Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
IronPort-SDR: o3pvRh/zaDgSs6bHmil/KT5JaB+bVJy0PMkufzdEd2y3RLIP+GC2H5zV93gumEm+eUAGRIugH1
 1Zke1klBJ6v3wriJrvB3/DfZ58rvouPeX8XodhQuMOgtvpdpIx/bAEaepThobNnpRGpeX/Nm9r
 2RlI0Blz6SzyRsCaG5DO+rzXdFgQoZH3UqkbGupx/RsTKJ8QAxZIvf4MJI8JqniCAzKRJ/6qST
 SlJe7I2uFy3oNbAkFaSG7sv5yHIFb9+vSSzAdxTPfz2TNiYYb+ZZO5STxGViqG3ai9rz52XlG2
 Ll+8dGVomm0ttamDI0ZAIN6I
IronPort-SDR: IhuVAZBifJqI9IKuS0jMxBGdTiTGwyls+8KLoVoQxR+MZbq17NQMJCS0zCKmfv0FIyjO5ER+xU
 uKuBwqw/ciq7haWhaHEIk3iVr3tST6zhbS0LPkrpPy5EeDNgiqX3bVX278b8DCIcf+TvF8yB8P
 od3lJ8UVXt6YkRV6SQonasIb1Py4zUs+W0nWwynSyOsV5qt3dj3wBaQRQ4ULYfxBfcrLk4MgDr
 GcCUZHd/G16Iswe9a6I/0aEFqnhvrprV/s/sj7igbIhsMn3J1LW6/qV9jVc8tkJm/NekKVyY4o
 Fr0=
From:   Atish Patra <atish.patra@wdc.com>
To:     linux-kernel@vger.kernel.org
Cc:     Atish Patra <atish.patra@wdc.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Anup Patel <anup@brainfault.org>,
        Ard Biesheuvel <ard.biesheuvel@linaro.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        devicetree@vger.kernel.org,
        Dmitriy Cherkasov <dmitriy@oss-tech.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Ingo Molnar <mingo@kernel.org>,
        Jeremy Linton <jeremy.linton@arm.com>,
        Johan Hovold <johan@kernel.org>,
        linux-riscv@lists.infradead.org,
        Mark Rutland <mark.rutland@arm.com>,
        Morten Rasmussen <morten.rasmussen@arm.com>,
        Otto Sabart <ottosabart@seberm.com>,
        Palmer Dabbelt <palmer@sifive.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        "Peter Zijlstra (Intel)" <peterz@infradead.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Sudeep Holla <sudeep.holla@arm.com>,
        Will Deacon <will.deacon@arm.com>
Subject: [RFT/RFC PATCH v3 0/5] Unify CPU topology across ARM & RISC-V 
Date:   Wed, 20 Mar 2019 16:48:01 -0700
Message-Id: <20190320234806.19748-1-atish.patra@wdc.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

The cpu-map DT entry in ARM can describe the CPU topology in much better
way compared to other existing approaches. RISC-V can easily adopt this
binding to represent its 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 significant functional changes in the moved 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.

There was an opportunity to unify topology data structure for ARM32 done
by patch 3/4. But, I refrained from making any other changes as I am not
very well versed with original intention for some functions that
are present in arch_topology.c. I hope this patch series can be served
as a baseline for such changes in the future.

The patches have been tested for RISC-V and compile tested for ARM64,
ARM32 & x86.

The socket change[2] is also now part of this series.

[1] https://lkml.org/lkml/2018/11/6/19
[2] https://lkml.org/lkml/2018/11/7/918

QEMU changes for RISC-V topology are available at

https://github.com/atishp04/qemu/tree/riscv_topology_dt

HiFive Unleashed DT with topology node is available here.
https://github.com/atishp04/opensbi/tree/HiFive_unleashed_topology

It can be verified with OpenSBI with following additional compile time
option.

FW_PAYLOAD_FDT="unleashed_topology.dtb"

Changes from v2->v3
1. Cover letter update with experiment DT for topology changes.
2. Added the patch for [2].

Changes from v1->v2
1. ARM32 can now use the common code as well.

Atish Patra (4):
dt-binding: cpu-topology: Move cpu-map to a common binding.
cpu-topology: Move cpu topology code to common code.
arm: Use common cpu_topology
RISC-V: Parse cpu topology during boot.

Sudeep Holla (1):
Documentation: DT: arm: add support for sockets defining package
boundaries

.../topology.txt => cpu/cpu-topology.txt}     | 134 ++++++--
arch/arm/include/asm/topology.h               |  22 +-
arch/arm/kernel/topology.c                    |  10 +-
arch/arm64/include/asm/topology.h             |  23 --
arch/arm64/kernel/topology.c                  | 303 +-----------------
arch/riscv/Kconfig                            |   1 +
arch/riscv/kernel/smpboot.c                   |   3 +
drivers/base/arch_topology.c                  | 298 ++++++++++++++++-
drivers/base/topology.c                       |   1 +
include/linux/arch_topology.h                 |  36 +++
10 files changed, 453 insertions(+), 378 deletions(-)
rename Documentation/devicetree/bindings/{arm/topology.txt => cpu/cpu-topology.txt} (66%)

--
2.21.0