arch/sparc64/lib/debuglocks.c - kernel/msm-4.19 - Gitiles

 /* $Id: debuglocks.c,v 1.9 2001/11/17 00:10:48 davem Exp $
  * debuglocks.c: Debugging versions of SMP locking primitives.
  *
  * Copyright (C) 1998 David S. Miller (davem@redhat.com)
  */

 #include <linux/config.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
 #include <linux/spinlock.h>
 #include <asm/system.h>

 #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();

 	printk("%s(%p) CPU#%d stuck at %08x, owner PC(%08x):CPU(%x)\n",
 	       str, lock, cpu, (unsigned int) caller,
 	       lock->owner_pc, lock->owner_cpu);
 }

 static inline void show_read (char *str, rwlock_t *lock, unsigned long caller)
 {
 	int cpu = smp_processor_id();

 	printk("%s(%p) CPU#%d stuck at %08x, writer PC(%08x):CPU(%x)\n",
 	       str, lock, cpu, (unsigned int) caller,
 	       lock->writer_pc, lock->writer_cpu);
 }

 static inline void show_write (char *str, rwlock_t *lock, unsigned long caller)
 {
 	int cpu = smp_processor_id();
 	int i;

 	printk("%s(%p) CPU#%d stuck at %08x\n",
 	       str, lock, cpu, (unsigned int) caller);
 	printk("Writer: PC(%08x):CPU(%x)\n",
 	       lock->writer_pc, lock->writer_cpu);
 	printk("Readers:");
 	for (i = 0; i < NR_CPUS; i++)
 		if (lock->reader_pc[i])
 			printk(" %d[%08x]", i, lock->reader_pc[i]);
 	printk("\n");
 }

 #undef INIT_STUCK
 #define INIT_STUCK 100000000

 void _do_spin_lock(spinlock_t *lock, char *str)
 {
 	unsigned long caller, val;
 	int stuck = INIT_STUCK;
 	int cpu = get_cpu();
 	int shown = 0;

 	GET_CALLER(caller);
 again:
 	__asm__ __volatile__("ldstub [%1], %0"
 			     : "=r" (val)
 			     : "r" (&(lock->lock))
 			     : "memory");
 	membar("#StoreLoad | #StoreStore");
 	if (val) {
 		while (lock->lock) {
 			if (!--stuck) {
 				if (shown++ <= 2)
 					show(str, lock, caller);
 				stuck = INIT_STUCK;
 			}
 			membar("#LoadLoad");
 		}
 		goto again;
 	}
 	lock->owner_pc = ((unsigned int)caller);
 	lock->owner_cpu = cpu;
 	current->thread.smp_lock_count++;
 	current->thread.smp_lock_pc = ((unsigned int)caller);

 	put_cpu();
 }

 int _do_spin_trylock(spinlock_t *lock)
 {
 	unsigned long val, caller;
 	int cpu = get_cpu();

 	GET_CALLER(caller);
 	__asm__ __volatile__("ldstub [%1], %0"
 			     : "=r" (val)
 			     : "r" (&(lock->lock))
 			     : "memory");
 	membar("#StoreLoad | #StoreStore");
 	if (!val) {
 		lock->owner_pc = ((unsigned int)caller);
 		lock->owner_cpu = cpu;
 		current->thread.smp_lock_count++;
 		current->thread.smp_lock_pc = ((unsigned int)caller);
 	}

 	put_cpu();

 	return val == 0;
 }

 void _do_spin_unlock(spinlock_t *lock)
 {
 	lock->owner_pc = 0;
 	lock->owner_cpu = NO_PROC_ID;
 	membar("#StoreStore | #LoadStore");
 	lock->lock = 0;
 	current->thread.smp_lock_count--;
 }

 /* Keep INIT_STUCK the same... */

 void _do_read_lock (rwlock_t *rw, char *str)
 {
 	unsigned long caller, 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) {
 		if (!--stuck) {
 			if (shown++ <= 2)
 				show_read(str, rw, caller);
 			stuck = INIT_STUCK;
 		}
 		membar("#LoadLoad");
 	}
 	/* Try once to increment the counter.  */
 	__asm__ __volatile__(
 "	ldx		[%0], %%g1\n"
 "	brlz,a,pn	%%g1, 2f\n"
 "	 mov		1, %0\n"
 "	add		%%g1, 1, %%g7\n"
 "	casx		[%0], %%g1, %%g7\n"
 "	sub		%%g1, %%g7, %0\n"
 "2:"	: "=r" (val)
 	: "0" (&(rw->lock))
 	: "g1", "g7", "memory");
 	membar("#StoreLoad | #StoreStore");
 	if (val)
 		goto wlock_again;
 	rw->reader_pc[cpu] = ((unsigned int)caller);
 	current->thread.smp_lock_count++;
 	current->thread.smp_lock_pc = ((unsigned int)caller);

