x86,percpu: generalize lpage first chunk allocator

Generalize and move x86 setup_pcpu_lpage() into
pcpu_lpage_first_chunk().  setup_pcpu_lpage() now is a simple wrapper
around the generalized version.  Other than taking size parameters and
using arch supplied callbacks to allocate/free/map memory,
pcpu_lpage_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, factor out pcpu_calc_fc_sizes() which is common to
pcpu_embed_first_chunk() and pcpu_lpage_first_chunk().

[ Impact: code reorganization and generalization ]

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

1 files changed, 27 insertions, 0 deletions

diff --git a/include/linux/percpu.h b/include/linux/percpu.h
index 41b5bfab4195..9f6bfd7d4b92 100644
--- a/include/linux/percpu.h
+++ b/include/linux/percpu.h
@@ -62,6 +62,7 @@ typedef struct page * (*pcpu_get_page_fn_t)(unsigned int cpu, int pageno);
 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);
+typedef void (*pcpu_fc_map_fn_t)(void *ptr, size_t size, void *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,
@@ -79,6 +80,32 @@ extern ssize_t __init pcpu_4k_first_chunk(
                                 pcpu_fc_free_fn_t free_fn,
                                 pcpu_fc_populate_pte_fn_t populate_pte_fn);
 
+#ifdef CONFIG_NEED_MULTIPLE_NODES
+extern ssize_t __init pcpu_lpage_first_chunk(
+                                size_t static_size, size_t reserved_size,
+                                ssize_t dyn_size, size_t lpage_size,
+                                pcpu_fc_alloc_fn_t alloc_fn,
+                                pcpu_fc_free_fn_t free_fn,
+                                pcpu_fc_map_fn_t map_fn);
+
+extern void *pcpu_lpage_remapped(void *kaddr);
+#else
+static inline ssize_t __init pcpu_lpage_first_chunk(
+                                size_t static_size, size_t reserved_size,
+                                ssize_t dyn_size, size_t lpage_size,
+                                pcpu_fc_alloc_fn_t alloc_fn,
+                                pcpu_fc_free_fn_t free_fn,
+                                pcpu_fc_map_fn_t map_fn)
+{
+        return -EINVAL;
+}
+
+static inline void *pcpu_lpage_remapped(void *kaddr)
+{
+        return NULL;
+}
+#endif
+
 /*
  * Use this to get to a cpu's version of the per-cpu object
  * dynamically allocated. Non-atomic access to the current CPU's