linux/drivers/gpu/drm/i915/i915_mm.c

/*
 * Copyright © 2014 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 */

#include <linux/mm.h>
#include <linux/io-mapping.h>


#include "i915_drv.h"
#include "i915_mm.h"

struct remap_pfn { … };

#define use_dma(io) …

static inline unsigned long sgt_pfn(const struct remap_pfn *r)
{ … }

static int remap_sg(pte_t *pte, unsigned long addr, void *data)
{ … }

#define EXPECTED_FLAGS …

#if IS_ENABLED(CONFIG_X86)
static int remap_pfn(pte_t *pte, unsigned long addr, void *data)
{ … }

/**
 * remap_io_mapping - remap an IO mapping to userspace
 * @vma: user vma to map to
 * @addr: target user address to start at
 * @pfn: physical address of kernel memory
 * @size: size of map area
 * @iomap: the source io_mapping
 *
 *  Note: this is only safe if the mm semaphore is held when called.
 */
int remap_io_mapping(struct vm_area_struct *vma,
		     unsigned long addr, unsigned long pfn, unsigned long size,
		     struct io_mapping *iomap)
{ … }
#endif

/**
 * remap_io_sg - remap an IO mapping to userspace
 * @vma: user vma to map to
 * @addr: target user address to start at
 * @size: size of map area
 * @sgl: Start sg entry
 * @offset: offset from the start of the page
 * @iobase: Use stored dma address offset by this address or pfn if -1
 *
 *  Note: this is only safe if the mm semaphore is held when called.
 */
int remap_io_sg(struct vm_area_struct *vma,
		unsigned long addr, unsigned long size,
		struct scatterlist *sgl, unsigned long offset,
		resource_size_t iobase)
{ … }