KVM: s390: Introduce new structures

This patch adds new structures and updates some existing ones to
provide the base for Extended SCA functionality.

The old sca_* structures were renamed to bsca_* to keep things uniform.

The access to fields of SIGP controls were turned into bitfields instead
of hardcoded bitmasks.

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

1 files changed, 19 insertions, 12 deletions

diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 2a4718af9dcf..aa221a48cc7c 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -37,25 +37,32 @@
 /* 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;
+        struct bsca_block *sca = vcpu->kvm->arch.sca;
+        union bsca_sigp_ctrl sigp_ctrl = sca->cpu[vcpu->vcpu_id].sigp_ctrl;
 
         if (src_id)
-                *src_id = sigp_ctrl & SIGP_CTRL_SCN_MASK;
+                *src_id = sigp_ctrl.scn;
 
-        return sigp_ctrl & SIGP_CTRL_C &&
+        return 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;
+        int expect, rc;
+        struct bsca_block *sca = vcpu->kvm->arch.sca;
+        union bsca_sigp_ctrl *sigp_ctrl = &(sca->cpu[vcpu->vcpu_id].sigp_ctrl);
+        union bsca_sigp_ctrl new_val = {0}, old_val = *sigp_ctrl;
 
-        if (cmpxchg(sigp_ctrl, old_val, new_val) != old_val) {
+        new_val.scn = src_id;
+        new_val.c = 1;
+        old_val.c = 0;
+
+        expect = old_val.value;
+        rc = cmpxchg(&sigp_ctrl->value, old_val.value, new_val.value);
+
+        if (rc != expect) {
                 /* another external call is pending */
                 return -EBUSY;
         }
@@ -65,12 +72,12 @@ static int sca_inject_ext_call(struct kvm_vcpu *vcpu, int src_id)
 
 static void sca_clear_ext_call(struct kvm_vcpu *vcpu)
 {
-        struct sca_block *sca = vcpu->kvm->arch.sca;
+        struct bsca_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);
+        union bsca_sigp_ctrl *sigp_ctrl = &(sca->cpu[vcpu->vcpu_id].sigp_ctrl);
 
         atomic_andnot(CPUSTAT_ECALL_PEND, li->cpuflags);
-        *sigp_ctrl = 0;
+        sigp_ctrl->value = 0;
 }
 
 int psw_extint_disabled(struct kvm_vcpu *vcpu)