From patchwork Wed Jul 14 12:50:14 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geert Uytterhoeven X-Patchwork-Id: 477665 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=unavailable 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 689AEC11F6D for ; Wed, 14 Jul 2021 12:51:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 461A2613B9 for ; Wed, 14 Jul 2021 12:51:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239415AbhGNMxr (ORCPT ); Wed, 14 Jul 2021 08:53:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38538 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239443AbhGNMxq (ORCPT ); Wed, 14 Jul 2021 08:53:46 -0400 Received: from xavier.telenet-ops.be (xavier.telenet-ops.be [IPv6:2a02:1800:120:4::f00:14]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 63EBDC0613DD for ; Wed, 14 Jul 2021 05:50:54 -0700 (PDT) Received: from ramsan.of.borg ([IPv6:2a02:1810:ac12:ed10:39cc:190a:2775:cfe7]) by xavier.telenet-ops.be with bizsmtp id V0qX250091ccfby010qX5Y; Wed, 14 Jul 2021 14:50:46 +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-0018dP-Vb; Wed, 14 Jul 2021 14:50:30 +0200 Received: from geert by rox.of.borg with local (Exim 4.93) (envelope-from ) id 1m3eLN-00AaEC-PF; 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 04/10] of: fdt: Add generic support for parsing usable memory range property Date: Wed, 14 Jul 2021 14:50:14 +0200 Message-Id: <4064ea598a10ea0a4b9043aa771bcea1a00efac3.1626266516.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 support for parsing the "linux,usable-memory-range" property in the "/chosen" node to the FDT core code. This can co-exist safely with the architecture-specific parsing, until the latter has been removed. Architecture-specific code still has to make sure the resulting memory range limitation is applied, if present. Signed-off-by: Geert Uytterhoeven --- About the change to chosen.txt: I have a similar change for schemas/chosen.yaml in dt-schema. v4: - New. --- Documentation/devicetree/bindings/chosen.txt | 6 ++--- drivers/of/fdt.c | 24 ++++++++++++++++++++ 2 files changed, 27 insertions(+), 3 deletions(-) diff --git a/Documentation/devicetree/bindings/chosen.txt b/Documentation/devicetree/bindings/chosen.txt index 5b0b94eb2d04e79d..1cc3aa10dcb10588 100644 --- a/Documentation/devicetree/bindings/chosen.txt +++ b/Documentation/devicetree/bindings/chosen.txt @@ -79,9 +79,9 @@ a different secondary CPU release mechanism) linux,usable-memory-range ------------------------- -This property (arm64 only) holds a base address and size, describing a -limited region in which memory may be considered available for use by -the kernel. Memory outside of this range is not available for use. +This property holds a base address and size, describing a limited region in +which memory may be considered available for use by the kernel. Memory outside +of this range is not available for use. This property describes a limitation: memory within this range is only valid when also described through another mechanism that the kernel diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index f797d52c5b492cb7..1b4dd5418b44b9fb 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -935,6 +935,29 @@ static void __init early_init_dt_check_for_elfcorehdr(unsigned long node) elfcorehdr_addr, elfcorehdr_size); } +/** + * early_init_dt_check_for_usable_mem_range - Decode usable memory range + * location from flat tree + * @node: reference to node containing usable memory range location ('chosen') + */ +static void __init early_init_dt_check_for_usable_mem_range(unsigned long node) +{ + const __be32 *prop; + int len; + + pr_debug("Looking for usable-memory-range property... "); + + prop = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len); + if (!prop || (len < (dt_root_addr_cells + dt_root_size_cells))) + return; + + cap_mem_addr = dt_mem_next_cell(dt_root_addr_cells, &prop); + cap_mem_size = dt_mem_next_cell(dt_root_size_cells, &prop); + + pr_debug("cap_mem_start=%pa cap_mem_size=%pa\n", &cap_mem_addr, + &cap_mem_size); +} + #ifdef CONFIG_SERIAL_EARLYCON int __init early_init_dt_scan_chosen_stdout(void) @@ -1083,6 +1106,7 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname, early_init_dt_check_for_initrd(node); early_init_dt_check_for_elfcorehdr(node); + early_init_dt_check_for_usable_mem_range(node); /* Retrieve command line */ p = of_get_flat_dt_prop(node, "bootargs", &l);