From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754117AbcDTNNG (ORCPT ); Wed, 20 Apr 2016 09:13:06 -0400 Received: from foss.arm.com ([217.140.101.70]:47543 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752945AbcDTNND (ORCPT ); Wed, 20 Apr 2016 09:13:03 -0400 Subject: Re: [PATCH v7 05/10] iommu/dma-reserved-iommu: reserved binding rb-tree and helpers To: Eric Auger , eric.auger@st.com, alex.williamson@redhat.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 References: <1461084994-2355-1-git-send-email-eric.auger@linaro.org> <1461084994-2355-6-git-send-email-eric.auger@linaro.org> Cc: 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 From: Robin Murphy Message-ID: <5717805A.3070602@arm.com> Date: Wed, 20 Apr 2016 14:12:58 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <1461084994-2355-6-git-send-email-eric.auger@linaro.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 19/04/16 17:56, Eric Auger wrote: > we will need to track which host physical addresses are mapped to > reserved IOVA. In that prospect we introduce a new RB tree indexed > by physical address. This RB tree only is used for reserved IOVA > bindings. > > It is expected this RB tree will contain very few bindings. Sounds like a good reason in favour of using a list, and thus having rather less code here ;) > Those > generally correspond to single page mapping one MSI frame (GICv2m > frame or ITS GITS_TRANSLATER frame). > > Signed-off-by: Eric Auger > > --- > v5 -> v6: > - add comment about @d->reserved_lock to be held > > v3 -> v4: > - that code was formerly in "iommu/arm-smmu: add a reserved binding RB tree" > --- > drivers/iommu/dma-reserved-iommu.c | 63 ++++++++++++++++++++++++++++++++++++++ > 1 file changed, 63 insertions(+) > > diff --git a/drivers/iommu/dma-reserved-iommu.c b/drivers/iommu/dma-reserved-iommu.c > index 2562af0..f6fa18e 100644 > --- a/drivers/iommu/dma-reserved-iommu.c > +++ b/drivers/iommu/dma-reserved-iommu.c > @@ -23,6 +23,69 @@ struct reserved_iova_domain { > int prot; /* iommu protection attributes to be obeyed */ > }; > > +struct iommu_reserved_binding { > + struct kref kref; > + struct rb_node node; > + struct iommu_domain *domain; Hang on, the tree these are in is already embedded in a domain. Ergo we can't look them up without first knowing the domain they belong to, so what purpose does this guy serve? Robin. > + phys_addr_t addr; > + dma_addr_t iova; > + size_t size; > +}; > + > +/* Reserved binding RB-tree manipulation */ > + > +/* @d->reserved_lock must be held */ > +static struct iommu_reserved_binding *find_reserved_binding( > + struct iommu_domain *d, > + phys_addr_t start, size_t size) > +{ > + struct rb_node *node = d->reserved_binding_list.rb_node; > + > + while (node) { > + struct iommu_reserved_binding *binding = > + rb_entry(node, struct iommu_reserved_binding, node); > + > + if (start + size <= binding->addr) > + node = node->rb_left; > + else if (start >= binding->addr + binding->size) > + node = node->rb_right; > + else > + return binding; > + } > + > + return NULL; > +} > + > +/* @d->reserved_lock must be held */ > +static void link_reserved_binding(struct iommu_domain *d, > + struct iommu_reserved_binding *new) > +{ > + struct rb_node **link = &d->reserved_binding_list.rb_node; > + struct rb_node *parent = NULL; > + struct iommu_reserved_binding *binding; > + > + while (*link) { > + parent = *link; > + binding = rb_entry(parent, struct iommu_reserved_binding, > + node); > + > + if (new->addr + new->size <= binding->addr) > + link = &(*link)->rb_left; > + else > + link = &(*link)->rb_right; > + } > + > + rb_link_node(&new->node, parent, link); > + rb_insert_color(&new->node, &d->reserved_binding_list); > +} > + > +/* @d->reserved_lock must be held */ > +static void unlink_reserved_binding(struct iommu_domain *d, > + struct iommu_reserved_binding *old) > +{ > + rb_erase(&old->node, &d->reserved_binding_list); > +} > + > int iommu_alloc_reserved_iova_domain(struct iommu_domain *domain, > dma_addr_t iova, size_t size, int