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- // 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);
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