| /* |
| * 8253/8254 interval timer emulation |
| * |
| * Copyright (c) 2003-2004 Fabrice Bellard |
| * Copyright (c) 2006 Intel Corporation |
| * Copyright (c) 2007 Keir Fraser, XenSource Inc |
| * Copyright (c) 2008 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: |
| * Sheng Yang <sheng.yang@intel.com> |
| * Based on QEMU and Xen. |
| */ |
| |
| #include <linux/kvm_host.h> |
| |
| #include "irq.h" |
| #include "i8254.h" |
| |
| #ifndef CONFIG_X86_64 |
| #define mod_64(x, y) ((x) - (y) * div64_u64(x, y)) |
| #else |
| #define mod_64(x, y) ((x) % (y)) |
| #endif |
| |
| #define RW_STATE_LSB 1 |
| #define RW_STATE_MSB 2 |
| #define RW_STATE_WORD0 3 |
| #define RW_STATE_WORD1 4 |
| |
| /* Compute with 96 bit intermediate result: (a*b)/c */ |
| static u64 muldiv64(u64 a, u32 b, u32 c) |
| { |
| union { |
| u64 ll; |
| struct { |
| u32 low, high; |
| } l; |
| } u, res; |
| u64 rl, rh; |
| |
| u.ll = a; |
| rl = (u64)u.l.low * (u64)b; |
| rh = (u64)u.l.high * (u64)b; |
| rh += (rl >> 32); |
| res.l.high = div64_u64(rh, c); |
| res.l.low = div64_u64(((mod_64(rh, c) << 32) + (rl & 0xffffffff)), c); |
| return res.ll; |
| } |
| |
| static void pit_set_gate(struct kvm *kvm, int channel, u32 val) |
| { |
| struct kvm_kpit_channel_state *c = |
| &kvm->arch.vpit->pit_state.channels[channel]; |
| |
| WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock)); |
| |
| switch (c->mode) { |
| default: |
| case 0: |
| case 4: |
| /* XXX: just disable/enable counting */ |
| break; |
| case 1: |
| case 2: |
| case 3: |
| case 5: |
| /* Restart counting on rising edge. */ |
| if (c->gate < val) |
| c->count_load_time = ktime_get(); |
| break; |
| } |
| |
| c->gate = val; |
| } |
| |
| int pit_get_gate(struct kvm *kvm, int channel) |
| { |
| WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock)); |
| |
| return kvm->arch.vpit->pit_state.channels[channel].gate; |
| } |
| |
| static int pit_get_count(struct kvm *kvm, int channel) |
| { |
| struct kvm_kpit_channel_state *c = |
| &kvm->arch.vpit->pit_state.channels[channel]; |
| s64 d, t; |
| int counter; |
| |
| WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock)); |
| |
| t = ktime_to_ns(ktime_sub(ktime_get(), c->count_load_time)); |
| d = muldiv64(t, KVM_PIT_FREQ, NSEC_PER_SEC); |
| |
| switch (c->mode) { |
| case 0: |
| case 1: |
| case 4: |
| case 5: |
| counter = (c->count - d) & 0xffff; |
| break; |
| case 3: |
| /* XXX: may be incorrect for odd counts */ |
| counter = c->count - (mod_64((2 * d), c->count)); |
| break; |
| default: |
| counter = c->count - mod_64(d, c->count); |
| break; |
| } |
| return counter; |
| } |
| |
| static int pit_get_out(struct kvm *kvm, int channel) |
| { |
| struct kvm_kpit_channel_state *c = |
| &kvm->arch.vpit->pit_state.channels[channel]; |
| s64 d, t; |
| int out; |
| |
| WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock)); |
| |
| t = ktime_to_ns(ktime_sub(ktime_get(), c->count_load_time)); |
| d = muldiv64(t, KVM_PIT_FREQ, NSEC_PER_SEC); |
| |
| switch (c->mode) { |
| default: |
| case 0: |
| out = (d >= c->count); |
| break; |
| case 1: |
| out = (d < c->count); |
| break; |
| case 2: |
| out = ((mod_64(d, c->count) == 0) && (d != 0)); |
| break; |
| case 3: |
