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: Greg Ungerer <gerg@uclinux.org>

2 files changed, 22 insertions, 11 deletions

diff --git a/arch/m68k/kernel/asm-offsets.c b/arch/m68k/kernel/asm-offsets.c
index f6a54e203e8..a972b00cd77 100644
--- a/arch/m68k/kernel/asm-offsets.c
+++ b/arch/m68k/kernel/asm-offsets.c
@@ -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));
diff --git a/arch/m68k/kernel/entry_mm.S b/arch/m68k/kernel/entry_mm.S
index c713f514843..675a854966a 100644
--- a/arch/m68k/kernel/entry_mm.S
+++ b/arch/m68k/kernel/entry_mm.S
@@ -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