mirror of
https://github.com/torvalds/linux.git
synced 2025-11-04 10:40:15 +02:00
1fbaf8fc12
Add a helper that calls remap_pfn_range for an struct io_mapping, relying on the pgprot pre-validation done when creating the mapping instead of doing it at runtime. Link: https://lkml.kernel.org/r/20210326055505.1424432-3-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
29 lines
993 B
C
29 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);
|