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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
21#include <linux/mm.h>
22#include <linux/slab.h>
23#include <asm/page.h>
24#include <xen/xencomm.h>
25#include <xen/interface/xen.h>
26#include <asm/xen/xencomm.h> /* for xencomm_is_phys_contiguous() */
27
28static int xencomm_init(struct xencomm_desc *desc,
29 void *buffer, unsigned long bytes)
30{
31 unsigned long recorded = 0;
32 int i = 0;
33
34 while ((recorded < bytes) && (i < desc->nr_addrs)) {
35 unsigned long vaddr = (unsigned long)buffer + recorded;
36 unsigned long paddr;
37 int offset;
38 int chunksz;
39
40 offset = vaddr % PAGE_SIZE; /* handle partial pages */
41 chunksz = min(PAGE_SIZE - offset, bytes - recorded);
42
43 paddr = xencomm_vtop(vaddr);
44 if (paddr == ~0UL) {
45 printk(KERN_DEBUG "%s: couldn't translate vaddr %lx\n",
46 __func__, vaddr);
47 return -EINVAL;
48 }
49
50 desc->address[i++] = paddr;
51 recorded += chunksz;
52 }
53
54 if (recorded < bytes) {
55 printk(KERN_DEBUG
56 "%s: could only translate %ld of %ld bytes\n",
57 __func__, recorded, bytes);
58 return -ENOSPC;
59 }
60
61 /* mark remaining addresses invalid (just for safety) */
62 while (i < desc->nr_addrs)
63 desc->address[i++] = XENCOMM_INVALID;
64
65 desc->magic = XENCOMM_MAGIC;
66
67 return 0;
68}
69
70static struct xencomm_desc *xencomm_alloc(gfp_t gfp_mask,
71 void *buffer, unsigned long bytes)
72{
73 struct xencomm_desc *desc;
74 unsigned long buffer_ulong = (unsigned long)buffer;
75 unsigned long start = buffer_ulong & PAGE_MASK;
76 unsigned long end = (buffer_ulong + bytes) | ~PAGE_MASK;
77 unsigned long nr_addrs = (end - start + 1) >> PAGE_SHIFT;
78 unsigned long size = sizeof(*desc) +
79 sizeof(desc->address[0]) * nr_addrs;
80
81 /*
82 * slab allocator returns at least sizeof(void*) aligned pointer.
83 * When sizeof(*desc) > sizeof(void*), struct xencomm_desc might
84 * cross page boundary.
85 */
86 if (sizeof(*desc) > sizeof(void *)) {
87 unsigned long order = get_order(size);
88 desc = (struct xencomm_desc *)__get_free_pages(gfp_mask,
89 order);
90 if (desc == NULL)
91 return NULL;
92
93 desc->nr_addrs =
94 ((PAGE_SIZE << order) - sizeof(struct xencomm_desc)) /
95 sizeof(*desc->address);
96 } else {
97 desc = kmalloc(size, gfp_mask);
98 if (desc == NULL)
99 return NULL;
100
101 desc->nr_addrs = nr_addrs;
102 }
103 return desc;
104}
105
106void xencomm_free(struct xencomm_handle *desc)
107{
108 if (desc && !((ulong)desc & XENCOMM_INLINE_FLAG)) {
109 struct xencomm_desc *desc__ = (struct xencomm_desc *)desc;
110 if (sizeof(*desc__) > sizeof(void *)) {
111 unsigned long size = sizeof(*desc__) +
112 sizeof(desc__->address[0]) * desc__->nr_addrs;
113 unsigned long order = get_order(size);
114 free_pages((unsigned long)__va(desc), order);
115 } else
116 kfree(__va(desc));
117 }
118}
119
120static int xencomm_create(void *buffer, unsigned long bytes,
121 struct xencomm_desc **ret, gfp_t gfp_mask)
122{
123 struct xencomm_desc *desc;
124 int rc;
125
126 pr_debug("%s: %p[%ld]\n", __func__, buffer, bytes);
127
128 if (bytes == 0) {
129 /* don't create a descriptor; Xen recognizes NULL. */
130 BUG_ON(buffer != NULL);
131 *ret = NULL;
132 return 0;
133 }
134
135 BUG_ON(buffer == NULL); /* 'bytes' is non-zero */
136
137 desc = xencomm_alloc(gfp_mask, buffer, bytes);
138 if (!desc) {
139 printk(KERN_DEBUG "%s failure\n", "xencomm_alloc");
140 return -ENOMEM;
141 }
142
143 rc = xencomm_init(desc, buffer, bytes);
144 if (rc) {
145 printk(KERN_DEBUG "%s failure: %d\n", "xencomm_init", rc);
