From: Jean-Philippe Brucker <jean-philippe@linaro.org>
To: will@kernel.org, lpieralisi@kernel.org, kw@linux.com,
robh@kernel.org, bhelgaas@google.com, krzk+dt@kernel.org,
conor+dt@kernel.org, liviu.dudau@arm.com, sudeep.holla@arm.com,
joro@8bytes.org
Cc: robin.murphy@arm.com, nicolinc@nvidia.com, ketanp@nvidia.com,
linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
iommu@lists.linux.dev, devicetree@vger.kernel.org,
Jean-Philippe Brucker <jean-philippe@linaro.org>
Subject: [PATCH 1/3] dt-bindings: PCI: generic: Add ats-supported property
Date: Mon, 29 Apr 2024 12:39:37 +0100 [thread overview]
Message-ID: <20240429113938.192706-3-jean-philippe@linaro.org> (raw)
In-Reply-To: <20240429113938.192706-2-jean-philippe@linaro.org>
Add a way for firmware to tell the OS that ATS is supported by the PCI
root complex. An endpoint with ATS enabled may send Translation Requests
and Translated Memory Requests, which look just like Normal Memory
Requests with a non-zero AT field. So a root controller that ignores the
AT field may simply forward the request to the IOMMU as a Normal Memory
Request, which could end badly. In any case, the endpoint will be
unusable.
The ats-supported property allows the OS to only enable ATS in endpoints
if the root controller can handle ATS requests. Only add the property to
pcie-host-ecam-generic for the moment. For non-generic root controllers,
availability of ATS can be inferred from the compatible string.
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
---
From a while ago: https://lore.kernel.org/all/20200219222454.GA16221@bogus/
---
Documentation/devicetree/bindings/pci/host-generic-pci.yaml | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/Documentation/devicetree/bindings/pci/host-generic-pci.yaml b/Documentation/devicetree/bindings/pci/host-generic-pci.yaml
index d25423aa71674..94d4a4914a483 100644
--- a/Documentation/devicetree/bindings/pci/host-generic-pci.yaml
+++ b/Documentation/devicetree/bindings/pci/host-generic-pci.yaml
@@ -110,6 +110,12 @@ properties:
iommu-map-mask: true
msi-parent: true
+ ats-supported:
+ description:
+ Indicates that a PCIe host controller supports ATS, and can handle Memory
+ Requests with Address Type (AT).
+ type: boolean
+
required:
- compatible
- reg
--
2.44.0
next prev parent reply other threads:[~2024-04-29 11:43 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-29 11:39 [PATCH 0/3] Enable PCIe ATS for devicetree boot Jean-Philippe Brucker
2024-04-29 11:39 ` Jean-Philippe Brucker [this message]
2024-04-30 10:22 ` [PATCH 1/3] dt-bindings: PCI: generic: Add ats-supported property Liviu Dudau
2024-04-29 11:39 ` [PATCH 2/3] iommu/of: Support ats-supported device-tree property Jean-Philippe Brucker
2024-04-29 15:00 ` Jason Gunthorpe
2024-04-30 10:23 ` Liviu Dudau
2024-04-30 13:57 ` Robin Murphy
2024-05-02 4:55 ` Nicolin Chen
2024-04-29 11:39 ` [PATCH 3/3] arm64: dts: fvp: Enable PCIe ATS for Base RevC FVP Jean-Philippe Brucker
2024-05-16 10:44 ` Sudeep Holla
2024-05-15 18:28 ` [PATCH 0/3] Enable PCIe ATS for devicetree boot Vidya Sagar
2024-05-15 18:52 ` Bjorn Helgaas
2024-05-16 7:35 ` Jean-Philippe Brucker
2024-05-16 10:41 ` Sudeep Holla
2024-05-16 11:42 ` Jean-Philippe Brucker
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20240429113938.192706-3-jean-philippe@linaro.org \
--to=jean-philippe@linaro.org \
--cc=bhelgaas@google.com \
--cc=conor+dt@kernel.org \
--cc=devicetree@vger.kernel.org \
--cc=iommu@lists.linux.dev \
--cc=joro@8bytes.org \
--cc=ketanp@nvidia.com \
--cc=krzk+dt@kernel.org \
--cc=kw@linux.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-pci@vger.kernel.org \
--cc=liviu.dudau@arm.com \
--cc=lpieralisi@kernel.org \
--cc=nicolinc@nvidia.com \
--cc=robh@kernel.org \
--cc=robin.murphy@arm.com \
--cc=sudeep.holla@arm.com \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).