Commit d25ba98a authored by Greg Ungerer's avatar Greg Ungerer
Browse files

m68k: remove thread_info struct from thread struct 



Currently on m68k we have a comeplete thread_info structure stored inside
of the thread_struct, and we also have it in the initial part of the kernel
stack. Mostly the code currently uses the one inside of the thread_struct,
only using the "task" pointer from the stack based one.

This is wasteful and confusing, we should only have the single instance of
thread_info inside the stack page. And this is the norm for all other
architectures.

This change makes m68k handle thread_info consistently on both MMU enabled
and non-MMU setups.

Signed-off-by: default avatarGreg Ungerer <gerg@uclinux.org>
parent 8d362b0d

arch/m68k/include/asm/processor.h

+0 −2
Original line number Diff line number Diff line
@@ -88,14 +88,12 @@ struct thread_struct { 
	unsigned long  fp[8*3];

	unsigned long  fpcntl[3];	/* fp control regs */

	unsigned char  fpstate[FPSTATESIZE];  /* floating point state */

	struct thread_info info;

};



#define INIT_THREAD  {							\

	.ksp	= sizeof(init_stack) + (unsigned long) init_stack,	\

	.sr	= PS_S,							\

	.fs	= __KERNEL_DS,						\

	.info	= INIT_THREAD_INFO(init_task),				\

}



#ifdef CONFIG_MMU

arch/m68k/include/asm/thread_info.h

+0 −30
Original line number Diff line number Diff line
@@ -47,34 +47,6 @@ struct thread_info { 


#define init_stack		(init_thread_union.stack)



#ifdef CONFIG_MMU



#ifndef __ASSEMBLY__

#include <asm/current.h>

#endif



#ifdef ASM_OFFSETS_C

#define task_thread_info(tsk)	((struct thread_info *) NULL)

#else

#include <asm/asm-offsets.h>

#define task_thread_info(tsk)	((struct thread_info *)((char *)tsk+TASK_INFO))

#endif



#define init_thread_info	(init_task.thread.info)

#define task_stack_page(tsk)	((tsk)->stack)

#define current_thread_info()	task_thread_info(current)



#define __HAVE_THREAD_FUNCTIONS



#define setup_thread_stack(p, org) ({			\

	*(struct task_struct **)(p)->stack = (p);	\

	task_thread_info(p)->task = (p);		\

})



#define end_of_stack(p)		((unsigned long *)(p)->stack + 1)



#else /* !CONFIG_MMU */



#ifndef __ASSEMBLY__

/* how to get the thread information struct from C */

static inline struct thread_info *current_thread_info(void)
@@ -92,8 +64,6 @@ static inline struct thread_info *current_thread_info(void) 


#define init_thread_info	(init_thread_union.thread_info)



#endif /* CONFIG_MMU */



/* entry.S relies on these definitions!

 * bits 0-7 are tested at every exception exit

 * bits 8-15 are also tested at syscall exit

arch/m68k/kernel/asm-offsets.c

+1 −1
Original line number Diff line number Diff line
@@ -24,7 +24,7 @@ int main(void) 
	/* offsets into the task struct */

	DEFINE(TASK_THREAD, offsetof(struct task_struct, thread));

	DEFINE(TASK_MM, offsetof(struct task_struct, mm));

	DEFINE(TASK_INFO, offsetof(struct task_struct, thread.info));

	DEFINE(TASK_STACK, offsetof(struct task_struct, stack));



	/* offsets into the thread struct */

	DEFINE(THREAD_KSP, offsetof(struct thread_struct, ksp));

arch/m68k/kernel/entry_mm.S

+21 −10
Original line number Diff line number Diff line
@@ -99,7 +99,8 @@ do_trace_exit: 
	jra	.Lret_from_exception



ENTRY(ret_from_signal)

	tstb	%curptr@(TASK_INFO+TINFO_FLAGS+2)

	movel	%curptr@(TASK_STACK),%a1

	tstb	%a1@(TINFO_FLAGS+2)

	jge	1f

	jbsr	syscall_trace

1:	RESTORE_SWITCH_STACK
@@ -120,11 +121,13 @@ ENTRY(system_call) 
	SAVE_ALL_SYS



	GET_CURRENT(%d1)

	movel	%d1,%a1



	| save top of frame

	movel	%sp,%curptr@(TASK_THREAD+THREAD_ESP0)



	| syscall trace?

