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From: Christoph Hellwig <hch@lst.de>
To: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Christoph Hellwig <hch@lst.de>,
	dri-devel@lists.freedesktop.org,
	iommu@lists.linux-foundation.org, linaro-mm-sig@lists.linaro.org,
	linux-kernel@vger.kernel.org, Robin Murphy <robin.murphy@arm.com>,
	Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
	linux-arm-kernel@lists.infradead.org,
	David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Maxime Ripard <mripard@kernel.org>,
	Thomas Zimmermann <tzimmermann@suse.de>
Subject: Re: [PATCH v3 02/25] drm: core: fix common struct sg_table related issues
Date: Tue, 5 May 2020 13:09:50 +0200	[thread overview]
Message-ID: <20200505110950.GA19067@lst.de> (raw)
In-Reply-To: <5dd1cb55-accb-0dc6-4ca5-90c57cd19527@samsung.com>

On Tue, May 05, 2020 at 12:51:58PM +0200, Marek Szyprowski wrote:
> Hi Christoph,
> 
> On 05.05.2020 12:15, Christoph Hellwig wrote:
> >> -		for_each_sg_page(st->sgl, &sg_iter, st->nents, 0)
> >> +		for_each_sg_page(st->sgl, &sg_iter, st->orig_nents, 0)
> > Would it make sense to also add a for_each_sgtable_page helper that
> > hides the use of orig_nents?  To be used like:
> >
> > 		for_each_sgtable_page(st, &sg_iter, 0) {
> 
> We would need two helpers:
> 
> for_each_sgtable_cpu_page() and for_each_sgtable_dma_page().
> 
> I considered them, but then I found that there are already 
> for_each_sg_page(), for_each_sg_dma_page() and various special iterators 
> like sg_page_iter, sg_dma_page_iter and sg_mapping_iter. Too bad that 
> they are almost not used, at least in the DRM subsystem. I wonder if it 
> make sense to apply them or simply provide the two above mentioned 
> wrappers?

None of the helpers helps with passing the right parameters from the
sg_table.  So in doube we'd need wrappers for all of the above, or
none..

WARNING: multiple messages have this Message-ID
From: Christoph Hellwig <hch@lst.de>
To: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>,
	Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
	David Airlie <airlied@linux.ie>,
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
	linaro-mm-sig@lists.linaro.org, iommu@lists.linux-foundation.org,
	Maxime Ripard <mripard@kernel.org>,
	Daniel Vetter <daniel@ffwll.ch>,
	Robin Murphy <robin.murphy@arm.com>,
	Christoph Hellwig <hch@lst.de>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v3 02/25] drm: core: fix common struct sg_table related issues
Date: Tue, 5 May 2020 13:09:50 +0200	[thread overview]
Message-ID: <20200505110950.GA19067@lst.de> (raw)
In-Reply-To: <5dd1cb55-accb-0dc6-4ca5-90c57cd19527@samsung.com>

On Tue, May 05, 2020 at 12:51:58PM +0200, Marek Szyprowski wrote:
> Hi Christoph,
> 
> On 05.05.2020 12:15, Christoph Hellwig wrote:
> >> -		for_each_sg_page(st->sgl, &sg_iter, st->nents, 0)
> >> +		for_each_sg_page(st->sgl, &sg_iter, st->orig_nents, 0)
> > Would it make sense to also add a for_each_sgtable_page helper that
> > hides the use of orig_nents?  To be used like:
> >
> > 		for_each_sgtable_page(st, &sg_iter, 0) {
> 
> We would need two helpers:
> 
> for_each_sgtable_cpu_page() and for_each_sgtable_dma_page().
> 
> I considered them, but then I found that there are already 
> for_each_sg_page(), for_each_sg_dma_page() and various special iterators 
> like sg_page_iter, sg_dma_page_iter and sg_mapping_iter. Too bad that 
> they are almost not used, at least in the DRM subsystem. I wonder if it 
> make sense to apply them or simply provide the two above mentioned 
> wrappers?

