All of lore.kernel.org
 help / color / mirror / Atom feed
From: Christoph Hellwig <hch@infradead.org>
To: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>,
	David Zhou <David1.Zhou@amd.com>,
	Maxime Ripard <maxime.ripard@bootlin.com>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	David Airlie <airlied@linux.ie>,
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Michel Daenzer <michel.daenzer@amd.com>,
	linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org,
	Junwei Zhang <Jerry.Zhang@amd.com>, Huang Rui <ray.huang@amd.com>,
	dri-devel@lists.freedesktop.org, Daniel Vetter <daniel@ffwll.ch>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Alex Deucher <alexander.deucher@amd.com>,
	Sean Paul <sean@poorly.run>,
	Christian Koenig <christian.koenig@amd.com>,
	linux-arm-kernel@lists.infradead.org
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.

WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@infradead.org>
To: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>,
	David Zhou <David1.Zhou@amd.com>,
	Maxime Ripard <maxime.ripard@bootlin.com>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	David Airlie <airlied@linux.ie>,
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Michel Daenzer <michel.daenzer@amd.com>,
	linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org,
	Junwei Zhang <Jerry.Zhang@amd.com>, Huang Rui <ray.huang@amd.com>,
	dri-devel@lists.freedesktop.org, Daniel Vetter <daniel@ffwll.ch>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Alex Deucher <alexander.deucher@amd.com>,
	Sean Paul <sean@poorly.run>,
	Christian Koenig <christian.koenig@amd.com>,
	linux-arm-kernel@lists.infradead.org
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.

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

WARNING: multiple messages have this Message-ID (diff)
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.

  parent reply	other threads:[~2019-01-21 15:07 UTC|newest]

