of: Only compile OF_DYNAMIC on PowerPC pseries and iseries

Only two architectures use the OF node reference counting and reclaim bits.
There is no need to compile it for the rest of the PowerPC platforms or for
any of the other architectures.  This patch makes iseries and pseries
select CONFIG_OF_DYNAMIC, and makes it default to off for everything else.

It is still safe to turn on CONFIG_OF_DYNAMIC on all architectures, it just
isn't necessary.

v2: Also select OF_DYNAMIC for PPC_CHROMA and MPC885ADS as reported by Michael
    Meuling

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Jimi Xenidis <jimix@pobox.com> (for PPC_CHROMA bug fix)
Cc: Rob Herring <rob.herring@calxeda.com>

7 files changed, 15 insertions, 12 deletions

diff --git a/arch/powerpc/platforms/8xx/Kconfig b/arch/powerpc/platforms/8xx/Kconfig
index ee56a9ea6a79..1fb0b3cddeb3 100644
--- a/arch/powerpc/platforms/8xx/Kconfig
+++ b/arch/powerpc/platforms/8xx/Kconfig
@@ -26,6 +26,7 @@ config MPC86XADS
 config MPC885ADS
         bool "MPC885ADS"
         select CPM1
+        select OF_DYNAMIC
         help
           Freescale Semiconductor MPC885 Application Development System (ADS).
           Also known as DUET.
diff --git a/arch/powerpc/platforms/iseries/Kconfig b/arch/powerpc/platforms/iseries/Kconfig
index b57cda3a0817..63835e09e5cc 100644
--- a/arch/powerpc/platforms/iseries/Kconfig
+++ b/arch/powerpc/platforms/iseries/Kconfig
@@ -1,6 +1,7 @@
 config PPC_ISERIES
         bool "IBM Legacy iSeries"
         depends on PPC64 && PPC_BOOK3S
+        select OF_DYNAMIC
         select PPC_SMP_MUXED_IPI
         select PPC_INDIRECT_PIO
         select PPC_INDIRECT_MMIO
diff --git a/arch/powerpc/platforms/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig
index ae7b6d41fed3..1114f8f336df 100644
--- a/arch/powerpc/platforms/pseries/Kconfig
+++ b/arch/powerpc/platforms/pseries/Kconfig
@@ -3,6 +3,7 @@ config PPC_PSERIES
         bool "IBM pSeries & new (POWER5-based) iSeries"
         select HAVE_PCSPKR_PLATFORM
         select MPIC
+        select OF_DYNAMIC
         select PCI_MSI
         select PPC_XICS
         select PPC_ICP_NATIVE
diff --git a/arch/powerpc/platforms/wsp/Kconfig b/arch/powerpc/platforms/wsp/Kconfig
index 57d22a2f4ba9..79d2225b7608 100644
--- a/arch/powerpc/platforms/wsp/Kconfig
+++ b/arch/powerpc/platforms/wsp/Kconfig
@@ -25,6 +25,7 @@ config PPC_CHROMA
         bool "PowerEN PCIe Chroma Card"
         select EPAPR_BOOT
         select PPC_WSP
+        select OF_DYNAMIC
         default y
 
 endmenu
diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
index 268163dd71c7..6ea51dcbc728 100644
--- a/drivers/of/Kconfig
+++ b/drivers/of/Kconfig
@@ -35,9 +35,10 @@ config OF_EARLY_FLATTREE
 config OF_PROMTREE
         bool
 
+# Hardly any platforms need this.  It is safe to select, but only do so if you
+# need it.
 config OF_DYNAMIC
-        def_bool y
-        depends on PPC_OF
+        bool
 
 config OF_ADDRESS
         def_bool y
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 13ba72875e25..580644986945 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -88,7 +88,7 @@ int of_n_size_cells(struct device_node *np)
 }
 EXPORT_SYMBOL(of_n_size_cells);
 
-#if !defined(CONFIG_SPARC)   /* SPARC doesn't do ref counting (yet) */
+#if defined(CONFIG_OF_DYNAMIC)
 /**
  *      of_node_get - Increment refcount of a node
  *      @node:  Node to inc refcount, NULL is supported to
@@ -161,7 +161,7 @@ void of_node_put(struct device_node *node)
                 kref_put(&node->kref, of_node_release);
 }
 EXPORT_SYMBOL(of_node_put);
-#endif /* !CONFIG_SPARC */
+#endif /* CONFIG_OF_DYNAMIC */
 
 struct property *of_find_property(const struct device_node *np,
                                   const char *name,
diff --git a/include/linux/of.h b/include/linux/of.h
index 5a4a3adb17e5..533603e26b9b 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -72,19 +72,17 @@ struct of_phandle_args {
         uint32_t args[MAX_PHANDLE_ARGS];
 };
 
-#if defined(CONFIG_SPARC) || !defined(CONFIG_OF)
+#ifdef CONFIG_OF_DYNAMIC
+extern struct device_node *of_node_get(struct device_node *node);
+extern void of_node_put(struct device_node *node);
+#else /* CONFIG_OF_DYNAMIC */
 /* Dummy ref counting routines - to be implemented later */
 static inline struct device_node *of_node_get(struct device_node *node)
 {
         return node;
 }
-static inline void of_node_put(struct device_node *node)
-{
-}
-#else
-extern struct device_node *of_node_get(struct device_node *node);
-extern void of_node_put(struct device_node *node);
-#endif
+static inline void of_node_put(struct device_node *node) { }
+#endif /* !CONFIG_OF_DYNAMIC */
 
 #ifdef CONFIG_OF