Received-SPF: pass (google.com: domain of linux-kernel+bounces-159778-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45d1:ec00::1 as permitted sender) client-ip=2604:1380:45d1:ec00::1;
Message-ID: <566817ae-90f0-4ec9-b54e-b9fdb635119e@redhat.com>
Date: Fri, 26 Apr 2024 19:23:19 +1000
Precedence: bulk
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH v7 01/16] ACPI: processor: Simplify initial onlining to
 use same path for cold and hotplug
Content-Language: en-US
To: Jonathan Cameron <Jonathan.Cameron@huawei.com>,
 Thomas Gleixner <tglx@linutronix.de>, Peter Zijlstra <peterz@infradead.org>,
 linux-pm@vger.kernel.org, loongarch@lists.linux.dev,
 linux-acpi@vger.kernel.org, linux-arch@vger.kernel.org,
 linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
 kvmarm@lists.linux.dev, x86@kernel.org, Russell King
 <linux@armlinux.org.uk>, "Rafael J . Wysocki" <rafael@kernel.org>,
 Miguel Luis <miguel.luis@oracle.com>, James Morse <james.morse@arm.com>,
 Salil Mehta <salil.mehta@huawei.com>,
 Jean-Philippe Brucker <jean-philippe@linaro.org>,
 Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
 Dave Hansen <dave.hansen@linux.intel.com>, linuxarm@huawei.com,
 justin.he@arm.com, jianyong.wu@arm.com
References: <20240418135412.14730-1-Jonathan.Cameron@huawei.com>
 <20240418135412.14730-2-Jonathan.Cameron@huawei.com>
From: Gavin Shan <gshan@redhat.com>
In-Reply-To: <20240418135412.14730-2-Jonathan.Cameron@huawei.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit

On 4/18/24 23:53, Jonathan Cameron wrote:
> Separate code paths, combined with a flag set in acpi_processor.c to
> indicate a struct acpi_processor was for a hotplugged CPU ensured that
> per CPU data was only set up the first time that a CPU was initialized.
> This appears to be unnecessary as the paths can be combined by letting
> the online logic also handle any CPUs online at the time of driver load.
> 
> Motivation for this change, beyond simplification, is that ARM64
> virtual CPU HP uses the same code paths for hotplug and cold path in
> acpi_processor.c so had no easy way to set the flag for hotplug only.
> Removing this necessity will enable ARM64 vCPU HP to reuse the existing
> code paths.
> 
> Leave noisy pr_info() in place but update it to not state the CPU
> was hotplugged.
> 
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> 
> ---
> v7: No change.
> v6: New patch.
> RFT: I have very limited test resources for x86 and other
> architectures that may be affected by this change.
> ---
>   drivers/acpi/acpi_processor.c   |  1 -
>   drivers/acpi/processor_driver.c | 44 ++++++++++-----------------------
>   include/acpi/processor.h        |  2 +-
>   3 files changed, 14 insertions(+), 33 deletions(-)
> 

Reviewed-by: Gavin Shan <gshan@redhat.com>