[PATCH v7 22/24] iommu: Add ops->domain_alloc_paging()
From: Jason Gunthorpe <jgg@nvidia.com>
Date: 2023-08-23 16:48:06
Also in:
linux-arm-kernel, linux-arm-msm, linux-iommu, linux-mediatek, linux-rockchip, linux-s390, linux-samsung-soc, linux-sunxi, linux-tegra
Subsystem:
iommu subsystem, the rest · Maintainers:
Joerg Roedel, Will Deacon, Linus Torvalds
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. Tested-by: Steven Price <steven.price@arm.com> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Tested-by: Nicolin Chen <redacted> Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> --- drivers/iommu/iommu.c | 17 ++++++++++++++--- include/linux/iommu.h | 3 +++ 2 files changed, 17 insertions(+), 3 deletions(-)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 568dec45a06954..c5d8cf48a99332 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c@@ -2041,6 +2041,7 @@ 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;
@@ -2048,8 +2049,13 @@ 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 && ops->domain_alloc_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;
@@ -2074,14 +2080,19 @@ static struct iommu_domain *__iommu_domain_alloc(const struct iommu_ops *ops, static struct iommu_domain * __iommu_group_domain_alloc(struct iommu_group *group, unsigned int type) { - return __iommu_domain_alloc(group_iommu_ops(group), type); + struct device *dev = + list_first_entry(&group->devices, struct group_device, list) + ->dev; + + return __iommu_domain_alloc(group_iommu_ops(group), 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 c3d2e79076ffab..319bdc8328b407 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h@@ -239,6 +239,8 @@ struct iommu_iotlb_gather { * use. The information type is one of enum iommu_hw_info_type defined * in include/uapi/linux/iommufd.h. * @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
@@ -271,6 +273,7 @@ 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);
--
2.41.0