From: Christoph Hellwig <hch@lst.de>
To: Serge Semin <fancer.lancer@gmail.com>
Cc: "Christoph Hellwig" <hch@lst.de>,
"Robin Murphy" <robin.murphy@arm.com>,
"Serge Semin" <Sergey.Semin@baikalelectronics.ru>,
"Gustavo Pimentel" <gustavo.pimentel@synopsys.com>,
"Vinod Koul" <vkoul@kernel.org>,
"Jingoo Han" <jingoohan1@gmail.com>,
"Bjorn Helgaas" <bhelgaas@google.com>,
"Frank Li" <Frank.Li@nxp.com>,
"Manivannan Sadhasivam" <manivannan.sadhasivam@linaro.org>,
"Marek Szyprowski" <m.szyprowski@samsung.com>,
"Vladimir Murzin" <vladimir.murzin@arm.com>,
"Alexey Malahov" <Alexey.Malahov@baikalelectronics.ru>,
"Pavel Parkhomenko" <Pavel.Parkhomenko@baikalelectronics.ru>,
"Lorenzo Pieralisi" <lorenzo.pieralisi@arm.com>,
"Rob Herring" <robh@kernel.org>,
"Krzysztof Wilczyński" <kw@linux.com>,
linux-pci@vger.kernel.org, dmaengine@vger.kernel.org,
linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org
Subject: Re: [PATCH 03/25] dma-direct: take dma-ranges/offsets into account in resource mapping
Date: Wed, 20 Apr 2022 10:47:46 +0200 [thread overview]
Message-ID: <20220420084746.GA11606@lst.de> (raw)
In-Reply-To: <20220420083207.pd3hxbwezrm2ud6x@mobilestation>
I can't really comment on the dma-ranges exlcusion for P2P mappings,
as that predates my involvedment, however:
On Wed, Apr 20, 2022 at 11:32:07AM +0300, Serge Semin wrote:
> See, if I get to map a virtual memory address to be accessible by any
> PCIe peripheral device, then the dma_map_sg/dma_map_page/etc
> procedures will take the PCIe host controller dma-ranges into account.
> It will work as expected and the PCIe devices will see the memory what
> I specified. But if I get to pass the physical address of the same
> page or a physical address of some device of the DEVs space to the
> dma_map_resource(), then the PCIe dma-ranges won't be taken into
> account, and the result mapping will be incorrect. That's why the
> current dma_map_resource() implementation seems very confusing to me.
> As I see it phys_addr_t is the type of the Interconnect address space,
> meanwhile dma_addr_t describes the PCIe, DEVs address spaces.
>
> Based on what I said here and in my previous email could you explain
> what do I get wrong?
You simply must not use dma_map_resource for normal kernel memory.
So while the exclusion might be somewhat confusing, that confusion
really should not matter for any proper use of the API.
next prev parent reply other threads:[~2022-04-20 8:47 UTC|newest]
Thread overview: 79+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-24 1:48 [PATCH 00/25] dmaengine: dw-edma: Add RP/EP local DMA controllers support Serge Semin
2022-03-24 1:48 ` [PATCH 01/25] dmaengine: dw-edma: Drop dma_slave_config.direction field usage Serge Semin
2022-03-24 13:30 ` Manivannan Sadhasivam
2022-04-05 11:15 ` Serge Semin
2022-03-24 1:48 ` [PATCH 02/25] dmaengine: dw-edma: Fix eDMA Rd/Wr-channels and DMA-direction semantics Serge Semin
2022-03-24 1:48 ` [PATCH 03/25] dma-direct: take dma-ranges/offsets into account in resource mapping Serge Semin
2022-03-24 11:30 ` Robin Murphy
2022-04-17 22:44 ` Serge Semin
2022-04-20 7:12 ` Christoph Hellwig
2022-04-20 8:32 ` Serge Semin
2022-04-20 8:47 ` Christoph Hellwig [this message]
2022-04-20 8:55 ` Serge Semin
2022-04-21 14:45 ` Christoph Hellwig
2022-04-21 17:35 ` Serge Semin
2022-04-21 20:51 ` Robin Murphy
2022-04-24 21:46 ` Serge Semin
2022-03-24 1:48 ` [PATCH 04/25] dmaengine: Fix dma_slave_config.dst_addr description Serge Semin
2022-03-24 14:08 ` Manivannan Sadhasivam
2022-03-31 5:38 ` Vinod Koul
2022-03-31 7:13 ` Serge Semin
2022-03-31 10:50 ` Manivannan Sadhasivam
