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b15993fc IY |
1 | /* |
2 | * This program is free software; you can redistribute it and/or modify | |
3 | * it under the terms of the GNU General Public License as published by | |
4 | * the Free Software Foundation; either version 2 of the License, or | |
5 | * (at your option) any later version. | |
6 | * | |
7 | * This program is distributed in the hope that it will be useful, | |
8 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
9 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
10 | * GNU General Public License for more details. | |
11 | * | |
12 | * You should have received a copy of the GNU General Public License | |
13 | * along with this program; if not, write to the Free Software | |
14 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
15 | * | |
16 | * Copyright (C) IBM Corp. 2006 | |
17 | * | |
18 | * Authors: Hollis Blanchard <hollisb@us.ibm.com> | |
19 | */ | |
20 | ||
283c0972 JP |
21 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
22 | ||
b15993fc | 23 | #include <linux/mm.h> |
5a0e3ad6 | 24 | #include <linux/slab.h> |
b15993fc IY |
25 | #include <asm/page.h> |
26 | #include <xen/xencomm.h> | |
27 | #include <xen/interface/xen.h> | |
75909fd6 | 28 | #include <asm/xen/xencomm.h> /* for xencomm_is_phys_contiguous() */ |
b15993fc IY |
29 | |
30 | static int xencomm_init(struct xencomm_desc *desc, | |
31 | void *buffer, unsigned long bytes) | |
32 | { | |
33 | unsigned long recorded = 0; | |
34 | int i = 0; | |
35 | ||
36 | while ((recorded < bytes) && (i < desc->nr_addrs)) { | |
37 | unsigned long vaddr = (unsigned long)buffer + recorded; | |
38 | unsigned long paddr; | |
39 | int offset; | |
40 | int chunksz; | |
41 | ||
42 | offset = vaddr % PAGE_SIZE; /* handle partial pages */ | |
43 | chunksz = min(PAGE_SIZE - offset, bytes - recorded); | |
44 | ||
45 | paddr = xencomm_vtop(vaddr); | |
46 | if (paddr == ~0UL) { | |
47 | printk(KERN_DEBUG "%s: couldn't translate vaddr %lx\n", | |
48 | __func__, vaddr); | |
49 | return -EINVAL; | |
50 | } | |
51 | ||
52 | desc->address[i++] = paddr; | |
53 | recorded += chunksz; | |
54 | } | |
55 | ||
56 | if (recorded < bytes) { | |
57 | printk(KERN_DEBUG | |
58 | "%s: could only translate %ld of %ld bytes\n", | |
59 | __func__, recorded, bytes); | |
60 | return -ENOSPC; | |
61 | } | |
62 | ||
63 | /* mark remaining addresses invalid (just for safety) */ | |
64 | while (i < desc->nr_addrs) | |
65 | desc->address[i++] = XENCOMM_INVALID; | |
66 | ||
67 | desc->magic = XENCOMM_MAGIC; | |
68 | ||
69 | return 0; | |
70 | } | |
71 | ||
72 | static struct xencomm_desc *xencomm_alloc(gfp_t gfp_mask, | |
73 | void *buffer, unsigned long bytes) | |
74 | { | |
75 | struct xencomm_desc *desc; | |
76 | unsigned long buffer_ulong = (unsigned long)buffer; | |
77 | unsigned long start = buffer_ulong & PAGE_MASK; | |
78 | unsigned long end = (buffer_ulong + bytes) | ~PAGE_MASK; | |
79 | unsigned long nr_addrs = (end - start + 1) >> PAGE_SHIFT; | |
80 | unsigned long size = sizeof(*desc) + | |
81 | sizeof(desc->address[0]) * nr_addrs; | |
82 | ||
83 | /* | |
84 | * slab allocator returns at least sizeof(void*) aligned pointer. | |
85 | * When sizeof(*desc) > sizeof(void*), struct xencomm_desc might | |
86 | * cross page boundary. | |
87 | */ | |
88 | if (sizeof(*desc) > sizeof(void *)) { | |
89 | unsigned long order = get_order(size); | |
90 | desc = (struct xencomm_desc *)__get_free_pages(gfp_mask, | |
91 | order); | |
92 | if (desc == NULL) | |
93 | return NULL; | |
94 | ||
95 | desc->nr_addrs = | |
96 | ((PAGE_SIZE << order) - sizeof(struct xencomm_desc)) / | |
97 | sizeof(*desc->address); | |
98 | } else { | |
99 | desc = kmalloc(size, gfp_mask); | |
100 | if (desc == NULL) | |
