Commit-ID: 0ee000e5e8fa2e5c760250be0d78d5906e3eb94b Gitweb: http://git.kernel.org/tip/0ee000e5e8fa2e5c760250be0d78d5906e3eb94b Author: Heiko Carstens <heiko.carstens@xxxxxxxxxx> AuthorDate: Mon, 31 Aug 2009 14:43:35 +0200 Committer: Ingo Molnar <mingo@xxxxxxx> CommitDate: Mon, 31 Aug 2009 18:08:49 +0200 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 <heiko.carstens@xxxxxxxxxx> Acked-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> Cc: Nick Piggin <nickpiggin@xxxxxxxxxxxx> Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx> Cc: Horst Hartmann <horsth@xxxxxxxxxxxxxxxxxx> Cc: Christian Ehrhardt <ehrhardt@xxxxxxxxxxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: David Miller <davem@xxxxxxxxxxxxx> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Cc: Paul Mackerras <paulus@xxxxxxxxx> Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> Cc: Roman Zippel <zippel@xxxxxxxxxxxxxx> Cc: <linux-arch@xxxxxxxxxxxxxxx> LKML-Reference: <20090831124417.329662275@xxxxxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxx> --- arch/m68k/include/asm/thread_info_mm.h | 11 ++++++++++- arch/m68k/kernel/asm-offsets.c | 5 +++++ 2 files changed, 15 insertions(+), 1 deletions(-) diff --git a/arch/m68k/include/asm/thread_info_mm.h b/arch/m68k/include/asm/thread_info_mm.h index 6ea5c33..b6da388 100644 --- a/arch/m68k/include/asm/thread_info_mm.h +++ b/arch/m68k/include/asm/thread_info_mm.h @@ -1,6 +1,10 @@ #ifndef _ASM_M68K_THREAD_INFO_H #define _ASM_M68K_THREAD_INFO_H +#ifndef ASM_OFFSETS_C +#include <asm/asm-offsets.h> +#endif +#include <asm/current.h> #include <asm/types.h> #include <asm/page.h> @@ -31,7 +35,12 @@ struct thread_info { #define init_thread_info (init_task.thread.info) #define init_stack (init_thread_union.stack) -#define task_thread_info(tsk) (&(tsk)->thread.info) +#ifdef ASM_OFFSETS_C +#define task_thread_info(tsk) ((struct thread_info *) NULL) +#else +#define task_thread_info(tsk) ((struct thread_info *)((char *)tsk+TASK_TINFO)) +#endif + #define task_stack_page(tsk) ((tsk)->stack) #define current_thread_info() task_thread_info(current) diff --git a/arch/m68k/kernel/asm-offsets.c b/arch/m68k/kernel/asm-offsets.c index 0cffab8..25d6b72 100644 --- a/arch/m68k/kernel/asm-offsets.c +++ b/arch/m68k/kernel/asm-offsets.c @@ -8,6 +8,8 @@ * #defines from the assembly-language output. */ +#define ASM_OFFSETS_C + #include <linux/stddef.h> #include <linux/sched.h> #include <linux/kernel_stat.h> @@ -27,6 +29,9 @@ int main(void) DEFINE(TASK_INFO, offsetof(struct task_struct, thread.info)); DEFINE(TASK_MM, offsetof(struct task_struct, mm)); DEFINE(TASK_ACTIVE_MM, offsetof(struct task_struct, active_mm)); +#ifdef CONFIG_MMU + DEFINE(TASK_TINFO, offsetof(struct task_struct, thread.info)); +#endif /* offsets into the thread struct */ DEFINE(THREAD_KSP, offsetof(struct thread_struct, ksp)); -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