prot, > unsigned long order) > From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robin Murphy Subject: Re: [PATCH v7 05/10] iommu/dma-reserved-iommu: reserved binding rb-tree and helpers Date: Wed, 20 Apr 2016 14:12:58 +0100 Message-ID: <5717805A.3070602@arm.com> References: <1461084994-2355-1-git-send-email-eric.auger@linaro.org> <1461084994-2355-6-git-send-email-eric.auger@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1461084994-2355-6-git-send-email-eric.auger-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Eric Auger , eric.auger-qxv4g6HH51o@public.gmane.org, alex.williamson-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, will.deacon-5wv7dgnIgG8@public.gmane.org, joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org, tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org, jason-NLaQJdtUoK4Be96aLqz0jA@public.gmane.org, marc.zyngier-5wv7dgnIgG8@public.gmane.org, christoffer.dall-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org Cc: julien.grall-5wv7dgnIgG8@public.gmane.org, patches-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, p.fedin-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, pranav.sawargaonkar-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org List-Id: iommu@lists.linux-foundation.org On 19/04/16 17:56, Eric Auger wrote: > we will need to track which host physical addresses are mapped to > reserved IOVA. In that prospect we introduce a new RB tree indexed > by physical address. This RB tree only is used for reserved IOVA > bindings. > > It is expected this RB tree will contain very few bindings. Sounds like a good reason in favour of using a list, and thus having rather less code here ;) > Those > generally correspond to single page mapping one MSI frame (GICv2m > frame or ITS GITS_TRANSLATER frame). > > Signed-off-by: Eric Auger > > --- > v5 -> v6: > - add comment about @d->reserved_lock to be held > > v3 -> v4: > - that code was formerly in "iommu/arm-smmu: add a reserved binding RB tree" > --- > drivers/iommu/dma-reserved-iommu.c | 63 ++++++++++++++++++++++++++++++++++++++ > 1 file changed, 63 insertions(+) > > diff --git a/drivers/iommu/dma-reserved-iommu.c b/drivers/iommu/dma-reserved-iommu.c > index 2562af0..f6fa18e 100644 > --- a/drivers/iommu/dma-reserved-iommu.c > +++ b/drivers/iommu/dma-reserved-iommu.c > @@ -23,6 +23,69 @@ struct reserved_iova_domain { > int prot; /* iommu protection attributes to be obeyed */ > }; > > +struct iommu_reserved_binding { > + struct kref kref; > + struct rb_node node; > + struct iommu_domain *domain; Hang on, the tree these are in is already embedded in a domain. Ergo we can't look them up without first knowing the domain they belong to, so what purpose does this guy serve? Robin. > + phys_addr_t addr; > + dma_addr_t iova; > + size_t size; > +}; > + > +/* Reserved binding RB-tree manipulation */ > + > +/* @d->reserved_lock must be held */ > +static struct iommu_reserved_binding *find_reserved_binding( > + struct iommu_domain *d, > + phys_addr_t start, size_t size) > +{ > + struct rb_node *node = d->reserved_binding_list.rb_node; > + > + while (node) { > + struct iommu_reserved_binding *binding = > + rb_entry(node, struct iommu_reserved_binding, node); > + > + if (start + size <= binding->addr) > + node = node->rb_left; > + else if (start >= binding->addr + binding->size) > + node = node->rb_right; > + else > + return binding; > + } > + > + return NULL; > +} > + > +/* @d->reserved_lock must be held */ > +static void link_reserved_binding(struct iommu_domain *d, > + struct iommu_reserved_binding *new) > +{ > + struct rb_node **link = &d->reserved_binding_list.rb_node; > + struct rb_node *parent = NULL; > + struct iommu_reserved_binding *binding; > + > + while (*link) { > + parent = *link; > + binding = rb_entry(parent, struct iommu_reserved_binding, > + node); > + > + if (new->addr + new->size <= binding->addr) > + link = &(*link)->rb_left; > + else > + link = &(*link)->rb_right; > + } > + > + rb_link_node(&new->node, parent, link); > + rb_insert_color(&new->node, &d->reserved_binding_list); > +} > + > +/* @d->reserved_lock