From patchwork Wed Jul 14 12:50:13 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geert Uytterhoeven X-Patchwork-Id: 12376861 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 90F09C11F73 for ; Wed, 14 Jul 2021 12:50:55 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 37046613C3 for ; Wed, 14 Jul 2021 12:50:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 37046613C3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=glider.be Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 14C5A8D0002; Wed, 14 Jul 2021 08:50:51 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 0FC5E6B0092; Wed, 14 Jul 2021 08:50:51 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E92808D0002; Wed, 14 Jul 2021 08:50:50 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0189.hostedemail.com [216.40.44.189]) by kanga.kvack.org (Postfix) with ESMTP id C09BF6B008C for ; Wed, 14 Jul 2021 08:50:50 -0400 (EDT) Received: from smtpin24.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id BA5948027FCF for ; Wed, 14 Jul 2021 12:50:49 +0000 (UTC) X-FDA: 78361177818.24.1C78654 Received: from andre.telenet-ops.be (andre.telenet-ops.be [195.130.132.53]) by imf05.hostedemail.com (Postfix) with ESMTP id 4DE32500AAB4 for ; Wed, 14 Jul 2021 12:50:48 +0000 (UTC) Received: from ramsan.of.borg ([IPv6:2a02:1810:ac12:ed10:39cc:190a:2775:cfe7]) by andre.telenet-ops.be with bizsmtp id V0qW2500C1ccfby010qWoz; 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-0018dO-3E; Wed, 14 Jul 2021 14:50:30 +0200 Received: from geert by rox.of.borg with local (Exim 4.93) (envelope-from ) id 1m3eLN-00AaE5-OX; 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 03/10] of: fdt: Add generic support for parsing elf core headers property Date: Wed, 14 Jul 2021 14:50:13 +0200 Message-Id: <24d93c713f6faeaee6105f57c3d94ac17f12405f.1626266516.git.geert+renesas@glider.be> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Authentication-Results: imf05.hostedemail.com; dkim=none; spf=none (imf05.hostedemail.com: domain of geert@linux-m68k.org has no SPF policy when checking 195.130.132.53) smtp.mailfrom=geert@linux-m68k.org; dmarc=none X-Stat-Signature: bfefhtp69uzw4ardme3m4cprixkgdo1j X-Rspamd-Queue-Id: 4DE32500AAB4 X-Rspamd-Server: rspam01 X-HE-Tag: 1626267048-535384 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: There are two methods to specify the location of the elf core headers: using the "elfcorehdr=" kernel parameter, as handled by generic code in kernel/crash_dump.c, or using the "linux,elfcorehdr" property under the "/chosen" node in the Device Tree, as handled by architecture-specific code in arch/arm64/mm/init.c. Extend support for "linux,elfcorehdr" to all platforms supporting DT by adding platform-agnostic handling for parsing this property to the FDT core code. This can co-exist safely with the architecture-specific parsing, until the latter has been removed. This requires moving the call to of_scan_flat_dt() up, as the code scanning the "/chosen" node now needs to be aware of the values of "#address-cells" and "#size-cells". Architecture-specific code still has to reserve the memory used by the elf core headers, 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: - Use IS_ENABLED() instead of #ifdef, - Clarify what architecture-specific code is still responsible for. --- Documentation/devicetree/bindings/chosen.txt | 6 ++-- drivers/of/fdt.c | 34 ++++++++++++++++++-- 2 files changed, 34 insertions(+), 6 deletions(-) diff --git a/Documentation/devicetree/bindings/chosen.txt b/Documentation/devicetree/bindings/chosen.txt index 45e79172a646c537..5b0b94eb2d04e79d 100644 --- a/Documentation/devicetree/bindings/chosen.txt +++ b/Documentation/devicetree/bindings/chosen.txt @@ -106,9 +106,9 @@ respectively, of the root node. linux,elfcorehdr ---------------- -This property (currently used only on arm64) holds the memory range, -the address and the size, of the elf core header which mainly describes -the panicked kernel's memory layout as PT_LOAD segments of elf format. +This property holds the memory range, the address and the size, of the elf +core header which mainly describes the panicked kernel's memory layout as +PT_LOAD segments of elf format. e.g. / { diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 344f16bb04ccf081..f797d52c5b492cb7 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -8,6 +8,7 @@ #define pr_fmt(fmt) "OF: fdt: " fmt +#include #include #include #include @@ -908,6 +909,32 @@ static inline void early_init_dt_check_for_initrd(unsigned long node) } #endif /* CONFIG_BLK_DEV_INITRD */ +/** + * early_init_dt_check_for_elfcorehdr - Decode elfcorehdr location from flat + * tree + * @node: reference to node containing elfcorehdr location ('chosen') + */ +static void __init early_init_dt_check_for_elfcorehdr(unsigned long node) +{ + const __be32 *prop; + int len; + + if (!IS_ENABLED(CONFIG_CRASH_DUMP)) + return; + + pr_debug("Looking for elfcorehdr property... "); + + prop = of_get_flat_dt_prop(node, "linux,elfcorehdr", &len); + if (!prop || (len < (dt_root_addr_cells + dt_root_size_cells))) + return; + + elfcorehdr_addr = dt_mem_next_cell(dt_root_addr_cells, &prop); + elfcorehdr_size = dt_mem_next_cell(dt_root_size_cells, &prop); + + pr_debug("elfcorehdr_start=0x%llx elfcorehdr_size=0x%llx\n", + elfcorehdr_addr, elfcorehdr_size); +} + #ifdef CONFIG_SERIAL_EARLYCON int __init early_init_dt_scan_chosen_stdout(void) @@ -1055,6 +1082,7 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname, return 0; early_init_dt_check_for_initrd(node); + early_init_dt_check_for_elfcorehdr(node); /* Retrieve command line */ p = of_get_flat_dt_prop(node, "bootargs", &l); @@ -1199,14 +1227,14 @@ void __init early_init_dt_scan_nodes(void) { int rc = 0; + /* Initialize {size,address}-cells info */ + of_scan_flat_dt(early_init_dt_scan_root, NULL); + /* Retrieve various information from the /chosen node */ rc = of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line); if (!rc) pr_warn("No chosen node found, continuing without\n"); - /* Initialize {size,address}-cells info */ - of_scan_flat_dt(early_init_dt_scan_root, NULL); - /* Setup memory, calling early_init_dt_add_memory_arch */ of_scan_flat_dt(early_init_dt_scan_memory, NULL); }