forked from Minki/linux
156ed0215e
Commitef84928cff("uio/uio_pci_generic: use device-managed function equivalents") was able to simplify various error paths thanks to no longer having to clean up on the way out. Some error paths were dropped, others were simplified. In one of those simplifications, the return value was accidentally changed from -ENODEV to -ENOMEM. Restore the old return value. Fixes:ef84928cff("uio/uio_pci_generic: use device-managed function equivalents") Cc: stable <stable@vger.kernel.org> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Martin Ågren <martin.agren@gmail.com> Link: https://lore.kernel.org/r/20210422192240.1136373-1-martin.agren@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
118 lines
3.4 KiB
C
118 lines
3.4 KiB
C
// 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 <mst@redhat.com>
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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 <mst@redhat.com>"
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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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int err;
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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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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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