[SPARC64]: Make debugging spinlocks usable again.

When the spinlock routines were moved out of line into
kernel/spinlock.c this made it so that the debugging
spinlocks record lock acquisition program counts in the
kernel/spinlock.c functions not in their callers.
This makes the debugging info kind of useless.

So record the correct caller's program counter and
now this feature is useful once more.

Signed-off-by: David S. Miller <[e-mail]>

arch/sparc64/kernel/sparc64_ksyms.c

···
 extern void dump_thread(struct pt_regs *, struct user *);
 extern int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs);
 
-#if defined(CONFIG_SMP) && defined(CONFIG_DEBUG_SPINLOCK)
-extern void _do_spin_lock (spinlock_t *lock, char *str);
-extern void _do_spin_unlock (spinlock_t *lock);
-extern int _spin_trylock (spinlock_t *lock);
-extern void _do_read_lock(rwlock_t *rw, char *str);
-extern void _do_read_unlock(rwlock_t *rw, char *str);
-extern void _do_write_lock(rwlock_t *rw, char *str);
-extern void _do_write_unlock(rwlock_t *rw);
-extern int _do_write_trylock(rwlock_t *rw, char *str);
-#endif
-
 extern unsigned long phys_base;
 extern unsigned long pfn_base;
 
···
 /* CPU online map and active count.  */
 EXPORT_SYMBOL(cpu_online_map);
 EXPORT_SYMBOL(phys_cpu_present_map);
-
-/* Spinlock debugging library, optional. */
-#ifdef CONFIG_DEBUG_SPINLOCK
-EXPORT_SYMBOL(_do_spin_lock);
-EXPORT_SYMBOL(_do_spin_unlock);
-EXPORT_SYMBOL(_spin_trylock);
-EXPORT_SYMBOL(_do_read_lock);
-EXPORT_SYMBOL(_do_read_unlock);
-EXPORT_SYMBOL(_do_write_lock);
-EXPORT_SYMBOL(_do_write_unlock);
-EXPORT_SYMBOL(_do_write_trylock);
-#endif
 
 EXPORT_SYMBOL(smp_call_function);
 #endif /* CONFIG_SMP */

arch/sparc64/lib/debuglocks.c

···
 
 #ifdef CONFIG_SMP
 
-#define GET_CALLER(PC) __asm__ __volatile__("mov %%i7, %0" : "=r" (PC))
-
 static inline void show (char *str, spinlock_t *lock, unsigned long caller)
 {
 	int cpu = smp_processor_id();
···
 #undef INIT_STUCK
 #define INIT_STUCK 100000000
 
-void _do_spin_lock(spinlock_t *lock, char *str)
+void _do_spin_lock(spinlock_t *lock, char *str, unsigned long caller)
 {
-	unsigned long caller, val;
+	unsigned long val;
 	int stuck = INIT_STUCK;
 	int cpu = get_cpu();
 	int shown = 0;
 
-	GET_CALLER(caller);
 again:
 	__asm__ __volatile__("ldstub [%1], %0"
 			     : "=r" (val)
···
 	put_cpu();
 }
 
-int _do_spin_trylock(spinlock_t *lock)
+int _do_spin_trylock(spinlock_t *lock, unsigned long caller)
 {
-	unsigned long val, caller;
+	unsigned long val;
 	int cpu = get_cpu();
 
-	GET_CALLER(caller);
 	__asm__ __volatile__("ldstub [%1], %0"
 			     : "=r" (val)
 			     : "r" (&(lock->lock))
···
 
 /* Keep INIT_STUCK the same... */
 
-void _do_read_lock (rwlock_t *rw, char *str)
+void _do_read_lock(rwlock_t *rw, char *str, unsigned long caller)
 {
-	unsigned long caller, val;
+	unsigned long val;
 	int stuck = INIT_STUCK;
 	int cpu = get_cpu();
 	int shown = 0;
 
-	GET_CALLER(caller);
 wlock_again:
 	/* Wait for any writer to go away.  */
 	while (((long)(rw->lock)) < 0) {
···
 	put_cpu();
 }
 
-void _do_read_unlock (rwlock_t *rw, char *str)
+void _do_read_unlock(rwlock_t *rw, char *str, unsigned long caller)
 {
-	unsigned long caller, val;
+	unsigned long val;
 	int stuck = INIT_STUCK;
 	int cpu = get_cpu();
 	int shown = 0;
-
-	GET_CALLER(caller);
 
 	/* Drop our identity _first_. */
 	rw->reader_pc[cpu] = 0;
···
 	put_cpu();
 }
 
-void _do_write_lock (rwlock_t *rw, char *str)
+void _do_write_lock(rwlock_t *rw, char *str, unsigned long caller)
 {
-	unsigned long caller, val;
+	unsigned long val;
 	int stuck = INIT_STUCK;
 	int cpu = get_cpu();
 	int shown = 0;
 
