arm64/mm: fix page table check compile error for CONFIG_PGTABLE_LEVELS=2

If CONFIG_PGTABLE_LEVELS=2 and CONFIG_ARCH_SUPPORTS_PAGE_TABLE_CHECK=y,
then we trigger a compile error:

  error: implicit declaration of function 'pte_user_accessible_page'

Move the definition of page table check helper out of branch
CONFIG_PGTABLE_LEVELS > 2

Link: https://lkml.kernel.org/r/20220517074548.2227779-3-tongtiangen@huawei.com
Fixes: daf214c14dbe ("arm64/mm: enable ARCH_SUPPORTS_PAGE_TABLE_CHECK")
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Guohanjun <guohanjun@huawei.com>
Cc: Xie XiuQi <xiexiuqi@huawei.com>
Cc: kernel test robot <lkp@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

arch/arm64/include/asm/pgtable.h

@@ -667,22 +667,6 @@ static inline unsigned long pmd_page_vaddr(pmd_t pmd)
 #define pud_valid(pud)		pte_valid(pud_pte(pud))
 #define pud_user(pud)		pte_user(pud_pte(pud))
 
-#ifdef CONFIG_PAGE_TABLE_CHECK
-static inline bool pte_user_accessible_page(pte_t pte)
-{
-	return pte_present(pte) && (pte_user(pte) || pte_user_exec(pte));
-}
-
-static inline bool pmd_user_accessible_page(pmd_t pmd)
-{
-	return pmd_present(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd));
-}
-
-static inline bool pud_user_accessible_page(pud_t pud)
-{
-	return pud_present(pud) && pud_user(pud);
-}
-#endif
 
 static inline void set_pud(pud_t *pudp, pud_t pud)
 {
@@ -855,6 +839,23 @@ static inline int pgd_devmap(pgd_t pgd)
 }
 #endif
 
+#ifdef CONFIG_PAGE_TABLE_CHECK
+static inline bool pte_user_accessible_page(pte_t pte)
+{
+	return pte_present(pte) && (pte_user(pte) || pte_user_exec(pte));
+}
+
+static inline bool pmd_user_accessible_page(pmd_t pmd)
+{
+	return pmd_present(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd));
+}
+
+static inline bool pud_user_accessible_page(pud_t pud)
+{
+	return pud_present(pud) && pud_user(pud);
+}
+#endif
+
 /*
  * Atomic pte/pmd modifications.
  */