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Date:   Tue, 18 Jul 2023 13:38:48 +0200
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Subject: Re: [PATCH drm-next v7 02/13] drm: manager to keep track of GPUs VA
 mappings
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To:     Donald Robson <Donald.Robson@imgtec.com>,
        "corbet@lwn.net" <corbet@lwn.net>,
        "jason@jlekstrand.net" <jason@jlekstrand.net>,
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        "ogabbay@kernel.org" <ogabbay@kernel.org>,
        "boris.brezillon@collabora.com" <boris.brezillon@collabora.com>,
        "Liam.Howlett@oracle.com" <Liam.Howlett@oracle.com>,
        "daniel@ffwll.ch" <daniel@ffwll.ch>,
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References: <20230713170429.2964-1-dakr@redhat.com>
 <20230713170429.2964-3-dakr@redhat.com>
 <f5957892c4fb41becd7084ac93310aae3a6e091a.camel@imgtec.com>
From:   Danilo Krummrich <dakr@redhat.com>
Organization: RedHat
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On 7/17/23 12:00, Donald Robson wrote:
> Hi Danilo,
> The below part of the documentation is out of date now.
> Thanks,
> Donald

Thanks Donald for pointing this out.

If there aren't any further objections in general I will fix up the 
comment and then push the GPUVA Manager parts of the series to 
drm-misc-next.

- Danilo

> 
> On Thu, 2023-07-13 at 19:03 +0200, Danilo Krummrich wrote:
>>
>> +
>> +/**
>> + * DOC: Locking
>> + *
>> + * Generally, the GPU VA manager does not take care of locking itself, it is
>> + * the drivers responsibility to take care about locking. Drivers might want to
>> + * protect the following operations: inserting, removing and iterating
>> + * &drm_gpuva objects as well as generating all kinds of operations, such as
>> + * split / merge or prefetch.
>> + *
>> + * The GPU VA manager also does not take care of the locking of the backing
>> + * &drm_gem_object buffers GPU VA lists by itself; drivers are responsible to
>> + * enforce mutual exclusion using either the GEMs dma_resv lock or alternatively
>> + * a driver specific external lock by setting the @DRM_GPUVA_MANAGER_LOCK_EXTERN
>> + * flag.
>> + *
>> + * For the latter, functions such as drm_gpuva_link() or drm_gpuva_unlink()
>> + * contain lockdep checks to indicate locking issues. For this to work drivers
>> + * must provide (in case the @DRM_GPUVA_MANAGER_LOCK_EXTERN flag is set) their
>> + * external lock with drm_gpuva_manager_set_ext_lock() after initialization.
>> + */
>>