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/* $OpenBSD: i8253.c,v 1.17 2017/08/14 19:46:44 jasper Exp $ */ |
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/* |
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* Copyright (c) 2016 Mike Larkin <mlarkin@openbsd.org> |
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* |
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* Permission to use, copy, modify, and distribute this software for any |
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* purpose with or without fee is hereby granted, provided that the above |
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* copyright notice and this permission notice appear in all copies. |
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* |
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
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*/ |
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#include <sys/time.h> |
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#include <sys/types.h> |
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#include <dev/ic/i8253reg.h> |
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#include <machine/vmmvar.h> |
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#include <event.h> |
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#include <string.h> |
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#include <stddef.h> |
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#include <unistd.h> |
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#include "i8253.h" |
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#include "proc.h" |
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#include "vmm.h" |
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#include "atomicio.h" |
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extern char *__progname; |
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/* |
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* Channel 0 is used to generate the legacy hardclock interrupt (HZ). |
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* Channels 1 and 2 are not connected to any output (although someone |
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* could hook channel 2 up to an emulated pcppi(4) at some point). |
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*/ |
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struct i8253_channel i8253_channel[3]; |
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/* |
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* i8253_init |
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* |
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* Initialize the emulated i8253 PIT. |
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* |
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* Parameters: |
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* vm_id: vmm(4)-assigned ID of the VM |
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*/ |
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void |
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i8253_init(uint32_t vm_id) |
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{ |
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memset(&i8253_channel, 0, sizeof(struct i8253_channel)); |
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gettimeofday(&i8253_channel[0].tv, NULL); |
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i8253_channel[0].start = 0xFFFF; |
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i8253_channel[0].mode = TIMER_INTTC; |
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i8253_channel[0].last_r = 1; |
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i8253_channel[0].vm_id = vm_id; |
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i8253_channel[1].start = 0xFFFF; |
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i8253_channel[1].mode = TIMER_INTTC; |
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i8253_channel[1].last_r = 1; |
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i8253_channel[1].vm_id = vm_id; |
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i8253_channel[2].start = 0xFFFF; |
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i8253_channel[2].mode = TIMER_INTTC; |
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i8253_channel[2].last_r = 1; |
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i8253_channel[2].vm_id = vm_id; |
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evtimer_set(&i8253_channel[0].timer, i8253_fire, &i8253_channel[0]); |
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evtimer_set(&i8253_channel[1].timer, i8253_fire, &i8253_channel[1]); |
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evtimer_set(&i8253_channel[2].timer, i8253_fire, &i8253_channel[2]); |
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} |
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/* |
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* i8253_do_readback |
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* |
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* Handles the readback status command. The readback status command latches |
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* the current counter value plus various status bits. |
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* |
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* Parameters: |
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* data: The command word written by the guest VM |
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*/ |
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void |
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i8253_do_readback(uint32_t data) |
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{ |
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struct timeval now, delta; |
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uint64_t ns, ticks; |
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/* bits are inverted here - !TIMER_RB_STATUS == enable chan readback */ |
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if (data & ~TIMER_RB_STATUS) { |
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i8253_channel[0].rbs = (data & TIMER_RB_C0) ? 1 : 0; |
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i8253_channel[1].rbs = (data & TIMER_RB_C1) ? 1 : 0; |
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i8253_channel[2].rbs = (data & TIMER_RB_C2) ? 1 : 0; |
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} |
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/* !TIMER_RB_COUNT == enable counter readback */ |
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if (data & ~TIMER_RB_COUNT) { |
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if (data & TIMER_RB_C0) { |
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gettimeofday(&now, NULL); |
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delta.tv_sec = now.tv_sec - i8253_channel[0].tv.tv_sec; |
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delta.tv_usec = now.tv_usec - |
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i8253_channel[0].tv.tv_usec; |
