mm/page_alloc: use helper macro SZ_1{K,M}

Use helper macro SZ_1K and SZ_1M to do the size conversion.  Minor
readability improvement.

Link: https://lkml.kernel.org/r/20220916072257.9639-13-linmiaohe@huawei.comSigned-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/page_alloc.c

@@ -7056,7 +7056,7 @@ static int zone_batchsize(struct zone *zone)
 	 * size is striking a balance between allocation latency
 	 * and zone lock contention.
 	 */
-	batch = min(zone_managed_pages(zone) >> 10, (1024 * 1024) / PAGE_SIZE);
+	batch = min(zone_managed_pages(zone) >> 10, SZ_1M / PAGE_SIZE);
 	batch /= 4;		/* We effectively *= 4 below */
 	if (batch < 1)
 		batch = 1;
@@ -8531,8 +8531,8 @@ void __init mem_init_print_info(void)
 #endif
 		")\n",
 		K(nr_free_pages()), K(physpages),
-		codesize >> 10, datasize >> 10, rosize >> 10,
-		(init_data_size + init_code_size) >> 10, bss_size >> 10,
+		codesize / SZ_1K, datasize / SZ_1K, rosize / SZ_1K,
+		(init_data_size + init_code_size) / SZ_1K, bss_size / SZ_1K,
 		K(physpages - totalram_pages() - totalcma_pages),
 		K(totalcma_pages)
 #ifdef	CONFIG_HIGHMEM
@@ -9057,8 +9057,8 @@ void *__init alloc_large_system_hash(const char *tablename,
 		numentries -= arch_reserved_kernel_pages();
 
 		/* It isn't necessary when PAGE_SIZE >= 1MB */
-		if (PAGE_SHIFT < 20)
-			numentries = round_up(numentries, (1<<20)/PAGE_SIZE);
+		if (PAGE_SIZE < SZ_1M)
+			numentries = round_up(numentries, SZ_1M / PAGE_SIZE);
 
 #if __BITS_PER_LONG > 32
 		if (!high_limit) {