xen/grant-table: add helpers for allocating pages
Add gnttab_alloc_pages() and gnttab_free_pages() to allocate/free pages
suitable to for granted maps.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 6444172..8cc3f06 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -119,7 +119,7 @@
return;
if (map->pages)
- free_xenballooned_pages(map->count, map->pages);
+ gnttab_free_pages(map->count, map->pages);
kfree(map->pages);
kfree(map->grants);
kfree(map->map_ops);
@@ -152,7 +152,7 @@
NULL == add->pages)
goto err;
- if (alloc_xenballooned_pages(count, add->pages, false /* lowmem */))
+ if (gnttab_alloc_pages(count, add->pages))
goto err;
for (i = 0; i < count; i++) {
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index 999d7ab..b4f93c4 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -50,6 +50,7 @@
#include <xen/interface/memory.h>
#include <xen/hvc-console.h>
#include <xen/swiotlb-xen.h>
+#include <xen/balloon.h>
#include <asm/xen/hypercall.h>
#include <asm/xen/interface.h>
@@ -671,6 +672,34 @@
}
EXPORT_SYMBOL_GPL(gnttab_free_auto_xlat_frames);
+/**
+ * gnttab_alloc_pages - alloc pages suitable for grant mapping into
+ * @nr_pages: number of pages to alloc
+ * @pages: returns the pages
+ */
+int gnttab_alloc_pages(int nr_pages, struct page **pages)
+{
+ int ret;
+
+ ret = alloc_xenballooned_pages(nr_pages, pages, false);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+EXPORT_SYMBOL(gnttab_alloc_pages);
+
+/**
+ * gnttab_free_pages - free pages allocated by gnttab_alloc_pages()
+ * @nr_pages; number of pages to free
+ * @pages: the pages
+ */
+void gnttab_free_pages(int nr_pages, struct page **pages)
+{
+ free_xenballooned_pages(nr_pages, pages);
+}
+EXPORT_SYMBOL(gnttab_free_pages);
+
/* Handling of paged out grant targets (GNTST_eagain) */
#define MAX_DELAY 256
static inline void
diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c
index e999496e..ecd540a 100644
--- a/drivers/xen/xen-scsiback.c
+++ b/drivers/xen/xen-scsiback.c
@@ -227,7 +227,7 @@
return;
if (i > scsiback_max_buffer_pages) {
n = min(num, i - scsiback_max_buffer_pages);
- free_xenballooned_pages(n, page + num - n);
+ gnttab_free_pages(n, page + num - n);
n = num - n;
}
spin_lock_irqsave(&free_pages_lock, flags);
@@ -244,7 +244,7 @@
spin_lock_irqsave(&free_pages_lock, flags);
if (list_empty(&scsiback_free_pages)) {
spin_unlock_irqrestore(&free_pages_lock, flags);
- return alloc_xenballooned_pages(1, page, false);
+ return gnttab_alloc_pages(1, page);
}
page[0] = list_first_entry(&scsiback_free_pages, struct page, lru);
list_del(&page[0]->lru);
@@ -2106,7 +2106,7 @@
while (free_pages_num) {
if (get_free_page(&page))
BUG();
- free_xenballooned_pages(1, &page);
+ gnttab_free_pages(1, &page);
}
scsiback_deregister_configfs();
xenbus_unregister_driver(&scsiback_driver);