None of the helpers helps with passing the right parameters from the
sg_table.  So in doube we'd need wrappers for all of the above, or
none..
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

WARNING: multiple messages have this Message-ID
From: Christoph Hellwig <hch@lst.de>
To: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>,
	Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
	David Airlie <airlied@linux.ie>,
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
	linaro-mm-sig@lists.linaro.org, iommu@lists.linux-foundation.org,
	Maxime Ripard <mripard@kernel.org>,
	Daniel Vetter <daniel@ffwll.ch>,
	Robin Murphy <robin.murphy@arm.com>,
	Christoph Hellwig <hch@lst.de>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v3 02/25] drm: core: fix common struct sg_table related issues
Date: Tue, 5 May 2020 13:09:50 +0200	[thread overview]
Message-ID: <20200505110950.GA19067@lst.de> (raw)
In-Reply-To: <5dd1cb55-accb-0dc6-4ca5-90c57cd19527@samsung.com>

On Tue, May 05, 2020 at 12:51:58PM +0200, Marek Szyprowski wrote:
> Hi Christoph,
> 
> On 05.05.2020 12:15, Christoph Hellwig wrote:
> >> -		for_each_sg_page(st->sgl, &sg_iter, st->nents, 0)
> >> +		for_each_sg_page(st->sgl, &sg_iter, st->orig_nents, 0)
> > Would it make sense to also add a for_each_sgtable_page helper that
> > hides the use of orig_nents?  To be used like:
> >
> > 		for_each_sgtable_page(st, &sg_iter, 0) {
> 
> We would need two helpers:
> 
> for_each_sgtable_cpu_page() and for_each_sgtable_dma_page().
> 
> I considered them, but then I found that there are already 
> for_each_sg_page(), for_each_sg_dma_page() and various special iterators 
> like sg_page_iter, sg_dma_page_iter and sg_mapping_iter. Too bad that 
> they are almost not used, at least in the DRM subsystem. I wonder if it 
> make sense to apply them or simply provide the two above mentioned 
> wrappers?

None of the helpers helps with passing the right parameters from the
sg_table.  So in doube we'd need wrappers for all of the above, or
none..

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

  reply	other threads:[~2020-05-05 11:09 UTC|newest]

