ia64/xen-unstable

view linux-2.6-xen-sparse/drivers/xen/blktap/interface.c @ 13991:c4ed5b740a8d

linux: remove {lock,unlock}_vm_area(). Instead use vmalloc_sync_all()
in alloc_vm_area().
Signed-off-by: Keir Fraser <keir@xensource.com>
author kfraser@localhost.localdomain
date Fri Feb 16 11:24:10 2007 +0000 (2007-02-16)
parents c9ac0bace498
children b915eb96097a
line source
1 /******************************************************************************
2 * drivers/xen/blktap/interface.c
3 *
4 * Block-device interface management.
5 *
6 * Copyright (c) 2004, Keir Fraser
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License version 2
10 * as published by the Free Software Foundation; or, when distributed
11 * separately from the Linux kernel or incorporated into other
12 * software packages, subject to the following license:
13 *
14 * Permission is hereby granted, free of charge, to any person obtaining a copy
15 * of this source file (the "Software"), to deal in the Software without
16 * restriction, including without limitation the rights to use, copy, modify,
17 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
18 * and to permit persons to whom the Software is furnished to do so, subject to
19 * the following conditions:
20 *
21 * The above copyright notice and this permission notice shall be included in
22 * all copies or substantial portions of the Software.
23 *
24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
25 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
26 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
27 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
28 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
29 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
30 * IN THE SOFTWARE.
32 */
34 #include "common.h"
35 #include <xen/evtchn.h>
37 static kmem_cache_t *blkif_cachep;
39 blkif_t *tap_alloc_blkif(domid_t domid)
40 {
41 blkif_t *blkif;
43 blkif = kmem_cache_alloc(blkif_cachep, GFP_KERNEL);
44 if (!blkif)
45 return ERR_PTR(-ENOMEM);
47 memset(blkif, 0, sizeof(*blkif));
48 blkif->domid = domid;
49 spin_lock_init(&blkif->blk_ring_lock);
50 atomic_set(&blkif->refcnt, 1);
51 init_waitqueue_head(&blkif->wq);
52 blkif->st_print = jiffies;
53 init_waitqueue_head(&blkif->waiting_to_free);
55 return blkif;
56 }
58 static int map_frontend_page(blkif_t *blkif, unsigned long shared_page)
59 {
60 struct gnttab_map_grant_ref op;
62 gnttab_set_map_op(&op, (unsigned long)blkif->blk_ring_area->addr,
63 GNTMAP_host_map, shared_page, blkif->domid);
65 if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1))
66 BUG();
68 if (op.status) {
69 DPRINTK(" Grant table operation failure !\n");
70 return op.status;
71 }
73 blkif->shmem_ref = shared_page;
74 blkif->shmem_handle = op.handle;
76 return 0;
77 }
79 static void unmap_frontend_page(blkif_t *blkif)
80 {
81 struct gnttab_unmap_grant_ref op;
83 gnttab_set_unmap_op(&op, (unsigned long)blkif->blk_ring_area->addr,
84 GNTMAP_host_map, blkif->shmem_handle);
86 if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, &op, 1))
87 BUG();
88 }
90 int tap_blkif_map(blkif_t *blkif, unsigned long shared_page,
91 unsigned int evtchn)
92 {
93 int err;
95 /* Already connected through? */
96 if (blkif->irq)
97 return 0;
99 if ( (blkif->blk_ring_area = alloc_vm_area(PAGE_SIZE)) == NULL )
100 return -ENOMEM;
102 err = map_frontend_page(blkif, shared_page);
103 if (err) {
104 free_vm_area(blkif->blk_ring_area);
105 return err;
106 }
108 switch (blkif->blk_protocol) {
109 case BLKIF_PROTOCOL_NATIVE:
110 {
111 blkif_sring_t *sring;
112 sring = (blkif_sring_t *)blkif->blk_ring_area->addr;
113 BACK_RING_INIT(&blkif->blk_rings.native, sring, PAGE_SIZE);
114 break;
115 }
116 case BLKIF_PROTOCOL_X86_32:
117 {
118 blkif_x86_32_sring_t *sring_x86_32;
119 sring_x86_32 = (blkif_x86_32_sring_t *)blkif->blk_ring_area->addr;
120 BACK_RING_INIT(&blkif->blk_rings.x86_32, sring_x86_32, PAGE_SIZE);
121 break;
122 }
123 case BLKIF_PROTOCOL_X86_64:
124 {
125 blkif_x86_64_sring_t *sring_x86_64;
126 sring_x86_64 = (blkif_x86_64_sring_t *)blkif->blk_ring_area->addr;
127 BACK_RING_INIT(&blkif->blk_rings.x86_64, sring_x86_64, PAGE_SIZE);
128 break;
129 }
130 default:
131 BUG();
132 }
134 err = bind_interdomain_evtchn_to_irqhandler(
135 blkif->domid, evtchn, tap_blkif_be_int,
136 0, "blkif-backend", blkif);
137 if (err < 0) {
138 unmap_frontend_page(blkif);
139 free_vm_area(blkif->blk_ring_area);
140 return err;
141 }
142 blkif->irq = err;
144 return 0;
145 }
147 void tap_blkif_unmap(blkif_t *blkif)
148 {
149 if (blkif->irq) {
150 unbind_from_irqhandler(blkif->irq, blkif);
151 blkif->irq = 0;
152 }
153 if (blkif->blk_rings.common.sring) {
154 unmap_frontend_page(blkif);
155 free_vm_area(blkif->blk_ring_area);
156 blkif->blk_rings.common.sring = NULL;
157 }
158 }
160 void tap_blkif_free(blkif_t *blkif)
161 {
162 atomic_dec(&blkif->refcnt);
163 wait_event(blkif->waiting_to_free, atomic_read(&blkif->refcnt) == 0);
165 tap_blkif_unmap(blkif);
166 kmem_cache_free(blkif_cachep, blkif);
167 }
169 void __init tap_blkif_interface_init(void)
170 {
171 blkif_cachep = kmem_cache_create("blktapif_cache", sizeof(blkif_t),
172 0, 0, NULL, NULL);
173 }