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[PATCH] m68k: convert thread flags to use bit fields
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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 <[email protected]>
Cc: Al Viro <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Roman Zippel authored and Linus Torvalds committed Nov 14, 2005
1 parent abd0375 commit 3b66a1e
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Showing 8 changed files with 72 additions and 178 deletions.
6 changes: 2 additions & 4 deletions arch/m68k/fpsp040/skeleton.S
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Original file line number Diff line number Diff line change
Expand Up @@ -381,10 +381,8 @@ fpsp_done:
.Lnotkern:
SAVE_ALL_INT
GET_CURRENT(%d0)
tstb %curptr@(TASK_NEEDRESCHED)
jne ret_from_exception | deliver signals,
| reschedule etc..
RESTORE_ALL
| deliver signals, reschedule etc..
jra ret_from_exception

|
| mem_write --- write to user or supervisor address space
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6 changes: 2 additions & 4 deletions arch/m68k/ifpsp060/iskeleton.S
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Original file line number Diff line number Diff line change
Expand Up @@ -75,10 +75,8 @@ _060_isp_done:
.Lnotkern:
SAVE_ALL_INT
GET_CURRENT(%d0)
tstb %curptr@(TASK_NEEDRESCHED)
jne ret_from_exception | deliver signals,
| reschedule etc..
RESTORE_ALL
| deliver signals, reschedule etc..
jra ret_from_exception

|
| _060_real_chk():
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5 changes: 0 additions & 5 deletions arch/m68k/kernel/asm-offsets.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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));
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78 changes: 40 additions & 38 deletions arch/m68k/kernel/entry.S
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Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand All @@ -58,15 +56,15 @@ 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
GET_CURRENT(%d0)
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
Expand All @@ -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 */
Expand All @@ -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
Expand All @@ -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
Expand All @@ -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
Expand Down Expand Up @@ -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

Expand Down
15 changes: 6 additions & 9 deletions arch/m68k/kernel/ptrace.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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);
}

/*
Expand All @@ -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)
Expand Down Expand Up @@ -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);
Expand All @@ -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. */
Expand Down Expand Up @@ -288,9 +288,6 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)

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));
/*
Expand Down
12 changes: 0 additions & 12 deletions include/asm-m68k/processor.h
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Original file line number Diff line number Diff line change
Expand Up @@ -56,17 +56,6 @@ static inline void wrusp(unsigned long usp)
#endif
#define TASK_UNMAPPED_ALIGN(addr, off) PAGE_ALIGN(addr)

struct task_work {
unsigned char sigpending;
unsigned char notify_resume; /* request for notification on
userspace execution resumption */
char need_resched;
unsigned char delayed_trace; /* single step a syscall */
unsigned char syscall_trace; /* count of syscall interceptors */
unsigned char memdie; /* task was selected to be killed */
unsigned char pad[2];
};

struct thread_struct {
unsigned long ksp; /* kernel stack pointer */
unsigned long usp; /* user stack pointer */
Expand All @@ -79,7 +68,6 @@ struct thread_struct {
unsigned long fp[8*3];
unsigned long fpcntl[3]; /* fp control regs */
unsigned char fpstate[FPSTATESIZE]; /* floating point state */
struct task_work work;
struct thread_info info;
};

Expand Down
81 changes: 9 additions & 72 deletions include/asm-m68k/thread_info.h
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Original file line number Diff line number Diff line change
Expand Up @@ -6,12 +6,11 @@

struct thread_info {
struct task_struct *task; /* main task structure */
unsigned long flags;
struct exec_domain *exec_domain; /* execution domain */
int preempt_count; /* 0 => preemptable, <0 => BUG */
__u32 cpu; /* should always be 0 on m68k */
struct restart_block restart_block;

__u8 supervisor_stack[0];
};

#define PREEMPT_ACTIVE 0x4000000
Expand Down Expand Up @@ -49,76 +48,14 @@ struct thread_info {

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

#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
#define TIF_DELAYED_TRACE 1 /* single step a syscall */
#define TIF_NOTIFY_RESUME 2 /* resumption notification requested */
#define TIF_SIGPENDING 3 /* signal pending */
#define TIF_NEED_RESCHED 4 /* rescheduling necessary */
#define TIF_MEMDIE 5

extern int thread_flag_fixme(void);

/*
* flag set/clear/test wrappers
* - pass TIF_xxxx constants to these functions
/* entry.S relies on these definitions!
* bits 0-7 are tested at every exception exit
* bits 8-15 are also tested at syscall exit
*/

#define __set_tsk_thread_flag(tsk, flag, val) ({ \
switch (flag) { \
case TIF_SIGPENDING: \
tsk->thread.work.sigpending = val; \
break; \
case TIF_NEED_RESCHED: \
tsk->thread.work.need_resched = val; \
break; \
case TIF_SYSCALL_TRACE: \
tsk->thread.work.syscall_trace = val; \
break; \
case TIF_MEMDIE: \
tsk->thread.work.memdie = val; \
break; \
default: \
thread_flag_fixme(); \
} \
})

#define __get_tsk_thread_flag(tsk, flag) ({ \
int ___res; \
switch (flag) { \
case TIF_SIGPENDING: \
___res = tsk->thread.work.sigpending; \
break; \
case TIF_NEED_RESCHED: \
___res = tsk->thread.work.need_resched; \
break; \
case TIF_SYSCALL_TRACE: \
___res = tsk->thread.work.syscall_trace;\
break; \
case TIF_MEMDIE: \
___res = tsk->thread.work.memdie;\
break; \
default: \
___res = thread_flag_fixme(); \
} \
___res; \
})

#define __get_set_tsk_thread_flag(tsk, flag, val) ({ \
int __res = __get_tsk_thread_flag(tsk, flag); \
__set_tsk_thread_flag(tsk, flag, val); \
__res; \
})

#define set_tsk_thread_flag(tsk, flag) __set_tsk_thread_flag(tsk, flag, ~0)
#define clear_tsk_thread_flag(tsk, flag) __set_tsk_thread_flag(tsk, flag, 0)
#define test_and_set_tsk_thread_flag(tsk, flag) __get_set_tsk_thread_flag(tsk, flag, ~0)
#define test_tsk_thread_flag(tsk, flag) __get_tsk_thread_flag(tsk, flag)

#define set_thread_flag(flag) set_tsk_thread_flag(current, flag)
#define clear_thread_flag(flag) clear_tsk_thread_flag(current, flag)
#define test_thread_flag(flag) test_tsk_thread_flag(current, flag)

#define set_need_resched() set_thread_flag(TIF_NEED_RESCHED)
#define clear_need_resched() clear_thread_flag(TIF_NEED_RESCHED)
#define TIF_SIGPENDING 6 /* signal pending */
#define TIF_NEED_RESCHED 7 /* rescheduling necessary */
#define TIF_DELAYED_TRACE 14 /* single step a syscall */
#define TIF_SYSCALL_TRACE 15 /* syscall trace active */
#define TIF_MEMDIE 16

#endif /* _ASM_M68K_THREAD_INFO_H */
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