virt_plat_dev: Register the virt platform device driver (e4c0f182) · Commits · EulixOS / Software / Kernel

drivers/misc/Kconfig

+9 −0

Original line number	Diff line number	Diff line
		@@ -474,6 +474,15 @@ config HISI_HIKEY_USB
		switching between the dual-role USB-C port and the USB-A host ports
		using only one USB controller.

		config VIRT_PLAT_DEV
		depends on KVM && ARM64 && ARCH_HISI
		default y
		tristate "virt platform device driver"
		help
		Enable this configuration option to probe the virtual platform device,
		which created for the Qemu emulated device to implement virtual MSI
		direct injection.

		source "drivers/misc/c2port/Kconfig"
		source "drivers/misc/eeprom/Kconfig"
		source "drivers/misc/cb710/Kconfig"

drivers/misc/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -58,3 +58,4 @@ obj-$(CONFIG_HABANA_AI) += habanalabs/
		obj-$(CONFIG_UACCE) += uacce/
		obj-$(CONFIG_XILINX_SDFEC) += xilinx_sdfec.o
		obj-$(CONFIG_HISI_HIKEY_USB) += hisi_hikey_usb.o
		obj-$(CONFIG_VIRT_PLAT_DEV) += virt_plat_dev.o

drivers/misc/virt_plat_dev.c

0 → 100644

+119 −0

Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0-only
		/*
		* Copyright (C) 2019-2020 HUAWEI TECHNOLOGIES CO., LTD., All Rights Reserved.
		* Author: Wanghaibin <wanghaibin.wang@huawei.com>
		*/
		#include <linux/err.h>
		#include <linux/interrupt.h>
		#include <linux/irq.h>
		#include <linux/module.h>
		#include <linux/msi.h>
		#include <linux/platform_device.h>
		#include <linux/uaccess.h>
		#include <linux/device.h>

		#define VIRT_DEV_DEBUG 1

		#ifdef VIRT_DEV_DEBUG
		#define virtdev_info(fmt, ...) pr_info("virdev: " fmt, ## __VA_ARGS__)
		#else
		#define virtdev_info(fmt, ...)
		#endif

		static irqreturn_t virt_irq_handle(int irq, void *data)
		{
		return IRQ_HANDLED;
		}

		static void virt_write_msi_msg(struct msi_desc desc, struct msi_msg msg)
		{
		}

		static int virt_device_probe(struct platform_device *pdev)
		{
		struct msi_desc *desc;
		unsigned int *drvdata = dev_get_drvdata(&pdev->dev);
		unsigned int nvec = *drvdata;
		struct irq_domain *vp_irqdomain = vp_get_irq_domain();
		int ret;

		if (!vp_irqdomain)
		return -ENXIO;

		virtdev_info("Allocate platform msi irqs nvecs: %d\n", nvec);
		dev_set_msi_domain(&pdev->dev, vp_irqdomain);

		ret = platform_msi_domain_alloc_irqs(&pdev->dev, nvec,
		virt_write_msi_msg);
		if (ret) {
		pr_err("Allocate platform msi irqs failed %d\n", ret);
		goto error;
		}

		virtdev_info("Allocate platform msi irqs succeed\n");
		for_each_msi_entry(desc, &pdev->dev) {
		virtdev_info("Request irq %d\n", desc->irq);
		ret = request_irq(desc->irq, virt_irq_handle, 0,
		"virt_dev_host", pdev);
		if (ret) {
		pr_err("Request irq %d failed %d\n", desc->irq, ret);
		goto error_free_irqs;
		}
		}

		virtdev_info("Init virtual platform device driver successfully.\n");
		return 0;

		error_free_irqs:
		for_each_msi_entry(desc, &pdev->dev)
		free_irq(desc->irq, pdev);

		platform_msi_domain_free_irqs(&pdev->dev);
		error:
		return ret;
		}

		static int virt_device_remove(struct platform_device *pdev)
		{
		struct msi_desc *desc;

		virtdev_info("%s\n", __func__);
		for_each_msi_entry(desc, &pdev->dev)
		free_irq(desc->irq, pdev);

		platform_msi_domain_free_irqs(&pdev->dev);

		return 0;
		}

		static struct platform_driver virtdev_driver = {
		.driver = {
		/* Using the device & driver name to match each other */
		.name = "virt_plat_dev",
		},
		.probe = virt_device_probe,
		.remove = virt_device_remove,
		};

		static int __init virtdev_init(void)
		{
		int ret;

		ret = platform_driver_register(&virtdev_driver);
		if (ret) {
		pr_err("Register virtdev platform driver failed (%d)\n", ret);
		return ret;
		}

		virtdev_info("Register virtdev platform driver succeed.\n");
		return 0;
		}
		module_init(virtdev_init);

		static void __exit virtdev_exit(void)
		{
		platform_driver_unregister(&virtdev_driver);
		}
		module_exit(virtdev_exit);

		MODULE_LICENSE("GPL v2");