1*1fbaf8fcSChristoph Hellwig // SPDX-License-Identifier: GPL-2.0-only
2*1fbaf8fcSChristoph Hellwig
3*1fbaf8fcSChristoph Hellwig #include <linux/mm.h>
4*1fbaf8fcSChristoph Hellwig #include <linux/io-mapping.h>
5*1fbaf8fcSChristoph Hellwig
6*1fbaf8fcSChristoph Hellwig /**
7*1fbaf8fcSChristoph Hellwig * io_mapping_map_user - remap an I/O mapping to userspace
8*1fbaf8fcSChristoph Hellwig * @iomap: the source io_mapping
9*1fbaf8fcSChristoph Hellwig * @vma: user vma to map to
10*1fbaf8fcSChristoph Hellwig * @addr: target user address to start at
11*1fbaf8fcSChristoph Hellwig * @pfn: physical address of kernel memory
12*1fbaf8fcSChristoph Hellwig * @size: size of map area
13*1fbaf8fcSChristoph Hellwig *
14*1fbaf8fcSChristoph Hellwig * Note: this is only safe if the mm semaphore is held when called.
15*1fbaf8fcSChristoph Hellwig */
io_mapping_map_user(struct io_mapping * iomap,struct vm_area_struct * vma,unsigned long addr,unsigned long pfn,unsigned long size)16*1fbaf8fcSChristoph Hellwig int io_mapping_map_user(struct io_mapping *iomap, struct vm_area_struct *vma,
17*1fbaf8fcSChristoph Hellwig unsigned long addr, unsigned long pfn, unsigned long size)
18*1fbaf8fcSChristoph Hellwig {
19*1fbaf8fcSChristoph Hellwig vm_flags_t expected_flags = VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
20*1fbaf8fcSChristoph Hellwig
21*1fbaf8fcSChristoph Hellwig if (WARN_ON_ONCE((vma->vm_flags & expected_flags) != expected_flags))
22*1fbaf8fcSChristoph Hellwig return -EINVAL;
23*1fbaf8fcSChristoph Hellwig
24*1fbaf8fcSChristoph Hellwig /* We rely on prevalidation of the io-mapping to skip track_pfn(). */
25*1fbaf8fcSChristoph Hellwig return remap_pfn_range_notrack(vma, addr, pfn, size,
26*1fbaf8fcSChristoph Hellwig __pgprot((pgprot_val(iomap->prot) & _PAGE_CACHE_MASK) |
27*1fbaf8fcSChristoph Hellwig (pgprot_val(vma->vm_page_prot) & ~_PAGE_CACHE_MASK)));
28*1fbaf8fcSChristoph Hellwig }
29*1fbaf8fcSChristoph Hellwig EXPORT_SYMBOL_GPL(io_mapping_map_user);
30