101 | return NULL; | |
102 | ||
103 | desc->nr_addrs = nr_addrs; | |
104 | } | |
105 | return desc; | |
106 | } | |
107 | ||
108 | void xencomm_free(struct xencomm_handle *desc) | |
109 | { | |
110 | if (desc && !((ulong)desc & XENCOMM_INLINE_FLAG)) { | |
111 | struct xencomm_desc *desc__ = (struct xencomm_desc *)desc; | |
112 | if (sizeof(*desc__) > sizeof(void *)) { | |
113 | unsigned long size = sizeof(*desc__) + | |
114 | sizeof(desc__->address[0]) * desc__->nr_addrs; | |
115 | unsigned long order = get_order(size); | |
116 | free_pages((unsigned long)__va(desc), order); | |
117 | } else | |
118 | kfree(__va(desc)); | |
119 | } | |
120 | } | |
121 | ||
122 | static int xencomm_create(void *buffer, unsigned long bytes, | |
123 | struct xencomm_desc **ret, gfp_t gfp_mask) | |
124 | { | |
125 | struct xencomm_desc *desc; | |
126 | int rc; | |
127 | ||
128 | pr_debug("%s: %p[%ld]\n", __func__, buffer, bytes); | |
129 | ||
130 | if (bytes == 0) { | |
131 | /* don't create a descriptor; Xen recognizes NULL. */ | |
132 | BUG_ON(buffer != NULL); | |
133 | *ret = NULL; | |
134 | return 0; | |
135 | } | |
136 | ||
137 | BUG_ON(buffer == NULL); /* 'bytes' is non-zero */ | |
138 | ||
139 | desc = xencomm_alloc(gfp_mask, buffer, bytes); | |
140 | if (!desc) { | |
141 | printk(KERN_DEBUG "%s failure\n", "xencomm_alloc"); | |
142 | return -ENOMEM; | |
143 | } | |
144 | ||
145 | rc = xencomm_init(desc, buffer, bytes); | |
146 | if (rc) { | |
147 | printk(KERN_DEBUG "%s failure: %d\n", "xencomm_init", rc); | |
148 | xencomm_free((struct xencomm_handle *)__pa(desc)); | |
149 | return rc; | |
150 | } | |
151 | ||
152 | *ret = desc; | |
153 | return 0; | |
154 | } | |
155 | ||
b15993fc IY |
156 | static struct xencomm_handle *xencomm_create_inline(void *ptr) |
157 | { | |
158 | unsigned long paddr; | |
159 | ||
75909fd6 | 160 | BUG_ON(!xencomm_is_phys_contiguous((unsigned long)ptr)); |
b15993fc IY |
161 | |
162 | paddr = (unsigned long)xencomm_pa(ptr); | |
163 | BUG_ON(paddr & XENCOMM_INLINE_FLAG); | |
164 | return (struct xencomm_handle *)(paddr | XENCOMM_INLINE_FLAG); | |
165 | } | |
166 | ||
167 | /* "mini" routine, for stack-based communications: */ | |
168 | static int xencomm_create_mini(void *buffer, | |
169 | unsigned long bytes, struct xencomm_mini *xc_desc, | |
170 | struct xencomm_desc **ret) | |
171 | { | |
172 | int rc = 0; | |
173 | struct xencomm_desc *desc; | |
174 | BUG_ON(((unsigned long)xc_desc) % sizeof(*xc_desc) != 0); | |
175 | ||
176 | desc = (void *)xc_desc; | |
177 | ||
178 | desc->nr_addrs = XENCOMM_MINI_ADDRS; | |
179 | ||
180 | rc = xencomm_init(desc, buffer, bytes); | |
181 | if (!rc) | |
182 | *ret = desc; | |
183 | ||
184 | return rc; | |
185 | } | |
186 | ||
187 | struct xencomm_handle *xencomm_map(void *ptr, unsigned long bytes) | |
188 | { | |
189 | int rc; | |
190 | struct xencomm_desc *desc; | |
191 | ||
75909fd6 | 192 | if (xencomm_is_phys_contiguous((unsigned long)ptr)) |
b15993fc IY |
193 | return xencomm_create_inline(ptr); |
194 | ||
195 | rc = xencomm_create(ptr, bytes, &desc, GFP_KERNEL); | |
196 | ||
197 | if (rc || desc == NULL) | |
198 | return NULL; | |
199 | ||
200 | return xencomm_pa(desc); | |
201 | } | |
202 | ||
203 | struct xencomm_handle *__xencomm_map_no_alloc(void *ptr, unsigned long bytes, | |
204 | struct xencomm_mini *xc_desc) | |
205 | { | |
206 | int rc; | |
207 | struct xencomm_desc *desc = NULL; | |
208 | ||
75909fd6 | 209 | if (xencomm_is_phys_contiguous((unsigned long)ptr)) |
b15993fc IY |
210 | return xencomm_create_inline(ptr); |
211 | ||
212 | rc = xencomm_create_mini(ptr, bytes, xc_desc, | |
213 | &desc); | |
214 | ||
215 | if (rc) | |
216 | return NULL; | |
217 | ||
218 | return xencomm_pa(desc); | |
219 | } |