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Commit 81533803 authored by Martin Schwidefsky's avatar Martin Schwidefsky
Browse files

s390/spinlock: use the cpu number +1 as spinlock value 



The queued spinlock code will come out simpler if the encoding of
the CPU that holds the spinlock is (cpu+1) instead of (~cpu).

Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 1887aa07

arch/s390/include/asm/spinlock.h

+1 −1
Original line number Diff line number Diff line
@@ -48,7 +48,7 @@ static inline void arch_spin_relax(arch_spinlock_t *lock) 


static inline u32 arch_spin_lockval(int cpu)

{

	return ~cpu;

	return cpu + 1;

}



static inline int arch_spin_value_unlocked(arch_spinlock_t lock)

arch/s390/lib/spinlock.c

+16 −16
Original line number Diff line number Diff line
@@ -67,8 +67,8 @@ void arch_spin_lock_wait(arch_spinlock_t *lp) 


	/* Pass the virtual CPU to the lock holder if it is not running */

	owner = arch_load_niai4(&lp->lock);

	if (owner && arch_vcpu_is_preempted(~owner))

		smp_yield_cpu(~owner);

	if (owner && arch_vcpu_is_preempted(owner - 1))

		smp_yield_cpu(owner - 1);



	count = spin_retry;

	while (1) {
@@ -87,8 +87,8 @@ void arch_spin_lock_wait(arch_spinlock_t *lp) 
		 * yield the CPU unconditionally. For LPAR rely on the

		 * sense running status.

		 */

		if (!MACHINE_IS_LPAR || arch_vcpu_is_preempted(~owner))

			smp_yield_cpu(~owner);

		if (!MACHINE_IS_LPAR || arch_vcpu_is_preempted(owner - 1))

			smp_yield_cpu(owner - 1);

	}

}

EXPORT_SYMBOL(arch_spin_lock_wait);
@@ -102,8 +102,8 @@ void arch_spin_lock_wait_flags(arch_spinlock_t *lp, unsigned long flags) 


	/* Pass the virtual CPU to the lock holder if it is not running */

	owner = arch_load_niai4(&lp->lock);

	if (owner && arch_vcpu_is_preempted(~owner))

		smp_yield_cpu(~owner);

	if (owner && arch_vcpu_is_preempted(owner - 1))

		smp_yield_cpu(owner - 1);



	count = spin_retry;

	while (1) {
@@ -124,8 +124,8 @@ void arch_spin_lock_wait_flags(arch_spinlock_t *lp, unsigned long flags) 
		 * yield the CPU unconditionally. For LPAR rely on the

		 * sense running status.

		 */

		if (!MACHINE_IS_LPAR || arch_vcpu_is_preempted(~owner))

			smp_yield_cpu(~owner);

		if (!MACHINE_IS_LPAR || arch_vcpu_is_preempted(owner - 1))

			smp_yield_cpu(owner - 1);

	}

}

EXPORT_SYMBOL(arch_spin_lock_wait_flags);
@@ -158,8 +158,8 @@ void _raw_read_lock_wait(arch_rwlock_t *rw) 
	owner = 0;

	while (1) {

		if (count-- <= 0) {

			if (owner && arch_vcpu_is_preempted(~owner))

				smp_yield_cpu(~owner);

			if (owner && arch_vcpu_is_preempted(owner - 1))

				smp_yield_cpu(owner - 1);

			count = spin_retry;

		}

		old = ACCESS_ONCE(rw->lock);
@@ -198,8 +198,8 @@ void _raw_write_lock_wait(arch_rwlock_t *rw, int prev) 
	owner = 0;

	while (1) {

		if (count-- <= 0) {

			if (owner && arch_vcpu_is_preempted(~owner))

				smp_yield_cpu(~owner);

			if (owner && arch_vcpu_is_preempted(owner - 1))

				smp_yield_cpu(owner - 1);

			count = spin_retry;

		}

		old = ACCESS_ONCE(rw->lock);
@@ -226,8 +226,8 @@ void _raw_write_lock_wait(arch_rwlock_t *rw) 
	owner = 0;

	while (1) {

		if (count-- <= 0) {

			if (owner && arch_vcpu_is_preempted(~owner))

				smp_yield_cpu(~owner);

			if (owner && arch_vcpu_is_preempted(owner - 1))

				smp_yield_cpu(owner - 1);

			count = spin_retry;

		}

		old = ACCESS_ONCE(rw->lock);
@@ -265,8 +265,8 @@ void arch_lock_relax(int cpu) 
{

	if (!cpu)

		return;

	if (MACHINE_IS_LPAR && !arch_vcpu_is_preempted(~cpu))

	if (MACHINE_IS_LPAR && !arch_vcpu_is_preempted(cpu - 1))

		return;

	smp_yield_cpu(~cpu);

	smp_yield_cpu(cpu - 1);

}

EXPORT_SYMBOL(arch_lock_relax);