Hi Diana, On 8/26/20 11:33 AM, Diana Craciun wrote: > 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 | 60 +++++++++++++++++++++++++++++-- > 1 file changed, 58 insertions(+), 2 deletions(-) > > diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc.c > b/drivers/vfio/fsl-mc/vfio_fsl_mc.c > index 093b8d68496c..64d5c1fff51f 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; Is the region always mmappable or does it depend on the mc_dev->regions[i].flags. Also on VFIO platform we checked some alignment addr/size constraints. > + vdev->regions[i].type = mc_dev->regions[i].flags & > IORESOURCE_BITS; > } > > vdev->num_regions = mc_dev->obj_desc.region_count; > @@ -164,9 +165,64 @@ 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); I see in fsl-mc-bus.c that IORESOURCE_CACHEABLE and IORESOURCE_MEM are set on the regions flag? > + 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 = { > Thanks
Eric
