| Message ID | 1377564633-31638-1-git-send-email-robherring2@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Aug 27, 2013 at 01:50:33AM +0100, Rob Herring wrote: > From: Rob Herring <rob.herring@calxeda.com> Hi Rob, Sorry for the delay on reviewing this. > > The PSCI spec from ARM has been updated to 0.2 version. Update the > binding document to reflect the spec changes. For the binding, the > major changes are the addition of psci_version, affinity_info, > migrate_info_type, migrate_info_up_cpu, system_reset and system_off > functions. The recommended function ID numbering has also changed. > > This update also defines 32 and 64 bit calling conventions. The calling > convention is defined on a per function ID basis. > > Signed-off-by: Rob Herring <rob.herring@calxeda.com> > Cc: Dave Martin <Dave.Martin@arm.com> > Cc: Mark Rutland <mark.rutland@arm.com> > Cc: Ian Campbell <Ian.Campbell@citrix.com> > Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> > Cc: Marc Zyngier <Marc.Zyngier@arm.com> > Cc: Christoffer Dall <christoffer.dall@linaro.org>, > Cc: Charles Garcia-Tobin <Charles.Garcia-Tobin@arm.com> > Cc: Matt Sealey <neko@bakuhatsu.net> > Cc: devicetree@vger.kernel.org > --- > v3: This version implements Mark's suggested binding with -32 and -64 suffixes. > > Documentation/devicetree/bindings/arm/psci.txt | 62 +++++++++++++++++++------- > 1 file changed, 46 insertions(+), 16 deletions(-) > > diff --git a/Documentation/devicetree/bindings/arm/psci.txt b/Documentation/devicetree/bindings/arm/psci.txt > index 433afe9..209bb04 100644 > --- a/Documentation/devicetree/bindings/arm/psci.txt > +++ b/Documentation/devicetree/bindings/arm/psci.txt > @@ -1,16 +1,17 @@ > * Power State Coordination Interface (PSCI) > > Firmware implementing the PSCI functions described in ARM document number > -ARM DEN 0022A ("Power State Coordination Interface System Software on ARM > +ARM DEN 0022B ("Power State Coordination Interface System Software on ARM > processors") can be used by Linux to initiate various CPU-centric power > operations. > > -Issue A of the specification describes functions for CPU suspend, hotplug > -and migration of secure software. > +Issue B of the specification describes functions for CPU suspend, hotplug, > +migration of secure software, and system level reset and powerdown. > > Functions are invoked by trapping to the privilege level of the PSCI > firmware (specified as part of the binding below) and passing arguments > -in a manner similar to that specified by AAPCS: > +as defined in ARM document "SMC Calling Convention" (ARM DEN 0028) in a manner > +similar to that specified by AAPCS: > > r0 => 32-bit Function ID / return value > {r1 - r3} => Parameters > @@ -21,10 +22,10 @@ to #0. > > Main node required properties: > > - - compatible : Must be "arm,psci" > + - compatible : Must contain "arm,psci-0.2" or "arm,psci" > > - - method : The method of calling the PSCI firmware. Permitted > - values are: > + - method : The method defines the calling convention for the PSCI > + firmware. Permitted values are: > > "smc" : SMC #0, with the register assignments specified > in this binding. > @@ -32,24 +33,53 @@ Main node required properties: > "hvc" : HVC #0, with the register assignments specified > in this binding. > > + - psci_version : Function ID for PSCI_VERSION operation. Required for > + "arm,psci-0.2" compatible version or later. > + While this seems sensible, I'm not sure that this needs to be mandatory. > Main node optional properties: > > - - cpu_suspend : Function ID for CPU_SUSPEND operation > + - cpu_suspend[-<32|64] : Function ID for CPU_SUSPEND operation > + > + - cpu_off : Function ID for CPU_OFF operation > + > + - cpu_on[-<32|64] : Function ID for CPU_ON operation > + > + - affinity_info[-<32|64] : Function ID for AFFINITY_INFO operation > > - - cpu_off : Function ID for CPU_OFF operation > + - migrate[-<32|64] : Function ID for MIGRATE operation > > - - cpu_on : Function ID for CPU_ON operation > + - migrate_info_type : Function ID for MIGRATE_INFO_TYPE operation > > - - migrate : Function ID for MIGRATE operation > + - migrate_info_up_cpu[-<32|64] : Function ID for MIGRATE_INFO_UP_CPU operation > > + - system_reset : Function ID for SYSTEM_RESET operation > + > + - system_off : Function ID for SYSTEM_OFF operation > + > +Some function IDs support 32-bit and 64-bit calling conventions. If no size is > +specified, then the 32-bit calling convention is used. Therefore, all function > +IDs for 64-bit calling convention are required to have "-64" suffix. Use of the > +"-32" suffix is recommended, but not required for backwards compatibility. I don't think we can say that non