 	put_cpu();
 }

 void _do_read_unlock (rwlock_t *rw, char *str)
 {
 	unsigned long caller, 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--;
 runlock_again:
 	/* Spin trying to decrement the counter using casx.  */
 	__asm__ __volatile__(
 "	membar	#StoreLoad | #LoadLoad\n"
 "	ldx	[%0], %%g1\n"
 "	sub	%%g1, 1, %%g7\n"
 "	casx	[%0], %%g1, %%g7\n"
 "	membar	#StoreLoad | #StoreStore\n"
 "	sub	%%g1, %%g7, %0\n"
 	: "=r" (val)
 	: "0" (&(rw->lock))
 	: "g1", "g7", "memory");
 	if (val) {
 		if (!--stuck) {
 			if (shown++ <= 2)
 				show_read(str, rw, caller);
 			stuck = INIT_STUCK;
 		}
 		goto runlock_again;
 	}

 	put_cpu();
 }

 void _do_write_lock (rwlock_t *rw, char *str)
 {
 	unsigned long caller, 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) {
 		if (!--stuck) {
 			if (shown++ <= 2)
 				show_write(str, rw, caller);
 			stuck = INIT_STUCK;
 		}
 		membar("#LoadLoad");
 	}

 	/* Try to acuire the write bit.  */
 	__asm__ __volatile__(
 "	mov	1, %%g3\n"
 "	sllx	%%g3, 63, %%g3\n"
 "	ldx	[%0], %%g1\n"
 "	brlz,pn	%%g1, 1f\n"
 "	 or	%%g1, %%g3, %%g7\n"
 "	casx	[%0], %%g1, %%g7\n"
 "	membar	#StoreLoad | #StoreStore\n"
 "	ba,pt	%%xcc, 2f\n"
 "	 sub	%%g1, %%g7, %0\n"
 "1:	mov	1, %0\n"
 "2:"	: "=r" (val)
 	: "0" (&(rw->lock))
 	: "g3", "g1", "g7", "memory");
 	if (val) {
 		/* We couldn't get the write bit. */
 		if (!--stuck) {
 			if (shown++ <= 2)
 				show_write(str, rw, caller);
 			stuck = INIT_STUCK;
 		}
 		goto wlock_again;
 	}
 	if ((rw->lock & ((1UL<<63)-1UL)) != 0UL) {
 		/* Readers still around, drop the write
 		 * lock, spin, and try again.
 		 */
 		if (!--stuck) {
 			if (shown++ <= 2)
 				show_write(str, rw, caller);
 			stuck = INIT_STUCK;
 		}
 		__asm__ __volatile__(
 "		mov	1, %%g3\n"
 "		sllx	%%g3, 63, %%g3\n"
 "1:		ldx	[%0], %%g1\n"
 "		andn	%%g1, %%g3, %%g7\n"
 "		casx	[%0], %%g1, %%g7\n"
 "		cmp	%%g1, %%g7\n"
 "		membar	#StoreLoad | #StoreStore\n"
 "		bne,pn	%%xcc, 1b\n"
 "		 nop"
 		: /* no outputs */
 		: "r" (&(rw->lock))
 		: "g3", "g1", "g7", "cc", "memory");
 		while(rw->lock != 0) {
 			if (!--stuck) {
 				if (shown++ <= 2)
 					show_write(str, rw, caller);
 				stuck = INIT_STUCK;
 			}
 			membar("#LoadLoad");
 		}
 		goto wlock_again;
 	}

 	/* We have it, say who we are. */
 	rw->writer_pc = ((unsigned int)caller);
 	rw->writer_cpu = cpu;
 	current->thread.smp_lock_count++;
 	current->thread.smp_lock_pc = ((unsigned int)caller);

 	put_cpu();
 }

 void _do_write_unlock(rwlock_t *rw)
 {
 	unsigned long caller, 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;
 	current->thread.smp_lock_count--;
 wlock_again:
 	__asm__ __volatile__(
 "	membar	#StoreLoad | #LoadLoad\n"
 "	mov	1, %%g3\n"
 "	sllx	%%g3, 63, %%g3\n"
 "	ldx	[%0], %%g1\n"
 "	andn	%%g1, %%g3, %%g7\n"
 "	casx	[%0], %%g1, %%g7\n"
 "	membar	#StoreLoad | #StoreStore\n"
 "	sub	%%g1, %%g7, %0\n"
 	: "=r" (val)
 	: "0" (&(rw->lock))
 	: "g3", "g1", "g7", "memory");
 	if (val) {
 		if (!--stuck) {
 			if (shown++ <= 2)
 				show_write("write_unlock", rw, caller);
 			stuck = INIT_STUCK;
 		}
 		goto wlock_again;
 	}
 }

 int _do_write_trylock (rwlock_t *rw, char *str)
 {
 	unsigned long caller, val;
 	int cpu = get_cpu();

