[RFC 0/3] Unify CPU topology across ARM64 & RISC-V
- Date: Thu, 8 Nov 2018 17:50:06 -0800
- From: Atish Patra <atish.patra@xxxxxxx>
- Subject: [RFC 0/3] Unify CPU topology across ARM64 & RISC-V
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 .
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
The socket changes can be merged on top of this series or vice
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