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if (delta.tv_usec < 0) { |
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delta.tv_sec--; |
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delta.tv_usec += 1000000; |
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} |
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if (delta.tv_usec > 1000000) { |
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delta.tv_sec++; |
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delta.tv_usec -= 1000000; |
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} |
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ns = delta.tv_usec * 1000 + delta.tv_sec * 1000000000; |
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ticks = ns / NS_PER_TICK; |
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if (i8253_channel[0].start) |
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i8253_channel[0].olatch = |
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i8253_channel[0].start - |
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ticks % i8253_channel[0].start; |
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else |
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i8253_channel[0].olatch = 0; |
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} |
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if (data & TIMER_RB_C1) { |
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gettimeofday(&now, NULL); |
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delta.tv_sec = now.tv_sec - i8253_channel[1].tv.tv_sec; |
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delta.tv_usec = now.tv_usec - |
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i8253_channel[1].tv.tv_usec; |
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if (delta.tv_usec < 0) { |
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delta.tv_sec--; |
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delta.tv_usec += 1000000; |
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} |
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if (delta.tv_usec > 1000000) { |
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delta.tv_sec++; |
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delta.tv_usec -= 1000000; |
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} |
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ns = delta.tv_usec * 1000 + delta.tv_sec * 1000000000; |
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ticks = ns / NS_PER_TICK; |
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if (i8253_channel[1].start) |
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i8253_channel[1].olatch = |
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i8253_channel[1].start - |
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ticks % i8253_channel[1].start; |
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else |
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i8253_channel[1].olatch = 0; |
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} |
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if (data & TIMER_RB_C2) { |
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gettimeofday(&now, NULL); |
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delta.tv_sec = now.tv_sec - i8253_channel[2].tv.tv_sec; |
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delta.tv_usec = now.tv_usec - |
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i8253_channel[2].tv.tv_usec; |
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if (delta.tv_usec < 0) { |
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delta.tv_sec--; |
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delta.tv_usec += 1000000; |
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} |
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if (delta.tv_usec > 1000000) { |
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delta.tv_sec++; |
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delta.tv_usec -= 1000000; |
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} |
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ns = delta.tv_usec * 1000 + delta.tv_sec * 1000000000; |
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ticks = ns / NS_PER_TICK; |
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if (i8253_channel[2].start) |
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i8253_channel[2].olatch = |
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i8253_channel[2].start - |
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ticks % i8253_channel[2].start; |
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else |
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i8253_channel[2].olatch = 0; |
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} |
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} |
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} |
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/* |
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* vcpu_exit_i8253 |
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* |
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* Handles emulated i8253 PIT access (in/out instruction to PIT ports). |
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* |
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* Parameters: |
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* vrp: vm run parameters containing exit information for the I/O |
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* instruction being performed |
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* |
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* Return value: |
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* Interrupt to inject to the guest VM, or 0xFF if no interrupt should |
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* be injected. |
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*/ |
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uint8_t |
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vcpu_exit_i8253(struct vm_run_params *vrp) |
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{ |
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uint32_t out_data; |
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uint8_t sel, rw, data, mode; |
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uint64_t ns, ticks; |
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struct timeval now, delta; |
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union vm_exit *vei = vrp->vrp_exit; |
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get_input_data(vei, &out_data); |
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if (vei->vei.vei_port == TIMER_CTRL) { |
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if (vei->vei.vei_dir == VEI_DIR_OUT) { /* OUT instruction */ |
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sel = out_data & |
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(TIMER_SEL0 | TIMER_SEL1 | TIMER_SEL2); |
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sel = sel >> 6; |
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if (sel == 3) { |
