648 lines
16 KiB
C
648 lines
16 KiB
C
/*
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* Copyright 2017 Benjamin Herrenschmidt, IBM Corporation
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License, version 2, as
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* published by the Free Software Foundation.
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*/
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/* File to be included by other .c files */
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#define XGLUE(a,b) a##b
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#define GLUE(a,b) XGLUE(a,b)
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/* Dummy interrupt used when taking interrupts out of a queue in H_CPPR */
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#define XICS_DUMMY 1
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static void GLUE(X_PFX,ack_pending)(struct kvmppc_xive_vcpu *xc)
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{
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u8 cppr;
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u16 ack;
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/*
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* Ensure any previous store to CPPR is ordered vs.
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* the subsequent loads from PIPR or ACK.
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*/
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eieio();
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/* Perform the acknowledge OS to register cycle. */
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ack = be16_to_cpu(__x_readw(__x_tima + TM_SPC_ACK_OS_REG));
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/* Synchronize subsequent queue accesses */
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mb();
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/* XXX Check grouping level */
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/* Anything ? */
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if (!((ack >> 8) & TM_QW1_NSR_EO))
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return;
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/* Grab CPPR of the most favored pending interrupt */
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cppr = ack & 0xff;
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if (cppr < 8)
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xc->pending |= 1 << cppr;
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#ifdef XIVE_RUNTIME_CHECKS
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/* Check consistency */
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if (cppr >= xc->hw_cppr)
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pr_warn("KVM-XIVE: CPU %d odd ack CPPR, got %d at %d\n",
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smp_processor_id(), cppr, xc->hw_cppr);
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#endif
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/*
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* Update our image of the HW CPPR. We don't yet modify
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* xc->cppr, this will be done as we scan for interrupts
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* in the queues.
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*/
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xc->hw_cppr = cppr;
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}
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static u8 GLUE(X_PFX,esb_load)(struct xive_irq_data *xd, u32 offset)
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{
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u64 val;
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if (xd->flags & XIVE_IRQ_FLAG_SHIFT_BUG)
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offset |= offset << 4;
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val =__x_readq(__x_eoi_page(xd) + offset);
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#ifdef __LITTLE_ENDIAN__
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val >>= 64-8;
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#endif
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return (u8)val;
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}
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static void GLUE(X_PFX,source_eoi)(u32 hw_irq, struct xive_irq_data *xd)
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{
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/* If the XIVE supports the new "store EOI facility, use it */
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if (xd->flags & XIVE_IRQ_FLAG_STORE_EOI)
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__x_writeq(0, __x_eoi_page(xd) + XIVE_ESB_STORE_EOI);
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else if (hw_irq && xd->flags & XIVE_IRQ_FLAG_EOI_FW)
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opal_int_eoi(hw_irq);
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else if (xd->flags & XIVE_IRQ_FLAG_LSI) {
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/*
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* For LSIs the HW EOI cycle is used rather than PQ bits,
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* as they are automatically re-triggred in HW when still
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* pending.
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*/
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__x_readq(__x_eoi_page(xd) + XIVE_ESB_LOAD_EOI);
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} else {
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uint64_t eoi_val;
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/*
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* Otherwise for EOI, we use the special MMIO that does
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* a clear of both P and Q and returns the old Q,
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* except for LSIs where we use the "EOI cycle" special
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* load.
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*
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* This allows us to then do a re-trigger if Q was set
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* rather than synthetizing an interrupt in software
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*/
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eoi_val = GLUE(X_PFX,esb_load)(xd, XIVE_ESB_SET_PQ_00);
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/* Re-trigger if needed */
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if ((eoi_val & 1) && __x_trig_page(xd))
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__x_writeq(0, __x_trig_page(xd));
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}
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}
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enum {
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scan_fetch,
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scan_poll,
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scan_eoi,
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};
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static u32 GLUE(X_PFX,scan_interrupts)(struct kvmppc_xive_vcpu *xc,
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u8 pending, int scan_type)
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{
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u32 hirq = 0;
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u8 prio = 0xff;
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/* Find highest pending priority */
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while ((xc->mfrr != 0xff || pending != 0) && hirq == 0) {
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struct xive_q *q;
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u32 idx, toggle;
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__be32 *qpage;
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/*
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* If pending is 0 this will return 0xff which is what
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* we want
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*/
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prio = ffs(pending) - 1;
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/*
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* If the most favoured prio we found pending is less
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* favored (or equal) than a pending IPI, we return
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* the IPI instead.
