Re: [RFC PATCH v3 4/8] arm64: Handle early CPU boot failures

From: Suzuki K. Poulose
Date: Tue Dec 15 2015 - 06:37:56 EST


On 09/12/15 09:57, Suzuki K. Poulose wrote:
A secondary CPU could fail to come online due to insufficient
capabilities and could simply die or loop in the kernel.
e.g, a CPU with no support for the selected kernel PAGE_SIZE
loops in kernel with MMU turned off.
or a hotplugged CPU which doesn't have one of the advertised
system capability will die during the activation.


#ifdef CONFIG_HOTPLUG_CPU
+ update_cpu_boot_status(CPU_KILL_ME);
/* Check if we can park ourselves */
if (cpu_ops[cpu] && cpu_ops[cpu]->cpu_die)
cpu_ops[cpu]->cpu_die(cpu);
#endif
+ update_cpu_boot_status(CPU_STUCK_IN_KERNEL);
+ __flush_dcache_area(&secondary_data, sizeof(secondary_data));

James pointed out that we don't need the explicit ___flush_dcache_area (which is a left over
from previous version). I have fixed this locally.


Thanks
Suzuki
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