Computer Science 822
                               Quiz 2          Name_______________________

1. We identified a number of physical memories that were used in
   the 5515.  These included (1) Host system RAM (2) FFred Control Memory
   (3) RFred Control Memory (4) Adapter buffer memory.
   Identify by number the memory in which each of the following
   reside:

   _1__ a. The DLE tables

   _3__ b. The large free queue

   _2__ c. The transmit complete queue (TCQ)

   _2__ d. The transmit descriptor table

   _4__ e. Buffers in which segmentation and reassembly of AAL5
           frames takes place

2. For each of the following queues identify which entity: (1) the
   device driver (2) ffred (3) rfred  <<<modifies>>> the specified pointer
   during transmission and receipt of frames (i.e. ignore initialization)

   _2_ a. The tcq write pointer

   _2_ b. The packet ready queue read pointer

   _1_ c. The packet complete queue read pointer

   _1_ d. The large free queue write pointer

3. Identify which of the following states is UNDESIRABLE from the
   perspective of being able to send and receive data without delay
   or retransmission

   ___ a. Large free queue full

   _U_ b. Packet complete queue full - No additional packets can be rcvd.

   _U_ c. Transmit complete queue empty - No packets can be sent.

   ___ d. Packet ready queue empty

4. It always requires two interrupts to receive a packet.  What two general
   functions does the device driver perform at each.

   First - Schedule a DMA transfer to move the data from
           buffer ram to a Host skb








   Second - Push the SKB to the ATM layer






5. During transmit operations the driver "automagically" conveys to
   FFred the identity of the buffer that needs to be transmitted at
   the time the DMA transfer to the board is started.  How is this
   done??

   The descriptor number is stored in the (first) DLE and
   a mode bit set to specify that the number is to be written
   into the PRQ with the DLE completes










6. Describe the mechanism used to convey to the device driver the
   location of the skbuff and identity of the target vcc at the time
   a receive DMA completes.

   Both are stored in one of the driver rx_buf control structure.
   These structures are managed via 2 FIFO queues.  One for free
   structures and one for those for which DMA is active.
















7. Which of the following functions is used by the device driver
   in returning data in response to a request to read /proc/net/atm/ia5515

   a. printk                           b. write

   c. printf                         x d. sprintf


8. The function create_proc_read_entry() must be used to register a
   /proc file system service routine.  What items of information does
   it pass to the kernel?

  1 - The indenty of the read function
  2 - A word of data to be passed to the read function
  3 - The identity of the node the function is handle
        (/proc/net/atm/ia5515)