9195c4da26
If pit delivers interrupt while pic is masking it OS will never do EOI and ack notifier will not be called so when pit will be unmasked no pit interrupts will be delivered any more. Calling mask notifiers solves this issue. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
595 lines
13 KiB
C
595 lines
13 KiB
C
/*
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* 8259 interrupt controller emulation
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*
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* Copyright (c) 2003-2004 Fabrice Bellard
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* Copyright (c) 2007 Intel Corporation
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* Copyright 2009 Red Hat, Inc. and/or its affilates.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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* Authors:
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* Yaozu (Eddie) Dong <Eddie.dong@intel.com>
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* Port from Qemu.
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*/
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#include <linux/mm.h>
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#include <linux/slab.h>
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#include <linux/bitops.h>
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#include "irq.h"
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#include <linux/kvm_host.h>
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#include "trace.h"
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static void pic_irq_request(struct kvm *kvm, int level);
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static void pic_lock(struct kvm_pic *s)
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__acquires(&s->lock)
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{
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raw_spin_lock(&s->lock);
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}
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static void pic_unlock(struct kvm_pic *s)
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__releases(&s->lock)
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{
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bool wakeup = s->wakeup_needed;
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struct kvm_vcpu *vcpu, *found = NULL;
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int i;
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s->wakeup_needed = false;
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raw_spin_unlock(&s->lock);
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if (wakeup) {
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kvm_for_each_vcpu(i, vcpu, s->kvm) {
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if (kvm_apic_accept_pic_intr(vcpu)) {
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found = vcpu;
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break;
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}
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}
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if (!found)
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found = s->kvm->bsp_vcpu;
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kvm_vcpu_kick(found);
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}
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}
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static void pic_clear_isr(struct kvm_kpic_state *s, int irq)
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{
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s->isr &= ~(1 << irq);
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s->isr_ack |= (1 << irq);
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if (s != &s->pics_state->pics[0])
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irq += 8;
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/*
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* We are dropping lock while calling ack notifiers since ack
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* notifier callbacks for assigned devices call into PIC recursively.
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* Other interrupt may be delivered to PIC while lock is dropped but
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* it should be safe since PIC state is already updated at this stage.
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*/
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pic_unlock(s->pics_state);
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kvm_notify_acked_irq(s->pics_state->kvm, SELECT_PIC(irq), irq);
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pic_lock(s->pics_state);
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}
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void kvm_pic_clear_isr_ack(struct kvm *kvm)
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{
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struct kvm_pic *s = pic_irqchip(kvm);
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pic_lock(s);
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s->pics[0].isr_ack = 0xff;
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s->pics[1].isr_ack = 0xff;
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pic_unlock(s);
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}
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/*
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* set irq level. If an edge is detected, then the IRR is set to 1
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*/
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static inline int pic_set_irq1(struct kvm_kpic_state *s, int irq, int level)
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{
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int mask, ret = 1;
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mask = 1 << irq;
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if (s->elcr & mask) /* level triggered */
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if (level) {
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ret = !(s->irr & mask);
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s->irr |= mask;
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s->last_irr |= mask;
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} else {
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s->irr &= ~mask;
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s->last_irr &= ~mask;
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}
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else /* edge triggered */
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if (level) {
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if ((s->last_irr & mask) == 0) {
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ret = !(s->irr & mask);
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s->irr |= mask;
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}
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s->last_irr |= mask;
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} else
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s->last_irr &= ~mask;
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return (s->imr & mask) ? -1 : ret;
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}
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/*
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* return the highest priority found in mask (highest = smallest
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* number). Return 8 if no irq
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*/
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static inline int get_priority(struct kvm_kpic_state *s, int mask)
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{
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int priority;
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if (mask == 0)
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return 8;
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priority = 0;
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while ((mask & (1 << ((priority + s->priority_add) & 7))) == 0)
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priority++;
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return priority;
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}
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/*
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* return the pic wanted interrupt. return -1 if none
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*/
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static int pic_get_irq(struct kvm_kpic_state *s)
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{
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int mask, cur_priority, priority;
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mask = s->irr & ~s->imr;
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priority = get_priority(s, mask);
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if (priority == 8)
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return -1;
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/*
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* compute current priority. If special fully nested mode on the
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* master, the IRQ coming from the slave is not taken into account
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* for the priority computation.
