From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Date: Thu, 26 Feb 2015 17:21:19 +0000 Subject: Re: [PATCH] ARM: kexec: Relax SMP validation to improve DT compatibility Message-Id: <54EF560F.3070805@wwwdotorg.org> List-Id: References: <1424947028-7438-1-git-send-email-geert+renesas@glider.be> In-Reply-To: <1424947028-7438-1-git-send-email-geert+renesas@glider.be> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-arm-kernel@lists.infradead.org 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 From mboxrd@z Thu Jan 1 00:00:00 1970 From: swarren@wwwdotorg.org (Stephen Warren) Date: Thu, 26 Feb 2015 10:21:19 -0700 Subject: [PATCH] ARM: kexec: Relax SMP validation to improve DT compatibility In-Reply-To: <1424947028-7438-1-git-send-email-geert+renesas@glider.be> References: <1424947028-7438-1-git-send-email-geert+renesas@glider.be> Message-ID: <54EF560F.3070805@wwwdotorg.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH] ARM: kexec: Relax SMP validation to improve DT compatibility Date: Thu, 26 Feb 2015 10:21:19 -0700 Message-ID: <54EF560F.3070805@wwwdotorg.org> References: <1424947028-7438-1-git-send-email-geert+renesas@glider.be> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1424947028-7438-1-git-send-email-geert+renesas@glider.be> Sender: linux-kernel-owner@vger.kernel.org To: Geert Uytterhoeven , Russell King , Magnus Damm , Stephen Warren Cc: linux-arm-kernel@lists.infradead.org, linux-sh@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: devicetree@vger.kernel.org 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