Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / uio / uio_pci_generic.c

diff --git a/kernel/drivers/uio/uio_pci_generic.c b/kernel/drivers/uio/uio_pci_generic.c
new file mode 100644 (file)
index 0000000..d0b508b
--- /dev/null
+++ b/kernel/drivers/uio/uio_pci_generic.c
@@ -0,0 +1,128 @@
+/* uio_pci_generic - generic UIO driver for PCI 2.3 devices
+ *
+ * Copyright (C) 2009 Red Hat, Inc.
+ * Author: Michael S. Tsirkin <mst@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ *
+ * 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);
+}
+
+/* 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 = pci_enable_device(pdev);
+       if (err) {
+               dev_err(&pdev->dev, "%s: pci_enable_device failed: %d\n",
+                       __func__, err);
+               return err;
+       }
+
+       if (!pdev->irq) {
+               dev_warn(&pdev->dev, "No IRQ assigned to device: "
+                        "no support for interrupts?\n");
+               pci_disable_device(pdev);
+               return -ENODEV;
+       }
+
+       if (!pci_intx_mask_supported(pdev)) {
+               err = -ENODEV;
+               goto err_verify;
+       }
+
+       gdev = kzalloc(sizeof(struct uio_pci_generic_dev), GFP_KERNEL);
+       if (!gdev) {
+               err = -ENOMEM;
+               goto err_alloc;
+       }
+
+       gdev->info.name = "uio_pci_generic";
+       gdev->info.version = DRIVER_VERSION;
+       gdev->info.irq = pdev->irq;
+       gdev->info.irq_flags = IRQF_SHARED;
+       gdev->info.handler = irqhandler;
+       gdev->pdev = pdev;
+
+       err = uio_register_device(&pdev->dev, &gdev->info);
+       if (err)
+               goto err_register;
+       pci_set_drvdata(pdev, gdev);
+
+       return 0;
+err_register:
+       kfree(gdev);
+err_alloc:
+err_verify:
+       pci_disable_device(pdev);
+       return err;
+}
+
+static void remove(struct pci_dev *pdev)
+{
+       struct uio_pci_generic_dev *gdev = pci_get_drvdata(pdev);
+
+       uio_unregister_device(&gdev->info);
+       pci_disable_device(pdev);
+       kfree(gdev);
+}
+
+static struct pci_driver uio_pci_driver = {
+       .name = "uio_pci_generic",
+       .id_table = NULL, /* only dynamic id's */
+       .probe = probe,
+       .remove = remove,
+};
+
+module_pci_driver(uio_pci_driver);
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);