Re: [PATCH v3 12/18] iommu: Add iommu_at[de]tach_device_shared() for multi-device groups

Subject: Re: [PATCH v3 12/18] iommu: Add iommu_at[de]tach_device_shared() for multi-device groups
From: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Date: Mon, 6 Dec 2021 06:43:31 -0800
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>, Joerg Roedel <joro@xxxxxxxxxx>, Alex Williamson <alex.williamson@xxxxxxxxxx>, Bjorn Helgaas <bhelgaas@xxxxxxxxxx>, Jason Gunthorpe <jgg@xxxxxxxxxx>, Christoph Hellwig <hch@xxxxxxxxxxxxx>, Kevin Tian <kevin.tian@xxxxxxxxx>, Ashok Raj <ashok.raj@xxxxxxxxx>, Will Deacon <will@xxxxxxxxxx>, Robin Murphy <robin.murphy@xxxxxxx>, Dan Williams <dan.j.williams@xxxxxxxxx>, rafael@xxxxxxxxxx, Diana Craciun <diana.craciun@xxxxxxxxxxx>, Cornelia Huck <cohuck@xxxxxxxxxx>, Eric Auger <eric.auger@xxxxxxxxxx>, Liu Yi L <yi.l.liu@xxxxxxxxx>, Jacob jun Pan <jacob.jun.pan@xxxxxxxxx>, Chaitanya Kulkarni <kch@xxxxxxxxxx>, Stuart Yoder <stuyoder@xxxxxxxxx>, Laurentiu Tudor <laurentiu.tudor@xxxxxxx>, Thierry Reding <thierry.reding@xxxxxxxxx>, David Airlie <airlied@xxxxxxxx>, Daniel Vetter <daniel@xxxxxxxx>, Jonathan Hunter <jonathanh@xxxxxxxxxx>, Li Yang <leoyang.li@xxxxxxx>, Dmitry Osipenko <digetx@xxxxxxxxx>, iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx, linux-pci@xxxxxxxxxxxxxxx, kvm@xxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx
In-reply-to: <20211206015903.88687-13-baolu.lu@linux.intel.com>
References: <20211206015903.88687-1-baolu.lu@linux.intel.com> <20211206015903.88687-13-baolu.lu@linux.intel.com>

The new helpers really could use a kerneldoc comment.
Also no need for the refcount_t with it's atomic operations for
attach_cnt either.

Follow-Ups:
- Re: [PATCH v3 12/18] iommu: Add iommu_at[de]tach_device_shared() for multi-device groups
  - From: Lu Baolu

References:
- [PATCH v3 00/18] Fix BUG_ON in vfio_iommu_group_notifier()
  - From: Lu Baolu
- [PATCH v3 12/18] iommu: Add iommu_at[de]tach_device_shared() for multi-device groups
  - From: Lu Baolu