From: Christoph Hellwig <hch@infradead.org>
To: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: "Russell King - ARM Linux" <linux@armlinux.org.uk>,
"Christoph Hellwig" <hch@infradead.org>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
"amd-gfx list" <amd-gfx@lists.freedesktop.org>,
"moderated list:DMA BUFFER SHARING FRAMEWORK"
<linaro-mm-sig@lists.linaro.org>,
"Jerome Glisse" <jglisse@redhat.com>,
iommu@lists.linux-foundation.org,
dri-devel <dri-devel@lists.freedesktop.org>,
"Dan Williams" <dan.j.williams@intel.com>,
"Thierry Reding" <treding@nvidia.com>,
"Logan Gunthorpe" <logang@deltatee.com>,
"Christian König" <christian.koenig@amd.com>,
"Linux ARM" <linux-arm-kernel@lists.infradead.org>,
"open list:DMA BUFFER SHARING FRAMEWORK"
<linux-media@vger.kernel.org>
Subject: Re: [Linaro-mm-sig] noveau vs arm dma ops
Date: Thu, 26 Apr 2018 02:24:22 -0700 [thread overview]
Message-ID: <20180426092422.GA26825@infradead.org> (raw)
In-Reply-To: <CAKMK7uG9R6paoP4BmvqDVUP_4Db4Dz8MSXeLwUBMYaORa5-kVw@mail.gmail.com>
On Thu, Apr 26, 2018 at 11:20:44AM +0200, Daniel Vetter wrote:
> The above is already what we're implementing in i915, at least
> conceptually (it all boils down to clflush instructions because those
> both invalidate and flush).
The clwb instruction that just writes back dirty cache lines might
be very interesting for the x86 non-coherent dma case. A lot of
architectures use their equivalent to prepare to to device transfers.
> One architectural guarantee we're exploiting is that prefetched (and
> hence non-dirty) cachelines will never get written back, but dropped
> instead.
And to make this work you'll need exactly this guarantee.
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
To: Daniel Vetter <daniel.vetter-/w4YWyX8dFk@public.gmane.org>
Cc: "moderated list:DMA BUFFER SHARING FRAMEWORK"
<linaro-mm-sig-cunTk1MwBs8s++Sfvej+rw@public.gmane.org>,
"Russell King - ARM Linux"
<linux-I+IVW8TIWO2tmTQ+vhA3Yw@public.gmane.org>,
"amd-gfx list"
<amd-gfx-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org>,
"Linux Kernel Mailing List"
<linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
"Jerome Glisse" <jglisse-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org,
dri-devel
<dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org>,
"Dan Williams"
<dan.j.williams-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>,
"Thierry Reding"
<treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>,
"Logan Gunthorpe"
<logang-OTvnGxWRz7hWk0Htik3J/w@public.gmane.org>,
"Christian König" <christian.koenig-5C7GfCeVMHo@public.gmane.org>,
"Linux ARM"
<linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org>,
"open list:DMA BUFFER SHARING FRAMEWORK"
<linux-media-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: Re: [Linaro-mm-sig] noveau vs arm dma ops
Date: Thu, 26 Apr 2018 02:24:22 -0700 [thread overview]
Message-ID: <20180426092422.GA26825@infradead.org> (raw)
In-Reply-To: <CAKMK7uG9R6paoP4BmvqDVUP_4Db4Dz8MSXeLwUBMYaORa5-kVw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
On Thu, Apr 26, 2018 at 11:20:44AM +0200, Daniel Vetter wrote:
> The above is already what we're implementing in i915, at least
> conceptually (it all boils down to clflush instructions because those
> both invalidate and flush).
The clwb instruction that just writes back dirty cache lines might
be very interesting for the x86 non-coherent dma case. A lot of
architectures use their equivalent to prepare to to device transfers.
> One architectural guarantee we're exploiting is that prefetched (and
> hence non-dirty) cachelines will never get written back, but dropped
> instead.
And to make this work you'll need exactly this guarantee.
WARNING: multiple messages have this Message-ID (diff)
From: hch@infradead.org (Christoph Hellwig)
To: linux-arm-kernel@lists.infradead.org
Subject: [Linaro-mm-sig] noveau vs arm dma ops
Date: Thu, 26 Apr 2018 02:24:22 -0700 [thread overview]
Message-ID: <20180426092422.GA26825@infradead.org> (raw)
In-Reply-To: <CAKMK7uG9R6paoP4BmvqDVUP_4Db4Dz8MSXeLwUBMYaORa5-kVw@mail.gmail.com>
On Thu, Apr 26, 2018 at 11:20:44AM +0200, Daniel Vetter wrote:
> The above is already what we're implementing in i915, at least
> conceptually (it all boils down to clflush instructions because those
> both invalidate and flush).
The clwb instruction that just writes back dirty cache lines might
be very interesting for the x86 non-coherent dma case. A lot of
architectures use their equivalent to prepare to to device transfers.
