Purge cache command

Purge invalidates all cache lines. It is very usefull feature for tests.

Calling purge is possbile with casadm `--script` swtich.

Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>

modules/include/cas_ioctl_codes.h

@@ -410,6 +410,7 @@ struct kcas_get_cache_param {
  *    32    *    KCAS_IOCTL_SET_CACHE_PARAM                 *    OK            *
  *    33    *    KCAS_IOCTL_GET_CACHE_PARAM                 *    OK            *
  *    34    *    KCAS_IOCTL_GET_STATS                       *    OK            *
+ *    35    *    KCAS_IOCTL_PURGE_CACHE                     *    OK            *
  *******************************************************************************
  */
 
@@ -500,6 +501,10 @@ struct kcas_get_cache_param {
 /** Get stats of particular OCF object */
 #define KCAS_IOCTL_GET_STATS _IOR(KCAS_IOCTL_MAGIC, 34, struct kcas_get_stats)
 
+/* Flush dirty data from running cache
+ * and invalidate all valid cache lines */
+#define KCAS_IOCTL_PURGE_CACHE _IOWR(KCAS_IOCTL_MAGIC, 35, struct kcas_flush_cache)
+
 /**
  * Extended kernel CAS error codes
  */