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我正在爲Linux 2.6.36編程一個PCI驅動程序。Linux驅動程序開發：PCI和PCIe驅動程序之間的區別？
這是我的代碼。我的問題是，如果我想將此驅動程序用於PCIe設備，是否必須進行一些修改？
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <asm-generic/signal.h>
#undef debug
// ATTENTION copied from /uboot_for_mpc/arch/powerpc/include/asm/signal.h
// Maybe it don't work with that
//____________________________________________________________
#define SA_INTERRUPT 0x20000000 /* dummy -- ignored */
#define SA_SHIRQ 0x04000000
//____________________________________________________________
#define pci_module_init pci_register_driver // function is obsoleted
// Hardware specific part
#define MY_VENDOR_ID 0x5333
#define MY_DEVICE_ID 0x8e40
#define MAJOR_NR 240
#define DRIVER_NAME "PCI-Driver"
static unsigned long ioport=0L, iolen=0L, memstart=0L, memlen=0L,flag0,flag1,flag2,temp=0L;
// private_data
struct _instance_data {
int counter; // just as a example (5-27)
// other instance specific data
};
// Interrupt Service Routine
static irqreturn_t pci_isr(int irq, void *dev_id, struct pt_regs *regs)
{
return IRQ_HANDLED;
}
// Check if this driver is for the new device
static int device_init(struct pci_dev *dev,
const struct pci_device_id *id)
{
int err=0; // temp variable
#ifdef debug
flag0=pci_resource_flags(dev, 0);
flag1=pci_resource_flags(dev, 1);
flag2=pci_resource_flags(dev, 2);
printk("DEBUG: FLAGS0 = %u\n",flag0);
printk("DEBUG: FLAGS1 = %u\n",flag1);
printk("DEBUG: FLAGS2 = %u\n",flag2);
/*
* The following sequence checks if the resource is in the
* IO/Storage/Interrupt/DMA address space
* and prints the result in the dmesg log
*/
if(pci_resource_flags(dev,0) & IORESOURCE_IO)
{
// Ressource is in the IO address space
printk("DEBUG: IORESOURCE_IO\n");
}
else if (pci_resource_flags(dev,0) & IORESOURCE_MEM)
{
// Resource is in the Storage address space
printk("DEBUG: IORESOURCE_MEM\n");
}
else if (pci_resource_flags(dev,0) & IORESOURCE_IRQ)
{
// Resource is in the IRQ address space
printk("DEBUG: IORESOURCE_IRQ\n");
}
else if (pci_resource_flags(dev,0) & IORESOURCE_DMA)
{
// Resource is in the DMA address space
printk("DEBUG: IORESOURCE_DMA\n");
}
else
{
printk("DEBUG: NOTHING\n");
}
#endif /* debug */
// allocate memory_region
memstart = pci_resource_start(dev, 0);
memlen = pci_resource_len(dev, 0);
if(request_mem_region(memstart, memlen, dev->dev.kobj.name)==NULL) {
printk(KERN_ERR "Memory address conflict for device \"%s\"\n",
dev->dev.kobj.name);
return -EIO;
}
// allocate a interrupt
if(request_irq(dev->irq,pci_isr,SA_INTERRUPT|SA_SHIRQ,
"pci_drv",dev)) {
printk(KERN_ERR "pci_drv: IRQ %d not free.\n", dev->irq);
}
else
{
err=pci_enable_device(dev);
if(err==0) // enable device successful
{
return 0;
}
else // enable device not successful
{
return err;
}
}
// cleanup_mem
release_mem_region(memstart, memlen);
return -EIO;
}
// Function for deinitialization of the device
static void device_deinit(struct pci_dev *pdev)
{
free_irq(pdev->irq, pdev);
if(memstart)
release_mem_region(memstart, memlen);
}
static struct file_operations pci_fops;
static struct pci_device_id pci_drv_tbl[] __devinitdata = {
{ MY_VENDOR_ID, // manufacturer identifier
MY_DEVICE_ID, // device identifier
PCI_ANY_ID, // subsystem manufacturer identifier
PCI_ANY_ID, // subsystem device identifier
0, // device class
0, // mask for device class
0 }, // driver specific data
{ 0, }
};
static int driver_open(struct inode *geraetedatei, struct file *instance)
{
struct _instance_data *iptr;
iptr = (struct _instance_data *)kmalloc(sizeof(struct _instance_data),
GFP_KERNEL);
if(iptr==0) {
printk("not enough kernel mem\n");
return -ENOMEM;
}
/* replace the following line with your instructions */
iptr->counter= strlen("Hello World\n")+1; // just as a example (5-27)
instance->private_data = (void *)iptr;
return 0;
}
static void driver_close(struct file *instance)
{
if(instance->private_data)
kfree(instance->private_data);
}
static struct pci_driver pci_drv = {
.name= "pci_drv",
.id_table= pci_drv_tbl,
.probe= device_init,
.remove= device_deinit,
};
static int __init pci_drv_init(void)
{ // register the driver by the OS
if(register_chrdev(MAJOR_NR, DRIVER_NAME, &pci_fops)==0) {
if(pci_module_init(&pci_drv) == 0) // register by the subsystem
return 0;
unregister_chrdev(MAJOR_NR,DRIVER_NAME); // unregister if no subsystem support
}
return -EIO;
}
static void __exit pci_drv_exit(void)
{
pci_unregister_driver(&pci_drv);
unregister_chrdev(MAJOR_NR,DRIVER_NAME);
}
module_init(pci_drv_init);
module_exit(pci_drv_exit);
MODULE_LICENSE("GPL");
在調用'pci_enable_device'之後調用'release_mem_region'是否合適？就目前而言，即使此通話失敗，內存區仍將被分配。也許使用'check_mem_region'也可能是一種理智的行爲？ – HonkyTonk