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-rw-r--r--drivers/xen/Makefile1
-rw-r--r--drivers/xen/xencomm.c232
-rw-r--r--include/xen/interface/xencomm.h41
-rw-r--r--include/xen/xencomm.h77
4 files changed, 351 insertions, 0 deletions
diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
index 823ce788b14b..43f014cfb458 100644
--- a/drivers/xen/Makefile
+++ b/drivers/xen/Makefile
@@ -1,2 +1,3 @@
1obj-y += grant-table.o features.o events.o 1obj-y += grant-table.o features.o events.o
2obj-y += xenbus/ 2obj-y += xenbus/
3obj-$(CONFIG_XEN_XENCOMM) += xencomm.o
diff --git a/drivers/xen/xencomm.c b/drivers/xen/xencomm.c
new file mode 100644
index 000000000000..797cb4e31f07
--- /dev/null
+++ b/drivers/xen/xencomm.c
@@ -0,0 +1,232 @@
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/gfp.h>
22#include <linux/mm.h>
23#include <asm/page.h>
24#include <xen/xencomm.h>
25#include <xen/interface/xen.h>
26#ifdef __ia64__
27#include <asm/xen/xencomm.h> /* for is_kern_addr() */
28#endif
29
30#ifdef HAVE_XEN_PLATFORM_COMPAT_H
31#include <xen/platform-compat.h>
32#endif
33
34static int xencomm_init(struct xencomm_desc *desc,
35 void *buffer, unsigned long bytes)
36{
37 unsigned long recorded = 0;
38 int i = 0;
39
40 while ((recorded < bytes) && (i < desc->nr_addrs)) {
41 unsigned long vaddr = (unsigned long)buffer + recorded;
42 unsigned long paddr;
43 int offset;
44 int chunksz;
45
46 offset = vaddr % PAGE_SIZE; /* handle partial pages */
47 chunksz = min(PAGE_SIZE - offset, bytes - recorded);
48
49 paddr = xencomm_vtop(vaddr);
50 if (paddr == ~0UL) {
51 printk(KERN_DEBUG "%s: couldn't translate vaddr %lx\n",
52 __func__, vaddr);
53 return -EINVAL;
54 }
55
56 desc->address[i++] = paddr;
57 recorded += chunksz;
58 }
59
60 if (recorded < bytes) {
61 printk(KERN_DEBUG
62 "%s: could only translate %ld of %ld bytes\n",
63 __func__, recorded, bytes);
64 return -ENOSPC;
65 }
66
67 /* mark remaining addresses invalid (just for safety) */
68 while (i < desc->nr_addrs)
69 desc->address[i++] = XENCOMM_INVALID;
70
71 desc->magic = XENCOMM_MAGIC;
72
73 return 0;
74}
75
76static struct xencomm_desc *xencomm_alloc(gfp_t gfp_mask,
77 void *buffer, unsigned long bytes)
78{
79 struct xencomm_desc *desc;
80 unsigned long buffer_ulong = (unsigned long)buffer;
81 unsigned long start = buffer_ulong & PAGE_MASK;
82 unsigned long end = (buffer_ulong + bytes) | ~PAGE_MASK;
83 unsigned long nr_addrs = (end - start + 1) >> PAGE_SHIFT;
84 unsigned long size = sizeof(*desc) +
85 sizeof(desc->address[0]) * nr_addrs;
86
87 /*
88 * slab allocator returns at least sizeof(void*) aligned pointer.
89 * When sizeof(*desc) > sizeof(void*), struct xencomm_desc might
90 * cross page boundary.