Thread overview: 157+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20200505084308eucas1p1aa040c3ae325a6c7d92f956b1f5aad0d@eucas1p1.samsung.com>
2020-05-05  8:43 ` [PATCH v3 00/25] DRM: fix struct sg_table nents vs. orig_nents misuse Marek Szyprowski
2020-05-05  8:43   ` Marek Szyprowski
2020-05-05  8:43   ` Marek Szyprowski
2020-05-05  8:43   ` Marek Szyprowski
     [not found]   ` <CGME20200505084624eucas1p2a9a5c4d2aece2c1555a5480c19c2e050@eucas1p2.samsung.com>
2020-05-05  8:45     ` [PATCH v3 01/25] dma-mapping: add generic helpers for mapping sgtable objects Marek Szyprowski
2020-05-05  8:45       ` Marek Szyprowski
2020-05-05  8:45       ` Marek Szyprowski
2020-05-05  8:45       ` Marek Szyprowski
     [not found]       ` <CGME20200505084625eucas1p1a3c25fd171f360e0aab2f76700699454@eucas1p1.samsung.com>
2020-05-05  8:45         ` [PATCH v3 02/25] drm: core: fix common struct sg_table related issues Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05 10:15           ` Christoph Hellwig
2020-05-05 10:15             ` Christoph Hellwig
2020-05-05 10:15             ` Christoph Hellwig
2020-05-05 10:51             ` Marek Szyprowski
2020-05-05 10:51               ` Marek Szyprowski
2020-05-05 10:51               ` Marek Szyprowski
2020-05-05 10:51               ` Marek Szyprowski
2020-05-05 11:09               ` Christoph Hellwig [this message]
2020-05-05 11:09                 ` Christoph Hellwig
2020-05-05 11:09                 ` Christoph Hellwig
2020-05-08  7:12                 ` Marek Szyprowski
2020-05-08  7:12                   ` Marek Szyprowski
2020-05-08  7:12                   ` Marek Szyprowski
2020-05-08  7:12                   ` Marek Szyprowski
2020-05-08  7:16                   ` Christoph Hellwig
2020-05-08  7:16                     ` Christoph Hellwig
2020-05-08  7:16                     ` Christoph Hellwig
2020-05-12  9:05                     ` Marek Szyprowski
2020-05-12  9:05                       ` Marek Szyprowski
2020-05-12  9:05                       ` Marek Szyprowski
2020-05-12  9:05                       ` Marek Szyprowski
     [not found]       ` <CGME20200505084625eucas1p2b8ca16ff91ba9d6655f525ef85915d00@eucas1p2.samsung.com>
2020-05-05  8:45         ` [PATCH v3 03/25] drm: amdgpu: " Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
     [not found]       ` <CGME20200505084626eucas1p20753456727333c09718253ca5c32d98c@eucas1p2.samsung.com>
2020-05-05  8:45         ` [PATCH v3 04/25] drm: armada: " Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
     [not found]       ` <CGME20200505084626eucas1p20abe79e406f60ae92fec252072befc5a@eucas1p2.samsung.com>
2020-05-05  8:45         ` [PATCH v3 05/25] drm: etnaviv: " Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
     [not found]       ` <CGME20200505084627eucas1p119c77fbf28532627f27382efc51b0aaa@eucas1p1.samsung.com>
2020-05-05  8:45         ` [PATCH v3 06/25] drm: exynos: " Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
     [not found]       ` <CGME20200505084627eucas1p199eed52198b4409da1fa8e2256f5bb62@eucas1p1.samsung.com>
2020-05-05  8:45         ` [PATCH v3 07/25] drm: i915: " Marek Szyprowski
2020-05-05  8:45           ` [Intel-gfx] " Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
     [not found]       ` <CGME20200505084628eucas1p2c87aae2f471b716675559debbf680c46@eucas1p2.samsung.com>
2020-05-05  8:45         ` [PATCH v3 08/25] drm: lima: " Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
     [not found]       ` <CGME20200505084629eucas1p12e882329da88edd155ba9f9f952889a0@eucas1p1.samsung.com>
2020-05-05  8:45         ` [PATCH v3 09/25] drm: msm: " Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
     [not found]       ` <CGME20200505084629eucas1p23d2d6a53451e67e2b0a3544eb696008b@eucas1p2.samsung.com>
2020-05-05  8:45         ` [PATCH v3 10/25] drm: panfrost: " Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-11 15:51           ` Steven Price
2020-05-11 15:51             ` Steven Price
2020-05-11 15:51             ` Steven Price
2020-05-11 15:51             ` Steven Price
     [not found]       ` <CGME20200505084630eucas1p1c74cd5d287e1080b85d98edde405a577@eucas1p1.samsung.com>
2020-05-05  8:46         ` [PATCH v3 11/25] drm: radeon: " Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
     [not found]       ` <CGME20200505084630eucas1p2199401486591b681b84a4b24496295fb@eucas1p2.samsung.com>
