sparc64: Fix cpu_possible_mask if nr_cpus is set (9b2f753e) · Commits · 戴 / test

If kernel boot parameter nr_cpus is set, it should define the number of CPUs that can ever be available in the system i.e. cpu_possible_mask. setup_nr_cpu_ids() overrides the nr_cpu_ids based on the cpu_possible_mask during kernel initialization. If cpu_possible_mask is not set based on the nr_cpus value, earlier part of the kernel would be initialized using nr_cpus value leading to a kernel crash. Set cpu_possible_mask based on nr_cpus value. Thus setup_nr_cpu_ids() becomes redundant and does not corrupt nr_cpu_ids value. Signed-off-by:

Atish Patra <atish.patra@oracle.com> Reviewed-by:

Bob Picco <bob.picco@oracle.com> Reviewed-by:

Vijay Kumar <vijay.ac.kumar@oracle.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

arch/sparc/include/asm/smp_64.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -43,6 +43,7 @@ void arch_send_call_function_ipi_mask(const struct cpumask *mask);
		int hard_smp_processor_id(void);
		#define raw_smp_processor_id() (current_thread_info()->cpu)

		void smp_fill_in_cpu_possible_map(void);
		void smp_fill_in_sib_core_maps(void);
		void cpu_play_dead(void);

arch/sparc/kernel/setup_64.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -650,6 +650,7 @@ void __init setup_arch(char **cmdline_p)

		paging_init();
		init_sparc64_elf_hwcap();
		smp_fill_in_cpu_possible_map();
		}

		extern int stop_a_enabled;

arch/sparc/kernel/smp_64.c

+14 −0

Original line number	Diff line number	Diff line
		@@ -1227,6 +1227,20 @@ void __init smp_setup_processor_id(void)
		xcall_deliver_impl = hypervisor_xcall_deliver;
		}

		void __init smp_fill_in_cpu_possible_map(void)
		{
		int possible_cpus = num_possible_cpus();
		int i;

		if (possible_cpus > nr_cpu_ids)
		possible_cpus = nr_cpu_ids;

		for (i = 0; i < possible_cpus; i++)
		set_cpu_possible(i, true);
		for (; i < NR_CPUS; i++)
		set_cpu_possible(i, false);
		}

		void smp_fill_in_sib_core_maps(void)
		{
		unsigned int i;

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