Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 142 insertions, 0 deletions

diff --git a/drivers/uio/uio_pci_generic.c b/drivers/uio/uio_pci_generic.c
new file mode 100644
index 000000000..dde5cbb27
--- /dev/null
+++ b/drivers/uio/uio_pci_generic.c
@@ -0,0 +1,142 @@
+// 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 = pci_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)) {
+		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.release = release;
+	gdev->pdev = pdev;
+	if (pdev->irq) {
+		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");
+	}
+
+	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);