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 <heiko.carstens@de.ibm.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Horst Hartmann <horsth@linux.vnet.ibm.com>
Cc: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: David Miller <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: <linux-arch@vger.kernel.org>
LKML-Reference: <20090831124417.329662275@de.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
67 lines
1.9 KiB
C
67 lines
1.9 KiB
C
#ifndef _ASM_M68K_THREAD_INFO_H
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#define _ASM_M68K_THREAD_INFO_H
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#ifndef ASM_OFFSETS_C
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#include <asm/asm-offsets.h>
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#endif
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#include <asm/current.h>
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#include <asm/types.h>
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#include <asm/page.h>
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struct thread_info {
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struct task_struct *task; /* main task structure */
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unsigned long flags;
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struct exec_domain *exec_domain; /* execution domain */
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int preempt_count; /* 0 => preemptable, <0 => BUG */
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__u32 cpu; /* should always be 0 on m68k */
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struct restart_block restart_block;
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};
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#define PREEMPT_ACTIVE 0x4000000
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#define INIT_THREAD_INFO(tsk) \
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{ \
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.task = &tsk, \
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.exec_domain = &default_exec_domain, \
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.preempt_count = INIT_PREEMPT_COUNT, \
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.restart_block = { \
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.fn = do_no_restart_syscall, \
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}, \
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}
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/* THREAD_SIZE should be 8k, so handle differently for 4k and 8k machines */
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#define THREAD_SIZE_ORDER (13 - PAGE_SHIFT)
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#define init_thread_info (init_task.thread.info)
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#define init_stack (init_thread_union.stack)
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#ifdef ASM_OFFSETS_C
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#define task_thread_info(tsk) ((struct thread_info *) NULL)
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#else
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#define task_thread_info(tsk) ((struct thread_info *)((char *)tsk+TASK_TINFO))
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#endif
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#define task_stack_page(tsk) ((tsk)->stack)
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#define current_thread_info() task_thread_info(current)
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#define __HAVE_THREAD_FUNCTIONS
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#define setup_thread_stack(p, org) ({ \
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*(struct task_struct **)(p)->stack = (p); \
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task_thread_info(p)->task = (p); \
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})
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#define end_of_stack(p) ((unsigned long *)(p)->stack + 1)
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/* entry.S relies on these definitions!
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* bits 0-7 are tested at every exception exit
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* bits 8-15 are also tested at syscall exit
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*/
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#define TIF_SIGPENDING 6 /* signal pending */
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#define TIF_NEED_RESCHED 7 /* rescheduling necessary */
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#define TIF_DELAYED_TRACE 14 /* single step a syscall */
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#define TIF_SYSCALL_TRACE 15 /* syscall trace active */
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#define TIF_MEMDIE 16
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#define TIF_FREEZE 17 /* thread is freezing for suspend */
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#endif /* _ASM_M68K_THREAD_INFO_H */
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