linux-kernel - Re: [PATCH 3/3] iommu: Clean up release

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Message-ID: <bc4add1b-8b89-7989-5afb-df6b5338eb3d@arm.com>
Date:   Wed, 22 Jun 2022 08:17:29 +0100
From:   Robin Murphy <robin.murphy@....com>
To:     Baolu Lu <baolu.lu@...ux.intel.com>, joro@...tes.org,
        will@...nel.org
Cc:     iommu@...ts.linux-foundation.org, iommu@...ts.linux.dev,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 3/3] iommu: Clean up release_device checks

On 2022-06-22 02:36, Baolu Lu wrote:
> On 2022/6/21 23:14, Robin Murphy wrote:
>> Since .release_device is now called through per-device ops, any call
>> which gets as far as a driver definitely*is*  for that driver, for a
>> device which has successfully passed .probe_device, so all the checks to
>> that effect are now redundant and can be removed. In the same vein we
>> can also skip freeing fwspecs which are now managed by core code.
> 
> Does this depend on any other series? I didn't see iommu_fwspec_free()
> called in the core code. Or I missed anything?

dev_iommu_free() cleans up param->fwspec directly (see b54240ad4943). 
FWIW the plan is that iommu_fwspec_free() should eventually go away - of 
the remaining uses after this, two are in fact similarly redundant 
already, since there's also a dev_iommu_free() in the probe failure 
path, and the other two should disappear in part 2 of fixing the bus 
probing mess (wherein the of_xlate step gets pulled into 
iommu_probe_device as well, and finally works correctly again).

Cheers,
Robin.

> 
>>
>> Signed-off-by: Robin Murphy<robin.murphy@....com>
>> ---
>>   drivers/iommu/apple-dart.c                  |  3 ---
>>   drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c |  8 +-------
>>   drivers/iommu/arm/arm-smmu/arm-smmu.c       | 14 +++-----------
>>   drivers/iommu/arm/arm-smmu/qcom_iommu.c     | 11 -----------
>>   drivers/iommu/exynos-iommu.c                |  3 ---
>>   drivers/iommu/mtk_iommu.c                   |  5 -----
>>   drivers/iommu/mtk_iommu_v1.c                |  5 -----
>>   drivers/iommu/sprd-iommu.c                  | 11 -----------
>>   drivers/iommu/virtio-iommu.c                |  8 +-------
>>   9 files changed, 5 insertions(+), 63 deletions(-)
> 
> Best regards,
> baolu