target/linux/layerscape/patches-5.4/821-vfio-0005-vfio-fsl-mc-Allow-userspace-to-MMAP-fsl-mc-device-MM.patch

   1 From 3b81ac2bdcff0f611cad468329cc726600bb23ba Mon Sep 17 00:00:00 2001
   2 From: Diana Craciun <diana.craciun@nxp.com>
   3 Date: Fri, 27 Sep 2019 16:40:34 +0300
   4 Subject: [PATCH] vfio/fsl-mc: Allow userspace to MMAP fsl-mc device MMIO
   5  regions
   6
   7 Allow userspace to mmap device regions for direct access of
   8 fsl-mc devices.
   9
  10 Signed-off-by: Bharat Bhushan <Bharat.Bhushan@nxp.com>
  11 Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
  12 ---
  13  drivers/vfio/fsl-mc/vfio_fsl_mc.c | 65 +++++++++++++++++++++++++++++++++++++--
  14  1 file changed, 63 insertions(+), 2 deletions(-)
  15
  16 --- a/drivers/vfio/fsl-mc/vfio_fsl_mc.c
  17 +++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
  18 @@ -32,7 +32,10 @@ static int vfio_fsl_mc_regions_init(stru
  19
  20                 vdev->regions[i].addr = res->start;
  21                 vdev->regions[i].size = PAGE_ALIGN((resource_size(res)));
  22 -               vdev->regions[i].flags = 0;
  23 +               vdev->regions[i].flags = VFIO_REGION_INFO_FLAG_MMAP;
  24 +               vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_READ;
  25 +               if (!(mc_dev->regions[i].flags & IORESOURCE_READONLY))
  26 +                       vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_WRITE;
  27         }
  28
  29         vdev->num_regions = mc_dev->obj_desc.region_count;
  30 @@ -163,10 +166,68 @@ static ssize_t vfio_fsl_mc_write(void *d
  31         return -EINVAL;
  32  }
  33
  34 +static int vfio_fsl_mc_mmap_mmio(struct vfio_fsl_mc_region region,
  35 +                                struct vm_area_struct *vma)
  36 +{
  37 +       u64 size = vma->vm_end - vma->vm_start;
  38 +       u64 pgoff, base;
  39 +
  40 +       pgoff = vma->vm_pgoff &
  41 +               ((1U << (VFIO_FSL_MC_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
  42 +       base = pgoff << PAGE_SHIFT;
  43 +
  44 +       if (region.size < PAGE_SIZE || base + size > region.size)
  45 +               return -EINVAL;
  46 +
  47 +       vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
  48 +
  49 +       vma->vm_pgoff = (region.addr >> PAGE_SHIFT) + pgoff;
  50 +
  51 +       return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
  52 +                              size, vma->vm_page_prot);
  53 +}
  54 +
  55  static int vfio_fsl_mc_mmap(void *device_data, struct vm_area_struct *vma)
  56  {
  57 -       return -EINVAL;
  58 +       struct vfio_fsl_mc_device *vdev = device_data;
  59 +       struct fsl_mc_device *mc_dev = vdev->mc_dev;
  60 +       unsigned long size, addr;
  61 +       int index;
  62 +
  63 +       index = vma->vm_pgoff >> (VFIO_FSL_MC_OFFSET_SHIFT - PAGE_SHIFT);
  64 +
  65 +       if (vma->vm_end < vma->vm_start)
  66 +               return -EINVAL;
  67 +       if (vma->vm_start & ~PAGE_MASK)
  68 +               return -EINVAL;
  69 +       if (vma->vm_end & ~PAGE_MASK)
  70 +               return -EINVAL;
  71 +       if (!(vma->vm_flags & VM_SHARED))
  72 +               return -EINVAL;
  73 +       if (index >= vdev->num_regions)
  74 +               return -EINVAL;
  75 +
  76 +       if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_MMAP))
  77 +               return -EINVAL;
  78 +
  79 +       if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ)
  80 +                       && (vma->vm_flags & VM_READ))
  81 +               return -EINVAL;
  82 +
  83 +       if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE)
  84 +                       && (vma->vm_flags & VM_WRITE))
  85 +               return -EINVAL;
  86 +
  87 +       addr = vdev->regions[index].addr;
  88 +       size = vdev->regions[index].size;
  89 +
  90 +       vma->vm_private_data = mc_dev;
  91 +
  92 +       return vfio_fsl_mc_mmap_mmio(vdev->regions[index], vma);
  93 +
  94 +       return -EFAULT;
  95  }
  96 +
  97  static int vfio_fsl_mc_init_device(struct vfio_fsl_mc_device *vdev)
  98  {
  99         struct fsl_mc_device *mc_dev = vdev->mc_dev;