arm64: apply alternatives for !SMP kernels (137650aa) · Commits · 戴 / test

Currently we only perform alternative patching for kernels built with CONFIG_SMP, as we call apply_alternatives_all() in smp.c, which is only built for CONFIG_SMP. Thus !SMP kernels may not have necessary alternatives patched in. This patch ensures that we call apply_alternatives_all() once all CPUs are booted, even for !SMP kernels, by having the smp_init_cpus() stub call this for !SMP kernels via up_late_init. A new wrapper, do_post_cpus_up_work, is added so we can hook other calls here later (e.g. boot mode logging). Cc: Andre Przywara <andre.przywara@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Fixes: ("arm64: add alternative runtime patching") Tested-by:

Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by:

Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by:

Mark Rutland <mark.rutland@arm.com> Signed-off-by:

Will Deacon <will.deacon@arm.com>

arch/arm64/Kconfig

+4 −0

Original line number	Diff line number	Diff line
		@@ -470,6 +470,10 @@ config HOTPLUG_CPU

		source kernel/Kconfig.preempt

		config UP_LATE_INIT
		def_bool y
		depends on !SMP

		config HZ
		int
		default 100

arch/arm64/include/asm/smp_plat.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -40,4 +40,6 @@ static inline u32 mpidr_hash_size(void)
		extern u64 __cpu_logical_map[NR_CPUS];
		#define cpu_logical_map(cpu) __cpu_logical_map[cpu]

		void __init do_post_cpus_up_work(void);

		#endif /* __ASM_SMP_PLAT_H */

arch/arm64/kernel/setup.c

+12 −0

Original line number	Diff line number	Diff line
		@@ -207,6 +207,18 @@ static void __init smp_build_mpidr_hash(void)
		}
		#endif

		void __init do_post_cpus_up_work(void)
		{
		apply_alternatives_all();
		}

		#ifdef CONFIG_UP_LATE_INIT
		void __init up_late_init(void)
		{
		do_post_cpus_up_work();
		}
		#endif /* CONFIG_UP_LATE_INIT */

		static void __init setup_processor(void)
		{
		struct cpu_info *cpu_info;

arch/arm64/kernel/smp.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -309,7 +309,7 @@ void cpu_die(void)
		void __init smp_cpus_done(unsigned int max_cpus)
		{
		pr_info("SMP: Total of %d processors activated.\n", num_online_cpus());
		apply_alternatives_all();
		do_post_cpus_up_work();
		}

		void __init smp_prepare_boot_cpu(void)

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