Re: [PATCH v8 02/18] vfio: platform: probe to devices on the platform bus

[Antonios Motakis <a.motakis-lrHrjnjw1UfHK3s98zE1ajGjJy/sRE9J@public.gmane.org>]

On Tue, Oct 21, 2014 at 6:37 PM, Eric Auger <eric.auger-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> wrote:
> On 10/21/2014 06:17 PM, Alex Williamson wrote:
>> On Mon, 2014-10-13 at 15:10 +0200, Antonios Motakis wrote:
>>> Driver to bind to Linux platform devices, and callbacks to discover their
>>> resources to be used by the main VFIO PLATFORM code.
>>>
>>> Signed-off-by: Antonios Motakis <a.motakis-lrHrjnjw1UfHK3s98zE1ajGjJy/sRE9J@public.gmane.org>
>>> ---
>>>  drivers/vfio/platform/vfio_platform.c | 107 ++++++++++++++++++++++++++++++++++
>>>  include/uapi/linux/vfio.h             |   1 +
>>>  2 files changed, 108 insertions(+)
>>>  create mode 100644 drivers/vfio/platform/vfio_platform.c
>>>
>>> diff --git a/drivers/vfio/platform/vfio_platform.c b/drivers/vfio/platform/vfio_platform.c
>>> new file mode 100644
>>> index 0000000..baeb7da
>>> --- /dev/null
>>> +++ b/drivers/vfio/platform/vfio_platform.c
>>> @@ -0,0 +1,107 @@
>>> +/*
>>> + * Copyright (C) 2013 - Virtual Open Systems
>>> + * Author: Antonios Motakis <a.motakis-lrHrjnjw1UfHK3s98zE1ajGjJy/sRE9J@public.gmane.org>
>>> + *
>>> + * This program is free software; you can redistribute it and/or modify
>>> + * it under the terms of the GNU General Public License, version 2, as
>>> + * published by the Free Software Foundation.
>>> + *
>>> + * This program is distributed in the hope that it will be useful,
>>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>>> + * GNU General Public License for more details.
>>> + */
>>> +
>>> +#include <linux/device.h>
>>> +#include <linux/eventfd.h>
>>> +#include <linux/interrupt.h>
>>> +#include <linux/iommu.h>
>>> +#include <linux/module.h>
>>> +#include <linux/mutex.h>
>>> +#include <linux/notifier.h>
>>> +#include <linux/pm_runtime.h>
>>> +#include <linux/slab.h>
>>> +#include <linux/types.h>
>>> +#include <linux/uaccess.h>
>>> +#include <linux/vfio.h>
>>> +#include <linux/io.h>
>>> +#include <linux/platform_device.h>
>>> +#include <linux/irq.h>
>>> +
>>> +#include "vfio_platform_private.h"
>>> +
>>> +#define DRIVER_VERSION  "0.8"
>>> +#define DRIVER_AUTHOR   "Antonios Motakis <a.motakis-lrHrjnjw1UfHK3s98zE1ajGjJy/sRE9J@public.gmane.org>"
>>> +#define DRIVER_DESC     "VFIO for platform devices - User Level meta-driver"
>>> +
>>> +/* probing devices from the linux platform bus */
>>> +
>>> +static struct resource *get_platform_resource(struct vfio_platform_device *vdev,
>>> +                                            int num)
>>> +{
>>> +    struct platform_device *dev = (struct platform_device *) vdev->opaque;
>>> +    int i;
>>> +
>>> +    for (i = 0; i < dev->num_resources; i++) {
>>> +            struct resource *r = &dev->resource[i];
>>> +
>>> +            if (resource_type(r) & (IORESOURCE_MEM|IORESOURCE_IO)) {
>>> +                    num--;
>>> +
>>> +                    if (!num)
>>> +                            return r;
>>
>> Has this been tested?  What happens when we call this with num = 0?
> Yep. I confirm I enter that case with my xgmac where the IORESOURCE_MEM
> is the 1st resource. I Just ended to the same cause ;-)

Right, num-- should be after the check, or we miss one region.

>
> Best Regards
>
> Eric
>>
>>> +            }
>>> +    }
>>> +    return NULL;
>>> +}
>>> +
>>> +static int get_platform_irq(struct vfio_platform_device *vdev, int i)
>>> +{
>>> +    struct platform_device *pdev = (struct platform_device *) vdev->opaque;
>>> +
>>> +    return platform_get_irq(pdev, i);
>>> +}
>>> +
>>> +
>>> +static int vfio_platform_probe(struct platform_device *pdev)
>>> +{
>>> +    struct vfio_platform_device *vdev;
>>> +    int ret;
>>> +
>>> +    vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
>>> +    if (!vdev)
>>> +            return -ENOMEM;
>>> +
>>> +    vdev->opaque = (void *) pdev;
>>> +    vdev->name = pdev->name;
>>> +    vdev->flags = VFIO_DEVICE_FLAGS_PLATFORM;
>>> +    vdev->get_resource = get_platform_resource;
>>> +    vdev->get_irq = get_platform_irq;
>>> +
>>> +    ret = vfio_platform_probe_common(vdev, &pdev->dev);
>>> +    if (ret)
>>> +            kfree(vdev);
>>> +
>>> +    return ret;
>>> +}
>>> +
>>> +static int vfio_platform_remove(struct platform_device *pdev)
>>> +{
>>> +    return vfio_platform_remove_common(&pdev->dev);
>>> +}
>>> +
>>> +static struct platform_driver vfio_platform_driver = {
>>> +    .probe          = vfio_platform_probe,
>>> +    .remove         = vfio_platform_remove,
>>> +    .driver = {
>>> +            .name   = "vfio-platform",
>>> +            .owner  = THIS_MODULE,
>>> +    },
>>> +};
>>> +
>>> +module_platform_driver(vfio_platform_driver);
>>> +
>>> +MODULE_VERSION(DRIVER_VERSION);
>>> +MODULE_LICENSE("GPL v2");
>>> +MODULE_AUTHOR(DRIVER_AUTHOR);
>>> +MODULE_DESCRIPTION(DRIVER_DESC);
>>> diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
>>> index 111b5e8..aca6d3e 100644
>>> --- a/include/uapi/linux/vfio.h
>>> +++ b/include/uapi/linux/vfio.h
>>> @@ -158,6 +158,7 @@ struct vfio_device_info {
>>>      __u32   flags;
>>>  #define VFIO_DEVICE_FLAGS_RESET     (1 << 0)        /* Device supports reset */
>>>  #define VFIO_DEVICE_FLAGS_PCI       (1 << 1)        /* vfio-pci device */
>>> +#define VFIO_DEVICE_FLAGS_PLATFORM (1 << 2) /* vfio-platform device */
>>>      __u32   num_regions;    /* Max region index + 1 */
>>>      __u32   num_irqs;       /* Max IRQ index + 1 */
>>>  };
>>
>>
>>
>



-- 
Antonios Motakis
Virtual Open Systems