2022-03-24 1:48 ` [PATCH 05/25] dmaengine: dw-edma: Convert ll/dt phys-address to PCIe bus/DMA address Serge Semin
2022-03-24 16:23 ` Manivannan Sadhasivam
2022-03-24 1:48 ` [PATCH 06/25] dmaengine: dw-edma: Fix missing src/dst address of the interleaved xfers Serge Semin
2022-03-24 16:26 ` Manivannan Sadhasivam
2022-03-24 1:48 ` [PATCH 07/25] dmaengine: dw-edma: Don't permit non-inc " Serge Semin
2022-03-24 17:15 ` Manivannan Sadhasivam
2022-04-17 22:59 ` Serge Semin
2022-03-24 1:48 ` [PATCH 08/25] dmaengine: dw-edma: Fix invalid interleaved xfers semantics Serge Semin
2022-03-24 1:48 ` [PATCH 09/25] dmaengine: dw-edma: Add CPU to PCIe bus address translation Serge Semin
2022-03-24 17:25 ` Manivannan Sadhasivam
2022-03-24 1:48 ` [PATCH 10/25] dmaengine: dw-edma: Add PCIe bus address getter to the remote EP glue-driver Serge Semin
2022-03-24 17:41 ` Manivannan Sadhasivam
2022-03-24 1:48 ` [PATCH 11/25] dmaengine: dw-edma: Drop chancnt initialization Serge Semin
2022-03-24 17:42 ` Manivannan Sadhasivam
2022-03-24 1:48 ` [PATCH 12/25] dmaengine: dw-edma: Fix DebugFS reg entry type Serge Semin
2022-03-24 17:48 ` Manivannan Sadhasivam
2022-03-24 1:48 ` [PATCH 13/25] dmaengine: dw-edma: Stop checking debugfs_create_*() return value Serge Semin
2022-03-24 18:12 ` Manivannan Sadhasivam
2022-03-24 1:48 ` [PATCH 14/25] dmaengine: dw-edma: Add dw_edma prefix to the DebugFS nodes descriptor Serge Semin
2022-03-24 18:14 ` Manivannan Sadhasivam
2022-03-24 1:48 ` [PATCH 15/25] dmaengine: dw-edma: Convert DebugFS descs to being kz-allocated Serge Semin
2022-03-25 6:03 ` Manivannan Sadhasivam
2022-03-25 6:42 ` Manivannan Sadhasivam
2022-04-18 7:17 ` Serge Semin
2022-03-24 1:48 ` [PATCH 16/25] dmaengine: dw-edma: Simplify the DebugFS context CSRs init procedure Serge Semin
2022-03-25 6:27 ` Manivannan Sadhasivam
2022-03-25 6:31 ` Manivannan Sadhasivam
2022-04-18 8:23 ` Serge Semin
2022-03-24 1:48 ` [PATCH 17/25] dmaengine: dw-edma: Move eDMA data pointer to DebugFS node descriptor Serge Semin
2022-03-25 6:35 ` Manivannan Sadhasivam
2022-03-24 1:48 ` [PATCH 18/25] dmaengine: dw-edma: Join Write/Read channels into a single device Serge Semin
2022-03-25 7:34 ` Manivannan Sadhasivam
2022-03-24 1:48 ` [PATCH 19/25] dmaengine: dw-edma: Use DMA-engine device DebugFS subdirectory Serge Semin
2022-03-25 7:41 ` Manivannan Sadhasivam
2022-03-24 1:48 ` [PATCH 20/25] dmaengine: dw-edma: Use non-atomic io-64 methods Serge Semin
2022-03-25 8:28 ` Manivannan Sadhasivam
2022-04-18 11:37 ` Serge Semin
2022-03-24 1:48 ` [PATCH 21/25] dmaengine: dw-edma: Drop DT-region allocation Serge Semin
2022-03-25 8:33 ` Manivannan Sadhasivam
2022-03-24 1:48 ` [PATCH 22/25] dmaengine: dw-edma: Replace chip ID number with device name Serge Semin
2022-03-25 10:02 ` Manivannan Sadhasivam
2022-04-18 12:17 ` Serge Semin
2022-03-24 1:48 ` [PATCH 23/25] dmaengine: dw-edma: Bypass dma-ranges mapping for the local setup Serge Semin
2022-03-25 18:10 ` Manivannan Sadhasivam
2022-04-18 13:36 ` Serge Semin
2022-03-24 1:48 ` [PATCH 24/25] dmaengine: dw-edma: Skip cleanup procedure if no private data found Serge Semin
2022-03-25 18:15 ` Manivannan Sadhasivam
2022-04-18 13:48 ` Serge Semin
2022-04-23 14:45 ` Manivannan Sadhasivam
2022-03-24 1:48 ` [PATCH 25/25] PCI: dwc: Add DW eDMA engine support Serge Semin
2022-03-28 14:15 ` Manivannan Sadhasivam
2022-04-19 20:54 ` Serge Semin
2022-04-23 14:40 ` Manivannan Sadhasivam
2022-04-25 5:22 ` Manivannan Sadhasivam
2022-04-28 14:05 ` Serge Semin
2022-04-28 17:09 ` Manivannan Sadhasivam
2022-04-29 16:13 ` Serge Semin
2022-04-29 17:20 ` Manivannan Sadhasivam
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