On Mon, Dec 09, 2019 at 02:49:16PM -0800, Jeff Kirsher wrote:
> From: Dave Ertman <david.m.ertman@xxxxxxxxx>
>
> This is the initial implementation of the virtual bus,
> virtbus_device and virtbus_driver. The virtual bus is
> a software based bus intended to support registering
> virtbus_devices and virtbus_drivers and provide matching
> between them and probing of the registered drivers.
>
> The primary purpose of the virtual bus is to provide
> matching services to allow the use of a container_of
> to get access to a piece of desired data. This will
> allow two separate kernel objects to match up and
> start communication.
What? That's not the job of a virtual bus, a virtual bus is there to
put devices on it and hook them up to drivers.
What do you mean by "two separate kernel objects"? What are the objects
here?
>
> The bus will support probe/remove shutdown and
> suspend/resume callbacks.
>
> Kconfig and Makefile alterations are included
>
> Signed-off-by: Dave Ertman <david.m.ertman@xxxxxxxxx>
> Signed-off-by: Kiran Patil <kiran.patil@xxxxxxxxx>
> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@xxxxxxxxx>
> ---
> Documentation/driver-api/virtual_bus.rst | 76 +++++
> drivers/bus/Kconfig | 12 +
> drivers/bus/Makefile | 1 +
> drivers/bus/virtual_bus.c | 295 ++++++++++++++++++
> include/linux/mod_devicetable.h | 8 +
> include/linux/virtual_bus.h | 45 +++
> scripts/mod/devicetable-offsets.c | 3 +
> scripts/mod/file2alias.c | 8 +
> .../virtual_bus/virtual_bus_dev/Makefile | 7 +
> .../virtual_bus_dev/virtual_bus_dev.c | 60 ++++
> .../virtual_bus/virtual_bus_drv/Makefile | 7 +
> .../virtual_bus_drv/virtual_bus_drv.c | 115 +++++++
> 12 files changed, 637 insertions(+)
> create mode 100644 Documentation/driver-api/virtual_bus.rst
> create mode 100644 drivers/bus/virtual_bus.c
> create mode 100644 include/linux/virtual_bus.h
> create mode 100644 tools/testing/selftests/virtual_bus/virtual_bus_dev/Makefile
> create mode 100644 tools/testing/selftests/virtual_bus/virtual_bus_dev/virtual_bus_dev.c
> create mode 100644 tools/testing/selftests/virtual_bus/virtual_bus_drv/Makefile
> create mode 100644 tools/testing/selftests/virtual_bus/virtual_bus_drv/virtual_bus_drv.c
>
> diff --git a/Documentation/driver-api/virtual_bus.rst b/Documentation/driver-api/virtual_bus.rst
> new file mode 100644
> index 000000000000..db8c34fcafe8
> --- /dev/null
> +++ b/Documentation/driver-api/virtual_bus.rst
> @@ -0,0 +1,76 @@
> +===============================
> +Virtual Bus Devices and Drivers
> +===============================
> +
> +See <linux/virtual_bus.h> for the models for virtbus_device and virtbus_driver.
> +This bus is meant to be a lightweight software based bus to attach generic
> +devices and drivers to so that a chunk of data can be passed between them.
> +
> +One use case example is an rdma driver needing to connect with several
> +different types of PCI LAN devices to be able to request resources from
> +them (queue sets). Each LAN driver that supports rdma will register a
> +virtbus_device on the virtual bus for each physical function. The rdma
> +driver will register as a virtbus_driver on the virtual bus to be
> +matched up with multiple virtbus_devices and receive a pointer to a
> +struct containing the callbacks that the PCI LAN drivers support for
> +registering with them.
> +
> +Sections in this document:
> + Virtbus devices
> + Virtbus drivers
> + Device Enumeration
> + Device naming and driver binding
> + Virtual Bus API entry points
> +
> +Virtbus devices
> +~~~~~~~~~~~~~~~
> +Virtbus_devices are lightweight objects that support the minimal device
> +functionality. Devices will accept a name, and then an automatically
> +generated index is concatenated onto it for the virtbus_device->name.
