1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
|
// SPDX-License-Identifier: GPL-2.0
#include <linux/errno.h>
#include <linux/gfp.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/memremap.h>
#include <linux/slab.h>
#include <asm/page.h>
#include <xen/page.h>
#include <xen/xen.h>
static DEFINE_MUTEX(list_lock);
static struct page *page_list;
static unsigned int list_count;
static int fill_list(unsigned int nr_pages)
{
struct dev_pagemap *pgmap;
struct resource *res;
void *vaddr;
unsigned int i, alloc_pages = round_up(nr_pages, PAGES_PER_SECTION);
int ret = -ENOMEM;
res = kzalloc(sizeof(*res), GFP_KERNEL);
if (!res)
return -ENOMEM;
res->name = "Xen scratch";
res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
ret = allocate_resource(&iomem_resource, res,
alloc_pages * PAGE_SIZE, 0, -1,
PAGES_PER_SECTION * PAGE_SIZE, NULL, NULL);
if (ret < 0) {
pr_err("Cannot allocate new IOMEM resource\n");
goto err_resource;
}
pgmap = kzalloc(sizeof(*pgmap), GFP_KERNEL);
if (!pgmap) {
ret = -ENOMEM;
goto err_pgmap;
}
pgmap->type = MEMORY_DEVICE_GENERIC;
pgmap->range = (struct range) {
.start = res->start,
.end = res->end,
};
pgmap->nr_range = 1;
pgmap->owner = res;
#ifdef CONFIG_XEN_HAVE_PVMMU
/*
* memremap will build page tables for the new memory so
* the p2m must contain invalid entries so the correct
* non-present PTEs will be written.
*
* If a failure occurs, the original (identity) p2m entries
* are not restored since this region is now known not to
* conflict with any devices.
*/
if (!xen_feature(XENFEAT_auto_translated_physmap)) {
xen_pfn_t pfn = PFN_DOWN(res->start);
for (i = 0; i < alloc_pages; i++) {
if (!set_phys_to_machine(pfn + i, INVALID_P2M_ENTRY)) {
pr_warn("set_phys_to_machine() failed, no memory added\n");
ret = -ENOMEM;
goto err_memremap;
}
}
}
#endif
vaddr = memremap_pages(pgmap, NUMA_NO_NODE);
if (IS_ERR(vaddr)) {
pr_err("Cannot remap memory range\n");
ret = PTR_ERR(vaddr);
goto err_memremap;
}
for (i = 0; i < alloc_pages; i++) {
struct page *pg = virt_to_page(vaddr + PAGE_SIZE * i);
BUG_ON(!virt_addr_valid(vaddr + PAGE_SIZE * i));
pg->zone_device_data = page_list;
page_list = pg;
list_count++;
}
return 0;
err_memremap:
kfree(pgmap);
err_pgmap:
release_resource(res);
err_resource:
kfree(res);
return ret;
}
/**
* xen_alloc_unpopulated_pages - alloc unpopulated pages
* @nr_pages: Number of pages
* @pages: pages returned
* @return 0 on success, error otherwise
*/
int xen_alloc_unpopulated_pages(unsigned int nr_pages, struct page **pages)
{
unsigned int i;
int ret = 0;
mutex_lock(&list_lock);
if (list_count < nr_pages) {
ret = fill_list(nr_pages - list_count);
if (ret)
goto out;
}
for (i = 0; i < nr_pages; i++) {
struct page *pg = page_list;
BUG_ON(!pg);
page_list = pg->zone_device_data;
list_count--;
pages[i] = pg;
#ifdef CONFIG_XEN_HAVE_PVMMU
if (!xen_feature(XENFEAT_auto_translated_physmap)) {
ret = xen_alloc_p2m_entry(page_to_pfn(pg));
if (ret < 0) {
unsigned int j;
for (j = 0; j <= i; j++) {
pages[j]->zone_device_data = page_list;
page_list = pages[j];
list_count++;
}
goto out;
}
}
#endif
}
out:
mutex_unlock(&list_lock);
return ret;
}
EXPORT_SYMBOL(xen_alloc_unpopulated_pages);
/**
* xen_free_unpopulated_pages - return unpopulated pages
* @nr_pages: Number of pages
* @pages: pages to return
*/
void xen_free_unpopulated_pages(unsigned int nr_pages, struct page **pages)
{
unsigned int i;
mutex_lock(&list_lock);
for (i = 0; i < nr_pages; i++) {
pages[i]->zone_device_data = page_list;
page_list = pages[i];
list_count++;
}
mutex_unlock(&list_lock);
}
EXPORT_SYMBOL(xen_free_unpopulated_pages);
#ifdef CONFIG_XEN_PV
static int __init init(void)
{
unsigned int i;
if (!xen_domain())
return -ENODEV;
if (!xen_pv_domain())
return 0;
/*
* Initialize with pages from the extra memory regions (see
* arch/x86/xen/setup.c).
*/
for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
unsigned int j;
for (j = 0; j < xen_extra_mem[i].n_pfns; j++) {
struct page *pg =
pfn_to_page(xen_extra_mem[i].start_pfn + j);
pg->zone_device_data = page_list;
page_list = pg;
list_count++;
}
}
return 0;
}
subsys_initcall(init);
#endif
|
