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

Kevin Brodsky
2026-04-28T14:33:29Z

On 27/04/2026 17:34, Ard Biesheuvel wrote:
> From: Ard Biesheuvel <ardb@kernel.org>
>
> __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 <ryan.roberts@arm.com>
> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>

> ---
> 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();
>