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*/
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mask = s->isr;
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if (s->special_fully_nested_mode && s == &s->pics_state->pics[0])
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mask &= ~(1 << 2);
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cur_priority = get_priority(s, mask);
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if (priority < cur_priority)
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/*
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* higher priority found: an irq should be generated
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*/
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return (priority + s->priority_add) & 7;
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else
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return -1;
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}
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/*
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* raise irq to CPU if necessary. must be called every time the active
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* irq may change
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*/
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static void pic_update_irq(struct kvm_pic *s)
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{
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int irq2, irq;
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irq2 = pic_get_irq(&s->pics[1]);
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if (irq2 >= 0) {
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/*
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* if irq request by slave pic, signal master PIC
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*/
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pic_set_irq1(&s->pics[0], 2, 1);
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pic_set_irq1(&s->pics[0], 2, 0);
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}
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irq = pic_get_irq(&s->pics[0]);
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pic_irq_request(s->kvm, irq >= 0);
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}
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void kvm_pic_update_irq(struct kvm_pic *s)
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{
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pic_lock(s);
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pic_update_irq(s);
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pic_unlock(s);
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}
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int kvm_pic_set_irq(void *opaque, int irq, int level)
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{
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struct kvm_pic *s = opaque;
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int ret = -1;
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pic_lock(s);
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if (irq >= 0 && irq < PIC_NUM_PINS) {
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ret = pic_set_irq1(&s->pics[irq >> 3], irq & 7, level);
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pic_update_irq(s);
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trace_kvm_pic_set_irq(irq >> 3, irq & 7, s->pics[irq >> 3].elcr,
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s->pics[irq >> 3].imr, ret == 0);
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}
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pic_unlock(s);
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return ret;
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}
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/*
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* acknowledge interrupt 'irq'
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*/
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static inline void pic_intack(struct kvm_kpic_state *s, int irq)
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{
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s->isr |= 1 << irq;
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/*
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* We don't clear a level sensitive interrupt here
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*/
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if (!(s->elcr & (1 << irq)))
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s->irr &= ~(1 << irq);
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if (s->auto_eoi) {
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if (s->rotate_on_auto_eoi)
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s->priority_add = (irq + 1) & 7;
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pic_clear_isr(s, irq);
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}
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}
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int kvm_pic_read_irq(struct kvm *kvm)
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{
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int irq, irq2, intno;
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struct kvm_pic *s = pic_irqchip(kvm);
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pic_lock(s);
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irq = pic_get_irq(&s->pics[0]);
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if (irq >= 0) {
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pic_intack(&s->pics[0], irq);
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if (irq == 2) {
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irq2 = pic_get_irq(&s->pics[1]);
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if (irq2 >= 0)
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pic_intack(&s->pics[1], irq2);
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else
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/*
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* spurious IRQ on slave controller
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*/
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irq2 = 7;
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intno = s->pics[1].irq_base + irq2;
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irq = irq2 + 8;
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} else
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intno = s->pics[0].irq_base + irq;
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} else {
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/*
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* spurious IRQ on host controller
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*/
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irq = 7;
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intno = s->pics[0].irq_base + irq;
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}
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pic_update_irq(s);
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pic_unlock(s);
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return intno;
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}
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void kvm_pic_reset(struct kvm_kpic_state *s)
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{
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int irq;
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struct kvm_vcpu *vcpu0 = s->pics_state->kvm->bsp_vcpu;
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u8 irr = s->irr, isr = s->imr;
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s->last_irr = 0;
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s->irr = 0;
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s->imr = 0;
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s->isr = 0;
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s->isr_ack = 0xff;
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s->priority_add = 0;
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s->irq_base = 0;
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s->read_reg_select = 0;
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s->poll = 0;
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s->special_mask = 0;
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s->init_state = 0;
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s->auto_eoi = 0;
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s->rotate_on_auto_eoi = 0;
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s->special_fully_nested_mode = 0;