must be held */ > +static void unlink_reserved_binding(struct iommu_domain *d, > + struct iommu_reserved_binding *old) > +{ > + rb_erase(&old->node, &d->reserved_binding_list); > +} > + > int iommu_alloc_reserved_iova_domain(struct iommu_domain *domain, > dma_addr_t iova, size_t size, int prot, > unsigned long order) > From mboxrd@z Thu Jan 1 00:00:00 1970 From: robin.murphy@arm.com (Robin Murphy) Date: Wed, 20 Apr 2016 14:12:58 +0100 Subject: [PATCH v7 05/10] iommu/dma-reserved-iommu: reserved binding rb-tree and helpers In-Reply-To: <1461084994-2355-6-git-send-email-eric.auger@linaro.org> References: <1461084994-2355-1-git-send-email-eric.auger@linaro.org> <1461084994-2355-6-git-send-email-eric.auger@linaro.org> Message-ID: <5717805A.3070602@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 19/04/16 17:56, Eric Auger wrote: > we will need to track which host physical addresses are mapped to > reserved IOVA. In that prospect we introduce a new RB tree indexed > by physical address. This RB tree only is used for reserved IOVA > bindings. > > It is expected this RB tree will contain very few bindings. Sounds like a good reason in favour of using a list, and thus having rather less code here ;) > Those > generally correspond to single page mapping one MSI frame (GICv2m > frame or ITS GITS_TRANSLATER frame). > > Signed-off-by: Eric Auger > > --- > v5 -> v6: > - add comment about @d->reserved_lock to be held > > v3 -> v4: > - that code was formerly in "iommu/arm-smmu: add a reserved binding RB tree" > --- > drivers/iommu/dma-reserved-iommu.c | 63 ++++++++++++++++++++++++++++++++++++++ > 1 file changed, 63 insertions(+) > > diff --git a/drivers/iommu/dma-reserved-iommu.c b/drivers/iommu/dma-reserved-iommu.c > index 2562af0..f6fa18e 100644 > --- a/drivers/iommu/dma-reserved-iommu.c > +++ b/drivers/iommu/dma-reserved-iommu.c > @@ -23,6 +23,69 @@ struct reserved_iova_domain { > int prot; /* iommu protection attributes to be obeyed */ > }; > > +struct iommu_reserved_binding { > + struct kref kref; > + struct rb_node node; > + struct iommu_domain *domain; Hang on, the tree these are in is already embedded in a domain. Ergo we can't look them up without first knowing the domain they belong to, so what purpose does this guy serve? Robin. > + phys_addr_t addr; > + dma_addr_t iova; > + size_t size; > +}; > + > +/* Reserved binding RB-tree manipulation */ > + > +/* @d->reserved_lock must be held */ > +static struct iommu_reserved_binding *find_reserved_binding( > + struct iommu_domain *d, > + phys_addr_t start, size_t size) > +{ > + struct rb_node *node = d->reserved_binding_list.rb_node; > + > + while (node) { > + struct iommu_reserved_binding *binding = > + rb_entry(node, struct iommu_reserved_binding, node); > + > + if (start + size <= binding->addr) > + node = node->rb_left; > + else if (start >= binding->addr + binding->size) > + node = node->rb_right; > + else > + return binding; > + } > + > + return NULL; > +} > + > +/* @d->reserved_lock must be held */ > +static void link_reserved_binding(struct iommu_domain *d, > + struct iommu_reserved_binding *new) > +{ > + struct rb_node **link = &d->reserved_binding_list.rb_node; > + struct rb_node *parent = NULL; > + struct iommu_reserved_binding *binding; > + > + while (*link) { > + parent = *link; > + binding = rb_entry(parent, struct iommu_reserved_binding, > + node); > + > + if (new->addr + new->size <= binding->addr) > + link = &(*link)->rb_left; > + else > + link = &(*link)->rb_right; > + } > + > + rb_link_node(&new->node, parent, link); > + rb_insert_color(&new->node, &d->reserved_binding_list); > +} > + > +/* @d->reserved_lock must be held */ > +static void unlink_reserved_binding(struct iommu_domain *d, > + struct iommu_reserved_binding *old) > +{ > + rb_erase(&old->node, &d->reserved_binding_list); > +} > + > int iommu_alloc_reserved_iova_domain(struct iommu_domain *domain, > dma_addr_t iova, size_t size, int prot, > unsigned long order) >