| 1 | // SPDX-License-Identifier: GPL-2.0-only |
|---|---|
| 2 | |
| 3 | #include <linux/mm.h> |
| 4 | #include <linux/io-mapping.h> |
| 5 | |
| 6 | /** |
| 7 | * io_mapping_map_user - remap an I/O mapping to userspace |
| 8 | * @iomap: the source io_mapping |
| 9 | * @vma: user vma to map to |
| 10 | * @addr: target user address to start at |
| 11 | * @pfn: physical address of kernel memory |
| 12 | * @size: size of map area |
| 13 | * |
| 14 | * Note: this is only safe if the mm semaphore is held when called. |
| 15 | */ |
| 16 | int io_mapping_map_user(struct io_mapping *iomap, struct vm_area_struct *vma, |
| 17 | unsigned long addr, unsigned long pfn, unsigned long size) |
| 18 | { |
| 19 | vm_flags_t expected_flags = VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP; |
| 20 | |
| 21 | if (WARN_ON_ONCE((vma->vm_flags & expected_flags) != expected_flags)) |
| 22 | return -EINVAL; |
| 23 | |
| 24 | /* We rely on prevalidation of the io-mapping to skip track_pfn(). */ |
| 25 | return remap_pfn_range_notrack(vma, addr, pfn, size, |
| 26 | __pgprot((pgprot_val(iomap->prot) & _PAGE_CACHE_MASK) | |
| 27 | (pgprot_val(vma->vm_page_prot) & ~_PAGE_CACHE_MASK))); |
| 28 | } |
| 29 | EXPORT_SYMBOL_GPL(io_mapping_map_user); |
| 30 |