[GIT PULL 2/9] KVM: s390: remove _bh locking from local_int.lock

Christian Borntraeger
2014-07-21T19:14:18Z

From: David Hildenbrand <dahi@linux.vnet.ibm.com>

local_int.lock is not used in a bottom-half handler anymore, therefore we can
turn it into an ordinary spin_lock at all occurrences.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
arch/s390/kvm/interrupt.c | 32 ++++++++++++++++----------------
arch/s390/kvm/kvm-s390.c | 4 ++--
arch/s390/kvm/sigp.c | 20 ++++++++++----------
3 files changed, 28 insertions(+), 28 deletions(-)

diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 5fd11ce..86575b4 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -544,13 +544,13 @@ int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu)
int rc = 0;

if (atomic_read(&li->active)) {
- spin_lock_bh(&li->lock);
+ spin_lock(&li->lock);
list_for_each_entry(inti, &li->list, list)
if (__interrupt_is_deliverable(vcpu, inti)) {
rc = 1;
break;
}
- spin_unlock_bh(&li->lock);
+ spin_unlock(&li->lock);
}

if ((!rc) && atomic_read(&fi->active)) {
@@ -645,13 +645,13 @@ void kvm_s390_clear_local_irqs(struct kvm_vcpu *vcpu)
struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
struct kvm_s390_interrupt_info *n, *inti = NULL;

- spin_lock_bh(&li->lock);
+ spin_lock(&li->lock);
list_for_each_entry_safe(inti, n, &li->list, list) {
list_del(&inti->list);
kfree(inti);
}
atomic_set(&li->active, 0);
- spin_unlock_bh(&li->lock);
+ spin_unlock(&li->lock);

/* clear pending external calls set by sigp interpretation facility */
atomic_clear_mask(CPUSTAT_ECALL_PEND, &vcpu->arch.sie_block->cpuflags);
@@ -670,7 +670,7 @@ void kvm_s390_deliver_pending_interrupts(struct kvm_vcpu *vcpu)
if (atomic_read(&li->active)) {
do {
deliver = 0;
- spin_lock_bh(&li->lock);
+ spin_lock(&li->lock);
list_for_each_entry_safe(inti, n, &li->list, list) {
if (__interrupt_is_deliverable(vcpu, inti)) {
list_del(&inti->list);
@@ -681,7 +681,7 @@ void kvm_s390_deliver_pending_interrupts(struct kvm_vcpu *vcpu)
}
if (list_empty(&li->list))
atomic_set(&li->active, 0);
- spin_unlock_bh(&li->lock);
+ spin_unlock(&li->lock);
if (deliver) {
__do_deliver_interrupt(vcpu, inti);
kfree(inti);
@@ -727,7 +727,7 @@ void kvm_s390_deliver_pending_machine_checks(struct kvm_vcpu *vcpu)
if (atomic_read(&li->active)) {
do {
deliver = 0;
- spin_lock_bh(&li->lock);
+ spin_lock(&li->lock);
list_for_each_entry_safe(inti, n, &li->list, list) {
if ((inti->type == KVM_S390_MCHK) &&
__interrupt_is_deliverable(vcpu, inti)) {
@@ -739,7 +739,7 @@ void kvm_s390_deliver_pending_machine_checks(struct kvm_vcpu *vcpu)
}
if (list_empty(&li->list))
atomic_set(&li->active, 0);
- spin_unlock_bh(&li->lock);
+ spin_unlock(&li->lock);
if (deliver) {
__do_deliver_interrupt(vcpu, inti);
kfree(inti);
@@ -786,11 +786,11 @@ int kvm_s390_inject_program_int(struct kvm_vcpu *vcpu, u16 code)

VCPU_EVENT(vcpu, 3, "inject: program check %d (from kernel)", code);
trace_kvm_s390_inject_vcpu(vcpu->vcpu_id, inti->type, code, 0, 1);
- spin_lock_bh(&li->lock);
+ spin_lock(&li->lock);
list_add(&inti->list, &li->list);
atomic_set(&li->active, 1);
BUG_ON(waitqueue_active(li->wq));
- spin_unlock_bh(&li->lock);
+ spin_unlock(&li->lock);
return 0;
}

@@ -811,11 +811,11 @@ int kvm_s390_inject_prog_irq(struct kvm_vcpu *vcpu,

inti->type = KVM_S390_PROGRAM_INT;
memcpy(&inti->pgm, pgm_info, sizeof(inti->pgm));
- spin_lock_bh(&li->lock);
+ spin_lock(&li->lock);
list_add(&inti->list, &li->list);
atomic_set(&li->active, 1);
BUG_ON(waitqueue_active(li->wq));
- spin_unlock_bh(&li->lock);
+ spin_unlock(&li->lock);
return 0;
}

@@ -903,12 +903,12 @@ static int __inject_vm(struct kvm *kvm, struct kvm_s390_interrupt_info *inti)
}
dst_vcpu = kvm_get_vcpu(kvm, sigcpu);
li = &dst_vcpu->arch.local_int;
- spin_lock_bh(&li->lock);
+ spin_lock(&li->lock);
atomic_set_mask(CPUSTAT_EXT_INT, li->cpuflags);
if (waitqueue_active(li->wq))
wake_up_interruptible(li->wq);
kvm_get_vcpu(kvm, sigcpu)->preempted = true;
- spin_unlock_bh(&li->lock);
+ spin_unlock(&li->lock);
unlock_fi:
spin_unlock(&fi->lock);
mutex_unlock(&kvm->lock);
@@ -1050,7 +1050,7 @@ int kvm_s390_inject_vcpu(struct kvm_vcpu *vcpu,

