Allow userspace to mmap device regions for direct access of fsl-mc devices.
Signed-off-by: Bharat Bhushan <[email protected]> Signed-off-by: Diana Craciun <[email protected]> --- drivers/vfio/fsl-mc/vfio_fsl_mc.c | 59 +++++++++++++++++++++++++++++-- 1 file changed, 57 insertions(+), 2 deletions(-) diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc.c b/drivers/vfio/fsl-mc/vfio_fsl_mc.c index 10bd9f78b8de..37ccc7d2acbc 100644 --- a/drivers/vfio/fsl-mc/vfio_fsl_mc.c +++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c @@ -33,7 +33,8 @@ static int vfio_fsl_mc_regions_init(struct vfio_fsl_mc_device *vdev) vdev->regions[i].addr = res->start; vdev->regions[i].size = resource_size(res); - vdev->regions[i].flags = 0; + vdev->regions[i].flags = VFIO_REGION_INFO_FLAG_MMAP; + vdev->regions[i].type = mc_dev->regions[i].flags & IORESOURCE_BITS; } vdev->num_regions = mc_dev->obj_desc.region_count; @@ -164,9 +165,63 @@ static ssize_t vfio_fsl_mc_write(void *device_data, const char __user *buf, return -EINVAL; } +static int vfio_fsl_mc_mmap_mmio(struct vfio_fsl_mc_region region, + struct vm_area_struct *vma) +{ + u64 size = vma->vm_end - vma->vm_start; + u64 pgoff, base; + u8 region_cacheable; + + pgoff = vma->vm_pgoff & + ((1U << (VFIO_FSL_MC_OFFSET_SHIFT - PAGE_SHIFT)) - 1); + base = pgoff << PAGE_SHIFT; + + if (region.size < PAGE_SIZE || base + size > region.size) + return -EINVAL; + + region_cacheable = (region.type & FSL_MC_REGION_CACHEABLE) && (region.type & FSL_MC_REGION_SHAREABLE); + if (!region_cacheable) + vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); + + vma->vm_pgoff = (region.addr >> PAGE_SHIFT) + pgoff; + + return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff, + size, vma->vm_page_prot); +} + static int vfio_fsl_mc_mmap(void *device_data, struct vm_area_struct *vma) { - return -EINVAL; + struct vfio_fsl_mc_device *vdev = device_data; + struct fsl_mc_device *mc_dev = vdev->mc_dev; + int index; + + index = vma->vm_pgoff >> (VFIO_FSL_MC_OFFSET_SHIFT - PAGE_SHIFT); + + if (vma->vm_end < vma->vm_start) + return -EINVAL; + if (vma->vm_start & ~PAGE_MASK) + return -EINVAL; + if (vma->vm_end & ~PAGE_MASK) + return -EINVAL; + if (!(vma->vm_flags & VM_SHARED)) + return -EINVAL; + if (index >= vdev->num_regions) + return -EINVAL; + + if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_MMAP)) + return -EINVAL; + + if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ) + && (vma->vm_flags & VM_READ)) + return -EINVAL; + + if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE) + && (vma->vm_flags & VM_WRITE)) + return -EINVAL; + + vma->vm_private_data = mc_dev; + + return vfio_fsl_mc_mmap_mmio(vdev->regions[index], vma); } static const struct vfio_device_ops vfio_fsl_mc_ops = { -- 2.17.1
