1 /******************************************************************************
2 * arch/xen/drivers/blkif/backend/interface.c
4 * Block-device interface management.
6 * Copyright (c) 2004, Keir Fraser
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:
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:
21 * The above copyright notice and this permission notice shall be included in
22 * all copies or substantial portions of the Software.
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
34 #include <xen/evtchn.h>
35 #include <linux/kthread.h>
36 #include <linux/vmalloc.h>
38 static struct kmem_cache *blkif_cachep;
40 blkif_t *blkif_alloc(domid_t domid)
44 blkif = kmem_cache_zalloc(blkif_cachep, GFP_KERNEL);
46 return ERR_PTR(-ENOMEM);
49 spin_lock_init(&blkif->blk_ring_lock);
50 atomic_set(&blkif->refcnt, 1);
51 init_waitqueue_head(&blkif->wq);
52 init_completion(&blkif->drain_complete);
53 atomic_set(&blkif->drain, 0);
54 blkif->st_print = jiffies;
55 init_waitqueue_head(&blkif->waiting_to_free);
60 int blkif_map(blkif_t *blkif, grant_ref_t ring_ref, evtchn_port_t evtchn)
62 struct vm_struct *area;
65 /* Already connected through? */
69 area = xenbus_map_ring_valloc(blkif->be->dev, ring_ref);
72 blkif->blk_ring_area = area;
74 switch (blkif->blk_protocol) {
75 #define BLKBK_RING_INIT(p) ({ \
76 struct blkif_##p##_sring *sring = area->addr; \
77 BACK_RING_INIT(&blkif->blk_rings.p, sring, PAGE_SIZE); \
79 case BLKIF_PROTOCOL_NATIVE:
80 BLKBK_RING_INIT(native);
82 case BLKIF_PROTOCOL_X86_32:
83 BLKBK_RING_INIT(x86_32);
85 case BLKIF_PROTOCOL_X86_64:
86 BLKBK_RING_INIT(x86_64);
90 #undef BLKBK_RING_INIT
93 err = bind_interdomain_evtchn_to_irqhandler(
94 blkif->domid, evtchn, blkif_be_int, 0, "blkif-backend", blkif);
97 xenbus_unmap_ring_vfree(blkif->be->dev, area);
98 blkif->blk_rings.common.sring = NULL;
106 void blkif_disconnect(blkif_t *blkif)
108 if (blkif->xenblkd) {
109 kthread_stop(blkif->xenblkd);
110 blkif->xenblkd = NULL;
113 atomic_dec(&blkif->refcnt);
114 wait_event(blkif->waiting_to_free, atomic_read(&blkif->refcnt) == 0);
115 atomic_inc(&blkif->refcnt);
118 unbind_from_irqhandler(blkif->irq, blkif);
122 if (blkif->blk_rings.common.sring) {
123 xenbus_unmap_ring_vfree(blkif->be->dev, blkif->blk_ring_area);
124 blkif->blk_rings.common.sring = NULL;
128 void blkif_free(blkif_t *blkif)
130 if (!atomic_dec_and_test(&blkif->refcnt))
132 kmem_cache_free(blkif_cachep, blkif);
135 void __init blkif_interface_init(void)
137 blkif_cachep = kmem_cache_create("blkif_cache", sizeof(blkif_t),