	tstb	%curptr@(TASK_INFO+TINFO_FLAGS+2)

	tstb	%a1@(TINFO_FLAGS+2)

	jmi	do_trace_entry

	cmpl	#NR_syscalls,%d0

	jcc	badsys
@@ -133,7 +136,8 @@ syscall: 
	movel	%d0,%sp@(PT_OFF_D0)	| save the return value

ret_from_syscall:

	|oriw	#0x0700,%sr

	movew	%curptr@(TASK_INFO+TINFO_FLAGS+2),%d0

	movel	%curptr@(TASK_STACK),%a1

	movew	%a1@(TINFO_FLAGS+2),%d0

	jne	syscall_exit_work

1:	RESTORE_ALL
@@ -159,7 +163,8 @@ ENTRY(ret_from_exception) 
	andw	#ALLOWINT,%sr



resume_userspace:

	moveb	%curptr@(TASK_INFO+TINFO_FLAGS+3),%d0

	movel	%curptr@(TASK_STACK),%a1

	moveb	%a1@(TINFO_FLAGS+3),%d0

	jne	exit_work

1:	RESTORE_ALL
@@ -199,7 +204,8 @@ do_delayed_trace: 
ENTRY(auto_inthandler)

	SAVE_ALL_INT

	GET_CURRENT(%d0)

	addqb	#1,%curptr@(TASK_INFO+TINFO_PREEMPT+1)

	movel	%d0,%a1

	addqb	#1,%a1@(TINFO_PREEMPT+1)

					|  put exception # in d0

	bfextu	%sp@(PT_OFF_FORMATVEC){#4,#10},%d0

	subw	#VEC_SPUR,%d0
@@ -211,7 +217,8 @@ auto_irqhandler_fixup = . + 2 
	addql	#8,%sp			|  pop parameters off stack



ret_from_interrupt:

	subqb	#1,%curptr@(TASK_INFO+TINFO_PREEMPT+1)

	movel	%curptr@(TASK_STACK),%a1

	subqb	#1,%a1@(TINFO_PREEMPT+1)

	jeq	ret_from_last_interrupt

2:	RESTORE_ALL
@@ -232,7 +239,8 @@ ret_from_last_interrupt: 
ENTRY(user_inthandler)

	SAVE_ALL_INT

	GET_CURRENT(%d0)

	addqb	#1,%curptr@(TASK_INFO+TINFO_PREEMPT+1)

	movel	%d0,%a1

	addqb	#1,%a1@(TINFO_PREEMPT+1)

					|  put exception # in d0

	bfextu	%sp@(PT_OFF_FORMATVEC){#4,#10},%d0

user_irqvec_fixup = . + 2
@@ -243,7 +251,8 @@ user_irqvec_fixup = . + 2 
	jsr	do_IRQ			|  process the IRQ

	addql	#8,%sp			|  pop parameters off stack



	subqb	#1,%curptr@(TASK_INFO+TINFO_PREEMPT+1)

	movel	%curptr@(TASK_STACK),%a1

	subqb	#1,%a1@(TINFO_PREEMPT+1)

	jeq	ret_from_last_interrupt

	RESTORE_ALL
@@ -252,13 +261,15 @@ user_irqvec_fixup = . + 2 
ENTRY(bad_inthandler)

	SAVE_ALL_INT

	GET_CURRENT(%d0)

	addqb	#1,%curptr@(TASK_INFO+TINFO_PREEMPT+1)

	movel	%d0,%a1

	addqb	#1,%a1@(TINFO_PREEMPT+1)



	movel	%sp,%sp@-

	jsr	handle_badint

	addql	#4,%sp



	subqb	#1,%curptr@(TASK_INFO+TINFO_PREEMPT+1)

	movel	%curptr@(TASK_STACK),%a1

	subqb	#1,%a1@(TINFO_PREEMPT+1)

	jeq	ret_from_last_interrupt

	RESTORE_ALL

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