drivers/staging/hv/connection.c

   1 /*
   2  *
   3  * Copyright (c) 2009, Microsoft Corporation.
   4  *
   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.
   8  *
   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
  12  * more details.
  13  *
  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.
  17  *
  18  * Authors:
  19  *   Haiyang Zhang <haiyangz@microsoft.com>
  20  *   Hank Janssen  <hjanssen@microsoft.com>
  21  *
  22  */
  23 #include <linux/kernel.h>
  24 #include <linux/mm.h>
  25 #include <linux/slab.h>
  26 #include <linux/vmalloc.h>
  27 #include "osd.h"
  28 #include "logging.h"
  29 #include "vmbus_private.h"
  30
  31
  32 struct VMBUS_CONNECTION gVmbusConnection = {
  33         .ConnectState           = Disconnected,
  34         .NextGpadlHandle        = ATOMIC_INIT(0xE1E10),
  35 };
  36
  37 /*
  38  * VmbusConnect - Sends a connect request on the partition service connection
  39  */
  40 int VmbusConnect(void)
  41 {
  42         int ret = 0;
  43         struct vmbus_channel_msginfo *msgInfo = NULL;
  44         struct vmbus_channel_initiate_contact *msg;
  45         unsigned long flags;
  46
  47         /* Make sure we are not connecting or connected */
  48         if (gVmbusConnection.ConnectState != Disconnected)
  49                 return -1;
  50
  51         /* Initialize the vmbus connection */
  52         gVmbusConnection.ConnectState = Connecting;
  53         gVmbusConnection.WorkQueue = create_workqueue("hv_vmbus_con");
  54         if (!gVmbusConnection.WorkQueue) {
  55                 ret = -1;
  56                 goto Cleanup;
  57         }
  58
  59         INIT_LIST_HEAD(&gVmbusConnection.ChannelMsgList);
  60         spin_lock_init(&gVmbusConnection.channelmsg_lock);
  61
  62         INIT_LIST_HEAD(&gVmbusConnection.ChannelList);
  63         spin_lock_init(&gVmbusConnection.channel_lock);
  64
  65         /*
  66          * Setup the vmbus event connection for channel interrupt
  67          * abstraction stuff
  68          */
  69         gVmbusConnection.InterruptPage = osd_page_alloc(1);
  70         if (gVmbusConnection.InterruptPage == NULL) {
  71                 ret = -1;
  72                 goto Cleanup;
  73         }
  74
  75         gVmbusConnection.RecvInterruptPage = gVmbusConnection.InterruptPage;
  76         gVmbusConnection.SendInterruptPage =
  77                 (void *)((unsigned long)gVmbusConnection.InterruptPage +
  78                         (PAGE_SIZE >> 1));
  79
  80         /*
  81          * Setup the monitor notification facility. The 1st page for
  82          * parent->child and the 2nd page for child->parent
  83          */
  84         gVmbusConnection.MonitorPages = osd_page_alloc(2);
  85         if (gVmbusConnection.MonitorPages == NULL) {
  86                 ret = -1;
  87                 goto Cleanup;
  88         }
  89
  90         msgInfo = kzalloc(sizeof(*msgInfo) +
  91                           sizeof(struct vmbus_channel_initiate_contact),
  92                           GFP_KERNEL);
  93         if (msgInfo == NULL) {
  94                 ret = -ENOMEM;
  95                 goto Cleanup;
  96         }
  97
  98         msgInfo->waitevent = osd_waitevent_create();
  99         if (!msgInfo->waitevent) {
 100                 ret = -ENOMEM;
 101                 goto Cleanup;
 102         }
 103
 104         msg = (struct vmbus_channel_initiate_contact *)msgInfo->msg;
 105
 106         msg->header.msgtype = CHANNELMSG_INITIATE_CONTACT;
 107         msg->vmbus_version_requested = VMBUS_REVISION_NUMBER;
 108         msg->interrupt_page = virt_to_phys(gVmbusConnection.InterruptPage);
 109         msg->monitor_page1 = virt_to_phys(gVmbusConnection.MonitorPages);
 110         msg->monitor_page2 = virt_to_phys(
 111                         (void *)((unsigned long)gVmbusConnection.MonitorPages +
 112                                  PAGE_SIZE));
 113
 114         /*
 115          * Add to list before we send the request since we may
 116          * receive the response before returning from this routine
 117          */
 118         spin_lock_irqsave(&gVmbusConnection.channelmsg_lock, flags);
 119         list_add_tail(&msgInfo->msglistentry,
 120                       &gVmbusConnection.ChannelMsgList);
 121
 122         spin_unlock_irqrestore(&gVmbusConnection.channelmsg_lock, flags);
 123
 124         DPRINT_DBG(VMBUS, "Vmbus connection - interrupt pfn %llx, "
 125                    "monitor1 pfn %llx,, monitor2 pfn %llx",
 126                    msg->interrupt_page, msg->monitor_page1, msg->monitor_page2);
 127
 128         DPRINT_DBG(VMBUS, "Sending channel initiate msg...");
 129         ret = VmbusPostMessage(msg,
 130                                sizeof(struct vmbus_channel_initiate_contact));
 131         if (ret != 0) {
 132                 list_del(&msgInfo->msglistentry);
 133                 goto Cleanup;
 134         }
 135
 136         /* Wait for the connection response */
 137         osd_waitevent_wait(msgInfo->waitevent);
 138
 139         list_del(&msgInfo->msglistentry);
 140
 141         /* Check if successful */
 142         if (msgInfo->response.version_response.version_supported) {
 143                 DPRINT_INFO(VMBUS, "Vmbus connected!!");
 144                 gVmbusConnection.ConnectState = Connected;
 145
 146         } else {
 147                 DPRINT_ERR(VMBUS, "Vmbus connection failed!!..."
 148                            "current version (%d) not supported",
 149                            VMBUS_REVISION_NUMBER);
 150                 ret = -1;
 151                 goto Cleanup;
 152         }
 153
 154         kfree(msgInfo->waitevent);
 155         kfree(msgInfo);
 156         return 0;
 157
 158 Cleanup:
 159         gVmbusConnection.ConnectState = Disconnected;
 160
 161         if (gVmbusConnection.WorkQueue)
 162                 destroy_workqueue(gVmbusConnection.WorkQueue);
 163
 164         if (gVmbusConnection.InterruptPage) {
 165                 osd_page_free(gVmbusConnection.InterruptPage, 1);
 166                 gVmbusConnection.InterruptPage = NULL;
 167         }
 168
 169         if (gVmbusConnection.MonitorPages) {
 170                 osd_page_free(gVmbusConnection.MonitorPages, 2);
 171                 gVmbusConnection.MonitorPages = NULL;
 172         }
 173
 174         if (msgInfo) {
 175                 kfree(msgInfo->waitevent);
 176                 kfree(msgInfo);
 177         }
 178
 179         return ret;
 180 }
 181
 182 /*
 183  * VmbusDisconnect - Sends a disconnect request on the partition service connection
 184  */
 185 int VmbusDisconnect(void)
 186 {
 187         int ret = 0;
 188         struct vmbus_channel_message_header *msg;
 189
 190         /* Make sure we are connected */
 191         if (gVmbusConnection.ConnectState != Connected)
 192                 return -1;
 193
 194         msg = kzalloc(sizeof(struct vmbus_channel_message_header), GFP_KERNEL);
 195         if (!msg)
 196                 return -ENOMEM;
 197
 198         msg->msgtype = CHANNELMSG_UNLOAD;
 199
 200         ret = VmbusPostMessage(msg,
 201                                sizeof(struct vmbus_channel_message_header));
 202         if (ret != 0)
 203                 goto Cleanup;
 204
 205         osd_page_free(gVmbusConnection.InterruptPage, 1);
 206
 207         /* TODO: iterate thru the msg list and free up */
 208         destroy_workqueue(gVmbusConnection.WorkQueue);
 209
 210         gVmbusConnection.ConnectState = Disconnected;
 211
 212         DPRINT_INFO(VMBUS, "Vmbus disconnected!!");
 213
 214 Cleanup:
 215         kfree(msg);
 216         return ret;
 217 }
 218
 219 /*
 220  * GetChannelFromRelId - Get the channel object given its child relative id (ie channel id)
 221  */
 222 struct vmbus_channel *GetChannelFromRelId(u32 relId)
 223 {
 224         struct vmbus_channel *channel;
 225         struct vmbus_channel *foundChannel  = NULL;
 226         unsigned long flags;
 227
 228         spin_lock_irqsave(&gVmbusConnection.channel_lock, flags);
