2018-03-01 15:02 GMT+01:00 Mark Rutland <mark.rutland@xxxxxxx>: > On Thu, Mar 01, 2018 at 02:58:04PM +0100, Benjamin Gaignard wrote: >> On early boot stages STM32MP1 platform is able to dedicate some hardware blocks >> to a secure OS running in TrustZone. >> We need to avoid using those hardware blocks on non-secure context (i.e. kernel) >> because read/write accesses could generate illegale access exceptions. >> >> Extended TrustZone Protection driver make sure that device is disabled if >> non-secure world can't acces to it. >> >> version 2: >> - do not use notifier anymore >> - change status property value in device-tree if needed >> - use a list of phandle instead of hard coded array > > As mentioned on v1, I don't think this should be done in Linux at all. > > If you wish to handle this dynamically, please fixup the DT *before* > entering Linux. > > If you want a sane default in the dts file, put status = "disabled" on > all nodes which the secure world might take ownership of. That is the case, nodes are disabled by ealier boot stages before entering in Linux but, since mistakes and/or errors are always possible, fixup the DT to avoid illegal access exceptions make sense for me. Benjamin > > Thanks, > Mark. > >> NOTE: Those patches should be applied only on >> git://git.kernel.org/pub/scm/linux/kernel/git/atorgue/stm32.git stm32-next >> until this patch: https://lkml.org/lkml/2018/2/26/386 >> find it way to mainline because KBuild will complain about them. >> >> Benjamin Gaignard (2): >> dt-bindings: stm32: Add bindings for Extended TrustZone Protection >> ARM: mach-stm32: Add Extended TrustZone Protection driver >> >> .../bindings/arm/stm32/st,stm32mp1-etzpc.txt | 25 +++++ >> arch/arm/mach-stm32/Kconfig | 7 ++ >> arch/arm/mach-stm32/Makefile | 1 + >> arch/arm/mach-stm32/stm32-etzpc.c | 116 +++++++++++++++++++++ >> 4 files changed, 149 insertions(+) >> create mode 100644 Documentation/devicetree/bindings/arm/stm32/st,stm32mp1-etzpc.txt >> create mode 100644 arch/arm/mach-stm32/stm32-etzpc.c >> >> -- >> 2.15.0 >> -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
