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 = phys_to_mach.rb_node;
67 struct xen_p2m_entry *entry;
68 unsigned long irqflags;
69
70 read_lock_irqsave(&p2m_lock, irqflags);
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 = INVALID_GRANT_HANDLE;
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
clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref * unmap_ops,struct gnttab_unmap_grant_ref * kunmap_ops,struct page ** pages,unsigned int count)135 int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
136 struct gnttab_unmap_grant_ref *kunmap_ops,
137 struct page **pages, unsigned int count)
138 {
139 int i;
140
141 for (i = 0; i < count; i++) {
142 set_phys_to_machine(unmap_ops[i].host_addr >> XEN_PAGE_SHIFT,
143 INVALID_P2M_ENTRY);
144 }
145
146 return 0;
147 }
148
__set_phys_to_machine_multi(unsigned long pfn,unsigned long mfn,unsigned long nr_pages)149 bool __set_phys_to_machine_multi(unsigned long pfn,
150 unsigned long mfn, unsigned long nr_pages)
151 {
152 int rc;
153 unsigned long irqflags;
154 struct xen_p2m_entry *p2m_entry;
155 struct rb_node *n = phys_to_mach.rb_node;
156
157 if (mfn == INVALID_P2M_ENTRY) {
158 write_lock_irqsave(&p2m_lock, irqflags);
159 while (n) {
160 p2m_entry = rb_entry(n, struct xen_p2m_entry, rbnode_phys);
161 if (p2m_entry->pfn <= pfn &&
162 p2m_entry->pfn + p2m_entry->nr_pages > pfn) {
163 rb_erase(&p2m_entry->rbnode_phys, &phys_to_mach);
164 write_unlock_irqrestore(&p2m_lock, irqflags);
165 kfree(p2m_entry);
166 return true;
167 }
168 if (pfn < p2m_entry->pfn)
169 n = n->rb_left;
170 else
171 n = n->rb_right;
172 }
173 write_unlock_irqrestore(&p2m_lock, irqflags);
174 return true;
175 }
176
177 p2m_entry = kzalloc(sizeof(*p2m_entry), GFP_NOWAIT);
178 if (!p2m_entry)
179 return false;
180
181 p2m_entry->pfn = pfn;
182 p2m_entry->nr_pages = nr_pages;
183 p2m_entry->mfn = mfn;
184
185 write_lock_irqsave(&p2m_lock, irqflags);
186 rc = xen_add_phys_to_mach_entry(p2m_entry);
187 if (rc < 0) {
188 write_unlock_irqrestore(&p2m_lock, irqflags);
189 kfree(p2m_entry);
190 return false;
191 }
192 write_unlock_irqrestore(&p2m_lock, irqflags);
193 return true;
194 }
195 EXPORT_SYMBOL_GPL(__set_phys_to_machine_multi);
196
__set_phys_to_machine(unsigned long pfn,unsigned long mfn)197 bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn)
198 {
199 return __set_phys_to_machine_multi(pfn, mfn, 1);
200 }
201 EXPORT_SYMBOL_GPL(__set_phys_to_machine);
202
p2m_init(void)203 static int p2m_init(void)
204 {
205 rwlock_init(&p2m_lock);
206 return 0;
207 }
208 arch_initcall(p2m_init);
209