> +
> +The virtbus_driver and virtbus_device creators need to both have access
> +to a predefined virtbus_device_object struct that will look like the
> +following:
> + struct virtbus_object {
> + struct virtbus_device vdev;
> + struct foo_type foo;
> + }
> +
> +Then when the virtbus_driver's probe is called with the virtbus_device
> +as a parameter, it can do a container_of on the virtbus_device to get
> +to the struct foo_type foo that it cares about.
That's just how the driver model works, I'm not quite sure what you are
trying to say here. What is this section for?
> +Virtbus drivers
> +~~~~~~~~~~~~~~~
> +Virtbus drivers register with the virtual bus to be matched with virtbus
> +devices. They expect to be registered with a probe and remove callback,
> +and also support shutdown, suspend, and resume callbacks. They otherwise
> +follow the standard driver behavior of having discovery and enumeration
> +handled in the bus infrastructure.
> +
> +Virtbus drivers register themselves with the API entry point virtbus_drv_reg
> +and unregister with virtbus_drv_unreg.
> +
> +Device Enumeration
> +~~~~~~~~~~~~~~~~~~
> +Enumeration is handled automatically by the bus infrastructure via the
> +ida_simple methods.
> +
> +Device naming and driver binding
> +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> +The virtbus_device.dev.name is the canonical name for the device. It is
> +built from two other parts:
> +
> + - virtbus_device.name (also used for matching).
> + - virtbus_device.id (generated automatically from ida_simple calls)
> +
> +This allows for multiple virtbus_devices with the same name, which will all
> +be matched to the same virtbus_driver. Driver binding is performed by the
> +driver core, invoking driver probe() after finding a match between device and driver.
> +
> +Virtual Bus API entry points
> +~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> +int virtbus_dev_register(struct virtbus_device *vdev)
> +void virtbus_dev_unregister(struct virtbus_device *vdev)
> +int virtbus_drv_register(struct virtbus_driver *vdrv, struct module *owner)
> +void virtbus_drv_unregister(struct virtbus_driver *vdrv)
I don't understand this documentation at all. Can't you put what you
need in the code itself and have it be auto-generated? This is really
vague stuff that I can't find useful. And if I don't understand it,
well... :)
> diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
> index 50200d1c06ea..770519d16d43 100644
> --- a/drivers/bus/Kconfig
> +++ b/drivers/bus/Kconfig
> @@ -203,4 +203,16 @@ config DA8XX_MSTPRI
>
> source "drivers/bus/fsl-mc/Kconfig"
>
> +config VIRTUAL_BUS
> + tristate "lightweight Virtual Bus"
Why "lightweight"? Where's the heavy one? :)
> + depends on PM
Why does it depend on PM?
> + help
> + Provides a software bus for virtbus_devices to be added to it
> + and virtbus_drivers to be registered on it. Will create a match
> + between the driver and device, then call the driver's probe with
> + the virtbus_device's struct.
> + One example is the irdma driver needing to connect with various
> + PCI LAN drivers to request resources (queues) to be able to perform
> + its function.
> +
> endmenu
> diff --git a/drivers/bus/Makefile b/drivers/bus/Makefile
> index 1320bcf9fa9d..6721c77dc71b 100644
> --- a/drivers/bus/Makefile
> +++ b/drivers/bus/Makefile
> @@ -34,3 +34,4 @@ obj-$(CONFIG_UNIPHIER_SYSTEM_BUS) += uniphier-system-bus.o
> obj-$(CONFIG_VEXPRESS_CONFIG) += vexpress-config.o
>
> obj-$(CONFIG_DA8XX_MSTPRI) += da8xx-mstpri.o
> +obj-$(CONFIG_VIRTUAL_BUS) += virtual_bus.o
> diff --git a/drivers/bus/virtual_bus.c b/drivers/bus/virtual_bus.c
> new file mode 100644
> index 000000000000..6bc986659e4b
> --- /dev/null
> +++ b/drivers/bus/virtual_bus.c
> @@ -0,0 +1,295 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * virtual_bus.c - lightweight software based bus for virtual devices
> + *
> + * Copyright (c) 2019-20 Intel Corporation
> + *
> + * Please see Documentation/driver-api/virtual_bus.rst for
> + * more information
> + */
> +
> +#include <linux/string.h>
> +#include <linux/virtual_bus.h>
> +#include <linux/of_irq.h>
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/pm_domain.h>
> +#include <linux/acpi.h>
> +#include <linux/device.h>
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("Lightweight Virtual Bus");
> +MODULE_AUTHOR("David Ertman <david.m.ertman@xxxxxxxxx>");
> +MODULE_AUTHOR("Kiran Patil <kiran.patil@xxxxxxxxx>");
> +
> +static DEFINE_IDA(virtbus_dev_ida);
> +
> +static const
> +struct virtbus_dev_id *virtbus_match_id(const struct virtbus_dev_id *id,
> + struct virtbus_device *vdev)
> +{
> + while (id->name[0]) {
> + if (!strcmp(vdev->name, id->name)) {
> + vdev->matched_element = id;
> + return id;
> + }
> + id++;
> + }
> + return NULL;
> +}
> +
> +#define to_virtbus_dev(x) (container_of((x), struct virtbus_device, dev))
> +#define to_virtbus_drv(x) (container_of((x), struct virtbus_driver, \
> + driver))
> +
> +/**
> + * virtbus_match - bind virtbus device to virtbus driver
> + * @dev: device
> + * @drv: driver
> + *
> + * Virtbus device IDs are always in "<name>.<instance>" format.
