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