s390: add current_stack_pointer() helper function

Implement current_stack_pointer() helper function and use it
everywhere, instead of having several different inline assembly
variants.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h
index 1c4fe12..073e18b 100644 (file)
--- a/arch/s390/include/asm/processor.h
+++ b/arch/s390/include/asm/processor.h
@@ -203,6 +203,14 @@ unsigned long get_wchan(struct task_struct *p);
 /* Has task runtime instrumentation enabled ? */
 #define is_ri_task(tsk) (!!(tsk)->thread.ri_cb)
 
+static inline unsigned long current_stack_pointer(void)
+{
+       unsigned long sp;
+
+       asm volatile("la %0,0(15)" : "=a" (sp));
+       return sp;
+}
+
 static inline unsigned short stap(void)
 {
        unsigned short cpu_address;

diff --git a/arch/s390/kernel/dumpstack.c b/arch/s390/kernel/dumpstack.c
index 02bd02f..feda48f 100644 (file)
--- a/arch/s390/kernel/dumpstack.c
+++ b/arch/s390/kernel/dumpstack.c
@@ -67,12 +67,11 @@ static void show_trace(struct task_struct *task, unsigned long *stack)
 {
        const unsigned long frame_size =
                STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
-       register unsigned long __r15 asm ("15");
        unsigned long sp;
 
        sp = (unsigned long) stack;
        if (!sp)
-               sp = task ? task->thread.ksp : __r15;
+               sp = task ? task->thread.ksp : current_stack_pointer();
        printk("Call Trace:\n");
 #ifdef CONFIG_CHECK_STACK
        sp = __show_trace(sp,
@@ -95,15 +94,16 @@ static void show_trace(struct task_struct *task, unsigned long *stack)
 
 void show_stack(struct task_struct *task, unsigned long *sp)
 {
-       register unsigned long *__r15 asm ("15");
        unsigned long *stack;
        int i;
 
-       if (!sp)
-               stack = task ? (unsigned long *) task->thread.ksp : __r15;
-       else
-               stack = sp;
-
+       stack = sp;
+       if (!stack) {
+               if (!task)
+                       stack = (unsigned long *)current_stack_pointer();
+               else
+                       stack = (unsigned long *)task->thread.ksp;
+       }
        for (i = 0; i < 20; i++) {
                if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
                        break;

diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c
index f41d520..c373a1d 100644 (file)
--- a/arch/s390/kernel/irq.c
+++ b/arch/s390/kernel/irq.c
@@ -164,8 +164,7 @@ void do_softirq_own_stack(void)
 {
        unsigned long old, new;
 
-       /* Get current stack pointer. */
-       asm volatile("la %0,0(15)" : "=a" (old));
+       old = current_stack_pointer();
        /* Check against async. stack address range. */
        new = S390_lowcore.async_stack;
        if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) {

diff --git a/arch/s390/kernel/stacktrace.c b/arch/s390/kernel/stacktrace.c
index 3872d14..7dd8360 100644 (file)
--- a/arch/s390/kernel/stacktrace.c
+++ b/arch/s390/kernel/stacktrace.c
@@ -77,10 +77,9 @@ static void __save_stack_trace(struct stack_trace *trace, unsigned long sp)
 
 void save_stack_trace(struct stack_trace *trace)
 {
-       register unsigned long r15 asm ("15");
        unsigned long sp;
 
-       sp = r15;
+       sp = current_stack_pointer();
        __save_stack_trace(trace, sp);
        if (trace->nr_entries < trace->max_entries)
                trace->entries[trace->nr_entries++] = ULONG_MAX;
@@ -92,10 +91,8 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
        unsigned long sp, low, high;
 
        sp = tsk->thread.ksp;
-       if (tsk == current) {
-               /* Get current stack pointer. */
-               asm volatile("la %0,0(15)" : "=a" (sp));
-       }
+       if (tsk == current)
+               sp = current_stack_pointer();
        low = (unsigned long) task_stack_page(tsk);
        high = (unsigned long) task_pt_regs(tsk);
        save_context_stack(trace, sp, low, high, 1);