[PATCH v3 3/8] arm64: kdump: identify memory regions
AKASHI Takahiro
takahiro.akashi at linaro.org
Tue Sep 6 21:33:56 PDT 2016
The following regions need to be identified for later use:
a) memory regions which belong to the 1st kernel
b) usable memory reserved for crash dump kernel
We go through /proc/iomem to find out a) and b) which are marked
as "System RAM" and "Crash kernel", respectively.
Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
---
kexec/arch/arm64/Makefile | 2 +
kexec/arch/arm64/crashdump-arm64.c | 100 ++++++++++++++++++++++++++++++++++++-
kexec/arch/arm64/crashdump-arm64.h | 14 +++++-
kexec/arch/arm64/iomem.h | 1 +
4 files changed, 114 insertions(+), 3 deletions(-)
diff --git a/kexec/arch/arm64/Makefile b/kexec/arch/arm64/Makefile
index 37414dc..c2535c6 100644
--- a/kexec/arch/arm64/Makefile
+++ b/kexec/arch/arm64/Makefile
@@ -5,6 +5,8 @@ arm64_FS2DT_INCLUDE += -include $(srcdir)/kexec/arch/arm64/kexec-arm64.h \
arm64_DT_OPS += kexec/dt-ops.c
+arm64_MEM_REGIONS = kexec/mem_regions.c
+
arm64_CPPFLAGS += -I $(srcdir)/kexec/
arm64_KEXEC_SRCS += \
diff --git a/kexec/arch/arm64/crashdump-arm64.c b/kexec/arch/arm64/crashdump-arm64.c
index d2272c8..dcaca43 100644
--- a/kexec/arch/arm64/crashdump-arm64.c
+++ b/kexec/arch/arm64/crashdump-arm64.c
@@ -1,5 +1,13 @@
/*
* ARM64 crashdump.
+ * partly derived from arm implementation
+ *
+ * Copyright (c) 2014-2016 Linaro Limited
+ * Author: AKASHI Takahiro <takahiro.akashi at linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
*/
#define _GNU_SOURCE
@@ -10,12 +18,102 @@
#include "kexec.h"
#include "crashdump.h"
#include "crashdump-arm64.h"
+#include "iomem.h"
#include "kexec-arm64.h"
#include "kexec-elf.h"
+#include "mem_regions.h"
-struct memory_ranges usablemem_rgns = {};
+/* memory ranges on crashed kernel */
+static struct memory_range crash_memory_ranges[CRASH_MAX_MEMORY_RANGES];
+static struct memory_ranges crash_memory_rgns = {
+ .size = 0,
+ .max_size = CRASH_MAX_MEMORY_RANGES,
+ .ranges = crash_memory_ranges,
+};
+
+/* memory range reserved for crashkernel */
+struct memory_range crash_reserved_mem;
+struct memory_ranges usablemem_rgns = {
+ .size = 0,
+ .max_size = 1,
+ .ranges = &crash_reserved_mem,
+};
+
+/*
+ * iomem_range_callback() - callback called for each iomem region
+ * @data: not used
+ * @nr: not used
+ * @str: name of the memory region
+ * @base: start address of the memory region
+ * @length: size of the memory region
+ *
+ * This function is called once for each memory region found in /proc/iomem.
+ * It locates system RAM and crashkernel reserved memory and places these to
+ * variables, respectively, crash_memory_ranges and crash_reserved_mem.
+ */
+
+static int iomem_range_callback(void *UNUSED(data), int UNUSED(nr),
+ char *str, unsigned long long base,
+ unsigned long long length)
+{
+ if (strncmp(str, CRASH_KERNEL, strlen(CRASH_KERNEL)) == 0)
+ return mem_regions_add(&usablemem_rgns,
+ base, length, RANGE_RAM);
+ else if (strncmp(str, SYSTEM_RAM, strlen(SYSTEM_RAM)) == 0)
+ return mem_regions_add(&crash_memory_rgns,
+ base, length, RANGE_RAM);
+
+ return 0;
+}
int is_crashkernel_mem_reserved(void)
{
+ if (!crash_reserved_mem.end)
+ kexec_iomem_for_each_line(NULL, iomem_range_callback, NULL);
+
+ return crash_reserved_mem.start != crash_reserved_mem.end;
+}
+
+/*
+ * crash_get_memory_ranges() - read system physical memory
+ *
+ * Function reads through system physical memory and stores found memory
+ * regions in crash_memory_ranges.
+ * Regions are sorted in ascending order.
+ *
+ * Returns 0 in case of success and -1 otherwise (errno is set).
+ */
+static int crash_get_memory_ranges(void)
+{
+ /*
+ * First read all memory regions that can be considered as
+ * system memory including the crash area.
+ */
+ if (!usablemem_rgns.size)
+ kexec_iomem_for_each_line(NULL, iomem_range_callback, NULL);
+
+ /* allow only a single region for crash dump kernel */
+ if (usablemem_rgns.size != 1) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ dbgprint_mem_range("Reserved memory range", &crash_reserved_mem, 1);
+
+ if (mem_regions_exclude(&crash_memory_rgns, &crash_reserved_mem)) {
+ fprintf(stderr,
+ "Error: Number of crash memory ranges excedeed the max limit\n");
+ errno = ENOMEM;
+ return -1;
+ }
+
+ /*
+ * Make sure that the memory regions are sorted.
+ */
+ mem_regions_sort(&crash_memory_rgns);
+
+ dbgprint_mem_range("Coredump memory ranges",
+ crash_memory_rgns.ranges, crash_memory_rgns.size);
+
return 0;
}
diff --git a/kexec/arch/arm64/crashdump-arm64.h b/kexec/arch/arm64/crashdump-arm64.h
index f33c7a2..07a0ed0 100644
--- a/kexec/arch/arm64/crashdump-arm64.h
+++ b/kexec/arch/arm64/crashdump-arm64.h
@@ -1,12 +1,22 @@
/*
* ARM64 crashdump.
+ *
+ * Copyright (c) 2014-2016 Linaro Limited
+ * Author: AKASHI Takahiro <takahiro.akashi at linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
*/
-#if !defined(CRASHDUMP_ARM64_H)
+#ifndef CRASHDUMP_ARM64_H
#define CRASHDUMP_ARM64_H
#include "kexec.h"
+#define CRASH_MAX_MEMORY_RANGES 32
+
extern struct memory_ranges usablemem_rgns;
+extern struct memory_range crash_reserved_mem;
-#endif
+#endif /* CRASHDUMP_ARM64_H */
diff --git a/kexec/arch/arm64/iomem.h b/kexec/arch/arm64/iomem.h
index 7fd66eb..20cda87 100644
--- a/kexec/arch/arm64/iomem.h
+++ b/kexec/arch/arm64/iomem.h
@@ -2,6 +2,7 @@
#define IOMEM_H
#define SYSTEM_RAM "System RAM\n"
+#define CRASH_KERNEL "Crash kernel\n"
#define IOMEM_RESERVED "reserved\n"
#endif
--
2.9.0
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