146 xencomm_free((struct xencomm_handle *)__pa(desc));
147 return rc;
148 }
149
150 *ret = desc;
151 return 0;
152}
153
154static struct xencomm_handle *xencomm_create_inline(void *ptr)
155{
156 unsigned long paddr;
157
158 BUG_ON(!xencomm_is_phys_contiguous((unsigned long)ptr));
159
160 paddr = (unsigned long)xencomm_pa(ptr);
161 BUG_ON(paddr & XENCOMM_INLINE_FLAG);
162 return (struct xencomm_handle *)(paddr | XENCOMM_INLINE_FLAG);
163}
164
165/* "mini" routine, for stack-based communications: */
166static int xencomm_create_mini(void *buffer,
167 unsigned long bytes, struct xencomm_mini *xc_desc,
168 struct xencomm_desc **ret)
169{
170 int rc = 0;
171 struct xencomm_desc *desc;
172 BUG_ON(((unsigned long)xc_desc) % sizeof(*xc_desc) != 0);
173
174 desc = (void *)xc_desc;
175
176 desc->nr_addrs = XENCOMM_MINI_ADDRS;
177
178 rc = xencomm_init(desc, buffer, bytes);
179 if (!rc)
180 *ret = desc;
181
182 return rc;
183}
184
185struct xencomm_handle *xencomm_map(void *ptr, unsigned long bytes)
186{
187 int rc;
188 struct xencomm_desc *desc;
189
190 if (xencomm_is_phys_contiguous((unsigned long)ptr))
191 return xencomm_create_inline(ptr);
192
193 rc = xencomm_create(ptr, bytes, &desc, GFP_KERNEL);
194
195 if (rc || desc == NULL)
196 return NULL;
197
198 return xencomm_pa(desc);
199}
200
201struct xencomm_handle *__xencomm_map_no_alloc(void *ptr, unsigned long bytes,
202 struct xencomm_mini *xc_desc)
203{
204 int rc;
205 struct xencomm_desc *desc = NULL;
206
207 if (xencomm_is_phys_contiguous((unsigned long)ptr))
208 return xencomm_create_inline(ptr);
209
210 rc = xencomm_create_mini(ptr, bytes, xc_desc,
211 &desc);
212
213 if (rc)
214 return NULL;
215
216 return xencomm_pa(desc);
217}
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
21#include <linux/mm.h>
22#include <linux/slab.h>
23#include <asm/page.h>
24#include <xen/xencomm.h>
25#include <xen/interface/xen.h>
26#include <asm/xen/xencomm.h> /* for xencomm_is_phys_contiguous() */
27
28static int xencomm_init(struct xencomm_desc *desc,
29 void *buffer, unsigned long bytes)
30{
31 unsigned long recorded = 0;
32 int i = 0;
33
34 while ((recorded < bytes) && (i < desc->nr_addrs)) {
35 unsigned long vaddr = (unsigned long)buffer + recorded;
36 unsigned long paddr;
37 int offset;
38 int chunksz;
39
40 offset = vaddr % PAGE_SIZE; /* handle partial pages */
41 chunksz = min(PAGE_SIZE - offset, bytes - recorded);
42
43 paddr = xencomm_vtop(vaddr);
44 if (paddr == ~0UL) {
45 printk(KERN_DEBUG "%s: couldn't translate vaddr %lx\n",
46 __func__, vaddr);
47 return -EINVAL;
48 }
49
50 desc->address[i++] = paddr;
51 recorded += chunksz;
52 }
53
54 if (recorded < bytes) {
55 printk(KERN_DEBUG
56 "%s: could only translate %ld of %ld bytes\n",
57 __func__, recorded, bytes);
58 return -ENOSPC;
59 }
60
61 /* mark remaining addresses invalid (just for safety) */
62 while (i < desc->nr_addrs)
63 desc->address[i++] = XENCOMM_INVALID;
64
65 desc->magic = XENCOMM_MAGIC;
66
67 return 0;
68}
69
70static struct xencomm_desc *xencomm_alloc(gfp_t gfp_mask,
71 void *buffer, unsigned long bytes)
72{
73 struct xencomm_desc *desc;
74 unsigned long buffer_ulong = (unsigned long)buffer;
75 unsigned long start = buffer_ulong & PAGE_MASK;
76 unsigned long end = (buffer_ulong + bytes) | ~PAGE_MASK;
77 unsigned long nr_addrs = (end - start + 1) >> PAGE_SHIFT;
78 unsigned long size = sizeof(*desc) +
79 sizeof(desc->address[0]) * nr_addrs;
80
81 /*
82 * slab allocator returns at least sizeof(void*) aligned pointer.
