Messages in this thread | | | From | Atish Patra <> | Subject | [RFC 0/3] Unify CPU topology across ARM64 & RISC-V | Date | Thu, 8 Nov 2018 17:50:06 -0800 |
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The cpu-map DT entry in ARM64 can describe the CPU topology in much better way compared to other existing approaches. RISC-V can easily adopt this binding to represent it's own CPU topology. Thus, both cpu-map DT binding and topology parsing code can be moved to a common location so that RISC-V or any other architecture can leverage that.
The relevant discussion regarding unifying cpu topology can be found in [1].
arch_topology seems to be a perfect place to move the common code. I have not introduced any functional changes in the moved to code. The only downside in this approach is that the capacity code will be executed for RISC-V as well. But, it will exit immediately after not able to find the appropriate DT node. If the overhead is considered too much, we can always compile out capacity related functions under a different config for the architectures that do not support them.
The patches have been tested for RISC-V and compile tested for ARM64.
The socket changes[2] can be merged on top of this series or vice versa.
[1] https://lkml.org/lkml/2018/11/6/19 [2] https://lkml.org/lkml/2018/11/7/918
Atish Patra (3): dt-binding: cpu-topology: Move cpu-map to a common binding. cpu-topology: Move cpu topology code to common code. RISC-V: Parse cpu topology during boot.
Documentation/devicetree/bindings/arm/topology.txt | 475 ------------------- .../devicetree/bindings/cpu/cpu-topology.txt | 526 +++++++++++++++++++++ arch/arm64/include/asm/topology.h | 23 +- arch/arm64/kernel/topology.c | 305 +----------- arch/riscv/Kconfig | 1 + arch/riscv/kernel/smpboot.c | 6 +- drivers/base/arch_topology.c | 303 ++++++++++++ include/linux/arch_topology.h | 23 + include/linux/topology.h | 1 + 9 files changed, 864 insertions(+), 799 deletions(-) delete mode 100644 Documentation/devicetree/bindings/arm/topology.txt create mode 100644 Documentation/devicetree/bindings/cpu/cpu-topology.txt
-- 2.7.4
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