]>
git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - drivers/xen/xencomm.c
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>
21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
24 #include <linux/slab.h>
26 #include <xen/xencomm.h>
27 #include <xen/interface/xen.h>
28 #include <asm/xen/xencomm.h> /* for xencomm_is_phys_contiguous() */
30 static int xencomm_init(struct xencomm_desc
*desc
,
31 void *buffer
, unsigned long bytes
)
33 unsigned long recorded
= 0;
36 while ((recorded
< bytes
) && (i
< desc
->nr_addrs
)) {
37 unsigned long vaddr
= (unsigned long)buffer
+ recorded
;
42 offset
= vaddr
% PAGE_SIZE
; /* handle partial pages */
43 chunksz
= min(PAGE_SIZE
- offset
, bytes
- recorded
);
45 paddr
= xencomm_vtop(vaddr
);
47 printk(KERN_DEBUG
"%s: couldn't translate vaddr %lx\n",
52 desc
->address
[i
++] = paddr
;
56 if (recorded
< bytes
) {
58 "%s: could only translate %ld of %ld bytes\n",
59 __func__
, recorded
, bytes
);
63 /* mark remaining addresses invalid (just for safety) */
64 while (i
< desc
->nr_addrs
)
65 desc
->address
[i
++] = XENCOMM_INVALID
;
67 desc
->magic
= XENCOMM_MAGIC
;
72 static struct xencomm_desc
*xencomm_alloc(gfp_t gfp_mask
,
73 void *buffer
, unsigned long bytes
)
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
;
84 * slab allocator returns at least sizeof(void*) aligned pointer.
85 * When sizeof(*desc) > sizeof(void*), struct xencomm_desc might
86 * cross page boundary.
88 if (sizeof(*desc
) > sizeof(void *)) {
89 unsigned long order
= get_order(size
);
90 desc
= (struct xencomm_desc
*)__get_free_pages(gfp_mask
,
96 ((PAGE_SIZE
<< order
) - sizeof(struct xencomm_desc
)) /
97 sizeof(*desc
->address
);
99 desc
= kmalloc(size
, gfp_mask
);
103 desc
->nr_addrs
= nr_addrs
;
108 void xencomm_free(struct xencomm_handle
*desc
)
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
);
122 static int xencomm_create(void *buffer
, unsigned long bytes
,
123 struct xencomm_desc
**ret
, gfp_t gfp_mask
)
125 struct xencomm_desc
*desc
;
128 pr_debug("%s: %p[%ld]\n", __func__
, buffer
, bytes
);
131 /* don't create a descriptor; Xen recognizes NULL. */
132 BUG_ON(buffer
!= NULL
);
137 BUG_ON(buffer
== NULL
); /* 'bytes' is non-zero */
139 desc
= xencomm_alloc(gfp_mask
, buffer
, bytes
);
141 printk(KERN_DEBUG
"%s failure\n", "xencomm_alloc");
145 rc
= xencomm_init(desc
, buffer
, bytes
);
147 printk(KERN_DEBUG
"%s failure: %d\n", "xencomm_init", rc
);
148 xencomm_free((struct xencomm_handle
*)__pa(desc
));
156 static struct xencomm_handle
*xencomm_create_inline(void *ptr
)
160 BUG_ON(!xencomm_is_phys_contiguous((unsigned long)ptr
));
162 paddr
= (unsigned long)xencomm_pa(ptr
);
163 BUG_ON(paddr
& XENCOMM_INLINE_FLAG
);
164 return (struct xencomm_handle
*)(paddr
| XENCOMM_INLINE_FLAG
);
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
)
173 struct xencomm_desc
*desc
;
174 BUG_ON(((unsigned long)xc_desc
) % sizeof(*xc_desc
) != 0);
176 desc
= (void *)xc_desc
;
178 desc
->nr_addrs
= XENCOMM_MINI_ADDRS
;
180 rc
= xencomm_init(desc
, buffer
, bytes
);
187 struct xencomm_handle
*xencomm_map(void *ptr
, unsigned long bytes
)
190 struct xencomm_desc
*desc
;
192 if (xencomm_is_phys_contiguous((unsigned long)ptr
))
193 return xencomm_create_inline(ptr
);
195 rc
= xencomm_create(ptr
, bytes
, &desc
, GFP_KERNEL
);
197 if (rc
|| desc
== NULL
)
200 return xencomm_pa(desc
);
203 struct xencomm_handle
*__xencomm_map_no_alloc(void *ptr
, unsigned long bytes
,
204 struct xencomm_mini
*xc_desc
)
207 struct xencomm_desc
*desc
= NULL
;
209 if (xencomm_is_phys_contiguous((unsigned long)ptr
))
210 return xencomm_create_inline(ptr
);
212 rc
= xencomm_create_mini(ptr
, bytes
, xc_desc
,
218 return xencomm_pa(desc
);