suffixed IDs mean use the 32-bit calling convention -- the arm64 PSCI code uses 64-bit parameters at the moment for non-suffixed IDs. I think if we say that callers should use their native register width calling convention for non-suffixed IDs, it's compatible with all PSCI implementations using DT in the wild currently. Implementations on v7 don't have AArch64 state, so can't ever use the 64-bit convention, and existing 64-bit implementations like KVM has are implemented at EL2, so the guest is stuck at a particular register width. Given that, how about the below? Some functions have have separate IDs for 32-bit and 64-bit calling conventions. These separate function IDs are described with function names with "-64" and "-32" suffixes (e.g. cpu_on-64). Where a function name does not have a suffix, the ID may be used with either calling convention depending on the CPU state -- AArch32 callers should use the 32-bit calling convention, and AArch64 callers should use the 64-bit calling convention. Thanks, Mark. > > Example: > > psci { > - compatible = "arm,psci"; > + compatible = "arm,psci-0.2"; > method = "smc"; > - cpu_suspend = <0x95c10000>; > - cpu_off = <0x95c10001>; > - cpu_on = <0x95c10002>; > - migrate = <0x95c10003>; > + psci_version = <0x84000000>; > + cpu_suspend-32 = <0x84000001>; > + cpu_suspend-64 = <0xc4000001>; > + cpu_off = <0x84000002>; > + cpu_on-32 = <0x84000003>; > + cpu_on-64 = <0xc4000003>; > + affinity_info-32 = <0x84000004>; > + affinity_info-64 = <0xc4000004>; > + migrate-32 = <0x84000005>; > + migrate-64 = <0xc4000005>; > + migrate_info_type = <0x84000006>; > + migrate_info_up_cpu-32 = <0x84000007>; > + migrate_info_up_cpu-64 = <0xc4000007>; > + system_off = <0x84000008>; > + system_reset = <0x84000009>; > }; > + > -- > 1.8.1.2 > >
On Tue, Sep 3, 2013 at 4:52 AM, Mark Rutland <mark.rutland@arm.com> wrote: > On Tue, Aug 27, 2013 at 01:50:33AM +0100, Rob Herring wrote: >> From: Rob Herring <rob.herring@calxeda.com> > > Hi Rob, > > Sorry for the delay on reviewing this. > >> >> The PSCI spec from ARM has been updated to 0.2 version. Update the >> binding document to reflect the spec changes. For the binding, the >> major changes are the addition of psci_version, affinity_info, >> migrate_info_type, migrate_info_up_cpu, system_reset and system_off >> functions. The recommended function ID numbering has also changed. >> >> This update also defines 32 and 64 bit calling conventions. The calling >> convention is defined on a per function ID basis. >> >> Signed-off-by: Rob Herring <rob.herring@calxeda.com> >> Cc: Dave Martin <Dave.Martin@arm.com> >> Cc: Mark Rutland <mark.rutland@arm.com> >> Cc: Ian Campbell <Ian.Campbell@citrix.com> >> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> >> Cc: Marc Zyngier <Marc.Zyngier@arm.com> >> Cc: Christoffer Dall <christoffer.dall@linaro.org>, >> Cc: Charles Garcia-Tobin <Charles.Garcia-Tobin@arm.com> >> Cc: Matt Sealey <neko@bakuhatsu.net> >> Cc: devicetree@vger.kernel.org >> --- >> v3: This version implements Mark's suggested binding with -32 and -64 suffixes. >> >> Documentation/devicetree/bindings/arm/psci.txt | 62 +++++++++++++++++++------- >> 1 file changed, 46 insertions(+), 16 deletions(-) >> >> diff --git a/Documentation/devicetree/bindings/arm/psci.txt b/Documentation/devicetree/bindings/arm/psci.txt >> index 433afe9..209bb04 100644 >> --- a/Documentation/devicetree/bindings/arm/psci.txt >> +++ b/Documentation/devicetree/bindings/arm/psci.txt >> @@ -1,16 +1,17 @@ >> * Power State Coordination Interface (PSCI) >> >> Firmware implementing the PSCI functions described in ARM document number >> -ARM DEN 0022A ("Power State Coordination Interface System Software on ARM >> +ARM DEN 0022B ("Power State Coordination Interface System Software on ARM >> processors") can be used by Linux to initiate various CPU-centric power >> operations. >> >> -Issue A of the specification describes functions for CPU suspend, hotplug >> -and migration of secure software. >> +Issue B of the specification describes functions for CPU suspend, hotplug, >> +migration of secure software, and system level reset and powerdown. >> >> Functions are invoked by trapping to the privilege level of the PSCI >> firmware (specified as part of the binding below) and passing arguments >> -in a manner similar to that specified by AAPCS: >> +as defined in ARM document "SMC Calling Convention" (ARM DEN 0028) in a manner >> +similar to that specified by AAPCS: >> >> r0 => 32-bit Function ID / return value >> {r1 - r3} => Parameters >> @@ -21,10 +22,10 @@ to #0. >> >> Main node required properties: >> >> - - compatible : Must be "arm,psci" >> + - compatible : Must contain "arm,psci-0.2" or "arm,psci" >> >> - - method : The method of calling the PSCI firmware. Permitted >> - values are: >> + - method : The method defines the calling convention for the PSCI >> + firmware. Permitted values are: >> >> "smc" : SMC #0, with the register assignments specified >> in this binding. >> @@ -32,24 +33,53 @@ Main node required properties: >> "hvc" : HVC #0, with the register assignments specified >> in this binding. >> >> + - psci_version : Function ID for PSCI_VERSION operation. Required for >> + "arm,psci-0.2" compatible version or later. >> + > > While this seems sensible, I'm not sure that this needs to be mandatory. It is quite pointless to have at all if we don't make it mandatory. I would accept that it is pointless and the compatible string should always reflect the version anyway, but ARM added the call and states it is mandatory in the PSCI doc. I guess we could have mandatory for the firmware to implement, but optional in the DT binding? That seems silly though. Rob
diff --git a/Documentation/devicetree/bindings/arm/psci.txt b/Documentation/devicetree/bindings/arm/psci.txt index 433afe9..209bb04 100644 --- a/Documentation/devicetree/bindings/arm/psci.txt +++ b/Documentation/devicetree/bindings/arm/psci.txt @@ -1,16 +1,17 @@ * Power State Coordination Interface (PSCI) Firmware implementing the PSCI functions described in ARM document number -ARM DEN 0022A ("Power State Coordination Interface System Software on ARM +ARM DEN 0022B ("Power State Coordination Interface System Software on ARM processors") can be used by Linux to initiate various CPU-centric power operations. -Issue A of the specification describes functions for CPU suspend, hotplug -and migration of secure software. +Issue B of the specification describes functions for CPU suspend, hotplug, +migration of secure software, and system level reset and powerdown. Functions are invoked by trapping to the privilege level of the PSCI firmware (specified as part of the binding below) and passing arguments -in a manner similar to that specified by AAPCS: +as defined in ARM document "SMC Calling Convention" (ARM DEN 0028) in a manner +similar to that specified by AAPCS: r0 => 32-bit Function ID / return value {r1 - r3} => Parameters @@ -21,10 +22,10 @@ to #0. Main node required properties: - - compatible : Must be "arm,psci" + - compatible : Must contain "arm,psci-0.2" or "arm,psci" - - method : The method of calling the PSCI firmware. Permitted - values are: + - method : The method defines the calling convention for the PSCI + firmware. Permitted values are: "smc" : SMC #0, with the register assignments specified in this binding. @@ -32,24 +33,53 @@ Main node required properties: "hvc" : HVC #0, with the register assignments specified in this binding. + - psci_version : Function ID for PSCI_VERSION operation. Required for + "arm,psci-0.2" compatible version or later. + Main node optional properties: - - cpu_suspend : Function ID for CPU_SUSPEND operation + - cpu_suspend[-<32|64] : Function ID for CPU_SUSPEND operation + + - cpu_off : Function ID for CPU_OFF operation + + - cpu_on[-<32|64] : Function ID for CPU_ON operation + + - affinity_info[-<32|64] : Function ID for AFFINITY_INFO operation - - cpu_off : Function ID for CPU_OFF operation + - migrate[-<32|64] : Function ID for MIGRATE operation - - cpu_on : Function ID for CPU_ON operation + - migrate_info_type : Function ID for MIGRATE_INFO_TYPE operation - - migrate : Function ID for MIGRATE operation + - migrate_info_up_cpu[-<32|64] : Function ID for MIGRATE_INFO_UP_CPU operation + - system_reset : Function ID for SYSTEM_RESET operation + + - system_off : Function ID for SYSTEM_OFF operation + +Some function IDs support 32-bit and 64-bit calling conventions. If no size is +specified, then the 32-bit calling convention is used. Therefore, all function +IDs for 64-bit calling convention are required to have "-64" suffix. Use of the +"-32" suffix is recommended, but not required for backwards compatibility. Example: psci { - compatible = "arm,psci"; + compatible = "arm,psci-0.2"; method = "smc"; - cpu_suspend = <0x95c10000>; - cpu_off = <0x95c10001>; - cpu_on = <0x95c10002>; - migrate = <0x95c10003>; + psci_version = <0x84000000>; + cpu_suspend-32 = <0x84000001>; + cpu_suspend-64 = <0xc4000001>; + cpu_off = <0x84000002>; + cpu_on-32 = <0x84000003>; + cpu_on-64 = <0xc4000003>; + affinity_info-32 = <0x84000004>; + affinity_info-64 = <0xc4000004>; + migrate-32 = <0x84000005>; + migrate-64 = <0xc4000005>; + migrate_info_type = <0x84000006>; + migrate_info_up_cpu-32 = <0x84000007>; + migrate_info_up_cpu-64 = <0xc4000007>; + system_off = <0x84000008>; + system_reset = <0x84000009>; }; +