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From: Christoph Hellwig <hch@lst.de>
To: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Alexey Kardashevskiy <aik@ozlabs.ru>,
	Christoph Hellwig <hch@lst.de>,
	iommu@lists.linux-foundation.org, linuxppc-dev@lists.ozlabs.org,
	Lu Baolu <baolu.lu@linux.intel.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Joerg Roedel <joro@8bytes.org>,
	Robin Murphy <robin.murphy@arm.com>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] dma-mapping: add a dma_ops_bypass flag to struct device
Date: Tue, 24 Mar 2020 08:55:14 +0100	[thread overview]
Message-ID: <20200324075514.GK23447@lst.de> (raw)
In-Reply-To: <87pnd22rke.fsf@linux.ibm.com>

On Tue, Mar 24, 2020 at 12:00:09PM +0530, Aneesh Kumar K.V wrote:
> dma_addr_t dma_direct_map_page(struct device *dev, struct page *page,
> 		unsigned long offset, size_t size, enum dma_data_direction dir,
> 		unsigned long attrs)
> {
> 	phys_addr_t phys = page_to_phys(page) + offset;
> 	dma_addr_t dma_addr = phys_to_dma(dev, phys);
> 
> 	if (unlikely(!dma_capable(dev, dma_addr, size, true))) {
> 			return iommu_map(dev, phys, size, dir, attrs);
> 
> 		return DMA_MAPPING_ERROR;

If powerpc hardware / firmware people really come up with crap that
stupid you'll have to handle it yourself and will always pay the
indirect call penality.

  reply	other threads:[~2020-03-24  7:55 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-20 14:16 generic DMA bypass flag v2 Christoph Hellwig
2020-03-20 14:16 ` [PATCH 1/2] dma-mapping: add a dma_ops_bypass flag to struct device Christoph Hellwig
2020-03-20 15:02   ` Greg Kroah-Hartman
2020-03-23  1:28   ` Alexey Kardashevskiy
2020-03-23  8:37     ` Christoph Hellwig
2020-03-23  8:50       ` Christoph Hellwig
2020-03-23 15:37         ` Aneesh Kumar K.V
2020-03-23 17:22           ` Christoph Hellwig
2020-03-24  3:05             ` Alexey Kardashevskiy
2020-03-24  6:30               ` Aneesh Kumar K.V
2020-03-24  7:55                 ` Christoph Hellwig [this message]
2020-03-24  7:54               ` Christoph Hellwig
2020-03-25  4:51                 ` Alexey Kardashevskiy
2020-03-25  8:37                   ` Christoph Hellwig
2020-03-26  1:26                     ` Alexey Kardashevskiy
2020-04-03  8:38                       ` Alexey Kardashevskiy
2020-04-06 11:50                         ` Christoph Hellwig
2020-04-06 13:25                           ` Alexey Kardashevskiy
2020-04-06 17:17                             ` Christoph Hellwig
2020-04-07 10:12                               ` Alexey Kardashevskiy
2020-04-14  6:21                                 ` Alexey Kardashevskiy
2020-04-14  6:30                                   ` Christoph Hellwig
2020-03-23  8:58       ` Alexey Kardashevskiy
2020-03-23 17:20         ` Christoph Hellwig
2020-03-24  3:37           ` Alexey Kardashevskiy
2020-03-24  4:55             ` Alexey Kardashevskiy
2020-03-24  7:52             ` Christoph Hellwig
2020-03-23 12:14   ` Robin Murphy
2020-03-23 12:55     ` Christoph Hellwig
2020-03-20 14:16 ` [PATCH 2/2] powerpc: use the generic dma_ops_bypass mode Christoph Hellwig
  -- strict thread matches above, loose matches on Subject: below --
2019-11-13 13:37 generic DMA bypass flag Christoph Hellwig
2019-11-13 13:37 ` [PATCH 1/2] dma-mapping: add a dma_ops_bypass flag to struct device Christoph Hellwig

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