xen: don't use page->lru for ZONE_DEVICE memory

[linux-2.6-microblaze.git] / drivers / xen / grant-table.c

diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index e2e4291..3729bea 100644 (file)
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -813,10 +813,63 @@ int gnttab_alloc_pages(int nr_pages, struct page **pages)
 }
 EXPORT_SYMBOL_GPL(gnttab_alloc_pages);
 
+#ifdef CONFIG_XEN_UNPOPULATED_ALLOC
+static inline void cache_init(struct gnttab_page_cache *cache)
+{
+       cache->pages = NULL;
+}
+
+static inline bool cache_empty(struct gnttab_page_cache *cache)
+{
+       return !cache->pages;
+}
+
+static inline struct page *cache_deq(struct gnttab_page_cache *cache)
+{
+       struct page *page;
+
+       page = cache->pages;
+       cache->pages = page->zone_device_data;
+
+       return page;
+}
+
+static inline void cache_enq(struct gnttab_page_cache *cache, struct page *page)
+{
+       page->zone_device_data = cache->pages;
+       cache->pages = page;
+}
+#else
+static inline void cache_init(struct gnttab_page_cache *cache)
+{
+       INIT_LIST_HEAD(&cache->pages);
+}
+
+static inline bool cache_empty(struct gnttab_page_cache *cache)
+{
+       return list_empty(&cache->pages);
+}
+
+static inline struct page *cache_deq(struct gnttab_page_cache *cache)
+{
+       struct page *page;
+
+       page = list_first_entry(&cache->pages, struct page, lru);
+       list_del(&page->lru);
+
+       return page;
+}
+
+static inline void cache_enq(struct gnttab_page_cache *cache, struct page *page)
+{
+       list_add(&page->lru, &cache->pages);
+}
+#endif
+
 void gnttab_page_cache_init(struct gnttab_page_cache *cache)
 {
        spin_lock_init(&cache->lock);
-       INIT_LIST_HEAD(&cache->pages);
+       cache_init(cache);
        cache->num_pages = 0;
 }
 EXPORT_SYMBOL_GPL(gnttab_page_cache_init);
@@ -827,13 +880,12 @@ int gnttab_page_cache_get(struct gnttab_page_cache *cache, struct page **page)
 
        spin_lock_irqsave(&cache->lock, flags);
 
-       if (list_empty(&cache->pages)) {
+       if (cache_empty(cache)) {
                spin_unlock_irqrestore(&cache->lock, flags);
                return gnttab_alloc_pages(1, page);
        }
 
-       page[0] = list_first_entry(&cache->pages, struct page, lru);
-       list_del(&page[0]->lru);
+       page[0] = cache_deq(cache);
        cache->num_pages--;
 
        spin_unlock_irqrestore(&cache->lock, flags);
@@ -851,7 +903,7 @@ void gnttab_page_cache_put(struct gnttab_page_cache *cache, struct page **page,
        spin_lock_irqsave(&cache->lock, flags);
 
        for (i = 0; i < num; i++)
-               list_add(&page[i]->lru, &cache->pages);
+               cache_enq(cache, page[i]);
        cache->num_pages += num;
 
        spin_unlock_irqrestore(&cache->lock, flags);
@@ -867,8 +919,7 @@ void gnttab_page_cache_shrink(struct gnttab_page_cache *cache, unsigned int num)
        spin_lock_irqsave(&cache->lock, flags);
 
        while (cache->num_pages > num) {
-               page[i] = list_first_entry(&cache->pages, struct page, lru);
-               list_del(&page[i]->lru);
+               page[i] = cache_deq(cache);
                cache->num_pages--;
                if (++i == ARRAY_SIZE(page)) {
                        spin_unlock_irqrestore(&cache->lock, flags);