From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
Make hmm_data an explicit member of the struct page union.
Signed-off-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
---
include/linux/hmm.h | 8 ++------
include/linux/mm_types.h | 12 ++++++------
2 files changed, 8 insertions(+), 12 deletions(-)
diff --git a/include/linux/hmm.h b/include/linux/hmm.h
index 39988924de3a..91c1b2dccbbb 100644
--- a/include/linux/hmm.h
+++ b/include/linux/hmm.h
@@ -522,9 +522,7 @@ void hmm_devmem_remove(struct hmm_devmem *devmem);
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 void hmm_devmem_page_set_drvdata(struct page *page,
*/
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 7eb7092424b7..530a9a2b039b 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -146,15 +146,15 @@ struct page {
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. */
--
2.17.0
