omap2+: add drm device

[pandora-kernel.git] / mm / internal.h

diff --git a/mm/internal.h b/mm/internal.h
index d071d38..c444510 100644 (file)
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -37,6 +37,52 @@ static inline void __put_page(struct page *page)
        atomic_dec(&page->_count);
 }
 
+static inline void __get_page_tail_foll(struct page *page,
+                                       bool get_page_head)
+{
+       /*
+        * If we're getting a tail page, the elevated page->_count is
+        * required only in the head page and we will elevate the head
+        * page->_count and tail page->_mapcount.
+        *
+        * We elevate page_tail->_mapcount for tail pages to force
+        * page_tail->_count to be zero at all times to avoid getting
+        * false positives from get_page_unless_zero() with
+        * speculative page access (like in
+        * page_cache_get_speculative()) on tail pages.
+        */
+       VM_BUG_ON(atomic_read(&page->first_page->_count) <= 0);
+       VM_BUG_ON(atomic_read(&page->_count) != 0);
+       VM_BUG_ON(page_mapcount(page) < 0);
+       if (get_page_head)
+               atomic_inc(&page->first_page->_count);
+       atomic_inc(&page->_mapcount);
+}
+
+/*
+ * This is meant to be called as the FOLL_GET operation of
+ * follow_page() and it must be called while holding the proper PT
+ * lock while the pte (or pmd_trans_huge) is still mapping the page.
+ */
+static inline void get_page_foll(struct page *page)
+{
+       if (unlikely(PageTail(page)))
+               /*
+                * This is safe only because
+                * __split_huge_page_refcount() can't run under
+                * get_page_foll() because we hold the proper PT lock.
+                */
+               __get_page_tail_foll(page, true);
+       else {
+               /*
+                * Getting a normal page or the head of a compound page
+                * requires to already have an elevated page->_count.
+                */
+               VM_BUG_ON(atomic_read(&page->_count) <= 0);
+               atomic_inc(&page->_count);
+       }
+}
+
 extern unsigned long highest_memmap_pfn;
 
 /*
@@ -54,6 +100,39 @@ extern void prep_compound_page(struct page *page, unsigned long order);
 extern bool is_free_buddy_page(struct page *page);
 #endif
 
+#if defined CONFIG_COMPACTION || defined CONFIG_CMA
+
+/*
+ * in mm/compaction.c
+ */
+/*
+ * compact_control is used to track pages being migrated and the free pages
+ * they are being migrated to during memory compaction. The free_pfn starts
+ * at the end of a zone and migrate_pfn begins at the start. Movable pages
+ * are moved to the end of a zone during a compaction run and the run
+ * completes when free_pfn <= migrate_pfn
+ */
+struct compact_control {
+       struct list_head freepages;     /* List of free pages to migrate to */
+       struct list_head migratepages;  /* List of pages being migrated */
+       unsigned long nr_freepages;     /* Number of isolated free pages */
+       unsigned long nr_migratepages;  /* Number of pages to migrate */
+       unsigned long free_pfn;         /* isolate_freepages search base */
+       unsigned long migrate_pfn;      /* isolate_migratepages search base */
+       bool sync;                      /* Synchronous migration */
+
+       unsigned int order;             /* order a direct compactor needs */
+       int migratetype;                /* MOVABLE, RECLAIMABLE etc */
+       struct zone *zone;
+};
+
+unsigned long
+isolate_freepages_range(unsigned long start_pfn, unsigned long end_pfn);
+unsigned long
+isolate_migratepages_range(struct zone *zone, struct compact_control *cc,
+                          unsigned long low_pfn, unsigned long end_pfn);
+
+#endif
 
 /*
  * function for dealing with page's order in buddy system.
@@ -263,3 +342,5 @@ extern u64 hwpoison_filter_flags_mask;
 extern u64 hwpoison_filter_flags_value;
 extern u64 hwpoison_filter_memcg;
 extern u32 hwpoison_filter_enable;
+
+extern void set_pageblock_order(void);