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s->init4 = 0;
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for (irq = 0; irq < PIC_NUM_PINS/2; irq++) {
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if (vcpu0 && kvm_apic_accept_pic_intr(vcpu0))
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if (irr & (1 << irq) || isr & (1 << irq)) {
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pic_clear_isr(s, irq);
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}
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}
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}
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static void pic_ioport_write(void *opaque, u32 addr, u32 val)
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{
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struct kvm_kpic_state *s = opaque;
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int priority, cmd, irq;
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addr &= 1;
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if (addr == 0) {
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if (val & 0x10) {
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kvm_pic_reset(s); /* init */
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/*
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* deassert a pending interrupt
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*/
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pic_irq_request(s->pics_state->kvm, 0);
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s->init_state = 1;
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s->init4 = val & 1;
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if (val & 0x02)
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printk(KERN_ERR "single mode not supported");
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if (val & 0x08)
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printk(KERN_ERR
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"level sensitive irq not supported");
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} else if (val & 0x08) {
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if (val & 0x04)
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s->poll = 1;
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if (val & 0x02)
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s->read_reg_select = val & 1;
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if (val & 0x40)
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s->special_mask = (val >> 5) & 1;
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} else {
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cmd = val >> 5;
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switch (cmd) {
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case 0:
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case 4:
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s->rotate_on_auto_eoi = cmd >> 2;
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break;
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case 1: /* end of interrupt */
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case 5:
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priority = get_priority(s, s->isr);
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if (priority != 8) {
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irq = (priority + s->priority_add) & 7;
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if (cmd == 5)
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s->priority_add = (irq + 1) & 7;
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pic_clear_isr(s, irq);
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pic_update_irq(s->pics_state);
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}
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break;
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case 3:
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irq = val & 7;
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pic_clear_isr(s, irq);
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pic_update_irq(s->pics_state);
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break;
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case 6:
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s->priority_add = (val + 1) & 7;
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pic_update_irq(s->pics_state);
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break;
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case 7:
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irq = val & 7;
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s->priority_add = (irq + 1) & 7;
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pic_clear_isr(s, irq);
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pic_update_irq(s->pics_state);
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break;
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default:
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break; /* no operation */
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}
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}
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} else
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switch (s->init_state) {
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case 0: { /* normal mode */
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u8 imr_diff = s->imr ^ val,
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off = (s == &s->pics_state->pics[0]) ? 0 : 8;
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s->imr = val;
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for (irq = 0; irq < PIC_NUM_PINS/2; irq++)
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if (imr_diff & (1 << irq))
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kvm_fire_mask_notifiers(
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s->pics_state->kvm,
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SELECT_PIC(irq + off),
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irq + off,
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!!(s->imr & (1 << irq)));
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pic_update_irq(s->pics_state);
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break;
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}
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case 1:
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s->irq_base = val & 0xf8;
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s->init_state = 2;
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break;
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case 2:
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if (s->init4)
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s->init_state = 3;
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else
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s->init_state = 0;
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break;
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case 3:
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s->special_fully_nested_mode = (val >> 4) & 1;
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s->auto_eoi = (val >> 1) & 1;
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s->init_state = 0;
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break;
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}
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}
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static u32 pic_poll_read(struct kvm_kpic_state *s, u32 addr1)
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{
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int ret;
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ret = pic_get_irq(s);
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if (ret >= 0) {
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if (addr1 >> 7) {
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s->pics_state->pics[0].isr &= ~(1 << 2);
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s->pics_state->pics[0].irr &= ~(1 << 2);
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}
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s->irr &= ~(1 << ret);
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pic_clear_isr(s, ret);
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if (addr1 >> 7 || ret != 2)
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pic_update_irq(s->pics_state);
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} else {
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ret = 0x07;
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pic_update_irq(s->pics_state);