| out = (mod_64(d, c->count) < ((c->count + 1) >> 1)); |
| break; |
| case 4: |
| case 5: |
| out = (d == c->count); |
| break; |
| } |
| |
| return out; |
| } |
| |
| static void pit_latch_count(struct kvm *kvm, int channel) |
| { |
| struct kvm_kpit_channel_state *c = |
| &kvm->arch.vpit->pit_state.channels[channel]; |
| |
| WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock)); |
| |
| if (!c->count_latched) { |
| c->latched_count = pit_get_count(kvm, channel); |
| c->count_latched = c->rw_mode; |
| } |
| } |
| |
| static void pit_latch_status(struct kvm *kvm, int channel) |
| { |
| struct kvm_kpit_channel_state *c = |
| &kvm->arch.vpit->pit_state.channels[channel]; |
| |
| WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock)); |
| |
| if (!c->status_latched) { |
| /* TODO: Return NULL COUNT (bit 6). */ |
| c->status = ((pit_get_out(kvm, channel) << 7) | |
| (c->rw_mode << 4) | |
| (c->mode << 1) | |
| c->bcd); |
| c->status_latched = 1; |
| } |
| } |
| |
| int __pit_timer_fn(struct kvm_kpit_state *ps) |
| { |
| struct kvm_vcpu *vcpu0 = ps->pit->kvm->vcpus[0]; |
| struct kvm_kpit_timer *pt = &ps->pit_timer; |
| |
| atomic_inc(&pt->pending); |
| smp_mb__after_atomic_inc(); |
| if (vcpu0 && waitqueue_active(&vcpu0->wq)) { |
| vcpu0->arch.mp_state = KVM_MP_STATE_RUNNABLE; |
| wake_up_interruptible(&vcpu0->wq); |
| } |
| |
| pt->timer.expires = ktime_add_ns(pt->timer.expires, pt->period); |
| pt->scheduled = ktime_to_ns(pt->timer.expires); |
| |
| return (pt->period == 0 ? 0 : 1); |
| } |
| |
| int pit_has_pending_timer(struct kvm_vcpu *vcpu) |
| { |
| struct kvm_pit *pit = vcpu->kvm->arch.vpit; |
| |
| if (pit && vcpu->vcpu_id == 0 && pit->pit_state.inject_pending) |
| return atomic_read(&pit->pit_state.pit_timer.pending); |
| |
| return 0; |
| } |
| |
| static enum hrtimer_restart pit_timer_fn(struct hrtimer *data) |
| { |
| struct kvm_kpit_state *ps; |
| int restart_timer = 0; |
| |
| ps = container_of(data, struct kvm_kpit_state, pit_timer.timer); |
| |
| restart_timer = __pit_timer_fn(ps); |
| |
| if (restart_timer) |
| return HRTIMER_RESTART; |
| else |
| return HRTIMER_NORESTART; |
| } |
| |
| void __kvm_migrate_pit_timer(struct kvm_vcpu *vcpu) |
| { |
| struct kvm_pit *pit = vcpu->kvm->arch.vpit; |
| struct hrtimer *timer; |
| |
| if (vcpu->vcpu_id != 0 || !pit) |
| return; |
| |
| timer = &pit->pit_state.pit_timer.timer; |
| if (hrtimer_cancel(timer)) |
| hrtimer_start(timer, timer->expires, HRTIMER_MODE_ABS); |
| } |
| |
| static void destroy_pit_timer(struct kvm_kpit_timer *pt) |
| { |
| pr_debug("pit: execute del timer!\n"); |
| hrtimer_cancel(&pt->timer); |
| } |
| |
| static void create_pit_timer(struct kvm_kpit_timer *pt, u32 val, int is_period) |
| { |
| s64 interval; |
| |
| interval = muldiv64(val, NSEC_PER_SEC, KVM_PIT_FREQ); |
| |
| pr_debug("pit: create pit timer, interval is %llu nsec\n", interval); |
| |
| /* TODO The new value only affected after the retriggered */ |
| hrtimer_cancel(&pt->timer); |
| pt->period = (is_period == 0) ? 0 : interval; |
| pt->timer.function = pit_timer_fn; |
| atomic_set(&pt->pending, 0); |
| |
| hrtimer_start(&pt->timer, ktime_add_ns(ktime_get(), interval), |
| HRTIMER_MODE_ABS); |
| } |
| |
