/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2014 Hudson River Trading LLC
* Written by: John H. Baldwin <jhb@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <machine/vmm.h>
#include <assert.h>
#include <pthread.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <vmmapi.h>
#include "acpi.h"
#include "inout.h"
#include "pci_emul.h"
#include "pci_irq.h"
#include "pci_lpc.h"
/*
* Implement an 8 pin PCI interrupt router compatible with the router
* present on Intel's ICH10 chip.
*/
/* Fields in each PIRQ register. */
#define PIRQ_DIS 0x80
#define PIRQ_IRQ 0x0f
/* Only IRQs 3-7, 9-12, and 14-15 are permitted. */
#define PERMITTED_IRQS 0xdef8
#define IRQ_PERMITTED(irq) (((1U << (irq)) & PERMITTED_IRQS) != 0)
/* IRQ count to disable an IRQ. */
#define IRQ_DISABLED 0xff
static struct pirq {
uint8_t reg;
int use_count;
int active_count;
pthread_mutex_t lock;
} pirqs[8];
static u_char irq_counts[16];
static int pirq_cold = 1;
/*
* Returns true if this pin is enabled with a valid IRQ. Setting the
* register to a reserved IRQ causes interrupts to not be asserted as
* if the pin was disabled.
*/
static bool
pirq_valid_irq(int reg)
{
if (reg & PIRQ_DIS)
return (false);
return (IRQ_PERMITTED(reg & PIRQ_IRQ));
}
uint8_t
pirq_read(int pin)
{
assert(pin > 0 && pin <= nitems(pirqs));
return (pirqs[pin - 1].reg);
}
void
pirq_write(struct vmctx *ctx, int pin, uint8_t val)
{
struct pirq *pirq;
assert(pin > 0 && pin <= nitems(pirqs));
pirq = &pirqs[pin - 1];
pthread_mutex_lock(&pirq->lock);
if (pirq->reg != (val & (PIRQ_DIS | PIRQ_IRQ))) {
if (pirq->active_count != 0 && pirq_valid_irq(pirq->reg))
vm_isa_deassert_irq(ctx, pirq->reg & PIRQ_IRQ, -1);
pirq->reg = val & (PIRQ_DIS | PIRQ_IRQ);
if (pirq->active_count != 0 && pirq_valid_irq(pirq->reg))
vm_isa_assert_irq(ctx, pirq->reg & PIRQ_IRQ, -1);
}
pthread_mutex_unlock(&pirq->lock);
}
void
pci_irq_reserve(int irq)
{
assert(irq >= 0 && irq < nitems(irq_counts));
assert(pirq_cold);
assert(irq_counts[irq] == 0 || irq_counts[irq] == IRQ_DISABLED);
irq_counts[irq] = IRQ_DISABLED;
}
void
pci_irq_use(int irq)
{
assert(irq >= 0 && irq < nitems(irq_counts));
assert(pirq_cold);
assert(irq_counts[irq] != IRQ_DISABLED);
irq_counts[irq]++;
}
void
pci_irq_init(struct vmctx *ctx)
{
int i;
for (i = 0; i < nitems(pirqs); i++) {
pirqs[i].reg = PIRQ_DIS;
pirqs[i].use_count = 0;
pirqs[i].active_count = 0;
pthread_mutex_init(&pirqs[i].lock, NULL);
}
for (i = 0; i < nitems(irq_counts); i++) {
if (IRQ_PERMITTED(i))
irq_counts[i] = 0;
else
irq_counts[i] = IRQ_DISABLED;
}
}
void
pci_irq_assert(struct pci_devinst *pi)
{
struct pirq *pirq;
if (pi->pi_lintr.pirq_pin > 0) {
assert(pi->pi_lintr.pirq_pin <= nitems(pirqs));
pirq = &pirqs[pi->pi_lintr.pirq_pin - 1];
pthread_mutex_lock(&pirq->lock);
pirq->active_count++;
if (pirq->active_count == 1 && pirq_valid_irq(pirq->reg)) {
vm_isa_assert_irq(pi->pi_vmctx, pirq->reg & PIRQ_IRQ,
pi->pi_lintr.ioapic_irq);
pthread_mutex_unlock(&pirq->lock);
return;
}
pthread_mutex_unlock(&pirq->lock);
}
vm_ioapic_assert_irq(pi->pi_vmctx, pi->pi_lintr.ioapic_irq);
}
void
pci_irq_deassert(struct pci_devinst *pi)
{
struct pirq *pirq;
if (pi->pi_lintr.pirq_pin > 0) {
assert(pi->pi_lintr.pirq_pin <= nitems(pirqs));
pirq = &pirqs[pi->pi_lintr.pirq_pin - 1];
pthread_mutex_lock(&pirq->lock);
pirq->active_count--;
if (pirq->active_count == 0 && pirq_valid_irq(pirq->reg)) {
vm_isa_deassert_irq(pi->pi_vmctx, pirq->reg & PIRQ_IRQ,
pi->pi_lintr.ioapic_irq);
pthread_mutex_unlock(&pirq->lock);
return;
}
pthread_mutex_unlock(&pirq->lock);
}
vm_ioapic_deassert_irq(pi->pi_vmctx, pi->pi_lintr.ioapic_irq);
}
int
pirq_alloc_pin(struct pci_devinst *pi)
{
struct vmctx *ctx = pi->pi_vmctx;
int best_count, best_irq, best_pin, irq, pin;
