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/*
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* QEMU 8259 interrupt controller emulation
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*
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* Copyright (c) 2003-2004 Fabrice Bellard
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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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*/
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#include "hw.h" |
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#include "pc.h" |
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#include "isa.h" |
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#include "monitor.h" |
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#include "qemu-timer.h" |
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/* debug PIC */
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//#define DEBUG_PIC
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//#define DEBUG_IRQ_LATENCY
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//#define DEBUG_IRQ_COUNT
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typedef struct PicState { |
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uint8_t last_irr; /* edge detection */
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uint8_t irr; /* interrupt request register */
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uint8_t imr; /* interrupt mask register */
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uint8_t isr; /* interrupt service register */
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uint8_t priority_add; /* highest irq priority */
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uint8_t irq_base; |
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uint8_t read_reg_select; |
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uint8_t poll; |
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uint8_t special_mask; |
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uint8_t init_state; |
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uint8_t auto_eoi; |
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uint8_t rotate_on_auto_eoi; |
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uint8_t special_fully_nested_mode; |
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uint8_t init4; /* true if 4 byte init */
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uint8_t single_mode; /* true if slave pic is not initialized */
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uint8_t elcr; /* PIIX edge/trigger selection*/
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uint8_t elcr_mask; |
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PicState2 *pics_state; |
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} PicState; |
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struct PicState2 {
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/* 0 is master pic, 1 is slave pic */
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/* XXX: better separation between the two pics */
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PicState pics[2];
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qemu_irq parent_irq; |
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void *irq_request_opaque;
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}; |
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#if defined(DEBUG_PIC) || defined (DEBUG_IRQ_COUNT)
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static int irq_level[16]; |
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#endif
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#ifdef DEBUG_IRQ_COUNT
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static uint64_t irq_count[16]; |
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#endif
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/* set irq level. If an edge is detected, then the IRR is set to 1 */
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static inline void pic_set_irq1(PicState *s, int irq, int level) |
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{ |
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int mask;
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mask = 1 << irq;
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if (s->elcr & mask) {
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/* level triggered */
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if (level) {
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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 {
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/* edge triggered */
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if (level) {
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if ((s->last_irr & mask) == 0) |
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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->last_irr &= ~mask; |
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} |
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} |
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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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static inline int get_priority(PicState *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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static int pic_get_irq(PicState *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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/* 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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mask = s->isr; |
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if (s->special_mask)
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mask &= ~s->imr; |
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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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/* higher priority found: an irq should be generated */
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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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/* XXX: should not export it, but it is needed for an APIC kludge */
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void pic_update_irq(PicState2 *s)
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{ |
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int irq2, irq;
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/* first look at slave pic */
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irq2 = pic_get_irq(&s->pics[1]);
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if (irq2 >= 0) { |
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/* if irq request by slave pic, signal master PIC */
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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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/* look at requested irq */
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irq = pic_get_irq(&s->pics[0]);
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if (irq >= 0) { |
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#if defined(DEBUG_PIC)
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{ |
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int i;
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for(i = 0; i < 2; i++) { |
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printf("pic%d: imr=%x irr=%x padd=%d\n",
