* 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);
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;
}
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)