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.
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.
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
16 * Copyright (C) IBM Corp. 2006
18 * Authors: Hollis Blanchard <hollisb@us.ibm.com>
22 #include <linux/slab.h>
24 #include <xen/xencomm.h>
25 #include <xen/interface/xen.h>
26 #include <asm/xen/xencomm.h> /* for xencomm_is_phys_contiguous() */
28 static int xencomm_init(struct xencomm_desc
*desc
,
29 void *buffer
, unsigned long bytes
)
31 unsigned long recorded
= 0;
34 while ((recorded
< bytes
) && (i
< desc
->nr_addrs
)) {
35 unsigned long vaddr
= (unsigned long)buffer
+ recorded
;
40 offset
= vaddr
% PAGE_SIZE
; /* handle partial pages */
41 chunksz
= min(PAGE_SIZE
- offset
, bytes
- recorded
);
43 paddr
= xencomm_vtop(vaddr
);
45 printk(KERN_DEBUG
"%s: couldn't translate vaddr %lx\n",
50 desc
->address
[i
++] = paddr
;
54 if (recorded
< bytes
) {
56 "%s: could only translate %ld of %ld bytes\n",
57 __func__
, recorded
, bytes
);
61 /* mark remaining addresses invalid (just for safety) */
62 while (i
< desc
->nr_addrs
)
63 desc
->address
[i
++] = XENCOMM_INVALID
;
65 desc
->magic
= XENCOMM_MAGIC
;
70 static struct xencomm_desc
*xencomm_alloc(gfp_t gfp_mask
,
71 void *buffer
, unsigned long bytes
)
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
;
82 * slab allocator returns at least sizeof(void*) aligned pointer.
83 * When sizeof(*desc) > sizeof(void*), struct xencomm_desc might
84 * cross page boundary.
86 if (sizeof(*desc
) > sizeof(void *)) {
87 unsigned long order
= get_order(size
);
88 desc
= (struct xencomm_desc
*)__get_free_pages(gfp_mask
,
94 ((PAGE_SIZE
<< order
) - sizeof(struct xencomm_desc
)) /
95 sizeof(*desc
->address
);
97 desc
= kmalloc(size
, gfp_mask
);
101 desc
->nr_addrs
= nr_addrs
;
106 void xencomm_free(struct xencomm_handle
*desc
)
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
);
120 static int xencomm_create(void *buffer
, unsigned long bytes
,
121 struct xencomm_desc
**ret
, gfp_t gfp_mask
)
123 struct xencomm_desc
*desc
;
126 pr_debug("%s: %p[%ld]\n", __func__
, buffer
, bytes
);
129 /* don't create a descriptor; Xen recognizes NULL. */
130 BUG_ON(buffer
!= NULL
);
135 BUG_ON(buffer
== NULL
); /* 'bytes' is non-zero */
137 desc
= xencomm_alloc(gfp_mask
, buffer
, bytes
);
139 printk(KERN_DEBUG
"%s failure\n", "xencomm_alloc");
143 rc
= xencomm_init(desc
, buffer
, bytes
);
145 printk(KERN_DEBUG
"%s failure: %d\n", "xencomm_init", rc
);
146 xencomm_free((struct xencomm_handle
*)__pa(desc
));
154 static struct xencomm_handle
*xencomm_create_inline(void *ptr
)
158 BUG_ON(!xencomm_is_phys_contiguous((unsigned long)ptr
));
160 paddr
= (unsigned long)xencomm_pa(ptr
);
161 BUG_ON(paddr
& XENCOMM_INLINE_FLAG
);
162 return (struct xencomm_handle
*)(paddr
| XENCOMM_INLINE_FLAG
);
165 /* "mini" routine, for stack-based communications: */
166 static int xencomm_create_mini(void *buffer
,
167 unsigned long bytes
, struct xencomm_mini
*xc_desc
,
168 struct xencomm_desc
**ret
)
171 struct xencomm_desc
*desc
;
172 BUG_ON(((unsigned long)xc_desc
) % sizeof(*xc_desc
) != 0);
174 desc
= (void *)xc_desc
;
176 desc
->nr_addrs
= XENCOMM_MINI_ADDRS
;
178 rc
= xencomm_init(desc
, buffer
, bytes
);
185 struct xencomm_handle
*xencomm_map(void *ptr
, unsigned long bytes
)
188 struct xencomm_desc
*desc
;
190 if (xencomm_is_phys_contiguous((unsigned long)ptr
))
191 return xencomm_create_inline(ptr
);
193 rc
= xencomm_create(ptr
, bytes
, &desc
, GFP_KERNEL
);
195 if (rc
|| desc
== NULL
)
198 return xencomm_pa(desc
);
201 struct xencomm_handle
*__xencomm_map_no_alloc(void *ptr
, unsigned long bytes
,
202 struct xencomm_mini
*xc_desc
)
205 struct xencomm_desc
*desc
= NULL
;
207 if (xencomm_is_phys_contiguous((unsigned long)ptr
))
208 return xencomm_create_inline(ptr
);
210 rc
= xencomm_create_mini(ptr
, bytes
, xc_desc
,
216 return xencomm_pa(desc
);
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