2020-05-05  8:46         ` [PATCH v3 12/25] drm: rockchip: " Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
     [not found]       ` <CGME20200505084631eucas1p11121f9373a1d282f0262d1faa33f35fb@eucas1p1.samsung.com>
2020-05-05  8:46         ` [PATCH v3 13/25] drm: tegra: " Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
     [not found]       ` <CGME20200505084632eucas1p2e37c536205c057984c5f0355f6ffe1c2@eucas1p2.samsung.com>
2020-05-05  8:46         ` [PATCH v3 14/25] drm: virtio: " Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
     [not found]       ` <CGME20200505084632eucas1p231212e9cea88e755da8eaf1fb012d2c6@eucas1p2.samsung.com>
2020-05-05  8:46         ` [PATCH v3 15/25] drm: vmwgfx: " Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-12  0:19           ` [Linux-graphics-maintainer] " Roland Scheidegger
2020-05-12  0:19             ` Roland Scheidegger
2020-05-12  0:19             ` Roland Scheidegger
2020-05-12  0:19             ` Roland Scheidegger
     [not found]       ` <CGME20200505084633eucas1p26a6a3f44c64955aadec834bed027e522@eucas1p2.samsung.com>
2020-05-05  8:46         ` [PATCH v3 16/25] xen: gntdev: " Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
     [not found]       ` <CGME20200505084633eucas1p19798e1fb42c9430a93d668bc585e58da@eucas1p1.samsung.com>
2020-05-05  8:46         ` [PATCH v3 17/25] drm: host1x: " Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
     [not found]       ` <CGME20200505084634eucas1p1e0ea160dd77afbf6d2f7e6154ded40d0@eucas1p1.samsung.com>
2020-05-05  8:46         ` [PATCH v3 18/25] drm: rcar-du: " Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  9:24           ` Geert Uytterhoeven
2020-05-05  9:24             ` Geert Uytterhoeven
2020-05-05  9:24             ` Geert Uytterhoeven
2020-05-05  9:24             ` Geert Uytterhoeven
     [not found]       ` <CGME20200505084634eucas1p105456f28d9a7935190478546e566975f@eucas1p1.samsung.com>
2020-05-05  8:46         ` [PATCH v3 19/25] dmabuf: " Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
     [not found]       ` <CGME20200505084635eucas1p14800a1e2598364d168adecd57b94225c@eucas1p1.samsung.com>
2020-05-05  8:46         ` [PATCH v3 20/25] staging: ion: " Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
     [not found]       ` <CGME20200505084636eucas1p23a33d0b83ca284692713745d004f93ea@eucas1p2.samsung.com>
     [not found]         ` <20200505084614.30424-1-m.szyprowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
2020-05-05  8:46           ` [PATCH v3 21/25] staging: tegra-vde: " Marek Szyprowski
2020-05-05  8:46             ` Marek Szyprowski
2020-05-05  8:46             ` Marek Szyprowski
2020-05-05  8:46             ` Marek Szyprowski
2020-05-05  8:46             ` Marek Szyprowski
2020-05-05  8:46             ` Marek Szyprowski
     [not found]       ` <CGME20200505084637eucas1p20390fa3c010bde00e438cce1b48d209c@eucas1p2.samsung.com>
2020-05-05  8:46         ` [PATCH v3 22/25] misc: fastrpc: " Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
     [not found]       ` <CGME20200505084637eucas1p2c6d4b880698e8db97a8a9468692befe1@eucas1p2.samsung.com>
2020-05-05  8:46         ` [PATCH v3 23/25] rapidio: " Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
     [not found]       ` <CGME20200505084638eucas1p24f356b441a3589e9528d239c0b9ac666@eucas1p2.samsung.com>
2020-05-05  8:46         ` [PATCH v3 24/25] samples: vfio-mdev/mbochs: " Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
     [not found]       ` <CGME20200505084638eucas1p2d4add214063543248d81c0977e3f1823@eucas1p2.samsung.com>
2020-05-05  8:46         ` [PATCH v3 25/25] media: pci: fix common ALSA DMA-mapping related codes Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05 10:22       ` [PATCH v3 01/25] dma-mapping: add generic helpers for mapping sgtable objects Christoph Hellwig
2020-05-05 10:22         ` Christoph Hellwig
2020-05-05 10:22         ` Christoph Hellwig
2020-05-05 10:44         ` Marek Szyprowski
2020-05-05 10:44           ` Marek Szyprowski
2020-05-05 10:44           ` Marek Szyprowski
2020-05-05 10:44           ` Marek Szyprowski
2020-05-07  8:47       ` Hans Verkuil
2020-05-07  8:47         ` Hans Verkuil
2020-05-07  8:47         ` Hans Verkuil
2020-05-07  8:47         ` Hans Verkuil

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