x86,percpu: generalize 4k first chunk allocator

Generalize and move x86 setup_pcpu_4k() into pcpu_4k_first_chunk().
setup_pcpu_4k() now is a simple wrapper around the generalized
version.  Other than taking size parameters and using arch supplied
callbacks to allocate/free memory, pcpu_4k_first_chunk() is identical
to the original implementation.

This simplifies arch code and will help converting more archs to
dynamic percpu allocator.

While at it, s/pcpu_populate_pte_fn_t/pcpu_fc_populate_pte_fn_t/ for
consistency.

[ Impact: code reorganization and generalization ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>

1 files changed, 10 insertions, 2 deletions

diff --git a/include/linux/percpu.h b/include/linux/percpu.h
index 83bff053bd1c..41b5bfab4195 100644
--- a/include/linux/percpu.h
+++ b/include/linux/percpu.h
@@ -59,18 +59,26 @@
 extern void *pcpu_base_addr;
 
 typedef struct page * (*pcpu_get_page_fn_t)(unsigned int cpu, int pageno);
-typedef void (*pcpu_populate_pte_fn_t)(unsigned long addr);
+typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size);
+typedef void (*pcpu_fc_free_fn_t)(void *ptr, size_t size);
+typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr);
 
 extern size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn,
                                 size_t static_size, size_t reserved_size,
                                 ssize_t dyn_size, ssize_t unit_size,
                                 void *base_addr,
-                                pcpu_populate_pte_fn_t populate_pte_fn);
+                                pcpu_fc_populate_pte_fn_t populate_pte_fn);
 
 extern ssize_t __init pcpu_embed_first_chunk(
                                 size_t static_size, size_t reserved_size,
                                 ssize_t dyn_size);
 
+extern ssize_t __init pcpu_4k_first_chunk(
+                                size_t static_size, size_t reserved_size,
+                                pcpu_fc_alloc_fn_t alloc_fn,
+                                pcpu_fc_free_fn_t free_fn,
+                                pcpu_fc_populate_pte_fn_t populate_pte_fn);
+
 /*
  * Use this to get to a cpu's version of the per-cpu object
  * dynamically allocated. Non-atomic access to the current CPU's