locking, m68k: Calculate thread_info offset with asm offset

m68k has the thread_info structure embedded in its task struct.
Therefore its not possible to implement current_thread_info()
by looking at the stack pointer and do some simple calculations
like most other architectures do it.

To return the thread_info pointer for a task two defines are
used. This works until the spinlock function bodies get moved
into an own header file and CONFIG_SPINLOCK_DEBUG is turned on.
That results into this compile error:

  In file included from include/linux/spinlock.h:378,
                   from include/linux/seqlock.h:29,
                   from include/linux/time.h:8,
                   from include/linux/timex.h:56,
                   from include/linux/sched.h:54,
                   from arch/m68k/kernel/asm-offsets.c:12:
  include/linux/spinlock_api_smp.h: In function '__spin_unlock_irq':
  include/linux/spinlock_api_smp.h:371: error: 'current' undeclared (first use in this function)
  include/linux/spinlock_api_smp.h:371: error: (Each undeclared identifier is reported only once
  include/linux/spinlock_api_smp.h:371: error: for each function it appears in.)

Including asm/current.h to asm-offsets.c wouldn't help since
the definition of struct task is needed. So we end up with ugly
header file include dependencies.

To solve this calculate the offset of the thread_info structure
into the task struct in asm-offsets.h and use the offset in
task_thread_info(). This works just like it does for IA64 as
well.

Signed-off-by: Heiko Carstens <[email protected]>
Acked-by: Peter Zijlstra <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Nick Piggin <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Horst Hartmann <[email protected]>
Cc: Christian Ehrhardt <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: David Miller <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Roman Zippel <[email protected]>
Cc: <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>

0 files changed, 0 insertions, 0 deletions