From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id DCB23CF64AB for ; Thu, 20 Nov 2025 09:56:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Subject:CC:To: From:Date:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=ppSNMX2sYVnmPCHIo78O7cdSshr72jFmHEsPFp2TSzQ=; b=0lX8DZho8p8EI9W/tne8X9oGDt mfTX1DWUDvkTSYMIt41rKkBl1KTKFTA8nmQah+e6zcYbf4b4wF1mT66JpbxfH2f0JWuvUVigKmlWw EcmsjI2/t1xywJtSU9ZoefaV1qsExETjR7xhXVhQ5+Es8Ld7wnS9bdKFI3KU/qJXHdjCIrlZNgJTD 8Y+Mlmiqhid7GByH7V2Hdndd6hWabg5o2ci0XAKoVEw3vm0YJJSGPdYtKdoXLNcodfdxgFKfMlSW5 FKdXdwfk1IoXpllZ7P7+vQdazk27zR+LYXOG6JwIxmSl7ljVuh7v3HNT0TG7gjporXvJZWBWjGnVf KVrWL+Tw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vM1OM-00000006SjY-49jK; Thu, 20 Nov 2025 09:55:54 +0000 Received: from frasgout.his.huawei.com ([185.176.79.56]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vM1OI-00000006Shg-25o5 for linux-arm-kernel@lists.infradead.org; Thu, 20 Nov 2025 09:55:52 +0000 Received: from mail.maildlp.com (unknown [172.18.186.231]) by frasgout.his.huawei.com (SkyGuard) with ESMTPS id 4dBtxf2YMCzHnGhN; Thu, 20 Nov 2025 17:55:02 +0800 (CST) Received: from dubpeml100005.china.huawei.com (unknown [7.214.146.113]) by mail.maildlp.com (Postfix) with ESMTPS id D570214037D; Thu, 20 Nov 2025 17:55:36 +0800 (CST) Received: from localhost (10.203.177.15) by dubpeml100005.china.huawei.com (7.214.146.113) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.36; Thu, 20 Nov 2025 09:55:35 +0000 Date: Thu, 20 Nov 2025 09:55:33 +0000 From: Jonathan Cameron To: Conor Dooley CC: Randy Dunlap , Catalin Marinas , , , , , Dan Williams , "H . Peter Anvin" , Peter Zijlstra , "Andrew Morton" , Arnd Bergmann , "Drew Fustini" , Linus Walleij , Alexandre Belloni , Krzysztof Kozlowski , , Will Deacon , Davidlohr Bueso , , Yushan Wang , Lorenzo Pieralisi , "Mark Rutland" , Dave Hansen , Thomas Gleixner , Ingo Molnar , Borislav Petkov , , Andy Lutomirski , Dave Jiang Subject: Re: [PATCH v6 3/7] lib: Support ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION Message-ID: <20251120095533.00004b0e@huawei.com> In-Reply-To: <20251119-charging-gallon-bea196c3a547@spud> References: <20251117104800.2041329-1-Jonathan.Cameron@huawei.com> <20251117104800.2041329-4-Jonathan.Cameron@huawei.com> <3bf1793a-2ffd-4017-b4bf-dc63f3a2a7c8@infradead.org> <20251117-definite-uncounted-7cc07a377a71@spud> <20251118093041.00000c9e@huawei.com> <2241d985-0e35-41e5-93b1-1e8d4e7a84bf@infradead.org> <20251119094255.00000020@huawei.com> <20251119-charging-gallon-bea196c3a547@spud> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.42; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.203.177.15] X-ClientProxiedBy: lhrpeml500012.china.huawei.com (7.191.174.4) To dubpeml100005.china.huawei.com (7.214.146.113) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251120_015550_827741_B9362F96 X-CRM114-Status: GOOD ( 39.54 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, 19 Nov 2025 18:44:43 +0000 Conor Dooley wrote: > On Wed, Nov 19, 2025 at 09:42:55AM +0000, Jonathan Cameron wrote: > > On Tue, 18 Nov 2025 17:18:31 -0800 > > Randy Dunlap wrote: > > > > > On 11/18/25 1:30 AM, Jonathan Cameron wrote: > > > > On Tue, 18 Nov 2025 00:13:07 +0000 > > > > Conor Dooley wrote: > > > > > > > >> On Mon, Nov 17, 2025 at 10:51:11AM -0800, Randy Dunlap wrote: > > > >>> Hi, > > > >>> > > > >>> On 11/17/25 2:47 AM, Jonathan Cameron wrote: > > > >>>> diff --git a/lib/Kconfig b/lib/Kconfig > > > >>>> index e629449dd2a3..e11136d188ae 100644 > > > >>>> --- a/lib/Kconfig > > > >>>> +++ b/lib/Kconfig > > > >>>> @@ -542,6 +542,10 @@ config MEMREGION > > > >>>> config ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION > > > >>>> bool > > > >>>> > > > >>>> +config GENERIC_CPU_CACHE_MAINTENANCE > > > >>>> + bool > > > >>>> + select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION > > > >>>> + > > > >>>> config ARCH_HAS_MEMREMAP_COMPAT_ALIGN > > > >>>> bool > > > >>> > > > >>> Architectures and/or platforms select