Thread overview: 98+ 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 10:06 ` Ard Biesheuvel
2019-01-21 10:11 ` Koenig, Christian
2019-01-21 10:11   ` Koenig, Christian
2019-01-21 10:11   ` Koenig, Christian
2019-01-21 15:07 ` Christoph Hellwig [this message]
2019-01-21 15:07   ` Christoph Hellwig
2019-01-21 15:07   ` Christoph Hellwig
2019-01-21 15:33   ` Ard Biesheuvel
2019-01-21 15:33     ` Ard Biesheuvel
     [not found]     ` <CAKv+Gu-hR=uieOeg7QheA5yfAycUoi2vjZsDUvROKVjW4eUNqw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2019-01-21 15:59       ` Christoph Hellwig
2019-01-21 15:59         ` Christoph Hellwig
2019-01-21 15:59         ` Christoph Hellwig
2019-01-21 16:14         ` Ard Biesheuvel
2019-01-21 16:14           ` Ard Biesheuvel
2019-01-21 16:22           ` Christoph Hellwig
2019-01-21 16:22             ` Christoph Hellwig
2019-01-21 16:22             ` Christoph Hellwig
2019-01-21 16:30             ` Ard Biesheuvel
2019-01-21 16:30               ` Ard Biesheuvel
2019-01-21 16:35               ` Christoph Hellwig
2019-01-21 16:35                 ` Christoph Hellwig
2019-01-21 16:35                 ` Christoph Hellwig
2019-01-21 16:50                 ` Ard Biesheuvel
2019-01-21 16:50                   ` Ard Biesheuvel
     [not found]               ` <CAKv+Gu-5V-UjP_YzZBCEsa+o_G6BRSVw2ZimYGNEfRGf-aRPNg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2019-01-21 17:55                 ` Michel Dänzer
2019-01-21 17:55                   ` Michel Dänzer
2019-01-21 17:55                   ` Michel Dänzer
2019-01-21 17:59                   ` Ard Biesheuvel
2019-01-21 17:59                     ` Ard Biesheuvel
2019-01-21 17:59                     ` Ard Biesheuvel
2019-01-21 18:04                     ` Michel Dänzer
2019-01-21 18:04                       ` Michel Dänzer
2019-01-21 18:20                       ` Ard Biesheuvel
2019-01-21 18:20                         ` Ard Biesheuvel
2019-01-21 18:23                         ` Michel Dänzer
2019-01-21 18:23                           ` Michel Dänzer
2019-01-21 18:28                           ` Ard Biesheuvel
2019-01-21 18:28                             ` Ard Biesheuvel
     [not found]                             ` <CAKv+Gu99zHqcQtj6TiOXAr3Qa6WWhKem+DHVA_mAQ0-Bc0Vbqw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2019-01-21 19:04                               ` Michel Dänzer
2019-01-21 19:04                                 ` Michel Dänzer
2019-01-21 19:04                                 ` Michel Dänzer
2019-01-21 19:18                                 ` Ard Biesheuvel
2019-01-21 19:18                                   ` Ard Biesheuvel
2019-01-22  8:38                                 ` Ard Biesheuvel
2019-01-22  8:38                                   ` Ard Biesheuvel
     [not found]                                   ` <CAKv+Gu_VBd8agHASc5RS0eCgyXP64Lt_i4yPuBjKwGQ+5Lpd5Q-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2019-01-22 20:56                                     ` Alex Deucher
2019-01-22 20:56                                       ` Alex Deucher
2019-01-22 20:56                                       ` Alex Deucher
2019-01-22 21:07                                       ` Ard Biesheuvel
2019-01-22 21:07                                         ` Ard Biesheuvel
2019-01-23  7:15                                         ` Christoph Hellwig
2019-01-23  7:15                                           ` Christoph Hellwig
2019-01-23  9:08                                           ` Ard Biesheuvel
2019-01-23  9:08                                             ` Ard Biesheuvel
2019-01-23 16:44                                             ` Christoph Hellwig
2019-01-23 16:44                                               ` Christoph Hellwig
2019-01-23 16:44                                               ` Christoph Hellwig
2019-01-23 16:52                                               ` Ard Biesheuvel
2019-01-23 16:52                                                 ` Ard Biesheuvel
2019-01-23 16:52                                                 ` Ard Biesheuvel
2019-01-24  9:13                                                 ` Christoph Hellwig
2019-01-24  9:13                                                   ` Christoph Hellwig
     [not found]                                                   ` <20190124091316.GA22796-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
2019-01-24  9:25                                                     ` Koenig, Christian
2019-01-24  9:25                                                       ` Koenig, Christian
2019-01-24  9:25                                                       ` Koenig, Christian
2019-01-24  9:28                                                       ` Ard Biesheuvel
2019-01-24  9:28                                                         ` Ard Biesheuvel
     [not found]                                                         ` <CAKv+Gu_3LurSN-6w1WijPfpJpc+Pgu0YTnwTfMrXMF3-AKAnJA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2019-01-24  9:45                                                           ` Koenig, Christian
2019-01-24  9:45                                                             ` Koenig, Christian
2019-01-24  9:45                                                             ` Koenig, Christian
2019-01-24  9:59                                                             ` Ard Biesheuvel
2019-01-24  9:59                                                               ` Ard Biesheuvel
2019-01-24 11:23                                                               ` Koenig, Christian
2019-01-24 11:23                                                                 ` Koenig, Christian
2019-01-24 11:23                                                                 ` Koenig, Christian
2019-01-24 11:26                                                                 ` Ard Biesheuvel
2019-01-24 11:26                                                                   ` Ard Biesheuvel
     [not found]                                                                   ` <CAKv+Gu_2f0FaJ+Th7H48u4GrPX=MM9xw0fFjdwhfRrr1nhgEkA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2019-01-24 11:37                                                                     ` Koenig, Christian
2019-01-24 11:37                                                                       ` Koenig, Christian
2019-01-24 11:37                                                                       ` Koenig, Christian
2019-01-24 11:45                                                                       ` Ard Biesheuvel
2019-01-24 11:45                                                                         ` Ard Biesheuvel
2019-01-24 13:54                                                                         ` Alex Deucher
2019-01-24 13:54                                                                           ` Alex Deucher
2019-01-24 13:57                                                                           ` Ard Biesheuvel
2019-01-24 13:57                                                                             ` Ard Biesheuvel
     [not found]                                                                             ` <CAKv+Gu9Ch_+2wUirmPb1-dXGzWbF2XoH-b6DrtkBNEXpx5obPA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2019-01-24 14:00                                                                               ` Alex Deucher
2019-01-24 14:00                                                                                 ` Alex Deucher
2019-01-24 14:00                                                                                 ` Alex Deucher
2019-01-24 16:04                                                                         ` Michel Dänzer
2019-01-24 16:04                                                                           ` Michel Dänzer
2019-01-24 16:04                                                                           ` Michel Dänzer
     [not found]                                                 ` <CAKv+Gu-9vEKu8mG-o+-4M1ZcgZmTTJVfEdNS9R27AFX8P5sqyQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2019-01-24  9:31                                                   ` Michel Dänzer
2019-01-24  9:31                                                     ` Michel Dänzer
2019-01-24  9:31                                                     ` Michel Dänzer
2019-01-24  9:37                                                     ` Ard Biesheuvel
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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.