From: Geert Uytterhoeven <geert+renesas@glider.be>
To: Rob Herring <robh+dt@kernel.org>,
Nick Kossifidis <mick@ics.forth.gr>,
Paul Walmsley <paul.walmsley@sifive.com>,
Palmer Dabbelt <palmer@dabbelt.com>,
Albert Ou <aou@eecs.berkeley.edu>,
Frank Rowand <frowand.list@gmail.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>
Cc: devicetree@vger.kernel.org, linux-riscv@lists.infradead.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org,
Geert Uytterhoeven <geert+renesas@glider.be>
Subject: [PATCH 1/3] of: fdt: Add generic support for parsing elf core header properties
Date: Tue, 15 Jun 2021 20:17:25 +0200 [thread overview]
Message-ID: <8661d652968d050489852ccb50df5ad4cc048900.1623780059.git.geert+renesas@glider.be> (raw)
In-Reply-To: <cover.1623780059.git.geert+renesas@glider.be>
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 <geert+renesas@glider.be>
---
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 <linux/crash_dump.h>
#include <linux/crc32.h>
#include <linux/kernel.h>
#include <linux/initrd.h>
@@ -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);
}
--
2.25.1
next prev parent reply other threads:[~2021-06-15 18:17 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-15 18:17 [PATCH 0/3] Add generic-support for linux,elfcorehdr and fix riscv Geert Uytterhoeven
2021-06-15 18:17 ` Geert Uytterhoeven [this message]
2021-06-15 19:54 ` [PATCH 1/3] of: fdt: Add generic support for parsing elf core header properties Rob Herring
2021-06-15 23:28 ` Nick Kossifidis
2021-06-16 7:58 ` Geert Uytterhoeven
2021-06-15 18:17 ` [PATCH 2/3] riscv: Remove non-standard linux,elfcorehdr handling Geert Uytterhoeven
2021-06-15 18:40 ` Nick Kossifidis
2021-06-15 19:54 ` Rob Herring
2021-06-15 23:19 ` Nick Kossifidis
2021-06-16 7:56 ` Geert Uytterhoeven
2021-06-16 10:43 ` Nick Kossifidis
2021-06-16 14:47 ` Rob Herring
2021-07-01 2:52 ` Palmer Dabbelt
2021-07-02 15:56 ` Nick Kossifidis
2021-06-15 18:17 ` [PATCH 3/3] arm64: kdump: Remove custom linux,elfcorehdr parsing Geert Uytterhoeven
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