The goal of the Generic Kernel Image (GKI) effort is to have a common image that works across multiple Android devices. This involves generating a kernel image that has core features integrated into it, while SoC specific functionality can be added to the kernel for the device as a module.
Along with modularizing IOMMU drivers, this also means building the io-pgtable code as modules, which allows for SoC vendors to only include the io-pgtable implementations that they use. For example, GKI for arm64 must include support for both the IOMMU ARM LPAE/V7S formats at the moment. Having the code for both formats as modules allows SoC vendors to only provide the page table format that they use, along with their IOMMU driver. Modularizing both io-pgtable.c, as well as the io-pgtable-arm[-v7s].c files, works out rather nicely, as the main interface that clients use to interact with the page tables is already exported (i.e. alloc_io_pgtable_ops and free_io_pgtable_ops). It also makes it so that neither the io-pgtable-arm[-v7s] modules or the io-pgtable modules can be unloaded without unloading the IOMMU driver, which can only happen when there aren't any references to the IOMMU driver module. Thanks in advance for the feedback, Isaac J. Manjarres Isaac J. Manjarres (3): iommu/io-pgtable-arm: Prepare for modularization iommu/io-pgtable: Prepare for modularization iommu/io-pgtable: Allow building as a module drivers/iommu/Kconfig | 6 +++--- drivers/iommu/io-pgtable-arm-v7s.c | 4 ++++ drivers/iommu/io-pgtable-arm.c | 8 ++++++++ drivers/iommu/io-pgtable.c | 7 +++++-- 4 files changed, 20 insertions(+), 5 deletions(-) -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project
