- 28 5月, 2014 3 次提交
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由 Paul Burton 提交于
This patch adds code to generate entry & exit code for various low power states available on systems based around the MIPS Coherent Processing System architecture (ie. those with a Coherence Manager, Global Interrupt Controller & for >=CM2 a Cluster Power Controller). States supported are: - Non-coherent wait. This state first leaves the coherent domain and then executes a regular MIPS wait instruction. Power savings are found from the elimination of coherency interventions between the core and any other coherent requestors in the system. - Clock gated. This state leaves the coherent domain and then gates the clock input to the core. This removes all dynamic power from the core but leaves the core at the mercy of another to restart its clock. Register state is preserved, but the core can not service interrupts whilst its clock is gated. - Power gated. This deepest state removes all power input to the core. All register state is lost and the core will restart execution from its BEV when another core powers it back up. Because register state is lost this state requires cooperation with the CONFIG_MIPS_CPS SMP implementation in order for the core to exit the state successfully. The code will detect which states are available on the current system during boot & generate the entry/exit code for those states. This will be used by cpuidle & hotplug implementations. Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
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由 Paul Burton 提交于
The core power down state for cpuidle will require that the CPS SMP implementation is in use. This patch provides a mips_cps_smp_in_use function which determines whether or not the CPS SMP implementation is currently in use. Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
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由 Paul Burton 提交于
When hotplug and/or a powered down idle state are supported cases will arise where a non-zero VPE must be brought online without VPE 0, and it where multiple VPEs must be onlined simultaneously. This patch prepares for that by: - Splitting struct boot_config into core & VPE boot config structures, allocated one per core or VPE respectively. This allows for multiple VPEs to be onlined simultaneously without clobbering each others configuration. - Indicating which VPEs should be online within a core at any given time using a bitmap. This allows multiple VPEs to be brought online simultaneously and also indicates to VPE 0 whether it should halt after starting any non-zero VPEs that should be online within the core. For example if all VPEs within a core are offlined via hotplug and the user onlines the second VPE within that core: 1) The core will be powered up. 2) VPE 0 will run from the BEV (ie. mips_cps_core_entry) to initialise the core. 3) VPE 0 will start VPE 1 because its bit is set in the cores bitmap. 4) VPE 0 will halt itself because its bit is clear in the cores bitmap. - Moving the core & VPE initialisation to assembly code which does not make any use of the stack. This is because if a non-zero VPE is to be brought online in a powered down core then when VPE 0 of that core runs it may not have a valid stack, and even if it did then it's messy to run through parts of generic kernel code on VPE 0 before starting the correct VPE. Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
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- 27 3月, 2014 1 次提交
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由 Paul Burton 提交于
This patch introduces a new SMP implementation for systems implementing the MIPS Coherent Processing System architecture. The kernel will make use of the Coherence Manager, Cluster Power Controller & Global Interrupt Controller in order to detect, bring up & make use of other cores in the system. SMTC is not supported, so only a single TC per VPE in the system is used. That is, this option enables an SMVP style setup but across multiple cores. Signed-off-by: NPaul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/6362/ Patchwork: https://patchwork.linux-mips.org/patch/6611/ Patchwork: https://patchwork.linux-mips.org/patch/6651/ Patchwork: https://patchwork.linux-mips.org/patch/6652/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
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