toaruos/kernel/misc/pci.c

133 lines
3.6 KiB
C

/**
* @file kernel/misc/pci.c
* @brief PCI configuration and scanning.
*
* Functions for dealing with PCI devices through configuration mode #1
* (CPU port I/O methods), including scanning and modifying device
* configuration bytes.
*
* This used to have methods for dealing with ISA bridge IRQ remapping,
* but it has been removed for the moment.
*
* TODO: Implement MSI configuration?
*/
#include <stdint.h>
#include <kernel/string.h>
#include <kernel/pci.h>
#include <kernel/printf.h>
/* TODO: PCI is sufficiently generic this shouldn't depend
* directly on x86-64 hardware... */
#include <kernel/arch/x86_64/ports.h>
/**
* @brief Write to a PCI device configuration space field.
*/
void pci_write_field(uint32_t device, int field, int size, uint32_t value) {
outportl(PCI_ADDRESS_PORT, pci_get_addr(device, field));
outportl(PCI_VALUE_PORT, value);
}
/**
* @brief Read from a PCI device configuration space field.
*/
uint32_t pci_read_field(uint32_t device, int field, int size) {
outportl(PCI_ADDRESS_PORT, pci_get_addr(device, field));
if (size == 4) {
uint32_t t = inportl(PCI_VALUE_PORT);
return t;
} else if (size == 2) {
uint16_t t = inports(PCI_VALUE_PORT + (field & 2));
return t;
} else if (size == 1) {
uint8_t t = inportb(PCI_VALUE_PORT + (field & 3));
return t;
}
return 0xFFFF;
}
/**
* @brief Obtain the device type from the class and subclass fields.
*/
uint16_t pci_find_type(uint32_t dev) {
return (pci_read_field(dev, PCI_CLASS, 1) << 8) | pci_read_field(dev, PCI_SUBCLASS, 1);
}
static void pci_scan_hit(pci_func_t f, uint32_t dev, void * extra) {
int dev_vend = (int)pci_read_field(dev, PCI_VENDOR_ID, 2);
int dev_dvid = (int)pci_read_field(dev, PCI_DEVICE_ID, 2);
f(dev, dev_vend, dev_dvid, extra);
}
void pci_scan_func(pci_func_t f, int type, int bus, int slot, int func, void * extra) {
uint32_t dev = pci_box_device(bus, slot, func);
if (type == -1 || type == pci_find_type(dev)) {
pci_scan_hit(f, dev, extra);
}
if (pci_find_type(dev) == PCI_TYPE_BRIDGE) {
pci_scan_bus(f, type, pci_read_field(dev, PCI_SECONDARY_BUS, 1), extra);
}
}
void pci_scan_slot(pci_func_t f, int type, int bus, int slot, void * extra) {
uint32_t dev = pci_box_device(bus, slot, 0);
if (pci_read_field(dev, PCI_VENDOR_ID, 2) == PCI_NONE) {
return;
}
pci_scan_func(f, type, bus, slot, 0, extra);
if (!pci_read_field(dev, PCI_HEADER_TYPE, 1)) {
return;
}
for (int func = 1; func < 8; func++) {
uint32_t dev = pci_box_device(bus, slot, func);
if (pci_read_field(dev, PCI_VENDOR_ID, 2) != PCI_NONE) {
pci_scan_func(f, type, bus, slot, func, extra);
}
}
}
void pci_scan_bus(pci_func_t f, int type, int bus, void * extra) {
for (int slot = 0; slot < 32; ++slot) {
pci_scan_slot(f, type, bus, slot, extra);
}
}
/**
* @brief Scan PCI buses for devices, calling the given function for each device.
*
* Used by drivers to implement device discovery, runs a callback function for ever
* device found. A device consists of a bus, slot, and function. Also performs
* recursive scans of bridges.
*/
void pci_scan(pci_func_t f, int type, void * extra) {
if ((pci_read_field(0, PCI_HEADER_TYPE, 1) & 0x80) == 0) {
pci_scan_bus(f,type,0,extra);
return;
}
int hit = 0;
for (int func = 0; func < 8; ++func) {
uint32_t dev = pci_box_device(0, 0, func);
if (pci_read_field(dev, PCI_VENDOR_ID, 2) != PCI_NONE) {
hit = 1;
pci_scan_bus(f, type, func, extra);
} else {
break;
}
}
if (!hit) {
for (int bus = 0; bus < 256; ++bus) {
for (int slot = 0; slot < 32; ++slot) {
pci_scan_slot(f,type,bus,slot,extra);
}
}
}
}
int pci_get_interrupt(uint32_t device) {
return pci_read_field(device, PCI_INTERRUPT_LINE, 1);
}