Re: [RFC PATCH v5 09/11] VFIO_PLATFORM: Return IRQ info

[Alex Williamson <alex.williamson-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

On Mon, 2014-04-28 at 17:52 +0200, Antonios Motakis wrote:
> Return information for the interrupts exposed by the device.
> This patch extends VFIO_DEVICE_GET_INFO with the number of IRQs
> and enables VFIO_DEVICE_GET_IRQ_INFO
> 
> Signed-off-by: Antonios Motakis <a.motakis-lrHrjnjw1UfHK3s98zE1ajGjJy/sRE9J@public.gmane.org>
> ---
>  drivers/vfio/platform/Makefile                |  2 +-
>  drivers/vfio/platform/vfio_platform.c         | 35 +++++++++++++--
>  drivers/vfio/platform/vfio_platform_irq.c     | 63 +++++++++++++++++++++++++++
>  drivers/vfio/platform/vfio_platform_private.h | 11 +++++
>  4 files changed, 106 insertions(+), 5 deletions(-)
>  create mode 100644 drivers/vfio/platform/vfio_platform_irq.c
> 
> diff --git a/drivers/vfio/platform/Makefile b/drivers/vfio/platform/Makefile
> index df3a014..2c53327 100644
> --- a/drivers/vfio/platform/Makefile
> +++ b/drivers/vfio/platform/Makefile
> @@ -1,4 +1,4 @@
>  
> -vfio-platform-y := vfio_platform.o
> +vfio-platform-y := vfio_platform.o vfio_platform_irq.o
>  
>  obj-$(CONFIG_VFIO_PLATFORM) += vfio-platform.o
> diff --git a/drivers/vfio/platform/vfio_platform.c b/drivers/vfio/platform/vfio_platform.c
> index 37beff3..2e16595 100644
> --- a/drivers/vfio/platform/vfio_platform.c
> +++ b/drivers/vfio/platform/vfio_platform.c
> @@ -79,6 +79,7 @@ static void vfio_platform_release(void *device_data)
>  	struct vfio_platform_device *vdev = device_data;
>  
>  	vfio_platform_regions_cleanup(vdev);
> +	vfio_platform_irq_cleanup(vdev);
>  
>  	module_put(THIS_MODULE);
>  }
> @@ -92,12 +93,22 @@ static int vfio_platform_open(void *device_data)
>  	if (ret)
>  		return ret;
>  
> +	ret = vfio_platform_irq_init(vdev);
> +	if (ret)
> +		goto err_irq;
> +
>  	if (!try_module_get(THIS_MODULE)) {
> -		vfio_platform_regions_cleanup(vdev);
> -		return -ENODEV;
> +		ret = -ENODEV;
> +		goto err_mod;
>  	}


Same comments from REGION_INFO patch apply here.  Ordering above,
paranoia about keeping num_irqs consistent with allocation, nit about
local variable use in initialization loop.  Thanks,

Alex
>  
>  	return 0;
> +
> +err_mod:
> +	vfio_platform_irq_cleanup(vdev);
> +err_irq:
> +	vfio_platform_regions_cleanup(vdev);
> +	return ret;
>  }
>  
>  static long vfio_platform_ioctl(void *device_data,
> @@ -119,7 +130,7 @@ static long vfio_platform_ioctl(void *device_data,
>  
>  		info.flags = VFIO_DEVICE_FLAGS_PLATFORM;
>  		info.num_regions = vdev->num_regions;
> -		info.num_irqs = 0;
> +		info.num_irqs = vdev->num_irqs;
>  
>  		return copy_to_user((void __user *)arg, &info, minsz);
>  
> @@ -145,7 +156,23 @@ static long vfio_platform_ioctl(void *device_data,
>  		return copy_to_user((void __user *)arg, &info, minsz);
>  
>  	} else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
> -		return -EINVAL;
> +		struct vfio_irq_info info;
> +
> +		minsz = offsetofend(struct vfio_irq_info, count);
> +
> +		if (copy_from_user(&info, (void __user *)arg, minsz))
> +			return -EFAULT;
> +
> +		if (info.argsz < minsz)
> +			return -EINVAL;
> +
> +		if (info.index >= vdev->num_irqs)
> +			return -EINVAL;
> +
> +		info.flags = vdev->irq[info.index].flags;
> +		info.count = vdev->irq[info.index].count;
> +
> +		return copy_to_user((void __user *)arg, &info, minsz);
>  
>  	} else if (cmd == VFIO_DEVICE_SET_IRQS)
>  		return -EINVAL;
> diff --git a/drivers/vfio/platform/vfio_platform_irq.c b/drivers/vfio/platform/vfio_platform_irq.c
> new file mode 100644
> index 0000000..075c401
> --- /dev/null
> +++ b/drivers/vfio/platform/vfio_platform_irq.c
> @@ -0,0 +1,63 @@
> +/*
> + * VFIO platform devices interrupt handling
> + *
> + * 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/platform_device.h>
> +#include <linux/irq.h>
> +
> +#include "vfio_platform_private.h"
> +
> +int vfio_platform_irq_init(struct vfio_platform_device *vdev)
> +{
> +	int cnt = 0, i;
> +
> +	while (platform_get_irq(vdev->pdev, cnt) > 0)
> +		cnt++;
> +
> +	vdev->num_irqs = cnt;
> +
> +	vdev->irq = kzalloc(sizeof(struct vfio_platform_irq) * vdev->num_irqs,
> +				GFP_KERNEL);
> +	if (!vdev->irq)
> +		return -ENOMEM;
> +
> +	for (i = 0; i < cnt; i++) {
> +		struct vfio_platform_irq irq;
> +
> +		irq.flags = 0;
> +		irq.count = 1;
> +
> +		vdev->irq[i] = irq;
> +	}
> +
> +	return 0;
> +}
> +
> +void vfio_platform_irq_cleanup(struct vfio_platform_device *vdev)
> +{
> +	kfree(vdev->irq);
> +}
> diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
> index 3448f918..9776cff 100644
> --- a/drivers/vfio/platform/vfio_platform_private.h
> +++ b/drivers/vfio/platform/vfio_platform_private.h
> @@ -24,6 +24,11 @@
>  #define VFIO_PLATFORM_INDEX_TO_OFFSET(index)	\
>  	((u64)(index) << VFIO_PLATFORM_OFFSET_SHIFT)
>  
> +struct vfio_platform_irq {
> +	u32			flags;
> +	u32			count;
> +};
> +
>  struct vfio_platform_region {
>  	u64			addr;
>  	resource_size_t		size;
> @@ -34,6 +39,12 @@ struct vfio_platform_device {
>  	struct platform_device		*pdev;
>  	struct vfio_platform_region	*region;
>  	u32				num_regions;
> +	struct vfio_platform_irq	*irq;
> +	u32				num_irqs;
>  };
>  
> +extern int vfio_platform_irq_init(struct vfio_platform_device *vdev);
> +
> +extern void vfio_platform_irq_cleanup(struct vfio_platform_device *vdev);
> +
>  #endif /* VFIO_PLATFORM_PRIVATE_H */