From: Jonathan Marek <jonathan@marek.ca>
To: Christoph Hellwig <hch@infradead.org>
Cc: David Airlie <airlied@linux.ie>,
freedreno@lists.freedesktop.org,
open list <linux-kernel@vger.kernel.org>,
"open list:DRM DRIVER FOR MSM ADRENO GPU"
<dri-devel@lists.freedesktop.org>,
"open list:DRM DRIVER FOR MSM ADRENO GPU"
<linux-arm-msm@vger.kernel.org>, Sean Paul <sean@poorly.run>
Subject: Re: [PATCH 2/3] drm/msm: add DRM_MSM_GEM_SYNC_CACHE for non-coherent cache maintenance
Date: Fri, 2 Oct 2020 08:46:35 -0400 [thread overview]
Message-ID: <b22fb797-67b0-a912-1d23-2b47c9a9e674@marek.ca> (raw)
In-Reply-To: <20201002075321.GA7547@infradead.org>
On 10/2/20 3:53 AM, Christoph Hellwig wrote:
>> @@ -8,6 +8,7 @@
>> #include <linux/shmem_fs.h>
>> #include <linux/dma-buf.h>
>> #include <linux/pfn_t.h>
>> +#include <linux/dma-noncoherent.h>
>
> NAK, dma-noncoherent.h is not for driver use. And will in fact go
> away in 5.10.
>
Not actually used, so can be removed.
>>
>> #include <drm/drm_prime.h>
>>
>> @@ -808,6 +809,20 @@ int msm_gem_cpu_fini(struct drm_gem_object *obj)
>> return 0;
>> }
>>
>> +void msm_gem_sync_cache(struct drm_gem_object *obj, uint32_t flags,
>> + size_t range_start, size_t range_end)
>> +{
>> + struct msm_gem_object *msm_obj = to_msm_bo(obj);
>> +
>> + /* TODO: sync only the required range, and don't invalidate on clean */
>> +
>> + if (flags & MSM_GEM_SYNC_CACHE_CLEAN)
>> + sync_for_device(msm_obj);
>> +
>> + if (flags & MSM_GEM_SYNC_CACHE_INVALIDATE)
>> + sync_for_cpu(msm_obj);
>
> And make to these ones as well. They are complete abuses of the DMA
> API, and while we had to live with that for now to not cause regressions
> they absoutely must not be exposed in a userspace ABI like this.
>
How do you propose that cached non-coherent memory be implemented? It is
a useful feature for userspace.
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
next prev parent reply other threads:[~2020-10-03 9:23 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-01 0:27 [PATCH 0/3] drm/msm: support for host-cached BOs Jonathan Marek
2020-10-01 0:27 ` [PATCH 1/3] drm/msm: add MSM_BO_CACHED_COHERENT Jonathan Marek
2020-10-01 23:47 ` Jordan Crouse
2020-10-01 0:27 ` [PATCH 2/3] drm/msm: add DRM_MSM_GEM_SYNC_CACHE for non-coherent cache maintenance Jonathan Marek
2020-10-01 23:29 ` [Freedreno] " Jordan Crouse
[not found] ` <20201002075321.GA7547@infradead.org>
2020-10-02 12:46 ` Jonathan Marek [this message]
[not found] ` <20201005082914.GA31702@infradead.org>
2020-10-05 14:35 ` Jonathan Marek
[not found] ` <20201006072306.GA12834@infradead.org>
2020-10-06 13:19 ` Jonathan Marek
[not found] ` <20201007062519.GA23519@infradead.org>
2020-10-13 13:42 ` Robin Murphy
2020-10-13 16:11 ` Rob Clark
[not found] ` <20201015065532.GA15371@infradead.org>
2020-10-15 15:33 ` Daniel Vetter
2020-10-08 8:27 ` Joerg Roedel
2020-10-01 0:27 ` [PATCH 3/3] drm/msm: bump up the uapi version Jonathan Marek
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=b22fb797-67b0-a912-1d23-2b47c9a9e674@marek.ca \
--to=jonathan@marek.ca \
--cc=airlied@linux.ie \
--cc=dri-devel@lists.freedesktop.org \
--cc=freedreno@lists.freedesktop.org \
--cc=hch@infradead.org \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=sean@poorly.run \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).