| Message ID | 20250226165314.34205-1-laurentiumihalcea111@gmail.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | imx8mp: add support for the IMX AIPSTZ bridge | expand |
Hi, On 25-02-26, Laurentiu Mihalcea wrote: > From: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com> > > The AIPSTZ bridge offers some security-related configurations which can > be used to restrict master access to certain peripherals on the bridge. > > Normally, this could be done from a secure environment such as ATF before > Linux boots but the configuration of AIPSTZ5 is lost each time the power > domain is powered off and then powered on. Because of this, it has to be > configured each time the power domain is turned on and before any master > tries to access the peripherals (e.g: AP, CM7, DSP, on i.MX8MP). My question still stands: Setting these bits requires very often that the core is running at EL3 (e.g. secure-monitor) which is not the case for Linux. Can you please provide more information how Linux can set these bits? Regards, Marco > The child-parent relationship between the bridge and its peripherals > should guarantee that the bridge is configured before the AP attempts > to access the IPs. > > Other masters should use the 'access-controllers' property to enforce > a dependency between their device and the bridge device (see the DSP, > for example). > > At the moment, we only want to apply a default, more relaxed > configuration, which is why the number of access controller cells > is 0. > > The initial version of the series can be found at [1]. The new version > should provide better management of the device dependencies. > > [1]: https://lore.kernel.org/linux-arm-kernel/20241119130726.2761726-1-daniel.baluta@nxp.com/ > > --- > Changes in v2: > * adress Frank Li's comments > * pick up some A-b/R-b's > * don't use "simple-bus" as the second compatible. As per Krzysztof's > comment, AIPSTZ is not a "simple-bus". > --- > > Laurentiu Mihalcea (5): > dt-bindings: bus: add documentation for the IMX AIPSTZ bridge > dt-bindings: dsp: fsl,dsp: document 'access-controllers' property > bus: add driver for IMX AIPSTZ bridge > arm64: dts: imx8mp: convert 'aips5' to 'aipstz5' > arm64: dts: imx8mp: make 'dsp' node depend on 'aips5' > > .../bindings/bus/fsl,imx8mp-aipstz.yaml | 86 +++++++++++++++++ > .../devicetree/bindings/dsp/fsl,dsp.yaml | 3 + > arch/arm64/boot/dts/freescale/imx8mp.dtsi | 9 +- > drivers/bus/Kconfig | 6 ++ > drivers/bus/Makefile | 1 + > drivers/bus/imx-aipstz.c | 92 +++++++++++++++++++ > 6 files changed, 194 insertions(+), 3 deletions(-) > create mode 100644 Documentation/devicetree/bindings/bus/fsl,imx8mp-aipstz.yaml > create mode 100644 drivers/bus/imx-aipstz.c > > -- > 2.34.1 > > >
From: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com> The AIPSTZ bridge offers some security-related configurations which can be used to restrict master access to certain peripherals on the bridge. Normally, this could be done from a secure environment such as ATF before Linux boots but the configuration of AIPSTZ5 is lost each time the power domain is powered off and then powered on. Because of this, it has to be configured each time the power domain is turned on and before any master tries to access the peripherals (e.g: AP, CM7, DSP, on i.MX8MP). The child-parent relationship between the bridge and its peripherals should guarantee that the bridge is configured before the AP attempts to access the IPs. Other masters should use the 'access-controllers' property to enforce a dependency between their device and the bridge device (see the DSP, for example). At the moment, we only want to apply a default, more relaxed configuration, which is why the number of access controller cells is 0. The initial version of the series can be found at [1]. The new version should provide better management of the device dependencies. [1]: https://lore.kernel.org/linux-arm-kernel/20241119130726.2761726-1-daniel.baluta@nxp.com/ --- Changes in v2: * adress Frank Li's comments * pick up some A-b/R-b's * don't use "simple-bus" as the second compatible. As per Krzysztof's comment, AIPSTZ is not a "simple-bus". --- Laurentiu Mihalcea (5): dt-bindings: bus: add documentation for the IMX AIPSTZ bridge dt-bindings: dsp: fsl,dsp: document 'access-controllers' property bus: add driver for IMX AIPSTZ bridge arm64: dts: imx8mp: convert 'aips5' to 'aipstz5' arm64: dts: imx8mp: make 'dsp' node depend on 'aips5' .../bindings/bus/fsl,imx8mp-aipstz.yaml | 86 +++++++++++++++++ .../devicetree/bindings/dsp/fsl,dsp.yaml | 3 + arch/arm64/boot/dts/freescale/imx8mp.dtsi | 9 +- drivers/bus/Kconfig | 6 ++ drivers/bus/Makefile | 1 + drivers/bus/imx-aipstz.c | 92 +++++++++++++++++++ 6 files changed, 194 insertions(+), 3 deletions(-) create mode 100644 Documentation/devicetree/bindings/bus/fsl,imx8mp-aipstz.yaml create mode 100644 drivers/bus/imx-aipstz.c