Hi Andi,
Andi Kleen wrote:
On Fri, Apr 15, 2005 at 11:43:55AM +0530, Hariprasad Nellitheertha wrote:
Hi Andi,
In order to port kdump to x86_64, we need to have the
memmap= kernel command line option available. This is so
that the dump-capture kernel can be booted with a custom
memory map.
The attached patch adds the memmap= functionality to the
x86_64 kernel. It is against 2.6.12-rc2-mm3. I have done
some amount of testing and it is working fine.
Could you kindly review this patch and let me know your
thoughts on it.
You should add a __setup somewhere, otherwise the kernel
will complain about unknown arguments or generate a memmap
variable in inits environment.
The memmap= option does not introduce any new variables that
we would need at a later point of time. Its very similar in
the way it handles the maps to the "mem=" option. Hence I
have not added the __setup in the attached patch.
Comma parsing would be nice.
I have introduced comma parsing. The patch for doing the
same in i386 follows in a separate patch.
Please review and let me know your comments.
Regards, Hari
This patch adds the 'memmap=' kernel command line option for the
x86_64 kernel.
Signed-off-by: Hariprasad Nellitheertha <[email protected]>
---
linux-2.6.12-rc2-hari/Documentation/kernel-parameters.txt | 2
linux-2.6.12-rc2-hari/arch/x86_64/kernel/e820.c | 32 ++++++++++++++
linux-2.6.12-rc2-hari/arch/x86_64/kernel/setup.c | 3 +
linux-2.6.12-rc2-hari/include/asm-x86_64/e820.h | 2
4 files changed, 38 insertions(+), 1 deletion(-)
diff -puN arch/x86_64/kernel/e820.c~x8664-memmap-command-line-option arch/x86_64/kernel/e820.c
--- linux-2.6.12-rc2/arch/x86_64/kernel/e820.c~x8664-memmap-command-line-option 2005-04-15 10:15:04.000000000 +0530
+++ linux-2.6.12-rc2-hari/arch/x86_64/kernel/e820.c 2005-04-27 16:27:45.000000000 +0530
@@ -513,6 +513,38 @@ void __init parse_memopt(char *p, char *
end_user_pfn >>= PAGE_SHIFT;
}
+void __init parse_memmapopt(char *p, char **from)
+{
+ do {
+ if (!memcmp(p, "exactmap", 8)) {
+ p += 8;
+ e820.nr_map = 0;
+ } else {
+ unsigned long long start_at, mem_size;
+
+ mem_size = memparse(p, from);
+ p = *from;
+ if (*p == '@') {
+ start_at = memparse(p+1, from);
+ add_memory_region(start_at, mem_size, E820_RAM);
+ } else if (*p == '#') {
+ start_at = memparse(p+1, from);
+ add_memory_region(start_at, mem_size, E820_ACPI);
+ } else if (*p == '$') {
+ start_at = memparse(p+1, from);
+ add_memory_region(start_at, mem_size, E820_RESERVED);
+ } else {
+ end_user_pfn = (mem_size >> PAGE_SHIFT);
+ }
+ p = *from;
+ }
+ if (*p != ',')
+ break;
+ else
+ p += 1;
+ } while(1);
+}
+
unsigned long pci_mem_start = 0xaeedbabe;
/*
diff -puN arch/x86_64/kernel/setup.c~x8664-memmap-command-line-option arch/x86_64/kernel/setup.c
--- linux-2.6.12-rc2/arch/x86_64/kernel/setup.c~x8664-memmap-command-line-option 2005-04-15 10:15:04.000000000 +0530
+++ linux-2.6.12-rc2-hari/arch/x86_64/kernel/setup.c 2005-04-15 10:15:04.000000000 +0530
@@ -349,6 +349,9 @@ static __init void parse_cmdline_early (
if (!memcmp(from, "mem=", 4))
parse_memopt(from+4, &from);
+ if (!memcmp(from, "memmap=", 7))
+ parse_memmapopt(from+7, &from);
+
#ifdef CONFIG_DISCONTIGMEM
if (!memcmp(from, "numa=", 5))
numa_setup(from+5);
diff -puN include/asm-x86_64/e820.h~x8664-memmap-command-line-option include/asm-x86_64/e820.h
--- linux-2.6.12-rc2/include/asm-x86_64/e820.h~x8664-memmap-command-line-option 2005-04-15 10:15:04.000000000 +0530
+++ linux-2.6.12-rc2-hari/include/asm-x86_64/e820.h 2005-04-15 10:15:04.000000000 +0530
@@ -54,6 +54,8 @@ extern void e820_setup_gap(void);
extern void __init parse_memopt(char *p, char **end);
+extern void __init parse_memmapopt(char *p, char **end);
+
extern struct e820map e820;
#endif/*!__ASSEMBLY__*/
diff -puN Documentation/kernel-parameters.txt~x8664-memmap-command-line-option Documentation/kernel-parameters.txt
--- linux-2.6.12-rc2/Documentation/kernel-parameters.txt~x8664-memmap-command-line-option 2005-04-15 10:19:37.000000000 +0530
+++ linux-2.6.12-rc2-hari/Documentation/kernel-parameters.txt 2005-04-15 10:19:56.000000000 +0530
@@ -794,7 +794,7 @@ running once the system is up.
mem=nopentium [BUGS=IA-32] Disable usage of 4MB pages for kernel
memory.
- memmap=exactmap [KNL,IA-32] Enable setting of an exact
+ memmap=exactmap [KNL,IA-32,X86-64] Enable setting of an exact
E820 memory map, as specified by the user.
Such memmap=exactmap lines can be constructed based on
BIOS output or other requirements. See the memmap=nn@ss
_
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