From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0C22D274669; Wed, 19 Nov 2025 09:43:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.176.79.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763545384; cv=none; b=aTnnotPSRX/kXTrCa1jXNhMPU2QuhL4sCtbxiCTYWGU4CleXD+wqSiBF3an7lcIh8RmvORZUL5V0vZi4I5ODG1c7Fyr/Tl8xdRxfoHxAIv7B1d1KUQGsn2Z5GbHEx3esD7YrZr1sjPMtjCYW4WC40XlixQjRa+2y1ICZUfYcMLc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763545384; c=relaxed/simple; bh=6JCu47eH0Q+PpTjXFXPeuMA5TI1o0dypOyyry4RuPnU=; h=Date:From:To:CC:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=CnUnZzbkeFB//iTJ739TlyiYp5hFEbxaYqe08nGaDHNwZiEfxW9+blskD9QP07gV9D2c+EoiuLivkec/CeoxxP1PQx1kgn//k0NRLRhzpLScV0ZtBRAWY/ysgHtNBq6JGcqEPcDsuvDxelTsajP58HhHOYDxSQbgx5XTQOFHBsU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=185.176.79.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.18.186.216]) by frasgout.his.huawei.com (SkyGuard) with ESMTPS id 4dBGjL4B8yzJ46jN; Wed, 19 Nov 2025 17:42:14 +0800 (CST) Received: from dubpeml100005.china.huawei.com (unknown [7.214.146.113]) by mail.maildlp.com (Postfix) with ESMTPS id 3D0E91401DC; Wed, 19 Nov 2025 17:42:58 +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; Wed, 19 Nov 2025 09:42:56 +0000 Date: Wed, 19 Nov 2025 09:42:55 +0000 From: Jonathan Cameron To: Randy Dunlap CC: Conor Dooley , 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: <20251119094255.00000020@huawei.com> In-Reply-To: <2241d985-0e35-41e5-93b1-1e8d4e7a84bf@infradead.org> 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> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.42; x86_64-w64-mingw32) Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: lhrpeml500010.china.huawei.com (7.191.174.240) To dubpeml100005.china.huawei.com (7.214.146.113) 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 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. > >