Re: [PATCH] iommu/dart: Remove iommu_flush_ops

Marc Zyngier
2021-09-21T15:49:31Z

On Tue, 21 Sep 2021 16:39:34 +0100,
Sven Peter <sven@svenpeter.dev> wrote:
>
> apple_dart_tlb_flush_{all,walk} expect to get a struct apple_dart_domain
> but instead get a struct iommu_domain right now. This breaks those two
> functions and can lead to kernel panics like the one below.
> DART can only invalidate the entire TLB and apple_dart_iotlb_sync will
> already flush everything. There's no need to do that again inside those
> two functions. Let's just drop them.
>
> pci 0000:03:00.0: Removing from iommu group 1
> Unable to handle kernel paging request at virtual address 0000000100000023
> [...]
> Call trace:
> _raw_spin_lock_irqsave+0x54/0xbc
> apple_dart_hw_stream_command.constprop.0+0x2c/0x130
> apple_dart_tlb_flush_all+0x48/0x90
> free_io_pgtable_ops+0x40/0x70
> apple_dart_domain_free+0x2c/0x44
> iommu_group_release+0x68/0xac
> kobject_cleanup+0x4c/0x1fc
> kobject_cleanup+0x14c/0x1fc
> kobject_put+0x64/0x84
> iommu_group_remove_device+0x110/0x180
> iommu_release_device+0x50/0xa0
> [...]
>
> Fixes: 46d1fb072e76b161 ("iommu/dart: Add DART iommu driver")
> Reported-by: Marc Zyngier <maz@kernel.org>
> Signed-off-by: Sven Peter <sven@svenpeter.dev>

Thanks for addressing this so quickly.

Acked-by: Marc Zyngier <maz@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>

M.

--
Without deviation from the norm, progress is not possible.