mm: prefer xxx_page() alloc/free functions for order-0 pages

Update instances of alloc_pages(..., 0), __get_free_pages(..., 0) and
__free_pages(..., 0) to use alloc_page(), __get_free_page() and
__free_page() respectively in core code.

Link: https://lkml.kernel.org/r/50c48ca4789f1da2a65795f2346f5ae3eff7d665.1678710232.git.lstoakes@gmail.comSigned-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

include/asm-generic/pgalloc.h

@@ -123,11 +123,11 @@ static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
 
 	if (mm == &init_mm)
 		gfp = GFP_PGTABLE_KERNEL;
-	page = alloc_pages(gfp, 0);
+	page = alloc_page(gfp);
 	if (!page)
 		return NULL;
 	if (!pgtable_pmd_page_ctor(page)) {
-		__free_pages(page, 0);
+		__free_page(page);
 		return NULL;
 	}
 	return (pmd_t *)page_address(page);

mm/debug_vm_pgtable.c

@@ -1048,7 +1048,7 @@ static void __init destroy_args(struct pgtable_debug_args *args)
 
 	if (args->pte_pfn != ULONG_MAX) {
 		page = pfn_to_page(args->pte_pfn);
-		__free_pages(page, 0);
+		__free_page(page);
 
 		args->pte_pfn = ULONG_MAX;
 	}
@@ -1290,7 +1290,7 @@ static int __init init_args(struct pgtable_debug_args *args)
 		}
 	}
 
-	page = alloc_pages(GFP_KERNEL, 0);
+	page = alloc_page(GFP_KERNEL);
 	if (page)
 		args->pte_pfn = page_to_pfn(page);
 

mm/hugetlb_vmemmap.c

@@ -400,7 +400,7 @@ static int alloc_vmemmap_page_list(unsigned long start, unsigned long end,
 	return 0;
 out:
 	list_for_each_entry_safe(page, next, list, lru)
-		__free_pages(page, 0);
+		__free_page(page);
 	return -ENOMEM;
 }
 

mm/mmu_gather.c

@@ -32,7 +32,7 @@ static bool tlb_next_batch(struct mmu_gather *tlb)
 	if (tlb->batch_count == MAX_GATHER_BATCH_COUNT)
 		return false;
 
-	batch = (void *)__get_free_pages(GFP_NOWAIT | __GFP_NOWARN, 0);
+	batch = (void *)__get_free_page(GFP_NOWAIT | __GFP_NOWARN);
 	if (!batch)
 		return false;
 

mm/page_alloc.c

@@ -5558,7 +5558,7 @@ EXPORT_SYMBOL(__get_free_pages);
 
 unsigned long get_zeroed_page(gfp_t gfp_mask)
 {
-	return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
+	return __get_free_page(gfp_mask | __GFP_ZERO);
 }
 EXPORT_SYMBOL(get_zeroed_page);
 

mm/vmalloc.c

@@ -2739,7 +2739,7 @@ void vfree(const void *addr)
 		 * High-order allocs for huge vmallocs are split, so
 		 * can be freed as an array of order-0 allocations
 		 */
-		__free_pages(page, 0);
+		__free_page(page);
 		cond_resched();
 	}
 	atomic_long_sub(vm->nr_pages, &nr_vmalloc_pages);