From: Vivek Goyal <vgoyal@in.ibm.com>
This patch adds support for reserving 640k memory as backup region as
required by crashdump kernel for x86.
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/Documentation/kernel-parameters.txt | 5 +++++
25-akpm/arch/i386/kernel/setup.c | 26 ++++++++++++++++++++++++--
25-akpm/arch/i386/mm/discontig.c | 8 ++++++++
25-akpm/include/linux/crash_dump.h | 1 +
25-akpm/include/linux/kexec.h | 6 +++++-
25-akpm/kernel/crash_dump.c | 3 +++
25-akpm/kernel/kexec.c | 8 ++++++++
7 files changed, 54 insertions(+), 3 deletions(-)
diff -puN arch/i386/kernel/setup.c~crashdump-reserving-backup-region-for-kexec-based arch/i386/kernel/setup.c
--- 25/arch/i386/kernel/setup.c~crashdump-reserving-backup-region-for-kexec-based 2005-01-23 01:51:11.604628880 -0800
+++ 25-akpm/arch/i386/kernel/setup.c 2005-01-23 01:51:11.617626904 -0800
@@ -41,6 +41,7 @@
#include <linux/init.h>
#include <linux/edd.h>
#include <linux/kexec.h>
+#include <linux/crash_dump.h>
#include <video/edid.h>
#include <asm/apic.h>
#include <asm/e820.h>
@@ -51,7 +52,6 @@
#include <asm/io_apic.h>
#include <asm/ist.h>
#include <asm/io.h>
-#include <asm/crash_dump.h>
#include "setup_arch_pre.h"
#include <bios_ebda.h>
@@ -854,7 +854,20 @@ static void __init parse_cmdline_early (
}
}
#endif
-
+#ifdef CONFIG_CRASH_DUMP
+ /* crashbackup=size@addr specifies the location of backup
+ * region where, crashed kernel has stored some backup data.
+ */
+ else if (!memcmp(from, "crashbackup=", 12)) {
+ unsigned long size, base;
+ size = memparse(from+12, &from);
+ if (*from == '@') {
+ base = memparse(from+1, &from);
+ crashbackup_start = base;
+ crashbackup_end = base + size - 1;
+ }
+ }
+#endif
/*
* highmem=size forces highmem to be exactly 'size' bytes.
* This works even on boxes that have no highmem otherwise.
@@ -1161,6 +1174,14 @@ static unsigned long __init setup_memory
#ifdef CONFIG_KEXEC
if (crashk_res.start != crashk_res.end) {
reserve_bootmem(crashk_res.start, crashk_res.end - crashk_res.start + 1);
+
+#define CRASHDUMP_BACKUP_SZ 0xa0000
+ /* Steal 640K from top of reserved region for crash kernel */
+ if ((crashk_res.end - crashk_res.start) > CRASHDUMP_BACKUP_SZ) {
+ crashdumpk_res.end = crashk_res.end;
+ crashk_res.end = crashk_res.end - CRASHDUMP_BACKUP_SZ;
+ crashdumpk_res.start = crashk_res.end + 1;
+ }
}
#endif
return max_low_pfn;
@@ -1204,6 +1225,7 @@ legacy_init_iomem_resources(struct resou
request_resource(res, data_resource);
#ifdef CONFIG_KEXEC
request_resource(res, &crashk_res);
+ request_resource(res, &crashdumpk_res);
#endif
}
}
diff -puN arch/i386/mm/discontig.c~crashdump-reserving-backup-region-for-kexec-based arch/i386/mm/discontig.c
--- 25/arch/i386/mm/discontig.c~crashdump-reserving-backup-region-for-kexec-based 2005-01-23 01:51:11.605628728 -0800
+++ 25-akpm/arch/i386/mm/discontig.c 2005-01-23 01:51:11.618626752 -0800
@@ -29,6 +29,7 @@
#include <linux/highmem.h>
#include <linux/initrd.h>
#include <linux/nodemask.h>
+#include <linux/ioport.h>
#include <linux/kexec.h>
#include <asm/e820.h>
#include <asm/setup.h>
@@ -371,6 +372,13 @@ unsigned long __init setup_memory(void)
#ifdef CONFIG_KEXEC
if (crashk_res.start != crashk_res.end) {
reserve_bootmem(crashk_res.start, crashk_res.end - crashk_res.start + 1);
+#define CRASHDUMP_BACKUP_SZ 0xa0000
+ /* Steal 640K from top of reserved region for crash kernel */
+ if ((crashk_res.end - crashk_res.start) > CRASHDUMP_BACKUP_SZ) {
+ crashdumpk_res.end = crashk_res.end;
+ crashk_res.end = crashk_res.end - CRASHDUMP_BACKUP_SZ;
+ crashdumpk_res.start = crashk_res.end + 1;
+ }
}
#endif
return system_max_low_pfn;
diff -puN Documentation/kernel-parameters.txt~crashdump-reserving-backup-region-for-kexec-based Documentation/kernel-parameters.txt
--- 25/Documentation/kernel-parameters.txt~crashdump-reserving-backup-region-for-kexec-based 2005-01-23 01:51:11.607628424 -0800
+++ 25-akpm/Documentation/kernel-parameters.txt 2005-01-23 01:51:11.619626600 -0800
@@ -27,6 +27,7 @@ restrictions referred to are that the re
APM Advanced Power Management support is enabled.