83 * When sizeof(*desc) > sizeof(void*), struct xencomm_desc might
84 * cross page boundary.
85 */
86 if (sizeof(*desc) > sizeof(void *)) {
87 unsigned long order = get_order(size);
88 desc = (struct xencomm_desc *)__get_free_pages(gfp_mask,
89 order);
90 if (desc == NULL)
91 return NULL;
92
93 desc->nr_addrs =
94 ((PAGE_SIZE << order) - sizeof(struct xencomm_desc)) /
95 sizeof(*desc->address);
96 } else {
97 desc = kmalloc(size, gfp_mask);
98 if (desc == NULL)
99 return NULL;
100
101 desc->nr_addrs = nr_addrs;
102 }
103 return desc;
104}
105
106void xencomm_free(struct xencomm_handle *desc)
107{
108 if (desc && !((ulong)desc & XENCOMM_INLINE_FLAG)) {
109 struct xencomm_desc *desc__ = (struct xencomm_desc *)desc;
110 if (sizeof(*desc__) > sizeof(void *)) {
111 unsigned long size = sizeof(*desc__) +
112 sizeof(desc__->address[0]) * desc__->nr_addrs;
113 unsigned long order = get_order(size);
114 free_pages((unsigned long)__va(desc), order);
115 } else
116 kfree(__va(desc));
117 }
118}
119
120static int xencomm_create(void *buffer, unsigned long bytes,
121 struct xencomm_desc **ret, gfp_t gfp_mask)
122{
123 struct xencomm_desc *desc;
124 int rc;
125
126 pr_debug("%s: %p[%ld]\n", __func__, buffer, bytes);
127
128 if (bytes == 0) {
129 /* don't create a descriptor; Xen recognizes NULL. */
130 BUG_ON(buffer != NULL);
131 *ret = NULL;
132 return 0;
133 }
134
135 BUG_ON(buffer == NULL); /* 'bytes' is non-zero */
136
137 desc = xencomm_alloc(gfp_mask, buffer, bytes);
138 if (!desc) {
139 printk(KERN_DEBUG "%s failure\n", "xencomm_alloc");
140 return -ENOMEM;
141 }
142
143 rc = xencomm_init(desc, buffer, bytes);
144 if (rc) {
145 printk(KERN_DEBUG "%s failure: %d\n", "xencomm_init", rc);
146 xencomm_free((struct xencomm_handle *)__pa(desc));
147 return rc;
148 }
149
150 *ret = desc;
151 return 0;
152}
153
154static struct xencomm_handle *xencomm_create_inline(void *ptr)
155{
156 unsigned long paddr;
157
158 BUG_ON(!xencomm_is_phys_contiguous((unsigned long)ptr));
159
160 paddr = (unsigned long)xencomm_pa(ptr);
161 BUG_ON(paddr & XENCOMM_INLINE_FLAG);
162 return (struct xencomm_handle *)(paddr | XENCOMM_INLINE_FLAG);
163}
164
165/* "mini" routine, for stack-based communications: */
166static int xencomm_create_mini(void *buffer,
167 unsigned long bytes, struct xencomm_mini *xc_desc,
168 struct xencomm_desc **ret)
169{
170 int rc = 0;
171 struct xencomm_desc *desc;
172 BUG_ON(((unsigned long)xc_desc) % sizeof(*xc_desc) != 0);
173
174 desc = (void *)xc_desc;
175
176 desc->nr_addrs = XENCOMM_MINI_ADDRS;
177
178 rc = xencomm_init(desc, buffer, bytes);
179 if (!rc)
180 *ret = desc;
181
182 return rc;
183}
184
185struct xencomm_handle *xencomm_map(void *ptr, unsigned long bytes)
186{
187 int rc;
188 struct xencomm_desc *desc;
189
190 if (xencomm_is_phys_contiguous((unsigned long)ptr))
191 return xencomm_create_inline(ptr);
192
193 rc = xencomm_create(ptr, bytes, &desc, GFP_KERNEL);
194
195 if (rc || desc == NULL)
196 return NULL;
197
198 return xencomm_pa(desc);
199}
200
201struct xencomm_handle *__xencomm_map_no_alloc(void *ptr, unsigned long bytes,
202 struct xencomm_mini *xc_desc)
203{
204 int rc;
205 struct xencomm_desc *desc = NULL;
206
207 if (xencomm_is_phys_contiguous((unsigned long)ptr))
208 return xencomm_create_inline(ptr);
209
210 rc = xencomm_create_mini(ptr, bytes, xc_desc,
211 &desc);
212
213 if (rc)
214 return NULL;
215
216 return xencomm_pa(desc);
217}