[PATCH] m68k: convert thread flags to use bit fields

Remove task_work structure, use the standard thread flags functions and use
shifts in entry.S to test the thread flags.  Add a few local labels to entry.S
to allow gas to generate short jumps.

Finally it changes a number of inline functions in thread_info.h to macros to
delay the current_thread_info() usage, which requires on m68k a structure
(task_struct) not yet defined at this point.

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Cc: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

3 files changed, 46 insertions, 52 deletions

diff --git a/arch/m68k/kernel/asm-offsets.c b/arch/m68k/kernel/asm-offsets.c
index 30beacfef8f..c787c5ba951 100644
--- a/arch/m68k/kernel/asm-offsets.c
+++ b/arch/m68k/kernel/asm-offsets.c
@@ -25,11 +25,6 @@ int main(void)
 	DEFINE(TASK_STATE, offsetof(struct task_struct, state));
 	DEFINE(TASK_FLAGS, offsetof(struct task_struct, flags));
 	DEFINE(TASK_PTRACE, offsetof(struct task_struct, ptrace));
-	DEFINE(TASK_WORK, offsetof(struct task_struct, thread.work));
-	DEFINE(TASK_NEEDRESCHED, offsetof(struct task_struct, thread.work.need_resched));
-	DEFINE(TASK_SYSCALL_TRACE, offsetof(struct task_struct, thread.work.syscall_trace));
-	DEFINE(TASK_SIGPENDING, offsetof(struct task_struct, thread.work.sigpending));
-	DEFINE(TASK_NOTIFY_RESUME, offsetof(struct task_struct, thread.work.notify_resume));
 	DEFINE(TASK_THREAD, offsetof(struct task_struct, thread));
 	DEFINE(TASK_INFO, offsetof(struct task_struct, thread.info));
 	DEFINE(TASK_MM, offsetof(struct task_struct, mm));
diff --git a/arch/m68k/kernel/entry.S b/arch/m68k/kernel/entry.S
index 23ca60a4555..320fde05dc6 100644
--- a/arch/m68k/kernel/entry.S
+++ b/arch/m68k/kernel/entry.S
@@ -44,9 +44,7 @@
 
 #include <asm/asm-offsets.h>
 
-.globl system_call, buserr, trap
-.globl resume, ret_from_exception
-.globl ret_from_signal
+.globl system_call, buserr, trap, resume
 .globl inthandler, sys_call_table
 .globl sys_fork, sys_clone, sys_vfork
 .globl ret_from_interrupt, bad_interrupt
@@ -58,7 +56,7 @@ ENTRY(buserr)
 	movel	%sp,%sp@-		| stack frame pointer argument
 	bsrl	buserr_c
 	addql	#4,%sp
-	jra	ret_from_exception
+	jra	.Lret_from_exception
 
 ENTRY(trap)
 	SAVE_ALL_INT
@@ -66,7 +64,7 @@ ENTRY(trap)
 	movel	%sp,%sp@-		| stack frame pointer argument
 	bsrl	trap_c
 	addql	#4,%sp
-	jra	ret_from_exception
+	jra	.Lret_from_exception
 
 	| After a fork we jump here directly from resume,
 	| so that %d1 contains the previous task
@@ -75,30 +73,31 @@ ENTRY(ret_from_fork)
 	movel	%d1,%sp@-
 	jsr	schedule_tail
 	addql	#4,%sp
-	jra	ret_from_exception
+	jra	.Lret_from_exception
 
-badsys:
-	movel	#-ENOSYS,%sp@(PT_D0)
-	jra	ret_from_exception
-
-do_trace:
+do_trace_entry:
 	movel	#-ENOSYS,%sp@(PT_D0)	| needed for strace
 	subql	#4,%sp
 	SAVE_SWITCH_STACK
 	jbsr	syscall_trace
 	RESTORE_SWITCH_STACK
 	addql	#4,%sp
-	movel	%sp@(PT_ORIG_D0),%d1
-	movel	#-ENOSYS,%d0
-	cmpl	#NR_syscalls,%d1
-	jcc	1f
-	jbsr	@(sys_call_table,%d1:l:4)@(0)
-1:	movel	%d0,%sp@(PT_D0)		| save the return value
-	subql	#4,%sp			| dummy return address
+	movel	%sp@(PT_ORIG_D0),%d0
+	cmpl	#NR_syscalls,%d0
+	jcs	syscall
+badsys:
+	movel	#-ENOSYS,%sp@(PT_D0)
+	jra	ret_from_syscall
+
+do_trace_exit:
+	subql	#4,%sp
 	SAVE_SWITCH_STACK
 	jbsr	syscall_trace
+	RESTORE_SWITCH_STACK
+	addql	#4,%sp
+	jra	.Lret_from_exception
 
-ret_from_signal:
+ENTRY(ret_from_signal)
 	RESTORE_SWITCH_STACK
 	addql	#4,%sp
 /* on 68040 complete pending writebacks if any */
@@ -111,7 +110,7 @@ ret_from_signal:
 	addql	#4,%sp
 1:
 #endif
-	jra	ret_from_exception
+	jra	.Lret_from_exception
 
