perpcu: fold pcpu_split_block() into the only caller

... and simplify the results a bit.  Makes the next step easier
to deal with - we will be changing the data representation for
chunk->map[] and it's easier to do if the code in question is
not split between pcpu_alloc_area() and pcpu_split_block().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 16 insertions, 47 deletions

diff --git a/mm/percpu.c b/mm/percpu.c
index 036cfe07050f..592f289819b7 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -418,48 +418,6 @@ out_unlock:
 }
 
 /**
- * pcpu_split_block - split a map block
- * @chunk: chunk of interest
- * @i: index of map block to split
- * @head: head size in bytes (can be 0)
- * @tail: tail size in bytes (can be 0)
- *
- * Split the @i'th map block into two or three blocks.  If @head is
- * non-zero, @head bytes block is inserted before block @i moving it
- * to @i+1 and reducing its size by @head bytes.
- *
- * If @tail is non-zero, the target block, which can be @i or @i+1
- * depending on @head, is reduced by @tail bytes and @tail byte block
- * is inserted after the target block.
- *
- * @chunk->map must have enough free slots to accommodate the split.
- *
- * CONTEXT:
- * pcpu_lock.
- */
-static void pcpu_split_block(struct pcpu_chunk *chunk, int i,
-                             int head, int tail)
-{
-        int nr_extra = !!head + !!tail;
-
-        BUG_ON(chunk->map_alloc < chunk->map_used + nr_extra);
-
-        /* insert new subblocks */
-        memmove(&chunk->map[i + nr_extra], &chunk->map[i],
-                sizeof(chunk->map[0]) * (chunk->map_used - i));
-        chunk->map_used += nr_extra;
-
-        if (head) {
-                chunk->map[i + 1] = chunk->map[i] - head;
-                chunk->map[i++] = head;
-        }
-        if (tail) {
-                chunk->map[i++] -= tail;
-                chunk->map[i] = tail;
-        }
-}
-
-/**
  * pcpu_alloc_area - allocate area from a pcpu_chunk
  * @chunk: chunk of interest
  * @size: wanted size in bytes
@@ -524,14 +482,25 @@ static int pcpu_alloc_area(struct pcpu_chunk *chunk, int size, int align)
 
                 /* split if warranted */
                 if (head || tail) {
-                        pcpu_split_block(chunk, i, head, tail);
+                        int nr_extra = !!head + !!tail;
+
+                        /* insert new subblocks */
+                        memmove(&chunk->map[i + nr_extra], &chunk->map[i],
+                                sizeof(chunk->map[0]) * (chunk->map_used - i));
+                        chunk->map_used += nr_extra;
+
                         if (head) {
-                                i++;
+                                chunk->map[i + 1] = chunk->map[i] - head;
+                                chunk->map[i] = head;
                                 off += head;
-                                max_contig = max(chunk->map[i - 1], max_contig);
+                                i++;
+                                max_contig = max(head, max_contig);
+                        }
+                        if (tail) {
+                                chunk->map[i] -= tail;
+                                chunk->map[i + 1] = tail;
+                                max_contig = max(tail, max_contig);
                         }
-                        if (tail)
-                                max_contig = max(chunk->map[i + 1], max_contig);
                 }
 
                 /* update hint and mark allocated */