[PATCH v18 13/17] arm64: kdump: introduce some macros for crash kernel reservation

[Zhen Lei <thunder.leizhen@huawei.com>]

From: Chen Zhou <chenzhou10@huawei.com>

Introduce macro CRASH_ALIGN for alignment, macro CRASH_ADDR_LOW_MAX
for upper bound of low crash memory, macro CRASH_ADDR_HIGH_MAX for
upper bound of high crash memory, use macros instead.

Besides, keep consistent with x86, use CRASH_ALIGN as the lower bound
of crash kernel reservation.

Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Tested-by: John Donnelly <John.p.donnelly@oracle.com>
Tested-by: Dave Kleikamp <dave.kleikamp@oracle.com>
---
 arch/arm64/include/asm/kexec.h | 6 ++++++
 arch/arm64/mm/init.c           | 4 ++--
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h
index 9839bfc163d7147..1b9edc69f0244ca 100644
--- a/arch/arm64/include/asm/kexec.h
+++ b/arch/arm64/include/asm/kexec.h
@@ -25,6 +25,12 @@
 
 #define KEXEC_ARCH KEXEC_ARCH_AARCH64
 
+/* 2M alignment for crash kernel regions */
+#define CRASH_ALIGN	SZ_2M
+
+#define CRASH_ADDR_LOW_MAX	arm64_dma_phys_limit
+#define CRASH_ADDR_HIGH_MAX	MEMBLOCK_ALLOC_ACCESSIBLE
+
 #ifndef __ASSEMBLY__
 
 /**
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index a8834434af99ae0..be4595dc7459115 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -75,7 +75,7 @@ phys_addr_t arm64_dma_phys_limit __ro_after_init;
 static void __init reserve_crashkernel(void)
 {
 	unsigned long long crash_base, crash_size;
-	unsigned long long crash_max = arm64_dma_phys_limit;
+	unsigned long long crash_max = CRASH_ADDR_LOW_MAX;
 	int ret;
 
 	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
@@ -91,7 +91,7 @@ static void __init reserve_crashkernel(void)
 		crash_max = crash_base + crash_size;
 
 	/* Current arm64 boot protocol requires 2MB alignment */
-	crash_base = memblock_phys_alloc_range(crash_size, SZ_2M,
+	crash_base = memblock_phys_alloc_range(crash_size, CRASH_ALIGN,
 					       crash_base, crash_max);
 	if (!crash_base) {
 		pr_warn("cannot allocate crashkernel (size:0x%llx)\n",
-- 
2.25.1