From: atish.patra@wdc.com (Atish Patra) To: linux-riscv@lists.infradead.org Subject: [RFC 0/3] Unify CPU topology across ARM64 & RISC-V Date: Thu, 8 Nov 2018 17:50:06 -0800 [thread overview] Message-ID: <1541728209-3224-1-git-send-email-atish.patra@wdc.com> (raw) 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
WARNING: multiple messages have this Message-ID (diff)
From: Atish Patra <atish.patra@wdc.com> To: linux-kernel@vger.kernel.org Cc: mark.rutland@arm.com, devicetree@vger.kernel.org, Damien.LeMoal@wdc.com, juri.lelli@arm.com, anup@brainfault.org, palmer@sifive.com, jeremy.linton@arm.com, atish.patra@wdc.com, robh+dt@kernel.org, sudeep.holla@arm.com, mick@ics.forth.gr, linux-riscv@lists.infradead.org, linux-arm-kernel@lists.infradead.org Subject: [RFC 0/3] Unify CPU topology across ARM64 & RISC-V Date: Thu, 8 Nov 2018 17:50:06 -0800 [thread overview] Message-ID: <1541728209-3224-1-git-send-email-atish.patra@wdc.com> (raw) Message-ID: <20181109015006.mPKfMT5CmxYGJTd3NEbAWVgkrGxNndcUwbH7kc4rtHM@z> (raw) 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 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv
next reply other threads:[~2018-11-09 1:50 UTC|newest] Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-11-09 1:50 Atish Patra [this message] 2018-11-09 1:50 ` [RFC 0/3] Unify CPU topology across ARM64 & RISC-V Atish Patra 2018-11-09 1:50 ` [RFC 1/3] dt-binding: cpu-topology: Move cpu-map to a common binding Atish Patra 2018-11-09 1:50 ` Atish Patra 2018-11-17 16:32 ` Rob Herring 2018-11-17 16:32 ` Rob Herring 2018-11-19 17:57 ` Atish Patra 2018-11-19 17:57 ` Atish Patra 2018-11-09 1:50 ` [RFC 2/3] cpu-topology: Move cpu topology code to common code Atish Patra 2018-11-09 1:50 ` Atish Patra 2018-11-09 1:50 ` [RFC 3/3] RISC-V: Parse cpu topology during boot Atish Patra 2018-11-09 1:50 ` Atish Patra 2018-11-15 18:31 ` [RFC 0/3] Unify CPU topology across ARM64 & RISC-V Jeffrey Hugo 2018-11-15 18:31 ` Jeffrey Hugo 2018-11-19 17:46 ` Atish Patra 2018-11-19 17:46 ` Atish Patra 2018-11-20 11:11 ` Sudeep Holla 2018-11-20 11:11 ` Sudeep Holla 2018-11-20 15:28 ` Jeffrey Hugo 2018-11-20 15:28 ` Jeffrey Hugo
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