30 lines
993 B
C
30 lines
993 B
C
|
// 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);
|