From mboxrd@z Thu Jan 1 00:00:00 1970 From: Santosh Subject: Re: [PATCH 00/11] Add L2 cache cleaning to generic CPU suspend Date: Sat, 03 Sep 2011 22:06:38 +0530 Message-ID: <4E625796.1020109@ti.com> References: <20110901124752.GE29729@n2100.arm.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from na3sys009aog123.obsmtp.com ([74.125.149.149]:57537 "EHLO na3sys009aog123.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752134Ab1ICQgo (ORCPT ); Sat, 3 Sep 2011 12:36:44 -0400 Received: by gxk7 with SMTP id 7so3302511gxk.21 for ; Sat, 03 Sep 2011 09:36:43 -0700 (PDT) In-Reply-To: <20110901124752.GE29729@n2100.arm.linux.org.uk> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Russell King - ARM Linux Cc: linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org On Thursday 01 September 2011 06:17 PM, Russell King - ARM Linux wrote: > Some systems (such as OMAP) preserve the L2 cache across a suspend/ > resume cycle. This means they do not perform L2 cache maintanence > in their suspend finisher function. > > However, the side effect is that the saved CPU state is not readable > by the resume code because it is sitting in the L2 cache. > > This patch series adds L2 cache cleaning to the generic CPU suspend/ > resume support code, making it possible to use this on systems with > L2 cache enabled without having to clean/invalidate the entire L2 > cache. > > We also add a separate page table, allocated at boot time, for the > resume process to use so we don't have to fiddle about with tweaking > entries in the current processes page table. Moreover, the current > processes page table may be in use by another CPU in the system if > these paths are used from cpuidle or hotplug, so changing the page > table is technically unsound. > > Overall, this makes it possible for OMAP4 systems to use this code. > > The first four patches in this set are already merged into Linus' tree > as bug fixes, and are included here for completeness given that the > kernel.org infrastructure is currently offline. > > This has (so far) only been tested on OMAP4. Further testing on OMAP3 > and Assabet will follow. Thanks a lot Russell for this series. I have tested the entire series with OMAP4 S2R and CPUIDLE and it works great. Tested-by: Santosh Shilimkar Regards Santosh From mboxrd@z Thu Jan 1 00:00:00 1970 From: santosh.shilimkar@ti.com (Santosh) Date: Sat, 03 Sep 2011 22:06:38 +0530 Subject: [PATCH 00/11] Add L2 cache cleaning to generic CPU suspend In-Reply-To: <20110901124752.GE29729@n2100.arm.linux.org.uk> References: <20110901124752.GE29729@n2100.arm.linux.org.uk> Message-ID: <4E625796.1020109@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thursday 01 September 2011 06:17 PM, Russell King - ARM Linux wrote: > Some systems (such as OMAP) preserve the L2 cache across a suspend/ > resume cycle. This means they do not perform L2 cache maintanence > in their suspend finisher function. > > However, the side effect is that the saved CPU state is not readable > by the resume code because it is sitting in the L2 cache. > > This patch series adds L2 cache cleaning to the generic CPU suspend/ > resume support code, making it possible to use this on systems with > L2 cache enabled without having to clean/invalidate the entire L2 > cache. > > We also add a separate page table, allocated at boot time, for the > resume process to use so we don't have to fiddle about with tweaking > entries in the current processes page table. Moreover, the current > processes page table may be in use by another CPU in the system if > these paths are used from cpuidle or hotplug, so changing the page > table is technically unsound. > > Overall, this makes it possible for OMAP4 systems to use this code. > > The first four patches in this set are already merged into Linus' tree > as bug fixes, and are included here for completeness given that the > kernel.org infrastructure is currently offline. > > This has (so far) only been tested on OMAP4. Further testing on OMAP3 > and Assabet will follow. Thanks a lot Russell for this series. I have tested the entire series with OMAP4 S2R and CPUIDLE and it works great. Tested-by: Santosh Shilimkar Regards Santosh