mm/devm_memremap_pages: introduce devm_memunmap_pages

Use the new devm_release_action() facility to allow
devm_memremap_pages_release() to be manually triggered.

Link: http://lkml.kernel.org/r/155727337088.292046.5774214552136776763.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/memremap.h b/include/linux/memremap.h
index f062866..7601ee3 100644 (file)
--- a/include/linux/memremap.h
+++ b/include/linux/memremap.h
@@ -100,6 +100,7 @@ struct dev_pagemap {
 
 #ifdef CONFIG_ZONE_DEVICE
 void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap);
+void devm_memunmap_pages(struct device *dev, struct dev_pagemap *pgmap);
 struct dev_pagemap *get_dev_pagemap(unsigned long pfn,
                struct dev_pagemap *pgmap);
 
@@ -118,6 +119,11 @@ static inline void *devm_memremap_pages(struct device *dev,
        return ERR_PTR(-ENXIO);
 }
 
+static inline void devm_memunmap_pages(struct device *dev,
+               struct dev_pagemap *pgmap)
+{
+}
+
 static inline struct dev_pagemap *get_dev_pagemap(unsigned long pfn,
                struct dev_pagemap *pgmap)
 {

diff --git a/kernel/memremap.c b/kernel/memremap.c
index 1490e63..715b434 100644 (file)
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -271,6 +271,12 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
 }
 EXPORT_SYMBOL_GPL(devm_memremap_pages);
 
+void devm_memunmap_pages(struct device *dev, struct dev_pagemap *pgmap)
+{
+       devm_release_action(dev, devm_memremap_pages_release, pgmap);
+}
+EXPORT_SYMBOL_GPL(devm_memunmap_pages);
+
 unsigned long vmem_altmap_offset(struct vmem_altmap *altmap)
 {
        /* number of pfns from base where pfn_to_page() is valid */