| Message ID | 23-v3-89830a6c7841+43d-iommu_all_defdom_jgg@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | iommu: Make default_domain's mandatory | expand |
On 6/10/23 3:56 AM, Jason Gunthorpe wrote: > This callback requests the driver to create only a __IOMMU_DOMAIN_PAGING > domain, so it saves a few lines in a lot of drivers needlessly checking > the type. > > More critically, this allows us to sweep out all the > IOMMU_DOMAIN_UNMANAGED and IOMMU_DOMAIN_DMA checks from a lot of the > drivers, simplifying what is going on in the code and ultimately removing > the now-unused special cases in drivers where they did not support > IOMMU_DOMAIN_DMA. > > domain_alloc_paging() should return a struct iommu_domain that is > functionally compatible with ARM_DMA_USE_IOMMU, dma-iommu.c and iommufd. > > Be forwards looking and pass in a 'struct device *' argument. We can > provide this when allocating the default_domain. No drivers will look at > this. I like this idea. :-) > > Tested-by: Steven Price <steven.price@arm.com> > Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> > Tested-by: Nicolin Chen <nicolinc@nvidia.com> > Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> > --- > drivers/iommu/iommu.c | 13 ++++++++++--- > include/linux/iommu.h | 3 +++ > 2 files changed, 13 insertions(+), 3 deletions(-) > > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c > index 0346c05e108438..2cf523ff9c6f55 100644 > --- a/drivers/iommu/iommu.c > +++ b/drivers/iommu/iommu.c > @@ -1985,6 +1985,7 @@ void iommu_set_fault_handler(struct iommu_domain *domain, > EXPORT_SYMBOL_GPL(iommu_set_fault_handler); > > static struct iommu_domain *__iommu_domain_alloc(const struct iommu_ops *ops, > + struct device *dev, > unsigned int type) > { > struct iommu_domain *domain; > @@ -1992,8 +1993,13 @@ static struct iommu_domain *__iommu_domain_alloc(const struct iommu_ops *ops, > > if (alloc_type == IOMMU_DOMAIN_IDENTITY && ops->identity_domain) > return ops->identity_domain; > + else if (type & __IOMMU_DOMAIN_PAGING) { > + domain = ops->domain_alloc_paging(dev); This might be problematic because not all IOMMU drivers implement this callback now. In the missing cases, the code will always result in a null pointer reference issue? > + } else if (ops->domain_alloc) > + domain = ops->domain_alloc(alloc_type); > + else > + return NULL; > > - domain = ops->domain_alloc(alloc_type); > if (!domain) > return NULL; > > @@ -2024,14 +2030,15 @@ __iommu_group_domain_alloc(struct iommu_group *group, unsigned int type) > > lockdep_assert_held(&group->mutex); > > - return __iommu_domain_alloc(dev_iommu_ops(dev), type); > + return __iommu_domain_alloc(dev_iommu_ops(dev), dev, type); > } > > struct iommu_domain *iommu_domain_alloc(const struct bus_type *bus) > { > if (bus == NULL || bus->iommu_ops == NULL) > return NULL; > - return __iommu_domain_alloc(bus->iommu_ops, IOMMU_DOMAIN_UNMANAGED); > + return __iommu_domain_alloc(bus->iommu_ops, NULL, > + IOMMU_DOMAIN_UNMANAGED); Suppose that iommu_domain_alloc() is always called from device drivers where device pointer is always available. Is it possible to convert it to a real device pointer? > } > EXPORT_SYMBOL_GPL(iommu_domain_alloc); > > diff --git a/include/linux/iommu.h b/include/linux/iommu.h > index 49331573f1d1f5..8e4d178c49c417 100644 > --- a/include/linux/iommu.h > +++ b/include/linux/iommu.h > @@ -233,6 +233,8 @@ struct iommu_iotlb_gather { > * struct iommu_ops - iommu ops and capabilities > * @capable: check capability > * @domain_alloc: allocate iommu domain > + * @domain_alloc_paging: Allocate an iommu_domain that can be used for > + * UNMANAGED, DMA, and DMA_FQ domain types. > * @probe_device: Add device to iommu driver handling > * @release_device: Remove device from iommu driver handling > * @probe_finalize: Do final setup work after the device is added to an IOMMU > @@ -264,6 +266,7 @@ struct iommu_ops { > > /* Domain allocation and freeing by the iommu driver */ > struct iommu_domain *(*domain_alloc)(unsigned iommu_domain_type); > + struct iommu_domain *(*domain_alloc_paging)(struct device *dev); > > struct iommu_device *(*probe_device)(struct device *dev); > void (*release_device)(struct device *dev); Best regards, baolu
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 0346c05e108438..2cf523ff9c6f55 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -1985,6 +1985,7 @@ void iommu_set_fault_handler(struct iommu_domain *domain, EXPORT_SYMBOL_GPL(iommu_set_fault_handler); static struct iommu_domain *__iommu_domain_alloc(const struct iommu_ops *ops, + struct device *dev, unsigned int type) { struct iommu_domain *domain; @@ -1992,8 +1993,13 @@ static struct iommu_domain *__iommu_domain_alloc(const struct iommu_ops *ops, if (alloc_type == IOMMU_DOMAIN_IDENTITY && ops->identity_domain) return ops->identity_domain; + else if (type & __IOMMU_DOMAIN_PAGING) { + domain = ops->domain_alloc_paging(dev); + } else if (ops->domain_alloc) + domain = ops->domain_alloc(alloc_type); + else + return NULL; - domain = ops->domain_alloc(alloc_type); if (!domain) return NULL; @@ -2024,14 +2030,15 @@ __iommu_group_domain_alloc(struct iommu_group *group, unsigned int type) lockdep_assert_held(&group->mutex); - return __iommu_domain_alloc(dev_iommu_ops(dev), type); + return __iommu_domain_alloc(dev_iommu_ops(dev), dev, type); } struct iommu_domain *iommu_domain_alloc(const struct bus_type *bus) { if (bus == NULL || bus->iommu_ops == NULL) return NULL; - return __iommu_domain_alloc(bus->iommu_ops, IOMMU_DOMAIN_UNMANAGED); + return __iommu_domain_alloc(bus->iommu_ops, NULL, + IOMMU_DOMAIN_UNMANAGED); } EXPORT_SYMBOL_GPL(iommu_domain_alloc); diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 49331573f1d1f5..8e4d178c49c417 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -233,6 +233,8 @@ struct iommu_iotlb_gather { * struct iommu_ops - iommu ops and capabilities * @capable: check capability * @domain_alloc: allocate iommu domain + * @domain_alloc_paging: Allocate an iommu_domain that can be used for + * UNMANAGED, DMA, and DMA_FQ domain types. * @probe_device: Add device to iommu driver handling * @release_device: Remove device from iommu driver handling * @probe_finalize: Do final setup work after the device is added to an IOMMU @@ -264,6 +266,7 @@ struct iommu_ops { /* Domain allocation and freeing by the iommu driver */ struct iommu_domain *(*domain_alloc)(unsigned iommu_domain_type); + struct iommu_domain *(*domain_alloc_paging)(struct device *dev); struct iommu_device *(*probe_device)(struct device *dev); void (*release_device)(struct device *dev);