mutex_lock(&vcpu->kvm->lock);
li = &vcpu->arch.local_int;
- spin_lock_bh(&li->lock);
+ spin_lock(&li->lock);
if (inti->type == KVM_S390_PROGRAM_INT)
list_add(&inti->list, &li->list);
else
@@ -1062,7 +1062,7 @@ int kvm_s390_inject_vcpu(struct kvm_vcpu *vcpu,
if (waitqueue_active(&vcpu->wq))
wake_up_interruptible(&vcpu->wq);
vcpu->preempted = true;
- spin_unlock_bh(&li->lock);
+ spin_unlock(&li->lock);
mutex_unlock(&vcpu->kvm->lock);
return 0;
}
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index ecb1357..a7bda18 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -1522,13 +1522,13 @@ void kvm_s390_vcpu_stop(struct kvm_vcpu *vcpu)
online_vcpus = atomic_read(&vcpu->kvm->online_vcpus);

/* Need to lock access to action_bits to avoid a SIGP race condition */
- spin_lock_bh(&vcpu->arch.local_int.lock);
+ spin_lock(&vcpu->arch.local_int.lock);
atomic_set_mask(CPUSTAT_STOPPED, &vcpu->arch.sie_block->cpuflags);

/* SIGP STOP and SIGP STOP AND STORE STATUS has been fully processed */
vcpu->arch.local_int.action_bits &=
~(ACTION_STOP_ON_STOP | ACTION_STORE_ON_STOP);
- spin_unlock_bh(&vcpu->arch.local_int.lock);
+ spin_unlock(&vcpu->arch.local_int.lock);

__disable_ibs_on_vcpu(vcpu);

diff --git a/arch/s390/kvm/sigp.c b/arch/s390/kvm/sigp.c
index fd7fb5c..946992f 100644
--- a/arch/s390/kvm/sigp.c
+++ b/arch/s390/kvm/sigp.c
@@ -135,7 +135,7 @@ static int __inject_sigp_stop(struct kvm_s390_local_interrupt *li, int action)
return -ENOMEM;
inti->type = KVM_S390_SIGP_STOP;

- spin_lock_bh(&li->lock);
+ spin_lock(&li->lock);
if (li->action_bits & ACTION_STOP_ON_STOP) {
/* another SIGP STOP is pending */
rc = SIGP_CC_BUSY;
@@ -154,7 +154,7 @@ static int __inject_sigp_stop(struct kvm_s390_local_interrupt *li, int action)
if (waitqueue_active(li->wq))
wake_up_interruptible(li->wq);
out:
- spin_unlock_bh(&li->lock);
+ spin_unlock(&li->lock);

return rc;
}
@@ -243,7 +243,7 @@ static int __sigp_set_prefix(struct kvm_vcpu *vcpu, u16 cpu_addr, u32 address,
if (!inti)
return SIGP_CC_BUSY;

- spin_lock_bh(&li->lock);
+ spin_lock(&li->lock);
/* cpu must be in stopped state */
if (!(atomic_read(li->cpuflags) & CPUSTAT_STOPPED)) {
*reg &= 0xffffffff00000000UL;
@@ -264,7 +264,7 @@ static int __sigp_set_prefix(struct kvm_vcpu *vcpu, u16 cpu_addr, u32 address,

VCPU_EVENT(vcpu, 4, "set prefix of cpu %02x to %x", cpu_addr, address);
out_li:
- spin_unlock_bh(&li->lock);
+ spin_unlock(&li->lock);
return rc;
}

@@ -280,9 +280,9 @@ static int __sigp_store_status_at_addr(struct kvm_vcpu *vcpu, u16 cpu_id,
if (!dst_vcpu)
return SIGP_CC_NOT_OPERATIONAL;

- spin_lock_bh(&dst_vcpu->arch.local_int.lock);
+ spin_lock(&dst_vcpu->arch.local_int.lock);
flags = atomic_read(dst_vcpu->arch.local_int.cpuflags);
- spin_unlock_bh(&dst_vcpu->arch.local_int.lock);
+ spin_unlock(&dst_vcpu->arch.local_int.lock);
if (!(flags & CPUSTAT_STOPPED)) {
*reg &= 0xffffffff00000000UL;
*reg |= SIGP_STATUS_INCORRECT_STATE;
@@ -343,10 +343,10 @@ static int sigp_check_callable(struct kvm_vcpu *vcpu, u16 cpu_addr)
if (!dst_vcpu)
return SIGP_CC_NOT_OPERATIONAL;
li = &dst_vcpu->arch.local_int;
- spin_lock_bh(&li->lock);
+ spin_lock(&li->lock);
if (li->action_bits & ACTION_STOP_ON_STOP)
rc = SIGP_CC_BUSY;
- spin_unlock_bh(&li->lock);
+ spin_unlock(&li->lock);

return rc;
}
@@ -466,11 +466,11 @@ int kvm_s390_handle_sigp_pei(struct kvm_vcpu *vcpu)
dest_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
BUG_ON(dest_vcpu == NULL);

- spin_lock_bh(&dest_vcpu->arch.local_int.lock);
+ spin_lock(&dest_vcpu->arch.local_int.lock);
if (waitqueue_active(&dest_vcpu->wq))
wake_up_interruptible(&dest_vcpu->wq);
dest_vcpu->preempted = true;
- spin_unlock_bh(&dest_vcpu->arch.local_int.lock);
+ spin_unlock(&dest_vcpu->arch.local_int.lock);

kvm_s390_set_psw_cc(vcpu, SIGP_CC_ORDER_CODE_ACCEPTED);
return 0;
--
1.8.4.2