[linux.git] / mm / io-mapping.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);
Commit	Line	Data
1fbaf8fc CH	1	// SPDX-License-Identifier: GPL-2.0-only
	2
	3	#include <linux/mm.h>
	4	#include <linux/io-mapping.h>
	5
	6	/**
	7	* io_mapping_map_user - remap an I/O mapping to userspace
	8	* @iomap: the source io_mapping
	9	* @vma: user vma to map to
	10	* @addr: target user address to start at
	11	* @pfn: physical address of kernel memory
	12	* @size: size of map area
	13	*
	14	* Note: this is only safe if the mm semaphore is held when called.
	15	*/
	16	int io_mapping_map_user(struct io_mapping iomap, struct vm_area_struct vma,
	17	unsigned long addr, unsigned long pfn, unsigned long size)
	18	{
	19	vm_flags_t expected_flags = VM_PFNMAP \| VM_DONTEXPAND \| VM_DONTDUMP;
	20
	21	if (WARN_ON_ONCE((vma->vm_flags & expected_flags) != expected_flags))
	22	return -EINVAL;
	23
	24	/* We rely on prevalidation of the io-mapping to skip track_pfn(). */
	25	return remap_pfn_range_notrack(vma, addr, pfn, size,
	26	__pgprot((pgprot_val(iomap->prot) & _PAGE_CACHE_MASK) \|
	27	(pgprot_val(vma->vm_page_prot) & ~_PAGE_CACHE_MASK)));
	28	}
	29	EXPORT_SYMBOL_GPL(io_mapping_map_user);