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