ARCH_HAS_*. > > > >>> > > > >>> With this change above, it becomes the only entry in > > > >>> lib/Kconfig that does "select ARCH_HAS_anytning". > > > >>> > > > >>> so I think this is wrong, back*wards. > > > >> > > > >> Maybe it is backwards, but I feel like this way is more logical. ARM64 > > > >> has memregion invalidation only because this generic approach is > > > >> enabled, so the arch selects what it needs to get the support. > > > > > > > > Exactly this. Catalin requested this form in response to an earlier > > > > version where arm64 Kconfig just had both selects for pretty much that > > > > reason. This is expected to be used on a subset of architectures. > > > > It is similar to things like GENERIC_ARCH_NUMA in this respect (though the > > > > arch_numa_init() etc in there are called only from other arch code > > > > so no ARCH_HAS_ symbols are associated with them). > > > > > > > >> Alternatively, something like > > > > > > > > I'm fine with this solution if Randy prefers it. > > > > > > I do much prefer this alternative. > > > > > > > Thanks for your help with this. > > > > > > Thanks for listening. > > > > Conor, > > > > Given it is your proposed solution, I'm guessing you'll either spin a patch > > on top or squash it into original. If you spin a patch for this. > > > > Acked-by: Jonathan Cameron > > New patch I think, since you say Catalin specifically asked for the > current setup. Whilst Catalin proposed the form used, the basis was about having two entrees for effectively the same thing in arm64/Kconfig and this still has the single entry property so should be fine. Jonathan > > > > > Thanks again! > > > > Jonathan > > > > > > > > > > > >> | diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > > > >> | index 5f7f63d24931..75b2507f7eb2 100644 > > > >> | --- a/arch/arm64/Kconfig > > > >> | +++ b/arch/arm64/Kconfig > > > >> | @@ -21,6 +21,7 @@ config ARM64 > > > >> | select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE > > > >> | select ARCH_HAS_CACHE_LINE_SIZE > > > >> | select ARCH_HAS_CC_PLATFORM > > > >> | + select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION > > > >> | select ARCH_HAS_CURRENT_STACK_POINTER > > > >> | select ARCH_HAS_DEBUG_VIRTUAL > > > >> | select ARCH_HAS_DEBUG_VM_PGTABLE > > > >> | @@ -146,7 +147,6 @@ config ARM64 > > > >> | select GENERIC_ARCH_TOPOLOGY > > > >> | select GENERIC_CLOCKEVENTS_BROADCAST > > > >> | select GENERIC_CPU_AUTOPROBE > > > >> | - select GENERIC_CPU_CACHE_MAINTENANCE > > > >> | select GENERIC_CPU_DEVICES > > > >> | select GENERIC_CPU_VULNERABILITIES > > > >> | select GENERIC_EARLY_IOREMAP > > > >> | diff --git a/lib/Kconfig b/lib/Kconfig > > > >> | index 09aec4a1e13f..ac223e627bc5 100644 > > > >> | --- a/lib/Kconfig > > > >> | +++ b/lib/Kconfig > > > >> | @@ -544,8 +544,9 @@ config ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION > > > >> | bool > > > >> | > > > >> | config GENERIC_CPU_CACHE_MAINTENANCE > > > >> | - bool > > > >> | - select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION > > > >> | + def_bool y > > > >> | + depends on ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION > > > >> | + depends on ARM64 > > > >> | > > > >> | config ARCH_HAS_MEMREMAP_COMPAT_ALIGN > > > >> | bool > > > >> implies (to me at least) that arm64 has memregion invalidation as an > > > >> architectural feature and that the GENERIC_CPU_CACHE_MAINTENANCE option > > > >> is a just common cross-arch code, like generic entry etc, rather than > > > >> being the option gating the drivers that provide the feature in the > > > >> first place. > > > >> > > > >> I didn't really care which way it went, and was gonna post something to > > > >> squash and avoid another revision, but I found the resultant Kconfig > > > >> setup to be make less sense to me than what came before. If the switched > > > >> around version is less likely to be problematic etc, then sure, but I > > > >> amn't convinced by switching it at a first glance. > > > > > > > > >