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}
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return ret;
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}
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static u32 pic_ioport_read(void *opaque, u32 addr1)
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{
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struct kvm_kpic_state *s = opaque;
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unsigned int addr;
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int ret;
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addr = addr1;
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addr &= 1;
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if (s->poll) {
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ret = pic_poll_read(s, addr1);
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s->poll = 0;
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} else
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if (addr == 0)
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if (s->read_reg_select)
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ret = s->isr;
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else
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ret = s->irr;
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else
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ret = s->imr;
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return ret;
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}
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static void elcr_ioport_write(void *opaque, u32 addr, u32 val)
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{
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struct kvm_kpic_state *s = opaque;
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s->elcr = val & s->elcr_mask;
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}
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static u32 elcr_ioport_read(void *opaque, u32 addr1)
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{
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struct kvm_kpic_state *s = opaque;
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return s->elcr;
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}
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static int picdev_in_range(gpa_t addr)
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{
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switch (addr) {
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case 0x20:
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case 0x21:
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case 0xa0:
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case 0xa1:
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case 0x4d0:
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case 0x4d1:
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return 1;
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default:
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return 0;
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}
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}
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static inline struct kvm_pic *to_pic(struct kvm_io_device *dev)
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{
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return container_of(dev, struct kvm_pic, dev);
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}
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static int picdev_write(struct kvm_io_device *this,
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gpa_t addr, int len, const void *val)
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{
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struct kvm_pic *s = to_pic(this);
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unsigned char data = *(unsigned char *)val;
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if (!picdev_in_range(addr))
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return -EOPNOTSUPP;
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if (len != 1) {
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if (printk_ratelimit())
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printk(KERN_ERR "PIC: non byte write\n");
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return 0;
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}
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pic_lock(s);
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switch (addr) {
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case 0x20:
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case 0x21:
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case 0xa0:
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case 0xa1:
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pic_ioport_write(&s->pics[addr >> 7], addr, data);
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break;
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case 0x4d0:
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case 0x4d1:
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elcr_ioport_write(&s->pics[addr & 1], addr, data);
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break;
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}
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pic_unlock(s);
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return 0;
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}
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static int picdev_read(struct kvm_io_device *this,
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gpa_t addr, int len, void *val)
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{
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struct kvm_pic *s = to_pic(this);
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unsigned char data = 0;
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if (!picdev_in_range(addr))
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return -EOPNOTSUPP;
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if (len != 1) {
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if (printk_ratelimit())
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printk(KERN_ERR "PIC: non byte read\n");
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return 0;
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}
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pic_lock(s);
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switch (addr) {
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case 0x20:
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case 0x21:
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case 0xa0:
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case 0xa1:
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data = pic_ioport_read(&s->pics[addr >> 7], addr);
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break;
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case 0x4d0:
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case 0x4d1:
|
|
data = elcr_ioport_read(&s->pics[addr & 1], addr);
|
|
break;
|
|
}
|
|
*(unsigned char *)val = data;
|
|
pic_unlock(s);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* callback when PIC0 irq status changed
|
|
*/
|
|
static void pic_irq_request(struct kvm *kvm, int level)
|
|
{
|
|
struct kvm_vcpu *vcpu = kvm->bsp_vcpu;
|
|
struct kvm_pic *s = pic_irqchip(kvm);
|
|
int irq = pic_get_irq(&s->pics[0]);
|
|
|
|
s->output = level;
|
|
if (vcpu && level && (s->pics[0].isr_ack & (1 << irq))) {
|
|
s->pics[0].isr_ack &= ~(1 << irq);
|
|
s->wakeup_needed = true;
|
|
}
|
|
}
|
|
|
|
static const struct kvm_io_device_ops picdev_ops = {
|
|
.read = picdev_read,
|
|
.write = picdev_write,
|
|
};
|
|
|
|
struct kvm_pic *kvm_create_pic(struct kvm *kvm)
|
|
{
|
|
struct kvm_pic *s;
|
|
int ret;
|
|
|
|
s = kzalloc(sizeof(struct kvm_pic), GFP_KERNEL);
|
|
if (!s)
|
|
return NULL;
|
|
raw_spin_lock_init(&s->lock);
|
|
s->kvm = kvm;
|
|
s->pics[0].elcr_mask = 0xf8;
|
|
s->pics[1].elcr_mask = 0xde;
|
|
s->pics[0].pics_state = s;
|
|
s->pics[1].pics_state = s;
|
|
|
|
/*
|
|
* Initialize PIO device
|
|
*/
|
|
kvm_iodevice_init(&s->dev, &picdev_ops);
|
|
mutex_lock(&kvm->slots_lock);
|
|
ret = kvm_io_bus_register_dev(kvm, KVM_PIO_BUS, &s->dev);
|
|
mutex_unlock(&kvm->slots_lock);
|
|
if (ret < 0) {
|
|
kfree(s);
|
|
return NULL;
|
|
}
|
|
|
|
return s;
|
|
}
|
|
|
|
void kvm_destroy_pic(struct kvm *kvm)
|
|
{
|
|
struct kvm_pic *vpic = kvm->arch.vpic;
|
|
|
|
if (vpic) {
|
|
kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, &vpic->dev);
|
|
kvm->arch.vpic = NULL;
|
|
kfree(vpic);
|
|
}
|
|
}
|