sparc64: implement page mapping percpu first chunk allocator

Implement page mapping percpu first chunk allocator as a fallback to
the embedding allocator.  The next patch will make the embedding
allocator check distances between units to determine whether it fits
within the vmalloc area so that this fallback can be used on such
cases.

sparc64 currently has relatively small vmalloc area which makes it
impossible to create any dynamic chunks on certain configurations
leading to percpu allocation failures.  This and the next patch should
allow those configurations to keep working until proper solution is
found.

While at it, mark pcpu_cpu_distance() with __init.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 0 deletions

diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 97fca4695e0b..ac45aab741a5 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -102,6 +102,9 @@ config HAVE_SETUP_PER_CPU_AREA
 config NEED_PER_CPU_EMBED_FIRST_CHUNK
         def_bool y if SPARC64
 
+config NEED_PER_CPU_PAGE_FIRST_CHUNK
+        def_bool y if SPARC64
+
 config GENERIC_HARDIRQS_NO__DO_IRQ
         bool
         def_bool y if SPARC64