 	GET_CALLER(caller);

 	/* Try to acuire the write bit.  */
 	__asm__ __volatile__(
 "	mov	1, %%g3\n"
 "	sllx	%%g3, 63, %%g3\n"
 "	ldx	[%0], %%g1\n"
 "	brlz,pn	%%g1, 1f\n"
 "	 or	%%g1, %%g3, %%g7\n"
 "	casx	[%0], %%g1, %%g7\n"
 "	membar	#StoreLoad | #StoreStore\n"
 "	ba,pt	%%xcc, 2f\n"
 "	 sub	%%g1, %%g7, %0\n"
 "1:	mov	1, %0\n"
 "2:"	: "=r" (val)
 	: "0" (&(rw->lock))
 	: "g3", "g1", "g7", "memory");

 	if (val) {
 		put_cpu();
 		return 0;
 	}

 	if ((rw->lock & ((1UL<<63)-1UL)) != 0UL) {
 		/* Readers still around, drop the write
 		 * lock, return failure.
 		 */
 		__asm__ __volatile__(
 "		mov	1, %%g3\n"
 "		sllx	%%g3, 63, %%g3\n"
 "1:		ldx	[%0], %%g1\n"
 "		andn	%%g1, %%g3, %%g7\n"
 "		casx	[%0], %%g1, %%g7\n"
 "		cmp	%%g1, %%g7\n"
 "		membar	#StoreLoad | #StoreStore\n"
 "		bne,pn	%%xcc, 1b\n"
 "		 nop"
 		: /* no outputs */
 		: "r" (&(rw->lock))
 		: "g3", "g1", "g7", "cc", "memory");

 		put_cpu();

 		return 0;
 	}

 	/* We have it, say who we are. */
 	rw->writer_pc = ((unsigned int)caller);
 	rw->writer_cpu = cpu;
 	current->thread.smp_lock_count++;
 	current->thread.smp_lock_pc = ((unsigned int)caller);

 	put_cpu();

 	return 1;
 }

 #endif /* CONFIG_SMP */
	/* $Id: debuglocks.c,v 1.9 2001/11/17 00:10:48 davem Exp $
	* debuglocks.c: Debugging versions of SMP locking primitives.
	*
	* Copyright (C) 1998 David S. Miller (davem@redhat.com)
	*/

	#include <linux/config.h>
	#include <linux/kernel.h>
	#include <linux/sched.h>
	#include <linux/spinlock.h>
	#include <asm/system.h>

	#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();

	printk("%s(%p) CPU#%d stuck at %08x, owner PC(%08x):CPU(%x)\n",
	str, lock, cpu, (unsigned int) caller,
	lock->owner_pc, lock->owner_cpu);
	}

	static inline void show_read (char str, rwlock_t lock, unsigned long caller)
	{
	int cpu = smp_processor_id();

	printk("%s(%p) CPU#%d stuck at %08x, writer PC(%08x):CPU(%x)\n",
	str, lock, cpu, (unsigned int) caller,
	lock->writer_pc, lock->writer_cpu);
	}

	static inline void show_write (char str, rwlock_t lock, unsigned long caller)
	{
	int cpu = smp_processor_id();
	int i;

	printk("%s(%p) CPU#%d stuck at %08x\n",
	str, lock, cpu, (unsigned int) caller);
	printk("Writer: PC(%08x):CPU(%x)\n",
	lock->writer_pc, lock->writer_cpu);
	printk("Readers:");
	for (i = 0; i < NR_CPUS; i++)
	if (lock->reader_pc[i])
	printk(" %d[%08x]", i, lock->reader_pc[i]);
	printk("\n");
	}

	#undef INIT_STUCK
	#define INIT_STUCK 100000000

	void _do_spin_lock(spinlock_t lock, char str)
	{
	unsigned long caller, val;
	int stuck = INIT_STUCK;
	int cpu = get_cpu();
	int shown = 0;

