riscv: Use PMD_SIZE to replace PTE_PARENT_SIZE

The PMD_SIZE is equal to PGDIR_SIZE when __PAGETABLE_PMD_FOLDED is
defined.
Signed-off-by: NZong Li <zong.li@sifive.com>
Reviewed-by: NAnup Patel <anup@brainfault.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
[paul.walmsley@sifive.com: fixed spelling in commit summary]
Signed-off-by: NPaul Walmsley <paul.walmsley@sifive.com>

arch/riscv/mm/init.c

@@ -273,7 +273,6 @@ static void __init create_pmd_mapping(pmd_t *pmdp,
 #define get_pgd_next_virt(__pa)	get_pmd_virt(__pa)
 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
 	create_pmd_mapping(__nextp, __va, __pa, __sz, __prot)
-#define PTE_PARENT_SIZE		PMD_SIZE
 #define fixmap_pgd_next		fixmap_pmd
 #else
 #define pgd_next_t		pte_t
@@ -281,7 +280,6 @@ static void __init create_pmd_mapping(pmd_t *pmdp,
 #define get_pgd_next_virt(__pa)	get_pte_virt(__pa)
 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
 	create_pte_mapping(__nextp, __va, __pa, __sz, __prot)
-#define PTE_PARENT_SIZE		PGDIR_SIZE
 #define fixmap_pgd_next		fixmap_pte
 #endif
 
@@ -314,14 +312,11 @@ static void __init create_pgd_mapping(pgd_t *pgdp,
 
 static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size)
 {
-	uintptr_t map_size = PAGE_SIZE;
+	/* Upgrade to PMD_SIZE mappings whenever possible */
+	if ((base & (PMD_SIZE - 1)) || (size & (PMD_SIZE - 1)))
+		return PAGE_SIZE;
 
-	/* Upgrade to PMD/PGDIR mappings whenever possible */
-	if (!(base & (PTE_PARENT_SIZE - 1)) &&
-	    !(size & (PTE_PARENT_SIZE - 1)))
-		map_size = PTE_PARENT_SIZE;
-
-	return map_size;
+	return PMD_SIZE;
 }
 
 /*