arm64: mm: add missing P4D definitions and use them consistently

Even though level 0, 1 and 2 descriptors share the same attribute
encodings, let's be a bit more consistent about using the right one at
the right level. So add new macros for level 0/P4D definitions, and
clean up some inconsistencies involving these macros.
Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20210310104942.174584-2-ardb@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

arch/arm64/include/asm/pgalloc.h

@@ -27,7 +27,7 @@ static inline void __pud_populate(pud_t *pudp, phys_addr_t pmdp, pudval_t prot)
 
 static inline void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmdp)
 {
-	__pud_populate(pudp, __pa(pmdp), PMD_TYPE_TABLE);
+	__pud_populate(pudp, __pa(pmdp), PUD_TYPE_TABLE);
 }
 #else
 static inline void __pud_populate(pud_t *pudp, phys_addr_t pmdp, pudval_t prot)
@@ -45,7 +45,7 @@ static inline void __p4d_populate(p4d_t *p4dp, phys_addr_t pudp, p4dval_t prot)
 
 static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4dp, pud_t *pudp)
 {
-	__p4d_populate(p4dp, __pa(pudp), PUD_TYPE_TABLE);
+	__p4d_populate(p4dp, __pa(pudp), P4D_TYPE_TABLE);
 }
 #else
 static inline void __p4d_populate(p4d_t *p4dp, phys_addr_t pudp, p4dval_t prot)

arch/arm64/include/asm/pgtable-hwdef.h

@@ -94,6 +94,15 @@
 /*
  * Hardware page table definitions.
  *
+ * Level 0 descriptor (P4D).
+ */
+#define P4D_TYPE_TABLE		(_AT(p4dval_t, 3) << 0)
+#define P4D_TABLE_BIT		(_AT(p4dval_t, 1) << 1)
+#define P4D_TYPE_MASK		(_AT(p4dval_t, 3) << 0)
+#define P4D_TYPE_SECT		(_AT(p4dval_t, 1) << 0)
+#define P4D_SECT_RDONLY		(_AT(p4dval_t, 1) << 7)		/* AP[2] */
+
+/*
  * Level 1 descriptor (PUD).
  */
 #define PUD_TYPE_TABLE		(_AT(pudval_t, 3) << 0)

arch/arm64/mm/kasan_init.c

@@ -79,7 +79,7 @@ static pmd_t *__init kasan_pmd_offset(pud_t *pudp, unsigned long addr, int node,
 		phys_addr_t pmd_phys = early ?
 				__pa_symbol(kasan_early_shadow_pmd)
 					: kasan_alloc_zeroed_page(node);
-		__pud_populate(pudp, pmd_phys, PMD_TYPE_TABLE);
+		__pud_populate(pudp, pmd_phys, PUD_TYPE_TABLE);
 	}
 
 	return early ? pmd_offset_kimg(pudp, addr) : pmd_offset(pudp, addr);
@@ -92,7 +92,7 @@ static pud_t *__init kasan_pud_offset(p4d_t *p4dp, unsigned long addr, int node,
 		phys_addr_t pud_phys = early ?
 				__pa_symbol(kasan_early_shadow_pud)
 					: kasan_alloc_zeroed_page(node);
-		__p4d_populate(p4dp, pud_phys, PMD_TYPE_TABLE);
+		__p4d_populate(p4dp, pud_phys, P4D_TYPE_TABLE);
 	}
 
 	return early ? pud_offset_kimg(p4dp, addr) : pud_offset(p4dp, addr);

arch/arm64/mm/mmu.c

@@ -309,7 +309,7 @@ static void alloc_init_pud(pgd_t *pgdp, unsigned long addr, unsigned long end,
 		phys_addr_t pud_phys;
 		BUG_ON(!pgtable_alloc);
 		pud_phys = pgtable_alloc(PUD_SHIFT);
-		__p4d_populate(p4dp, pud_phys, PUD_TYPE_TABLE);
+		__p4d_populate(p4dp, pud_phys, P4D_TYPE_TABLE);
 		p4d = READ_ONCE(*p4dp);
 	}
 	BUG_ON(p4d_bad(p4d));
@@ -1210,11 +1210,11 @@ void __init early_fixmap_init(void)
 		pudp = pud_offset_kimg(p4dp, addr);
 	} else {
 		if (p4d_none(p4d))
-			__p4d_populate(p4dp, __pa_symbol(bm_pud), PUD_TYPE_TABLE);
+			__p4d_populate(p4dp, __pa_symbol(bm_pud), P4D_TYPE_TABLE);
 		pudp = fixmap_pud(addr);
 	}
 	if (pud_none(READ_ONCE(*pudp)))
-		__pud_populate(pudp, __pa_symbol(bm_pmd), PMD_TYPE_TABLE);
+		__pud_populate(pudp, __pa_symbol(bm_pmd), PUD_TYPE_TABLE);
 	pmdp = fixmap_pmd(addr);
 	__pmd_populate(pmdp, __pa_symbol(bm_pte), PMD_TYPE_TABLE);