[PATCH 2/4] x86/setup: Use parse_crashkernel_high_low() to simplify code

[Zhen Lei <thunder.leizhen@xxxxxxxxxx>]

Use parse_crashkernel_high_low() to bring the parsing of
"crashkernel=X,high" and the parsing of "crashkernel=Y,low" together, they
are strongly dependent, make code logic clear and more readable.

Suggested-by: Borislav Petkov <bp@xxxxxxxxx>
Signed-off-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx>
---
 arch/x86/kernel/setup.c | 21 +++++++++------------
 1 file changed, 9 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 6a190c7f4d71b05..93d78aae1937db3 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -416,18 +416,16 @@ static void __init memblock_x86_reserve_range_setup_data(void)
 # define CRASH_ADDR_HIGH_MAX	SZ_64T
 #endif
 
-static int __init reserve_crashkernel_low(void)
+static int __init reserve_crashkernel_low(unsigned long long low_size)
 {
 #ifdef CONFIG_X86_64
-	unsigned long long base, low_base = 0, low_size = 0;
+	unsigned long long low_base = 0;
 	unsigned long low_mem_limit;
-	int ret;
 
 	low_mem_limit = min(memblock_phys_mem_size(), CRASH_ADDR_LOW_MAX);
 
-	/* crashkernel=Y,low */
-	ret = parse_crashkernel_low(boot_command_line, low_mem_limit, &low_size, &base);
-	if (ret) {
+	/* crashkernel=Y,low is not specified */
+	if ((long)low_size < 0) {
 		/*
 		 * two parts from kernel/dma/swiotlb.c:
 		 * -swiotlb size: user-specified with swiotlb= or default.
@@ -465,7 +463,7 @@ static int __init reserve_crashkernel_low(void)
 
 static void __init reserve_crashkernel(void)
 {
-	unsigned long long crash_size, crash_base, total_mem;
+	unsigned long long crash_size, crash_base, total_mem, low_size;
 	bool high = false;
 	int ret;
 
@@ -474,10 +472,9 @@ static void __init reserve_crashkernel(void)
 	/* crashkernel=XM */
 	ret = parse_crashkernel(boot_command_line, total_mem, &crash_size, &crash_base);
 	if (ret != 0 || crash_size <= 0) {
-		/* crashkernel=X,high */
-		ret = parse_crashkernel_high(boot_command_line, total_mem,
-					     &crash_size, &crash_base);
-		if (ret != 0 || crash_size <= 0)
+		/* crashkernel=X,high and possible crashkernel=Y,low */
+		ret = parse_crashkernel_high_low(boot_command_line, &crash_size, &low_size);
+		if (ret)
 			return;
 		high = true;
 	}
@@ -520,7 +517,7 @@ static void __init reserve_crashkernel(void)
 		}
 	}
 
-	if (crash_base >= (1ULL << 32) && reserve_crashkernel_low()) {
+	if (crash_base >= (1ULL << 32) && reserve_crashkernel_low(low_size)) {
 		memblock_phys_free(crash_base, crash_size);
 		return;
 	}
-- 
2.25.1