arch: syscalls: simplify uapi/kapi directory creation
[linux-2.6-microblaze.git] / arch / arm / xen / p2m.c
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
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
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
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
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
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
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
203 static int p2m_init(void)
204 {
205         rwlock_init(&p2m_lock);
206         return 0;
207 }
208 arch_initcall(p2m_init);