kernel/linux.git - Linux kernel stable tree (mirror)

Age	Commit message (Collapse)	Author	Files	Lines
2023-02-13	xen/grant-dma-iommu: Implement a dummy probe_device() callback	Oleksandr Tyshchenko	1	-2/+9
	Update stub IOMMU driver (which main purpose is to reuse generic IOMMU device-tree bindings by Xen grant DMA-mapping layer on Arm) according to the recent changes done in the following commit 57365a04c921 ("iommu: Move bus setup to IOMMU device registration"). With probe_device() callback being called during IOMMU device registration, the uninitialized callback just leads to the "kernel NULL pointer dereference" issue during boot. Fix that by adding a dummy callback. Looks like the release_device() callback is not mandatory to be implemented as IOMMU framework makes sure that callback is initialized before dereferencing. Reported-by: Viresh Kumar <viresh.kumar@linaro.org> Fixes: 57365a04c921 ("iommu: Move bus setup to IOMMU device registration") Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Tested-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Link: https://lore.kernel.org/r/20230208153649.3604857-1-olekstysh@gmail.com Signed-off-by: Juergen Gross <jgross@suse.com>
2022-06-06	xen/grant-dma-iommu: Introduce stub IOMMU driver	Oleksandr Tyshchenko	1	-0/+78
	In order to reuse generic IOMMU device tree bindings by Xen grant DMA-mapping layer we need to add this stub driver from a fw_devlink perspective (grant-dma-ops cannot be converted into the proper IOMMU driver). Otherwise, just reusing IOMMU bindings (without having a corresponding driver) leads to the deferred probe timeout afterwards, because the IOMMU device never becomes available. This stub driver does nothing except registering empty iommu_ops, the upper layer "of_iommu" will treat this as NO_IOMMU condition and won't return -EPROBE_DEFER. As this driver is quite different from the most hardware IOMMU implementations and only needed in Xen guests, place it in drivers/xen directory. The subsequent commit will make use of it. Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Link: https://lore.kernel.org/r/1654197833-25362-7-git-send-email-olekstysh@gmail.com Signed-off-by: Juergen Gross <jgross@suse.com>