2 * 8259 interrupt controller emulation
4 * Copyright (c) 2003-2004 Fabrice Bellard
5 * Copyright (c) 2007 Intel Corporation
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
25 * Yaozu (Eddie) Dong <Eddie.dong@intel.com>
29 #include <linux/bitops.h>
32 #include <linux/kvm_host.h>
35 static void pic_lock(struct kvm_pic *s)
41 static void pic_unlock(struct kvm_pic *s)
44 spin_unlock(&s->lock);
47 static void pic_clear_isr(struct kvm_kpic_state *s, int irq)
49 s->isr &= ~(1 << irq);
50 s->isr_ack |= (1 << irq);
51 if (s != &s->pics_state->pics[0])
53 kvm_notify_acked_irq(s->pics_state->kvm, SELECT_PIC(irq), irq);
56 void kvm_pic_clear_isr_ack(struct kvm *kvm)
58 struct kvm_pic *s = pic_irqchip(kvm);
60 s->pics[0].isr_ack = 0xff;
61 s->pics[1].isr_ack = 0xff;
66 * set irq level. If an edge is detected, then the IRR is set to 1
68 static inline int pic_set_irq1(struct kvm_kpic_state *s, int irq, int level)
72 if (s->elcr & mask) /* level triggered */
74 ret = !(s->irr & mask);
81 else /* edge triggered */
83 if ((s->last_irr & mask) == 0) {
84 ret = !(s->irr & mask);
91 return (s->imr & mask) ? -1 : ret;
95 * return the highest priority found in mask (highest = smallest
96 * number). Return 8 if no irq
98 static inline int get_priority(struct kvm_kpic_state *s, int mask)
104 while ((mask & (1 << ((priority + s->priority_add) & 7))) == 0)
110 * return the pic wanted interrupt. return -1 if none
112 static int pic_get_irq(struct kvm_kpic_state *s)
114 int mask, cur_priority, priority;
116 mask = s->irr & ~s->imr;
117 priority = get_priority(s, mask);
121 * compute current priority. If special fully nested mode on the
122 * master, the IRQ coming from the slave is not taken into account
123 * for the priority computation.
126 if (s->special_fully_nested_mode && s == &s->pics_state->pics[0])
128 cur_priority = get_priority(s, mask);
129 if (priority < cur_priority)
131 * higher priority found: an irq should be generated
133 return (priority + s->priority_add) & 7;
139 * raise irq to CPU if necessary. must be called every time the active
142 static void pic_update_irq(struct kvm_pic *s)
146 irq2 = pic_get_irq(&s->pics[1]);
149 * if irq request by slave pic, signal master PIC
151 pic_set_irq1(&s->pics[0], 2, 1);
152 pic_set_irq1(&s->pics[0], 2, 0);
154 irq = pic_get_irq(&s->pics[0]);
156 s->irq_request(s->irq_request_opaque, 1);
158 s->irq_request(s->irq_request_opaque, 0);
161 void kvm_pic_update_irq(struct kvm_pic *s)
168 int kvm_pic_set_irq(void *opaque, int irq, int level)
170 struct kvm_pic *s = opaque;
174 if (irq >= 0 && irq < PIC_NUM_PINS) {
175 ret = pic_set_irq1(&s->pics[irq >> 3], irq & 7, level);
177 trace_kvm_pic_set_irq(irq >> 3, irq & 7, s->pics[irq >> 3].elcr,
178 s->pics[irq >> 3].imr, ret == 0);
186 * acknowledge interrupt 'irq'
188 static inline void pic_intack(struct kvm_kpic_state *s, int irq)
192 if (s->rotate_on_auto_eoi)
193 s->priority_add = (irq + 1) & 7;
194 pic_clear_isr(s, irq);
197 * We don't clear a level sensitive interrupt here
199 if (!(s->elcr & (1 << irq)))
200 s->irr &= ~(1 << irq);
203 int kvm_pic_read_irq(struct kvm *kvm)
205 int irq, irq2, intno;
206 struct kvm_pic *s = pic_irqchip(kvm);
209 irq = pic_get_irq(&s->pics[0]);
211 pic_intack(&s->pics[0], irq);
213 irq2 = pic_get_irq(&s->pics[1]);
215 pic_intack(&s->pics[1], irq2);
218 * spurious IRQ on slave controller
221 intno = s->pics[1].irq_base + irq2;
224 intno = s->pics[0].irq_base + irq;
227 * spurious IRQ on host controller
230 intno = s->pics[0].irq_base + irq;
238 void kvm_pic_reset(struct kvm_kpic_state *s)
241 struct kvm *kvm = s->pics_state->irq_request_opaque;
242 struct kvm_vcpu *vcpu0 = kvm->bsp_vcpu;
244 if (s == &s->pics_state->pics[0])
249 for (irq = 0; irq < PIC_NUM_PINS/2; irq++) {
250 if (vcpu0 && kvm_apic_accept_pic_intr(vcpu0))
251 if (s->irr & (1 << irq) || s->isr & (1 << irq)) {
253 kvm_notify_acked_irq(kvm, SELECT_PIC(n), n);