	GET_CALLER(caller);
	again:
	__asm__ __volatile__("ldstub [%1], %0"
	: "=r" (val)
	: "r" (&(lock->lock))
	: "memory");
	membar("#StoreLoad \| #StoreStore");
	if (val) {
	while (lock->lock) {
	if (!--stuck) {
	if (shown++ <= 2)
	show(str, lock, caller);
	stuck = INIT_STUCK;
	}
	membar("#LoadLoad");
	}
	goto again;
	}
	lock->owner_pc = ((unsigned int)caller);
	lock->owner_cpu = cpu;
	current->thread.smp_lock_count++;
	current->thread.smp_lock_pc = ((unsigned int)caller);

	put_cpu();
	}

	int _do_spin_trylock(spinlock_t *lock)
	{
	unsigned long val, caller;
	int cpu = get_cpu();

	GET_CALLER(caller);
	__asm__ __volatile__("ldstub [%1], %0"
	: "=r" (val)
	: "r" (&(lock->lock))
	: "memory");
	membar("#StoreLoad \| #StoreStore");
	if (!val) {
	lock->owner_pc = ((unsigned int)caller);
	lock->owner_cpu = cpu;
	current->thread.smp_lock_count++;
	current->thread.smp_lock_pc = ((unsigned int)caller);
	}

	put_cpu();

	return val == 0;
	}

	void _do_spin_unlock(spinlock_t *lock)
	{
	lock->owner_pc = 0;
	lock->owner_cpu = NO_PROC_ID;
	membar("#StoreStore \| #LoadStore");
	lock->lock = 0;
	current->thread.smp_lock_count--;
	}

	/* Keep INIT_STUCK the same... */

	void _do_read_lock (rwlock_t rw, char str)
	{
	unsigned long caller, 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) {
	if (!--stuck) {
	if (shown++ <= 2)
	show_read(str, rw, caller);
	stuck = INIT_STUCK;
	}
	membar("#LoadLoad");
	}
	/* Try once to increment the counter. */
	__asm__ __volatile__(
	" ldx [%0], %%g1\n"
	" brlz,a,pn %%g1, 2f\n"
	" mov 1, %0\n"
	" add %%g1, 1, %%g7\n"
	" casx [%0], %%g1, %%g7\n"
	" sub %%g1, %%g7, %0\n"
	"2:" : "=r" (val)
	: "0" (&(rw->lock))
	: "g1", "g7", "memory");
	membar("#StoreLoad \| #StoreStore");
	if (val)
	goto wlock_again;
	rw->reader_pc[cpu] = ((unsigned int)caller);
	current->thread.smp_lock_count++;
	current->thread.smp_lock_pc = ((unsigned int)caller);

	put_cpu();
	}

	void _do_read_unlock (rwlock_t rw, char str)
	{
	unsigned long caller, 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--;
	runlock_again:
	/* Spin trying to decrement the counter using casx. */
	__asm__ __volatile__(
	" membar #StoreLoad \| #LoadLoad\n"
	" ldx [%0], %%g1\n"
	" sub %%g1, 1, %%g7\n"
	" casx [%0], %%g1, %%g7\n"
	" membar #StoreLoad \| #StoreStore\n"
	" sub %%g1, %%g7, %0\n"
	: "=r" (val)
	: "0" (&(rw->lock))
	: "g1", "g7", "memory");
	if (val) {
	if (!--stuck) {
	if (shown++ <= 2)
	show_read(str, rw, caller);
	stuck = INIT_STUCK;
	}
	goto runlock_again;
	}

	put_cpu();
	}

	void _do_write_lock (rwlock_t rw, char str)
	{
	unsigned long caller, 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) {
	if (!--stuck) {
	if (shown++ <= 2)
	show_write(str, rw, caller);
	stuck = INIT_STUCK;
	}
	membar("#LoadLoad");
	}