 ENTRY(system_call)
 	SAVE_ALL_SYS
@@ -120,30 +119,34 @@ ENTRY(system_call)
 	| save top of frame
 	movel	%sp,%curptr@(TASK_THREAD+THREAD_ESP0)
 
-	tstb	%curptr@(TASK_SYSCALL_TRACE)
-	jne	do_trace
+	| syscall trace?
+	tstb	%curptr@(TASK_INFO+TINFO_FLAGS+2)
+	jmi	do_trace_entry
 	cmpl	#NR_syscalls,%d0
 	jcc	badsys
+syscall:
 	jbsr	@(sys_call_table,%d0:l:4)@(0)
 	movel	%d0,%sp@(PT_D0)		| save the return value
-
+ret_from_syscall:
 	|oriw	#0x0700,%sr
-	movel	%curptr@(TASK_WORK),%d0
+	movew	%curptr@(TASK_INFO+TINFO_FLAGS+2),%d0
 	jne	syscall_exit_work
 1:	RESTORE_ALL
 
 syscall_exit_work:
 	btst	#5,%sp@(PT_SR)		| check if returning to kernel
 	bnes	1b			| if so, skip resched, signals
-	tstw	%d0
-	jeq	do_signal_return
-	tstb	%d0
-	jne	do_delayed_trace
-
+	lslw	#1,%d0
+	jcs	do_trace_exit
+	jmi	do_delayed_trace
+	lslw	#8,%d0
+	jmi	do_signal_return
 	pea	resume_userspace
-	jmp	schedule
+	jra	schedule
+
 
-ret_from_exception:
+ENTRY(ret_from_exception)
+.Lret_from_exception:
 	btst	#5,%sp@(PT_SR)		| check if returning to kernel
 	bnes	1f			| if so, skip resched, signals
 	| only allow interrupts when we are really the last one on the
@@ -152,19 +155,18 @@ ret_from_exception:
 	andw	#ALLOWINT,%sr
 
 resume_userspace:
-	movel	%curptr@(TASK_WORK),%d0
-	lsrl	#8,%d0
+	moveb	%curptr@(TASK_INFO+TINFO_FLAGS+3),%d0
 	jne	exit_work
 1:	RESTORE_ALL
 
 exit_work:
 	| save top of frame
 	movel	%sp,%curptr@(TASK_THREAD+THREAD_ESP0)
-	tstb	%d0
-	jeq	do_signal_return
-
+	lslb	#1,%d0
+	jmi	do_signal_return
 	pea	resume_userspace
-	jmp	schedule
+	jra	schedule
+
 
 do_signal_return:
 	|andw	#ALLOWINT,%sr
@@ -254,7 +256,7 @@ ret_from_interrupt:
 
 	/* check if we need to do software interrupts */
 	tstl	irq_stat+CPUSTAT_SOFTIRQ_PENDING
-	jeq	ret_from_exception
+	jeq	.Lret_from_exception
 	pea	ret_from_exception
 	jra	do_softirq
 
diff --git a/arch/m68k/kernel/ptrace.c b/arch/m68k/kernel/ptrace.c
index 7e54422685c..540638ca81f 100644
--- a/arch/m68k/kernel/ptrace.c
+++ b/arch/m68k/kernel/ptrace.c
@@ -109,7 +109,7 @@ static inline void singlestep_disable(struct task_struct *child)
 {
 	unsigned long tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16);
 	put_reg(child, PT_SR, tmp);
-	child->thread.work.delayed_trace = 0;
+	clear_tsk_thread_flag(child, TIF_DELAYED_TRACE);
 }
 
 /*
@@ -118,7 +118,7 @@ static inline void singlestep_disable(struct task_struct *child)
 void ptrace_disable(struct task_struct *child)
 {
 	singlestep_disable(child);
-	child->thread.work.syscall_trace = 0;
+	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 }
 
 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
@@ -198,9 +198,9 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 			goto out_eio;
 
 		if (request == PTRACE_SYSCALL)
-			child->thread.work.syscall_trace = ~0;
+			set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 		else
-			child->thread.work.syscall_trace = 0;
+			clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 		child->exit_code = data;
 		singlestep_disable(child);
 		wake_up_process(child);
@@ -223,10 +223,10 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 		if (!valid_signal(data))
 			goto out_eio;
 
-		child->thread.work.syscall_trace = 0;
+		clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 		tmp = get_reg(child, PT_SR) | (TRACE_BITS << 16);
 		put_reg(child, PT_SR, tmp);
-		child->thread.work.delayed_trace = 1;
+		set_tsk_thread_flag(child, TIF_DELAYED_TRACE);
 
 		child->exit_code = data;
 		/* give it a chance to run. */
@@ -288,9 +288,6 @@ out_eio:
 
 asmlinkage void syscall_trace(void)
 {
-	if (!current->thread.work.delayed_trace &&
-	    !current->thread.work.syscall_trace)
-		return;
 	ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
 				 ? 0x80 : 0));
 	/*