xen/balloon: rename alloc/free_xenballooned_pages

alloc_xenballooned_pages() and free_xenballooned_pages() are used as
direct replacements of xen_alloc_unpopulated_pages() and
xen_free_unpopulated_pages() in case CONFIG_XEN_UNPOPULATED_ALLOC isn't
defined.

Guard both functions with !CONFIG_XEN_UNPOPULATED_ALLOC and rename them
to the xen_*() variants they are replacing. This allows to remove some
ifdeffery from the xen.h header file. Adapt the prototype of the
functions to match.

Signed-off-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20211102092234.17852-1-jgross@suse.com
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

drivers/xen/balloon.c

@@ -580,7 +580,8 @@ void balloon_set_new_target(unsigned long target)
 }
 EXPORT_SYMBOL_GPL(balloon_set_new_target);
 
-static int add_ballooned_pages(int nr_pages)
+#ifndef CONFIG_XEN_UNPOPULATED_ALLOC
+static int add_ballooned_pages(unsigned int nr_pages)
 {
 	enum bp_state st;
 
@@ -608,14 +609,14 @@ static int add_ballooned_pages(int nr_pages)
 }
 
 /**
- * alloc_xenballooned_pages - get pages that have been ballooned out
+ * xen_alloc_unpopulated_pages - get pages that have been ballooned out
  * @nr_pages: Number of pages to get
  * @pages: pages returned
  * @return 0 on success, error otherwise
  */
-int alloc_xenballooned_pages(int nr_pages, struct page **pages)
+int xen_alloc_unpopulated_pages(unsigned int nr_pages, struct page **pages)
 {
-	int pgno = 0;
+	unsigned int pgno = 0;
 	struct page *page;
 	int ret;
 
@@ -650,7 +651,7 @@ int alloc_xenballooned_pages(int nr_pages, struct page **pages)
 	return 0;
  out_undo:
 	mutex_unlock(&balloon_mutex);
-	free_xenballooned_pages(pgno, pages);
+	xen_free_unpopulated_pages(pgno, pages);
 	/*
 	 * NB: free_xenballooned_pages will only subtract pgno pages, but since
 	 * target_unpopulated is incremented with nr_pages at the start we need
@@ -659,16 +660,16 @@ int alloc_xenballooned_pages(int nr_pages, struct page **pages)
 	balloon_stats.target_unpopulated -= nr_pages - pgno;
 	return ret;
 }
-EXPORT_SYMBOL(alloc_xenballooned_pages);
+EXPORT_SYMBOL(xen_alloc_unpopulated_pages);
 
 /**
- * free_xenballooned_pages - return pages retrieved with get_ballooned_pages
+ * xen_free_unpopulated_pages - return pages retrieved with get_ballooned_pages
  * @nr_pages: Number of pages
  * @pages: pages to return
  */
-void free_xenballooned_pages(int nr_pages, struct page **pages)
+void xen_free_unpopulated_pages(unsigned int nr_pages, struct page **pages)
 {
-	int i;
+	unsigned int i;
 
 	mutex_lock(&balloon_mutex);
 
@@ -685,9 +686,9 @@ void free_xenballooned_pages(int nr_pages, struct page **pages)
 
 	mutex_unlock(&balloon_mutex);
 }
-EXPORT_SYMBOL(free_xenballooned_pages);
+EXPORT_SYMBOL(xen_free_unpopulated_pages);
 
-#if defined(CONFIG_XEN_PV) && !defined(CONFIG_XEN_UNPOPULATED_ALLOC)
+#if defined(CONFIG_XEN_PV)
 static void __init balloon_add_region(unsigned long start_pfn,
 				      unsigned long pages)
 {
@@ -710,6 +711,7 @@ static void __init balloon_add_region(unsigned long start_pfn,
 	balloon_stats.total_pages += extra_pfn_end - start_pfn;
 }
 #endif
+#endif
 
 static int __init balloon_init(void)
 {

include/xen/balloon.h

@@ -26,9 +26,6 @@ extern struct balloon_stats balloon_stats;
 
 void balloon_set_new_target(unsigned long target);
 
-int alloc_xenballooned_pages(int nr_pages, struct page **pages);
-void free_xenballooned_pages(int nr_pages, struct page **pages);
-
 #ifdef CONFIG_XEN_BALLOON
 void xen_balloon_init(void);
 #else

include/xen/xen.h

@@ -52,13 +52,7 @@ bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
 extern u64 xen_saved_max_mem_size;
 #endif
 
-#ifdef CONFIG_XEN_UNPOPULATED_ALLOC
 int xen_alloc_unpopulated_pages(unsigned int nr_pages, struct page **pages);
 void xen_free_unpopulated_pages(unsigned int nr_pages, struct page **pages);
-#else
-#define xen_alloc_unpopulated_pages alloc_xenballooned_pages
-#define xen_free_unpopulated_pages free_xenballooned_pages
-#include <xen/balloon.h>
-#endif
 
 #endif	/* _XEN_XEN_H */