> + * Instances are automatically selected through an ida_simple_get so
> + * are positive integers. Names are taken from the device name field.
> + * Driver IDs are simple <name>. Need to extract the name from the
> + * Virtual Device compare to name of the driver.
Why kerneldoc for static functions?
This naming scheme is great to have documented somewhere, why am I just
finding it here? See, your .rst file was useless :(
Make the documentation be generated from this .c file please.
> + */
> +static int virtbus_match(struct device *dev, struct device_driver *drv)
> +{
> + struct virtbus_driver *vdrv = to_virtbus_drv(drv);
> + struct virtbus_device *vdev = to_virtbus_dev(dev);
> +
> + if (vdrv->id_table)
> + return virtbus_match_id(vdrv->id_table, vdev) != NULL;
> +
> + return !strcmp(vdev->name, drv->name);
Wait, why would a driver not have an id table? You are matching two
different ways here, only one documented above?
> +}
> +
> +/**
> + * virtbus_probe - call probe of the virtbus_drv
> + * @dev: device struct
> + */
> +static int virtbus_probe(struct device *dev)
> +{
> + if (dev->driver->probe)
> + return dev->driver->probe(dev);
How can we not have a probe? Test for that at registration.
> +
> + return 0;
> +}
> +
> +static int virtbus_remove(struct device *dev)
> +{
> + if (dev->driver->remove)
> + return dev->driver->remove(dev);
Same as above.
> +
> + return 0;
> +}
> +
> +static void virtbus_shutdown(struct device *dev)
> +{
> + if (dev->driver->shutdown)
> + dev->driver->shutdown(dev);
Same as above
> +}
> +
> +static int virtbus_suspend(struct device *dev, pm_message_t state)
> +{
> + if (dev->driver->suspend)
> + return dev->driver->suspend(dev, state);
> +
> + return 0;
> +}
> +
> +static int virtbus_resume(struct device *dev)
> +{
> + if (dev->driver->resume)
> + return dev->driver->resume(dev);
> +
> + return 0;
> +}
> +
> +struct bus_type virtual_bus_type = {
> + .name = "virtbus",
> + .match = virtbus_match,
> + .probe = virtbus_probe,
> + .remove = virtbus_remove,
> + .shutdown = virtbus_shutdown,
> + .suspend = virtbus_suspend,
> + .resume = virtbus_resume,
> +};
> +
> +/**
> + * virtbus_dev_register - add a virtual bus device
> + * @vdev: virtual bus device to add
> + */
> +int virtbus_dev_register(struct virtbus_device *vdev)
> +{
> + int ret;
> +
> + device_initialize(&vdev->dev);
> +
> + vdev->dev.bus = &virtual_bus_type;
> + /* All device IDs are automatically allocated */
> + ret = ida_simple_get(&virtbus_dev_ida, 0, 0, GFP_KERNEL);
> + if (ret < 0)
> + return ret;
Ugh, you just lost the reference count logic for your call to
device_initialize() above, right? Or did you document the heck out of
this saying that if you call virtbus_dev_register, you MUST call
put_device() to properly clean things up.