263 s->read_reg_select = 0;
268 s->rotate_on_auto_eoi = 0;
269 s->special_fully_nested_mode = 0;
273 static void pic_ioport_write(void *opaque, u32 addr, u32 val)
275 struct kvm_kpic_state *s = opaque;
276 int priority, cmd, irq;
281 kvm_pic_reset(s); /* init */
283 * deassert a pending interrupt
285 s->pics_state->irq_request(s->pics_state->
286 irq_request_opaque, 0);
290 printk(KERN_ERR "single mode not supported");
293 "level sensitive irq not supported");
294 } else if (val & 0x08) {
298 s->read_reg_select = val & 1;
300 s->special_mask = (val >> 5) & 1;
306 s->rotate_on_auto_eoi = cmd >> 2;
308 case 1: /* end of interrupt */
310 priority = get_priority(s, s->isr);
312 irq = (priority + s->priority_add) & 7;
313 pic_clear_isr(s, irq);
315 s->priority_add = (irq + 1) & 7;
316 pic_update_irq(s->pics_state);
321 pic_clear_isr(s, irq);
322 pic_update_irq(s->pics_state);
325 s->priority_add = (val + 1) & 7;
326 pic_update_irq(s->pics_state);
330 s->priority_add = (irq + 1) & 7;
331 pic_clear_isr(s, irq);
332 pic_update_irq(s->pics_state);
335 break; /* no operation */
339 switch (s->init_state) {
340 case 0: /* normal mode */
342 pic_update_irq(s->pics_state);
345 s->irq_base = val & 0xf8;
355 s->special_fully_nested_mode = (val >> 4) & 1;
356 s->auto_eoi = (val >> 1) & 1;
362 static u32 pic_poll_read(struct kvm_kpic_state *s, u32 addr1)
366 ret = pic_get_irq(s);
369 s->pics_state->pics[0].isr &= ~(1 << 2);
370 s->pics_state->pics[0].irr &= ~(1 << 2);
372 s->irr &= ~(1 << ret);
373 pic_clear_isr(s, ret);
374 if (addr1 >> 7 || ret != 2)
375 pic_update_irq(s->pics_state);
378 pic_update_irq(s->pics_state);
384 static u32 pic_ioport_read(void *opaque, u32 addr1)
386 struct kvm_kpic_state *s = opaque;
393 ret = pic_poll_read(s, addr1);
397 if (s->read_reg_select)
406 static void elcr_ioport_write(void *opaque, u32 addr, u32 val)
408 struct kvm_kpic_state *s = opaque;
409 s->elcr = val & s->elcr_mask;
412 static u32 elcr_ioport_read(void *opaque, u32 addr1)
414 struct kvm_kpic_state *s = opaque;
418 static int picdev_in_range(gpa_t addr)
433 static inline struct kvm_pic *to_pic(struct kvm_io_device *dev)
435 return container_of(dev, struct kvm_pic, dev);
438 static int picdev_write(struct kvm_io_device *this,
439 gpa_t addr, int len, const void *val)
441 struct kvm_pic *s = to_pic(this);
442 unsigned char data = *(unsigned char *)val;
443 if (!picdev_in_range(addr))
447 if (printk_ratelimit())
448 printk(KERN_ERR "PIC: non byte write\n");
457 pic_ioport_write(&s->pics[addr >> 7], addr, data);
461 elcr_ioport_write(&s->pics[addr & 1], addr, data);
468 static int picdev_read(struct kvm_io_device *this,
469 gpa_t addr, int len, void *val)
471 struct kvm_pic *s = to_pic(this);
472 unsigned char data = 0;
473 if (!picdev_in_range(addr))
477 if (printk_ratelimit())
478 printk(KERN_ERR "PIC: non byte read\n");
487 data = pic_ioport_read(&s->pics[addr >> 7], addr);
491 data = elcr_ioport_read(&s->pics[addr & 1], addr);
494 *(unsigned char *)val = data;
500 * callback when PIC0 irq status changed
502 static void pic_irq_request(void *opaque, int level)
504 struct kvm *kvm = opaque;
505 struct kvm_vcpu *vcpu = kvm->bsp_vcpu;
506 struct kvm_pic *s = pic_irqchip(kvm);
507 int irq = pic_get_irq(&s->pics[0]);
510 if (vcpu && level && (s->pics[0].isr_ack & (1 << irq))) {
511 s->pics[0].isr_ack &= ~(1 << irq);
516 static const struct kvm_io_device_ops picdev_ops = {
518 .write = picdev_write,
521 struct kvm_pic *kvm_create_pic(struct kvm *kvm)
526 s = kzalloc(sizeof(struct kvm_pic), GFP_KERNEL);
529 spin_lock_init(&s->lock);
531 s->pics[0].elcr_mask = 0xf8;
532 s->pics[1].elcr_mask = 0xde;
533 s->irq_request = pic_irq_request;
534 s->irq_request_opaque = kvm;
535 s->pics[0].pics_state = s;
536 s->pics[1].pics_state = s;
539 * Initialize PIO device
541 kvm_iodevice_init(&s->dev, &picdev_ops);
542 ret = kvm_io_bus_register_dev(kvm, &kvm->pio_bus, &s->dev);