xref: /dflybsd-src/sys/dev/drm/i915/i915_mm.c (revision 1e12ee3baa16120663cde9c6c4c8e92b69b00794)
1*1e12ee3bSFrançois Tigeot /*
2*1e12ee3bSFrançois Tigeot  * Copyright © 2014 Intel Corporation
3*1e12ee3bSFrançois Tigeot  *
4*1e12ee3bSFrançois Tigeot  * Permission is hereby granted, free of charge, to any person obtaining a
5*1e12ee3bSFrançois Tigeot  * copy of this software and associated documentation files (the "Software"),
6*1e12ee3bSFrançois Tigeot  * to deal in the Software without restriction, including without limitation
7*1e12ee3bSFrançois Tigeot  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8*1e12ee3bSFrançois Tigeot  * and/or sell copies of the Software, and to permit persons to whom the
9*1e12ee3bSFrançois Tigeot  * Software is furnished to do so, subject to the following conditions:
10*1e12ee3bSFrançois Tigeot  *
11*1e12ee3bSFrançois Tigeot  * The above copyright notice and this permission notice (including the next
12*1e12ee3bSFrançois Tigeot  * paragraph) shall be included in all copies or substantial portions of the
13*1e12ee3bSFrançois Tigeot  * Software.
14*1e12ee3bSFrançois Tigeot  *
15*1e12ee3bSFrançois Tigeot  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16*1e12ee3bSFrançois Tigeot  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17*1e12ee3bSFrançois Tigeot  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18*1e12ee3bSFrançois Tigeot  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19*1e12ee3bSFrançois Tigeot  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20*1e12ee3bSFrançois Tigeot  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21*1e12ee3bSFrançois Tigeot  * IN THE SOFTWARE.
22*1e12ee3bSFrançois Tigeot  *
23*1e12ee3bSFrançois Tigeot  */
24*1e12ee3bSFrançois Tigeot 
25*1e12ee3bSFrançois Tigeot #include <linux/mm.h>
26*1e12ee3bSFrançois Tigeot #include <linux/io-mapping.h>
27*1e12ee3bSFrançois Tigeot 
28*1e12ee3bSFrançois Tigeot #include <asm/pgtable.h>
29*1e12ee3bSFrançois Tigeot 
30*1e12ee3bSFrançois Tigeot #include "i915_drv.h"
31*1e12ee3bSFrançois Tigeot 
32*1e12ee3bSFrançois Tigeot struct remap_pfn {
33*1e12ee3bSFrançois Tigeot 	struct mm_struct *mm;
34*1e12ee3bSFrançois Tigeot 	unsigned long pfn;
35*1e12ee3bSFrançois Tigeot 	pgprot_t prot;
36*1e12ee3bSFrançois Tigeot };
37*1e12ee3bSFrançois Tigeot 
38*1e12ee3bSFrançois Tigeot #if 0
39*1e12ee3bSFrançois Tigeot static int remap_pfn(pte_t *pte, pgtable_t token,
40*1e12ee3bSFrançois Tigeot 		     unsigned long addr, void *data)
41*1e12ee3bSFrançois Tigeot {
42*1e12ee3bSFrançois Tigeot 	struct remap_pfn *r = data;
43*1e12ee3bSFrançois Tigeot 
44*1e12ee3bSFrançois Tigeot 	/* Special PTE are not associated with any struct page */
45*1e12ee3bSFrançois Tigeot 	set_pte_at(r->mm, addr, pte, pte_mkspecial(pfn_pte(r->pfn, r->prot)));
46*1e12ee3bSFrançois Tigeot 	r->pfn++;
47*1e12ee3bSFrançois Tigeot 
48*1e12ee3bSFrançois Tigeot 	return 0;
49*1e12ee3bSFrançois Tigeot }
50*1e12ee3bSFrançois Tigeot 
51*1e12ee3bSFrançois Tigeot /**
52*1e12ee3bSFrançois Tigeot  * remap_io_mapping - remap an IO mapping to userspace
53*1e12ee3bSFrançois Tigeot  * @vma: user vma to map to
54*1e12ee3bSFrançois Tigeot  * @addr: target user address to start at
55*1e12ee3bSFrançois Tigeot  * @pfn: physical address of kernel memory
56*1e12ee3bSFrançois Tigeot  * @size: size of map area
57*1e12ee3bSFrançois Tigeot  * @iomap: the source io_mapping
58*1e12ee3bSFrançois Tigeot  *
59*1e12ee3bSFrançois Tigeot  *  Note: this is only safe if the mm semaphore is held when called.
60*1e12ee3bSFrançois Tigeot  */
61*1e12ee3bSFrançois Tigeot int remap_io_mapping(struct vm_area_struct *vma,
62*1e12ee3bSFrançois Tigeot 		     unsigned long addr, unsigned long pfn, unsigned long size,
63*1e12ee3bSFrançois Tigeot 		     struct io_mapping *iomap)
64*1e12ee3bSFrançois Tigeot {
65*1e12ee3bSFrançois Tigeot 	struct remap_pfn r;
66*1e12ee3bSFrançois Tigeot 	int err;
67*1e12ee3bSFrançois Tigeot 
68*1e12ee3bSFrançois Tigeot 	GEM_BUG_ON((vma->vm_flags &
69*1e12ee3bSFrançois Tigeot 		    (VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP)) !=
70*1e12ee3bSFrançois Tigeot 		   (VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP));
71*1e12ee3bSFrançois Tigeot 
72*1e12ee3bSFrançois Tigeot 	/* We rely on prevalidation of the io-mapping to skip track_pfn(). */
73*1e12ee3bSFrançois Tigeot 	r.mm = vma->vm_mm;
74*1e12ee3bSFrançois Tigeot 	r.pfn = pfn;
75*1e12ee3bSFrançois Tigeot 	r.prot = __pgprot((pgprot_val(iomap->prot) & _PAGE_CACHE_MASK) |
76*1e12ee3bSFrançois Tigeot 			  (pgprot_val(vma->vm_page_prot) & ~_PAGE_CACHE_MASK));
77*1e12ee3bSFrançois Tigeot 
78*1e12ee3bSFrançois Tigeot 	err = apply_to_page_range(r.mm, addr, size, remap_pfn, &r);
79*1e12ee3bSFrançois Tigeot 	if (unlikely(err)) {
80*1e12ee3bSFrançois Tigeot 		zap_vma_ptes(vma, addr, (r.pfn - pfn) << PAGE_SHIFT);
81*1e12ee3bSFrançois Tigeot 		return err;
82*1e12ee3bSFrançois Tigeot 	}
83*1e12ee3bSFrançois Tigeot 
84*1e12ee3bSFrançois Tigeot 	return 0;
85*1e12ee3bSFrançois Tigeot }
86*1e12ee3bSFrançois Tigeot #endif
87