[linux-2.6-block.git] / 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 {
	struct mm_struct *mm;
	unsigned long pfn;
	pgprot_t prot;

	struct sgt_iter sgt;
	resource_size_t iobase;
};

#define use_dma(io) ((io) != -1)

static inline unsigned long sgt_pfn(const struct remap_pfn *r)
{
	if (use_dma(r->iobase))
		return (r->sgt.dma + r->sgt.curr + r->iobase) >> PAGE_SHIFT;
	else
		return r->sgt.pfn + (r->sgt.curr >> PAGE_SHIFT);
}

static int remap_sg(pte_t *pte, unsigned long addr, void *data)
{
	struct remap_pfn *r = data;

	if (GEM_WARN_ON(!r->sgt.sgp))
		return -EINVAL;

	/* Special PTE are not associated with any struct page */
	set_pte_at(r->mm, addr, pte,
		   pte_mkspecial(pfn_pte(sgt_pfn(r), r->prot)));
	r->pfn++; /* track insertions in case we need to unwind later */

	r->sgt.curr += PAGE_SIZE;
	if (r->sgt.curr >= r->sgt.max)
		r->sgt = __sgt_iter(__sg_next(r->sgt.sgp), use_dma(r->iobase));

	return 0;
}

#define EXPECTED_FLAGS (VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP)

#if IS_ENABLED(CONFIG_X86)
static int remap_pfn(pte_t *pte, unsigned long addr, void *data)
{
	struct remap_pfn *r = data;

	/* Special PTE are not associated with any struct page */
	set_pte_at(r->mm, addr, pte, pte_mkspecial(pfn_pte(r->pfn, r->prot)));
	r->pfn++;

	return 0;
}

/**
 * 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)
{
	struct remap_pfn r;
	int err;

	GEM_BUG_ON((vma->vm_flags & EXPECTED_FLAGS) != EXPECTED_FLAGS);

	/* We rely on prevalidation of the io-mapping to skip track_pfn(). */
	r.mm = vma->vm_mm;
	r.pfn = pfn;
	r.prot = __pgprot((pgprot_val(iomap->prot) & _PAGE_CACHE_MASK) |
			  (pgprot_val(vma->vm_page_prot) & ~_PAGE_CACHE_MASK));

	err = apply_to_page_range(r.mm, addr, size, remap_pfn, &r);
	if (unlikely(err)) {
		zap_vma_ptes(vma, addr, (r.pfn - pfn) << PAGE_SHIFT);
		return err;
	}

	return 0;
}
#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
 * @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, resource_size_t iobase)
{
	struct remap_pfn r = {
		.mm = vma->vm_mm,
		.prot = vma->vm_page_prot,
		.sgt = __sgt_iter(sgl, use_dma(iobase)),
		.iobase = iobase,
	};
	int err;

	/* We rely on prevalidation of the io-mapping to skip track_pfn(). */
	GEM_BUG_ON((vma->vm_flags & EXPECTED_FLAGS) != EXPECTED_FLAGS);

	if (!use_dma(iobase))
		flush_cache_range(vma, addr, size);

	err = apply_to_page_range(r.mm, addr, size, remap_sg, &r);
	if (unlikely(err)) {
		zap_vma_ptes(vma, addr, r.pfn << PAGE_SHIFT);
		return err;
	}

