[PATCH v11 1/5] arm64: kdump: add macro CRASH_ALIGN and CRASH_ADDR_LOW_MAX

[Chen Zhou]

Expose variable arm64_dma32_phys_limit for followup, and add macro
CRASH_ALIGN for alignment, macro CRASH_ADDR_LOW_MAX for upper bound
of low crash memory. Use macros instead.

Signed-off-by: Chen Zhou <chenzhou10 at huawei.com>
---
 arch/arm64/include/asm/kexec.h     | 5 +++++
 arch/arm64/include/asm/processor.h | 1 +
 arch/arm64/mm/init.c               | 8 ++++----
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h
index d24b527e8c00..1a2f27f12794 100644
--- a/arch/arm64/include/asm/kexec.h
+++ b/arch/arm64/include/asm/kexec.h
@@ -25,6 +25,11 @@
 
 #define KEXEC_ARCH KEXEC_ARCH_AARCH64
 
+/* 2M alignment for crash kernel regions */
+#define CRASH_ALIGN	SZ_2M
+
+#define CRASH_ADDR_LOW_MAX	arm64_dma32_phys_limit
+
 #ifndef __ASSEMBLY__
 
 /**
diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h
index 240fe5e5b720..af71063f352c 100644
--- a/arch/arm64/include/asm/processor.h
+++ b/arch/arm64/include/asm/processor.h
@@ -95,6 +95,7 @@
 #endif /* CONFIG_ARM64_FORCE_52BIT */
 
 extern phys_addr_t arm64_dma_phys_limit;
+extern phys_addr_t arm64_dma32_phys_limit;
 #define ARCH_LOW_ADDRESS_LIMIT	(arm64_dma_phys_limit - 1)
 
 struct debug_info {
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 1e93cfc7c47a..a3d0193f6a0a 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -67,7 +67,7 @@ EXPORT_SYMBOL(vmemmap);
  * bit addressable memory area.
  */
 phys_addr_t arm64_dma_phys_limit __ro_after_init;
-static phys_addr_t arm64_dma32_phys_limit __ro_after_init;
+phys_addr_t arm64_dma32_phys_limit __ro_after_init;
 
 #ifdef CONFIG_KEXEC_CORE
 /*
@@ -92,8 +92,8 @@ static void __init reserve_crashkernel(void)
 
 	if (crash_base == 0) {
 		/* Current arm64 boot protocol requires 2MB alignment */
-		crash_base = memblock_find_in_range(0, arm64_dma32_phys_limit,
-				crash_size, SZ_2M);
+		crash_base = memblock_find_in_range(0, CRASH_ADDR_LOW_MAX,
+				crash_size, CRASH_ALIGN);
 		if (crash_base == 0) {
 			pr_warn("cannot allocate crashkernel (size:0x%llx)\n",
 				crash_size);
@@ -111,7 +111,7 @@ static void __init reserve_crashkernel(void)
 			return;
 		}
 
-		if (!IS_ALIGNED(crash_base, SZ_2M)) {
+		if (!IS_ALIGNED(crash_base, CRASH_ALIGN)) {
 			pr_warn("cannot reserve crashkernel: base address is not 2MB aligned\n");
 			return;
 		}
-- 
2.20.1