use common kfence macro KFENCE_POOL_SIZE for KFENCE_AREA_SIZE definition

Signed-off-by: yuan linyu <yuanlinyu@honor.com>
---
 arch/loongarch/include/asm/pgtable.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/loongarch/include/asm/pgtable.h b/arch/loongarch/include/asm/pgtable.h
index f41a648a3d9e..e9966c9f844f 100644
--- a/arch/loongarch/include/asm/pgtable.h
+++ b/arch/loongarch/include/asm/pgtable.h
@@ -10,6 +10,7 @@
 #define _ASM_PGTABLE_H
 
 #include <linux/compiler.h>
+#include <linux/kfence.h>
 #include <asm/addrspace.h>
 #include <asm/asm.h>
 #include <asm/page.h>
@@ -96,7 +97,7 @@ extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
 #define MODULES_END	(MODULES_VADDR + SZ_256M)
 
 #ifdef CONFIG_KFENCE
-#define KFENCE_AREA_SIZE	(((CONFIG_KFENCE_NUM_OBJECTS + 1) * 2 + 2) * PAGE_SIZE)
+#define KFENCE_AREA_SIZE	(KFENCE_POOL_SIZE + (2 * PAGE_SIZE))
 #else
 #define KFENCE_AREA_SIZE	0
 #endif
-- 
2.25.1