ia64/xen-unstable

view linux-2.6-xen-sparse/drivers/xen/blkback/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 * arch/xen/drivers/blkif/backend/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.
31 */
33 #include "common.h"
34 #include <xen/evtchn.h>
35 #include <linux/kthread.h>
37 static kmem_cache_t *blkif_cachep;
39 blkif_t *blkif_alloc(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 blkif_map(blkif_t *blkif, unsigned long shared_page, unsigned int evtchn)
91 {
92 int err;
94 /* Already connected through? */
95 if (blkif->irq)
96 return 0;
98 if ( (blkif->blk_ring_area = alloc_vm_area(PAGE_SIZE)) == NULL )
99 return -ENOMEM;
101 err = map_frontend_page(blkif, shared_page);
102 if (err) {
103 free_vm_area(blkif->blk_ring_area);
104 return err;
105 }
107 switch (blkif->blk_protocol) {
108 case BLKIF_PROTOCOL_NATIVE:
109 {
110 blkif_sring_t *sring;
111 sring = (blkif_sring_t *)blkif->blk_ring_area->addr;
112 BACK_RING_INIT(&blkif->blk_rings.native, sring, PAGE_SIZE);
113 break;
114 }
115 case BLKIF_PROTOCOL_X86_32:
116 {
117 blkif_x86_32_sring_t *sring_x86_32;
118 sring_x86_32 = (blkif_x86_32_sring_t *)blkif->blk_ring_area->addr;
119 BACK_RING_INIT(&blkif->blk_rings.x86_32, sring_x86_32, PAGE_SIZE);
120 break;
121 }
122 case BLKIF_PROTOCOL_X86_64:
123 {
124 blkif_x86_64_sring_t *sring_x86_64;
125 sring_x86_64 = (blkif_x86_64_sring_t *)blkif->blk_ring_area->addr;
126 BACK_RING_INIT(&blkif->blk_rings.x86_64, sring_x86_64, PAGE_SIZE);
127 break;
128 }
129 default:
130 BUG();
131 }
133 err = bind_interdomain_evtchn_to_irqhandler(
134 blkif->domid, evtchn, blkif_be_int, 0, "blkif-backend", blkif);
135 if (err < 0)
136 {
137 unmap_frontend_page(blkif);
138 free_vm_area(blkif->blk_ring_area);
139 return err;
140 }
141 blkif->irq = err;
143 return 0;
144 }
146 void blkif_disconnect(blkif_t *blkif)
147 {
148 if (blkif->xenblkd) {
149 kthread_stop(blkif->xenblkd);
150 blkif->xenblkd = NULL;
151 }
153 atomic_dec(&blkif->refcnt);
154 wait_event(blkif->waiting_to_free, atomic_read(&blkif->refcnt) == 0);
155 atomic_inc(&blkif->refcnt);
157 if (blkif->irq) {
158 unbind_from_irqhandler(blkif->irq, blkif);
159 blkif->irq = 0;
160 }
162 if (blkif->blk_rings.common.sring) {
163 unmap_frontend_page(blkif);
164 free_vm_area(blkif->blk_ring_area);
165 blkif->blk_rings.common.sring = NULL;
166 }
167 }
169 void blkif_free(blkif_t *blkif)
170 {
171 if (!atomic_dec_and_test(&blkif->refcnt))
172 BUG();
173 kmem_cache_free(blkif_cachep, blkif);
174 }
176 void __init blkif_interface_init(void)
177 {
178 blkif_cachep = kmem_cache_create("blkif_cache", sizeof(blkif_t),
179 0, 0, NULL, NULL);
180 }