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 = phys_to_mach.rb_node;
66 struct xen_p2m_entry *entry;
67 unsigned long irqflags;
68
69 read_lock_irqsave(&p2m_lock, irqflags);
70 while (n) {
71 entry = rb_entry(n, struct xen_p2m_entry, rbnode_phys);
72 if (entry->pfn <= pfn &&
73 entry->pfn + entry->nr_pages > pfn) {
74 unsigned long mfn = entry->mfn + (pfn - entry->pfn);
75 read_unlock_irqrestore(&p2m_lock, irqflags);
76 return mfn;
77 }
78 if (pfn < entry->pfn)
79 n = n->rb_left;
80 else
81 n = n->rb_right;
82 }
83 read_unlock_irqrestore(&p2m_lock, irqflags);
84
85 return INVALID_P2M_ENTRY;
86 }
87 EXPORT_SYMBOL_GPL(__pfn_to_mfn);
88
set_foreign_p2m_mapping(struct gnttab_map_grant_ref * map_ops,struct gnttab_map_grant_ref * kmap_ops,struct page ** pages,unsigned int count)89 int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
90 struct gnttab_map_grant_ref *kmap_ops,
91 struct page **pages, unsigned int count)
92 {
93 int i;
94
95 for (i = 0; i < count; i++) {
96 if (map_ops[i].status)
97 continue;
98 set_phys_to_machine(map_ops[i].host_addr >> XEN_PAGE_SHIFT,
99 map_ops[i].dev_bus_addr >> XEN_PAGE_SHIFT);
100 }
101
102 return 0;
103 }
104 EXPORT_SYMBOL_GPL(set_foreign_p2m_mapping);
105
clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref * unmap_ops,struct gnttab_unmap_grant_ref * kunmap_ops,struct page ** pages,unsigned int count)106 int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
107 struct gnttab_unmap_grant_ref *kunmap_ops,
108 struct page **pages, unsigned int count)
109 {
110 int i;
111
112 for (i = 0; i < count; i++) {
113 set_phys_to_machine(unmap_ops[i].host_addr >> XEN_PAGE_SHIFT,
114 INVALID_P2M_ENTRY);
115 }
116
117 return 0;
118 }
119 EXPORT_SYMBOL_GPL(clear_foreign_p2m_mapping);
120
__set_phys_to_machine_multi(unsigned long pfn,unsigned long mfn,unsigned long nr_pages)121 bool __set_phys_to_machine_multi(unsigned long pfn,
122 unsigned long mfn, unsigned long nr_pages)
123 {
124 int rc;
125 unsigned long irqflags;
126 struct xen_p2m_entry *p2m_entry;
127 struct rb_node *n = phys_to_mach.rb_node;
128
129 if (mfn == INVALID_P2M_ENTRY) {
130 write_lock_irqsave(&p2m_lock, irqflags);
131 while (n) {
132 p2m_entry = rb_entry(n, struct xen_p2m_entry, rbnode_phys);
133 if (p2m_entry->pfn <= pfn &&
134 p2m_entry->pfn + p2m_entry->nr_pages > pfn) {
135 rb_erase(&p2m_entry->rbnode_phys, &phys_to_mach);
136 write_unlock_irqrestore(&p2m_lock, irqflags);
137 kfree(p2m_entry);
138 return true;
139 }
140 if (pfn < p2m_entry->pfn)
141 n = n->rb_left;
142 else
143 n = n->rb_right;
144 }
145 write_unlock_irqrestore(&p2m_lock, irqflags);
146 return true;
147 }
148
149 p2m_entry = kzalloc(sizeof(*p2m_entry), GFP_NOWAIT);
150 if (!p2m_entry)
151 return false;
152
153 p2m_entry->pfn = pfn;
154 p2m_entry->nr_pages = nr_pages;
155 p2m_entry->mfn = mfn;
156
157 write_lock_irqsave(&p2m_lock, irqflags);
158 rc = xen_add_phys_to_mach_entry(p2m_entry);
159 if (rc < 0) {
160 write_unlock_irqrestore(&p2m_lock, irqflags);
161 kfree(p2m_entry);
162 return false;
163 }
164 write_unlock_irqrestore(&p2m_lock, irqflags);
165 return true;
166 }
167 EXPORT_SYMBOL_GPL(__set_phys_to_machine_multi);
168
__set_phys_to_machine(unsigned long pfn,unsigned long mfn)169 bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn)
170 {
171 return __set_phys_to_machine_multi(pfn, mfn, 1);
172 }
173 EXPORT_SYMBOL_GPL(__set_phys_to_machine);
174
p2m_init(void)175 static int p2m_init(void)
176 {
177 rwlock_init(&p2m_lock);
178 return 0;
179 }
180 arch_initcall(p2m_init);
181
