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vfio/fsl-mc: Allow userspace to MMAP fsl-mc device MMIO regions 

Allow userspace to mmap device regions for direct access of
fsl-mc devices.

Signed-off-by: Bharat Bhushan <Bharat.Bhushan@nxp.com>
Signed-off-by: Diana Craciun <diana.craciun@oss.nxp.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This commit is contained in:
Diana Craciun 2020-10-05 20:36:49 +03:00 committed by Alex Williamson
parent df747bcd5b
commit 6724728968
1 changed files with 66 additions and 2 deletions
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68
drivers/vfio/fsl-mc/vfio_fsl_mc.c
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@ -30,11 +30,20 @@ static int vfio_fsl_mc_regions_init(struct vfio_fsl_mc_device *vdev)
for (i = 0; i < count; i++) {
struct resource *res = &mc_dev->regions[i];
int no_mmap = is_fsl_mc_bus_dprc(mc_dev);
vdev->regions[i].addr = res->start;
vdev->regions[i].size = resource_size(res);
vdev->regions[i].flags = 0;
vdev->regions[i].type = mc_dev->regions[i].flags & IORESOURCE_BITS;
/*
* Only regions addressed with PAGE granularity may be
* MMAPed securely.
*/
if (!no_mmap && !(vdev->regions[i].addr & ~PAGE_MASK) &&
!(vdev->regions[i].size & ~PAGE_MASK))
vdev->regions[i].flags |=
VFIO_REGION_INFO_FLAG_MMAP;
}
return 0;
@ -163,9 +172,64 @@ 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 >= mc_dev->obj_desc.region_count)
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 = {