| static void pit_load_count(struct kvm *kvm, int channel, u32 val) |
| { |
| struct kvm_kpit_state *ps = &kvm->arch.vpit->pit_state; |
| |
| WARN_ON(!mutex_is_locked(&ps->lock)); |
| |
| pr_debug("pit: load_count val is %d, channel is %d\n", val, channel); |
| |
| /* |
| * Though spec said the state of 8254 is undefined after power-up, |
| * seems some tricky OS like Windows XP depends on IRQ0 interrupt |
| * when booting up. |
| * So here setting initialize rate for it, and not a specific number |
| */ |
| if (val == 0) |
| val = 0x10000; |
| |
| ps->channels[channel].count_load_time = ktime_get(); |
| ps->channels[channel].count = val; |
| |
| if (channel != 0) |
| return; |
| |
| /* Two types of timer |
| * mode 1 is one shot, mode 2 is period, otherwise del timer */ |
| switch (ps->channels[0].mode) { |
| case 1: |
| /* FIXME: enhance mode 4 precision */ |
| case 4: |
| create_pit_timer(&ps->pit_timer, val, 0); |
| break; |
| case 2: |
| create_pit_timer(&ps->pit_timer, val, 1); |
| break; |
| default: |
| destroy_pit_timer(&ps->pit_timer); |
| } |
| } |
| |
| void kvm_pit_load_count(struct kvm *kvm, int channel, u32 val) |
| { |
| mutex_lock(&kvm->arch.vpit->pit_state.lock); |
| pit_load_count(kvm, channel, val); |
| mutex_unlock(&kvm->arch.vpit->pit_state.lock); |
| } |
| |
| static void pit_ioport_write(struct kvm_io_device *this, |
| gpa_t addr, int len, const void *data) |
| { |
| struct kvm_pit *pit = (struct kvm_pit *)this->private; |
| struct kvm_kpit_state *pit_state = &pit->pit_state; |
| struct kvm *kvm = pit->kvm; |
| int channel, access; |
| struct kvm_kpit_channel_state *s; |
| u32 val = *(u32 *) data; |
| |
| val &= 0xff; |
| addr &= KVM_PIT_CHANNEL_MASK; |
| |
| mutex_lock(&pit_state->lock); |
| |
| if (val != 0) |
| pr_debug("pit: write addr is 0x%x, len is %d, val is 0x%x\n", |
| (unsigned int)addr, len, val); |
| |
| if (addr == 3) { |
| channel = val >> 6; |
| if (channel == 3) { |
| /* Read-Back Command. */ |
| for (channel = 0; channel < 3; channel++) { |
| s = &pit_state->channels[channel]; |
| if (val & (2 << channel)) { |
| if (!(val & 0x20)) |
| pit_latch_count(kvm, channel); |
| if (!(val & 0x10)) |
| pit_latch_status(kvm, channel); |
| } |
| } |
| } else { |
| /* Select Counter <channel>. */ |
| s = &pit_state->channels[channel]; |
| access = (val >> 4) & KVM_PIT_CHANNEL_MASK; |
| if (access == 0) { |
| pit_latch_count(kvm, channel); |
| } else { |
| s->rw_mode = access; |
| s->read_state = access; |
| s->write_state = access; |
| s->mode = (val >> 1) & 7; |
| if (s->mode > 5) |
| s->mode -= 4; |
| s->bcd = val & 1; |
| } |
| } |
| } else { |
| /* Write Count. */ |
| s = &pit_state->channels[addr]; |
| switch (s->write_state) { |
| default: |
| case RW_STATE_LSB: |
| pit_load_count(kvm, addr, val); |
| break; |
| case RW_STATE_MSB: |
| pit_load_count(kvm, addr, val << 8); |
| break; |
| case RW_STATE_WORD0: |
| s->write_latch = val; |
| s->write_state = RW_STATE_WORD1; |
| break; |
| case RW_STATE_WORD1: |
| pit_load_count(kvm, addr, s->write_latch | (val << 8)); |
| s->write_state = RW_STATE_WORD0; |
| break; |
| } |
| } |
| |
| mutex_unlock(&pit_state->lock); |
| } |
| |
| static void pit_ioport_read(struct kvm_io_device *this, |