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i8253_do_readback(out_data); |
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return (0xFF); |
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} |
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rw = out_data & (TIMER_LATCH | TIMER_16BIT); |
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/* |
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* Since we don't truly emulate each tick of the PIT |
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* counter, when the guest asks for the timer to be |
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* latched, simulate what the counter would have been |
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* had we performed full emulation. We do this by |
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* calculating when the counter was reset vs how much |
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* time has elapsed, then bias by the counter tick |
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* rate. |
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*/ |
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if (rw == TIMER_LATCH) { |
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gettimeofday(&now, NULL); |
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delta.tv_sec = now.tv_sec - |
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i8253_channel[sel].tv.tv_sec; |
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delta.tv_usec = now.tv_usec - |
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i8253_channel[sel].tv.tv_usec; |
224 |
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if (delta.tv_usec < 0) { |
225 |
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delta.tv_sec--; |
226 |
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delta.tv_usec += 1000000; |
227 |
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} |
228 |
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if (delta.tv_usec > 1000000) { |
229 |
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delta.tv_sec++; |
230 |
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delta.tv_usec -= 1000000; |
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} |
232 |
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ns = delta.tv_usec * 1000 + |
233 |
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delta.tv_sec * 1000000000; |
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ticks = ns / NS_PER_TICK; |
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if (i8253_channel[sel].start) { |
236 |
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i8253_channel[sel].olatch = |
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i8253_channel[sel].start - |
238 |
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ticks % i8253_channel[sel].start; |
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} else |
240 |
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i8253_channel[sel].olatch = 0; |
241 |
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goto ret; |
242 |
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} else if (rw != TIMER_16BIT) { |
243 |
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log_warnx("%s: i8253 PIT: unsupported counter " |
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"%d rw mode 0x%x selected", __func__, |
245 |
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sel, (rw & TIMER_16BIT)); |
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} |
247 |
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248 |
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goto ret; |
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} else { |
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log_warnx("%s: i8253 PIT: read from control port " |
251 |
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"unsupported", __progname); |
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set_return_data(vei, 0); |
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} |
254 |
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} else { |
255 |
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sel = vei->vei.vei_port - (TIMER_CNTR0 + TIMER_BASE); |
256 |
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257 |
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if (vei->vei.vei_dir == VEI_DIR_OUT) { /* OUT instruction */ |
258 |
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if (i8253_channel[sel].last_w == 0) { |
259 |
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i8253_channel[sel].ilatch |= (out_data & 0xff); |
260 |
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i8253_channel[sel].last_w = 1; |
261 |
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} else { |
262 |
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i8253_channel[sel].ilatch |= ((out_data & 0xff) << 8); |
263 |
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i8253_channel[sel].start = |
264 |
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i8253_channel[sel].ilatch; |
265 |
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i8253_channel[sel].last_w = 0; |
266 |
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mode = (out_data & 0xe) >> 1; |
267 |
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268 |
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if (i8253_channel[sel].start == 0) |
269 |
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i8253_channel[sel].start = 0xffff; |
270 |
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271 |
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log_debug("%s: channel %d reset, mode=%d, start=%d", __func__, |
272 |
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sel, mode, i8253_channel[sel].start); |
273 |
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i8253_channel[sel].mode = mode; |
274 |
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i8253_reset(sel); |
275 |
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} |
276 |
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} else { |
277 |
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if (i8253_channel[sel].rbs) { |
278 |
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i8253_channel[sel].rbs = 0; |
279 |
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data = i8253_channel[sel].mode << 1; |
280 |
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data |= TIMER_16BIT; |
281 |
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set_return_data(vei, data); |
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goto ret; |
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} |
284 |
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285 |
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if (i8253_channel[sel].last_r == 0) { |
286 |
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data = i8253_channel[sel].olatch >> 8; |
287 |
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set_return_data(vei, data); |
288 |
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i8253_channel[sel].last_r = 1; |
289 |
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} else { |
290 |
