[PATCH 08/10] arch: introduce strict_ioremap

[Dan Williams]

In preparation for enabling memremap(), add support for strict mappings.
strict_ioremap_<type>() returns NULL if the arch does not implement the
mapping type, rather than falling back silently to ioremap().

Signed-off-by: Dan Williams <dan.j.williams at intel.com>
---
 include/linux/io.h |   21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/include/linux/io.h b/include/linux/io.h
index 58482241c95c..080a4fbf2ba4 100644
--- a/include/linux/io.h
+++ b/include/linux/io.h
@@ -130,6 +130,27 @@ static inline void __iomem *ioremap_uc(resource_size_t offset,
 }
 #endif
 
+static inline void __iomem *strict_ioremap_cache(resource_size_t offset,
+		unsigned long size)
+{
+#ifdef ioremap_cache
+	return ioremap_cache(offset, size);
+#else
+	return (void __force __iomem *) NULL;
+#endif
+}
+
+static inline void __iomem *strict_ioremap_wt(resource_size_t offset,
+		unsigned long size)
+{
+#ifdef ioremap_wt
+	return ioremap_wt(offset, size);
+#else
+	return (void __force __iomem *) NULL;
+#endif
+}
+
+
 /*
  * Some systems do not have legacy ISA devices.
  * /dev/port is not a valid interface on these systems.