Re: [PATCH v2 5/8] arm64: Create cache sysfs directory without ACPI PPTT for hardware prefetch control

From: Rob Herring <robh@kernel.org>
To: Kohei Tarumizu <tarumizu.kohei@fujitsu.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	X86 ML <x86@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
	linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 5/8] arm64: Create cache sysfs directory without ACPI PPTT for hardware prefetch control
Date: Wed, 30 Mar 2022 17:14:49 -0500	[thread overview]
Message-ID: <CAL_Jsq+TvPMZLeBx5Xi4pUNKueGUG9pSTXO2DzWov401w4a6Qw@mail.gmail.com> (raw)
In-Reply-To: <20220311101940.3403607-6-tarumizu.kohei@fujitsu.com>

On Fri, Mar 11, 2022 at 4:23 AM Kohei Tarumizu
<tarumizu.kohei@fujitsu.com> wrote:
>
> This patch create a cache sysfs directory without ACPI PPTT if the
> CONFIG_HWPF_CONTROL is true.
>
> Hardware prefetch control driver need cache sysfs directory and cache
> level/type information. In ARM processor, these information can be
> obtained from the register even without PPTT.

What registers? CCSIDR register is no longer used. You must use DT or PPTT.

> Therefore, we set the
> cpu_map_populated to true to create cache sysfs directory if the
> machine doesn't have PPTT.
>
> Signed-off-by: Kohei Tarumizu <tarumizu.kohei@fujitsu.com>
> ---
>  arch/arm64/kernel/cacheinfo.c | 29 +++++++++++++++++++++++++++++
>  1 file changed, 29 insertions(+)