1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/memblock.h>
3 #include <linux/gfp.h>
4 #include <linux/export.h>
5 #include <linux/spinlock.h>
6 #include <linux/slab.h>
7 #include <linux/types.h>
8 #include <linux/dma-mapping.h>
9 #include <linux/vmalloc.h>
10 #include <linux/swiotlb.h>
11
12 #include <xen/xen.h>
13 #include <xen/interface/memory.h>
14 #include <xen/grant_table.h>
15 #include <xen/page.h>
16 #include <xen/swiotlb-xen.h>
17
18 #include <asm/cacheflush.h>
19 #include <asm/xen/hypercall.h>
20 #include <asm/xen/interface.h>
21
22 struct xen_p2m_entry {
23 unsigned long pfn;
24 unsigned long mfn;
25 unsigned long nr_pages;
26 struct rb_node rbnode_phys;
27 };
28
29 static rwlock_t p2m_lock;
30 struct rb_root phys_to_mach = RB_ROOT;
31 EXPORT_SYMBOL_GPL(phys_to_mach);
32
xen_add_phys_to_mach_entry(struct xen_p2m_entry * new)33 static int xen_add_phys_to_mach_entry(struct xen_p2m_entry *new)
34 {
35 struct rb_node **link = &phys_to_mach.rb_node;
36 struct rb_node *parent = NULL;
37 struct xen_p2m_entry *entry;
38 int rc = 0;
39
40 while (*link) {
41 parent = *link;
42 entry = rb_entry(parent, struct xen_p2m_entry, rbnode_phys);
43
44 if (new->pfn == entry->pfn)
45 goto err_out;
46
47 if (new->pfn < entry->pfn)
48 link = &(*link)->rb_left;
49 else
50 link = &(*link)->rb_right;
51 }
52 rb_link_node(&new->rbnode_phys, parent, link);
53 rb_insert_color(&new->rbnode_phys, &phys_to_mach);
54 goto out;
55
56 err_out:
57 rc = -EINVAL;
58 pr_warn("%s: cannot add pfn=%pa -> mfn=%pa: pfn=%pa -> mfn=%pa already exists\n",
59 __func__, &new->pfn, &new->mfn, &entry->pfn, &entry->mfn);
60 out:
61 return rc;
62 }
63
__pfn_to_mfn(unsigned long pfn)64 unsigned long __pfn_to_mfn(unsigned long pfn)
65 {
66 struct rb_node *n;
67 struct xen_p2m_entry *entry;
68 unsigned long irqflags;
69
70 read_lock_irqsave(&p2m_lock, irqflags);
71 n = phys_to_mach.rb_node;
72 while (n) {
73 entry = rb_entry(n, struct xen_p2m_entry, rbnode_phys);
74 if (entry->pfn <= pfn &&
75 entry->pfn + entry->nr_pages > pfn) {
76 unsigned long mfn = entry->mfn + (pfn - entry->pfn);
77 read_unlock_irqrestore(&p2m_lock, irqflags);
78 return mfn;
79 }
80 if (pfn < entry->pfn)
81 n = n->rb_left;
82 else
83 n = n->rb_right;
84 }
85 read_unlock_irqrestore(&p2m_lock, irqflags);
86
87 return INVALID_P2M_ENTRY;
88 }
89 EXPORT_SYMBOL_GPL(__pfn_to_mfn);
90
set_foreign_p2m_mapping(struct gnttab_map_grant_ref * map_ops,struct gnttab_map_grant_ref * kmap_ops,struct page ** pages,unsigned int count)91 int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
92 struct gnttab_map_grant_ref *kmap_ops,
93 struct page **pages, unsigned int count)
94 {
95 int i;
96
97 for (i = 0; i < count; i++) {
98 struct gnttab_unmap_grant_ref unmap;
99 int rc;
100
101 if (map_ops[i].status)
102 continue;
103 if (likely(set_phys_to_machine(map_ops[i].host_addr >> XEN_PAGE_SHIFT,
104 map_ops[i].dev_bus_addr >> XEN_PAGE_SHIFT)))
105 continue;
106
107 /*
108 * Signal an error for this slot. This in turn requires
109 * immediate unmapping.
