[PATCH v12 1/9] x86: kdump: move CRASH_ALIGN to 2M

[Chen Zhou]

CONFIG_PHYSICAL_ALIGN can be selected from 2M to 16M and default
value is 2M, so move CRASH_ALIGN to 2M, with smaller value reservation
can have more chance to succeed.
And replace the hard-coded alignment with macro CRASH_ALIGN in function
reserve_crashkernel().

Suggested-by: Dave Young <dyoung@xxxxxxxxxx>
Signed-off-by: Chen Zhou <chenzhou10@xxxxxxxxxx>
---
 arch/x86/include/asm/kexec.h | 3 +++
 arch/x86/kernel/setup.c      | 5 +----
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h
index 6802c59e8252..83f200dd54a1 100644
--- a/arch/x86/include/asm/kexec.h
+++ b/arch/x86/include/asm/kexec.h
@@ -18,6 +18,9 @@
 
 # define KEXEC_CONTROL_CODE_MAX_SIZE	2048
 
+/* 2M alignment for crash kernel regions */
+#define CRASH_ALIGN		SZ_2M
+
 #ifndef __ASSEMBLY__
 
 #include <linux/string.h>
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 3511736fbc74..296294ad0dd8 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -402,9 +402,6 @@ static void __init memblock_x86_reserve_range_setup_data(void)
 
 #ifdef CONFIG_KEXEC_CORE
 
-/* 16M alignment for crash kernel regions */
-#define CRASH_ALIGN		SZ_16M
-
 /*
  * Keep the crash kernel below this limit.
  *
@@ -530,7 +527,7 @@ static void __init reserve_crashkernel(void)
 
 		start = memblock_find_in_range(crash_base,
 					       crash_base + crash_size,
-					       crash_size, 1 << 20);
+					       crash_size, CRASH_ALIGN);
 		if (start != crash_base) {
 			pr_info("crashkernel reservation failed - memory is in use.\n");
 			return;
-- 
2.20.1