From: Jason Gunthorpe <jgg@nvidia.com>
To: Leon Romanovsky <leon@kernel.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>,
iommu@lists.linux.dev, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org,
Russell King <linux@armlinux.org.uk>
Subject: Re: [PATCH v3 3/4] ARM: dma-mapping: Switch to physical address mapping callbacks
Date: Wed, 17 Sep 2025 16:08:46 -0300 [thread overview]
Message-ID: <20250917190846.GE1391379@nvidia.com> (raw)
In-Reply-To: <20250917184625.GA10800@unreal>
On Wed, Sep 17, 2025 at 09:46:25PM +0300, Leon Romanovsky wrote:
> Let's take as an example MIPS/jazzdma, should we call to vdma_alloc()
> in DMA_ATTR_MMIO case?
Yes, that is right, this is an iommu, so it has to be programmed.
> or directly return "phys" as it is done in other
> architectures?
Which?
> > vdpa can support ATTR_MMIO with the same iommu prot MMIO adjustment,
> > that would be a good additional patch.
>
> There is "bounce page" in VDPA, it sounds like swiotlb to me, which
> doesn't work with MMIO.
Oh OK, it eventually does call pfn_to_page().. This isn't the case I
thought it was, there is another one that just routes to iommu_map
Jason
next prev parent reply other threads:[~2025-09-17 19:08 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-16 7:32 [PATCH v3 0/4] Preparation to .map_page and .unmap_page removal Leon Romanovsky
2025-09-16 7:32 ` [PATCH v3 1/4] dma-mapping: prepare dma_map_ops to conversion to physical address Leon Romanovsky
2025-09-16 13:52 ` Jason Gunthorpe
2025-09-16 7:32 ` [PATCH v3 2/4] dma-mapping: convert dummy ops to physical address mapping Leon Romanovsky
2025-09-16 13:53 ` Jason Gunthorpe
2025-09-16 7:32 ` [PATCH v3 3/4] ARM: dma-mapping: Switch to physical address mapping callbacks Leon Romanovsky
2025-09-16 18:46 ` Jason Gunthorpe
2025-09-17 10:36 ` Leon Romanovsky
2025-09-17 11:32 ` Jason Gunthorpe
2025-09-17 13:41 ` Leon Romanovsky
2025-09-17 13:58 ` Jason Gunthorpe
2025-09-17 18:46 ` Leon Romanovsky
2025-09-17 19:08 ` Jason Gunthorpe [this message]
2025-09-17 19:46 ` Leon Romanovsky
2025-09-16 7:32 ` [PATCH v3 4/4] dma-mapping: remove unused mapping resource callbacks Leon Romanovsky
2025-09-16 12:19 ` Leon Romanovsky
2025-09-16 18:49 ` Jason Gunthorpe
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