Re: [RFC PATCH 1/2] arm64/cpuinfo: Move init_cpu_features() ahead of setup.c::early_fixmap_init()
From: Will Deacon <will@kernel.org>
Date: 2021-01-26 13:58:06
Also in:
lkml
On Wed, Jan 13, 2021 at 09:40:46AM +0800, Jia He wrote:
quoted hunk ↗ jump to hunk
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 <redacted> --- 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