Nope, you did not :(
> +
> + vdev->id = ret;
> + dev_set_name(&vdev->dev, "%s.%d", vdev->name, vdev->id);
> +
> + dev_dbg(&vdev->dev, "Registering virtbus device '%s'\n",
> + dev_name(&vdev->dev));
> +
> + ret = device_add(&vdev->dev);
> + if (ret)
> + goto device_add_err;
> +
> + return 0;
> +
> +device_add_err:
> + /* Error adding virtual device */
We know that, document things that are not obvious :)
> + put_device(&vdev->dev);
> + ida_simple_remove(&virtbus_dev_ida, vdev->id);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(virtbus_dev_register);
> +
> +/**
> + * virtbus_dev_unregister - remove a virtual bus device
> + * vdev: virtual bus device we are removing
> + */
> +void virtbus_dev_unregister(struct virtbus_device *vdev)
> +{
> + put_device(&vdev->dev);
> +}
> +EXPORT_SYMBOL_GPL(virtbus_dev_unregister);
> +
> +struct virtbus_object {
> + struct virtbus_device vdev;
> + char name[];
Why an empty array? are you sure?
> +};
> +
> +/**
> + * virtbus_dev_release - Destroy a virtbus device
> + * @vdev: virtual device to release
> + *
> + * Note that the vdev->data which is separately allocated needs to be
> + * separately freed on it own.
> + */
> +static void virtbus_dev_release(struct device *dev)
> +{
> + struct virtbus_object *vo = container_of(dev, struct virtbus_object,
> + vdev.dev);
> +
> + ida_simple_remove(&virtbus_dev_ida, vo->vdev.id);
> + kfree(vo);
> +}
> +
> +static int virtbus_drv_probe(struct device *_dev)
> +{
> + struct virtbus_driver *vdrv = to_virtbus_drv(_dev->driver);
> + struct virtbus_device *vdev = to_virtbus_dev(_dev);
> + int ret;
> +
> + ret = dev_pm_domain_attach(_dev, true);
> + if (ret) {
> + dev_warn(_dev, "Failed to attatch to PM Domain : %d\n", ret);
> + return ret;
> + }
> +
> + if (vdrv->probe) {
> + ret = vdrv->probe(vdev);
> + if (ret)
> + dev_pm_domain_detach(_dev, true);
> + }
> +
> + return ret;
> +}
> +
> +static int virtbus_drv_remove(struct device *_dev)
> +{
> + struct virtbus_driver *vdrv = to_virtbus_drv(_dev->driver);
> + struct virtbus_device *vdev = to_virtbus_dev(_dev);
> + int ret = 0;
> +
> + if (vdrv->remove)
> + ret = vdrv->remove(vdev);
> +
> + dev_pm_domain_detach(_dev, true);
> +
> + return ret;
> +}
> +
> +static void virtbus_drv_shutdown(struct device *_dev)
> +{
> + struct virtbus_driver *vdrv = to_virtbus_drv(_dev->driver);
> + struct virtbus_device *vdev = to_virtbus_dev(_dev);
> +
> + if (vdrv->shutdown)
> + vdrv->shutdown(vdev);
> +}
> +
> +static int virtbus_drv_suspend(struct device *_dev, pm_message_t state)
> +{
> + struct virtbus_driver *vdrv = to_virtbus_drv(_dev->driver);
> + struct virtbus_device *vdev = to_virtbus_dev(_dev);
> +
> + if (vdrv->suspend)
> + return vdrv->suspend(vdev, state);
> +
> + return 0;
> +}
> +
> +static int virtbus_drv_resume(struct device *_dev)
> +{
> + struct virtbus_driver *vdrv = to_virtbus_drv(_dev->driver);
> + struct virtbus_device *vdev = to_virtbus_dev(_dev);
> +
> + if (vdrv->resume)
> + return vdrv->resume(vdev);
> +
> + return 0;
> +}
> +
> +/**
> + * __virtbus_drv_register - register a driver for virtual bus devices
> + * @vdrv: virtbus_driver structure
> + * @owner: owning module/driver
> + */
> +int __virtbus_drv_register(struct virtbus_driver *vdrv, struct module *owner)
> +{
> + vdrv->driver.owner = owner;
> + vdrv->driver.bus = &virtual_bus_type;
> + vdrv->driver.probe = virtbus_drv_probe;
> + vdrv->driver.remove = virtbus_drv_remove;
> + vdrv->driver.shutdown = virtbus_drv_shutdown;
> + vdrv->driver.suspend = virtbus_drv_suspend;
> + vdrv->driver.resume = virtbus_drv_resume;
> +
> + return driver_register(&vdrv->driver);
> +}
> +EXPORT_SYMBOL_GPL(__virtbus_drv_register);
> +
> +/**
> + * virtbus_drv_unregister - unregister a driver for virtual bus devices
> + * @drv: virtbus_driver structure
> + */
> +void virtbus_drv_unregister(struct virtbus_driver *vdrv)
> +{
> + driver_unregister(&vdrv->driver);
> +}
> +EXPORT_SYMBOL_GPL(virtbus_drv_unregister);
> +
