[PATCH v5 4/6] devm: fix ioremap_cache() usage

From: Dan Williams
Date: Mon Jun 22 2015 - 04:31:21 EST


Provide devm_ioremap_cache() and fix up devm_ioremap_resource() to
actually provide cacheable mappings. On archs that implement
ioremap_cache() devm_ioremap_resource() is always silently falling back
to uncached when IORESOURCE_CACHEABLE is specified.

Cc: Toshi Kani <toshi.kani@xxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
include/linux/io.h | 2 ++
lib/devres.c | 53 +++++++++++++++++++++++++---------------------------
2 files changed, 27 insertions(+), 28 deletions(-)

diff --git a/include/linux/io.h b/include/linux/io.h
index 41e93fe14b3c..8789a114f37c 100644
--- a/include/linux/io.h
+++ b/include/linux/io.h
@@ -71,6 +71,8 @@ static inline void devm_ioport_unmap(struct device *dev, void __iomem *addr)

void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
resource_size_t size);
+void __iomem *devm_ioremap_cache(struct device *dev, resource_size_t offset,
+ resource_size_t size);
void __iomem *devm_ioremap_nocache(struct device *dev, resource_size_t offset,
resource_size_t size);
void __iomem *devm_ioremap_wc(struct device *dev, resource_size_t offset,
diff --git a/lib/devres.c b/lib/devres.c
index f4001d90d24d..c8e75cdaf816 100644
--- a/lib/devres.c
+++ b/lib/devres.c
@@ -14,6 +14,8 @@ static int devm_ioremap_match(struct device *dev, void *res, void *match_data)
return *(void **)res == match_data;
}

+typedef void __iomem *(*ioremap_fn)(resource_size_t offset, unsigned long size);
+
/**
* devm_ioremap - Managed ioremap()
* @dev: Generic device to remap IO address for
@@ -22,8 +24,9 @@ static int devm_ioremap_match(struct device *dev, void *res, void *match_data)
*
* Managed ioremap(). Map is automatically unmapped on driver detach.
*/
-void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
- resource_size_t size)
+static void __iomem *devm_ioremap_type(struct device *dev,
+ resource_size_t offset, resource_size_t size,
+ ioremap_fn ioremap_type)
{
void __iomem **ptr, *addr;

@@ -31,7 +34,7 @@ void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
if (!ptr)
return NULL;

- addr = ioremap(offset, size);
+ addr = ioremap_type(offset, size);
if (addr) {
*ptr = addr;
devres_add(dev, ptr);
@@ -40,34 +43,25 @@ void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,

return addr;
}
+
+void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
+ resource_size_t size)
+{
+ return devm_ioremap_type(dev, offset, size, ioremap);
+}
EXPORT_SYMBOL(devm_ioremap);

-/**
- * devm_ioremap_nocache - Managed ioremap_nocache()
- * @dev: Generic device to remap IO address for
- * @offset: BUS offset to map
- * @size: Size of map
- *
- * Managed ioremap_nocache(). Map is automatically unmapped on driver
- * detach.
- */
+void __iomem *devm_ioremap_cache(struct device *dev, resource_size_t offset,
+ resource_size_t size)
+{
+ return devm_ioremap_type(dev, offset, size, ioremap_cache);
+}
+EXPORT_SYMBOL(devm_ioremap_cache);
+
void __iomem *devm_ioremap_nocache(struct device *dev, resource_size_t offset,
resource_size_t size)
{
- void __iomem **ptr, *addr;
-
- ptr = devres_alloc(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL);
- if (!ptr)
- return NULL;
-
- addr = ioremap_nocache(offset, size);
- if (addr) {
- *ptr = addr;
- devres_add(dev, ptr);
- } else
- devres_free(ptr);
-
- return addr;
+ return devm_ioremap_type(dev, offset, size, ioremap_nocache);
}
EXPORT_SYMBOL(devm_ioremap_nocache);

@@ -153,8 +147,11 @@ void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res)
return IOMEM_ERR_PTR(-EBUSY);
}

- /* FIXME: add devm_ioremap_cache support */
- dest_ptr = devm_ioremap(dev, res->start, size);
+ if (res->flags & IORESOURCE_CACHEABLE)
+ dest_ptr = devm_ioremap_cache(dev, res->start, size);
+ else
+ dest_ptr = devm_ioremap_nocache(dev, res->start, size);
+
if (!dest_ptr) {
dev_err(dev, "ioremap failed for resource %pR\n", res);
devm_release_mem_region(dev, res->start, size);

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