diff options
Diffstat (limited to 'arch/arm/kernel/machine_kexec.c')
| -rw-r--r-- | arch/arm/kernel/machine_kexec.c | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/arch/arm/kernel/machine_kexec.c b/arch/arm/kernel/machine_kexec.c index 4fb074c446bf..57221e349a7c 100644 --- a/arch/arm/kernel/machine_kexec.c +++ b/arch/arm/kernel/machine_kexec.c @@ -15,6 +15,7 @@ #include <asm/mmu_context.h> #include <asm/cacheflush.h> #include <asm/mach-types.h> +#include <asm/smp_plat.h> #include <asm/system_misc.h> extern const unsigned char relocate_new_kernel[]; @@ -39,6 +40,14 @@ int machine_kexec_prepare(struct kimage *image) int i, err; /* + * Validate that if the current HW supports SMP, then the SW supports + * and implements CPU hotplug for the current HW. If not, we won't be + * able to kexec reliably, so fail the prepare operation. + */ + if (num_possible_cpus() > 1 && !platform_can_cpu_hotplug()) + return -EINVAL; + + /* * No segment at default ATAGs address. try to locate * a dtb using magic. */ @@ -73,6 +82,7 @@ void machine_crash_nonpanic_core(void *unused) crash_save_cpu(®s, smp_processor_id()); flush_cache_all(); + set_cpu_online(smp_processor_id(), false); atomic_dec(&waiting_for_crash_ipi); while (1) cpu_relax(); @@ -134,10 +144,13 @@ void machine_kexec(struct kimage *image) unsigned long reboot_code_buffer_phys; void *reboot_code_buffer; - if (num_online_cpus() > 1) { - pr_err("kexec: error: multiple CPUs still online\n"); - return; - } + /* + * This can only happen if machine_shutdown() failed to disable some + * CPU, and that can only happen if the checks in + * machine_kexec_prepare() were not correct. If this fails, we can't + * reliably kexec anyway, so BUG_ON is appropriate. + */ + BUG_ON(num_online_cpus() > 1); page_list = image->head & PAGE_MASK; |