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i, s->pics[i].imr, s->pics[i].irr, |
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s->pics[i].priority_add); |
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} |
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} |
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printf("pic: cpu_interrupt\n");
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#endif
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qemu_irq_raise(s->parent_irq); |
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} |
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/* all targets should do this rather than acking the IRQ in the cpu */
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#if defined(TARGET_MIPS) || defined(TARGET_PPC) || defined(TARGET_ALPHA)
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else {
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qemu_irq_lower(s->parent_irq); |
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} |
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#endif
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} |
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#ifdef DEBUG_IRQ_LATENCY
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int64_t irq_time[16];
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#endif
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static void i8259_set_irq(void *opaque, int irq, int level) |
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{ |
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PicState2 *s = opaque; |
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#if defined(DEBUG_PIC) || defined(DEBUG_IRQ_COUNT)
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if (level != irq_level[irq]) {
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#if defined(DEBUG_PIC)
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printf("i8259_set_irq: irq=%d level=%d\n", irq, level);
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#endif
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irq_level[irq] = level; |
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#ifdef DEBUG_IRQ_COUNT
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if (level == 1) |
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irq_count[irq]++; |
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#endif
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} |
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#endif
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#ifdef DEBUG_IRQ_LATENCY
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if (level) {
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irq_time[irq] = qemu_get_clock(vm_clock); |
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} |
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#endif
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pic_set_irq1(&s->pics[irq >> 3], irq & 7, level); |
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pic_update_irq(s); |
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} |
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/* acknowledge interrupt 'irq' */
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static inline void pic_intack(PicState *s, int irq) |
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{ |
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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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} else {
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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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if (!(s->elcr & (1 << irq))) |
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s->irr &= ~(1 << irq);
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} |
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int pic_read_irq(PicState2 *s)
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{ |
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int irq, irq2, intno;
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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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/* spurious IRQ on slave controller */
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irq2 = 7;
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} |
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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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} |
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} else {
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/* spurious IRQ on host controller */
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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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#ifdef DEBUG_IRQ_LATENCY
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printf("IRQ%d latency=%0.3fus\n",
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irq, |
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(double)(qemu_get_clock(vm_clock) -
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irq_time[irq]) * 1000000.0 / get_ticks_per_sec()); |
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#endif
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#if defined(DEBUG_PIC)
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printf("pic_interrupt: irq=%d\n", irq);
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#endif
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return intno;
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} |
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static void pic_reset(void *opaque) |
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{ |
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PicState *s = opaque; |
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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->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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s->single_mode = 0;
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/* Note: ELCR is not reset */
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} |
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static void pic_ioport_write(void *opaque, uint32_t addr, uint32_t val) |
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{ |
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PicState *s = opaque; |
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int priority, cmd, irq;
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#ifdef DEBUG_PIC
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printf("pic_write: addr=0x%02x val=0x%02x\n", addr, val);
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#endif
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addr &= 1;
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if (addr == 0) { |
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if (val & 0x10) { |
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/* init */
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pic_reset(s); |
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/* deassert a pending interrupt */
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qemu_irq_lower(s->pics_state->parent_irq); |
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s->init_state = 1;
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s->init4 = val & 1;