-	GET_CALLER(caller);
 wlock_again:
 	/* Spin while there is another writer. */
 	while (((long)rw->lock) < 0) {
···
 	put_cpu();
 }
 
-void _do_write_unlock(rwlock_t *rw)
+void _do_write_unlock(rwlock_t *rw, unsigned long caller)
 {
-	unsigned long caller, val;
+	unsigned long val;
 	int stuck = INIT_STUCK;
 	int shown = 0;
-
-	GET_CALLER(caller);
 
 	/* Drop our identity _first_ */
 	rw->writer_pc = 0;
···
 	}
 }
 
-int _do_write_trylock (rwlock_t *rw, char *str)
+int _do_write_trylock(rwlock_t *rw, char *str, unsigned long caller)
 {
-	unsigned long caller, val;
+	unsigned long val;
 	int cpu = get_cpu();
-
-	GET_CALLER(caller);
 
 	/* Try to acuire the write bit.  */
 	__asm__ __volatile__(

include/asm-sparc64/spinlock.h

···
 	membar("#LoadLoad"); \
 } while((__lock)->lock)
 
-extern void _do_spin_lock (spinlock_t *lock, char *str);
-extern void _do_spin_unlock (spinlock_t *lock);
-extern int _do_spin_trylock (spinlock_t *lock);
+extern void _do_spin_lock(spinlock_t *lock, char *str, unsigned long caller);
+extern void _do_spin_unlock(spinlock_t *lock);
+extern int _do_spin_trylock(spinlock_t *lock, unsigned long caller);
 
-#define _raw_spin_trylock(lp)	_do_spin_trylock(lp)
-#define _raw_spin_lock(lock)	_do_spin_lock(lock, "spin_lock")
+#define _raw_spin_trylock(lp)	\
+	_do_spin_trylock(lp, (unsigned long) __builtin_return_address(0))
+#define _raw_spin_lock(lock)	\
+	_do_spin_lock(lock, "spin_lock", \
+		      (unsigned long) __builtin_return_address(0))
 #define _raw_spin_unlock(lock)	_do_spin_unlock(lock)
 #define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
 
···
 #define RW_LOCK_UNLOCKED	(rwlock_t) { 0, 0, 0xff, { } }
 #define rwlock_init(lp) do { *(lp) = RW_LOCK_UNLOCKED; } while(0)
 
-extern void _do_read_lock(rwlock_t *rw, char *str);
-extern void _do_read_unlock(rwlock_t *rw, char *str);
-extern void _do_write_lock(rwlock_t *rw, char *str);
-extern void _do_write_unlock(rwlock_t *rw);
-extern int _do_write_trylock(rwlock_t *rw, char *str);
+extern void _do_read_lock(rwlock_t *rw, char *str, unsigned long caller);
+extern void _do_read_unlock(rwlock_t *rw, char *str, unsigned long caller);
+extern void _do_write_lock(rwlock_t *rw, char *str, unsigned long caller);
+extern void _do_write_unlock(rwlock_t *rw, unsigned long caller);
+extern int _do_write_trylock(rwlock_t *rw, char *str, unsigned long caller);
 
 #define _raw_read_lock(lock) \
 do {	unsigned long flags; \
 	local_irq_save(flags); \
-	_do_read_lock(lock, "read_lock"); \
+	_do_read_lock(lock, "read_lock", \
+		      (unsigned long) __builtin_return_address(0)); \
 	local_irq_restore(flags); \
 } while(0)
 
 #define _raw_read_unlock(lock) \
 do {	unsigned long flags; \
 	local_irq_save(flags); \
-	_do_read_unlock(lock, "read_unlock"); \
+	_do_read_unlock(lock, "read_unlock", \
+		      (unsigned long) __builtin_return_address(0)); \
 	local_irq_restore(flags); \
 } while(0)
 
 #define _raw_write_lock(lock) \
 do {	unsigned long flags; \
 	local_irq_save(flags); \
-	_do_write_lock(lock, "write_lock"); \
+	_do_write_lock(lock, "write_lock", \
+		      (unsigned long) __builtin_return_address(0)); \
 	local_irq_restore(flags); \
 } while(0)
 
 #define _raw_write_unlock(lock) \
 do {	unsigned long flags; \
 	local_irq_save(flags); \
-	_do_write_unlock(lock); \
+	_do_write_unlock(lock, \
+		      (unsigned long) __builtin_return_address(0)); \
 	local_irq_restore(flags); \
 } while(0)
 
···
 ({	unsigned long flags; \
 	int val; \
 	local_irq_save(flags); \
-	val = _do_write_trylock(lock, "write_trylock"); \
+	val = _do_write_trylock(lock, "write_trylock", \
+				(unsigned long) __builtin_return_address(0)); \
 	local_irq_restore(flags); \
 	val; \
 })