> +static int __init virtual_bus_init(void)
> +{
> + return bus_register(&virtual_bus_type);
> +}
> +
> +static void __exit virtual_bus_exit(void)
> +{
> + bus_unregister(&virtual_bus_type);
> + ida_destroy(&virtbus_dev_ida);
> +}
> +
> +module_init(virtual_bus_init);
> +module_exit(virtual_bus_exit);
> diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
> index 5714fd35a83c..e19214f84c98 100644
> --- a/include/linux/mod_devicetable.h
> +++ b/include/linux/mod_devicetable.h
> @@ -821,4 +821,12 @@ struct wmi_device_id {
> const void *context;
> };
>
> +#define VIRTBUS_NAME_SIZE 20
> +#define VIRTBUS_MODULE_PREFIX "virtbus:"
> +
> +struct virtbus_dev_id {
> + char name[VIRTBUS_NAME_SIZE];
> + kernel_ulong_t driver_data;
> +};
> +
> #endif /* LINUX_MOD_DEVICETABLE_H */
> diff --git a/include/linux/virtual_bus.h b/include/linux/virtual_bus.h
> new file mode 100644
> index 000000000000..fe4725b1e6b1
> --- /dev/null
> +++ b/include/linux/virtual_bus.h
> @@ -0,0 +1,45 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * virtual_bus.h - lightweight software bus
> + *
> + * Copyright (c) 2019-20 Intel Corporation
> + *
> + * Please see Documentation/driver-api/virtual_bus.rst for more information
> + */
> +
> +#ifndef _VIRTUAL_BUS_H_
> +#define _VIRTUAL_BUS_H_
> +
> +#include <linux/device.h>
> +
> +struct virtbus_device {
> + const char *name;
> + int id;
> + const struct virtbus_dev_id *matched_element;
> + struct device dev;
Put dev at the front might align things a bit better in memory. Not a
big issue...
> +};
> +
> +/* If the driver uses a id_table to match with virtbus_devices, then the
> + * memory for the table is expected to remain allocated for the duration
> + * of the pairing between driver and device. The pointer for the matching
> + * element will be copied to the dev_id field of the virtbus_device.
Again, id_table is optional? Huh????
> + */
> +struct virtbus_driver {
> + int (*probe)(struct virtbus_device *);
> + int (*remove)(struct virtbus_device *);
> + void (*shutdown)(struct virtbus_device *);
> + int (*suspend)(struct virtbus_device *, pm_message_t);
> + int (*resume)(struct virtbus_device *);
> + struct device_driver driver;
> + const struct virtbus_dev_id *id_table;
> +};
> +
> +int virtbus_dev_register(struct virtbus_device *vdev);
> +void virtbus_dev_unregister(struct virtbus_device *vdev);
> +int __virtbus_drv_register(struct virtbus_driver *vdrv, struct module *owner);
> +void virtbus_drv_unregister(struct virtbus_driver *vdrv);
> +
> +#define virtbus_drv_register(vdrv) \
> + __virtbus_drv_register(vdrv, THIS_MODULE)
> +
> +#endif /* _VIRTUAL_BUS_H_ */
> diff --git a/scripts/mod/devicetable-offsets.c b/scripts/mod/devicetable-offsets.c
> index 054405b90ba4..9a6099bf90c8 100644
> --- a/scripts/mod/devicetable-offsets.c
> +++ b/scripts/mod/devicetable-offsets.c
> @@ -231,5 +231,8 @@ int main(void)
> DEVID(wmi_device_id);
> DEVID_FIELD(wmi_device_id, guid_string);
>
> + DEVID(virtbus_dev_id);
> + DEVID_FIELD(virtbus_dev_id, name);
> +
> return 0;
> }
> diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c
> index c91eba751804..713fdfe010b0 100644
> --- a/scripts/mod/file2alias.c
> +++ b/scripts/mod/file2alias.c
> @@ -1335,6 +1335,13 @@ static int do_wmi_entry(const char *filename, void *symval, char *alias)
> return 1;
> }
>
> +static int do_virtbus_entry(const char *filename, void *symval, char *alias)
> +{
> + DEF_FIELD_ADDR(symval, virtbus_dev_id, name);
> + sprintf(alias, VIRTBUS_MODULE_PREFIX "%s", *name);
> + return 1;
> +}
> +
> /* Does namelen bytes of name exactly match the symbol? */
> static bool sym_is(const char *name, unsigned namelen, const char *symbol)
> {
> @@ -1407,6 +1414,7 @@ static const struct devtable devtable[] = {
> {"typec", SIZE_typec_device_id, do_typec_entry},
> {"tee", SIZE_tee_client_device_id, do_tee_entry},
> {"wmi", SIZE_wmi_device_id, do_wmi_entry},
> + {"virtbus", SIZE_virtbus_dev_id, do_virtbus_entry},
> };
>
> /* Create MODULE_ALIAS() statements.
