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 X-Spam-Level: X-Spam-Status: No, score=-7.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5166AC433E0 for ; Fri, 22 Jan 2021 10:47:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EE73D23358 for ; Fri, 22 Jan 2021 10:47:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726654AbhAVKrB (ORCPT ); Fri, 22 Jan 2021 05:47:01 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:35063 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727325AbhAVKnz (ORCPT ); Fri, 22 Jan 2021 05:43:55 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1611312148; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=CpPJgVGF/OVOMNhuDicsfSWDqhWkOAiL/HDAWsmxHzI=; b=e/lqhIe93qIMdnZ8JXo6pZ+gJZjaXtd5kk2n4/v2rdFhW8JgTkyiGY8603Dpr8jM+Mj+Op DVTyS1TK8DjPBhcu91HGbuvkZCdt8E++vzojpcV0+EvL9+peMqwwxzsbzMwrd7fEvjyP7J xSbeHdJX53BHmyDs2UVFF/mnmvEViBc= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-476-mVR29gWrOjqxrQzPPbf4AA-1; Fri, 22 Jan 2021 05:42:24 -0500 X-MC-Unique: mVR29gWrOjqxrQzPPbf4AA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 98F011005504; Fri, 22 Jan 2021 10:42:21 +0000 (UTC) Received: from [10.36.114.142] (ovpn-114-142.ams2.redhat.com [10.36.114.142]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9BE396EF45; Fri, 22 Jan 2021 10:42:18 +0000 (UTC) Subject: Re: [PATCH V3 1/3] mm/memory_hotplug: Prevalidate the address range being added with platform To: Anshuman Khandual , linux-mm@kvack.org, akpm@linux-foundation.org, hca@linux.ibm.com, catalin.marinas@arm.com Cc: Oscar Salvador , Vasily Gorbik , Will Deacon , Ard Biesheuvel , Mark Rutland , linux-arm-kernel@lists.infradead.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org References: <1610975582-12646-1-git-send-email-anshuman.khandual@arm.com> <1610975582-12646-2-git-send-email-anshuman.khandual@arm.com> <9916f217-ec29-33ff-a260-7a26792d23a1@redhat.com> <897c31ba-d3bd-b694-8c87-82e784a60c51@arm.com> From: David Hildenbrand Organization: Red Hat GmbH Message-ID: <5e133a5e-41bb-9d6b-f76e-a96d3efe0f5e@redhat.com> Date: Fri, 22 Jan 2021 11:42:17 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.5.0 MIME-Version: 1.0 In-Reply-To: <897c31ba-d3bd-b694-8c87-82e784a60c51@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 22.01.21 11:41, Anshuman Khandual wrote: > > On 1/22/21 2:48 PM, David Hildenbrand wrote: >> >>> +/* >>> + * Platforms should define arch_get_mappable_range() that provides >>> + * maximum possible addressable physical memory range for which the >>> + * linear mapping could be created. The platform returned address >>> + * range must adhere to these following semantics. >>> + * >>> + * - range.start <= range.end >>> + * - Range includes both end points [range.start..range.end] >>> + * >>> + * There is also a fallback definition provided here, allowing the >>> + * entire possible physical address range in case any platform does >>> + * not define arch_get_mappable_range(). >>> + */ >>> +struct range __weak arch_get_mappable_range(void) >>> +{ >>> + struct range memhp_range = { >>> + .start = 0UL, >>> + .end = -1ULL, >>> + }; >>> + return memhp_range; >>> +} >>> + >>> +struct range memhp_get_pluggable_range(bool need_mapping) >>> +{ >>> + const u64 max_phys = (1ULL << (MAX_PHYSMEM_BITS + 1)) - 1; >> >> Sorry, thought about that line a bit more, and I think this is just >> wrong (took me longer to realize as it should). The old code used this >> calculation to print the limit only (in a wrong way), let's recap: >> >> Assume MAX_PHYSMEM_BITS=32 >> >> max_phys = (1ULL << (32 + 1)) - 1 = 0x1ffffffffull; >> >> Ehm, these are 33 bit. >> >> OTOH, old code checked for >> >> if (max_addr >> MAX_PHYSMEM_BITS) { >> >> Which makes sense, because >> >> 0x1ffffffffull >> 32 = 1 >> >> results in "true", meaning it's to big, while >> >> 0xffffffffull >> 32 = 0 >> >> correctly results in "false", meaning the address is fine. >> >> >> >> So, this should just be >> >> const u64 max_phys = 1ULL << MAX_PHYSMEM_BITS; >> >> (similarly as calculated in virito-mem code, or in kernel/resource.c) > > Should this be 1ULL << MAX_PHYSMEM_BITS - 1 instead ? Currently there are Yes, obviously, sorry, forgot the -1. -- Thanks, David / dhildenb 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 X-Spam-Level: X-Spam-Status: No, score=-5.