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/page.h>
15 #include <xen/swiotlb-xen.h>
16
17 #include <asm/cacheflush.h>
18 #include <asm/xen/hypercall.h>
19 #include <asm/xen/interface.h>
20
21 struct xen_p2m_entry {
22 unsigned long pfn;
23 unsigned long mfn;
24 unsigned long nr_pages;
25 struct rb_node rbnode_phys;
26 };
27
28 static rwlock_t p2m_lock;
29 struct rb_root phys_to_mach = RB_ROOT;
30 EXPORT_SYMBOL_GPL(phys_to_mach);
31
xen_add_phys_to_mach_entry(struct xen_p2m_entry *new)32 static int xen_add_phys_to_mach_entry(struct xen_p2m_entry *new)
33 {
34 struct rb_node **link = &phys_to_mach.rb_node;
35 struct rb_node *parent = NULL;
36 struct xen_p2m_entry *entry;
37 int rc = 0;
38
39 while (*link) {
40 parent = *link;
41 entry = rb_entry(parent, struct xen_p2m_entry, rbnode_phys);
42
43 if (new->pfn == entry->pfn)
44 goto err_out;
45
46 if (new->pfn < entry->pfn)
47 link = &(*link)->rb_left;
48 else
49 link = &(*link)->rb_right;
50 }
51 rb_link_node(&new->rbnode_phys, parent, link);
52 rb_insert_color(&new->rbnode_phys, &phys_to_mach);
53 goto out;
54
55 err_out:
56 rc = -EINVAL;
57 pr_warn("%s: cannot add pfn=%pa -> mfn=%pa: pfn=%pa -> mfn=%pa already exists\n",
58 __func__, &new->pfn, &new->mfn, &entry->pfn, &entry->mfn);
59 out:
60 return rc;
61 }
62
__pfn_to_mfn(unsigned long pfn)63 unsigned long __pfn_to_mfn(unsigned long pfn)
64 {
65 struct rb_node *n;
66 struct xen_p2m_entry *entry;
67 unsigned long irqflags;
68
69 read_lock_irqsave(&p2m_lock, irqflags);
70 n = phys_to_mach.rb_node;
71 while (n) {
72 entry = rb_entry(n, struct xen_p2m_entry, rbnode_phys);
73 if (entry->pfn <= pfn &&
74 entry->pfn + entry->nr_pages > pfn) {
75 unsigned long mfn = entry->mfn + (pfn - entry->pfn);
76 read_unlock_irqrestore(&p2m_lock, irqflags);
77 return mfn;
78 }
79 if (pfn < entry->pfn)
80 n = n->rb_left;
81 else
82 n = n->rb_right;
83 }
84 read_unlock_irqrestore(&p2m_lock, irqflags);
85
86 return INVALID_P2M_ENTRY;
87 }
88 EXPORT_SYMBOL_GPL(__pfn_to_mfn);
89
set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, struct gnttab_map_grant_ref *kmap_ops, struct page **pages, unsigned int count)90 int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
91 struct gnttab_map_grant_ref *kmap_ops,
92 struct page **pages, unsigned int count)
93 {
94 int i;
95
96 for (i = 0; i < count; i++) {
97 struct gnttab_unmap_grant_ref unmap;
98 int rc;
99
100 if (map_ops[i].status)
101 continue;
102 if (likely(set_phys_to_machine(map_ops[i].host_addr >> XEN_PAGE_SHIFT,
103 map_ops[i].dev_bus_addr >> XEN_PAGE_SHIFT)))
104 continue;
105
106 /*
107 * Signal an error for this slot. This in turn requires
108 * immediate unmapping.
109 */
110 map_ops[i].status = GNTST_general_error;
111 unmap.host_addr = map_ops[i].host_addr,
112 unmap.handle = map_ops[i].handle;
113 map_ops[i].handle = ~0;
114 if (map_ops[i].flags & GNTMAP_device_map)
115 unmap.dev_bus_addr = map_ops[i].dev_bus_addr;
116 else
117 unmap.dev_bus_addr = 0;
118
119 /*
120 * Pre-populate the status field, to be recognizable in
121 * the log message below.
122 */
123 unmap.status = 1;
124
125 rc = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref,
126 &unmap, 1);
127 if (rc || unmap.status != GNTST_okay)
128 pr_err_once("gnttab unmap failed: rc=%d st=%d\n",
129 rc, unmap.status);
130 }
131
132 return 0;
133 }
134 EXPORT_SYMBOL_GPL(set_foreign_p2m_mapping);
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 EXPORT_SYMBOL_GPL(clear_foreign_p2m_mapping);
150
__set_phys_to_machine_multi(unsigned long pfn, unsigned long mfn, unsigned long nr_pages)151 bool __set_phys_to_machine_multi(unsigned long pfn,
152 unsigned long mfn, unsigned long nr_pages)
153 {
154 int rc;
155 unsigned long irqflags;
156 struct xen_p2m_entry *p2m_entry;
157 struct rb_node *n;
158
159 if (mfn == INVALID_P2M_ENTRY) {
160 write_lock_irqsave(&p2m_lock, irqflags);
161 n = phys_to_mach.rb_node;
162 while (n) {
163 p2m_entry = rb_entry(n, struct xen_p2m_entry, rbnode_phys);
164 if (p2m_entry->pfn <= pfn &&
165 p2m_entry->pfn + p2m_entry->nr_pages > pfn) {
166 rb_erase(&p2m_entry->rbnode_phys, &phys_to_mach);
167 write_unlock_irqrestore(&p2m_lock, irqflags);
168 kfree(p2m_entry);
169 return true;
170 }
171 if (pfn < p2m_entry->pfn)
172 n = n->rb_left;
173 else
174 n = n->rb_right;
175 }
176 write_unlock_irqrestore(&p2m_lock, irqflags);
177 return true;
178 }
179
180 p2m_entry = kzalloc(sizeof(*p2m_entry), GFP_NOWAIT);
181 if (!p2m_entry)
182 return false;
183
184 p2m_entry->pfn = pfn;
185 p2m_entry->nr_pages = nr_pages;
186 p2m_entry->mfn = mfn;
187
188 write_lock_irqsave(&p2m_lock, irqflags);
189 rc = xen_add_phys_to_mach_entry(p2m_entry);
190 if (rc < 0) {
191 write_unlock_irqrestore(&p2m_lock, irqflags);
192 kfree(p2m_entry);
193 return false;
194 }
195 write_unlock_irqrestore(&p2m_lock, irqflags);
196 return true;
197 }
198 EXPORT_SYMBOL_GPL(__set_phys_to_machine_multi);
199
__set_phys_to_machine(unsigned long pfn, unsigned long mfn)200 bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn)
201 {
202 return __set_phys_to_machine_multi(pfn, mfn, 1);
203 }
204 EXPORT_SYMBOL_GPL(__set_phys_to_machine);
205
p2m_init(void)206 static int p2m_init(void)
207 {
208 rwlock_init(&p2m_lock);
209 return 0;
210 }
211 arch_initcall(p2m_init);
212