Re: [PATCH v2] of/address: Add of_iomap_nocache

From: Scott Wood
Date: Thu Aug 04 2011 - 12:56:42 EST


On 08/04/2011 05:36 AM, David Brown wrote:
Add uncached mappings from devicetree nodes similar to regular io
mappings.

SPARC is coherent, so there this call is the same as regular of_iomap.

Cc: David Miller<davem@xxxxxxxxxxxxx>
Signed-off-by: David Brown<davidb@xxxxxxxxxxxxxx>
---
v2 - Add implementation for SPARC

drivers/of/address.c | 19 +++++++++++++++++++
include/linux/of_address.h | 10 ++++++++++
2 files changed, 29 insertions(+), 0 deletions(-)

diff --git a/drivers/of/address.c b/drivers/of/address.c
index 72c33fb..9bee7f8 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -613,3 +613,22 @@ void __iomem *of_iomap(struct device_node *np, int index)
return ioremap(res.start, resource_size(&res));
}
EXPORT_SYMBOL(of_iomap);
+
+/**
+ * of_iomap_nocache - Maps the memory mapped IO for a given
+ * device_node, using ioremap_nocache.
+ * @device: the device whose io range will be mapped
+ * @index: index of the io range
+ *
+ * Returns a pointer to the mapped memory
+ */
+void __iomem *of_iomap_nocache(struct device_node *np, int index)
+{
+ struct resource res;
+
+ if (of_address_to_resource(np, index,&res))
+ return NULL;
+
+ return ioremap_nocache(res.start, 1 + res.end - res.start);
+}

resource_size()?

+EXPORT_SYMBOL(of_iomap_nocache);
diff --git a/include/linux/of_address.h b/include/linux/of_address.h
index 3118623..0e4734b 100644
--- a/include/linux/of_address.h
+++ b/include/linux/of_address.h
@@ -13,6 +13,16 @@ extern struct device_node *of_find_matching_node_by_address(
u64 base_address);
extern void __iomem *of_iomap(struct device_node *device, int index);

+#ifndef SPARC
+extern void __iomem *of_iomap_nocache(struct device_node *device, int index);
+#else
+static inline void __iomem *of_iomap_nocache(struct device_node *device,
+ int index)
+{
+ return of_iomap(device, index);
+}
+#endif

Why is sparc special? It looks like it defines ioremap_nocache() as ioremap() just like powerpc and some others, so shouldn't the normal of_iomap_nocache just work?

-Scott

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