Merge tag 'iwlwifi-next-for-kalle-2014-12-30' of https://git.kernel.org/pub/scm/linux...

[cascardo/linux.git] / arch / powerpc / kvm / book3s_xics.c

diff --git a/arch/powerpc/kvm/book3s_xics.c b/arch/powerpc/kvm/book3s_xics.c
index eaeb780..807351f 100644 (file)
--- a/arch/powerpc/kvm/book3s_xics.c
+++ b/arch/powerpc/kvm/book3s_xics.c
@@ -613,10 +613,25 @@ static noinline int kvmppc_h_ipi(struct kvm_vcpu *vcpu, unsigned long server,
         * there might be a previously-rejected interrupt needing
         * to be resent.
         *
+        * ICP state: Check_IPI
+        *
         * If the CPPR is less favored, then we might be replacing
-        * an interrupt, and thus need to possibly reject it as in
+        * an interrupt, and thus need to possibly reject it.
         *
-        * ICP state: Check_IPI
+        * ICP State: IPI
+        *
+        * Besides rejecting any pending interrupts, we also
+        * update XISR and pending_pri to mark IPI as pending.
+        *
+        * PAPR does not describe this state, but if the MFRR is being
+        * made less favored than its earlier value, there might be
+        * a previously-rejected interrupt needing to be resent.
+        * Ideally, we would want to resend only if
+        *      prio(pending_interrupt) < mfrr &&
+        *      prio(pending_interrupt) < cppr
+        * where pending interrupt is the one that was rejected. But
+        * we don't have that state, so we simply trigger a resend
+        * whenever the MFRR is made less favored.
         */
        do {
                old_state = new_state = ACCESS_ONCE(icp->state);
@@ -629,13 +644,14 @@ static noinline int kvmppc_h_ipi(struct kvm_vcpu *vcpu, unsigned long server,
                resend = false;
                if (mfrr < new_state.cppr) {
                        /* Reject a pending interrupt if not an IPI */
-                       if (mfrr <= new_state.pending_pri)
+                       if (mfrr <= new_state.pending_pri) {
                                reject = new_state.xisr;
-                       new_state.pending_pri = mfrr;
-                       new_state.xisr = XICS_IPI;
+                               new_state.pending_pri = mfrr;
+                               new_state.xisr = XICS_IPI;
+                       }
                }
 
-               if (mfrr > old_state.mfrr && mfrr > new_state.cppr) {
+               if (mfrr > old_state.mfrr) {
                        resend = new_state.need_resend;
                        new_state.need_resend = 0;
                }
@@ -789,7 +805,7 @@ static noinline int kvmppc_xics_rm_complete(struct kvm_vcpu *vcpu, u32 hcall)
        if (icp->rm_action & XICS_RM_KICK_VCPU)
                kvmppc_fast_vcpu_kick(icp->rm_kick_target);
        if (icp->rm_action & XICS_RM_CHECK_RESEND)
-               icp_check_resend(xics, icp);
+               icp_check_resend(xics, icp->rm_resend_icp);
        if (icp->rm_action & XICS_RM_REJECT)
                icp_deliver_irq(xics, icp, icp->rm_reject);
        if (icp->rm_action & XICS_RM_NOTIFY_EOI)