mm: add hmm_data to struct page
Make hmm_data an explicit member of the struct page union.
Link: http://lkml.kernel.org/r/20180518194519.3820-14-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/hmm.h b/include/linux/hmm.h
index 2f1327c..4c92e3b 100644
--- a/include/linux/hmm.h
+++ b/include/linux/hmm.h
@@ -522,9 +522,7 @@
static inline void hmm_devmem_page_set_drvdata(struct page *page,
unsigned long data)
{
- unsigned long *drvdata = (unsigned long *)&page->pgmap;
-
- drvdata[1] = data;
+ page->hmm_data = data;
}
/*
@@ -535,9 +533,7 @@
*/
static inline unsigned long hmm_devmem_page_get_drvdata(const struct page *page)
{
- const unsigned long *drvdata = (const unsigned long *)&page->pgmap;
-
- return drvdata[1];
+ return page->hmm_data;
}
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 811aa0c..99ce070 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -146,15 +146,15 @@
spinlock_t ptl;
#endif
};
+ struct { /* ZONE_DEVICE pages */
+ /** @pgmap: Points to the hosting device page map. */
+ struct dev_pagemap *pgmap;
+ unsigned long hmm_data;
+ unsigned long _zd_pad_1; /* uses mapping */
+ };
/** @rcu_head: You can use this to free a page by RCU. */
struct rcu_head rcu_head;
-
- /**
- * @pgmap: For ZONE_DEVICE pages, this points to the hosting
- * device page map.
- */
- struct dev_pagemap *pgmap;
};
union { /* This union is 4 bytes in size. */