// SPDX-License-Identifier: GPL-2.0-only #include <linux/mm.h> #include <linux/io-mapping.h> /** * io_mapping_map_user - remap an I/O mapping to userspace * @iomap: the source io_mapping * @vma: user vma to map to * @addr: target user address to start at * @pfn: physical address of kernel memory * @size: size of map area * * Note: this is only safe if the mm semaphore is held when called. */ int io_mapping_map_user(struct io_mapping *iomap, struct vm_area_struct *vma, unsigned long addr, unsigned long pfn, unsigned long size) { vm_flags_t expected_flags = VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP; if (WARN_ON_ONCE((vma->vm_flags & expected_flags) != expected_flags)) return -EINVAL; /* We rely on prevalidation of the io-mapping to skip track_pfn(). */ return remap_pfn_range_notrack(vma, addr, pfn, size, __pgprot((pgprot_val(iomap->prot) & _PAGE_CACHE_MASK) | (pgprot_val(vma->vm_page_prot) & ~_PAGE_CACHE_MASK))); } EXPORT_SYMBOL_GPL(io_mapping_map_user);