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Subject[PATCH 4/5] devres: Add devm_ioremap_shared_resource()
Implement managed ioremap function for shared resources.

Signed-off-by: Ladislav Michl <ladis@linux-mips.org>
---
include/linux/device.h | 9 ++++++++-
lib/devres.c | 22 ++++++++++++++--------
2 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/include/linux/device.h b/include/linux/device.h
index e99d41a6190b..a35247a5f578 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -731,7 +731,14 @@ 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,
resource_size_t size);
-void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res);
+
+#define devm_ioremap_resource(dev, res) \
+ __devm_ioremap_resource(dev, res, false)
+#define devm_ioremap_shared_resource(dev, res) \
+ __devm_ioremap_resource(dev, res, true)
+
+void __iomem *__devm_ioremap_resource(struct device *dev, struct resource *res,
+ bool shared);

void devm_iounmap(struct device *dev, void __iomem *addr);

diff --git a/lib/devres.c b/lib/devres.c
index e9aad136f667..9fa15816cb83 100644
--- a/lib/devres.c
+++ b/lib/devres.c
@@ -22,6 +22,9 @@ static int devm_ioremap_match(struct device *dev, void *res, void *match_data)
* @size: Size of map
*
* Managed ioremap(). Map is automatically unmapped on driver detach.
+ *
+ * When possible, use devm_ioremap_resource() or
+ * devm_ioremap_shared_resource() instead.
*/
void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
resource_size_t size)
@@ -116,13 +119,14 @@ void devm_iounmap(struct device *dev, void __iomem *addr)
EXPORT_SYMBOL(devm_iounmap);

/**
- * devm_ioremap_resource() - check, request region, and ioremap resource
+ * __devm_ioremap_resource() - check, request region, and ioremap resource
* @dev: generic device to handle the resource for
* @res: resource to be handled
+ * @shared: region is not requested when true
*
- * Checks that a resource is a valid memory region, requests the memory
- * region and ioremaps it. All operations are managed and will be undone
- * on driver detach.
+ * Checks that a resource is a valid memory region, eventually requests the
+ * memory region and ioremaps it. All operations are managed and will be
+ * undone on driver detach.
*
* Returns a pointer to the remapped memory or an ERR_PTR() encoded error code
* on failure. Usage example:
@@ -132,7 +136,8 @@ EXPORT_SYMBOL(devm_iounmap);
* if (IS_ERR(base))
* return PTR_ERR(base);
*/
-void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res)
+void __iomem *__devm_ioremap_resource(struct device *dev, struct resource *res,
+ bool shared)
{
resource_size_t size;
const char *name;
@@ -148,7 +153,7 @@ void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res)
size = resource_size(res);
name = res->name ?: dev_name(dev);

- if (!devm_request_mem_region(dev, res->start, size, name)) {
+ if (!shared && !devm_request_mem_region(dev, res->start, size, name)) {
dev_err(dev, "can't request region for resource %pR\n", res);
return IOMEM_ERR_PTR(-EBUSY);
}
@@ -156,13 +161,14 @@ void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res)
dest_ptr = devm_ioremap(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);
+ if (!shared)
+ devm_release_mem_region(dev, res->start, size);
dest_ptr = IOMEM_ERR_PTR(-ENOMEM);
}

return dest_ptr;
}
-EXPORT_SYMBOL(devm_ioremap_resource);
+EXPORT_SYMBOL(__devm_ioremap_resource);

#ifdef CONFIG_HAS_IOPORT_MAP
/*
--
2.15.1
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