qemu/hw/i8259.c
Jan Kiszka 8217606e6e Introduce reset notifier order
Add the parameter 'order' to qemu_register_reset and sort callbacks on
registration. On system reset, callbacks with lower order will be
invoked before those with higher order. Update all existing users to the
standard order 0.

Note: At least for x86, the existing users seem to assume that handlers
are called in their registration order. Therefore, the patch preserves
this property. If someone feels bored, (s)he could try to identify this
dependency and express it properly on callback registration.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-05-22 10:50:34 -05:00

571 lines
15 KiB
C

/*
* QEMU 8259 interrupt controller emulation
*
* Copyright (c) 2003-2004 Fabrice Bellard
*
* 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.
*/
#include "hw.h"
#include "pc.h"
#include "isa.h"
#include "monitor.h"
/* debug PIC */
//#define DEBUG_PIC
//#define DEBUG_IRQ_LATENCY
//#define DEBUG_IRQ_COUNT
typedef struct PicState {
uint8_t last_irr; /* edge detection */
uint8_t irr; /* interrupt request register */
uint8_t imr; /* interrupt mask register */
uint8_t isr; /* interrupt service register */
uint8_t priority_add; /* highest irq priority */
uint8_t irq_base;
uint8_t read_reg_select;
uint8_t poll;
uint8_t special_mask;
uint8_t init_state;
uint8_t auto_eoi;
uint8_t rotate_on_auto_eoi;
uint8_t special_fully_nested_mode;
uint8_t init4; /* true if 4 byte init */
uint8_t single_mode; /* true if slave pic is not initialized */
uint8_t elcr; /* PIIX edge/trigger selection*/
uint8_t elcr_mask;
PicState2 *pics_state;
} PicState;
struct PicState2 {
/* 0 is master pic, 1 is slave pic */
/* XXX: better separation between the two pics */
PicState pics[2];
qemu_irq parent_irq;
void *irq_request_opaque;
/* IOAPIC callback support */
SetIRQFunc *alt_irq_func;
void *alt_irq_opaque;
};
#if defined(DEBUG_PIC) || defined (DEBUG_IRQ_COUNT)
static int irq_level[16];
#endif
#ifdef DEBUG_IRQ_COUNT
static uint64_t irq_count[16];
#endif
/* set irq level. If an edge is detected, then the IRR is set to 1 */
static inline void pic_set_irq1(PicState *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(PicState *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(PicState *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_mask)
mask &= ~s->imr;
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 */
/* XXX: should not export it, but it is needed for an APIC kludge */
void pic_update_irq(PicState2 *s)
{
int irq2, irq;
/* first look at slave pic */
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);
}
/* look at requested irq */
irq = pic_get_irq(&s->pics[0]);
if (irq >= 0) {
#if defined(DEBUG_PIC)
{
int i;
for(i = 0; i < 2; i++) {
printf("pic%d: imr=%x irr=%x padd=%d\n",
i, s->pics[i].imr, s->pics[i].irr,
s->pics[i].priority_add);
}
}
printf("pic: cpu_interrupt\n");
#endif
qemu_irq_raise(s->parent_irq);
}
/* all targets should do this rather than acking the IRQ in the cpu */
#if defined(TARGET_MIPS) || defined(TARGET_PPC) || defined(TARGET_ALPHA)
else {
qemu_irq_lower(s->parent_irq);
}
#endif
}
#ifdef DEBUG_IRQ_LATENCY
int64_t irq_time[16];
#endif
static void i8259_set_irq(void *opaque, int irq, int level)
{
PicState2 *s = opaque;
#if defined(DEBUG_PIC) || defined(DEBUG_IRQ_COUNT)
if (level != irq_level[irq]) {
#if defined(DEBUG_PIC)
printf("i8259_set_irq: irq=%d level=%d\n", irq, level);
#endif
irq_level[irq] = level;
#ifdef DEBUG_IRQ_COUNT
if (level == 1)
irq_count[irq]++;
#endif
}
#endif
#ifdef DEBUG_IRQ_LATENCY
if (level) {
irq_time[irq] = qemu_get_clock(vm_clock);
}
#endif
pic_set_irq1(&s->pics[irq >> 3], irq & 7, level);
/* used for IOAPIC irqs */
if (s->alt_irq_func)
s->alt_irq_func(s->alt_irq_opaque, irq, level);
pic_update_irq(s);
}
/* acknowledge interrupt 'irq' */
static inline void pic_intack(PicState *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 pic_read_irq(PicState2 *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);
#ifdef DEBUG_IRQ_LATENCY
printf("IRQ%d latency=%0.3fus\n",
irq,
(double)(qemu_get_clock(vm_clock) - irq_time[irq]) * 1000000.0 / ticks_per_sec);
#endif
#if defined(DEBUG_PIC)
printf("pic_interrupt: irq=%d\n", irq);
#endif
return intno;
}
static void pic_reset(void *opaque)
{
PicState *s = opaque;
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;
s->single_mode = 0;
/* Note: ELCR is not reset */
}
