mirror of
https://github.com/cirosantilli/linux-kernel-module-cheat.git
synced 2026-01-13 20:12:26 +00:00
92 lines
2.0 KiB
C
92 lines
2.0 KiB
C
/* https://cirosantilli.com/linux-kernel-module-cheat#pci_min */
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#include <linux/cdev.h>
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#include <linux/fs.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/pci.h>
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#include <linux/uaccess.h> /* copy_from_user, copy_to_user */
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#define BAR 0
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#define CDEV_NAME "lkmc_hw_pci_min"
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#define EDU_DEVICE_ID 0x11e9
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#define QEMU_VENDOR_ID 0x1234
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static struct pci_device_id id_table[] = {
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{ PCI_DEVICE(QEMU_VENDOR_ID, EDU_DEVICE_ID), },
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{ 0, }
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};
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MODULE_DEVICE_TABLE(pci, id_table);
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static int major;
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static struct pci_dev *pdev;
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static void __iomem *mmio;
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static struct file_operations fops = {
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.owner = THIS_MODULE,
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};
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static irqreturn_t irq_handler(int irq, void *dev)
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{
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pr_info("irq_handler irq = %d dev = %d\n", irq, *(int *)dev);
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iowrite32(0, mmio + 4);
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return IRQ_HANDLED;
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}
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static int probe(struct pci_dev *dev, const struct pci_device_id *id)
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{
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pr_info("probe\n");
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major = register_chrdev(0, CDEV_NAME, &fops);
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pdev = dev;
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if (pci_enable_device(dev) < 0) {
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dev_err(&(pdev->dev), "pci_enable_device\n");
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goto error;
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}
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if (pci_request_region(dev, BAR, "myregion0")) {
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dev_err(&(pdev->dev), "pci_request_region\n");
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goto error;
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}
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mmio = pci_iomap(pdev, BAR, pci_resource_len(pdev, BAR));
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pr_info("dev->irq = %u\n", dev->irq);
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if (request_irq(dev->irq, irq_handler, IRQF_SHARED, "pci_irq_handler0", &major) < 0) {
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dev_err(&(dev->dev), "request_irq\n");
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goto error;
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}
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iowrite32(0x12345678, mmio);
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return 0;
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error:
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return 1;
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}
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static void remove(struct pci_dev *dev)
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{
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pr_info("remove\n");
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free_irq(dev->irq, &major);
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pci_release_region(dev, BAR);
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unregister_chrdev(major, CDEV_NAME);
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}
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static struct pci_driver pci_driver = {
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.name = CDEV_NAME,
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.id_table = id_table,
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.probe = probe,
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.remove = remove,
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};
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static int myinit(void)
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{
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if (pci_register_driver(&pci_driver) < 0) {
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return 1;
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}
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return 0;
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}
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static void myexit(void)
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{
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pci_unregister_driver(&pci_driver);
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}
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module_init(myinit);
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module_exit(myexit);
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MODULE_LICENSE("GPL");
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