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data = i8253_channel[sel].olatch & 0xFF; |
291 |
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set_return_data(vei, data); |
292 |
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i8253_channel[sel].last_r = 0; |
293 |
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} |
294 |
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} |
295 |
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} |
296 |
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297 |
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ret: |
298 |
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return (0xFF); |
299 |
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} |
300 |
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301 |
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/* |
302 |
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* i8253_reset |
303 |
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* |
304 |
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* Resets the i8253's counter timer |
305 |
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* |
306 |
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* Parameters: |
307 |
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* chn: counter ID. Only channel ID 0 is presently emulated. |
308 |
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*/ |
309 |
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void |
310 |
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i8253_reset(uint8_t chn) |
311 |
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{ |
312 |
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struct timeval tv; |
313 |
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314 |
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evtimer_del(&i8253_channel[chn].timer); |
315 |
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timerclear(&tv); |
316 |
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317 |
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i8253_channel[chn].in_use = 1; |
318 |
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tv.tv_usec = (i8253_channel[chn].start * NS_PER_TICK) / 1000; |
319 |
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evtimer_add(&i8253_channel[chn].timer, &tv); |
320 |
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} |
321 |
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|
322 |
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/* |
323 |
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* i8253_fire |
324 |
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* |
325 |
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* Callback invoked when the 8253 PIT timer fires. This will assert |
326 |
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* IRQ0 on the legacy PIC attached to VCPU0. |
327 |
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* |
328 |
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* Parameters: |
329 |
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* fd: unused |
330 |
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* type: unused |
331 |
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* arg: VM ID |
332 |
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*/ |
333 |
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void |
334 |
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i8253_fire(int fd, short type, void *arg) |
335 |
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{ |
336 |
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struct timeval tv; |
337 |
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struct i8253_channel *ctr = (struct i8253_channel *)arg; |
338 |
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|
339 |
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timerclear(&tv); |
340 |
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tv.tv_usec = (ctr->start * NS_PER_TICK) / 1000; |
341 |
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342 |
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vcpu_assert_pic_irq(ctr->vm_id, 0, 0); |
343 |
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|
344 |
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if (ctr->mode != TIMER_INTTC) |
345 |
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evtimer_add(&ctr->timer, &tv); |
346 |
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} |
347 |
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|
348 |
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int |
349 |
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i8253_dump(int fd) |
350 |
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{ |
351 |
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log_debug("%s: sending PIT", __func__); |
352 |
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if (atomicio(vwrite, fd, &i8253_channel, sizeof(i8253_channel)) != |
353 |
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sizeof(i8253_channel)) { |
354 |
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log_warnx("%s: error writing PIT to fd", __func__); |
355 |
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return (-1); |
356 |
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} |
357 |
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return (0); |
358 |
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} |
359 |
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|
360 |
|
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int |
361 |
|
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i8253_restore(int fd, uint32_t vm_id) |
362 |
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{ |
363 |
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int i; |
364 |
|
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log_debug("%s: restoring PIT", __func__); |
365 |
|
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if (atomicio(read, fd, &i8253_channel, sizeof(i8253_channel)) != |
366 |
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sizeof(i8253_channel)) { |
367 |
|
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log_warnx("%s: error reading PIT from fd", __func__); |
368 |
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return (-1); |
369 |
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} |
370 |
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|
371 |
|
|
for (i = 0; i < 3; i++) { |
372 |
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memset(&i8253_channel[i].timer, 0, sizeof(struct event)); |
373 |
|
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i8253_channel[i].vm_id = vm_id; |
374 |
|
|
evtimer_set(&i8253_channel[i].timer, i8253_fire, |
375 |
|
|
&i8253_channel[i]); |
376 |
|
|
i8253_reset(i); |
377 |
|
|
} |
378 |
|
|
return (0); |
379 |
|
|
} |
380 |
|
|
|
381 |
|
|
void |
382 |
|
|
i8253_stop() |
383 |
|
|
{ |
384 |
|
|
int i; |
385 |
|
|
for (i = 0; i < 3; i++) |
386 |
|
|
evtimer_del(&i8253_channel[i].timer); |
387 |
|
|
} |
388 |
|
|
|
389 |
|
|
void |
390 |
|
|
i8253_start() |
391 |
|
|
{ |
392 |
|
|
int i; |
393 |
|
|
for (i = 0; i < 3; i++) |
394 |
|
|
if(i8253_channel[i].in_use) |
395 |
|
|
i8253_reset(i); |
396 |
|
|
} |