| gpa_t addr, int len, void *data) |
| { |
| struct kvm_pit *pit = (struct kvm_pit *)this->private; |
| struct kvm_kpit_state *pit_state = &pit->pit_state; |
| struct kvm *kvm = pit->kvm; |
| int ret, count; |
| struct kvm_kpit_channel_state *s; |
| |
| addr &= KVM_PIT_CHANNEL_MASK; |
| s = &pit_state->channels[addr]; |
| |
| mutex_lock(&pit_state->lock); |
| |
| if (s->status_latched) { |
| s->status_latched = 0; |
| ret = s->status; |
| } else if (s->count_latched) { |
| switch (s->count_latched) { |
| default: |
| case RW_STATE_LSB: |
| ret = s->latched_count & 0xff; |
| s->count_latched = 0; |
| break; |
| case RW_STATE_MSB: |
| ret = s->latched_count >> 8; |
| s->count_latched = 0; |
| break; |
| case RW_STATE_WORD0: |
| ret = s->latched_count & 0xff; |
| s->count_latched = RW_STATE_MSB; |
| break; |
| } |
| } else { |
| switch (s->read_state) { |
| default: |
| case RW_STATE_LSB: |
| count = pit_get_count(kvm, addr); |
| ret = count & 0xff; |
| break; |
| case RW_STATE_MSB: |
| count = pit_get_count(kvm, addr); |
| ret = (count >> 8) & 0xff; |
| break; |
| case RW_STATE_WORD0: |
| count = pit_get_count(kvm, addr); |
| ret = count & 0xff; |
| s->read_state = RW_STATE_WORD1; |
| break; |
| case RW_STATE_WORD1: |
| count = pit_get_count(kvm, addr); |
| ret = (count >> 8) & 0xff; |
| s->read_state = RW_STATE_WORD0; |
| break; |
| } |
| } |
| |
| if (len > sizeof(ret)) |
| len = sizeof(ret); |
| memcpy(data, (char *)&ret, len); |
| |
| mutex_unlock(&pit_state->lock); |
| } |
| |
| static int pit_in_range(struct kvm_io_device *this, gpa_t addr) |
| { |
| return ((addr >= KVM_PIT_BASE_ADDRESS) && |
| (addr < KVM_PIT_BASE_ADDRESS + KVM_PIT_MEM_LENGTH)); |
| } |
| |
| static void speaker_ioport_write(struct kvm_io_device *this, |
| gpa_t addr, int len, const void *data) |
| { |
| struct kvm_pit *pit = (struct kvm_pit *)this->private; |
| struct kvm_kpit_state *pit_state = &pit->pit_state; |
| struct kvm *kvm = pit->kvm; |
| u32 val = *(u32 *) data; |
| |
| mutex_lock(&pit_state->lock); |
| pit_state->speaker_data_on = (val >> 1) & 1; |
| pit_set_gate(kvm, 2, val & 1); |
| mutex_unlock(&pit_state->lock); |
| } |
| |
| static void speaker_ioport_read(struct kvm_io_device *this, |
| gpa_t addr, int len, void *data) |
| { |
| struct kvm_pit *pit = (struct kvm_pit *)this->private; |
| struct kvm_kpit_state *pit_state = &pit->pit_state; |
| struct kvm *kvm = pit->kvm; |
| unsigned int refresh_clock; |
| int ret; |
| |
| /* Refresh clock toggles at about 15us. We approximate as 2^14ns. */ |
| refresh_clock = ((unsigned int)ktime_to_ns(ktime_get()) >> 14) & 1; |
| |
| mutex_lock(&pit_state->lock); |
| ret = ((pit_state->speaker_data_on << 1) | pit_get_gate(kvm, 2) | |
| (pit_get_out(kvm, 2) << 5) | (refresh_clock << 4)); |
| if (len > sizeof(ret)) |
| len = sizeof(ret); |
| memcpy(data, (char *)&ret, len); |
| mutex_unlock(&pit_state->lock); |
| } |
| |
| static int speaker_in_range(struct kvm_io_device *this, gpa_t addr) |
| { |
| return (addr == KVM_SPEAKER_BASE_ADDRESS); |
| } |
| |
| void kvm_pit_reset(struct kvm_pit *pit) |
| { |
| int i; |
| struct kvm_kpit_channel_state *c; |
| |
| mutex_lock(&pit->pit_state.lock); |
| for (i = 0; i < 3; i++) { |