91 */
92 if (sizeof(*desc) > sizeof(void *)) {
93 unsigned long order = get_order(size);
94 desc = (struct xencomm_desc *)__get_free_pages(gfp_mask,
95 order);
96 if (desc == NULL)
97 return NULL;
98
99 desc->nr_addrs =
100 ((PAGE_SIZE << order) - sizeof(struct xencomm_desc)) /
101 sizeof(*desc->address);
102 } else {
103 desc = kmalloc(size, gfp_mask);
104 if (desc == NULL)
105 return NULL;
106
107 desc->nr_addrs = nr_addrs;
108 }
109 return desc;
110}
111
112void xencomm_free(struct xencomm_handle *desc)
113{
114 if (desc && !((ulong)desc & XENCOMM_INLINE_FLAG)) {
115 struct xencomm_desc *desc__ = (struct xencomm_desc *)desc;
116 if (sizeof(*desc__) > sizeof(void *)) {
117 unsigned long size = sizeof(*desc__) +
118 sizeof(desc__->address[0]) * desc__->nr_addrs;
119 unsigned long order = get_order(size);
120 free_pages((unsigned long)__va(desc), order);
121 } else
122 kfree(__va(desc));
123 }
124}
125
126static int xencomm_create(void *buffer, unsigned long bytes,
127 struct xencomm_desc **ret, gfp_t gfp_mask)
128{
129 struct xencomm_desc *desc;
130 int rc;
131
132 pr_debug("%s: %p[%ld]\n", __func__, buffer, bytes);
133
134 if (bytes == 0) {
135 /* don't create a descriptor; Xen recognizes NULL. */
136 BUG_ON(buffer != NULL);
137 *ret = NULL;
138 return 0;
139 }
140
141 BUG_ON(buffer == NULL); /* 'bytes' is non-zero */
142
143 desc = xencomm_alloc(gfp_mask, buffer, bytes);
144 if (!desc) {
145 printk(KERN_DEBUG "%s failure\n", "xencomm_alloc");
146 return -ENOMEM;
147 }
148
149 rc = xencomm_init(desc, buffer, bytes);
150 if (rc) {
151 printk(KERN_DEBUG "%s failure: %d\n", "xencomm_init", rc);
152 xencomm_free((struct xencomm_handle *)__pa(desc));
153 return rc;
154 }
155
156 *ret = desc;
157 return 0;
158}
159
160/* check if memory address is within VMALLOC region */
161static int is_phys_contiguous(unsigned long addr)
162{
163 if (!is_kernel_addr(addr))
164 return 0;
165
166 return (addr < VMALLOC_START) || (addr >= VMALLOC_END);
167}
168
169static struct xencomm_handle *xencomm_create_inline(void *ptr)
170{
171 unsigned long paddr;
172
173 BUG_ON(!is_phys_contiguous((unsigned long)ptr));
174
175 paddr = (unsigned long)xencomm_pa(ptr);
176 BUG_ON(paddr & XENCOMM_INLINE_FLAG);
177 return (struct xencomm_handle *)(paddr | XENCOMM_INLINE_FLAG);
178}
179
180/* "mini" routine, for stack-based communications: */
181static int xencomm_create_mini(void *buffer,
182 unsigned long bytes, struct xencomm_mini *xc_desc,
183 struct xencomm_desc **ret)
184{
185 int rc = 0;
186 struct xencomm_desc *desc;
187 BUG_ON(((unsigned long)xc_desc) % sizeof(*xc_desc) != 0);
188
189 desc = (void *)xc_desc;
190
191 desc->nr_addrs = XENCOMM_MINI_ADDRS;
192
193 rc = xencomm_init(desc, buffer, bytes);
194 if (!rc)
195 *ret = desc;
196
197 return rc;
198}
199
200struct xencomm_handle *xencomm_map(void *ptr, unsigned long bytes)
201{
202 int rc;
203 struct xencomm_desc *desc;
204
205 if (is_phys_contiguous((unsigned long)ptr))
206 return xencomm_create_inline(ptr);
207
208 rc = xencomm_create(ptr, bytes, &desc, GFP_KERNEL);
209
210 if (rc || desc == NULL)
211 return NULL;
212
213 return xencomm_pa(desc);
214}
215
216struct xencomm_handle *__xencomm_map_no_alloc(void *ptr, unsigned long bytes,
217 struct xencomm_mini *xc_desc)
218{
219 int rc;
220 struct xencomm_desc *desc = NULL;
221
222 if (is_phys_contiguous((unsigned long)ptr))
223 return xencomm_create_inline(ptr);
224
225 rc = xencomm_create_mini(ptr, bytes, xc_desc,
226 &desc);
227
228 if (rc)
229 return NULL;
230
231 return xencomm_pa(desc);
232}
diff --git a/include/xen/interface/xencomm.h b/include/xen/interface/xencomm.h
new file mode 100644
index 000000000000..ac45e0712afa
--- /dev/null
+++ b/include/xen/interface/xencomm.h
@@ -0,0 +1,41 @@
1/*
2 * Permission is hereby granted, free of charge, to any person obtaining a copy
3 * of this software and associated documentation files (the "Software"), to
4 * deal in the Software without restriction, including without limitation the
5 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
6 * sell copies of the Software, and to permit persons to whom the Software is
7 * furnished to do so, subject to the following conditions:
8 *
9 * The above copyright notice and this permission notice shall be included in
10 * all copies or substantial portions of the Software.
