drivers/ieee1394/guid.h

   1
   2 #ifndef _IEEE1394_GUID_H
   3 #define _IEEE1394_GUID_H
   4
   5
   6 /*
   7  * General information: Finding out which GUID belongs to which node is done by
   8  * sending packets and therefore waiting for the answers.  Wherever it is
   9  * mentioned that a node is inaccessible this could just as well mean that we
  10  * just don't know yet (usually, bus reset handlers can't rely on GUIDs being
  11  * associated with current nodes).
  12  */
  13
  14 struct guid_entry;
  15 typedef struct guid_entry *hpsb_guid_t;
  16
  17
  18 /*
  19  * Returns a guid handle (which has its reference count incremented) or NULL if
  20  * there is the GUID in question is not known of.  Getting a valid handle does
  21  * not mean that the node with this GUID is currently accessible (might not be
  22  * plugged in or powered down).
  23  */
  24 hpsb_guid_t hpsb_guid_get_handle(u64 guid);
  25
  26 /*
  27  * If the handle refers to a local host, this function will return the pointer
  28  * to the hpsb_host structure.  It will return NULL otherwise.  Once you have
  29  * established it is a local host, you can use that knowledge from then on (the
  30  * GUID won't wander to an external node).
  31  *
  32  * Note that the local GUID currently isn't collected, so this will always
  33  * return NULL.
  34  */
  35 struct hpsb_host *hpsb_guid_localhost(hpsb_guid_t handle);
  36
  37 /*
  38  * This will fill in the given, pre-initialised hpsb_packet with the current
  39  * information from the GUID handle (host, node ID, generation number).  It will
  40  * return false if the node owning the GUID is not accessible (and not modify the
  41  * hpsb_packet) and return true otherwise.
  42  *
  43  * Note that packet sending may still fail in hpsb_send_packet if a bus reset
  44  * happens while you are trying to set up the packet (due to obsolete generation
  45  * number).  It will at least reliably fail so that you don't accidentally and
  46  * unknowingly send your packet to the wrong node.
  47  */
  48 int hpsb_guid_fill_packet(hpsb_guid_t handle, struct hpsb_packet *pkt);
  49
  50
  51 void init_ieee1394_guid(void);
  52
  53
  54 #endif /* _IEEE1394_GUID_H */