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ce4c430172
For the i.MX95, the configuration of a LUT is necessary to convert PCIe
Requester IDs (RIDs) to StreamIDs, which are used by both IOMMU and ITS.
This involves checking msi-map and iommu-map device tree properties to
ensure consistent mapping of Requester IDs to the same StreamIDs.
Subsequently, LUT-related registers are configured. If a msi-map isn't
detected, the platform relies on DWC built-in controller for MSIs that
do not need StreamIDs.
Implement PCI bus callback function to handle enable_device() and
disable_device() operations, setting up the LUT whenever a new PCI
device is enabled.
Known limitations:
- If iommu-map exists in the device tree but the IOMMU controller is
disabled, StreamIDs are programmed into the LUT. However, if a RID
is out of range of the iommu-map, enabling the PCI device would
result in a failure, although the PCI device can work without the
IOMMU.
- If msi-map exists in the device tree but the MSI controller is
disabled, MSIs will not work. The DWC driver skips initializing the
built-in MSI controller, falling back to legacy PCI INTx only.
Link: https://lore.kernel.org/r/20250114-imx95_lut-v9-2-39f58dbed03a@nxp.com
Signed-off-by: Frank Li <Frank.Li@nxp.com>
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
[bhelgaas: fix uninitialized "sid" in imx_pcie_enable_device()]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Richard Zhu <hongxing.zhu@nxp.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
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In order to build the documentation, use ``make htmldocs`` or
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There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.