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