static void pic_ioport_write(void *opaque, uint32_t addr, uint32_t val)
{
PicState *s = opaque;
int priority, cmd, irq;
#ifdef DEBUG_PIC
printf("pic_write: addr=0x%02x val=0x%02x\n", addr, val);
#endif
addr &= 1;
if (addr == 0) {
if (val & 0x10) {
/* init */
pic_reset(s);
/* deassert a pending interrupt */
qemu_irq_lower(s->pics_state->parent_irq);
s->init_state = 1;
s->init4 = val & 1;
s->single_mode = val & 2;
if (val & 0x08)
hw_error("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:
/* no operation */
break;
}
}
} 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 = s->single_mode ? (s->init4 ? 3 : 0) : 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 uint32_t pic_poll_read (PicState *s, uint32_t 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 uint32_t pic_ioport_read(void *opaque, uint32_t addr1)
{
PicState *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;
}
}
#ifdef DEBUG_PIC
printf("pic_read: addr=0x%02x val=0x%02x\n", addr1, ret);
#endif
return ret;
}
/* memory mapped interrupt status */
/* XXX: may be the same than pic_read_irq() */
uint32_t pic_intack_read(PicState2 *s)
{
int ret;
ret = pic_poll_read(&s->pics[0], 0x00);
if (ret == 2)
ret = pic_poll_read(&s->pics[1], 0x80) + 8;
/* Prepare for ISR read */
s->pics[0].read_reg_select = 1;
return ret;
}
static void elcr_ioport_write(void *opaque, uint32_t addr, uint32_t val)
{
PicState *s = opaque;
s->elcr = val & s->elcr_mask;
}
static uint32_t elcr_ioport_read(void *opaque, uint32_t addr1)
{
PicState *s = opaque;
return s->elcr;
}
static void pic_save(QEMUFile *f, void *opaque)
{
PicState *s = opaque;
qemu_put_8s(f, &s->last_irr);
qemu_put_8s(f, &s->irr);
qemu_put_8s(f, &s->imr);
qemu_put_8s(f, &s->isr);
qemu_put_8s(f, &s->priority_add);
qemu_put_8s(f, &s->irq_base);
qemu_put_8s(f, &s->read_reg_select);
qemu_put_8s(f, &s->poll);
qemu_put_8s(f, &s->special_mask);
qemu_put_8s(f, &s->init_state);
qemu_put_8s(f, &s->auto_eoi);
qemu_put_8s(f, &s->rotate_on_auto_eoi);
qemu_put_8s(f, &s->special_fully_nested_mode);
qemu_put_8s(f, &s->init4);
qemu_put_8s(f, &s->single_mode);
qemu_put_8s(f, &s->elcr);
}
static int pic_load(QEMUFile *f, void *opaque, int version_id)
{
PicState *s = opaque;
if (version_id != 1)
return -EINVAL;
qemu_get_8s(f, &s->last_irr);
qemu_get_8s(f, &s->irr);
qemu_get_8s(f, &s->imr);
qemu_get_8s(f, &s->isr);
qemu_get_8s(f, &s->priority_add);
qemu_get_8s(f, &s->irq_base);
qemu_get_8s(f, &s->read_reg_select);
qemu_get_8s(f, &s->poll);
qemu_get_8s(f, &s->special_mask);
qemu_get_8s(f, &s->init_state);
qemu_get_8s(f, &s->auto_eoi);
qemu_get_8s(f, &s->rotate_on_auto_eoi);
qemu_get_8s(f, &s->special_fully_nested_mode);
qemu_get_8s(f, &s->init4);
qemu_get_8s(f, &s->single_mode);
qemu_get_8s(f, &s->elcr);
return 0;
}
/* XXX: add generic master/slave system */
static void pic_init1(int io_addr, int elcr_addr, PicState *s)
{
register_ioport_write(io_addr, 2, 1, pic_ioport_write, s);
register_ioport_read(io_addr, 2, 1, pic_ioport_read, s);
if (elcr_addr >= 0) {
register_ioport_write(elcr_addr, 1, 1, elcr_ioport_write, s);
register_ioport_read(elcr_addr, 1, 1, elcr_ioport_read, s);
}
register_savevm("i8259", io_addr, 1, pic_save, pic_load, s);
qemu_register_reset(pic_reset, 0, s);
}
void pic_info(Monitor *mon)
{
int i;
PicState *s;
if (!isa_pic)
return;
for(i=0;i<2;i++) {
s = &isa_pic->pics[i];
monitor_printf(mon, "pic%d: irr=%02x imr=%02x isr=%02x hprio=%d "
"irq_base=%02x rr_sel=%d elcr=%02x fnm=%d\n",
i, s->irr, s->imr, s->isr, s->priority_add,
s->irq_base, s->read_reg_select, s->elcr,
s->special_fully_nested_mode);
}
}
void irq_info(Monitor *mon)
{
#ifndef DEBUG_IRQ_COUNT
monitor_printf(mon, "irq statistic code not compiled.\n");
#else
int i;
int64_t count;
monitor_printf(mon, "IRQ statistics:\n");
for (i = 0; i < 16; i++) {
count = irq_count[i];
if (count > 0)
monitor_printf(mon, "%2d: %" PRId64 "\n", i, count);
}
#endif
}
qemu_irq *i8259_init(qemu_irq parent_irq)
{
PicState2 *s;
s = qemu_mallocz(sizeof(PicState2));
pic_init1(0x20, 0x4d0, &s->pics[0]);
pic_init1(0xa0, 0x4d1, &s->pics[1]);
s->pics[0].elcr_mask = 0xf8;
s->pics[1].elcr_mask = 0xde;
s->parent_irq = parent_irq;
s->pics[0].pics_state = s;
s->pics[1].pics_state = s;
isa_pic = s;
return qemu_allocate_irqs(i8259_set_irq, s, 16);
}
void pic_set_alt_irq_func(PicState2 *s, SetIRQFunc *alt_irq_func,
void *alt_irq_opaque)
{
s->alt_irq_func = alt_irq_func;
s->alt_irq_opaque = alt_irq_opaque;
}