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s->single_mode = val & 2;
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if (val & 0x08) |
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hw_error("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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s->isr &= ~(1 << irq);
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if (cmd == 5) |
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s->priority_add = (irq + 1) & 7; |
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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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s->isr &= ~(1 << 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->isr &= ~(1 << irq);
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s->priority_add = (irq + 1) & 7; |
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pic_update_irq(s->pics_state); |
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break;
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default:
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/* no operation */
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break;
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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: |
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/* normal mode */
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s->imr = val; |
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pic_update_irq(s->pics_state); |
352 |
break;
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case 1: |
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s->irq_base = val & 0xf8;
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s->init_state = s->single_mode ? (s->init4 ? 3 : 0) : 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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} |
363 |
break;
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case 3: |
365 |
s->special_fully_nested_mode = (val >> 4) & 1; |
366 |
s->auto_eoi = (val >> 1) & 1; |
367 |
s->init_state = 0;
|
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break;
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} |
370 |
} |
371 |
} |
372 |
|
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static uint32_t pic_poll_read (PicState *s, uint32_t addr1)
|
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{ |
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int ret;
|
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|
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ret = pic_get_irq(s); |
378 |
if (ret >= 0) { |
379 |
if (addr1 >> 7) { |
380 |
s->pics_state->pics[0].isr &= ~(1 << 2); |
381 |
s->pics_state->pics[0].irr &= ~(1 << 2); |
382 |
} |
383 |
s->irr &= ~(1 << ret);
|
384 |
s->isr &= ~(1 << ret);
|
385 |
if (addr1 >> 7 || ret != 2) |
386 |
pic_update_irq(s->pics_state); |
387 |
} else {
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388 |
ret = 0x07;
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pic_update_irq(s->pics_state); |
390 |
} |
391 |
|
392 |
return ret;
|
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} |
394 |
|
395 |
static uint32_t pic_ioport_read(void *opaque, uint32_t addr1) |
396 |
{ |
397 |
PicState *s = opaque; |
398 |
unsigned int addr; |
399 |
int ret;
|
400 |
|
401 |
addr = addr1; |
402 |
addr &= 1;
|
403 |
if (s->poll) {
|
404 |
ret = pic_poll_read(s, addr1); |
405 |
s->poll = 0;
|
406 |
} else {
|
407 |
if (addr == 0) { |
408 |
if (s->read_reg_select)
|
409 |
ret = s->isr; |
410 |
else
|
411 |
ret = s->irr; |
412 |
} else {
|
413 |
ret = s->imr; |
414 |
} |
415 |
} |
416 |
#ifdef DEBUG_PIC
|
417 |
printf("pic_read: addr=0x%02x val=0x%02x\n", addr1, ret);
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418 |
#endif
|
419 |
return ret;
|
420 |
} |
421 |
|
422 |
/* memory mapped interrupt status */
|
423 |
/* XXX: may be the same than pic_read_irq() */
|
424 |
uint32_t pic_intack_read(PicState2 *s) |
425 |
{ |
426 |
int ret;
|
427 |
|
428 |
ret = pic_poll_read(&s->pics[0], 0x00); |
429 |
if (ret == 2) |
430 |
ret = pic_poll_read(&s->pics[1], 0x80) + 8; |
431 |
/* Prepare for ISR read */
|
432 |
s->pics[0].read_reg_select = 1; |
433 |
|
434 |
return ret;
|
435 |
} |
436 |
|
437 |
static void elcr_ioport_write(void *opaque, uint32_t addr, uint32_t val) |
438 |
{ |
439 |
PicState *s = opaque; |
440 |
s->elcr = val & s->elcr_mask; |
441 |
} |
442 |
|
443 |
static uint32_t elcr_ioport_read(void *opaque, uint32_t addr1) |
444 |
{ |
445 |
PicState *s = opaque; |
446 |
return s->elcr;
|
447 |
} |
448 |
|
449 |
static const VMStateDescription vmstate_pic = { |
450 |
.name = "i8259",
|
451 |
.version_id = 1,
|
452 |
.minimum_version_id = 1,
|
453 |
.minimum_version_id_old = 1,
|
454 |
.fields = (VMStateField []) { |
455 |
VMSTATE_UINT8(last_irr, PicState), |
456 |
VMSTATE_UINT8(irr, PicState), |
457 |
VMSTATE_UINT8(imr, PicState), |
458 |
VMSTATE_UINT8(isr, PicState), |
459 |
VMSTATE_UINT8(priority_add, PicState), |
460 |
VMSTATE_UINT8(irq_base, PicState), |
461 |
VMSTATE_UINT8(read_reg_select, PicState), |
462 |
VMSTATE_UINT8(poll, PicState), |
463 |
VMSTATE_UINT8(special_mask, PicState), |
464 |
VMSTATE_UINT8(init_state, PicState), |
465 |
VMSTATE_UINT8(auto_eoi, PicState), |
466 |
VMSTATE_UINT8(rotate_on_auto_eoi, PicState), |
467 |
VMSTATE_UINT8(special_fully_nested_mode, PicState), |
468 |
VMSTATE_UINT8(init4, PicState), |
469 |
VMSTATE_UINT8(single_mode, PicState), |
470 |
VMSTATE_UINT8(elcr, PicState), |
471 |
VMSTATE_END_OF_LIST() |
472 |
} |
473 |
}; |
474 |
|
475 |
/* XXX: add generic master/slave system */
|
476 |
static void pic_init1(int io_addr, int elcr_addr, PicState *s) |
477 |
{ |
478 |
register_ioport_write(io_addr, 2, 1, pic_ioport_write, s); |
479 |
register_ioport_read(io_addr, 2, 1, pic_ioport_read, s); |
480 |
if (elcr_addr >= 0) { |
481 |
register_ioport_write(elcr_addr, 1, 1, elcr_ioport_write, s); |
482 |
register_ioport_read(elcr_addr, 1, 1, elcr_ioport_read, s); |
483 |
} |
484 |
vmstate_register(io_addr, &vmstate_pic, s); |
485 |
qemu_register_reset(pic_reset, s); |
486 |
} |
487 |
|
488 |
void pic_info(Monitor *mon)
|
489 |
{ |
490 |
int i;
|
491 |
PicState *s; |
492 |
|
493 |
if (!isa_pic)
|
494 |
return;
|
495 |
|
496 |
for(i=0;i<2;i++) { |
497 |
s = &isa_pic->pics[i]; |
498 |
monitor_printf(mon, "pic%d: irr=%02x imr=%02x isr=%02x hprio=%d "
|
499 |
"irq_base=%02x rr_sel=%d elcr=%02x fnm=%d\n",
|
500 |
i, s->irr, s->imr, s->isr, s->priority_add, |
501 |
s->irq_base, s->read_reg_select, s->elcr, |
502 |
s->special_fully_nested_mode); |
503 |
} |
504 |
} |
505 |
|
506 |
void irq_info(Monitor *mon)
|
507 |
{ |
508 |
#ifndef DEBUG_IRQ_COUNT
|
509 |
monitor_printf(mon, "irq statistic code not compiled.\n");
|
510 |
#else
|
511 |
int i;
|
512 |
int64_t count; |
513 |
|
514 |
monitor_printf(mon, "IRQ statistics:\n");
|
515 |
for (i = 0; i < 16; i++) { |
516 |
count = irq_count[i]; |
517 |
if (count > 0) |
518 |
monitor_printf(mon, "%2d: %" PRId64 "\n", i, count); |
519 |
} |
520 |
#endif
|
521 |
} |
522 |
|
523 |
qemu_irq *i8259_init(qemu_irq parent_irq) |
524 |
{ |
525 |
PicState2 *s; |
526 |
|
527 |
s = qemu_mallocz(sizeof(PicState2));
|
528 |
pic_init1(0x20, 0x4d0, &s->pics[0]); |
529 |
pic_init1(0xa0, 0x4d1, &s->pics[1]); |
530 |
s->pics[0].elcr_mask = 0xf8; |
531 |
s->pics[1].elcr_mask = 0xde; |
532 |
s->parent_irq = parent_irq; |
533 |
s->pics[0].pics_state = s;
|
534 |
s->pics[1].pics_state = s;
|
535 |
isa_pic = s; |
536 |
return qemu_allocate_irqs(i8259_set_irq, s, 16); |
537 |
} |