linux-kernel - Re: [PATCH 1/6] drm/v3d: Document cache flushing ABI.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 3 Dec 2018 17:22:54 +0000
From:   Dave Emett <david.emett@...adcom.com>
To:     Eric Anholt <eric@...olt.net>
Cc:     dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
        Thomas Spurden <thomas.spurden@...adcom.com>
Subject: Re: [PATCH 1/6] drm/v3d: Document cache flushing ABI.

> + * The caches (L1T, slice, and L2T) will be flushed before the job
> + * executes.  The TLB writes are guaranteed to have been flushed by

I would say before *each* job executes, as the caches are flushed
before both bin and render.
I wouldn't say "the caches" as not all of the V3D caches are flushed
before executing a control list. In particular, the VCD cache is not
cleared by the kernel driver (not even sure if there is a register
interface to do this); it is expected that the control list will do
this itself (using the CLEAR_VCD_CACHE instruction).
On 3.3 and earlier there is a separate L2C for instructions/uniforms
and a GCA. These do need to be flushed, and it looks like they are, so
they should be mentioned here.