Cscope plugin for vim is really awesome. Linux kernel has the special make option to build the cscope.out files. Just do “make cscope” and the file will be created. For me the only problem was that if i ever want to do browsing the linux kernel code, I had to go to the directory where the cscope.out file is present, but not now.
Following line in the .vimrc will allow you to open any file from any location, and you will be able to use the ctags/cscope in that file.
cscope add /usr/src/linux/cscope.out /usr/src/linux
life is good.