[PATCH 2/12] devres: implement managed IO region interface

From: Tejun Heo
Date: Tue Dec 26 2006 - 10:20:55 EST


Implement managed IO region interface - devm_request_region() and
devm_release_region(). Except for the first @dev argument and being
managed, these take the same arguments and have the same effect as
non-managed coutnerparts.

Signed-off-by: Tejun Heo <htejun@xxxxxxxxx>
---
include/linux/ioport.h | 20 +++++++++++++++
kernel/resource.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 82 insertions(+), 0 deletions(-)

diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index 15228d7..6859a3b 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -137,4 +137,24 @@ static inline int __deprecated check_region(resource_size_t s,
{
return __check_region(&ioport_resource, s, n);
}
+
+/* Wrappers for managed devices */
+struct device;
+#define devm_request_region(dev,start,n,name) \
+ __devm_request_region(dev, &ioport_resource, (start), (n), (name))
+#define devm_request_mem_region(dev,start,n,name) \
+ __devm_request_region(dev, &iomem_resource, (start), (n), (name))
+
+extern struct resource * __devm_request_region(struct device *dev,
+ struct resource *parent, resource_size_t start,
+ resource_size_t n, const char *name);
+
+#define devm_release_region(start,n) \
+ __devm_release_region(dev, &ioport_resource, (start), (n))
+#define devm_release_mem_region(start,n) \
+ __devm_release_region(dev, &iomem_resource, (start), (n))
+
+extern void __devm_release_region(struct device *dev, struct resource *parent,
+ resource_size_t start, resource_size_t n);
+
#endif /* _LINUX_IOPORT_H */
diff --git a/kernel/resource.c b/kernel/resource.c
index 7b9a497..2a3f886 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -17,6 +17,7 @@
#include <linux/fs.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
+#include <linux/device.h>
#include <asm/io.h>


@@ -618,6 +619,67 @@ void __release_region(struct resource *parent, resource_size_t start,
EXPORT_SYMBOL(__release_region);

/*
+ * Managed region resource
+ */
+struct region_devres {
+ struct resource *parent;
+ resource_size_t start;
+ resource_size_t n;
+};
+
+static void devm_region_release(struct device *dev, void *res)
+{
+ struct region_devres *this = res;
+
+ __release_region(this->parent, this->start, this->n);
+}
+
+static int devm_region_match(struct device *dev, void *res, void *match_data)
+{
+ struct region_devres *this = res, *match = match_data;
+
+ return this->parent == match->parent &&
+ this->start == match->start && this->n == match->n;
+}
+
+struct resource * __devm_request_region(struct device *dev,
+ struct resource *parent, resource_size_t start,
+ resource_size_t n, const char *name)
+{
+ struct region_devres *dr = NULL;
+ struct resource *res;
+
+ dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
+ GFP_KERNEL);
+ if (!dr)
+ return NULL;
+
+ dr->parent = parent;
+ dr->start = start;
+ dr->n = n;
+
+ res = __request_region(parent, start, n, name);
+ if (res)
+ devres_add(dev, dr);
+ else
+ devres_free(dr);
+
+ return res;
+}
+EXPORT_SYMBOL(__devm_request_region);
+
+void __devm_release_region(struct device *dev, struct resource *parent,
+ resource_size_t start, resource_size_t n)
+{
+ struct region_devres match_data = { parent, start, n };
+
+ __release_region(parent, start, n);
+ WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
+ &match_data));
+}
+EXPORT_SYMBOL(__devm_release_region);
+
+/*
* Called from init/main.c to reserve IO ports.
*/
#define MAXRESERVE 4
--
1.4.4.2


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