From patchwork Wed Jul 14 12:50:12 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geert Uytterhoeven X-Patchwork-Id: 477668 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 CD097C11F6F for ; Wed, 14 Jul 2021 12:50:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AE2BD613C5 for ; Wed, 14 Jul 2021 12:50:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239420AbhGNMxn (ORCPT ); Wed, 14 Jul 2021 08:53:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38464 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239399AbhGNMxl (ORCPT ); Wed, 14 Jul 2021 08:53:41 -0400 Received: from andre.telenet-ops.be (andre.telenet-ops.be [IPv6:2a02:1800:120:4::f00:15]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8CFDFC0613DE for ; Wed, 14 Jul 2021 05:50:49 -0700 (PDT) Received: from ramsan.of.borg ([IPv6:2a02:1810:ac12:ed10:39cc:190a:2775:cfe7]) by andre.telenet-ops.be with bizsmtp id V0qW2500F1ccfby010qWp0; Wed, 14 Jul 2021 14:50:47 +0200 Received: from rox.of.borg ([192.168.97.57]) by ramsan.of.borg with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1m3eLO-0018dN-8G; Wed, 14 Jul 2021 14:50:30 +0200 Received: from geert by rox.of.borg with local (Exim 4.93) (envelope-from ) id 1m3eLN-00AaDx-Nr; Wed, 14 Jul 2021 14:50:29 +0200 From: Geert Uytterhoeven To: Rob Herring , Russell King , Nicolas Pitre , Ard Biesheuvel , Linus Walleij , Catalin Marinas , Will Deacon , Nick Kossifidis , Paul Walmsley , Palmer Dabbelt , Albert Ou , Frank Rowand , Dave Young , Mike Rapoport Cc: Baoquan He , Vivek Goyal , Andrew Morton , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-riscv@lists.infradead.org, kexec@lists.infradead.org, linux-mm@kvack.org, linux-renesas-soc@vger.kernel.org, linux-kernel@vger.kernel.org, Geert Uytterhoeven Subject: [PATCH v4 02/10] memblock: Add variables for usable memory limitation Date: Wed, 14 Jul 2021 14:50:12 +0200 Message-Id: <04c4d231fb03a3810d72a45c8a5bc2272c5975f3.1626266516.git.geert+renesas@glider.be> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Add two global variables (cap_mem_addr and cap_mem_size) for storing a base address and size, describing a limited region in which memory may be considered available for use by the kernel. If enabled, memory outside of this range is not available for use. These variables can by filled by firmware-specific code, and used in calls to memblock_cap_memory_range() by architecture-specific code. An example user is the parser of the "linux,usable-memory-range" property in the DT "/chosen" node. Signed-off-by: Geert Uytterhoeven --- This is similar to how the initial ramdisk (phys_initrd_{start,size}) and ELF core headers (elfcorehdr_{addr,size})) are handled. Does there exist a suitable place in the common memblock code to call "memblock_cap_memory_range(cap_mem_addr, cap_mem_size)", or does this have to be done in architecture-specific code? v4: - New. --- include/linux/memblock.h | 6 ++++++ mm/memblock.c | 2 ++ 2 files changed, 8 insertions(+) diff --git a/include/linux/memblock.h b/include/linux/memblock.h index cbf46f56d1053b68..07e2474c4c3901e9 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -25,6 +25,12 @@ extern unsigned long max_pfn; */ extern unsigned long long max_possible_pfn; +/* + * limited region in which memory may be considered usable by the kernel + */ +extern phys_addr_t cap_mem_addr; +extern phys_addr_t cap_mem_size; + /** * enum memblock_flags - definition of memory region attributes * @MEMBLOCK_NONE: no special request diff --git a/mm/memblock.c b/mm/memblock.c index 0041ff62c584e7e1..66659f2b10ed40ff 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -101,6 +101,8 @@ unsigned long max_low_pfn; unsigned long min_low_pfn; unsigned long max_pfn; unsigned long long max_possible_pfn; +phys_addr_t cap_mem_addr; +phys_addr_t cap_mem_size; static struct memblock_region memblock_memory_init_regions[INIT_MEMBLOCK_REGIONS] __initdata_memblock; static struct memblock_region memblock_reserved_init_regions[INIT_MEMBLOCK_RESERVED_REGIONS] __initdata_memblock;