	return 0;
}
Commit	Line	Data
c58305af CW	1	/*
	2	* Copyright © 2014 Intel Corporation
	3	*
	4	* Permission is hereby granted, free of charge, to any person obtaining a
	5	* copy of this software and associated documentation files (the "Software"),
	6	* to deal in the Software without restriction, including without limitation
	7	* the rights to use, copy, modify, merge, publish, distribute, sublicense,
	8	* and/or sell copies of the Software, and to permit persons to whom the
	9	* Software is furnished to do so, subject to the following conditions:
	10	*
	11	* The above copyright notice and this permission notice (including the next
	12	* paragraph) shall be included in all copies or substantial portions of the
	13	* Software.
	14	*
	15	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	16	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	17	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	18	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	19	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
	20	* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
	21	* IN THE SOFTWARE.
	22	*
	23	*/
	24
	25	#include <linux/mm.h>
	26	#include <linux/io-mapping.h>
	27
c58305af CW	28
c58305af CW	29	#include "i915_drv.h"
67c430bb	30	#include "i915_mm.h"
c58305af	31
293837b9 LT	32	struct remap_pfn {
	33	struct mm_struct *mm;
	34	unsigned long pfn;
	35	pgprot_t prot;
	36
	37	struct sgt_iter sgt;
	38	resource_size_t iobase;
	39	};
c58305af	40
4e598fad AJ	41	#define use_dma(io) ((io) != -1)
4e598fad AJ	42
293837b9 LT	43	static inline unsigned long sgt_pfn(const struct remap_pfn *r)
	44	{
	45	if (use_dma(r->iobase))
	46	return (r->sgt.dma + r->sgt.curr + r->iobase) >> PAGE_SHIFT;
	47	else
	48	return r->sgt.pfn + (r->sgt.curr >> PAGE_SHIFT);
	49	}
	50
	51	static int remap_sg(pte_t pte, unsigned long addr, void data)
	52	{
	53	struct remap_pfn *r = data;
	54
	55	if (GEM_WARN_ON(!r->sgt.sgp))
	56	return -EINVAL;
	57
	58	/* Special PTE are not associated with any struct page */
	59	set_pte_at(r->mm, addr, pte,
	60	pte_mkspecial(pfn_pte(sgt_pfn(r), r->prot)));
	61	r->pfn++; /* track insertions in case we need to unwind later */
	62
	63	r->sgt.curr += PAGE_SIZE;
	64	if (r->sgt.curr >= r->sgt.max)
	65	r->sgt = __sgt_iter(__sg_next(r->sgt.sgp), use_dma(r->iobase));
	66
	67	return 0;
	68	}
	69
67c430bb SM	70	#define EXPECTED_FLAGS (VM_PFNMAP \| VM_DONTEXPAND \| VM_DONTDUMP)
	71
	72	#if IS_ENABLED(CONFIG_X86)
	73	static int remap_pfn(pte_t pte, unsigned long addr, void data)
	74	{
	75	struct remap_pfn *r = data;
	76
	77	/* Special PTE are not associated with any struct page */
	78	set_pte_at(r->mm, addr, pte, pte_mkspecial(pfn_pte(r->pfn, r->prot)));
	79	r->pfn++;
	80
	81	return 0;
	82	}
	83
0e4fe0c9 MA	84	/**
	85	* remap_io_mapping - remap an IO mapping to userspace
	86	* @vma: user vma to map to
	87	* @addr: target user address to start at
	88	* @pfn: physical address of kernel memory
	89	* @size: size of map area
	90	* @iomap: the source io_mapping
	91	*
	92	* Note: this is only safe if the mm semaphore is held when called.
	93	*/
	94	int remap_io_mapping(struct vm_area_struct *vma,
	95	unsigned long addr, unsigned long pfn, unsigned long size,
	96	struct io_mapping *iomap)
	97	{
	98	struct remap_pfn r;
	99	int err;
	100
0e4fe0c9 MA	101	GEM_BUG_ON((vma->vm_flags & EXPECTED_FLAGS) != EXPECTED_FLAGS);
	102
	103	/* We rely on prevalidation of the io-mapping to skip track_pfn(). */
	104	r.mm = vma->vm_mm;
	105	r.pfn = pfn;
	106	r.prot = __pgprot((pgprot_val(iomap->prot) & _PAGE_CACHE_MASK) \|
	107	(pgprot_val(vma->vm_page_prot) & ~_PAGE_CACHE_MASK));
	108
	109	err = apply_to_page_range(r.mm, addr, size, remap_pfn, &r);
	110	if (unlikely(err)) {
	111	zap_vma_ptes(vma, addr, (r.pfn - pfn) << PAGE_SHIFT);
	112	return err;
	113	}
	114
	115	return 0;
	116	}
67c430bb	117	#endif
293837b9	118
1764b992	119	/**
4e598fad	120	* remap_io_sg - remap an IO mapping to userspace
1764b992 AJ	121	* @vma: user vma to map to
	122	* @addr: target user address to start at
	123	* @size: size of map area
	124	* @sgl: Start sg entry
4e598fad	125	* @iobase: Use stored dma address offset by this address or pfn if -1
1764b992 AJ	126	*
	127	* Note: this is only safe if the mm semaphore is held when called.
	128	*/
4e598fad AJ	129	int remap_io_sg(struct vm_area_struct *vma,
	130	unsigned long addr, unsigned long size,
	131	struct scatterlist *sgl, resource_size_t iobase)
1764b992	132	{
293837b9 LT	133	struct remap_pfn r = {
	134	.mm = vma->vm_mm,
	135	.prot = vma->vm_page_prot,
	136	.sgt = __sgt_iter(sgl, use_dma(iobase)),
	137	.iobase = iobase,
	138	};
1764b992 AJ	139	int err;
	140
	141	/* We rely on prevalidation of the io-mapping to skip track_pfn(). */
	142	GEM_BUG_ON((vma->vm_flags & EXPECTED_FLAGS) != EXPECTED_FLAGS);
	143
4e598fad AJ	144	if (!use_dma(iobase))
	145	flush_cache_range(vma, addr, size);
	146
293837b9 LT	147	err = apply_to_page_range(r.mm, addr, size, remap_sg, &r);
	148	if (unlikely(err)) {
	149	zap_vma_ptes(vma, addr, r.pfn << PAGE_SHIFT);
	150	return err;
	151	}
	152
	153	return 0;
1764b992	154	}