mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-16 07:24:39 +08:00
61de21a831
Some devices use 255 as default value of Interrupt Line register, and this maybe causes pdev->irq is set as IRQ_NOTCONNECTED in some scenarios. For example, NVMe controller connects to Intel Volume Management Device (VMD). In this situation, IRQ_NOTCONNECTED means INTx line is not connected, not fault. If bind uio_pci_generic to these devices, uio frame will return -ENOTCONN through request_irq. This patch allows binding uio_pci_generic to device with dev->irq of IRQ_NOTCONNECTED. Acked-by: Kyungsan Kim <ks0204.kim@samsung.com> Signed-off-by: Jie Li <jie6.li@samsung.com> Link: https://lore.kernel.org/r/1612153559-17028-1-git-send-email-jie6.li@samsung.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
|
||
/* uio_pci_generic - generic UIO driver for PCI 2.3 devices
|
||
*
|
||
* Copyright (C) 2009 Red Hat, Inc.
|
||
* Author: Michael S. Tsirkin <mst@redhat.com>
|
||
*
|
||
* Since the driver does not declare any device ids, you must allocate
|
||
* id and bind the device to the driver yourself. For example:
|
||
*
|
||
* # echo "8086 10f5" > /sys/bus/pci/drivers/uio_pci_generic/new_id
|
||
* # echo -n 0000:00:19.0 > /sys/bus/pci/drivers/e1000e/unbind
|
||
* # echo -n 0000:00:19.0 > /sys/bus/pci/drivers/uio_pci_generic/bind
|
||
* # ls -l /sys/bus/pci/devices/0000:00:19.0/driver
|
||
* .../0000:00:19.0/driver -> ../../../bus/pci/drivers/uio_pci_generic
|
||
*
|
||
* Driver won't bind to devices which do not support the Interrupt Disable Bit
|
||
* in the command register. All devices compliant to PCI 2.3 (circa 2002) and
|
||
* all compliant PCI Express devices should support this bit.
|
||
*/
|
||
|
||
#include <linux/device.h>
|
||
#include <linux/module.h>
|
||
#include <linux/pci.h>
|
||
#include <linux/slab.h>
|
||
#include <linux/uio_driver.h>
|
||
|
||
#define DRIVER_VERSION "0.01.0"
|
||
#define DRIVER_AUTHOR "Michael S. Tsirkin <mst@redhat.com>"
|
||
#define DRIVER_DESC "Generic UIO driver for PCI 2.3 devices"
|
||
|
||
struct uio_pci_generic_dev {
|
||
struct uio_info info;
|
||
struct pci_dev *pdev;
|
||
};
|
||
|
||
static inline struct uio_pci_generic_dev *
|
||
to_uio_pci_generic_dev(struct uio_info *info)
|
||
{
|
||
return container_of(info, struct uio_pci_generic_dev, info);
|
||
}
|
||
|
||
static int release(struct uio_info *info, struct inode *inode)
|
||
{
|
||
struct uio_pci_generic_dev *gdev = to_uio_pci_generic_dev(info);
|
||
|
||
/*
|
||
* This driver is insecure when used with devices doing DMA, but some
|
||
* people (mis)use it with such devices.
|
||
* Let's at least make sure DMA isn't left enabled after the userspace
|
||
* driver closes the fd.
|
||
* Note that there's a non-zero chance doing this will wedge the device
|
||
* at least until reset.
|
||
*/
|
||
pci_clear_master(gdev->pdev);
|
||
return 0;
|
||
}
|
||
|
||
/* Interrupt handler. Read/modify/write the command register to disable
|
||
* the interrupt. */
|
||
static irqreturn_t irqhandler(int irq, struct uio_info *info)
|
||
{
|
||
struct uio_pci_generic_dev *gdev = to_uio_pci_generic_dev(info);
|
||
|
||
if (!pci_check_and_mask_intx(gdev->pdev))
|
||
return IRQ_NONE;
|
||
|
||
/* UIO core will signal the user process. */
|
||
return IRQ_HANDLED;
|
||
}
|
||
|
||
static int probe(struct pci_dev *pdev,
|
||
const struct pci_device_id *id)
|
||
{
|
||
struct uio_pci_generic_dev *gdev;
|
||
int err;
|
||
|
||
err = pcim_enable_device(pdev);
|
||
if (err) {
|
||
dev_err(&pdev->dev, "%s: pci_enable_device failed: %d\n",
|
||
__func__, err);
|
||
return err;
|
||
}
|
||
|
||
if (pdev->irq && !pci_intx_mask_supported(pdev))
|
||
return -ENOMEM;
|
||
|
||
gdev = devm_kzalloc(&pdev->dev, sizeof(struct uio_pci_generic_dev), GFP_KERNEL);
|
||
if (!gdev)
|
||
return -ENOMEM;
|
||
|
||
gdev->info.name = "uio_pci_generic";
|
||
gdev->info.version = DRIVER_VERSION;
|
||
gdev->info.release = release;
|
||
gdev->pdev = pdev;
|
||
if (pdev->irq && (pdev->irq != IRQ_NOTCONNECTED)) {
|
||
gdev->info.irq = pdev->irq;
|
||
gdev->info.irq_flags = IRQF_SHARED;
|
||
gdev->info.handler = irqhandler;
|
||
} else {
|
||
dev_warn(&pdev->dev, "No IRQ assigned to device: "
|
||
"no support for interrupts?\n");
|
||
}
|
||
|
||
return devm_uio_register_device(&pdev->dev, &gdev->info);
|
||
}
|
||
|
||
static struct pci_driver uio_pci_driver = {
|
||
.name = "uio_pci_generic",
|
||
.id_table = NULL, /* only dynamic id's */
|
||
.probe = probe,
|
||
};
|
||
|
||
module_pci_driver(uio_pci_driver);
|
||
MODULE_VERSION(DRIVER_VERSION);
|
||
MODULE_LICENSE("GPL v2");
|
||
MODULE_AUTHOR(DRIVER_AUTHOR);
|
||
MODULE_DESCRIPTION(DRIVER_DESC);
|