From: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>

sclp: core driver cleanup

Details:
- moved signal shutdown (quiesce) handling into a separate file
- cleanup of SCLP core driver:
  . introduced driver states instead of bits
  . introduced request retry count and retry limit
  . sclp_add_request now returns an error code if a request couldn't be started
  . introduced separate request structure for init_mask requests to simplify
    code
  . request timer is now manually checked in sclp_sync_wait because timer
    interrupts are disabled in this context
  . removed busy timer - request timer now handles both cases
  . split up sclp_start_request into __sclp_start_request and sclp_process
    queue
  . removed sclp_error_message (unused)
  . introduced sclp_check_handler function to split up initial init mask
    test from standard init mask request processing
  . introduced sclp_deactivate and sclp_reactivate for simplified reboot
    event handling (and potential use in suspend/resume scenario)
  . added protection against multiple concurrent init mask calls
- minor changes in SCLP core driver:
  . updated comments
  . renamed functions to be consistent with "function name starts with __ =>
    needs lock"
  . renamed internal functions for consistency reasons
  . introduced inlined helper functions to simplify code
  . moved EXPORT_SYMBOL definitions next to function definition
- changes in sclp console driver
  . removed callback recursion to prevent stack overflow
- changes to CPI module
  . added check for sclp_add_request return code
  . changed printks to specify a message level
- changes to generic sclp tty layer
  . removed timed buffer retry after error (timers may not work in some
    situations)
  . introduced return code for sclp_emit_buffer
- changes to sclp tty driver
  . removed callback recursion
- changes to sclp vt220 driver
  . removed callback recursion
  . removed timed buffer retry after error
- modified sclp_init_mask to prevent problems with some compiler versions
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>