Re: [PATCH char-misc-linus 4/5] misc: mic: Fix sparse warnings andother endianness issues.

From: Greg Kroah-Hartman
Date: Tue Nov 26 2013 - 14:15:33 EST


On Tue, Nov 26, 2013 at 10:14:21AM -0800, Ashutosh Dixit wrote:
> Endianness issues are now consistent as per the documentation in
> host/mic_virtio.h. Note that the host can be both BE or LE whereas the
> card is always LE.
>
> Memory space sparse warnings are fixed for now by using __force. This is
> sufficient for now since the driver depends on x86 but will need to be
> revisited if we support other architectures which treat I/O memory
> differently from system memory.

There's no need for this for 3.13-final, right? No bug fixes are here
that I can tell.

And don't use __force, really, can't you fix this some other way?

> diff --git a/drivers/misc/mic/card/mic_virtio.c b/drivers/misc/mic/card/mic_virtio.c
> index 4dce912..c975c36 100644
> --- a/drivers/misc/mic/card/mic_virtio.c
> +++ b/drivers/misc/mic/card/mic_virtio.c
> @@ -248,17 +248,17 @@ static struct virtqueue *mic_find_vq(struct virtio_device *vdev,
> /* First assign the vring's allocated in host memory */
> vqconfig = mic_vq_config(mvdev->desc) + index;
> memcpy_fromio(&config, vqconfig, sizeof(config));
> - _vr_size = vring_size(config.num, MIC_VIRTIO_RING_ALIGN);
> + _vr_size = vring_size(le16_to_cpu(config.num), MIC_VIRTIO_RING_ALIGN);
> vr_size = PAGE_ALIGN(_vr_size + sizeof(struct _mic_vring_info));
> - va = mic_card_map(mvdev->mdev, config.address, vr_size);
> + va = mic_card_map(mvdev->mdev, le64_to_cpu(config.address), vr_size);
> if (!va)
> return ERR_PTR(-ENOMEM);
> mvdev->vr[index] = va;
> memset_io(va, 0x0, _vr_size);
> - vq = vring_new_virtqueue(index,
> - config.num, MIC_VIRTIO_RING_ALIGN, vdev,
> - false,
> - va, mic_notify, callback, name);
> + vq = vring_new_virtqueue(index, le16_to_cpu(config.num),
> + MIC_VIRTIO_RING_ALIGN, vdev, false,
> + (void __force *)va, mic_notify, callback,
> + name);

Why __force a void * here? That feels wrong.

Can you split the endian fixes up from the user pointer fixes to make it
easier to review/apply?

thanks,

greg k-h
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