From: Huacai Chen <chenhc@xxxxxxxxxx>
kexec-tools use mem=X@Y to pass usable memories to capture kernel, but
in commit a94e4f24ec836c8984f83959 ("MIPS: init: Drop boot_mem_map") all
BIOS passed memories are removed by early_parse_mem(). I think this is
reasonable for a normal kernel but not for a capture kernel, because a
capture kernel should be able to see all old memories, even though it is
not supposed to use them.
Fixes: a94e4f24ec836c8984f83959 ("MIPS: init: Drop boot_mem_map")
Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxx>
Signed-off-by: Youling Tang <tangyouling@xxxxxxxxxxx>
---
v2:
- Determine whether it is a capture kernel by judging whether there
is an "elfcorehdr" parameter in the cmdline.
arch/mips/kernel/setup.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index 9338520..1bc8a9cc 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -352,8 +352,13 @@ static int __init early_parse_mem(char *p)
*/
if (usermem == 0) {
usermem = 1;
- memblock_remove(memblock_start_of_DRAM(),
- memblock_end_of_DRAM() - memblock_start_of_DRAM());
+ /*
+ * During the kdump operation, the old memory should be
+ * visible to the capture kernel.
+ */
+ if (!strstr(boot_command_line, "elfcorehdr"))
+ memblock_remove(memblock_start_of_DRAM(),
+ memblock_end_of_DRAM() - memblock_start_of_DRAM());
}
start = 0;
size = memparse(p, &p);
--
2.1.0
