From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Fainelli Subject: Re: [PATCH v2 0/2] arm64: Cut rebuild time when changing CONFIG_BLK_DEV_INITRD Date: Fri, 26 Oct 2018 12:05:25 -0700 Message-ID: <53ec9df5-ef2a-edc5-be1c-bca32959c0bc@gmail.com> References: <20181024193256.23734-1-f.fainelli@gmail.com> <20181025093833.GA23607@rapoport-lnx> <20181025172935.GA27364@rapoport-lnx> <1bb3bd63-a88e-b668-ea36-f0f985c0e2b1@gmail.com> <20181026110708.GA3814@rapoport-lnx> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20181026110708.GA3814@rapoport-lnx> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Mike Rapoport Cc: Rob Herring , Ard Biesheuvel , "linux-kernel@vger.kernel.org" , Catalin Marinas , Will Deacon , Arnd Bergmann , Greg Kroah-Hartman , Marc Zyngier , Olof Johansson , linux-alpha@vger.kernel.org, arcml , "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" , linux-c6x-dev@linux-c6x.org, "moderated list:H8/300 ARCHITECTURE" , linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, Linux-MIPS List-Id: devicetree@vger.kernel.org On 10/26/18 4:07 AM, Mike Rapoport wrote: > On Thu, Oct 25, 2018 at 04:07:13PM -0700, Florian Fainelli wrote: >> On 10/25/18 2:13 PM, Rob Herring wrote: >>> On Thu, Oct 25, 2018 at 12:30 PM Mike Rapoport wrote: >>>> >>>> On Thu, Oct 25, 2018 at 08:15:15AM -0500, Rob Herring wrote: >>>>> +Ard >>>>> >>>>> On Thu, Oct 25, 2018 at 4:38 AM Mike Rapoport wrote: >>>>>> >>>>>> On Wed, Oct 24, 2018 at 02:55:17PM -0500, Rob Herring wrote: >>>>>>> On Wed, Oct 24, 2018 at 2:33 PM Florian Fainelli wrote: >>>>>>>> >>>>>>>> Hi all, >>>>>>>> >>>>>>>> While investigating why ARM64 required a ton of objects to be rebuilt >>>>>>>> when toggling CONFIG_DEV_BLK_INITRD, it became clear that this was >>>>>>>> because we define __early_init_dt_declare_initrd() differently and we do >>>>>>>> that in arch/arm64/include/asm/memory.h which gets included by a fair >>>>>>>> amount of other header files, and translation units as well. >>>>>>> >>>>>> I think arm64 does not have to redefine __early_init_dt_declare_initrd(). >>>>>> Something like this might be just all we need (completely untested, >>>>>> probably it won't even compile): > > [ ... ] > >> FWIW, I am extracting the ARM implementation that parses the initrd >> early command line parameter and the "setup" code doing the page >> boundary alignment and memblock checking into a helper into lib/ that >> other architectures can re-use. So far, this removes the need for >> unicore32, arc and arm to duplicate essentially the same logic. > > Presuming you are going to need asm-generic/initrd.h for that as well, > using override for __early_init_dt_declare_initrd in arm64 version of > initrd.h might be the simplest option. What I am contemplating doing is promote phys_initrd_start/phys_initrd_size to be global variables (similar to initrd_start, initrd_end) and have a generic helper function for parsing the initrd= command line parameter and finally removing __early_init_dt_declare_initrd() because we could have early_init_dt_check_for_initrd() just populate phys_initrd_start/phys_initrd_size directly as well as initrd_start/initrd_end using __va() to preserve compatibility with architectures that rely on this. Then I would convert ARM64 to check for phys_initrd_start which is really what it is is trying to do in arch/arm64/mm/init.c::arm64_memblock_init(). Does that sound like a reasonable approach? -- Florian