On Mon, 6 Jul 2020 18:41:48 +0300
Diana Craciun <diana.craciun@xxxxxxxxxxx> wrote:
> Expose to userspace information about the memory regions.
>
> Signed-off-by: Bharat Bhushan <Bharat.Bhushan@xxxxxxx>
> Signed-off-by: Diana Craciun <diana.craciun@xxxxxxxxxxx>
> ---
> drivers/vfio/fsl-mc/vfio_fsl_mc.c | 77 ++++++++++++++++++++++-
> drivers/vfio/fsl-mc/vfio_fsl_mc_private.h | 19 ++++++
> 2 files changed, 95 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc.c b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
> index 937b6eddc71a..10bd9f78b8de 100644
> --- a/drivers/vfio/fsl-mc/vfio_fsl_mc.c
> +++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
> @@ -17,16 +17,72 @@
>
> static struct fsl_mc_driver vfio_fsl_mc_driver;
>
> +static int vfio_fsl_mc_regions_init(struct vfio_fsl_mc_device *vdev)
> +{
> + struct fsl_mc_device *mc_dev = vdev->mc_dev;
> + int count = mc_dev->obj_desc.region_count;
> + int i;
> +
> + vdev->regions = kcalloc(count, sizeof(struct vfio_fsl_mc_region),
> + GFP_KERNEL);
> + if (!vdev->regions)
> + return -ENOMEM;
> +
> + for (i = 0; i < count; i++) {
> + struct resource *res = &mc_dev->regions[i];
> +
> + vdev->regions[i].addr = res->start;
> + vdev->regions[i].size = resource_size(res);
> + vdev->regions[i].flags = 0;
> + }
> +
> + vdev->num_regions = mc_dev->obj_desc.region_count;
> + return 0;
> +}
> +
> +static void vfio_fsl_mc_regions_cleanup(struct vfio_fsl_mc_device *vdev)
> +{
> + vdev->num_regions = 0;
> + kfree(vdev->regions);
> +}
> +
> static int vfio_fsl_mc_open(void *device_data)
> {
> + struct vfio_fsl_mc_device *vdev = device_data;
> + int ret;
> +
> if (!try_module_get(THIS_MODULE))
> return -ENODEV;
>
> + mutex_lock(&vdev->driver_lock);
> + if (!vdev->refcnt) {
> + ret = vfio_fsl_mc_regions_init(vdev);
> + if (ret)
> + goto err_reg_init;
> + }
> + vdev->refcnt++;
> +
> + mutex_unlock(&vdev->driver_lock);
> +
> return 0;
> +
> +err_reg_init:
> + mutex_unlock(&vdev->driver_lock);
> + module_put(THIS_MODULE);
> + return ret;
> }
>
> static void vfio_fsl_mc_release(void *device_data)
> {
> + struct vfio_fsl_mc_device *vdev = device_data;
> +
> + mutex_lock(&vdev->driver_lock);
> +
> + if (!(--vdev->refcnt))
> + vfio_fsl_mc_regions_cleanup(vdev);
> +
> + mutex_unlock(&vdev->driver_lock);
> +
> module_put(THIS_MODULE);
> }
>
> @@ -59,7 +115,25 @@ static long vfio_fsl_mc_ioctl(void *device_data, unsigned int cmd,
> }
> case VFIO_DEVICE_GET_REGION_INFO:
> {
> - return -ENOTTY;
> + struct vfio_region_info info;
> +
> + minsz = offsetofend(struct vfio_region_info, offset);
> +
> + if (copy_from_user(&info, (void __user *)arg, minsz))
> + return -EFAULT;
> +
> + if (info.argsz < minsz)
> + return -EINVAL;
> +
> + if (info.index >= vdev->num_regions)
> + return -EINVAL;
> +
> + /* map offset to the physical address */
> + info.offset = VFIO_FSL_MC_INDEX_TO_OFFSET(info.index);
> + info.size = vdev->regions[info.index].size;
> + info.flags = vdev->regions[info.index].flags;
> +
> + return copy_to_user((void __user *)arg, &info, minsz);
> }
> case VFIO_DEVICE_GET_IRQ_INFO:
> {
> @@ -201,6 +275,7 @@ static int vfio_fsl_mc_probe(struct fsl_mc_device *mc_dev)
> vfio_iommu_group_put(group, dev);
> return ret;
> }
> + mutex_init(&vdev->driver_lock);
Consider all calling mutex_destory() in the remove callback, it's only
used for lock debugging, so we're only partially successful in calling
it. Thanks,
Alex
>
> return ret;
> }
> diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h b/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h
> index 37d61eaa58c8..818dfd3df4db 100644
> --- a/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h
> +++ b/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h
> @@ -7,9 +7,28 @@
> #ifndef VFIO_FSL_MC_PRIVATE_H
> #define VFIO_FSL_MC_PRIVATE_H
>
> +#define VFIO_FSL_MC_OFFSET_SHIFT 40
> +#define VFIO_FSL_MC_OFFSET_MASK (((u64)(1) << VFIO_FSL_MC_OFFSET_SHIFT) - 1)
> +
> +#define VFIO_FSL_MC_OFFSET_TO_INDEX(off) ((off) >> VFIO_FSL_MC_OFFSET_SHIFT)
> +
> +#define VFIO_FSL_MC_INDEX_TO_OFFSET(index) \
> + ((u64)(index) << VFIO_FSL_MC_OFFSET_SHIFT)
> +
> +struct vfio_fsl_mc_region {
> + u32 flags;
> + u32 type;
> + u64 addr;
> + resource_size_t size;
> +};
> +
> struct vfio_fsl_mc_device {
> struct fsl_mc_device *mc_dev;
> struct notifier_block nb;
> + int refcnt;
> + u32 num_regions;
> + struct vfio_fsl_mc_region *regions;
> + struct mutex driver_lock;
> };
>
> #endif /* VFIO_FSL_MC_PRIVATE_H */