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*
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* Note: If pending was 0 and mfrr is 0xff, we will
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* not spurriously take an IPI because mfrr cannot
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* then be smaller than cppr.
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*/
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if (prio >= xc->mfrr && xc->mfrr < xc->cppr) {
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prio = xc->mfrr;
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hirq = XICS_IPI;
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break;
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}
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/* Don't scan past the guest cppr */
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if (prio >= xc->cppr || prio > 7)
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break;
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/* Grab queue and pointers */
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q = &xc->queues[prio];
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idx = q->idx;
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toggle = q->toggle;
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/*
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* Snapshot the queue page. The test further down for EOI
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* must use the same "copy" that was used by __xive_read_eq
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* since qpage can be set concurrently and we don't want
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* to miss an EOI.
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*/
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qpage = READ_ONCE(q->qpage);
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skip_ipi:
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/*
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* Try to fetch from the queue. Will return 0 for a
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* non-queueing priority (ie, qpage = 0).
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*/
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hirq = __xive_read_eq(qpage, q->msk, &idx, &toggle);
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/*
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* If this was a signal for an MFFR change done by
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* H_IPI we skip it. Additionally, if we were fetching
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* we EOI it now, thus re-enabling reception of a new
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* such signal.
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*
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* We also need to do that if prio is 0 and we had no
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* page for the queue. In this case, we have non-queued
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* IPI that needs to be EOId.
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*
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* This is safe because if we have another pending MFRR
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* change that wasn't observed above, the Q bit will have
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* been set and another occurrence of the IPI will trigger.
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*/
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if (hirq == XICS_IPI || (prio == 0 && !qpage)) {
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if (scan_type == scan_fetch)
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GLUE(X_PFX,source_eoi)(xc->vp_ipi,
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&xc->vp_ipi_data);
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/* Loop back on same queue with updated idx/toggle */
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#ifdef XIVE_RUNTIME_CHECKS
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WARN_ON(hirq && hirq != XICS_IPI);
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#endif
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if (hirq)
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goto skip_ipi;
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}
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/* If it's the dummy interrupt, continue searching */
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if (hirq == XICS_DUMMY)
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goto skip_ipi;
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/* If fetching, update queue pointers */
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if (scan_type == scan_fetch) {
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q->idx = idx;
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q->toggle = toggle;
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}
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/* Something found, stop searching */
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if (hirq)
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break;
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/* Clear the pending bit on the now empty queue */
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pending &= ~(1 << prio);
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/*
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* Check if the queue count needs adjusting due to
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* interrupts being moved away.
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*/
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if (atomic_read(&q->pending_count)) {
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int p = atomic_xchg(&q->pending_count, 0);
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if (p) {
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#ifdef XIVE_RUNTIME_CHECKS
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WARN_ON(p > atomic_read(&q->count));
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#endif
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atomic_sub(p, &q->count);
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}
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}
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}
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/* If we are just taking a "peek", do nothing else */
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if (scan_type == scan_poll)
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return hirq;
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/* Update the pending bits */
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xc->pending = pending;
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/*
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* If this is an EOI that's it, no CPPR adjustment done here,
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* all we needed was cleanup the stale pending bits and check
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* if there's anything left.
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*/
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if (scan_type == scan_eoi)
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return hirq;
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/*
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* If we found an interrupt, adjust what the guest CPPR should
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* be as if we had just fetched that interrupt from HW.
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*
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* Note: This can only make xc->cppr smaller as the previous
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* loop will only exit with hirq != 0 if prio is lower than
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* the current xc->cppr. Thus we don't need to re-check xc->mfrr
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* for pending IPIs.
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*/
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if (hirq)
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xc->cppr = prio;
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/*
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* If it was an IPI the HW CPPR might have been lowered too much
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* as the HW interrupt we use for IPIs is routed to priority 0.
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*
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* We re-sync it here.
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*/
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if (xc->cppr != xc->hw_cppr) {
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xc->hw_cppr = xc->cppr;
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__x_writeb(xc->cppr, __x_tima + TM_QW1_OS + TM_CPPR);
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}
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return hirq;
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}
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X_STATIC unsigned long GLUE(X_PFX,h_xirr)(struct kvm_vcpu *vcpu)
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{
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struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
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u8 old_cppr;
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u32 hirq;
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pr_devel("H_XIRR\n");
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xc->GLUE(X_STAT_PFX,h_xirr)++;
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/* First collect pending bits from HW */
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GLUE(X_PFX,ack_pending)(xc);
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/*
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* Cleanup the old-style bits if needed (they may have been
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* set by pull or an escalation interrupts).