pirq_cold = 0;
if (lpc_bootrom()) {
/* For external bootrom use fixed mapping. */
best_pin = (4 + pi->pi_slot + pi->pi_lintr.pin) % 8;
} else {
/* Find the least-used PIRQ pin. */
best_pin = 0;
best_count = pirqs[0].use_count;
for (pin = 1; pin < nitems(pirqs); pin++) {
if (pirqs[pin].use_count < best_count) {
best_pin = pin;
best_count = pirqs[pin].use_count;
}
}
}
pirqs[best_pin].use_count++;
/* Second, route this pin to an IRQ. */
if (pirqs[best_pin].reg == PIRQ_DIS) {
best_irq = -1;
best_count = 0;
for (irq = 0; irq < nitems(irq_counts); irq++) {
if (irq_counts[irq] == IRQ_DISABLED)
continue;
if (best_irq == -1 || irq_counts[irq] < best_count) {
best_irq = irq;
best_count = irq_counts[irq];
}
}
assert(best_irq >= 0);
irq_counts[best_irq]++;
pirqs[best_pin].reg = best_irq;
vm_isa_set_irq_trigger(ctx, best_irq, LEVEL_TRIGGER);
}
return (best_pin + 1);
}
int
pirq_irq(int pin)
{
assert(pin > 0 && pin <= nitems(pirqs));
return (pirqs[pin - 1].reg & PIRQ_IRQ);
}
/* XXX: Generate $PIR table. */
static void
pirq_dsdt(void)
{
char *irq_prs, *old;
int irq, pin;
irq_prs = NULL;
for (irq = 0; irq < nitems(irq_counts); irq++) {
if (!IRQ_PERMITTED(irq))
continue;
if (irq_prs == NULL)
asprintf(&irq_prs, "%d", irq);
else {
old = irq_prs;
asprintf(&irq_prs, "%s,%d", old, irq);
free(old);
}
}
/*
* A helper method to validate a link register's value. This
* duplicates pirq_valid_irq().
*/
dsdt_line("");
dsdt_line("Method (PIRV, 1, NotSerialized)");
dsdt_line("{");
dsdt_line(" If (And (Arg0, 0x%02X))", PIRQ_DIS);
dsdt_line(" {");
dsdt_line(" Return (0x00)");
dsdt_line(" }");
dsdt_line(" And (Arg0, 0x%02X, Local0)", PIRQ_IRQ);
dsdt_line(" If (LLess (Local0, 0x03))");
dsdt_line(" {");
dsdt_line(" Return (0x00)");
dsdt_line(" }");
dsdt_line(" If (LEqual (Local0, 0x08))");
dsdt_line(" {");
dsdt_line(" Return (0x00)");
dsdt_line(" }");
dsdt_line(" If (LEqual (Local0, 0x0D))");
dsdt_line(" {");
dsdt_line(" Return (0x00)");
dsdt_line(" }");
dsdt_line(" Return (0x01)");
dsdt_line("}");
for (pin = 0; pin < nitems(pirqs); pin++) {
dsdt_line("");
dsdt_line("Device (LNK%c)", 'A' + pin);
dsdt_line("{");
dsdt_line(" Name (_HID, EisaId (\"PNP0C0F\"))");
dsdt_line(" Name (_UID, 0x%02X)", pin + 1);
dsdt_line(" Method (_STA, 0, NotSerialized)");
dsdt_line(" {");
dsdt_line(" If (PIRV (PIR%c))", 'A' + pin);
dsdt_line(" {");
dsdt_line(" Return (0x0B)");
dsdt_line(" }");
dsdt_line(" Else");
dsdt_line(" {");
dsdt_line(" Return (0x09)");
dsdt_line(" }");
dsdt_line(" }");
dsdt_line(" Name (_PRS, ResourceTemplate ()");
dsdt_line(" {");
dsdt_line(" IRQ (Level, ActiveLow, Shared, )");
dsdt_line(" {%s}", irq_prs);
dsdt_line(" })");
dsdt_line(" Name (CB%02X, ResourceTemplate ()", pin + 1);
dsdt_line(" {");
dsdt_line(" IRQ (Level, ActiveLow, Shared, )");
dsdt_line(" {}");
dsdt_line(" })");
dsdt_line(" CreateWordField (CB%02X, 0x01, CIR%c)",
pin + 1, 'A' + pin);
dsdt_line(" Method (_CRS, 0, NotSerialized)");
dsdt_line(" {");
dsdt_line(" And (PIR%c, 0x%02X, Local0)", 'A' + pin,
PIRQ_DIS | PIRQ_IRQ);
dsdt_line(" If (PIRV (Local0))");
dsdt_line(" {");
dsdt_line(" ShiftLeft (0x01, Local0, CIR%c)", 'A' + pin);
dsdt_line(" }");
dsdt_line(" Else");
dsdt_line(" {");
dsdt_line(" Store (0x00, CIR%c)", 'A' + pin);
dsdt_line(" }");
dsdt_line(" Return (CB%02X)", pin + 1);
dsdt_line(" }");
dsdt_line(" Method (_DIS, 0, NotSerialized)");
dsdt_line(" {");
dsdt_line(" Store (0x80, PIR%c)", 'A' + pin);
dsdt_line(" }");
dsdt_line(" Method (_SRS, 1, NotSerialized)");
dsdt_line(" {");
dsdt_line(" CreateWordField (Arg0, 0x01, SIR%c)", 'A' + pin);
dsdt_line(" FindSetRightBit (SIR%c, Local0)", 'A' + pin);
dsdt_line(" Store (Decrement (Local0), PIR%c)", 'A' + pin);
dsdt_line(" }");
dsdt_line("}");
}
free(irq_prs);
}
LPC_DSDT(pirq_dsdt);