Messages in this thread | | | Date | Thu, 11 Jun 2015 18:33:02 +0100 | From | Robin Murphy <> | Subject | Re: [PATCH 06/22] iommu: Allocate a default domain for iommu groups |
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Hi Joerg,
On 28/05/15 17:41, Joerg Roedel wrote: > From: Joerg Roedel <jroedel@suse.de> > > 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 <jroedel@suse.de> > --- > 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.
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