golang 和 C 版本的 pcidumper

pcidumper 主要功能是打印 x86 PCI 配置空间的内容，原来是 C 语言编写，现在用 golang 重写。

#include <stdio.h>
#include <stdlib.h>
#include <sys/io.h>


#define PCI_CONFIG_ADDRESS_PORT    0x0CF8
#define PCI_CONFIG_DATA_PORT    0x0CFC

#define PCI_BUS_MASK        0xFFU
#define PCI_DEV_MASK        0x1FU
#define PCI_FUNC_MASK        0x07U
#define PCI_REG_MASK        0xFCU

#define PCI_BUS_LIMIT        (PCI_BUS_MASK + 1)
#define PCI_DEV_LIMIT        (PCI_DEV_MASK + 1)
#define PCI_FUNC_LIMIT        (PCI_FUNC_MASK + 1)
#define PCI_REG_LIMIT        (PCI_REG_MASK + 4)


static inline void privilege_level(int level)
{
    int rc;

    rc = iopl(level);
    if (rc == -1) {
        perror("iopl");

        exit(EXIT_FAILURE);
    }
}

static inline u_int32_t
x86_io_address(u_int32_t bus, u_int32_t dev, u_int32_t func,
           u_int32_t reg)
{
    u_int32_t address;

    address = (0x80000000U) |
          ((bus & PCI_BUS_MASK) << 16) |
          ((dev & PCI_DEV_MASK) << 11) |
          ((func & PCI_FUNC_MASK) << 8) |
          ((reg & PCI_REG_MASK));

    return address;
}

static u_int32_t
pci_read_conf_reg(u_int32_t bus, u_int32_t dev, u_int32_t func,
          u_int32_t reg)
{
    u_int32_t value;
    u_int32_t address;

    address = x86_io_address(bus, dev, func, reg);

    outl(address, PCI_CONFIG_ADDRESS_PORT);

    value = inl(PCI_CONFIG_DATA_PORT);

    return value;
}

static inline void
pci_dump_header(u_int32_t bus, u_int32_t dev, u_int32_t func)
{
    u_int32_t value;
    u_int32_t offset;

    value = pci_read_conf_reg(bus, dev, func, 0);
    /* check PCI Vendor ID */
    if ((value & 0xFFFFU) == 0xFFFFU) {
        return;
    }

    printf("%d:%d.%d\n00 : 0x%08x ", bus, dev, func, value);

    for (offset = 4; offset < PCI_REG_LIMIT; offset += 4) {
        value = pci_read_conf_reg(bus, dev, func, offset);
        if (((offset & 0x0CU) == 0x0CU)) {
            if (offset != (PCI_BUS_LIMIT - 4)) {
                printf("0x%08x\n%02x : ", value, (offset + 4));
            } else {
                printf("0x%08x\n", value);
            }
        } else {
            printf("0x%08x ", value);
        }
    }
}

int main(int argc, char **argv)
{
    int bus;
    int dev;
    int func;

    /* go to privilege level 3 */
    privilege_level(3);

    /* scan pci buses */
    for (bus = 0; bus < PCI_BUS_LIMIT; bus++) {
        for (dev = 0; dev < PCI_DEV_LIMIT; dev++ ) {
            for (func = 0; func < PCI_FUNC_LIMIT; func++) {
                pci_dump_header(bus, dev, func);
            }
        }
    }

    /* back to privilege level for a normal process */
    privilege_level(0);

    return 0;
}

再看一下 golang 版本的 pcidumper

package main

/*
#include <sys/io.h>
*/
import "C"

import (
    "fmt"
    "os"
    "syscall"
)

const (
    PciAddrPort = 0x0cf8
    PciDataPort = 0x0cfc

    PciBusMask  = 0xff
    PciDevMask  = 0x1f
    PciFuncMask = 0x07
    PciRegMask  = 0xfc

    PciBusLimit  = PciBusMask + 1
    PciDevLimit  = PciDevMask + 1
    PciFuncLimit = PciFuncMask + 1
    PciRegLimit  = PciRegMask + 1
)

func ioLevel(level int) {
    if err := syscall.Iopl(level); err != nil {
        fmt.Print(err)

        os.Exit(1)
    }
}

func pciReadConfReg(bus, dev, function, offset uint32) (value uint32) {

    address := 0x80000000 |
        (bus&PciBusMask)<<16 |
        (dev&PciDevMask)<<11 |
        (function&PciFuncMask)<<8 |
        (offset & PciRegMask)

    C.outl(C.uint(address), PciAddrPort)

    value = uint32(C.inl(PciDataPort))

    return
}

func pciDumpHeader(bus, dev, function uint32) {
    var offset uint32

    /* check PCI Vendor ID */
    value := pciReadConfReg(bus, dev, function, 0)
    if value&0xffff == 0xffff {
        return
    }

    fmt.Printf("%d:%d.%d\n00 : 0x%08x ", bus, dev, function, value)

    for offset = 4; offset < PciRegLimit; offset += 4 {
        value = pciReadConfReg(bus, dev, function, offset)
        if offset&0x0c == 0x0c {
            if offset != (PciBusLimit - 4) {
                fmt.Printf("0x%08x\n%02x : ", value, (offset + 4))
            } else {
                fmt.Printf("0x%08x\n", value)
            }
        } else {
            fmt.Printf("0x%08x ", value)
        }
    }
}

func main() {
    var bus uint32
    var dev uint32
    var function uint32

    ioLevel(3)

    /* scan pci buses */
    for bus = 0; bus < PciBusLimit; bus++ {
        for dev = 0; dev < PciDevLimit; dev++ {
            for function = 0; function < PciFuncLimit; function++ {
                pciDumpHeader(bus, dev, function)
            }
        }
    }

    ioLevel(0)
}

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