110 */
111 map_ops[i].status = GNTST_general_error;
112 unmap.host_addr = map_ops[i].host_addr,
113 unmap.handle = map_ops[i].handle;
114 map_ops[i].handle = INVALID_GRANT_HANDLE;
115 if (map_ops[i].flags & GNTMAP_device_map)
116 unmap.dev_bus_addr = map_ops[i].dev_bus_addr;
117 else
118 unmap.dev_bus_addr = 0;
119
120 /*
121 * Pre-populate the status field, to be recognizable in
122 * the log message below.
123 */
124 unmap.status = 1;
125
126 rc = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref,
127 &unmap, 1);
128 if (rc || unmap.status != GNTST_okay)
129 pr_err_once("gnttab unmap failed: rc=%d st=%d\n",
130 rc, unmap.status);
131 }
132
133 return 0;
134 }
135
clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref * unmap_ops,struct gnttab_unmap_grant_ref * kunmap_ops,struct page ** pages,unsigned int count)136 int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
137 struct gnttab_unmap_grant_ref *kunmap_ops,
138 struct page **pages, unsigned int count)
139 {
140 int i;
141
142 for (i = 0; i < count; i++) {
143 set_phys_to_machine(unmap_ops[i].host_addr >> XEN_PAGE_SHIFT,
144 INVALID_P2M_ENTRY);
145 }
146
147 return 0;
148 }
149
__set_phys_to_machine_multi(unsigned long pfn,unsigned long mfn,unsigned long nr_pages)150 bool __set_phys_to_machine_multi(unsigned long pfn,
151 unsigned long mfn, unsigned long nr_pages)
152 {
153 int rc;
154 unsigned long irqflags;
155 struct xen_p2m_entry *p2m_entry;
156 struct rb_node *n;
157
158 if (mfn == INVALID_P2M_ENTRY) {
159 write_lock_irqsave(&p2m_lock, irqflags);
160 n = phys_to_mach.rb_node;
161 while (n) {
162 p2m_entry = rb_entry(n, struct xen_p2m_entry, rbnode_phys);
163 if (p2m_entry->pfn <= pfn &&
164 p2m_entry->pfn + p2m_entry->nr_pages > pfn) {
165 rb_erase(&p2m_entry->rbnode_phys, &phys_to_mach);
166 write_unlock_irqrestore(&p2m_lock, irqflags);
167 kfree(p2m_entry);
168 return true;
169 }
170 if (pfn < p2m_entry->pfn)
171 n = n->rb_left;
172 else
173 n = n->rb_right;
174 }
175 write_unlock_irqrestore(&p2m_lock, irqflags);
176 return true;
177 }
178
179 p2m_entry = kzalloc(sizeof(*p2m_entry), GFP_NOWAIT);
180 if (!p2m_entry)
181 return false;
182
183 p2m_entry->pfn = pfn;
184 p2m_entry->nr_pages = nr_pages;
185 p2m_entry->mfn = mfn;
186
187 write_lock_irqsave(&p2m_lock, irqflags);
188 rc = xen_add_phys_to_mach_entry(p2m_entry);
189 if (rc < 0) {
190 write_unlock_irqrestore(&p2m_lock, irqflags);
191 kfree(p2m_entry);
192 return false;
193 }
194 write_unlock_irqrestore(&p2m_lock, irqflags);
195 return true;
196 }
197 EXPORT_SYMBOL_GPL(__set_phys_to_machine_multi);
198
__set_phys_to_machine(unsigned long pfn,unsigned long mfn)199 bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn)
200 {
201 return __set_phys_to_machine_multi(pfn, mfn, 1);
202 }
203 EXPORT_SYMBOL_GPL(__set_phys_to_machine);
204
p2m_init(void)205 static int p2m_init(void)
206 {
207 rwlock_init(&p2m_lock);
208 return 0;
209 }
210 arch_initcall(p2m_init);
211