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*/
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if (test_bit(BOOK3S_IRQPRIO_EXTERNAL, &vcpu->arch.pending_exceptions))
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clear_bit(BOOK3S_IRQPRIO_EXTERNAL_LEVEL,
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&vcpu->arch.pending_exceptions);
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pr_devel(" new pending=0x%02x hw_cppr=%d cppr=%d\n",
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xc->pending, xc->hw_cppr, xc->cppr);
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/* Grab previous CPPR and reverse map it */
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old_cppr = xive_prio_to_guest(xc->cppr);
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/* Scan for actual interrupts */
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hirq = GLUE(X_PFX,scan_interrupts)(xc, xc->pending, scan_fetch);
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pr_devel(" got hirq=0x%x hw_cppr=%d cppr=%d\n",
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hirq, xc->hw_cppr, xc->cppr);
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#ifdef XIVE_RUNTIME_CHECKS
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/* That should never hit */
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if (hirq & 0xff000000)
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pr_warn("XIVE: Weird guest interrupt number 0x%08x\n", hirq);
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#endif
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/*
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* XXX We could check if the interrupt is masked here and
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* filter it. If we chose to do so, we would need to do:
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*
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* if (masked) {
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* lock();
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* if (masked) {
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* old_Q = true;
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* hirq = 0;
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* }
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* unlock();
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* }
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*/
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/* Return interrupt and old CPPR in GPR4 */
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vcpu->arch.regs.gpr[4] = hirq | (old_cppr << 24);
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return H_SUCCESS;
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}
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X_STATIC unsigned long GLUE(X_PFX,h_ipoll)(struct kvm_vcpu *vcpu, unsigned long server)
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{
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struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
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u8 pending = xc->pending;
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u32 hirq;
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pr_devel("H_IPOLL(server=%ld)\n", server);
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xc->GLUE(X_STAT_PFX,h_ipoll)++;
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/* Grab the target VCPU if not the current one */
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if (xc->server_num != server) {
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vcpu = kvmppc_xive_find_server(vcpu->kvm, server);
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if (!vcpu)
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return H_PARAMETER;
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xc = vcpu->arch.xive_vcpu;
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/* Scan all priorities */
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pending = 0xff;
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} else {
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/* Grab pending interrupt if any */
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__be64 qw1 = __x_readq(__x_tima + TM_QW1_OS);
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u8 pipr = be64_to_cpu(qw1) & 0xff;
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if (pipr < 8)
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pending |= 1 << pipr;
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}
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hirq = GLUE(X_PFX,scan_interrupts)(xc, pending, scan_poll);
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/* Return interrupt and old CPPR in GPR4 */
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vcpu->arch.regs.gpr[4] = hirq | (xc->cppr << 24);
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return H_SUCCESS;
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}
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static void GLUE(X_PFX,push_pending_to_hw)(struct kvmppc_xive_vcpu *xc)
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{
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u8 pending, prio;
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pending = xc->pending;
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if (xc->mfrr != 0xff) {
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if (xc->mfrr < 8)
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pending |= 1 << xc->mfrr;
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else
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pending |= 0x80;
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}
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if (!pending)
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return;
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prio = ffs(pending) - 1;
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__x_writeb(prio, __x_tima + TM_SPC_SET_OS_PENDING);
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}
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static void GLUE(X_PFX,scan_for_rerouted_irqs)(struct kvmppc_xive *xive,
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struct kvmppc_xive_vcpu *xc)
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{
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unsigned int prio;
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/* For each priority that is now masked */
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for (prio = xc->cppr; prio < KVMPPC_XIVE_Q_COUNT; prio++) {
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struct xive_q *q = &xc->queues[prio];
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struct kvmppc_xive_irq_state *state;
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struct kvmppc_xive_src_block *sb;
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u32 idx, toggle, entry, irq, hw_num;
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struct xive_irq_data *xd;
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__be32 *qpage;
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u16 src;
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idx = q->idx;
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toggle = q->toggle;
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qpage = READ_ONCE(q->qpage);
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if (!qpage)
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continue;
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/* For each interrupt in the queue */
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for (;;) {
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entry = be32_to_cpup(qpage + idx);
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/* No more ? */
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if ((entry >> 31) == toggle)
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break;
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irq = entry & 0x7fffffff;
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/* Skip dummies and IPIs */
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if (irq == XICS_DUMMY || irq == XICS_IPI)
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goto next;
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sb = kvmppc_xive_find_source(xive, irq, &src);
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if (!sb)
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goto next;
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state = &sb->irq_state[src];
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/* Has it been rerouted ? */
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if (xc->server_num == state->act_server)
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goto next;
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/*
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* Allright, it *has* been re-routed, kill it from
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* the queue.
