Kernal <-> Block Driver <-> Storage Device

[Nav Mundi]

Scenario:
1) Interupt requests from Kernal to read information.
2) Kernel asks block driver to fetch some information from the storage device
3) The block driver fetchs this information and stores it in the DMA
4) The storage device then interupts the Kernal OR Driver to signal that it 
is finished reading. 

Questions:
1) In step 4), does the storage device interupt the Kernal or the Driver when 
it is finished reading information to the DMA?  
2) If the Kernal is interrupted what does the Kernel do then?  
3) If the Block Driver is interrupted, what does the Driver do then?
4) Where is the code located for Questions 1) -> 3)

Please advise. Thanks.
-Nav