> diff --git a/tools/testing/selftests/virtual_bus/virtual_bus_dev/Makefile b/tools/testing/selftests/virtual_bus/virtual_bus_dev/Makefile
> new file mode 100644
> index 000000000000..ddd5088eb26b
> --- /dev/null
> +++ b/tools/testing/selftests/virtual_bus/virtual_bus_dev/Makefile
> @@ -0,0 +1,7 @@
> +obj-m += virtual_bus_dev.o
> +
> +all:
> + make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
> +
> +clean:
> + make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean
> diff --git a/tools/testing/selftests/virtual_bus/virtual_bus_dev/virtual_bus_dev.c b/tools/testing/selftests/virtual_bus/virtual_bus_dev/virtual_bus_dev.c
> new file mode 100644
> index 000000000000..966e882452d2
> --- /dev/null
> +++ b/tools/testing/selftests/virtual_bus/virtual_bus_dev/virtual_bus_dev.c
> @@ -0,0 +1,60 @@
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/module.h>
> +#include <linux/virtual_bus.h>
> +#include <linux/string.h>
> +#include <linux/slab.h>
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_AUTHOR("Dave Ertman");
> +MODULE_DESCRIPTION("Test to create a device on virtual bus");
> +MODULE_VERSION("1.0");
> +
> +struct virtbus_data {
> + int numb;
> +};
> +
> +struct virtbus_object {
> + struct virtbus_device vdev;
> + struct virtbus_data vd;
> +};
> +
> +static struct virtbus_object vo = {
> + .vdev = {
> + .name = "virtual_bus_dev",
> + },
> + .vd = {
> + .numb = 789,
> + },
> +};
> +
> +static int __init test_dev_init(void)
> +{
> + int ret = 0;
> +
> + printk(KERN_INFO "Loading Virtual Bus Test Device\n");
> +
> + printk(KERN_ERR "Virtbus Device values:\n\t%s\n\t%d\n", vo.vdev.name,
> + vo.vd.numb);
> +
> + ret = virtbus_dev_register(&vo.vdev);
> + if (ret) {
> + printk(KERN_ERR "FAILED TO ADD VIRTBUS DEVICE %d\n", ret);
> + return ret;
> + }
> +
> + printk(KERN_INFO "Virtual Device created\n");
> + return ret;
> +}
> +
> +static void __exit test_dev_exit(void)
> +{
> + printk(KERN_INFO "Exiting Virtual Bus Test Device");
> +
> + virtbus_dev_unregister(&vo.vdev);
> +
> + printk(KERN_INFO "Virtual Bus Test Device removed\n");
> +}
> +
> +module_init(test_dev_init);
> +module_exit(test_dev_exit);
> diff --git a/tools/testing/selftests/virtual_bus/virtual_bus_drv/Makefile b/tools/testing/selftests/virtual_bus/virtual_bus_drv/Makefile
> new file mode 100644
> index 000000000000..a4b7467f7878
> --- /dev/null
> +++ b/tools/testing/selftests/virtual_bus/virtual_bus_drv/Makefile
> @@ -0,0 +1,7 @@
> +obj-m += virtual_bus_drv.o
> +
> +all:
> + make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
> +
> +clean:
> + make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean
Add all the test stuff as a follow-on patch, not all in one big mess
here.
