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path: root/drivers/s390/cio/idset.c
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Diffstat (limited to 'drivers/s390/cio/idset.c')
-rw-r--r--drivers/s390/cio/idset.c112
1 files changed, 112 insertions, 0 deletions
diff --git a/drivers/s390/cio/idset.c b/drivers/s390/cio/idset.c
new file mode 100644
index 000000000000..16ea828e99f7
--- /dev/null
+++ b/drivers/s390/cio/idset.c
@@ -0,0 +1,112 @@
+/*
+ * drivers/s390/cio/idset.c
+ *
+ * Copyright IBM Corp. 2007
+ * Author(s): Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
+ */
+
+#include <linux/slab.h>
+#include <asm/bitops.h>
+#include "idset.h"
+#include "css.h"
+
+struct idset {
+ int num_ssid;
+ int num_id;
+ unsigned long bitmap[0];
+};
+
+static inline unsigned long bitmap_size(int num_ssid, int num_id)
+{
+ return __BITOPS_WORDS(num_ssid * num_id) * sizeof(unsigned long);
+}
+
+static struct idset *idset_new(int num_ssid, int num_id)
+{
+ struct idset *set;
+
+ set = kzalloc(sizeof(struct idset) + bitmap_size(num_ssid, num_id),
+ GFP_KERNEL);
+ if (set) {
+ set->num_ssid = num_ssid;
+ set->num_id = num_id;
+ }
+ return set;
+}
+
+void idset_free(struct idset *set)
+{
+ kfree(set);
+}
+
+void idset_clear(struct idset *set)
+{
+ memset(set->bitmap, 0, bitmap_size(set->num_ssid, set->num_id));
+}
+
+void idset_fill(struct idset *set)
+{
+ memset(set->bitmap, 0xff, bitmap_size(set->num_ssid, set->num_id));
+}
+
+static inline void idset_add(struct idset *set, int ssid, int id)
+{
+ set_bit(ssid * set->num_id + id, set->bitmap);
+}
+
+static inline void idset_del(struct idset *set, int ssid, int id)
+{
+ clear_bit(ssid * set->num_id + id, set->bitmap);
+}
+
+static inline int idset_contains(struct idset *set, int ssid, int id)
+{
+ return test_bit(ssid * set->num_id + id, set->bitmap);
+}
+
+static inline int idset_get_first(struct idset *set, int *ssid, int *id)
+{
+ int bitnum;
+
+ bitnum = find_first_bit(set->bitmap, set->num_ssid * set->num_id);
+ if (bitnum >= set->num_ssid * set->num_id)
+ return 0;
+ *ssid = bitnum / set->num_id;
+ *id = bitnum % set->num_id;
+ return 1;
+}
+
+struct idset *idset_sch_new(void)
+{
+ return idset_new(__MAX_SSID + 1, __MAX_SUBCHANNEL + 1);
+}
+
+void idset_sch_add(struct idset *set, struct subchannel_id schid)
+{
+ idset_add(set, schid.ssid, schid.sch_no);
+}
+
+void idset_sch_del(struct idset *set, struct subchannel_id schid)
+{
+ idset_del(set, schid.ssid, schid.sch_no);
+}
+
+int idset_sch_contains(struct idset *set, struct subchannel_id schid)
+{
+ return idset_contains(set, schid.ssid, schid.sch_no);
+}
+
+int idset_sch_get_first(struct idset *set, struct subchannel_id *schid)
+{
+ int ssid = 0;
+ int id = 0;
+ int rc;
+
+ rc = idset_get_first(set, &ssid, &id);
+ if (rc) {
+ init_subchannel_id(schid);
+ schid->ssid = ssid;
+ schid->sch_no = id;
+ }
+ return rc;
+}