riscv: mm: Refactor create_linear_mapping_range() for memory hot add

Add a parameter to the direct map setup function, so it can be used in
arch_add_memory() later.

Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20240605114100.315918-5-bjorn@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Author: bjorn-rivos

arch/riscv/mm/init.c

@@ -1231,7 +1231,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
 }
 
 static void __meminit create_linear_mapping_range(phys_addr_t start, phys_addr_t end,
-						  uintptr_t fixed_map_size)
+						  uintptr_t fixed_map_size, const pgprot_t *pgprot)
 {
 	phys_addr_t pa;
 	uintptr_t va, map_size;
@@ -1242,7 +1242,7 @@ static void __meminit create_linear_mapping_range(phys_addr_t start, phys_addr_t
 					    best_map_size(pa, va, end - pa);
 
 		create_pgd_mapping(swapper_pg_dir, va, pa, map_size,
-				   pgprot_from_va(va));
+				   pgprot ? *pgprot : pgprot_from_va(va));
 	}
 }
 
@@ -1286,22 +1286,19 @@ static void __init create_linear_mapping_page_table(void)
 		if (end >= __pa(PAGE_OFFSET) + memory_limit)
 			end = __pa(PAGE_OFFSET) + memory_limit;
 
-		create_linear_mapping_range(start, end, 0);
+		create_linear_mapping_range(start, end, 0, NULL);
 	}
 
 #ifdef CONFIG_STRICT_KERNEL_RWX
-	create_linear_mapping_range(ktext_start, ktext_start + ktext_size, 0);
-	create_linear_mapping_range(krodata_start,
-				    krodata_start + krodata_size, 0);
+	create_linear_mapping_range(ktext_start, ktext_start + ktext_size, 0, NULL);
+	create_linear_mapping_range(krodata_start, krodata_start + krodata_size, 0, NULL);
 
 	memblock_clear_nomap(ktext_start,  ktext_size);
 	memblock_clear_nomap(krodata_start, krodata_size);
 #endif
 
 #ifdef CONFIG_KFENCE
-	create_linear_mapping_range(kfence_pool,
-				    kfence_pool + KFENCE_POOL_SIZE,
-				    PAGE_SIZE);
+	create_linear_mapping_range(kfence_pool, kfence_pool + KFENCE_POOL_SIZE, PAGE_SIZE, NULL);
 
 	memblock_clear_nomap(kfence_pool, KFENCE_POOL_SIZE);
 #endif