> One architectural guarantee we're exploiting is that prefetched (and
> hence non-dirty) cachelines will never get written back, but dropped
> instead.
And to make this work you'll need exactly this guarantee.
next prev parent reply other threads:[~2018-04-26 9:24 UTC|newest]
Thread overview: 161+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-25 10:59 [PATCH 1/8] lib/scatterlist: add sg_set_dma_addr() helper Christian König
2018-03-25 10:59 ` Christian König
2018-03-25 10:59 ` [PATCH 2/8] PCI: Add pci_find_common_upstream_dev() Christian König
2018-03-25 10:59 ` Christian König
2018-03-28 12:38 ` Christoph Hellwig
2018-03-28 15:07 ` Christian König
2018-03-28 15:07 ` Christian König
2018-03-28 15:47 ` Logan Gunthorpe
2018-03-28 16:02 ` Christian König
2018-03-28 16:02 ` Christian König
2018-03-28 16:25 ` Logan Gunthorpe
2018-03-28 18:28 ` Christian König
2018-03-28 18:28 ` Christian König
2018-03-28 18:57 ` Logan Gunthorpe
2018-03-28 19:44 ` Christian König
2018-03-28 19:44 ` Christian König
2018-03-28 19:53 ` Logan Gunthorpe
2018-03-29 11:44 ` Christian König
2018-03-29 15:45 ` Logan Gunthorpe
2018-03-29 16:10 ` Christian König
2018-03-29 16:10 ` Christian König
2018-03-29 16:25 ` Logan Gunthorpe
2018-03-29 18:15 ` Christian König
2018-03-29 18:15 ` Christian König
2018-03-30 1:58 ` Jerome Glisse
2018-03-30 1:58 ` Jerome Glisse
2018-03-30 6:33 ` Christoph Hellwig
2018-03-30 6:33 ` Christoph Hellwig
2018-03-30 15:25 ` Jerome Glisse
2018-03-30 18:46 ` Logan Gunthorpe
2018-03-30 19:45 ` Jerome Glisse
2018-03-30 19:45 ` Jerome Glisse
2018-04-02 17:02 ` Logan Gunthorpe
2018-04-02 17:20 ` Jerome Glisse
2018-04-02 17:20 ` Jerome Glisse
2018-04-02 17:37 ` Logan Gunthorpe
2018-04-02 19:16 ` Jerome Glisse
2018-04-02 19:16 ` Jerome Glisse
2018-04-02 19:32 ` Logan Gunthorpe
2018-04-02 19:45 ` Jerome Glisse
2018-04-02 19:45 ` Jerome Glisse
[not found] ` <CADnq5_P-z=Noos_jaME9_CERri3C-m2hPPvx2bArr36O=1FnrA@mail.gmail.com>
2018-03-29 14:37 ` Alex Deucher
2018-03-29 14:37 ` Alex Deucher
2018-03-25 10:59 ` [PATCH 3/8] PCI: Add pci_peer_traffic_supported() Christian König
2018-03-25 10:59 ` Christian König
2018-03-25 10:59 ` [PATCH 4/8] dma-buf: add peer2peer flag Christian König
2018-03-25 10:59 ` Christian König
2018-03-29 6:57 ` Daniel Vetter
2018-03-29 6:57 ` Daniel Vetter
2018-03-29 11:34 ` Christian König
2018-03-29 11:34 ` Christian König
2018-04-03 9:09 ` Daniel Vetter
2018-04-03 9:09 ` Daniel Vetter
2018-04-03 17:06 ` Jerome Glisse
2018-04-03 17:06 ` Jerome Glisse
2018-04-03 18:08 ` Daniel Vetter
2018-04-03 18:08 ` Daniel Vetter
2018-04-16 12:39 ` Christoph Hellwig
2018-04-16 12:39 ` Christoph Hellwig
2018-04-16 13:38 ` Daniel Vetter
2018-04-16 13:38 ` Daniel Vetter
2018-04-19 8:16 ` Christoph Hellwig
2018-04-19 8:16 ` Christoph Hellwig
2018-04-20 7:13 ` Daniel Vetter
2018-04-20 7:13 ` Daniel Vetter
2018-04-20 8:58 ` Christian König
2018-04-20 8:58 ` Christian König
2018-04-20 10:17 ` Christoph Hellwig
2018-04-20 10:17 ` Christoph Hellwig
2018-04-20 10:44 ` Christian König
2018-04-20 10:44 ` Christian König
2018-04-20 12:46 ` Christoph Hellwig
2018-04-20 15:21 ` [Linaro-mm-sig] " Daniel Vetter
2018-04-24 18:48 ` Christoph Hellwig
2018-04-24 18:48 ` Christoph Hellwig
2018-04-24 19:32 ` Daniel Vetter
2018-04-24 19:32 ` Daniel Vetter
2018-04-25 5:48 ` Christoph Hellwig