> diff --git a/tools/testing/selftests/virtual_bus/virtual_bus_drv/virtual_bus_drv.c b/tools/testing/selftests/virtual_bus/virtual_bus_drv/virtual_bus_drv.c
> new file mode 100644
> index 000000000000..13e2e3d686ab
> --- /dev/null
> +++ b/tools/testing/selftests/virtual_bus/virtual_bus_drv/virtual_bus_drv.c
> @@ -0,0 +1,115 @@
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/module.h>
> +#include <linux/virtual_bus.h>
> +#include <linux/string.h>
> +#include <linux/slab.h>
> +#include <linux/mod_devicetable.h>
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Dave Ertman");
> +MODULE_DESCRIPTION("Test to register a driver on virtual bus");
> +MODULE_VERSION("1.0");
MODULE_VERSION? What is this, the 1990's? :(
> +
> +struct virtbus_data {
> + int numb;
> +};
> +
> +struct virtbus_object {
> + struct virtbus_device vdev;
> + struct virtbus_data vd;
> +};
> +
> +static int td_probe(struct virtbus_device *vdev)
> +{
> + struct virtbus_object *vo;
> +
> + printk(KERN_ERR "VIRTBUS DRIVER PROBED\n");
> +
> + vo = container_of(vdev, struct virtbus_object, vdev);
> +
> + if (vdev->matched_element) {
> + printk(KERN_ERR "DEV_ID->DATA 0x%08x\n",
> + (uint)vdev->matched_element->driver_data);
> + if (vdev->matched_element->driver_data == 1)
> + printk(KERN_ERR "NUMB: %d\n",
> + vo->vd.numb);
> + } else {
> + printk(KERN_ERR "MATCHED_ELEMENT->DATA is NULL\n");
> + }
> +
> + return 0;
> +}
> +
> +static int td_remove(struct virtbus_device *vdev)
> +{
> + printk(KERN_ERR "VIRTBUS DRIVER REMOVED\n");
> + return 0;
> +}
> +
> +static void td_shutdown(struct virtbus_device *vdev)
> +{
> + printk(KERN_ERR "VIRTBUS DRIVER SHUTDOWN\n");
> +}
> +
> +static const struct virtbus_dev_id vdev_id_table[] = {
> +
> + {
> + .name = "NOT THE NAME",
> + .driver_data = 0x00000000,
> + },
> + {
> + .name = "virtual_bus_dev",
> + .driver_data = 0x00000001,
> + },
> + {
> + .name = "ice_rdma",
> + .driver_data = 0x00000002,
> + },
> + {
> + .name = "YET AGAIN NOT NAME",
> + .driver_data = 0x00000003,
> + },
> +};
> +
> +static struct virtbus_driver vdrv = {
> + .probe = td_probe,
> + .remove = td_remove,
> + .shutdown = td_shutdown,
> + .driver = {
> + .name = "virtual_bus_dev",
> + },
> +};
> +
> +static int __init test_drv_init(void)
> +{
> + int ret;
> +
> + printk(KERN_INFO "Registering Virtual Bus Test Driver\n");
> +
> + /* To do a simple match, leave the id_table as NULL */
> + vdrv.id_table = &vdev_id_table[0];
> +
> + printk(KERN_ERR "name of 0 is %s\n", vdrv.id_table->name);
> +
> + ret = virtbus_drv_register(&vdrv);
> +
> + if (!ret)
> + printk(KERN_INFO "Virtual Driver registered\n");
> + else
> + printk(KERN_INFO "Virtual Driver FAILED!!\n");
> +
> + return ret;
> +}
> +
> +static void __exit test_drv_exit(void)
> +{
> + printk(KERN_INFO "Exiting Virtual Bus Test Driver");
> +
> + virtbus_drv_unregister(&vdrv);
> +
> + printk(KERN_INFO "Virtual Bus Test Driver removed\n");
> +}
> +
> +module_init(test_drv_init);
> +module_exit(test_drv_exit);
Odd test, what is it supposed to do? If you use kunit, does that make
it easier to test things out?
thanks,
greg k-h
