[PATCH] x86, setup: Correct comment in reserve_crashkernel

[Zhang Yanfei <zhangyanfei.yes@gmail.com>]

From: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>

One comment in reserve_crashkernel is out of date and incorrect.
So fix it.

Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
---
 arch/x86/kernel/setup.c |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 56f7fcf..eba0d78 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -590,7 +590,12 @@ static void __init reserve_crashkernel(void)
 	/* 0 means: find the address automatically */
 	if (crash_base <= 0) {
 		/*
-		 *  kexec want bzImage is below CRASH_KERNEL_ADDR_MAX
+		 *  For x86_64, when crashkernel=X,high is not passed, kexec
+		 *  wants bzImage is below CRASH_KERNEL_ADDR_LOW_MAX.
+		 *  For x86_32, crashkernel=X,high is not supported by defining
+		 *  CRASH_KERNEL_ADDR_HIGH_MAX and CRASH_KERNEL_ADDR_LOW_MAX
+		 *  with the same limit and kexec always wants bzImage is below
+		 *  this limit due to mapping restrictions.
 		 */
 		crash_base = memblock_find_in_range(alignment,
 					high ? CRASH_KERNEL_ADDR_HIGH_MAX :
-- 
1.7.1