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Date:   Tue, 21 Sep 2021 16:49:26 +0100
Message-ID: <87fstyudx5.wl-maz@kernel.org>
From:   Marc Zyngier <maz@kernel.org>
To:     Sven Peter <sven@svenpeter.dev>
Cc:     Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
        iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] iommu/dart: Remove iommu_flush_ops
In-Reply-To: <20210921153934.35647-1-sven@svenpeter.dev>
References: <20210921153934.35647-1-sven@svenpeter.dev>
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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.