From: Hanjun Guo <guohanjun@huawei.com>
To: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: <linux-arm-kernel@lists.infradead.org>,
Will Deacon <will@kernel.org>,
Sudeep Holla <sudeep.holla@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Robin Murphy <robin.murphy@arm.com>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
<iommu@lists.linux-foundation.org>, <linux-acpi@vger.kernel.org>,
<devicetree@vger.kernel.org>, <linux-pci@vger.kernel.org>,
Rob Herring <robh+dt@kernel.org>, Joerg Roedel <joro@8bytes.org>,
Bjorn Helgaas <bhelgaas@google.com>,
Marc Zyngier <maz@kernel.org>,
Makarand Pawagi <makarand.pawagi@nxp.com>,
Diana Craciun <diana.craciun@oss.nxp.com>,
Laurentiu Tudor <laurentiu.tudor@nxp.com>
Subject: Re: [PATCH v2 01/12] ACPI/IORT: Make iort_match_node_callback walk the ACPI namespace for NC
Date: Tue, 30 Jun 2020 21:04:20 +0800 [thread overview]
Message-ID: <4817d766-0437-5356-a0b9-97b111d4cae2@huawei.com> (raw)
In-Reply-To: <20200630102454.GA17556@e121166-lin.cambridge.arm.com>
On 2020/6/30 18:24, Lorenzo Pieralisi wrote:
> On Tue, Jun 30, 2020 at 11:06:41AM +0800, Hanjun Guo wrote:
>
> [...]
>
>>> For devices that aren't described in the DSDT - IORT translations
>>> are determined by their ACPI parent device. Do you see/Have you
>>> found any issue with this approach ?
>>
>> The spec says "Describes the IO relationships between devices
>> represented in the ACPI namespace.", and in section 3.1.1.3 Named
>> component node, it says:
>
> PCI devices aren't necessarily described in the ACPI namespace and we
> still use IORT to describe them - through the RC node.
>
>> "Named component nodes are used to describe devices that are also
>> included in the Differentiated System Description Table (DSDT). See
>> [ACPI]."
>>
>> So from my understanding, the IORT spec for now, can only do ID
>> translations for devices in the DSDT.
>
> I think you can read this multiple ways but this patch does not
> change this concept. What changes, is applying parent's node IORT
> mapping to child nodes with no associated DSDT nodes, it is the
> same thing we do with PCI and the _DMA method - we could update
> the wording in the specs if that clarifies but I don't think this
> deliberately disregards the specifications.
I agree, but it's better to update the wording of the spec.
>
>>>> For a platform device, if I use its parent's full path name for
>>>> its named component entry, then it will match, but this will violate
>>>> the IORT spec.
>>>
>>> Can you elaborate on this please I don't get the point you
>>> are making.
>>
>> For example, device A is not described in DSDT so can't represent
>> as a NC node in IORT. Device B can be described in DSDT and it
>> is the parent of device A, so device B can be represented in IORT
>> with memory access properties and node flags with Substream width
>> and Stall supported info.
>>
>> When we trying to translate device A's ID, we reuse all the memory
>> access properties and node flags from its parent (device B), but
>> will it the same?
>
> I assume so why wouldn't it be ? Why would be describe them in
> a parent-child relationship if that's not how the system looks like
> in HW ?
The point I'm making is that I'm not sure all the memory access and
stall properties are the same for the parent and the device itself.
>
> Do you have a specific example in mind that we should be aware of ?
>
>> So the IORT spec don't support this, at least it's pretty vague
>> I think.
>
> I think that's a matter of wording, it can be updated if it needs be,
> reach out if you see any issue with the current approach please.
If the all the properties for parent and device itself are the same,
I have no strong opinion for this patch, but it's better to update
the wording of the spec as well.
Thanks
Hanjun
next prev parent reply other threads:[~2020-06-30 13:04 UTC|newest]
Thread overview: 82+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-21 12:59 [PATCH 00/12] ACPI/OF: Upgrade MSI/IOMMU ID mapping APIs Lorenzo Pieralisi
2020-05-21 12:59 ` [PATCH 01/12] ACPI/IORT: Make iort_match_node_callback walk the ACPI namespace for NC Lorenzo Pieralisi
2020-05-21 12:59 ` [PATCH 02/12] ACPI/IORT: Make iort_get_device_domain IRQ domain agnostic Lorenzo Pieralisi
2020-05-21 19:56 ` Bjorn Helgaas