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 69FD7C433DB for ; Fri, 22 Jan 2021 10:44:11 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id F37DA222B6 for ; Fri, 22 Jan 2021 10:44:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F37DA222B6 Authentication-Results: mail.kernel.org; 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Fri, 22 Jan 2021 05:42:24 -0500 X-MC-Unique: mVR29gWrOjqxrQzPPbf4AA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 98F011005504; Fri, 22 Jan 2021 10:42:21 +0000 (UTC) Received: from [10.36.114.142] (ovpn-114-142.ams2.redhat.com [10.36.114.142]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9BE396EF45; Fri, 22 Jan 2021 10:42:18 +0000 (UTC) Subject: Re: [PATCH V3 1/3] mm/memory_hotplug: Prevalidate the address range being added with platform To: Anshuman Khandual , linux-mm@kvack.org, akpm@linux-foundation.org, hca@linux.ibm.com, catalin.marinas@arm.com References: <1610975582-12646-1-git-send-email-anshuman.khandual@arm.com> <1610975582-12646-2-git-send-email-anshuman.khandual@arm.com> <9916f217-ec29-33ff-a260-7a26792d23a1@redhat.com> <897c31ba-d3bd-b694-8c87-82e784a60c51@arm.com> From: David Hildenbrand Organization: Red Hat GmbH Message-ID: <5e133a5e-41bb-9d6b-f76e-a96d3efe0f5e@redhat.com> Date: Fri, 22 Jan 2021 11:42:17 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.5.0 MIME-Version: 1.0 In-Reply-To: <897c31ba-d3bd-b694-8c87-82e784a60c51@arm.com> Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210122_054229_393674_24CC0585 X-CRM114-Status: GOOD ( 18.77 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , linux-s390@vger.kernel.org, Vasily Gorbik , linux-kernel@vger.kernel.org, Will Deacon , Ard Biesheuvel , linux-arm-kernel@lists.infradead.org, Oscar Salvador Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 22.01.21 11:41, Anshuman Khandual wrote: > > On 1/22/21 2:48 PM, David Hildenbrand wrote: >> >>> +/* >>> + * Platforms should define arch_get_mappable_range() that provides >>> + * maximum possible addressable physical memory range for which the >>> + * linear mapping could be created. The platform returned address >>> + * range must adhere to these following semantics. >>> + * >>> + * - range.start <= range.end >>> + * - Range includes both end points [range.start..range.end] >>> + * >>> + * There is also a fallback definition provided here, allowing the >>> + * entire possible physical address range in case any platform does >>> + * not define arch_get_mappable_range(). >>> + */ >>> +struct range __weak arch_get_mappable_range(void) >>> +{ >>> + struct range memhp_range = { >>> + .start = 0UL, >>> + .end = -1ULL, >>> + }; >>> + return memhp_range; >>> +} >>> + >>> +struct range memhp_get_pluggable_range(bool need_mapping) >>> +{ >>> + const u64 max_phys = (1ULL << (MAX_PHYSMEM_BITS + 1)) - 1; >> >> Sorry, thought about that line a bit more, and I think this is just >> wrong (took me longer to realize as it should). The old code used this >> calculation to print the limit only (in a wrong way), let's recap: >> >> Assume MAX_PHYSMEM_BITS=32 >> >> max_phys = (1ULL << (32 + 1)) - 1 = 0x1ffffffffull; >> >> Ehm, these are 33 bit. >> >> OTOH, old code checked for >> >> if (max_addr >> MAX_PHYSMEM_BITS) { >> >> Which makes sense, because >> >> 0x1ffffffffull >> 32 = 1 >> >> results in "true", meaning it's to big, while >> >> 0xffffffffull >> 32 = 0 >> >> correctly results in "false", meaning the address is fine. >> >> >> >> So, this should just be >> >> const u64 max_phys = 1ULL << MAX_PHYSMEM_BITS; >> >> (similarly as calculated in virito-mem code, or in kernel/resource.c) > > Should this be 1ULL << MAX_PHYSMEM_BITS - 1 instead ? Currently there are Yes, obviously, sorry, forgot the -1. -- Thanks, David / dhildenb _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel