3 * Copyright (c) 2009, Microsoft Corporation.
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms and conditions of the GNU General Public License,
7 * version 2, as published by the Free Software Foundation.
9 * This program is distributed in the hope it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
14 * You should have received a copy of the GNU General Public License along with
15 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
16 * Place - Suite 330, Boston, MA 02111-1307 USA.
19 * Haiyang Zhang <haiyangz@microsoft.com>
20 * Hank Janssen <hjanssen@microsoft.com>
23 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
25 #include <linux/kernel.h>
26 #include <linux/sched.h>
27 #include <linux/wait.h>
28 #include <linux/delay.h>
30 #include <linux/slab.h>
31 #include <linux/vmalloc.h>
34 #include "hyperv_vmbus.h"
37 struct vmbus_connection vmbus_connection = {
38 .conn_state = DISCONNECTED,
39 .next_gpadl_handle = ATOMIC_INIT(0xE1E10),
43 * vmbus_connect - Sends a connect request on the partition service connection
45 int vmbus_connect(void)
49 struct vmbus_channel_msginfo *msginfo = NULL;
50 struct vmbus_channel_initiate_contact *msg;
53 /* Make sure we are not connecting or connected */
54 if (vmbus_connection.conn_state != DISCONNECTED)
57 /* Initialize the vmbus connection */
58 vmbus_connection.conn_state = CONNECTING;
59 vmbus_connection.work_queue = create_workqueue("hv_vmbus_con");
60 if (!vmbus_connection.work_queue) {
65 INIT_LIST_HEAD(&vmbus_connection.chn_msg_list);
66 spin_lock_init(&vmbus_connection.channelmsg_lock);
68 INIT_LIST_HEAD(&vmbus_connection.chn_list);
69 spin_lock_init(&vmbus_connection.channel_lock);
72 * Setup the vmbus event connection for channel interrupt
75 vmbus_connection.int_page =
76 (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, 0);
77 if (vmbus_connection.int_page == NULL) {
82 vmbus_connection.recv_int_page = vmbus_connection.int_page;
83 vmbus_connection.send_int_page =
84 (void *)((unsigned long)vmbus_connection.int_page +
88 * Setup the monitor notification facility. The 1st page for
89 * parent->child and the 2nd page for child->parent
91 vmbus_connection.monitor_pages =
92 (void *)__get_free_pages((GFP_KERNEL|__GFP_ZERO), 1);
93 if (vmbus_connection.monitor_pages == NULL) {
98 msginfo = kzalloc(sizeof(*msginfo) +
99 sizeof(struct vmbus_channel_initiate_contact),
101 if (msginfo == NULL) {
106 init_completion(&msginfo->waitevent);
108 msg = (struct vmbus_channel_initiate_contact *)msginfo->msg;
110 msg->header.msgtype = CHANNELMSG_INITIATE_CONTACT;
111 msg->vmbus_version_requested = VMBUS_REVISION_NUMBER;
112 msg->interrupt_page = virt_to_phys(vmbus_connection.int_page);
113 msg->monitor_page1 = virt_to_phys(vmbus_connection.monitor_pages);
114 msg->monitor_page2 = virt_to_phys(
115 (void *)((unsigned long)vmbus_connection.monitor_pages +
119 * Add to list before we send the request since we may
120 * receive the response before returning from this routine
122 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
123 list_add_tail(&msginfo->msglistentry,
124 &vmbus_connection.chn_msg_list);
126 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
128 ret = vmbus_post_msg(msg,
129 sizeof(struct vmbus_channel_initiate_contact));
131 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
132 list_del(&msginfo->msglistentry);
133 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock,
138 /* Wait for the connection response */
139 t = wait_for_completion_timeout(&msginfo->waitevent, 5*HZ);
141 spin_lock_irqsave(&vmbus_connection.channelmsg_lock,
143 list_del(&msginfo->msglistentry);
144 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock,
150 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
151 list_del(&msginfo->msglistentry);
152 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
154 /* Check if successful */
155 if (msginfo->response.version_response.version_supported) {
156 vmbus_connection.conn_state = CONNECTED;
158 pr_err("Unable to connect, "
159 "Version %d not supported by Hyper-V\n",
160 VMBUS_REVISION_NUMBER);
169 vmbus_connection.conn_state = DISCONNECTED;
171 if (vmbus_connection.work_queue)
172 destroy_workqueue(vmbus_connection.work_queue);
174 if (vmbus_connection.int_page) {
175 free_pages((unsigned long)vmbus_connection.int_page, 0);
176 vmbus_connection.int_page = NULL;
179 if (vmbus_connection.monitor_pages) {
180 free_pages((unsigned long)vmbus_connection.monitor_pages, 1);
181 vmbus_connection.monitor_pages = NULL;
191 * relid2channel - Get the channel object given its
192 * child relative id (ie channel id)
194 struct vmbus_channel *relid2channel(u32 relid)
196 struct vmbus_channel *channel;
197 struct vmbus_channel *found_channel = NULL;
200 spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
201 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
202 if (channel->offermsg.child_relid == relid) {
203 found_channel = channel;
207 spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
209 return found_channel;
213 * process_chn_event - Process a channel event notification
215 static void process_chn_event(u32 relid)
217 struct vmbus_channel *channel;
221 * Find the channel based on this relid and invokes the
222 * channel callback to process the event
224 channel = relid2channel(relid);
226 spin_lock_irqsave(&channel->inbound_lock, flags);
227 if (channel && (channel->onchannel_callback != NULL)) {
228 channel->onchannel_callback(channel->channel_callback_context);
230 pr_err("channel not found for relid - %u\n", relid);
232 spin_unlock_irqrestore(&channel->inbound_lock, flags);
236 * vmbus_on_event - Handler for events
238 void vmbus_on_event(unsigned long data)
241 u32 maxdword = MAX_NUM_CHANNELS_SUPPORTED >> 5;
244 u32 *recv_int_page = vmbus_connection.recv_int_page;
249 for (dword = 0; dword < maxdword; dword++) {
250 if (!recv_int_page[dword])
252 for (bit = 0; bit < 32; bit++) {
253 if (sync_test_and_clear_bit(bit, (unsigned long *)&recv_int_page[dword])) {
254 relid = (dword << 5) + bit;
258 * Special case - vmbus
259 * channel protocol msg
263 process_chn_event(relid);
270 * vmbus_post_msg - Send a msg on the vmbus's message connection
272 int vmbus_post_msg(void *buffer, size_t buflen)
274 union hv_connection_id conn_id;
279 conn_id.u.id = VMBUS_MESSAGE_CONNECTION_ID;
282 * hv_post_message() can have transient failures because of
283 * insufficient resources. Retry the operation a couple of
284 * times before giving up.
286 while (retries < 3) {
287 ret = hv_post_message(conn_id, 1, buffer, buflen);
288 if (ret != HV_STATUS_INSUFFICIENT_BUFFERS)
297 * vmbus_set_event - Send an event notification to the parent
299 int vmbus_set_event(u32 child_relid)
301 /* Each u32 represents 32 channels */
302 sync_set_bit(child_relid & 31,
303 (unsigned long *)vmbus_connection.send_int_page +
306 return hv_signal_event();