KVM: s390: Generalize access to SIGP controls

This patch generalizes access to the SIGP controls, which is a part of SCA.
This is to prepare for upcoming introduction of Extended SCA support.

Signed-off-by: Eugene (jno) Dvurechenski <jno@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

1 files changed, 45 insertions, 27 deletions

diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 6a75352f453c..2a4718af9dcf 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -34,6 +34,45 @@
 #define PFAULT_DONE 0x0680
 #define VIRTIO_PARAM 0x0d00
 
+/* handle external calls via sigp interpretation facility */
+static int sca_ext_call_pending(struct kvm_vcpu *vcpu, int *src_id)
+{
+        struct sca_block *sca = vcpu->kvm->arch.sca;
+        uint8_t sigp_ctrl = sca->cpu[vcpu->vcpu_id].sigp_ctrl;
+
+        if (src_id)
+                *src_id = sigp_ctrl & SIGP_CTRL_SCN_MASK;
+
+        return sigp_ctrl & SIGP_CTRL_C &&
+                atomic_read(&vcpu->arch.sie_block->cpuflags) &
+                        CPUSTAT_ECALL_PEND;
+}
+
+static int sca_inject_ext_call(struct kvm_vcpu *vcpu, int src_id)
+{
+        struct sca_block *sca = vcpu->kvm->arch.sca;
+        uint8_t *sigp_ctrl = &(sca->cpu[vcpu->vcpu_id].sigp_ctrl);
+        uint8_t new_val = SIGP_CTRL_C | (src_id & SIGP_CTRL_SCN_MASK);
+        uint8_t old_val = *sigp_ctrl & ~SIGP_CTRL_C;
+
+        if (cmpxchg(sigp_ctrl, old_val, new_val) != old_val) {
+                /* another external call is pending */
+                return -EBUSY;
+        }
+        atomic_or(CPUSTAT_ECALL_PEND, &vcpu->arch.sie_block->cpuflags);
+        return 0;
+}
+
+static void sca_clear_ext_call(struct kvm_vcpu *vcpu)
+{
+        struct sca_block *sca = vcpu->kvm->arch.sca;
+        struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
+        uint8_t *sigp_ctrl = &(sca->cpu[vcpu->vcpu_id].sigp_ctrl);
+
+        atomic_andnot(CPUSTAT_ECALL_PEND, li->cpuflags);
+        *sigp_ctrl = 0;
+}
+
 int psw_extint_disabled(struct kvm_vcpu *vcpu)
 {
         return !(vcpu->arch.sie_block->gpsw.mask & PSW_MASK_EXT);
@@ -792,13 +831,11 @@ static const deliver_irq_t deliver_irq_funcs[] = {
 int kvm_s390_ext_call_pending(struct kvm_vcpu *vcpu)
 {
         struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
-        uint8_t sigp_ctrl = vcpu->kvm->arch.sca->cpu[vcpu->vcpu_id].sigp_ctrl;
 
         if (!sclp.has_sigpif)
                 return test_bit(IRQ_PEND_EXT_EXTERNAL, &li->pending_irqs);
 
-        return (sigp_ctrl & SIGP_CTRL_C) &&
-               (atomic_read(&vcpu->arch.sie_block->cpuflags) & CPUSTAT_ECALL_PEND);
+        return sca_ext_call_pending(vcpu, NULL);
 }
 
 int kvm_s390_vcpu_has_irq(struct kvm_vcpu *vcpu, int exclude_stop)
@@ -909,9 +946,7 @@ void kvm_s390_clear_local_irqs(struct kvm_vcpu *vcpu)
         memset(&li->irq, 0, sizeof(li->irq));
         spin_unlock(&li->lock);
 
-        /* clear pending external calls set by sigp interpretation facility */
-        atomic_andnot(CPUSTAT_ECALL_PEND, li->cpuflags);
-        vcpu->kvm->arch.sca->cpu[vcpu->vcpu_id].sigp_ctrl = 0;
+        sca_clear_ext_call(vcpu);
 }
 
 int __must_check kvm_s390_deliver_pending_interrupts(struct kvm_vcpu *vcpu)
@@ -1003,21 +1038,6 @@ static int __inject_pfault_init(struct kvm_vcpu *vcpu, struct kvm_s390_irq *irq)
         return 0;
 }
 
-static int __inject_extcall_sigpif(struct kvm_vcpu *vcpu, uint16_t src_id)
-{
-        unsigned char new_val, old_val;
-        uint8_t *sigp_ctrl = &vcpu->kvm->arch.sca->cpu[vcpu->vcpu_id].sigp_ctrl;
-
-        new_val = SIGP_CTRL_C | (src_id & SIGP_CTRL_SCN_MASK);
-        old_val = *sigp_ctrl & ~SIGP_CTRL_C;
-        if (cmpxchg(sigp_ctrl, old_val, new_val) != old_val) {
-                /* another external call is pending */
-                return -EBUSY;
-        }
-        atomic_or(CPUSTAT_ECALL_PEND, &vcpu->arch.sie_block->cpuflags);
-        return 0;
-}
-
 static int __inject_extcall(struct kvm_vcpu *vcpu, struct kvm_s390_irq *irq)
 {
         struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
@@ -1034,7 +1054,7 @@ static int __inject_extcall(struct kvm_vcpu *vcpu, struct kvm_s390_irq *irq)
                 return -EINVAL;
 
         if (sclp.has_sigpif)
-                return __inject_extcall_sigpif(vcpu, src_id);
+                return sca_inject_ext_call(vcpu, src_id);
 
         if (test_and_set_bit(IRQ_PEND_EXT_EXTERNAL, &li->pending_irqs))
                 return -EBUSY;
@@ -2203,7 +2223,7 @@ static void store_local_irq(struct kvm_s390_local_interrupt *li,
 
 int kvm_s390_get_irq_state(struct kvm_vcpu *vcpu, __u8 __user *buf, int len)
 {
-        uint8_t sigp_ctrl = vcpu->kvm->arch.sca->cpu[vcpu->vcpu_id].sigp_ctrl;
+        int scn;
         unsigned long sigp_emerg_pending[BITS_TO_LONGS(KVM_MAX_VCPUS)];
         struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
         unsigned long pending_irqs;
@@ -2243,14 +2263,12 @@ int kvm_s390_get_irq_state(struct kvm_vcpu *vcpu, __u8 __user *buf, int len)
                 }
         }
 
-        if ((sigp_ctrl & SIGP_CTRL_C) &&
-            (atomic_read(&vcpu->arch.sie_block->cpuflags) &
-             CPUSTAT_ECALL_PEND)) {
+        if (sca_ext_call_pending(vcpu, &scn)) {
                 if (n + sizeof(irq) > len)
                         return -ENOBUFS;
                 memset(&irq, 0, sizeof(irq));
                 irq.type = KVM_S390_INT_EXTERNAL_CALL;
-                irq.u.extcall.code = sigp_ctrl & SIGP_CTRL_SCN_MASK;
+                irq.u.extcall.code = scn;
                 if (copy_to_user(&buf[n], &irq, sizeof(irq)))
                         return -EFAULT;
                 n += sizeof(irq);