From patchwork Tue Jun 15 18:17:25 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geert Uytterhoeven X-Patchwork-Id: 461614 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, 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 228FFC48BDF for ; Tue, 15 Jun 2021 18:17:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E699E613B9 for ; Tue, 15 Jun 2021 18:17:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231168AbhFOSTv (ORCPT ); Tue, 15 Jun 2021 14:19:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35654 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230120AbhFOSTu (ORCPT ); Tue, 15 Jun 2021 14:19:50 -0400 Received: from albert.telenet-ops.be (albert.telenet-ops.be [IPv6:2a02:1800:110:4::f00:1a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EE99DC0617AF for ; Tue, 15 Jun 2021 11:17:45 -0700 (PDT) Received: from ramsan.of.borg ([IPv6:2a02:1810:ac12:ed20:bda0:7de0:767e:26f9]) by albert.telenet-ops.be with bizsmtp id HWHe2500a4N5gS306WHeeA; Tue, 15 Jun 2021 20:17:42 +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 1ltDd4-00HYOP-66; Tue, 15 Jun 2021 20:17:38 +0200 Received: from geert by rox.of.borg with local (Exim 4.93) (envelope-from ) id 1ltDd3-005qAG-NQ; Tue, 15 Jun 2021 20:17:37 +0200 From: Geert Uytterhoeven To: Rob Herring , Nick Kossifidis , Paul Walmsley , Palmer Dabbelt , Albert Ou , Frank Rowand , Catalin Marinas , Will Deacon Cc: devicetree@vger.kernel.org, linux-riscv@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Geert Uytterhoeven Subject: [PATCH 1/3] of: fdt: Add generic support for parsing elf core header properties Date: Tue, 15 Jun 2021 20:17:25 +0200 Message-Id: <8661d652968d050489852ccb50df5ad4cc048900.1623780059.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 There are two methods to specify the location of the elf core header: 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 handling, 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". Signed-off-by: Geert Uytterhoeven --- Documentation/devicetree/bindings/chosen.txt | 6 ++-- drivers/of/fdt.c | 37 ++++++++++++++++++-- 2 files changed, 37 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 a03d43f95495d8e1..f13db831c8028cce 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 @@ -909,6 +910,35 @@ static inline void early_init_dt_check_for_initrd(unsigned long node) } #endif /* CONFIG_BLK_DEV_INITRD */ +#ifdef CONFIG_CRASH_DUMP +/** + * 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; + + 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); +} +#else +static inline void early_init_dt_check_for_elfcorehdr(unsigned long node) +{ +} +#endif + #ifdef CONFIG_SERIAL_EARLYCON int __init early_init_dt_scan_chosen_stdout(void) @@ -1057,6 +1087,7 @@ 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); @@ -1201,14 +1232,14 @@ 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); }