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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS 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 83BA9C4361B for ; Thu, 3 Dec 2020 23:36:16 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 01106223E8 for ; Thu, 3 Dec 2020 23:36:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 01106223E8 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 52DF26B0036; Thu, 3 Dec 2020 18:36:15 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 4DDBF6B005C; Thu, 3 Dec 2020 18:36:15 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3F28E8D0001; Thu, 3 Dec 2020 18:36:15 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0209.hostedemail.com [216.40.44.209]) by kanga.kvack.org (Postfix) with ESMTP id 270D76B0036 for ; Thu, 3 Dec 2020 18:36:15 -0500 (EST) Received: from smtpin30.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id DE1B0180AD80F for ; Thu, 3 Dec 2020 23:36:14 +0000 (UTC) X-FDA: 77553581868.30.heart77_0f182e8273bf Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin30.hostedemail.com (Postfix) with ESMTP id BB7B3180B3C83 for ; Thu, 3 Dec 2020 23:36:14 +0000 (UTC) X-HE-Tag: heart77_0f182e8273bf X-Filterd-Recvd-Size: 3949 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf23.hostedemail.com (Postfix) with ESMTP for ; Thu, 3 Dec 2020 23:36:14 +0000 (UTC) Date: Thu, 3 Dec 2020 15:36:10 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1607038573; bh=Pa4oRfRRHtvNG6DkXhfCABnpMt5dHNY/S5ZIo3xu0I8=; h=From:To:Cc:Subject:In-Reply-To:References:From; b=kuOijURD2S/LKZN7m2xU1Yqs8aTgSaE+8PAXCjOUF+k6SmWXgnBX1a127MGk9xsxD Zehgx/bS+bttrniAwVRGaqKRk/HeHmkpC5g5mw+66gde6sKC1WxOhrIrOWZsRz9QI2 m7IWOOo+Ox/qds8Kx515xXzlhgz0bQmTT4jC/P9M= From: Andrew Morton To: Mike Rapoport Cc: Alexander Viro , Andy Lutomirski , Arnd Bergmann , Borislav Petkov , Catalin Marinas , Christopher Lameter , Dan Williams , Dave Hansen , David Hildenbrand , Elena Reshetova , "H. Peter Anvin" , Ingo Molnar , James Bottomley , "Kirill A. Shutemov" , Matthew Wilcox , Mark Rutland , Mike Rapoport , Michael Kerrisk , Palmer Dabbelt , Paul Walmsley , Peter Zijlstra , Rick Edgecombe , Roman Gushchin , Shakeel Butt , Shuah Khan , Thomas Gleixner , Tycho Andersen , Will Deacon , linux-api@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-nvdimm@lists.01.org, linux-riscv@lists.infradead.org, x86@kernel.org Subject: Re: [PATCH v14 04/10] set_memory: allow querying whether set_direct_map_*() is actually enabled Message-Id: <20201203153610.724f40f26ca1620247bc6b09@linux-foundation.org> In-Reply-To: <20201203062949.5484-5-rppt@kernel.org> References: <20201203062949.5484-1-rppt@kernel.org> <20201203062949.5484-5-rppt@kernel.org> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII 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 Thu, 3 Dec 2020 08:29:43 +0200 Mike Rapoport wrote: > From: Mike Rapoport > > On arm64, set_direct_map_*() functions may return 0 without actually > changing the linear map. This behaviour can be controlled using kernel > parameters, so we need a way to determine at runtime whether calls to > set_direct_map_invalid_noflush() and set_direct_map_default_noflush() have > any effect. > > Extend set_memory API with can_set_direct_map() function that allows > checking if calling set_direct_map_*() will actually change the page table, > replace several occurrences of open coded checks in arm64 with the new > function and provide a generic stub for architectures that always modify > page tables upon calls to set_direct_map APIs. > > ... > > --- a/arch/arm64/mm/mmu.c > +++ b/arch/arm64/mm/mmu.c > @@ -22,6 +22,7 @@ > #include > #include > #include > +#include > > #include > #include > @@ -477,7 +478,7 @@ static void __init map_mem(pgd_t *pgdp) > int flags = 0; > u64 i; > > - if (rodata_full || debug_pagealloc_enabled()) > + if (can_set_direct_map()) > flags = NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS; Changes in -next turned this into if (can_set_direct_map() || crash_mem_map)