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1// SPDX-License-Identifier: GPL-2.0 OR MIT
2/******************************************************************************
3 * grant_table.c
4 * x86 specific part
5 *
6 * Granting foreign access to our memory reservation.
7 *
8 * Copyright (c) 2005-2006, Christopher Clark
9 * Copyright (c) 2004-2005, K A Fraser
10 * Copyright (c) 2008 Isaku Yamahata <yamahata at valinux co jp>
11 * VA Linux Systems Japan. Split out x86 specific part.
12 */
13
14#include <linux/sched.h>
15#include <linux/mm.h>
16#include <linux/slab.h>
17#include <linux/vmalloc.h>
18
19#include <xen/interface/xen.h>
20#include <xen/page.h>
21#include <xen/grant_table.h>
22#include <xen/xen.h>
23
24
25static struct gnttab_vm_area {
26 struct vm_struct *area;
27 pte_t **ptes;
28 int idx;
29} gnttab_shared_vm_area, gnttab_status_vm_area;
30
31int arch_gnttab_map_shared(unsigned long *frames, unsigned long nr_gframes,
32 unsigned long max_nr_gframes,
33 void **__shared)
34{
35 void *shared = *__shared;
36 unsigned long addr;
37 unsigned long i;
38
39 if (shared == NULL)
40 *__shared = shared = gnttab_shared_vm_area.area->addr;
41
42 addr = (unsigned long)shared;
43
44 for (i = 0; i < nr_gframes; i++) {
45 set_pte_at(&init_mm, addr, gnttab_shared_vm_area.ptes[i],
46 mfn_pte(frames[i], PAGE_KERNEL));
47 addr += PAGE_SIZE;
48 }
49
50 return 0;
51}
52
53int arch_gnttab_map_status(uint64_t *frames, unsigned long nr_gframes,
54 unsigned long max_nr_gframes,
55 grant_status_t **__shared)
56{
57 grant_status_t *shared = *__shared;
58 unsigned long addr;
59 unsigned long i;
60
61 if (shared == NULL)
62 *__shared = shared = gnttab_status_vm_area.area->addr;
63
64 addr = (unsigned long)shared;
65
66 for (i = 0; i < nr_gframes; i++) {
67 set_pte_at(&init_mm, addr, gnttab_status_vm_area.ptes[i],
68 mfn_pte(frames[i], PAGE_KERNEL));
69 addr += PAGE_SIZE;
70 }
71
72 return 0;
73}
74
75void arch_gnttab_unmap(void *shared, unsigned long nr_gframes)
76{
77 pte_t **ptes;
78 unsigned long addr;
79 unsigned long i;
80
81 if (shared == gnttab_status_vm_area.area->addr)
82 ptes = gnttab_status_vm_area.ptes;
83 else
84 ptes = gnttab_shared_vm_area.ptes;
85
86 addr = (unsigned long)shared;
87
88 for (i = 0; i < nr_gframes; i++) {
89 set_pte_at(&init_mm, addr, ptes[i], __pte(0));
90 addr += PAGE_SIZE;
91 }
92}
93
94static int gnttab_apply(pte_t *pte, unsigned long addr, void *data)
95{
96 struct gnttab_vm_area *area = data;
97
98 area->ptes[area->idx++] = pte;
99 return 0;
100}
101
102static int arch_gnttab_valloc(struct gnttab_vm_area *area, unsigned nr_frames)
103{
104 area->ptes = kmalloc_array(nr_frames, sizeof(*area->ptes), GFP_KERNEL);
105 if (area->ptes == NULL)
106 return -ENOMEM;
107 area->area = get_vm_area(PAGE_SIZE * nr_frames, VM_IOREMAP);
108 if (!area->area)
109 goto out_free_ptes;
110 if (apply_to_page_range(&init_mm, (unsigned long)area->area->addr,
111 PAGE_SIZE * nr_frames, gnttab_apply, area))
112 goto out_free_vm_area;
113 return 0;
114out_free_vm_area:
115 free_vm_area(area->area);
116out_free_ptes:
117 kfree(area->ptes);
118 return -ENOMEM;
119}
120
121static void arch_gnttab_vfree(struct gnttab_vm_area *area)
122{
123 free_vm_area(area->area);
124 kfree(area->ptes);
125}
126
127int arch_gnttab_init(unsigned long nr_shared, unsigned long nr_status)
128{
129 int ret;
130
131 if (!xen_pv_domain())
132 return 0;
133
134 ret = arch_gnttab_valloc(&gnttab_shared_vm_area, nr_shared);
135 if (ret < 0)
136 return ret;
137
138 /*
139 * Always allocate the space for the status frames in case
140 * we're migrated to a host with V2 support.
