[PATCH v11 09/17] rangeset: add rangeset_empty() function

[Volodymyr Babchuk <Volodymyr_Babchuk@xxxxxxxx>]

This function can be used when user wants to remove all rangeset
entries but do not want to destroy rangeset itself.

Signed-off-by: Volodymyr Babchuk <volodymyr_babchuk@xxxxxxxx>

---
Changes in v11:
 - Now the function only empties rangeset, without removing it from
   domain's list

Changes in v10:
 - New in v10. The function is used in "vpci/header: handle p2m range sets per 
BAR"
---
 xen/common/rangeset.c      | 16 ++++++++++++----
 xen/include/xen/rangeset.h |  3 ++-
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/xen/common/rangeset.c b/xen/common/rangeset.c
index 0ccd53caac..d0c525cb50 100644
--- a/xen/common/rangeset.c
+++ b/xen/common/rangeset.c
@@ -448,11 +448,20 @@ struct rangeset *rangeset_new(
     return r;
 }
 
-void rangeset_destroy(
-    struct rangeset *r)
+void rangeset_empty(struct rangeset *r)
 {
     struct range *x;
 
+    if ( r == NULL )
+        return;
+
+    while ( (x = first_range(r)) != NULL )
+        destroy_range(r, x);
+}
+
+void rangeset_destroy(
+    struct rangeset *r)
+{
     if ( r == NULL )
         return;
 
@@ -463,8 +472,7 @@ void rangeset_destroy(
         spin_unlock(&r->domain->rangesets_lock);
     }
 
-    while ( (x = first_range(r)) != NULL )
-        destroy_range(r, x);
+    rangeset_empty(r);
 
     xfree(r);
 }
diff --git a/xen/include/xen/rangeset.h b/xen/include/xen/rangeset.h
index 87bd956962..62cb67b49b 100644
--- a/xen/include/xen/rangeset.h
+++ b/xen/include/xen/rangeset.h
@@ -56,7 +56,7 @@ void rangeset_limit(
 bool __must_check rangeset_is_empty(
     const struct rangeset *r);
 
-/* Add/claim/remove/query a numeric range. */
+/* Add/claim/remove/query/empty a numeric range. */
 int __must_check rangeset_add_range(
     struct rangeset *r, unsigned long s, unsigned long e);
 int __must_check rangeset_claim_range(struct rangeset *r, unsigned long size,
@@ -70,6 +70,7 @@ bool __must_check rangeset_overlaps_range(
 int rangeset_report_ranges(
     struct rangeset *r, unsigned long s, unsigned long e,
     int (*cb)(unsigned long s, unsigned long e, void *data), void *ctxt);
+void rangeset_empty(struct rangeset *r);
 
 /*
  * Note that the consume function can return an error value apart from
-- 
2.42.0