d38c28dbef
This removes all the notifier de-duplication logic in the driver and relies on the core code to de-duplicate and allocate only one SVA domain per mm per smmu instance. This naturally gives a 1:1 relationship between SVA domain and mmu notifier. It is a significant simplication of the flow, as we end up with a single struct arm_smmu_domain for each MM and the invalidation can then be shifted to properly use the masters list like S1/S2 do. Remove all of the previous mmu_notifier, bond, shared cd, and cd refcount logic entirely. The logic here is tightly wound together with the unusued BTM support. Since the BTM logic requires holding all the iommu_domains in a global ASID xarray it conflicts with the design to have a single SVA domain per PASID, as multiple SMMU instances will need to have different domains. Following patches resolve this by making the ASID xarray per-instance instead of global. However, converting the BTM code over to this methodology requires many changes. Thus, since ARM_SMMU_FEAT_BTM is never enabled, remove the parts of the BTM support for ASID sharing that interact with SVA as well. A followup series is already working on fully enabling the BTM support, that requires iommufd's VIOMMU feature to bring in the KVM's VMID as well. It will come with an already written patch to bring back the ASID sharing using a per-instance ASID xarray. https://lore.kernel.org/linux-iommu/20240208151837.35068-1-shameerali.kolothum.thodi@huawei.com/ https://lore.kernel.org/linux-iommu/26-v6-228e7adf25eb+4155-smmuv3_newapi_p2_jgg@nvidia.com/ Tested-by: Nicolin Chen <nicolinc@nvidia.com> Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Reviewed-by: Nicolin Chen <nicolinc@nvidia.com> Reviewed-by: Michael Shavit <mshavit@google.com> Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/10-v9-5cd718286059+79186-smmuv3_newapi_p2b_jgg@nvidia.com Signed-off-by: Will Deacon <will@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.