percpu: convert chunk hints to be based on pcpu_block_md

As mentioned in the last patch, a chunk's hints are no different than a
block just responsible for more bits. This converts chunk level hints to
use a pcpu_block_md to maintain them. This lets us reuse the same hint
helper functions as a block. The left_free and right_free are unused by
the chunk's pcpu_block_md.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
diff --git a/mm/percpu-stats.c b/mm/percpu-stats.c
index b5fdd43..ef5034a 100644
--- a/mm/percpu-stats.c
+++ b/mm/percpu-stats.c
@@ -53,6 +53,7 @@ static int find_max_nr_alloc(void)
 static void chunk_map_stats(struct seq_file *m, struct pcpu_chunk *chunk,
 			    int *buffer)
 {
+	struct pcpu_block_md *chunk_md = &chunk->chunk_md;
 	int i, last_alloc, as_len, start, end;
 	int *alloc_sizes, *p;
 	/* statistics */
@@ -121,9 +122,9 @@ static void chunk_map_stats(struct seq_file *m, struct pcpu_chunk *chunk,
 	P("nr_alloc", chunk->nr_alloc);
 	P("max_alloc_size", chunk->max_alloc_size);
 	P("empty_pop_pages", chunk->nr_empty_pop_pages);
-	P("first_bit", chunk->first_bit);
+	P("first_bit", chunk_md->first_free);
 	P("free_bytes", chunk->free_bytes);
-	P("contig_bytes", chunk->contig_bits * PCPU_MIN_ALLOC_SIZE);
+	P("contig_bytes", chunk_md->contig_hint * PCPU_MIN_ALLOC_SIZE);
 	P("sum_frag", sum_frag);
 	P("max_frag", max_frag);
 	P("cur_min_alloc", cur_min_alloc);