[RFC PATCH] ARM: Support allocating crashkernel above 4G for LPAE

[Jinjie Ruan]

As ARM LPAE feature support accessing memory beyond the 4G limit, define
HAVE_ARCH_CRASHKERNEL_RESERVATION_HIGH macro to support reserving crash
memory above 4G for ARM32 LPAE.

No test because there is no LPAE ARM32 hardware.

Signed-off-by: Jinjie Ruan <ruanjinjie at huawei.com>
---
 arch/arm/include/asm/crash_reserve.h | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/arm/include/asm/crash_reserve.h b/arch/arm/include/asm/crash_reserve.h
index 85c9298bd3b7..33a2f18b0ec1 100644
--- a/arch/arm/include/asm/crash_reserve.h
+++ b/arch/arm/include/asm/crash_reserve.h
@@ -19,6 +19,10 @@ static inline unsigned long crash_addr_low_max(void)
 	return (crash_max > lowmem_max) ? lowmem_max : crash_max;
 }
 
-
 #define HAVE_ARCH_ADD_CRASH_RES_TO_IOMEM_EARLY
+
+#if defined(CONFIG_ARM_LPAE) && defined(CONFIG_HIGHMEM)
+#define HAVE_ARCH_CRASHKERNEL_RESERVATION_HIGH
+#endif
+
 #endif
-- 
2.34.1