Subject: [PATCH v4 06/15] arm64: mm: Drop redundant pgd_t* argument from map_mem()

From: Ard Biesheuvel <[email-masked]>
Date: Mon, 27 Apr 2026 17:34:23 +0200

From: Ard Biesheuvel <[email-masked]>

__map_memblock() and map_mem() always operate on swapper_pg_dir, so
there is no need to pass around a pgd_t pointer between them.

Reviewed-by: Ryan Roberts <[email-masked]>
Signed-off-by: Ard Biesheuvel <[email-masked]>
---
 arch/arm64/mm/mmu.c | 25 ++++++++++----------
 1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index bfbf3fe0d1be..9610dd2d7bd9 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -1039,11 +1039,11 @@ static void update_mapping_prot(phys_addr_t phys, unsigned long virt,
 	flush_tlb_kernel_range(virt, virt + size);
 }
 
-static void __init __map_memblock(pgd_t *pgdp, phys_addr_t start,
-				  phys_addr_t end, pgprot_t prot, int flags)
+static void __init __map_memblock(phys_addr_t start, phys_addr_t end,
+				  pgprot_t prot, int flags)
 {
-	early_create_pgd_mapping(pgdp, start, __phys_to_virt(start), end - start,
-				 prot, early_pgtable_alloc, flags);
+	early_create_pgd_mapping(swapper_pg_dir, start, __phys_to_virt(start),
+				 end - start, prot, early_pgtable_alloc, flags);
 }
 
 void __init mark_linear_text_alias_ro(void)
@@ -1091,13 +1091,13 @@ static phys_addr_t __init arm64_kfence_alloc_pool(void)
 	return kfence_pool;
 }
 
-static void __init arm64_kfence_map_pool(phys_addr_t kfence_pool, pgd_t *pgdp)
+static void __init arm64_kfence_map_pool(phys_addr_t kfence_pool)
 {
 	if (!kfence_pool)
 		return;
 
 	/* KFENCE pool needs page-level mapping. */
-	__map_memblock(pgdp, kfence_pool, kfence_pool + KFENCE_POOL_SIZE,
+	__map_memblock(kfence_pool, kfence_pool + KFENCE_POOL_SIZE,
 			pgprot_tagged(PAGE_KERNEL),
 			NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS);
 	memblock_clear_nomap(kfence_pool, KFENCE_POOL_SIZE);
@@ -1133,11 +1133,11 @@ bool arch_kfence_init_pool(void)
 #else /* CONFIG_KFENCE */
 
 static inline phys_addr_t arm64_kfence_alloc_pool(void) { return 0; }
-static inline void arm64_kfence_map_pool(phys_addr_t kfence_pool, pgd_t *pgdp) { }
+static inline void arm64_kfence_map_pool(phys_addr_t kfence_pool) { }
 
 #endif /* CONFIG_KFENCE */
 
-static void __init map_mem(pgd_t *pgdp)
+static void __init map_mem(void)
 {
 	static const u64 direct_map_end = _PAGE_END(VA_BITS_MIN);
 	phys_addr_t kernel_start = __pa_symbol(_text);
@@ -1182,7 +1182,7 @@ static void __init map_mem(pgd_t *pgdp)
 		 * if MTE is present. Otherwise, it has the same attributes as
 		 * PAGE_KERNEL.
 		 */
-		__map_memblock(pgdp, start, end, pgprot_tagged(PAGE_KERNEL),
+		__map_memblock(start, end, pgprot_tagged(PAGE_KERNEL),
 			       flags);
 	}
 
@@ -1196,10 +1196,9 @@ static void __init map_mem(pgd_t *pgdp)
 	 * Note that contiguous mappings cannot be remapped in this way,
 	 * so we should avoid them here.
 	 */
-	__map_memblock(pgdp, kernel_start, kernel_end,
-		       PAGE_KERNEL, NO_CONT_MAPPINGS);
+	__map_memblock(kernel_start, kernel_end, PAGE_KERNEL, NO_CONT_MAPPINGS);
 	memblock_clear_nomap(kernel_start, kernel_end - kernel_start);
-	arm64_kfence_map_pool(early_kfence_pool, pgdp);
+	arm64_kfence_map_pool(early_kfence_pool);
 }
 
 void mark_rodata_ro(void)
@@ -1421,7 +1420,7 @@ static void __init create_idmap(void)
 
 void __init paging_init(void)
 {
-	map_mem(swapper_pg_dir);
+	map_mem();
 
 	memblock_allow_resize();
 
-- 
2.54.0.rc2.544.gc7ae2d5bb8-goog