Re: [PATCH] ARM: kexec: Relax SMP validation to improve DT compatibility

From: Stephen Warren
Date: Thu Feb 26 2015 - 12:20:45 EST


On 02/26/2015 03:37 AM, Geert Uytterhoeven wrote:
When trying to kexec into a new kernel on a platform where multiple CPU
cores are present, but no SMP bringup code is available yet, the
kexec_load system call fails with:

kexec_load failed: Invalid argument

The SMP test added to machine_kexec_prepare() in commit 2103f6cba61a8b8b
("ARM: 7807/1: kexec: validate CPU hotplug support") wants to prohibit
kexec on SMP platforms where it cannot disable secondary CPUs.
However, this test is too strict: if the secondary CPUs couldn't be
enabled in the first place, there's no need to disable them later at
kexec time. Hence skip the test in the absence of SMP bringup code.

This allows to add all CPU cores to the DTS from the beginning, without
having to implement SMP bringup first, improving DT compatibility.

Acked-by: Stephen Warren <swarren@xxxxxxxxxx>
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