toaruos/modules/piix4.c

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/**
* @file modules/piix4.c
* @brief Intel PIIX4 ISA Bridge Driver
*
* @copyright
* This file is part of ToaruOS and is released under the terms
* of the NCSA / University of Illinois License - see LICENSE.md
* Copyright (C) 2021 K. Lange
*/
#include <errno.h>
#include <kernel/types.h>
#include <kernel/args.h>
#include <kernel/printf.h>
#include <kernel/pci.h>
#include <kernel/module.h>
#define PIIX4_PCI_PIRQRC 0x60
static void find_isa_bridge(uint32_t device, uint16_t vendorid, uint16_t deviceid, void * extra) {
if (vendorid == 0x8086 && (deviceid == 0x7000 || deviceid == 0x7110)) {
*((uint32_t *)extra) = device;
}
}
static uint32_t pci_isa = 0;
static int pci_isa_base_slot = 0;
static int pci_isa_bus_offset = 0;
static int pci_isa_last_bus = 0;
static uint8_t pci_remaps[4] = {0};
static void piix_remap(uint32_t device, uint16_t vendorid, uint16_t deviceid, void * extra) {
uint32_t irq_pin = pci_read_field(device, PCI_INTERRUPT_PIN, 1);
uint32_t irq_line = pci_read_field(device, PCI_INTERRUPT_LINE, 1);
if (irq_pin == 0) return;
if (pci_extract_bus(device) != pci_isa_last_bus) {
pci_isa_bus_offset++;
pci_isa_last_bus = pci_extract_bus(device);
}
/* Calculate PIRQ from pin and device slot. */
int slot = (pci_extract_slot(device) - pci_isa_base_slot) % 4;
int bus = (pci_isa_bus_offset) % 4;
int pirq = (slot + irq_pin + bus - 1) % 4;
if (irq_line < 32 && irq_line != pci_remaps[pirq]) {
pci_write_field(device, PCI_INTERRUPT_LINE, 1, pci_remaps[pirq]);
}
}
static int init(int argc, char * argv[]) {
if (args_present("nopciremap")) return -ENODEV;
pci_scan(&find_isa_bridge, -1, &pci_isa);
if (!pci_isa) {
return -ENODEV;
}
pci_isa_base_slot = pci_extract_slot(pci_isa);
pci_isa_last_bus = pci_extract_bus(pci_isa);
for (int i = 0; i < 4; ++i) {
pci_remaps[i] = pci_read_field(pci_isa, PIIX4_PCI_PIRQRC + i, 1);
}
uint32_t out = 0;
memcpy(&out, &pci_remaps, 4);
pci_write_field(pci_isa, PIIX4_PCI_PIRQRC, 4, out);
pci_scan(piix_remap, -1, NULL);
return 0;
}
static int fini(void) {
return 0;
}
struct Module metadata = {
.name = "piix4",
.init = init,
.fini = fini,
};