* m68k: remove thread_info struct from thread struct
@ 2011-09-05 4:41 gerg
2011-09-05 4:41 ` [PATCH] " gerg
0 siblings, 1 reply; 2+ messages in thread
From: gerg @ 2011-09-05 4:41 UTC (permalink / raw)
To: linux-m68k
The following patch cleans up the duplicated thread_info struct within
each task. m68knommu only used the stack based one, but m68k mostly
used the threaad_struct one. All other architectures only used the
stack based one.
Unfortunately it adds a couple of instructions into the exception
processing paths. This could be reduced a little, since the act of
calculating the current pointer (%a2) actually gets us the thread_info
pointer. I have not taken advantage of this just yet, though this patch
does take advantage of what the GET_CURRENT() macro does internally.
I have tested this on ARAnyM and it seems to work just fine. Of course
tested on ColdFire as well, no problems there.
Thoughts on this one?
Regards
Greg
^ permalink raw reply [flat|nested] 2+ messages in thread
* [PATCH] m68k: remove thread_info struct from thread struct
2011-09-05 4:41 m68k: remove thread_info struct from thread struct gerg
@ 2011-09-05 4:41 ` gerg
0 siblings, 0 replies; 2+ messages in thread
From: gerg @ 2011-09-05 4:41 UTC (permalink / raw)
To: linux-m68k; +Cc: Greg Ungerer
From: Greg Ungerer <gerg@uclinux.org>
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>
---
arch/m68k/include/asm/processor.h | 2 --
arch/m68k/include/asm/thread_info.h | 26 --------------------------
arch/m68k/kernel/asm-offsets.c | 2 +-
arch/m68k/kernel/entry_mm.S | 31 +++++++++++++++++++++----------
4 files changed, 22 insertions(+), 39 deletions(-)
diff --git a/arch/m68k/include/asm/processor.h b/arch/m68k/include/asm/processor.h
index 568facf..7ec0609 100644
--- a/arch/m68k/include/asm/processor.h
+++ b/arch/m68k/include/asm/processor.h
@@ -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
diff --git a/arch/m68k/include/asm/thread_info.h b/arch/m68k/include/asm/thread_info.h
index 6140b48..01cef3c 100644
--- a/arch/m68k/include/asm/thread_info.h
+++ b/arch/m68k/include/asm/thread_info.h
@@ -47,30 +47,6 @@ struct thread_info {
#define init_stack (init_thread_union.stack)
-#ifdef CONFIG_MMU
-
-#ifndef __ASSEMBLY__
-#include <asm/current.h>
-#endif
-
-#include <asm/asm-offsets.h>
-
-#define task_thread_info(tsk) ((struct thread_info *)((char *)tsk+TASK_INFO))
-#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)
@@ -88,8 +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
diff --git a/arch/m68k/kernel/asm-offsets.c b/arch/m68k/kernel/asm-offsets.c
index f6a54e2..a972b00 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 bd0ec05..ef81351 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
@@ -244,7 +252,8 @@ user_irqhandler_fixup = . + 2
jsr __m68k_handle_int | 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
@@ -253,13 +262,15 @@ user_irqhandler_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
--
1.7.0.4
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