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149 lines
4.1 KiB
149 lines
4.1 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* uio_pci_generic - generic UIO driver for PCI 2.3 devices |
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* |
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* Copyright (C) 2009 Red Hat, Inc. |
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* Author: Michael S. Tsirkin <[email protected]> |
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* |
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* Since the driver does not declare any device ids, you must allocate |
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* id and bind the device to the driver yourself. For example: |
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* |
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* # echo "8086 10f5" > /sys/bus/pci/drivers/uio_pci_generic/new_id |
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* # echo -n 0000:00:19.0 > /sys/bus/pci/drivers/e1000e/unbind |
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* # echo -n 0000:00:19.0 > /sys/bus/pci/drivers/uio_pci_generic/bind |
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* # ls -l /sys/bus/pci/devices/0000:00:19.0/driver |
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* .../0000:00:19.0/driver -> ../../../bus/pci/drivers/uio_pci_generic |
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* |
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* Driver won't bind to devices which do not support the Interrupt Disable Bit |
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* in the command register. All devices compliant to PCI 2.3 (circa 2002) and |
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* all compliant PCI Express devices should support this bit. |
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*/ |
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#include <linux/device.h> |
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#include <linux/module.h> |
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#include <linux/pci.h> |
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#include <linux/slab.h> |
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#include <linux/uio_driver.h> |
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#define DRIVER_VERSION "0.01.0" |
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#define DRIVER_AUTHOR "Michael S. Tsirkin <[email protected]>" |
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#define DRIVER_DESC "Generic UIO driver for PCI 2.3 devices" |
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struct uio_pci_generic_dev { |
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struct uio_info info; |
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struct pci_dev *pdev; |
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}; |
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static inline struct uio_pci_generic_dev * |
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to_uio_pci_generic_dev(struct uio_info *info) |
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{ |
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return container_of(info, struct uio_pci_generic_dev, info); |
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} |
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static int release(struct uio_info *info, struct inode *inode) |
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{ |
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struct uio_pci_generic_dev *gdev = to_uio_pci_generic_dev(info); |
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/* |
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* This driver is insecure when used with devices doing DMA, but some |
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* people (mis)use it with such devices. |
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* Let's at least make sure DMA isn't left enabled after the userspace |
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* driver closes the fd. |
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* Note that there's a non-zero chance doing this will wedge the device |
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* at least until reset. |
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*/ |
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pci_clear_master(gdev->pdev); |
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return 0; |
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} |
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/* Interrupt handler. Read/modify/write the command register to disable |
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* the interrupt. */ |
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static irqreturn_t irqhandler(int irq, struct uio_info *info) |
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{ |
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struct uio_pci_generic_dev *gdev = to_uio_pci_generic_dev(info); |
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if (!pci_check_and_mask_intx(gdev->pdev)) |
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return IRQ_NONE; |
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/* UIO core will signal the user process. */ |
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return IRQ_HANDLED; |
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} |
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static int probe(struct pci_dev *pdev, |
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const struct pci_device_id *id) |
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{ |
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struct uio_pci_generic_dev *gdev; |
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struct uio_mem *uiomem; |
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int err; |
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int i; |
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err = pcim_enable_device(pdev); |
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if (err) { |
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dev_err(&pdev->dev, "%s: pci_enable_device failed: %d\n", |
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__func__, err); |
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return err; |
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} |
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if (pdev->irq && !pci_intx_mask_supported(pdev)) |
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return -ENODEV; |
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gdev = devm_kzalloc(&pdev->dev, sizeof(struct uio_pci_generic_dev), GFP_KERNEL); |
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if (!gdev) |
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return -ENOMEM; |
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gdev->info.name = "uio_pci_generic"; |
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gdev->info.version = DRIVER_VERSION; |
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gdev->info.release = release; |
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gdev->pdev = pdev; |
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if (pdev->irq && (pdev->irq != IRQ_NOTCONNECTED)) { |
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gdev->info.irq = pdev->irq; |
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gdev->info.irq_flags = IRQF_SHARED; |
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gdev->info.handler = irqhandler; |
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} else { |
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dev_warn(&pdev->dev, "No IRQ assigned to device: " |
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"no support for interrupts?\n"); |
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} |
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uiomem = &gdev->info.mem[0]; |
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for (i = 0; i < MAX_UIO_MAPS; ++i) { |
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struct resource *r = &pdev->resource[i]; |
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if (r->flags != (IORESOURCE_SIZEALIGN | IORESOURCE_MEM)) |
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continue; |
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if (uiomem >= &gdev->info.mem[MAX_UIO_MAPS]) { |
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dev_warn( |
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&pdev->dev, |
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"device has more than " __stringify( |
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MAX_UIO_MAPS) " I/O memory resources.\n"); |
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break; |
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} |
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uiomem->memtype = UIO_MEM_PHYS; |
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uiomem->addr = r->start & PAGE_MASK; |
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uiomem->offs = r->start & ~PAGE_MASK; |
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uiomem->size = |
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(uiomem->offs + resource_size(r) + PAGE_SIZE - 1) & |
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PAGE_MASK; |
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uiomem->name = r->name; |
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++uiomem; |
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} |
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while (uiomem < &gdev->info.mem[MAX_UIO_MAPS]) { |
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uiomem->size = 0; |
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++uiomem; |
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} |
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return devm_uio_register_device(&pdev->dev, &gdev->info); |
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} |
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static struct pci_driver uio_pci_driver = { |
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.name = "uio_pci_generic", |
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.id_table = NULL, /* only dynamic id's */ |
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.probe = probe, |
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}; |
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module_pci_driver(uio_pci_driver); |
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MODULE_VERSION(DRIVER_VERSION); |
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MODULE_LICENSE("GPL v2"); |
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MODULE_AUTHOR(DRIVER_AUTHOR); |
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MODULE_DESCRIPTION(DRIVER_DESC);
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