This function allows to iterate over a rangeset while removing the
processed regions.
This will be used in order to split processing of large memory areas
when mapping them into the guest p2m.
Signed-off-by: Roger Pau Monné <roger....@citrix.com>
Reviewed-by: Wei Liu <wei.l...@citrix.com>
---
Cc: Andrew Cooper <andrew.coop...@citrix.com>
Cc: George Dunlap <george.dun...@eu.citrix.com>
Cc: Ian Jackson <ian.jack...@eu.citrix.com>
Cc: Jan Beulich <jbeul...@suse.com>
Cc: Julien Grall <julien.gr...@arm.com>
Cc: Konrad Rzeszutek Wilk <konrad.w...@oracle.com>
Cc: Stefano Stabellini <sstabell...@kernel.org>
Cc: Tim Deegan <t...@xen.org>
Cc: Wei Liu <wei.l...@citrix.com>
---
Changes since v6:
- Expand commit message.
- Add a comment to describe the expected function behavior.
- Fix indentation.
Changes since v5:
- New in this version.
---
xen/common/rangeset.c | 28 ++++++++++++++++++++++++++++
xen/include/xen/rangeset.h | 10 ++++++++++
2 files changed, 38 insertions(+)
diff --git a/xen/common/rangeset.c b/xen/common/rangeset.c
index ade34f6a50..bb68ce62e4 100644
--- a/xen/common/rangeset.c
+++ b/xen/common/rangeset.c
@@ -350,6 +350,34 @@ int rangeset_claim_range(struct rangeset *r, unsigned long
size,
return 0;
}
+int rangeset_consume_ranges(struct rangeset *r,
+ int (*cb)(unsigned long s, unsigned long e, void *,
+ unsigned long *c),
+ void *ctxt)
+{
+ int rc = 0;
+
+ write_lock(&r->lock);
+ while ( !rangeset_is_empty(r) )
+ {
+ unsigned long consumed = 0;
+ struct range *x = first_range(r);
+
+ rc = cb(x->s, x->e, ctxt, &consumed);
+
+ ASSERT(consumed <= x->e - x->s + 1);
+ x->s += consumed;
+ if ( x->s > x->e )
+ destroy_range(r, x);
+
+ if ( rc )
+ break;
+ }
+ write_unlock(&r->lock);
+
+ return rc;
+}
+
int rangeset_add_singleton(
struct rangeset *r, unsigned long s)
{
diff --git a/xen/include/xen/rangeset.h b/xen/include/xen/rangeset.h
index 1f83b1f44b..583b72bb0c 100644
--- a/xen/include/xen/rangeset.h
+++ b/xen/include/xen/rangeset.h
@@ -70,6 +70,16 @@ int rangeset_report_ranges(
struct rangeset *r, unsigned long s, unsigned long e,
int (*cb)(unsigned long s, unsigned long e, void *), void *ctxt);
+/*
+ * Note that the consume function can return an error value apart from
+ * -ERESTART, and that no cleanup is performed (ie: the user should call
+ * rangeset_destroy if needed).
+ */
+int rangeset_consume_ranges(struct rangeset *r,
+ int (*cb)(unsigned long s, unsigned long e,
+ void *, unsigned long *c),
+ void *ctxt);
+
/* Add/remove/query a single number. */
int __must_check rangeset_add_singleton(
struct rangeset *r, unsigned long s);
--
2.16.2
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