11 *
12 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
13 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
14 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
15 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
16 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
17 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
18 * DEALINGS IN THE SOFTWARE.
19 *
20 * Copyright (C) IBM Corp. 2006
21 */
22
23#ifndef _XEN_XENCOMM_H_
24#define _XEN_XENCOMM_H_
25
26/* A xencomm descriptor is a scatter/gather list containing physical
27 * addresses corresponding to a virtually contiguous memory area. The
28 * hypervisor translates these physical addresses to machine addresses to copy
29 * to and from the virtually contiguous area.
30 */
31
32#define XENCOMM_MAGIC 0x58434F4D /* 'XCOM' */
33#define XENCOMM_INVALID (~0UL)
34
35struct xencomm_desc {
36 uint32_t magic;
37 uint32_t nr_addrs; /* the number of entries in address[] */
38 uint64_t address[0];
39};
40
41#endif /* _XEN_XENCOMM_H_ */
diff --git a/include/xen/xencomm.h b/include/xen/xencomm.h
new file mode 100644
index 000000000000..e43b039be112
--- /dev/null
+++ b/include/xen/xencomm.h
@@ -0,0 +1,77 @@
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 * Jerone Young <jyoung5@us.ibm.com>
20 */
21
22#ifndef _LINUX_XENCOMM_H_
23#define _LINUX_XENCOMM_H_
24
25#include <xen/interface/xencomm.h>
26
27#define XENCOMM_MINI_ADDRS 3
28struct xencomm_mini {
29 struct xencomm_desc _desc;
30 uint64_t address[XENCOMM_MINI_ADDRS];
31};
32
33/* To avoid additionnal virt to phys conversion, an opaque structure is
34 presented. */
35struct xencomm_handle;
36
37extern void xencomm_free(struct xencomm_handle *desc);
38extern struct xencomm_handle *xencomm_map(void *ptr, unsigned long bytes);
39extern struct xencomm_handle *__xencomm_map_no_alloc(void *ptr,
40 unsigned long bytes, struct xencomm_mini *xc_area);
41
42#if 0
43#define XENCOMM_MINI_ALIGNED(xc_desc, n) \
44 struct xencomm_mini xc_desc ## _base[(n)] \
45 __attribute__((__aligned__(sizeof(struct xencomm_mini)))); \
46 struct xencomm_mini *xc_desc = &xc_desc ## _base[0];
47#else
48/*
49 * gcc bug workaround:
50 * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16660
51 * gcc doesn't handle properly stack variable with
52 * __attribute__((__align__(sizeof(struct xencomm_mini))))
53 */
54#define XENCOMM_MINI_ALIGNED(xc_desc, n) \
55 unsigned char xc_desc ## _base[((n) + 1 ) * \
56 sizeof(struct xencomm_mini)]; \
57 struct xencomm_mini *xc_desc = (struct xencomm_mini *) \
58 ((unsigned long)xc_desc ## _base + \
59 (sizeof(struct xencomm_mini) - \
60 ((unsigned long)xc_desc ## _base) % \
61 sizeof(struct xencomm_mini)));
62#endif
63#define xencomm_map_no_alloc(ptr, bytes) \
64 ({ XENCOMM_MINI_ALIGNED(xc_desc, 1); \
65 __xencomm_map_no_alloc(ptr, bytes, xc_desc); })
66
67/* provided by architecture code: */
68extern unsigned long xencomm_vtop(unsigned long vaddr);
69
70static inline void *xencomm_pa(void *ptr)
71{
72 return (void *)xencomm_vtop((unsigned long)ptr);
73}
74
75#define xen_guest_handle(hnd) ((hnd).p)
76
77#endif /* _LINUX_XENCOMM_H_ */
generated by cgit v1.2.2 (git 2.25.0) at 2025-12-20 22:42:39 -0500