From: Will Deacon <will@kernel.org>
To: Jia He <justin.he@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
Kefeng Wang <wangkefeng.wang@huawei.com>,
Gavin Shan <gshan@redhat.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Ard Biesheuvel <ardb@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Anshuman Khandual <anshuman.khandual@arm.com>,
Richard Henderson <richard.henderson@linaro.org>,
linux-kernel@vger.kernel.org,
"Gustavo A. R. Silva" <gustavoars@kernel.org>,
Mark Brown <broonie@kernel.org>,
Cristian Marussi <cristian.marussi@arm.com>,
Mike Rapoport <rppt@kernel.org>, Marc Zyngier <maz@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Steven Price <steven.price@arm.com>,
Dave Martin <Dave.Martin@arm.com>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [RFC PATCH 1/2] arm64/cpuinfo: Move init_cpu_features() ahead of setup.c::early_fixmap_init()
Date: Tue, 26 Jan 2021 13:57:13 +0000 [thread overview]
Message-ID: <20210126135712.GA29956@willie-the-truck> (raw)
In-Reply-To: <20210113014047.14371-2-justin.he@arm.com>
On Wed, Jan 13, 2021 at 09:40:46AM +0800, Jia He wrote:
> Move init_cpu_features() ahead of setup_arch()->early_fixmap_init(), which
> is the preparation work for checking the condition to assign
> arm64_use_ng_mappings as cpus_have_const_cap(ARM64_UNMAP_KERNEL_AT_EL0).
>
> Besides, jump_label_init() is also moved ahead because
> cpus_have_const_cap() depends on static key enable api.
>
> Percpu helpers should be avoided in cpuinfo_store_boot_cpu() before percpu
> init at main.c::setup_per_cpu_areas()
>
> Signed-off-by: Jia He <justin.he@arm.com>
> ---
> arch/arm64/include/asm/cpu.h | 1 +
> arch/arm64/kernel/cpuinfo.c | 13 ++++++++++---
> arch/arm64/kernel/setup.c | 14 +++++++++-----
> arch/arm64/kernel/smp.c | 3 +--
> 4 files changed, 21 insertions(+), 10 deletions(-)
>
> diff --git a/arch/arm64/include/asm/cpu.h b/arch/arm64/include/asm/cpu.h
> index 7faae6ff3ab4..59f36f5e3c04 100644
> --- a/arch/arm64/include/asm/cpu.h
> +++ b/arch/arm64/include/asm/cpu.h
> @@ -63,6 +63,7 @@ DECLARE_PER_CPU(struct cpuinfo_arm64, cpu_data);
>
> void cpuinfo_store_cpu(void);
> void __init cpuinfo_store_boot_cpu(void);
> +void __init save_boot_cpuinfo_data(void);
>
> void __init init_cpu_features(struct cpuinfo_arm64 *info);
> void update_cpu_features(int cpu, struct cpuinfo_arm64 *info,
> diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
> index 77605aec25fe..f8de5b8bae20 100644
> --- a/arch/arm64/kernel/cpuinfo.c
> +++ b/arch/arm64/kernel/cpuinfo.c
> @@ -413,9 +413,16 @@ void cpuinfo_store_cpu(void)
>
> void __init cpuinfo_store_boot_cpu(void)
> {
> - struct cpuinfo_arm64 *info = &per_cpu(cpu_data, 0);
> - __cpuinfo_store_cpu(info);
> + __cpuinfo_store_cpu(&boot_cpu_data);
>
> - boot_cpu_data = *info;
> init_cpu_features(&boot_cpu_data);
> }
> +
> +void __init save_boot_cpuinfo_data(void)
> +{
> + struct cpuinfo_arm64 *info;
> +
> + set_my_cpu_offset(per_cpu_offset(smp_processor_id()));
> + info = &per_cpu(cpu_data, 0);
> + *info = boot_cpu_data;
> +}
> diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
> index 1a57a76e1cc2..e078ab068f3b 100644
> --- a/arch/arm64/kernel/setup.c
> +++ b/arch/arm64/kernel/setup.c
> @@ -297,16 +297,20 @@ void __init __no_sanitize_address setup_arch(char **cmdline_p)
> */
> arm64_use_ng_mappings = kaslr_requires_kpti();
>
> - early_fixmap_init();
> - early_ioremap_init();
> -
> - setup_machine_fdt(__fdt_pointer);
> -
> /*
> * Initialise the static keys early as they may be enabled by the
> * cpufeature code and early parameters.
> */
> jump_label_init();
I don't think your patch changes this, but afaict jump_label_init() uses
per-cpu variables via cpus_read_lock(), yet we don't initialise our offset
until later on. Any idea how that works?
Will
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-01-26 13:59 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-13 1:40 [RFC PATCH 0/2] Avoid booting stall caused by Jia He
2021-01-13 1:40 ` [RFC PATCH 1/2] arm64/cpuinfo: Move init_cpu_features() ahead of setup.c::early_fixmap_init() Jia He
2021-01-26 13:57 ` Will Deacon [this message]
2021-01-26 14:11 ` Mark Rutland
2021-01-13 1:40 ` [RFC PATCH 2/2] arm64: kpti: Update arm64_use_ng_mappings before pagetable mapping Jia He
2021-01-26 14:14 ` Will Deacon
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210126135712.GA29956@willie-the-truck \
--to=will@kernel.org \
--cc=Dave.Martin@arm.com \
--cc=akpm@linux-foundation.org \
--cc=anshuman.khandual@arm.com \
--cc=ardb@kernel.org \
--cc=broonie@kernel.org \
--cc=catalin.marinas@arm.com \
--cc=cristian.marussi@arm.com \
--cc=gshan@redhat.com \
--cc=gustavoars@kernel.org \
--cc=justin.he@arm.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=maz@kernel.org \
--cc=richard.henderson@linaro.org \
--cc=rppt@kernel.org \
--cc=steven.price@arm.com \
--cc=suzuki.poulose@arm.com \
--cc=wangkefeng.wang@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox