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-rw-r--r--arch/x86/kvm/i8259.c450
1 files changed, 450 insertions, 0 deletions
diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
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+++ b/arch/x86/kvm/i8259.c
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+/*
+ * 8259 interrupt controller emulation
+ *
+ * Copyright (c) 2003-2004 Fabrice Bellard
+ * Copyright (c) 2007 Intel Corporation
+ *
+ * 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 "irq.h"
+
+#include <linux/kvm_host.h>
+
+/*
+ * set irq level. If an edge is detected, then the IRR is set to 1
+ */
+static inline void pic_set_irq1(struct kvm_kpic_state *s, int irq, int level)
+{
+ int mask;
+ mask = 1 << irq;
+ if (s->elcr & mask) /* level triggered */
+ if (level) {
+ 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)
+ s->irr |= mask;
+ s->last_irr |= mask;
+ } else
+ s->last_irr &= ~mask;
+}
+
+/*
+ * 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]);
+ if (irq >= 0)
+ s->irq_request(s->irq_request_opaque, 1);
+ else
+ s->irq_request(s->irq_request_opaque, 0);
+}
+
+void kvm_pic_update_irq(struct kvm_pic *s)
+{
+ pic_update_irq(s);
+}
+
+void kvm_pic_set_irq(void *opaque, int irq, int level)
+{
+ struct kvm_pic *s = opaque;
+
+ pic_set_irq1(&s->pics[irq >> 3], irq & 7, level);
+ pic_update_irq(s);
+}
+
+/*
+ * acknowledge interrupt 'irq'
+ */
+static inline void pic_intack(struct kvm_kpic_state *s, int irq)
+{
+ if (s->auto_eoi) {
+ if (s->rotate_on_auto_eoi)
+ s->priority_add = (irq + 1) & 7;
+ } else
+ s->isr |= (1 << irq);
+ /*
+ * We don't clear a level sensitive interrupt here
+ */
+ if (!(s->elcr & (1 << irq)))
+ s->irr &= ~(1 << irq);
+}
+
+int kvm_pic_read_irq(struct kvm_pic *s)
+{
+ int irq, irq2, intno;
+
+ 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);
+
+ return intno;
+}
+
+void kvm_pic_reset(struct kvm_kpic_state *s)
+{
+ s->last_irr = 0;
+ s->irr = 0;
+ s->imr = 0;
+ s->isr = 0;
+ 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;
+}
+
+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) {
+ kvm_pic_reset(s); /* init */
+ /*
+ * deassert a pending interrupt
+ */
+ s->pics_state->irq_request(s->pics_state->
+ irq_request_opaque, 0);
+ s->init_state = 1;
+ s->init4 = val & 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;
+ s->isr &= ~(1 << irq);
+ if (cmd == 5)
+ s->priority_add = (irq + 1) & 7;
+ pic_update_irq(s->pics_state);
+ }
+ break;
+ case 3:
+ irq = val & 7;
+ s->isr &= ~(1 << 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->isr &= ~(1 << irq);
+ s->priority_add = (irq + 1) & 7;
+ pic_update_irq(s->pics_state);
+ break;
+ default:
+ break; /* no operation */
+ }
+ }
+ } else
+ switch (s->init_state) {
+ case 0: /* normal mode */
+ s->imr = val;
+ 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);
+ s->isr &= ~(1 << 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(struct kvm_io_device *this, gpa_t addr)
+{
+ switch (addr) {
+ case 0x20:
+ case 0x21:
+ case 0xa0:
+ case 0xa1:
+ case 0x4d0:
+ case 0x4d1:
+ return 1;
+ default:
+ return 0;
+ }
+}
+
+static void picdev_write(struct kvm_io_device *this,
+ gpa_t addr, int len, const void *val)
+{
+ struct kvm_pic *s = this->private;
+ unsigned char data = *(unsigned char *)val;
+
+ if (len != 1) {
+ if (printk_ratelimit())
+ printk(KERN_ERR "PIC: non byte write\n");
+ return;
+ }
+ 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;
+ }
+}
+
+static void picdev_read(struct kvm_io_device *this,
+ gpa_t addr, int len, void *val)
+{
+ struct kvm_pic *s = this->private;
+ unsigned char data = 0;
+
+ if (len != 1) {
+ if (printk_ratelimit())
+ printk(KERN_ERR "PIC: non byte read\n");
+ return;
+ }
+ 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;
+}
+
+/*
+ * callback when PIC0 irq status changed
+ */
+static void pic_irq_request(void *opaque, int level)
+{
+ struct kvm *kvm = opaque;
+ struct kvm_vcpu *vcpu = kvm->vcpus[0];
+
+ pic_irqchip(kvm)->output = level;
+ if (vcpu)
+ kvm_vcpu_kick(vcpu);
+}
+
+struct kvm_pic *kvm_create_pic(struct kvm *kvm)
+{
+ struct kvm_pic *s;
+ s = kzalloc(sizeof(struct kvm_pic), GFP_KERNEL);
+ if (!s)
+ return NULL;
+ s->pics[0].elcr_mask = 0xf8;
+ s->pics[1].elcr_mask = 0xde;
+ s->irq_request = pic_irq_request;
+ s->irq_request_opaque = kvm;
+ s->pics[0].pics_state = s;
+ s->pics[1].pics_state = s;
+
+ /*
+ * Initialize PIO device
+ */
+ s->dev.read = picdev_read;
+ s->dev.write = picdev_write;
+ s->dev.in_range = picdev_in_range;
+ s->dev.private = s;
+ kvm_io_bus_register_dev(&kvm->pio_bus, &s->dev);
+ return s;
+}