From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH V4 00/27] C-SKY(csky) Linux Kernel Port Date: Wed, 12 Sep 2018 16:30:36 +0200 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Guo Ren Cc: linux-arch , Linux Kernel Mailing List , Thomas Gleixner , Daniel Lezcano , Jason Cooper , DTML , andrea.parri@amarulasolutions.com, Peter Zijlstra , c-sky_gcc_upstream@c-sky.com, gnu-csky@mentor.com, Thomas Petazzoni , wbx@uclibc-ng.org, Greentime Hu , Stephen Rothwell List-Id: linux-arch.vger.kernel.org On Wed, Sep 12, 2018 at 3:25 PM Guo Ren wrote: > > This is the 3th version patchset to add the Linux kernel port for C-SKY(csky). > Thanks to everyone who provided feedback on the previous version. > > This patchset adds architecture support to Linux for C-SKY's 32-bit embedded > CPU cores and the patches are based on linux-4.18.4 > > There are two ABI versions with several CPU cores in this patchset: > ABIv1: ck610 (16-bit instruction, 32-bit data path, VIPT Cache ...) > ABIv2: ck807 ck810 ck860 (16/32-bit variable length instruction, PIPT Cache, > SMP ...) > > More information: http://en.c-sky.com This looks good to me overall. I think a good next step would be to get the port included in linux-next, by preparing a git tree with all the patches and asking Stephen Rothwell to include it there. Further comments on the architecture port itself can be done on top of the existing patches. I would suggest you base the git tree on an -rc release (either 4.19-rc1 or 4.19-rc3) and then never rebase again. You have included a couple of drivers in the submission: two timer and two irqchip drivers. Please leave those out for the moment, and either have them merged through the respective subsystem trees, or get an Ack from the maintainers to merge them through your tree. I notice that a lot of the patches have no changeset comments on them. You should fix that and make a habit of describing every single patch with a few sentences, even if it seems obvious to you. Have a look at the changeset descriptions for the nds32 and riscv architectures when they got merged. One big question for me is what to do about time_t. Deepa and I are in the process of finalizing the system call ABI for 32-bit architectures with 64-bit time_t, but we are not done yet and it won't be complete for 4.20. If you target 4.21, that could be a chance to make csky the first architecture to only need the 64-bit time_t interface, with the corresponding user space changes. Arnd From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-f196.google.com ([209.85.216.196]:39113 "EHLO mail-qt0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726672AbeILTfk (ORCPT ); Wed, 12 Sep 2018 15:35:40 -0400 MIME-Version: 1.0 References: In-Reply-To: From: Arnd Bergmann Date: Wed, 12 Sep 2018 16:30:36 +0200 Message-ID: Subject: Re: [PATCH V4 00/27] C-SKY(csky) Linux Kernel Port Content-Type: text/plain; charset="UTF-8" Sender: linux-arch-owner@vger.kernel.org List-ID: To: Guo Ren Cc: linux-arch , Linux Kernel Mailing List , Thomas Gleixner , Daniel Lezcano , Jason Cooper , DTML , andrea.parri@amarulasolutions.com, Peter Zijlstra , c-sky_gcc_upstream@c-sky.com, gnu-csky@mentor.com, Thomas Petazzoni , wbx@uclibc-ng.org, Greentime Hu , Stephen Rothwell Message-ID: <20180912143036.zXaJ8mGNwPfeIKIZd4U5CNjj-7qtyvO5uPpeCxRI1Qs@z> On Wed, Sep 12, 2018 at 3:25 PM Guo Ren wrote: > > This is the 3th version patchset to add the Linux kernel port for C-SKY(csky). > Thanks to everyone who provided feedback on the previous version. > > This patchset adds architecture support to Linux for C-SKY's 32-bit embedded > CPU cores and the patches are based on linux-4.18.4 > > There are two ABI versions with several CPU cores in this patchset: > ABIv1: ck610 (16-bit instruction, 32-bit data path, VIPT Cache ...) > ABIv2: ck807 ck810 ck860 (16/32-bit variable length instruction, PIPT Cache, > SMP ...) > > More information: http://en.c-sky.com This looks good to me overall. I think a good next step would be to get the port included in linux-next, by preparing a git tree with all the patches and asking Stephen Rothwell to include it there. Further comments on the architecture port itself can be done on top of the existing patches. I would suggest you base the git tree on an -rc release (either 4.19-rc1 or 4.19-rc3) and then never rebase again. You have included a couple of drivers in the submission: two timer and two irqchip drivers. Please leave those out for the moment, and either have them merged through the respective subsystem trees, or get an Ack from the maintainers to merge them through your tree. I notice that a lot of the patches have no changeset comments on them. You should fix that and make a habit of describing every single patch with a few sentences, even if it seems obvious to you. Have a look at the changeset descriptions for the nds32 and riscv architectures when they got merged. One big question for me is what to do about time_t. Deepa and I are in the process of finalizing the system call ABI for 32-bit architectures with 64-bit time_t, but we are not done yet and it won't be complete for 4.20. If you target 4.21, that could be a chance to make csky the first architecture to only need the 64-bit time_t interface, with the corresponding user space changes. Arnd