141 */
142 ret = arch_gnttab_valloc(&gnttab_status_vm_area, nr_status);
143 if (ret < 0)
144 goto err;
145
146 return 0;
147err:
148 arch_gnttab_vfree(&gnttab_shared_vm_area);
149 return -ENOMEM;
150}
151
152#ifdef CONFIG_XEN_PVH
153#include <xen/events.h>
154#include <xen/xen-ops.h>
155static int __init xen_pvh_gnttab_setup(void)
156{
157 if (!xen_pvh_domain())
158 return -ENODEV;
159
160 xen_auto_xlat_grant_frames.count = gnttab_max_grant_frames();
161
162 return xen_xlate_map_ballooned_pages(&xen_auto_xlat_grant_frames.pfn,
163 &xen_auto_xlat_grant_frames.vaddr,
164 xen_auto_xlat_grant_frames.count);
165}
166/* Call it _before_ __gnttab_init as we need to initialize the
167 * xen_auto_xlat_grant_frames first. */
168core_initcall(xen_pvh_gnttab_setup);
169#endif
1/******************************************************************************
2 * grant_table.c
3 * x86 specific part
4 *
5 * Granting foreign access to our memory reservation.
6 *
7 * Copyright (c) 2005-2006, Christopher Clark
8 * Copyright (c) 2004-2005, K A Fraser
9 * Copyright (c) 2008 Isaku Yamahata <yamahata at valinux co jp>
10 * VA Linux Systems Japan. Split out x86 specific part.
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License version 2
14 * as published by the Free Software Foundation; or, when distributed
15 * separately from the Linux kernel or incorporated into other
16 * software packages, subject to the following license:
17 *
18 * Permission is hereby granted, free of charge, to any person obtaining a copy
19 * of this source file (the "Software"), to deal in the Software without
20 * restriction, including without limitation the rights to use, copy, modify,
21 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
22 * and to permit persons to whom the Software is furnished to do so, subject to
23 * the following conditions:
24 *
25 * The above copyright notice and this permission notice shall be included in
26 * all copies or substantial portions of the Software.
27 *
28 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
29 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
30 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
31 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
32 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
33 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
34 * IN THE SOFTWARE.
35 */
36
37#include <linux/sched.h>
38#include <linux/mm.h>
39#include <linux/vmalloc.h>
40
41#include <xen/interface/xen.h>
42#include <xen/page.h>
43#include <xen/grant_table.h>
44
45#include <asm/pgtable.h>
46
47static int map_pte_fn(pte_t *pte, struct page *pmd_page,
48 unsigned long addr, void *data)
49{
50 unsigned long **frames = (unsigned long **)data;
51
52 set_pte_at(&init_mm, addr, pte, mfn_pte((*frames)[0], PAGE_KERNEL));
53 (*frames)++;
54 return 0;
55}
56
57/*
58 * This function is used to map shared frames to store grant status. It is
59 * different from map_pte_fn above, the frames type here is uint64_t.
60 */
61static int map_pte_fn_status(pte_t *pte, struct page *pmd_page,
62 unsigned long addr, void *data)
63{
64 uint64_t **frames = (uint64_t **)data;
65
66 set_pte_at(&init_mm, addr, pte, mfn_pte((*frames)[0], PAGE_KERNEL));
67 (*frames)++;
68 return 0;
69}
70
71static int unmap_pte_fn(pte_t *pte, struct page *pmd_page,
72 unsigned long addr, void *data)
73{
74
75 set_pte_at(&init_mm, addr, pte, __pte(0));
76 return 0;
77}
78
79int arch_gnttab_map_shared(unsigned long *frames, unsigned long nr_gframes,
80 unsigned long max_nr_gframes,
81 void **__shared)
82{
83 int rc;
84 void *shared = *__shared;
85
86 if (shared == NULL) {
87 struct vm_struct *area =
88 alloc_vm_area(PAGE_SIZE * max_nr_gframes, NULL);
89 BUG_ON(area == NULL);
90 shared = area->addr;
91 *__shared = shared;
92 }
93
94 rc = apply_to_page_range(&init_mm, (unsigned long)shared,
95 PAGE_SIZE * nr_gframes,
96 map_pte_fn, &frames);
97 return rc;
98}
99
100int arch_gnttab_map_status(uint64_t *frames, unsigned long nr_gframes,
101 unsigned long max_nr_gframes,
102 grant_status_t **__shared)
103{
104 int rc;
105 grant_status_t *shared = *__shared;
106
107 if (shared == NULL) {
108 /* No need to pass in PTE as we are going to do it
109 * in apply_to_page_range anyhow. */
110 struct vm_struct *area =
111 alloc_vm_area(PAGE_SIZE * max_nr_gframes, NULL);
112 BUG_ON(area == NULL);
113 shared = area->addr;
114 *__shared = shared;
115 }
116
117 rc = apply_to_page_range(&init_mm, (unsigned long)shared,
118 PAGE_SIZE * nr_gframes,
119 map_pte_fn_status, &frames);
120 return rc;
121}
122
123void arch_gnttab_unmap(void *shared, unsigned long nr_gframes)
124{
125 apply_to_page_range(&init_mm, (unsigned long)shared,
126 PAGE_SIZE * nr_gframes, unmap_pte_fn, NULL);
127}