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@xxxxxxxxxx>
Reviewed-by: Bob Picco <bob.picco@xxxxxxxxxx>
Reviewed-by: Vijay Kumar <vijay.ac.kumar@xxxxxxxxxx>
---
arch/sparc/include/asm/smp_64.h | 2 ++
arch/sparc/kernel/setup_64.c | 1 +
arch/sparc/kernel/smp_64.c | 14 ++++++++++++++
3 files changed, 17 insertions(+), 0 deletions(-)
diff --git a/arch/sparc/include/asm/smp_64.h b/arch/sparc/include/asm/smp_64.h
index 26d9e77..ce2233f 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);
@@ -72,6 +73,7 @@ void __cpu_die(unsigned int cpu);
#define smp_fill_in_sib_core_maps() do { } while (0)
#define smp_fetch_global_regs() do { } while (0)
#define smp_fetch_global_pmu() do { } while (0)
+#define smp_fill_in_cpu_possible_map() do { } while (0)
#endif /* !(CONFIG_SMP) */
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;
--
1.7.1
--
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