devres: add devm_memremap

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/include/linux/io.h b/include/linux/io.h
index 3fcf625..d8d749a 100644 (file)
--- a/include/linux/io.h
+++ b/include/linux/io.h
@@ -80,6 +80,10 @@ int check_signature(const volatile void __iomem *io_addr,
                        const unsigned char *signature, int length);
 void devm_ioremap_release(struct device *dev, void *res);
 
+void *devm_memremap(struct device *dev, resource_size_t offset,
+               size_t size, unsigned long flags);
+void devm_memunmap(struct device *dev, void *addr);
+
 /*
  * Some systems do not have legacy ISA devices.
  * /dev/port is not a valid interface on these systems.

diff --git a/kernel/memremap.c b/kernel/memremap.c
index a293de5..5c9b55e 100644 (file)
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -10,6 +10,7 @@
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * General Public License for more details.
  */
+#include <linux/device.h>
 #include <linux/types.h>
 #include <linux/io.h>
 #include <linux/mm.h>
@@ -96,3 +97,41 @@ void memunmap(void *addr)
                iounmap((void __iomem *) addr);
 }
 EXPORT_SYMBOL(memunmap);
+
+static void devm_memremap_release(struct device *dev, void *res)
+{
+       memunmap(res);
+}
+
+static int devm_memremap_match(struct device *dev, void *res, void *match_data)
+{
+       return *(void **)res == match_data;
+}
+
+void *devm_memremap(struct device *dev, resource_size_t offset,
+               size_t size, unsigned long flags)
+{
+       void **ptr, *addr;
+
+       ptr = devres_alloc(devm_memremap_release, sizeof(*ptr), GFP_KERNEL);
+       if (!ptr)
+               return NULL;
+
+       addr = memremap(offset, size, flags);
+       if (addr) {
+               *ptr = addr;
+               devres_add(dev, ptr);
+       } else
+               devres_free(ptr);
+
+       return addr;
+}
+EXPORT_SYMBOL(devm_memremap);
+
+void devm_memunmap(struct device *dev, void *addr)
+{
+       WARN_ON(devres_destroy(dev, devm_memremap_release, devm_memremap_match,
+                              addr));
+       memunmap(addr);
+}
+EXPORT_SYMBOL(devm_memunmap);