AX25 Appropriate AX.25 support is enabled.
CD Appropriate CD support is enabled.
+ CRASHDUMP Crash Dump support is enabled.
DEVFS devfs support is enabled.
DRM Direct Rendering Management support is enabled.
EDD BIOS Enhanced Disk Drive Services (EDD) is enabled
@@ -345,6 +346,10 @@ running once the system is up.
[KNL] Reserve a chunk of physical memory to
hold a kernel to switch to with kexec on panic.
+ crashbackup=nn[KMG]@ss[KMG]
+ [KNL, CRASHDUMP] Specifies the location of crash data
+ backup region.
+
cs4232= [HW,OSS]
Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
diff -puN include/linux/crash_dump.h~crashdump-reserving-backup-region-for-kexec-based include/linux/crash_dump.h
--- 25/include/linux/crash_dump.h~crashdump-reserving-backup-region-for-kexec-based 2005-01-23 01:51:11.609628120 -0800
+++ 25-akpm/include/linux/crash_dump.h 2005-01-23 01:51:11.619626600 -0800
@@ -15,6 +15,7 @@ extern void elf_kcore_store_hdr(char *,
#ifdef CONFIG_CRASH_DUMP
extern struct file_operations proc_vmcore_operations;
extern struct proc_dir_entry *proc_vmcore;
+extern unsigned long crashbackup_start, crashbackup_end;
extern ssize_t copy_oldmem_page(unsigned long, char *, size_t, int);
extern void crash_create_proc_entry(void);
diff -puN include/linux/kexec.h~crashdump-reserving-backup-region-for-kexec-based include/linux/kexec.h
--- 25/include/linux/kexec.h~crashdump-reserving-backup-region-for-kexec-based 2005-01-23 01:51:11.610627968 -0800
+++ 25-akpm/include/linux/kexec.h 2005-01-23 01:51:11.620626448 -0800
@@ -79,7 +79,7 @@ struct kimage {
unsigned long control_page;
/* Flags to indicate special processing */
- int type : 1;
+ unsigned int type : 1;
#define KEXEC_TYPE_DEFAULT 0
#define KEXEC_TYPE_CRASH 1
};
@@ -122,6 +122,10 @@ extern struct kimage *kexec_crash_image;
*/
extern struct resource crashk_res;
+/* Location of backup region to hold the crashdump kernel data.
+ */
+extern struct resource crashdumpk_res;
+
#else /* !CONFIG_KEXEC */
static inline void crash_kexec(void) { }
#endif /* CONFIG_KEXEC */
diff -puN kernel/crash_dump.c~crashdump-reserving-backup-region-for-kexec-based kernel/crash_dump.c
--- 25/kernel/crash_dump.c~crashdump-reserving-backup-region-for-kexec-based 2005-01-23 01:51:11.612627664 -0800
+++ 25-akpm/kernel/crash_dump.c 2005-01-23 01:51:11.620626448 -0800
@@ -15,6 +15,9 @@
#include <asm/io.h>
#include <asm/uaccess.h>
+/* Location of crashdump backup region if there is one. */
+unsigned long crashbackup_start, crashbackup_end;
+
/*
* Copy a page from "oldmem". For this page, there is no pte mapped
* in the current kernel. We stitch up a pte, similar to kmap_atomic.
diff -puN kernel/kexec.c~crashdump-reserving-backup-region-for-kexec-based kernel/kexec.c
--- 25/kernel/kexec.c~crashdump-reserving-backup-region-for-kexec-based 2005-01-23 01:51:11.613627512 -0800
+++ 25-akpm/kernel/kexec.c 2005-01-23 01:51:11.621626296 -0800
@@ -32,6 +32,14 @@ struct resource crashk_res = {
.flags = IORESOURCE_BUSY | IORESOURCE_MEM
};
+/* Location of the backup area for the crash dump kernel */
+struct resource crashdumpk_res = {
+ .name = "Crash Dump Backup",
+ .start = 0,
+ .end = 0,
+ .flags = IORESOURCE_BUSY | IORESOURCE_MEM
+};
+
/*
* When kexec transitions to the new kernel there is a one-to-one
* mapping between physical and virtual addresses. On processors
_