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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 968FFC4361B for ; Wed, 9 Dec 2020 02:37:15 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B891F2389E for ; Wed, 9 Dec 2020 02:37:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B891F2389E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 20D186B008A; Tue, 8 Dec 2020 21:37:14 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 197966B008C; Tue, 8 Dec 2020 21:37:14 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 05EB96B0092; Tue, 8 Dec 2020 21:37:13 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0179.hostedemail.com [216.40.44.179]) by kanga.kvack.org (Postfix) with ESMTP id E19136B008A for ; Tue, 8 Dec 2020 21:37:13 -0500 (EST) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id B26913628 for ; Wed, 9 Dec 2020 02:37:13 +0000 (UTC) X-FDA: 77572181946.17.bath64_2512d55273ec Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin17.hostedemail.com (Postfix) with ESMTP id 94D1D180D0180 for ; Wed, 9 Dec 2020 02:37:13 +0000 (UTC) X-HE-Tag: bath64_2512d55273ec X-Filterd-Recvd-Size: 5213 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf40.hostedemail.com (Postfix) with ESMTP for ; Wed, 9 Dec 2020 02:37:12 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 28D0D1042; Tue, 8 Dec 2020 18:37:12 -0800 (PST) Received: from [192.168.0.130] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 264253F66B; Tue, 8 Dec 2020 18:37:07 -0800 (PST) Subject: Re: [PATCH 3/3] s390/mm: Define arch_get_mappable_range() To: Heiko Carstens Cc: linux-mm@kvack.org, akpm@linux-foundation.org, david@redhat.com, catalin.marinas@arm.com, linux-arm-kernel@lists.infradead.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, Vasily Gorbik , Will Deacon , Ard Biesheuvel , Mark Rutland References: <1607400978-31595-1-git-send-email-anshuman.khandual@arm.com> <1607400978-31595-4-git-send-email-anshuman.khandual@arm.com> <20201208152709.GA26979@osiris> From: Anshuman Khandual Message-ID: <7484e153-6c77-8325-6195-621fe144011e@arm.com> Date: Wed, 9 Dec 2020 08:07:04 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20201208152709.GA26979@osiris> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 12/8/20 8:57 PM, Heiko Carstens wrote: > On Tue, Dec 08, 2020 at 09:46:18AM +0530, Anshuman Khandual wrote: >> This overrides arch_get_mappabble_range() on s390 platform which will be >> used with recently added generic framework. It drops a redundant similar >> check in vmem_add_mapping() while compensating __segment_load() with a new >> address range check to preserve the existing functionality. It also adds a >> VM_BUG_ON() check that would ensure that memhp_range_allowed() has already >> been called on the hotplug path. >> >> Cc: Heiko Carstens >> Cc: Vasily Gorbik >> Cc: David Hildenbrand >> Cc: linux-s390@vger.kernel.org >> Cc: linux-kernel@vger.kernel.org >> Signed-off-by: Anshuman Khandual >> --- >> arch/s390/mm/extmem.c | 5 +++++ >> arch/s390/mm/init.c | 10 ++++++++++ >> arch/s390/mm/vmem.c | 4 ---- >> 3 files changed, 15 insertions(+), 4 deletions(-) >> >> diff --git a/arch/s390/mm/extmem.c b/arch/s390/mm/extmem.c >> index 5060956b8e7d..cc055a78f7b6 100644 >> --- a/arch/s390/mm/extmem.c >> +++ b/arch/s390/mm/extmem.c >> @@ -337,6 +337,11 @@ __segment_load (char *name, int do_nonshared, unsigned long *addr, unsigned long >> goto out_free_resource; >> } >> >> + if (seg->end + 1 > VMEM_MAX_PHYS || seg->end + 1 < seg->start_addr) { >> + rc = -ERANGE; >> + goto out_resource; >> + } >> + >> rc = vmem_add_mapping(seg->start_addr, seg->end - seg->start_addr + 1); >> if (rc) >> goto out_resource; >> diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c >> index 77767850d0d0..64937baabf93 100644 >> --- a/arch/s390/mm/init.c >> +++ b/arch/s390/mm/init.c >> @@ -278,6 +278,15 @@ device_initcall(s390_cma_mem_init); >> >> #endif /* CONFIG_CMA */ >> >> +struct range arch_get_mappable_range(void) >> +{ >> + struct range memhp_range; >> + >> + memhp_range.start = 0; >> + memhp_range.end = VMEM_MAX_PHYS; >> + return memhp_range; >> +} >> + >> int arch_add_memory(int nid, u64 start, u64 size, >> struct mhp_params *params) >> { >> @@ -291,6 +300,7 @@ int arch_add_memory(int nid, u64 start, u64 size, >> if (WARN_ON_ONCE(params->pgprot.pgprot != PAGE_KERNEL.pgprot)) >> return -EINVAL; >> >> + VM_BUG_ON(!memhp_range_allowed(start, size, 1)); >> rc = vmem_add_mapping(start, size); >> if (rc) >> return rc; >> diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c >> index b239f2ba93b0..749eab43aa93 100644 >> --- a/arch/s390/mm/vmem.c >> +++ b/arch/s390/mm/vmem.c >> @@ -536,10 +536,6 @@ int vmem_add_mapping(unsigned long start, unsigned long size) >> { >> int ret; >> >> - if (start + size > VMEM_MAX_PHYS || >> - start + size < start) >> - return -ERANGE; >> - > > Is there a reason why you added the memhp_range_allowed() check call > to arch_add_memory() instead of vmem_add_mapping()? If you would do As I had mentioned previously, memhp_range_allowed() is available with CONFIG_MEMORY_HOTPLUG but vmem_add_mapping() is always available. Hence there will be a build failure in vmem_add_mapping() for the range check memhp_range_allowed() without memory hotplug enabled. > that, then the extra code in __segment_load() wouldn't be > required. > Even though the error message from memhp_range_allowed() might be > highly confusing. Alternatively leaving __segment_load() and vmem_add_memory() unchanged will create three range checks i.e two memhp_range_allowed() and the existing VMEM_MAX_PHYS check in vmem_add_mapping() on all the hotplug paths, which is not optimal.