From: Christoph Hellwig <hch@infradead.org>
To: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org,
dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
amd-gfx@lists.freedesktop.org,
Christian Koenig <christian.koenig@amd.com>,
Alex Deucher <alexander.deucher@amd.com>,
David Zhou <David1.Zhou@amd.com>, Huang Rui <ray.huang@amd.com>,
Junwei Zhang <Jerry.Zhang@amd.com>,
Michel Daenzer <michel.daenzer@amd.com>,
David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
Maxime Ripard <maxime.ripard@bootlin.com>,
Sean Paul <sean@poorly.run>,
Michael Ellerman <mpe@ellerman.id.au>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Will Deacon <will.deacon@arm.com>
Subject: Re: [RFC PATCH] drm: disable WC optimization for cache coherent devices on non-x86
Date: Mon, 21 Jan 2019 07:07:34 -0800 [thread overview]
Message-ID: <20190121150734.GA30582@infradead.org> (raw)
In-Reply-To: <20190121100617.2311-1-ard.biesheuvel@linaro.org>
> +#include <linux/dma-noncoherent.h>
This header is not for usage in device drivers, but purely for
dma-mapping implementations!
> +static inline bool drm_device_can_wc_memory(struct drm_device *ddev)
> {
> + if (IS_ENABLED(CONFIG_PPC))
> + return IS_ENABLED(CONFIG_NOT_COHERENT_CACHE);
> + else if (IS_ENABLED(CONFIG_MIPS))
> + return !IS_ENABLED(CONFIG_CPU_LOONGSON3);
> + else if (IS_ENABLED(CONFIG_X86))
> + return true;
> +
> + return !dev_is_dma_coherent(ddev->dev);
And even if something like this was valid to do, it would have to be
a core function with an arch hook, and not hidden in a random driver.
next prev parent reply other threads:[~2019-01-21 15:07 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-21 10:06 [RFC PATCH] drm: disable WC optimization for cache coherent devices on non-x86 Ard Biesheuvel
2019-01-21 10:11 ` Koenig, Christian
2019-01-21 15:07 ` Christoph Hellwig [this message]
2019-01-21 15:33 ` Ard Biesheuvel
2019-01-21 15:59 ` Christoph Hellwig
2019-01-21 16:14 ` Ard Biesheuvel
2019-01-21 16:22 ` Christoph Hellwig
2019-01-21 16:30 ` Ard Biesheuvel
2019-01-21 16:35 ` Christoph Hellwig
2019-01-21 16:50 ` Ard Biesheuvel
2019-01-21 17:55 ` Michel Dänzer
2019-01-21 17:59 ` Ard Biesheuvel
2019-01-21 18:04 ` Michel Dänzer
2019-01-21 18:20 ` Ard Biesheuvel
2019-01-21 18:23 ` Michel Dänzer
2019-01-21 18:28 ` Ard Biesheuvel
2019-01-21 19:04 ` Michel Dänzer
2019-01-21 19:18 ` Ard Biesheuvel
2019-01-22 8:38 ` Ard Biesheuvel
2019-01-22 20:56 ` Alex Deucher
2019-01-22 21:07 ` Ard Biesheuvel
2019-01-23 7:15 ` Christoph Hellwig
2019-01-23 9:08 ` Ard Biesheuvel
2019-01-23 16:44 ` Christoph Hellwig
2019-01-23 16:52 ` Ard Biesheuvel
2019-01-24 9:13 ` Christoph Hellwig
2019-01-24 9:25 ` Koenig, Christian
2019-01-24 9:28 ` Ard Biesheuvel
2019-01-24 9:45 ` Koenig, Christian
2019-01-24 9:59 ` Ard Biesheuvel
2019-01-24 11:23 ` Koenig, Christian
2019-01-24 11:26 ` Ard Biesheuvel
2019-01-24 11:37 ` Koenig, Christian
2019-01-24 11:45 ` Ard Biesheuvel
2019-01-24 13:54 ` Alex Deucher
2019-01-24 13:57 ` Ard Biesheuvel
2019-01-24 14:00 ` Alex Deucher
2019-01-24 16:04 ` Michel Dänzer
2019-01-24 9:31 ` Michel Dänzer
2019-01-24 9:37 ` Ard Biesheuvel
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=20190121150734.GA30582@infradead.org \
--to=hch@infradead.org \
--cc=David1.Zhou@amd.com \
--cc=Jerry.Zhang@amd.com \
--cc=airlied@linux.ie \
--cc=alexander.deucher@amd.com \
--cc=amd-gfx@lists.freedesktop.org \
--cc=ard.biesheuvel@linaro.org \
--cc=benh@kernel.crashing.org \
--cc=christian.koenig@amd.com \
--cc=daniel@ffwll.ch \
--cc=dri-devel@lists.freedesktop.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=maarten.lankhorst@linux.intel.com \
--cc=maxime.ripard@bootlin.com \
--cc=michel.daenzer@amd.com \
--cc=mpe@ellerman.id.au \
--cc=ray.huang@amd.com \
--cc=sean@poorly.run \
--cc=will.deacon@arm.com \
/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).