From: Christoph Hellwig <hch@lst.de>
To: Nicolin Chen <nicoleotsuka@gmail.com>
Cc: hch@lst.de, robin.murphy@arm.com, m.szyprowski@samsung.com,
vdumpa@nvidia.com, linux@armlinux.org.uk,
catalin.marinas@arm.com, will.deacon@arm.com, chris@zankel.net,
jcmvbkbc@gmail.com, joro@8bytes.org, dwmw2@infradead.org,
tony@atomide.com, akpm@linux-foundation.org,
sfr@canb.auug.org.au, treding@nvidia.com, keescook@chromium.org,
iamjoonsoo.kim@lge.com, wsa+renesas@sang-engineering.com,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-xtensa@linux-xtensa.org,
iommu@lists.linux-foundation.org
Subject: Re: [RFC/RFT PATCH 1/2] dma-contiguous: Simplify dma_*_from_contiguous() function calls
Date: Tue, 30 Apr 2019 12:56:40 +0200 [thread overview]
Message-ID: <20190430105640.GA20021@lst.de> (raw)
In-Reply-To: <20190430015521.27734-2-nicoleotsuka@gmail.com>
So while I really, really like this cleanup it turns out it isn't
actually safe for arm :( arm remaps the CMA allocation in place
instead of using a new mapping, which can be done because they don't
share PMDs with the kernel.
So we'll probably need a __dma_alloc_from_contiguous version with
an additional bool fallback argument - everyone but arms uses
dma_alloc_from_contiguous as in your patch, just arm will get the
non-fallback one.
Sorry for not sorting this our earlier.
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Nicolin Chen <nicoleotsuka@gmail.com>
Cc: tony@atomide.com, catalin.marinas@arm.com, will.deacon@arm.com,
jcmvbkbc@gmail.com, hch@lst.de, sfr@canb.auug.org.au,
linux@armlinux.org.uk, treding@nvidia.com,
linux-xtensa@linux-xtensa.org, keescook@chromium.org,
akpm@linux-foundation.org, linux-arm-kernel@lists.infradead.org,
chris@zankel.net, wsa+renesas@sang-engineering.com,
robin.murphy@arm.com, linux-kernel@vger.kernel.org,
iommu@lists.linux-foundation.org, iamjoonsoo.kim@lge.com,
dwmw2@infradead.org
Subject: Re: [RFC/RFT PATCH 1/2] dma-contiguous: Simplify dma_*_from_contiguous() function calls
Date: Tue, 30 Apr 2019 12:56:40 +0200 [thread overview]
Message-ID: <20190430105640.GA20021@lst.de> (raw)
Message-ID: <20190430105640.2yqTdQD01DQTNiTwHAR9POsmLbDqzLWV_T0Tio1-wRo@z> (raw)
In-Reply-To: <20190430015521.27734-2-nicoleotsuka@gmail.com>
So while I really, really like this cleanup it turns out it isn't
actually safe for arm :( arm remaps the CMA allocation in place
instead of using a new mapping, which can be done because they don't
share PMDs with the kernel.
So we'll probably need a __dma_alloc_from_contiguous version with
an additional bool fallback argument - everyone but arms uses
dma_alloc_from_contiguous as in your patch, just arm will get the
non-fallback one.
Sorry for not sorting this our earlier.
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Nicolin Chen <nicoleotsuka@gmail.com>
Cc: tony@atomide.com, catalin.marinas@arm.com, will.deacon@arm.com,
jcmvbkbc@gmail.com, hch@lst.de, m.szyprowski@samsung.com,
sfr@canb.auug.org.au, joro@8bytes.org, linux@armlinux.org.uk,
treding@nvidia.com, linux-xtensa@linux-xtensa.org,
keescook@chromium.org, akpm@linux-foundation.org,
linux-arm-kernel@lists.infradead.org, chris@zankel.net,
wsa+renesas@sang-engineering.com, robin.murphy@arm.com,
linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org,
iamjoonsoo.kim@lge.com, dwmw2@infradead.org
Subject: Re: [RFC/RFT PATCH 1/2] dma-contiguous: Simplify dma_*_from_contiguous() function calls
Date: Tue, 30 Apr 2019 12:56:40 +0200 [thread overview]
Message-ID: <20190430105640.GA20021@lst.de> (raw)
In-Reply-To: <20190430015521.27734-2-nicoleotsuka@gmail.com>
So while I really, really like this cleanup it turns out it isn't
actually safe for arm :( arm remaps the CMA allocation in place
instead of using a new mapping, which can be done because they don't
share PMDs with the kernel.
So we'll probably need a __dma_alloc_from_contiguous version with
an additional bool fallback argument - everyone but arms uses
dma_alloc_from_contiguous as in your patch, just arm will get the
non-fallback one.
Sorry for not sorting this our earlier.
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-04-30 10:56 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-30 1:55 [RFC/RFT PATCH 0/2] Optimize dma_*_from_contiguous calls Nicolin Chen
2019-04-30 1:55 ` Nicolin Chen
2019-04-30 1:55 ` Nicolin Chen
2019-04-30 1:55 ` Nicolin Chen
2019-04-30 1:55 ` [RFC/RFT PATCH 1/2] dma-contiguous: Simplify dma_*_from_contiguous() function calls Nicolin Chen
2019-04-30 1:55 ` Nicolin Chen
2019-04-30 1:55 ` Nicolin Chen
2019-04-30 1:55 ` Nicolin Chen
2019-04-30 10:56 ` Christoph Hellwig [this message]
2019-04-30 10:56 ` Christoph Hellwig
2019-04-30 10:56 ` Christoph Hellwig
2019-04-30 12:37 ` Robin Murphy
2019-04-30 12:37 ` Robin Murphy
2019-04-30 12:37 ` Robin Murphy
2019-04-30 15:18 ` Christoph Hellwig
2019-04-30 15:18 ` Christoph Hellwig
2019-04-30 15:18 ` Christoph Hellwig
2019-04-30 19:46 ` Nicolin Chen
2019-04-30 19:46 ` Nicolin Chen
2019-04-30 19:46 ` Nicolin Chen
2019-04-30 12:52 ` Robin Murphy
2019-04-30 12:52 ` Robin Murphy
2019-04-30 12:52 ` Robin Murphy
2019-04-30 15:20 ` Christoph Hellwig
2019-04-30 15:20 ` Christoph Hellwig
2019-04-30 15:20 ` Christoph Hellwig
2019-04-30 1:55 ` [RFC/RFT PATCH 2/2] dma-contiguous: Use fallback alloc_pages for single pages Nicolin Chen
2019-04-30 1:55 ` Nicolin Chen
2019-04-30 1:55 ` Nicolin Chen
2019-04-30 1:55 ` Nicolin Chen
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