From 3b81ac2bdcff0f611cad468329cc726600bb23ba Mon Sep 17 00:00:00 2001 From: Diana Craciun Date: Fri, 27 Sep 2019 16:40:34 +0300 Subject: [PATCH] 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 Signed-off-by: Diana Craciun --- drivers/vfio/fsl-mc/vfio_fsl_mc.c | 65 +++++++++++++++++++++++++++++++++++++-- 1 file changed, 63 insertions(+), 2 deletions(-) --- a/drivers/vfio/fsl-mc/vfio_fsl_mc.c +++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c @@ -32,7 +32,10 @@ static int vfio_fsl_mc_regions_init(stru vdev->regions[i].addr = res->start; vdev->regions[i].size = PAGE_ALIGN((resource_size(res))); - vdev->regions[i].flags = 0; + vdev->regions[i].flags = VFIO_REGION_INFO_FLAG_MMAP; + vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_READ; + if (!(mc_dev->regions[i].flags & IORESOURCE_READONLY)) + vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_WRITE; } vdev->num_regions = mc_dev->obj_desc.region_count; @@ -163,10 +166,68 @@ static ssize_t vfio_fsl_mc_write(void *d 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; + + 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; + + 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; + unsigned long size, addr; + 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; + + addr = vdev->regions[index].addr; + size = vdev->regions[index].size; + + vma->vm_private_data = mc_dev; + + return vfio_fsl_mc_mmap_mmio(vdev->regions[index], vma); + + return -EFAULT; } + static int vfio_fsl_mc_init_device(struct vfio_fsl_mc_device *vdev) { struct fsl_mc_device *mc_dev = vdev->mc_dev;