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*/
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qpage[idx] = cpu_to_be32((entry & 0x80000000) | XICS_DUMMY);
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/* Find the HW interrupt */
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kvmppc_xive_select_irq(state, &hw_num, &xd);
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/* If it's not an LSI, set PQ to 11 the EOI will force a resend */
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if (!(xd->flags & XIVE_IRQ_FLAG_LSI))
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GLUE(X_PFX,esb_load)(xd, XIVE_ESB_SET_PQ_11);
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/* EOI the source */
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GLUE(X_PFX,source_eoi)(hw_num, xd);
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next:
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idx = (idx + 1) & q->msk;
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if (idx == 0)
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toggle ^= 1;
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}
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}
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}
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X_STATIC int GLUE(X_PFX,h_cppr)(struct kvm_vcpu *vcpu, unsigned long cppr)
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{
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struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
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struct kvmppc_xive *xive = vcpu->kvm->arch.xive;
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u8 old_cppr;
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pr_devel("H_CPPR(cppr=%ld)\n", cppr);
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xc->GLUE(X_STAT_PFX,h_cppr)++;
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/* Map CPPR */
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cppr = xive_prio_from_guest(cppr);
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/* Remember old and update SW state */
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old_cppr = xc->cppr;
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xc->cppr = cppr;
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/*
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* Order the above update of xc->cppr with the subsequent
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* read of xc->mfrr inside push_pending_to_hw()
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*/
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smp_mb();
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if (cppr > old_cppr) {
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/*
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* We are masking less, we need to look for pending things
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* to deliver and set VP pending bits accordingly to trigger
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* a new interrupt otherwise we might miss MFRR changes for
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* which we have optimized out sending an IPI signal.
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*/
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GLUE(X_PFX,push_pending_to_hw)(xc);
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} else {
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/*
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* We are masking more, we need to check the queue for any
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* interrupt that has been routed to another CPU, take
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* it out (replace it with the dummy) and retrigger it.
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*
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* This is necessary since those interrupts may otherwise
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* never be processed, at least not until this CPU restores
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* its CPPR.
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*
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* This is in theory racy vs. HW adding new interrupts to
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* the queue. In practice this works because the interesting
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* cases are when the guest has done a set_xive() to move the
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* interrupt away, which flushes the xive, followed by the
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* target CPU doing a H_CPPR. So any new interrupt coming into
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* the queue must still be routed to us and isn't a source
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* of concern.
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*/
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GLUE(X_PFX,scan_for_rerouted_irqs)(xive, xc);
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}
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/* Apply new CPPR */
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xc->hw_cppr = cppr;
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__x_writeb(cppr, __x_tima + TM_QW1_OS + TM_CPPR);
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return H_SUCCESS;
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}
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X_STATIC int GLUE(X_PFX,h_eoi)(struct kvm_vcpu *vcpu, unsigned long xirr)
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{
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struct kvmppc_xive *xive = vcpu->kvm->arch.xive;
|
|
struct kvmppc_xive_src_block *sb;
|
|
struct kvmppc_xive_irq_state *state;
|
|
struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
|
|
struct xive_irq_data *xd;
|
|
u8 new_cppr = xirr >> 24;
|
|
u32 irq = xirr & 0x00ffffff, hw_num;
|
|
u16 src;
|
|
int rc = 0;
|
|
|
|
pr_devel("H_EOI(xirr=%08lx)\n", xirr);
|
|
|
|
xc->GLUE(X_STAT_PFX,h_eoi)++;
|
|
|
|
xc->cppr = xive_prio_from_guest(new_cppr);
|
|
|
|
/*
|
|
* IPIs are synthetized from MFRR and thus don't need
|
|
* any special EOI handling. The underlying interrupt
|
|
* used to signal MFRR changes is EOId when fetched from
|
|
* the queue.
|
|
*/
|
|
if (irq == XICS_IPI || irq == 0) {
|
|
/*
|
|
* This barrier orders the setting of xc->cppr vs.