| c = &pit->pit_state.channels[i]; |
| c->mode = 0xff; |
| c->gate = (i != 2); |
| pit_load_count(pit->kvm, i, 0); |
| } |
| mutex_unlock(&pit->pit_state.lock); |
| |
| atomic_set(&pit->pit_state.pit_timer.pending, 0); |
| pit->pit_state.inject_pending = 1; |
| } |
| |
| struct kvm_pit *kvm_create_pit(struct kvm *kvm) |
| { |
| struct kvm_pit *pit; |
| struct kvm_kpit_state *pit_state; |
| |
| pit = kzalloc(sizeof(struct kvm_pit), GFP_KERNEL); |
| if (!pit) |
| return NULL; |
| |
| mutex_init(&pit->pit_state.lock); |
| mutex_lock(&pit->pit_state.lock); |
| |
| /* Initialize PIO device */ |
| pit->dev.read = pit_ioport_read; |
| pit->dev.write = pit_ioport_write; |
| pit->dev.in_range = pit_in_range; |
| pit->dev.private = pit; |
| kvm_io_bus_register_dev(&kvm->pio_bus, &pit->dev); |
| |
| pit->speaker_dev.read = speaker_ioport_read; |
| pit->speaker_dev.write = speaker_ioport_write; |
| pit->speaker_dev.in_range = speaker_in_range; |
| pit->speaker_dev.private = pit; |
| kvm_io_bus_register_dev(&kvm->pio_bus, &pit->speaker_dev); |
| |
| kvm->arch.vpit = pit; |
| pit->kvm = kvm; |
| |
| pit_state = &pit->pit_state; |
| pit_state->pit = pit; |
| hrtimer_init(&pit_state->pit_timer.timer, |
| CLOCK_MONOTONIC, HRTIMER_MODE_ABS); |
| mutex_unlock(&pit->pit_state.lock); |
| |
| kvm_pit_reset(pit); |
| |
| return pit; |
| } |
| |
| void kvm_free_pit(struct kvm *kvm) |
| { |
| struct hrtimer *timer; |
| |
| if (kvm->arch.vpit) { |
| mutex_lock(&kvm->arch.vpit->pit_state.lock); |
| timer = &kvm->arch.vpit->pit_state.pit_timer.timer; |
| hrtimer_cancel(timer); |
| mutex_unlock(&kvm->arch.vpit->pit_state.lock); |
| kfree(kvm->arch.vpit); |
| } |
| } |
| |
| void __inject_pit_timer_intr(struct kvm *kvm) |
| { |
| mutex_lock(&kvm->lock); |
| kvm_ioapic_set_irq(kvm->arch.vioapic, 0, 1); |
| kvm_ioapic_set_irq(kvm->arch.vioapic, 0, 0); |
| kvm_pic_set_irq(pic_irqchip(kvm), 0, 1); |
| kvm_pic_set_irq(pic_irqchip(kvm), 0, 0); |
| mutex_unlock(&kvm->lock); |
| } |
| |
| void kvm_inject_pit_timer_irqs(struct kvm_vcpu *vcpu) |
| { |
| struct kvm_pit *pit = vcpu->kvm->arch.vpit; |
| struct kvm *kvm = vcpu->kvm; |
| struct kvm_kpit_state *ps; |
| |
| if (vcpu && pit) { |
| ps = &pit->pit_state; |
| |
| /* Try to inject pending interrupts when: |
| * 1. Pending exists |
| * 2. Last interrupt was accepted or waited for too long time*/ |
| if (atomic_read(&ps->pit_timer.pending) && |
| (ps->inject_pending || |
| (jiffies - ps->last_injected_time |
| >= KVM_MAX_PIT_INTR_INTERVAL))) { |
| ps->inject_pending = 0; |
| __inject_pit_timer_intr(kvm); |
| ps->last_injected_time = jiffies; |
| } |
| } |
| } |
| |
| void kvm_pit_timer_intr_post(struct kvm_vcpu *vcpu, int vec) |
| { |
| struct kvm_arch *arch = &vcpu->kvm->arch; |
| struct kvm_kpit_state *ps; |
| |
| if (vcpu && arch->vpit) { |
| ps = &arch->vpit->pit_state; |
| if (atomic_read(&ps->pit_timer.pending) && |
| (((arch->vpic->pics[0].imr & 1) == 0 && |
| arch->vpic->pics[0].irq_base == vec) || |
| (arch->vioapic->redirtbl[0].fields.vector == vec && |
| arch->vioapic->redirtbl[0].fields.mask != 1))) { |
| ps->inject_pending = 1; |
| atomic_dec(&ps->pit_timer.pending); |
| ps->channels[0].count_load_time = ktime_get(); |
| } |
| } |
| } |