2020-05-21 12:59 ` [PATCH 03/12] ACPI/IORT: Make iort_msi_map_rid() PCI agnostic Lorenzo Pieralisi
2020-05-21 13:00 ` [PATCH 04/12] ACPI/IORT: Remove useless PCI bus walk Lorenzo Pieralisi
2020-05-21 13:00 ` [PATCH 05/12] ACPI/IORT: Add an input ID to acpi_dma_configure() Lorenzo Pieralisi
2020-05-21 13:00 ` [PATCH 06/12] of/iommu: Make of_map_rid() PCI agnostic Lorenzo Pieralisi
2020-05-21 22:47 ` Rob Herring
2020-06-04 14:27 ` Lorenzo Pieralisi
2020-05-21 13:00 ` [PATCH 07/12] of/device: Add input id to of_dma_configure() Lorenzo Pieralisi
2020-05-21 23:02 ` Rob Herring
2020-06-04 14:49 ` Lorenzo Pieralisi
2020-05-21 13:00 ` [PATCH 08/12] of/irq: make of_msi_map_get_device_domain() bus agnostic Lorenzo Pieralisi
2020-05-21 19:57 ` Bjorn Helgaas
2020-05-21 13:00 ` [PATCH 09/12] dt-bindings: arm: fsl: Add msi-map device-tree binding for fsl-mc bus Lorenzo Pieralisi
2020-05-21 23:10 ` Rob Herring
2020-05-22 9:42 ` Robin Murphy
2020-05-22 9:57 ` Diana Craciun OSS
2020-05-22 14:08 ` Rob Herring
2020-05-22 14:34 ` Robin Murphy
2020-05-22 14:02 ` Rob Herring
2020-05-22 15:38 ` Laurentiu Tudor
2020-05-21 13:00 ` [PATCH 10/12] of/irq: Make of_msi_map_rid() PCI bus agnostic Lorenzo Pieralisi
2020-05-21 23:17 ` Rob Herring
2020-06-04 15:08 ` Lorenzo Pieralisi
2020-05-21 13:00 ` [PATCH 11/12] bus/fsl-mc: Refactor the MSI domain creation in the DPRC driver Lorenzo Pieralisi
2020-05-21 13:00 ` [PATCH 12/12] bus: fsl-mc: Add ACPI support for fsl-mc Lorenzo Pieralisi
2020-05-21 15:03 ` Laurentiu Tudor
2020-05-22 5:32 ` Makarand Pawagi
2020-05-22 9:53 ` Lorenzo Pieralisi
2020-06-19 8:20 ` [PATCH v2 00/12] ACPI/OF: Upgrade MSI/IOMMU ID mapping APIs Lorenzo Pieralisi
2020-06-19 8:20 ` [PATCH v2 01/12] ACPI/IORT: Make iort_match_node_callback walk the ACPI namespace for NC Lorenzo Pieralisi
2020-06-29 4:24 ` Hanjun Guo
2020-06-29 9:05 ` Lorenzo Pieralisi
2020-06-30 3:06 ` Hanjun Guo
2020-06-30 10:24 ` Lorenzo Pieralisi
2020-06-30 13:04 ` Hanjun Guo [this message]
2020-07-01 16:12 ` Robin Murphy
2020-07-02 8:22 ` Hanjun Guo
2020-07-09 9:21 ` Lorenzo Pieralisi
2020-07-09 12:48 ` Hanjun Guo
2020-08-18 0:49 ` Hanjun Guo
2020-06-19 8:20 ` [PATCH v2 02/12] ACPI/IORT: Make iort_get_device_domain IRQ domain agnostic Lorenzo Pieralisi
2020-06-19 8:20 ` [PATCH v2 03/12] ACPI/IORT: Make iort_msi_map_rid() PCI agnostic Lorenzo Pieralisi
2020-07-15 9:15 ` Lorenzo Pieralisi
2020-07-21 14:59 ` Bjorn Helgaas
2020-07-27 6:06 ` [EXT] " Makarand Pawagi
2020-06-19 8:20 ` [PATCH v2 04/12] ACPI/IORT: Remove useless PCI bus walk Lorenzo Pieralisi
2020-06-19 8:20 ` [PATCH v2 05/12] ACPI/IORT: Add an input ID to acpi_dma_configure() Lorenzo Pieralisi
2020-07-09 9:35 ` Lorenzo Pieralisi
2020-07-15 9:13 ` Lorenzo Pieralisi
2020-07-28 12:48 ` Lorenzo Pieralisi
2020-07-28 13:00 ` Rafael J. Wysocki
2020-06-19 8:20 ` [PATCH v2 06/12] of/iommu: Make of_map_rid() PCI agnostic Lorenzo Pieralisi
2020-06-22 13:26 ` Joerg Roedel
2020-07-13 23:57 ` Rob Herring
2020-06-19 8:20 ` [PATCH v2 07/12] of/device: Add input id to of_dma_configure() Lorenzo Pieralisi
2020-06-30 21:50 ` Rob Herring
2020-06-19 8:20 ` [PATCH v2 08/12] dt-bindings: arm: fsl: Add msi-map device-tree binding for fsl-mc bus Lorenzo Pieralisi
2020-06-30 21:55 ` Rob Herring
2020-06-19 8:20 ` [PATCH v2 09/12] of/irq: make of_msi_map_get_device_domain() bus agnostic Lorenzo Pieralisi
2020-06-30 21:50 ` Rob Herring
2020-06-19 8:20 ` [PATCH v2 10/12] of/irq: Make of_msi_map_rid() PCI " Lorenzo Pieralisi
2020-06-30 21:56 ` Rob Herring
2020-06-19 8:20 ` [PATCH v2 11/12] bus/fsl-mc: Refactor the MSI domain creation in the DPRC driver Lorenzo Pieralisi
2020-07-15 13:05 ` Marc Zyngier
2020-06-19 8:20 ` [PATCH v2 12/12] bus: fsl-mc: Add ACPI support for fsl-mc Lorenzo Pieralisi
2020-07-01 16:55 ` Laurentiu Tudor
2020-07-09 9:19 ` Lorenzo Pieralisi
2020-07-09 9:26 ` [EXT] " Makarand Pawagi
2020-07-09 10:14 ` Laurentiu Tudor
2020-07-09 10:37 ` Makarand Pawagi
2020-07-09 10:39 ` Laurentiu Tudor
2020-07-09 10:47 ` Diana Craciun OSS
2020-07-09 10:52 ` Makarand Pawagi
2020-07-15 10:06 ` Lorenzo Pieralisi
2020-07-16 3:23 ` Makarand Pawagi
2020-07-16 7:57 ` Marc Zyngier
2020-07-20 16:54 ` [PATCH v2 00/12] ACPI/OF: Upgrade MSI/IOMMU ID mapping APIs Lorenzo Pieralisi
2020-07-21 4:28 ` [EXT] " Makarand Pawagi
2020-07-28 17:01 ` Catalin Marinas
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