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[SPARC64]: Make debugging spinlocks usable again.
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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 <davem@davemloft.net>
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David S. Miller committed Aug 29, 2005
1 parent ca7c8d2 commit 442464a
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Showing 3 changed files with 38 additions and 65 deletions.
23 changes: 0 additions & 23 deletions arch/sparc64/kernel/sparc64_ksyms.c
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Original file line number Diff line number Diff line change
Expand Up @@ -99,17 +99,6 @@ extern int __ashrdi3(int, int);
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;

Expand Down Expand Up @@ -152,18 +141,6 @@ EXPORT_SYMBOL(_mcount);
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 */

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40 changes: 14 additions & 26 deletions arch/sparc64/lib/debuglocks.c
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Original file line number Diff line number Diff line change
Expand Up @@ -12,8 +12,6 @@

#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();
Expand Down Expand Up @@ -51,14 +49,13 @@ static inline void show_write (char *str, rwlock_t *lock, unsigned long caller)
#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)
Expand All @@ -84,12 +81,11 @@ void _do_spin_lock(spinlock_t *lock, char *str)
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))
Expand Down Expand Up @@ -118,14 +114,13 @@ void _do_spin_unlock(spinlock_t *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) {
Expand Down Expand Up @@ -157,15 +152,13 @@ void _do_read_lock (rwlock_t *rw, char *str)
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;
current->thread.smp_lock_count--;
Expand Down Expand Up @@ -193,14 +186,13 @@ void _do_read_unlock (rwlock_t *rw, char *str)
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) {
Expand Down Expand Up @@ -278,14 +270,12 @@ void _do_write_lock (rwlock_t *rw, char *str)
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;
rw->writer_cpu = NO_PROC_ID;
Expand Down Expand Up @@ -313,13 +303,11 @@ void _do_write_unlock(rwlock_t *rw)
}
}

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__(
" mov 1, %%g3\n"
Expand Down
40 changes: 24 additions & 16 deletions include/asm-sparc64/spinlock.h
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Original file line number Diff line number Diff line change
Expand Up @@ -132,12 +132,15 @@ do { \
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);

#define _raw_spin_trylock(lp) _do_spin_trylock(lp)
#define _raw_spin_lock(lock) _do_spin_lock(lock, "spin_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, (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)

Expand Down Expand Up @@ -279,45 +282,50 @@ typedef struct {
#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)

#define _raw_write_trylock(lock) \
({ 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; \
})
Expand Down

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