|
|
* subsquent test of xc->mfrr done inside
|
|
* scan_interrupts and push_pending_to_hw
|
|
*/
|
|
smp_mb();
|
|
goto bail;
|
|
}
|
|
|
|
/* Find interrupt source */
|
|
sb = kvmppc_xive_find_source(xive, irq, &src);
|
|
if (!sb) {
|
|
pr_devel(" source not found !\n");
|
|
rc = H_PARAMETER;
|
|
/* Same as above */
|
|
smp_mb();
|
|
goto bail;
|
|
}
|
|
state = &sb->irq_state[src];
|
|
kvmppc_xive_select_irq(state, &hw_num, &xd);
|
|
|
|
state->in_eoi = true;
|
|
|
|
/*
|
|
* This barrier orders both setting of in_eoi above vs,
|
|
* subsequent test of guest_priority, and the setting
|
|
* of xc->cppr vs. subsquent test of xc->mfrr done inside
|
|
* scan_interrupts and push_pending_to_hw
|
|
*/
|
|
smp_mb();
|
|
|
|
again:
|
|
if (state->guest_priority == MASKED) {
|
|
arch_spin_lock(&sb->lock);
|
|
if (state->guest_priority != MASKED) {
|
|
arch_spin_unlock(&sb->lock);
|
|
goto again;
|
|
}
|
|
pr_devel(" EOI on saved P...\n");
|
|
|
|
/* Clear old_p, that will cause unmask to perform an EOI */
|
|
state->old_p = false;
|
|
|
|
arch_spin_unlock(&sb->lock);
|
|
} else {
|
|
pr_devel(" EOI on source...\n");
|
|
|
|
/* Perform EOI on the source */
|
|
GLUE(X_PFX,source_eoi)(hw_num, xd);
|
|
|
|
/* If it's an emulated LSI, check level and resend */
|
|
if (state->lsi && state->asserted)
|
|
__x_writeq(0, __x_trig_page(xd));
|
|
|
|
}
|
|
|
|
/*
|
|
* This barrier orders the above guest_priority check
|
|
* and spin_lock/unlock with clearing in_eoi below.
|
|
*
|
|
* It also has to be a full mb() as it must ensure
|
|
* the MMIOs done in source_eoi() are completed before
|
|
* state->in_eoi is visible.
|
|
*/
|
|
mb();
|
|
state->in_eoi = false;
|
|
bail:
|
|
|
|
/* Re-evaluate pending IRQs and update HW */
|
|
GLUE(X_PFX,scan_interrupts)(xc, xc->pending, scan_eoi);
|
|
GLUE(X_PFX,push_pending_to_hw)(xc);
|
|
pr_devel(" after scan pending=%02x\n", xc->pending);
|
|
|
|
/* Apply new CPPR */
|
|
xc->hw_cppr = xc->cppr;
|
|
__x_writeb(xc->cppr, __x_tima + TM_QW1_OS + TM_CPPR);
|
|
|
|
return rc;
|
|
}
|
|
|
|
X_STATIC int GLUE(X_PFX,h_ipi)(struct kvm_vcpu *vcpu, unsigned long server,
|
|
unsigned long mfrr)
|
|
{
|
|
struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
|
|
|
|
pr_devel("H_IPI(server=%08lx,mfrr=%ld)\n", server, mfrr);
|
|
|
|
xc->GLUE(X_STAT_PFX,h_ipi)++;
|
|
|
|
/* Find target */
|
|
vcpu = kvmppc_xive_find_server(vcpu->kvm, server);
|
|
if (!vcpu)
|
|
return H_PARAMETER;
|
|
xc = vcpu->arch.xive_vcpu;
|
|
|
|
/* Locklessly write over MFRR */
|
|
xc->mfrr = mfrr;
|
|
|
|
/*
|
|
* The load of xc->cppr below and the subsequent MMIO store
|
|
* to the IPI must happen after the above mfrr update is
|
|
* globally visible so that:
|
|
*
|
|
* - Synchronize with another CPU doing an H_EOI or a H_CPPR
|
|
* updating xc->cppr then reading xc->mfrr.
|
|
*
|
|
* - The target of the IPI sees the xc->mfrr update
|
|
*/
|
|
mb();
|
|
|
|
/* Shoot the IPI if most favored than target cppr */
|
|
if (mfrr < xc->cppr)
|
|
__x_writeq(0, __x_trig_page(&xc->vp_ipi_data));
|
|
|
|
return H_SUCCESS;
|
|
}
|