From: Christoph Hellwig <hch@lst.de>
To: "Lendacky, Thomas" <Thomas.Lendacky@amd.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Halil Pasic <pasic@linux.ibm.com>,
"iommu@lists.linux-foundation.org"
<iommu@lists.linux-foundation.org>,
Christoph Hellwig <hch@lst.de>,
Lucas Stach <l.stach@pengutronix.de>
Subject: Re: Regression due to d98849aff879 (dma-direct: handle DMA_ATTR_NO_KERNEL_MAPPING in common code)
Date: Tue, 6 Aug 2019 17:46:02 +0200 [thread overview]
Message-ID: <20190806154602.GB25050@lst.de> (raw)
In-Reply-To: <78833204-cd30-1a4b-54e3-1580018c6d57@amd.com>
On Tue, Aug 06, 2019 at 02:18:49PM +0000, Lendacky, Thomas wrote:
> I think you need to keep everything inside the original if statement since
> the caller is expecting a page pointer to be returned in this case and not
> the page_address() which is returned when the DMA_ATTR_NO_KERNEL_MAPPING
> is not present.
DMA_ATTR_NO_KERNEL_MAPPING is defined to return an opaque cookie,
which just happens to be a page pointer. So if we fix up the free side
as pointed out by Lucas we should be fine.
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WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: "Lendacky, Thomas" <Thomas.Lendacky@amd.com>
Cc: Lucas Stach <l.stach@pengutronix.de>,
Christoph Hellwig <hch@lst.de>,
"iommu@lists.linux-foundation.org"
<iommu@lists.linux-foundation.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Thiago Jung Bauermann <bauerman@linux.ibm.com>,
Halil Pasic <pasic@linux.ibm.com>
Subject: Re: Regression due to d98849aff879 (dma-direct: handle DMA_ATTR_NO_KERNEL_MAPPING in common code)
Date: Tue, 6 Aug 2019 17:46:02 +0200 [thread overview]
Message-ID: <20190806154602.GB25050@lst.de> (raw)
In-Reply-To: <78833204-cd30-1a4b-54e3-1580018c6d57@amd.com>
On Tue, Aug 06, 2019 at 02:18:49PM +0000, Lendacky, Thomas wrote:
> I think you need to keep everything inside the original if statement since
> the caller is expecting a page pointer to be returned in this case and not
> the page_address() which is returned when the DMA_ATTR_NO_KERNEL_MAPPING
> is not present.
DMA_ATTR_NO_KERNEL_MAPPING is defined to return an opaque cookie,
which just happens to be a page pointer. So if we fix up the free side
as pointed out by Lucas we should be fine.
next prev parent reply other threads:[~2019-08-06 15:46 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-06 9:13 Regression due to d98849aff879 (dma-direct: handle DMA_ATTR_NO_KERNEL_MAPPING in common code) Lucas Stach
2019-08-06 9:13 ` Lucas Stach
2019-08-06 11:33 ` Christoph Hellwig
2019-08-06 11:33 ` Christoph Hellwig
2019-08-06 12:20 ` Lucas Stach
2019-08-06 12:20 ` Lucas Stach
2019-08-06 13:38 ` Lendacky, Thomas
2019-08-06 13:38 ` Lendacky, Thomas
2019-08-06 14:04 ` Christoph Hellwig
2019-08-06 14:04 ` Christoph Hellwig
2019-08-06 14:06 ` Lucas Stach
2019-08-06 14:06 ` Lucas Stach
2019-08-06 14:18 ` Lendacky, Thomas
2019-08-06 14:18 ` Lendacky, Thomas
2019-08-06 15:46 ` Christoph Hellwig [this message]
2019-08-06 15:46 ` Christoph Hellwig
2019-08-06 15:59 ` Lendacky, Thomas
2019-08-06 15:59 ` Lendacky, Thomas
2019-08-06 16:07 ` Christoph Hellwig
2019-08-06 16:07 ` Christoph Hellwig
2019-08-06 15:44 ` Christoph Hellwig
2019-08-06 15:44 ` Christoph Hellwig
2019-08-07 15:24 ` Lucas Stach
2019-08-07 15:24 ` Lucas Stach
2019-08-08 7:48 ` Christoph Hellwig
2019-08-08 7:48 ` Christoph Hellwig
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