2018-04-25 5:48 ` Christoph Hellwig
2018-04-25 6:10 ` Alex Deucher
2018-04-25 6:10 ` Alex Deucher
2018-04-25 6:13 ` Daniel Vetter
2018-04-25 6:13 ` Daniel Vetter
2018-04-25 6:23 ` Daniel Vetter
2018-04-25 6:23 ` Daniel Vetter
2018-04-25 6:43 ` Christoph Hellwig
2018-04-25 6:43 ` Christoph Hellwig
2018-04-25 7:02 ` Daniel Vetter
2018-04-25 7:02 ` Daniel Vetter
2018-04-25 7:09 ` Christoph Hellwig
2018-04-25 7:09 ` Christoph Hellwig
2018-04-25 7:30 ` Daniel Vetter
2018-04-25 7:30 ` Daniel Vetter
2018-04-25 7:56 ` Thierry Reding
2018-04-25 7:56 ` Thierry Reding
2018-04-25 8:55 ` Christoph Hellwig
2018-04-25 8:55 ` Christoph Hellwig
2018-04-25 7:43 ` Thierry Reding
2018-04-25 7:43 ` Thierry Reding
2018-04-25 7:41 ` Thierry Reding
2018-04-25 7:41 ` Thierry Reding
2018-04-25 8:54 ` noveau vs arm dma ops Christoph Hellwig
2018-04-25 8:54 ` Christoph Hellwig
2018-04-25 8:54 ` Christoph Hellwig
2018-04-25 9:25 ` Russell King - ARM Linux
2018-04-25 9:25 ` Russell King - ARM Linux
2018-04-25 10:04 ` Daniel Vetter
2018-04-25 10:04 ` Daniel Vetter
2018-04-25 10:04 ` Daniel Vetter
2018-04-25 15:33 ` Christoph Hellwig
2018-04-25 15:33 ` Christoph Hellwig
2018-04-25 15:33 ` Christoph Hellwig
2018-04-25 21:35 ` Daniel Vetter
2018-04-25 21:35 ` Daniel Vetter
2018-04-25 21:35 ` Daniel Vetter
2018-04-25 23:26 ` Russell King - ARM Linux
2018-04-25 23:26 ` Russell King - ARM Linux
2018-04-26 9:17 ` Daniel Vetter
2018-04-26 9:17 ` Daniel Vetter
2018-04-26 9:17 ` Daniel Vetter
2018-04-26 9:09 ` Christoph Hellwig
2018-04-26 9:09 ` Christoph Hellwig
2018-04-26 9:09 ` Christoph Hellwig
2018-04-26 9:45 ` Daniel Vetter
2018-04-26 9:45 ` Daniel Vetter
2018-04-26 9:45 ` Daniel Vetter
2018-04-26 11:12 ` Russell King - ARM Linux
2018-04-26 11:12 ` Russell King - ARM Linux
2018-04-25 22:54 ` Russell King - ARM Linux
2018-04-25 22:54 ` Russell King - ARM Linux
2018-04-26 9:13 ` Christoph Hellwig
2018-04-26 9:13 ` Christoph Hellwig
2018-04-26 9:13 ` Christoph Hellwig
2018-04-26 9:20 ` [Linaro-mm-sig] " Daniel Vetter
2018-04-26 9:20 ` Daniel Vetter
2018-04-26 9:20 ` Daniel Vetter
2018-04-26 9:24 ` Christoph Hellwig [this message]
2018-04-26 9:24 ` Christoph Hellwig
2018-04-26 9:24 ` Christoph Hellwig
2018-04-26 9:39 ` Daniel Vetter
2018-04-26 9:39 ` Daniel Vetter
2018-04-26 9:39 ` Daniel Vetter
2018-04-25 6:24 ` [Linaro-mm-sig] [PATCH 4/8] dma-buf: add peer2peer flag Alex Deucher
2018-04-25 6:24 ` Alex Deucher
2018-04-25 6:41 ` Christoph Hellwig
2018-04-25 6:41 ` Christoph Hellwig
2018-04-25 17:44 ` Alex Deucher
2018-04-25 17:44 ` Alex Deucher
2018-04-25 18:38 ` Dan Williams
2018-04-25 18:38 ` Dan Williams
2018-05-04 12:45 ` Lucas Stach
2018-03-25 10:59 ` [PATCH 5/8] drm/amdgpu: print DMA-buf status in debugfs Christian König
2018-03-25 10:59 ` Christian König
2018-03-25 10:59 ` [PATCH 6/8] drm/amdgpu: note that we can handle peer2peer DMA-buf Christian König
2018-03-25 10:59 ` Christian König
2018-03-25 10:59 ` [PATCH 7/8] drm/amdgpu: add amdgpu_gem_attach Christian König
2018-03-25 10:59 ` Christian König
2018-03-25 11:00 ` [PATCH 8/8] drm/amdgpu: add support for exporting VRAM using DMA-buf Christian König
2018-03-25 11:00 ` Christian König
2018-03-28 12:37 ` [PATCH 1/8] lib/scatterlist: add sg_set_dma_addr() helper Christoph Hellwig
2018-03-28 12:37 ` Christoph Hellwig
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