From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754722AbbFKRdP (ORCPT ); Thu, 11 Jun 2015 13:33:15 -0400 Received: from eu-smtp-delivery-143.mimecast.com ([207.82.80.143]:29955 "EHLO eu-smtp-delivery-143.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751737AbbFKRdM convert rfc822-to-8bit (ORCPT ); Thu, 11 Jun 2015 13:33:12 -0400 Message-ID: <5579C654.80900@arm.com> Date: Thu, 11 Jun 2015 18:33:08 +0100 From: Robin Murphy User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Joerg Roedel , "iommu@lists.linux-foundation.org" CC: Will Deacon , Kukjin Kim , David Woodhouse , Heiko Stuebner , Hiroshi Doyu , Thierry Reding , Alex Williamson , Laurent Pinchart , Oded Gabbay , "jroedel@suse.de" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 06/22] iommu: Allocate a default domain for iommu groups References: <1432831305-11126-1-git-send-email-joro@8bytes.org> <1432831305-11126-7-git-send-email-joro@8bytes.org> In-Reply-To: <1432831305-11126-7-git-send-email-joro@8bytes.org> X-OriginalArrivalTime: 11 Jun 2015 17:33:08.0711 (UTC) FILETIME=[AEA35F70:01D0A46C] X-MC-Unique: iO2TpZhTSW-GsYGjDmJ6sA-1 Content-Type: text/plain; charset=WINDOWS-1252; format=flowed Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Joerg, On 28/05/15 17:41, Joerg Roedel wrote: > From: Joerg Roedel > > The default domain will be used (if supported by the iommu > driver) when the devices in the iommu group are not attached > to any other domain. > > Signed-off-by: Joerg Roedel > --- > drivers/iommu/iommu.c | 32 ++++++++++++++++++++++++++++---- > 1 file changed, 28 insertions(+), 4 deletions(-) > > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c > index d69e0ca..fbfc015 100644 > --- a/drivers/iommu/iommu.c > +++ b/drivers/iommu/iommu.c > @@ -51,6 +51,7 @@ struct iommu_group { > void (*iommu_data_release)(void *iommu_data); > char *name; > int id; > + struct iommu_domain *default_domain; > }; > > struct iommu_device { > @@ -75,6 +76,9 @@ struct iommu_group_attribute iommu_group_attr_##_name = \ > #define to_iommu_group(_kobj) \ > container_of(_kobj, struct iommu_group, kobj) > > +static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus, > + unsigned type); > + > static ssize_t iommu_group_attr_show(struct kobject *kobj, > struct attribute *__attr, char *buf) > { > @@ -137,6 +141,9 @@ static void iommu_group_release(struct kobject *kobj) > ida_remove(&iommu_group_ida, group->id); > mutex_unlock(&iommu_group_mutex); > > + if (group->default_domain) > + iommu_domain_free(group->default_domain); > + > kfree(group->name); > kfree(group); > } > @@ -701,7 +708,18 @@ static struct iommu_group *iommu_group_get_for_pci_dev(struct pci_dev *pdev) > return group; > > /* No shared group found, allocate new */ > - return iommu_group_alloc(); > + group = iommu_group_alloc(); > + if (group) { > + /* > + * Try to allocate a default domain - needs support from the > + * IOMMU driver. > + */ > + group->default_domain = __iommu_domain_alloc(pdev->dev.bus, > + IOMMU_DOMAIN_DMA); > + group->domain = group->default_domain; > + } > + > + return group; > } > > /** > @@ -922,22 +940,28 @@ void iommu_set_fault_handler(struct iommu_domain *domain, > } > EXPORT_SYMBOL_GPL(iommu_set_fault_handler); > > -struct iommu_domain *iommu_domain_alloc(struct bus_type *bus) > +static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus, > + unsigned type) I'd be happier if we passed the iommu_ops in here... > { > struct iommu_domain *domain; > > if (bus == NULL || bus->iommu_ops == NULL) > return NULL; > > - domain = bus->iommu_ops->domain_alloc(IOMMU_DOMAIN_UNMANAGED); > + domain = bus->iommu_ops->domain_alloc(type); > if (!domain) > return NULL; > > domain->ops = bus->iommu_ops; > - domain->type = IOMMU_DOMAIN_UNMANAGED; > + domain->type = type; > > return domain; > } > + > +struct iommu_domain *iommu_domain_alloc(struct bus_type *bus) > +{ ..having pulled them out of the bus here. > + return __iommu_domain_alloc(bus, IOMMU_DOMAIN_UNMANAGED); > +} > EXPORT_SYMBOL_GPL(iommu_domain_alloc); > > void iommu_domain_free(struct iommu_domain *domain) > Even if it's only to symbolically inch us closer to having some other solution for platform bus devices. The SMMU page size debate is one thing, but it's really only a subtle case of the "IOMMU instances" problem. Once there are two different IOMMU drivers in the system each serving a subset of platform devices, how can we make sure the domain allocated here is wrapped in the right driver-private struct? I've had a try with making iommu_ops per-instance, but even that doesn't work in this case. Robin.