Make use of the new mmap_prepare functionality to perform an I/O remap in favour of the deprecated f_op->mmap hook, hooking the success path to correctly update the users refcount.
Signed-off-by: Lorenzo Stoakes <[email protected]> --- drivers/iommu/iommufd/main.c | 47 ++++++++++++++++++++---------------- 1 file changed, 26 insertions(+), 21 deletions(-) diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c index 15af7ced0501..b8b9c0e7520d 100644 --- a/drivers/iommu/iommufd/main.c +++ b/drivers/iommu/iommufd/main.c @@ -535,46 +535,51 @@ static const struct vm_operations_struct iommufd_vma_ops = { .close = iommufd_fops_vma_close, }; +static int iommufd_fops_mmap_success(const struct vm_area_struct *vma) +{ + struct iommufd_mmap *immap = vma->vm_private_data; + + /* vm_ops.open won't be called for mmap itself. */ + refcount_inc(&immap->owner->users); + + return 0; +} + /* The vm_pgoff must be pre-allocated from mt_mmap, and given to user space */ -static int iommufd_fops_mmap(struct file *filp, struct vm_area_struct *vma) +static int iommufd_fops_mmap_prepare(struct vm_area_desc *desc) { + struct file *filp = desc->file; struct iommufd_ctx *ictx = filp->private_data; - size_t length = vma->vm_end - vma->vm_start; + const size_t length = vma_desc_size(desc); struct iommufd_mmap *immap; - int rc; if (!PAGE_ALIGNED(length)) return -EINVAL; - if (!(vma->vm_flags & VM_SHARED)) + if (!(desc->vm_flags & VM_SHARED)) return -EINVAL; - if (vma->vm_flags & VM_EXEC) + if (desc->vm_flags & VM_EXEC) return -EPERM; - /* vma->vm_pgoff carries a page-shifted start position to an immap */ - immap = mtree_load(&ictx->mt_mmap, vma->vm_pgoff << PAGE_SHIFT); + /* desc->pgoff carries a page-shifted start position to an immap */ + immap = mtree_load(&ictx->mt_mmap, desc->pgoff << PAGE_SHIFT); if (!immap) return -ENXIO; /* * mtree_load() returns the immap for any contained mmio_addr, so only * allow the exact immap thing to be mapped */ - if (vma->vm_pgoff != immap->vm_pgoff || length != immap->length) + if (desc->pgoff != immap->vm_pgoff || length != immap->length) return -ENXIO; - vma->vm_pgoff = 0; - vma->vm_private_data = immap; - vma->vm_ops = &iommufd_vma_ops; - vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); + desc->pgoff = 0; + desc->private_data = immap; + desc->vm_ops = &iommufd_vma_ops; + desc->page_prot = pgprot_noncached(desc->page_prot); - rc = io_remap_pfn_range(vma, vma->vm_start, - immap->mmio_addr >> PAGE_SHIFT, length, - vma->vm_page_prot); - if (rc) - return rc; + mmap_action_ioremap_full(desc, immap->mmio_addr >> PAGE_SHIFT); + desc->action.success_hook = iommufd_fops_mmap_success; - /* vm_ops.open won't be called for mmap itself. */ - refcount_inc(&immap->owner->users); - return rc; + return 0; } static const struct file_operations iommufd_fops = { @@ -582,7 +587,7 @@ static const struct file_operations iommufd_fops = { .open = iommufd_fops_open, .release = iommufd_fops_release, .unlocked_ioctl = iommufd_fops_ioctl, - .mmap = iommufd_fops_mmap, + .mmap_prepare = iommufd_fops_mmap_prepare, }; /** -- 2.51.0
