting a type argument Message-ID: <20160509164928.518a05a8@t450s.home> In-Reply-To: <1462362858-2925-3-git-send-email-eric.auger@linaro.org> References: <1462362858-2925-1-git-send-email-eric.auger@linaro.org> <1462362858-2925-3-git-send-email-eric.auger@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Mon, 09 May 2016 22:49:31 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 4 May 2016 11:54:13 +0000 Eric Auger wrote: > In our RB-tree we now have slots of different types (USER and RESERVED). > It becomes useful to be able to search for dma slots of a specific type or > any type. This patch proposes an implementation for that modality and also > changes the existing callers using the USER type. > > Signed-off-by: Eric Auger > --- > drivers/vfio/vfio_iommu_type1.c | 63 ++++++++++++++++++++++++++++++++++------- > 1 file changed, 53 insertions(+), 10 deletions(-) > > diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c > index aaf5a6c..2d769d4 100644 > --- a/drivers/vfio/vfio_iommu_type1.c > +++ b/drivers/vfio/vfio_iommu_type1.c > @@ -98,23 +98,64 @@ struct vfio_group { > * into DMA'ble space using the IOMMU > */ > > -static struct vfio_dma *vfio_find_dma(struct vfio_iommu *iommu, > - dma_addr_t start, size_t size) > +/** > + * vfio_find_dma_from_node: looks for a dma slot intersecting a window > + * from a given rb tree node > + * @top: top rb tree node where the search starts (including this node) > + * @start: window start > + * @size: window size > + * @type: window type > + */ > +static struct vfio_dma *vfio_find_dma_from_node(struct rb_node *top, > + dma_addr_t start, size_t size, > + enum vfio_iova_type type) > { > - struct rb_node *node = iommu->dma_list.rb_node; > + struct rb_node *node = top; > + struct vfio_dma *dma; > > while (node) { > - struct vfio_dma *dma = rb_entry(node, struct vfio_dma, node); > - > + dma = rb_entry(node, struct vfio_dma, node); > if (start + size <= dma->iova) > node = node->rb_left; > else if (start >= dma->iova + dma->size) > node = node->rb_right; > else > + break; > + } > + if (!node) > + return NULL; > + > + /* a dma slot intersects our window, check the type also matches */ > + if (type == VFIO_IOVA_ANY || dma->type == type) > + return dma; > + > + /* restart 2 searches skipping the current node */ > + if (start < dma->iova) { > + dma = vfio_find_dma_from_node(node->rb_left, start, > + size, type); > + if (dma) > return dma; > } > + if (start + size > dma->iova + dma->size) > + dma = vfio_find_dma_from_node(node->rb_right, start, > + size, type); It might be nice to split this little bit of trickery out to a separate patch so that you can better explain what it does. It's really not needed until we start creating user-type entries, so it shouldn't hurt bisection. > + return dma; > +} > + > +/** > + * vfio_find_dma: find a dma slot intersecting a given window > + * @iommu: vfio iommu handle > + * @start: window base iova > + * @size: window size > + * @type: window type > + */ > +static struct vfio_dma *vfio_find_dma(struct vfio_iommu *iommu, > + dma_addr_t start, size_t size, > + enum vfio_iova_type type) > +{ > + struct rb_node *top_node = iommu->dma_list.rb_node; > > - return NULL; > + return vfio_find_dma_from_node(top_node, start, size, type); > } > > static void vfio_link_dma(struct vfio_iommu *iommu, struct vfio_dma *new) > @@ -488,19 +529,21 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, > * mappings within the range. > */ > if (iommu->v2) { > - dma = vfio_find_dma(iommu, unmap->iova, 0); > + dma = vfio_find_dma(iommu, unmap->iova, 0, VFIO_IOVA_USER); > if (dma && dma->iova != unmap->iova) { > ret = -EINVAL; > goto unlock; > } > - dma = vfio_find_dma(iommu, unmap->iova + unmap->size - 1, 0); > + dma = vfio_find_dma(iommu, unmap->iova + unmap->size - 1, 0, > + VFIO_IOVA_USER); > if (dma && dma->iova + dma->size != unmap->iova + unmap->size) { > ret = -EINVAL; > goto unlock; > } > } > > - while ((dma = vfio_find_dma(iommu, unmap->iova, unmap->size))) { > + while ((dma = vfio_find_dma(iommu, unmap->iova, unmap->size, > + VFIO_IOVA_USER))) { > if (!iommu->v2 && unmap->iova > dma->iova) > break; > unmapped += dma->size; > @@ -604,7 +647,7 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu, > > mutex_lock(&iommu->lock); > > - if (vfio_find_dma(iommu, iova, size)) { > + if (vfio_find_dma(iommu, iova, size, VFIO_IOVA_ANY)) { > mutex_unlock(&iommu->lock); > return -EEXIST; > }