From 9b2f753ec23710aa32c0d837d2499db92fe9115b Mon Sep 17 00:00:00 2001 From: Atish Patra Date: Thu, 15 Sep 2016 14:54:40 -0600 Subject: [PATCH] sparc64: Fix cpu_possible_mask if nr_cpus is set 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 Reviewed-by: Bob Picco Reviewed-by: Vijay Kumar Signed-off-by: David S. Miller --- arch/sparc/include/asm/smp_64.h | 1 + arch/sparc/kernel/setup_64.c | 1 + arch/sparc/kernel/smp_64.c | 14 ++++++++++++++ 3 files changed, 16 insertions(+) diff --git a/arch/sparc/include/asm/smp_64.h b/arch/sparc/include/asm/smp_64.h index 26d9e77..87b0575 100644 --- a/arch/sparc/include/asm/smp_64.h +++ b/arch/sparc/include/asm/smp_64.h @@ -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); diff --git a/arch/sparc/kernel/setup_64.c b/arch/sparc/kernel/setup_64.c index 599f120..f32cfe8 100644 --- a/arch/sparc/kernel/setup_64.c +++ b/arch/sparc/kernel/setup_64.c @@ -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; diff --git a/arch/sparc/kernel/smp_64.c b/arch/sparc/kernel/smp_64.c index 8a6151a..d3035ba 100644 --- a/arch/sparc/kernel/smp_64.c +++ b/arch/sparc/kernel/smp_64.c @@ -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; -- 2.7.4