 229         list_for_each_entry(channel, &gVmbusConnection.ChannelList, listentry) {
 230                 if (channel->offermsg.child_relid == relId) {
 231                         foundChannel = channel;
 232                         break;
 233                 }
 234         }
 235         spin_unlock_irqrestore(&gVmbusConnection.channel_lock, flags);
 236
 237         return foundChannel;
 238 }
 239
 240 /*
 241  * VmbusProcessChannelEvent - Process a channel event notification
 242  */
 243 static void VmbusProcessChannelEvent(void *context)
 244 {
 245         struct vmbus_channel *channel;
 246         u32 relId = (u32)(unsigned long)context;
 247
 248         /* ASSERT(relId > 0); */
 249
 250         /*
 251          * Find the channel based on this relid and invokes the
 252          * channel callback to process the event
 253          */
 254         channel = GetChannelFromRelId(relId);
 255
 256         if (channel) {
 257                 vmbus_onchannel_event(channel);
 258                 /*
 259                  * WorkQueueQueueWorkItem(channel->dataWorkQueue,
 260                  *                        vmbus_onchannel_event,
 261                  *                        (void*)channel);
 262                  */
 263         } else {
 264                 DPRINT_ERR(VMBUS, "channel not found for relid - %d.", relId);
 265         }
 266 }
 267
 268 /*
 269  * VmbusOnEvents - Handler for events
 270  */
 271 void VmbusOnEvents(void)
 272 {
 273         int dword;
 274         int maxdword = MAX_NUM_CHANNELS_SUPPORTED >> 5;
 275         int bit;
 276         int relid;
 277         u32 *recvInterruptPage = gVmbusConnection.RecvInterruptPage;
 278
 279         /* Check events */
 280         if (recvInterruptPage) {
 281                 for (dword = 0; dword < maxdword; dword++) {
 282                         if (recvInterruptPage[dword]) {
 283                                 for (bit = 0; bit < 32; bit++) {
 284                                         if (test_and_clear_bit(bit, (unsigned long *)&recvInterruptPage[dword])) {
 285                                                 relid = (dword << 5) + bit;
 286                                                 DPRINT_DBG(VMBUS, "event detected for relid - %d", relid);
 287
 288                                                 if (relid == 0) {
 289                                                         /* special case - vmbus channel protocol msg */
 290                                                         DPRINT_DBG(VMBUS, "invalid relid - %d", relid);
 291                                                         continue;
 292                                                 } else {
 293                                                         /* QueueWorkItem(VmbusProcessEvent, (void*)relid); */
 294                                                         /* ret = WorkQueueQueueWorkItem(gVmbusConnection.workQueue, VmbusProcessChannelEvent, (void*)relid); */
 295                                                         VmbusProcessChannelEvent((void *)(unsigned long)relid);
 296                                                 }
 297                                         }
 298                                 }
 299                         }
 300                  }
 301         }
 302         return;
 303 }
 304
 305 /*
 306  * VmbusPostMessage - Send a msg on the vmbus's message connection
 307  */
 308 int VmbusPostMessage(void *buffer, size_t bufferLen)
 309 {
 310         union hv_connection_id connId;
 311
 312         connId.asu32 = 0;
 313         connId.u.id = VMBUS_MESSAGE_CONNECTION_ID;
 314         return hv_post_message(connId, 1, buffer, bufferLen);
 315 }
 316
 317 /*
 318  * VmbusSetEvent - Send an event notification to the parent
 319  */
 320 int VmbusSetEvent(u32 childRelId)
 321 {
 322         /* Each u32 represents 32 channels */
 323         set_bit(childRelId & 31,
 324                 (unsigned long *)gVmbusConnection.SendInterruptPage +
 325                 (childRelId >> 5));
 326
 327         return hv_signal_event();
 328 }