	/* Try to acuire the write bit. */
	__asm__ __volatile__(
	" mov 1, %%g3\n"
	" sllx %%g3, 63, %%g3\n"
	" ldx [%0], %%g1\n"
	" brlz,pn %%g1, 1f\n"
	" or %%g1, %%g3, %%g7\n"
	" casx [%0], %%g1, %%g7\n"
	" membar #StoreLoad \| #StoreStore\n"
	" ba,pt %%xcc, 2f\n"
	" sub %%g1, %%g7, %0\n"
	"1: mov 1, %0\n"
	"2:" : "=r" (val)
	: "0" (&(rw->lock))
	: "g3", "g1", "g7", "memory");
	if (val) {
	/* We couldn't get the write bit. */
	if (!--stuck) {
	if (shown++ <= 2)
	show_write(str, rw, caller);
	stuck = INIT_STUCK;
	}
	goto wlock_again;
	}
	if ((rw->lock & ((1UL<<63)-1UL)) != 0UL) {
	/* Readers still around, drop the write
	* lock, spin, and try again.
	*/
	if (!--stuck) {
	if (shown++ <= 2)
	show_write(str, rw, caller);
	stuck = INIT_STUCK;
	}
	__asm__ __volatile__(
	" mov 1, %%g3\n"
	" sllx %%g3, 63, %%g3\n"
	"1: ldx [%0], %%g1\n"
	" andn %%g1, %%g3, %%g7\n"
	" casx [%0], %%g1, %%g7\n"
	" cmp %%g1, %%g7\n"
	" membar #StoreLoad \| #StoreStore\n"
	" bne,pn %%xcc, 1b\n"
	" nop"
	: /* no outputs */
	: "r" (&(rw->lock))
	: "g3", "g1", "g7", "cc", "memory");
	while(rw->lock != 0) {
	if (!--stuck) {
	if (shown++ <= 2)
	show_write(str, rw, caller);
	stuck = INIT_STUCK;
	}
	membar("#LoadLoad");
	}
	goto wlock_again;
	}

	/* We have it, say who we are. */
	rw->writer_pc = ((unsigned int)caller);
	rw->writer_cpu = cpu;
	current->thread.smp_lock_count++;
	current->thread.smp_lock_pc = ((unsigned int)caller);

	put_cpu();
	}

	void _do_write_unlock(rwlock_t *rw)
	{
	unsigned long caller, 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;
	current->thread.smp_lock_count--;
	wlock_again:
	__asm__ __volatile__(
	" membar #StoreLoad \| #LoadLoad\n"
	" mov 1, %%g3\n"
	" sllx %%g3, 63, %%g3\n"
	" ldx [%0], %%g1\n"
	" andn %%g1, %%g3, %%g7\n"
	" casx [%0], %%g1, %%g7\n"
	" membar #StoreLoad \| #StoreStore\n"
	" sub %%g1, %%g7, %0\n"
	: "=r" (val)
	: "0" (&(rw->lock))
	: "g3", "g1", "g7", "memory");
	if (val) {
	if (!--stuck) {
	if (shown++ <= 2)
	show_write("write_unlock", rw, caller);
	stuck = INIT_STUCK;
	}
	goto wlock_again;
	}
	}

	int _do_write_trylock (rwlock_t rw, char str)
	{
	unsigned long caller, val;
	int cpu = get_cpu();

	GET_CALLER(caller);

	/* Try to acuire the write bit. */
	__asm__ __volatile__(
	" mov 1, %%g3\n"
	" sllx %%g3, 63, %%g3\n"
	" ldx [%0], %%g1\n"
	" brlz,pn %%g1, 1f\n"
	" or %%g1, %%g3, %%g7\n"
	" casx [%0], %%g1, %%g7\n"
	" membar #StoreLoad \| #StoreStore\n"
	" ba,pt %%xcc, 2f\n"
	" sub %%g1, %%g7, %0\n"
	"1: mov 1, %0\n"
	"2:" : "=r" (val)
	: "0" (&(rw->lock))
	: "g3", "g1", "g7", "memory");

	if (val) {
	put_cpu();
	return 0;
	}

	if ((rw->lock & ((1UL<<63)-1UL)) != 0UL) {
	/* Readers still around, drop the write
	* lock, return failure.
	*/
	__asm__ __volatile__(
	" mov 1, %%g3\n"
	" sllx %%g3, 63, %%g3\n"
	"1: ldx [%0], %%g1\n"
	" andn %%g1, %%g3, %%g7\n"
	" casx [%0], %%g1, %%g7\n"
	" cmp %%g1, %%g7\n"
	" membar #StoreLoad \| #StoreStore\n"
	" bne,pn %%xcc, 1b\n"
	" nop"
	: /* no outputs */
	: "r" (&(rw->lock))
	: "g3", "g1", "g7", "cc", "memory");

	put_cpu();

	return 0;
	}

	/* We have it, say who we are. */
	rw->writer_pc = ((unsigned int)caller);
	rw->writer_cpu = cpu;
	current->thread.smp_lock_count++;
	current->thread.smp_lock_pc = ((unsigned int)caller);

	put_cpu();

	return 1;
	}

	#endif /* CONFIG_SMP */