SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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/vmalloc.h>
  26 #include "osd.h"
  27 #include "logging.h"
  28 #include "VmbusPrivate.h"
  29
  30
  31 struct VMBUS_CONNECTION gVmbusConnection = {
  32         .ConnectState           = Disconnected,
  33         .NextGpadlHandle        = ATOMIC_INIT(0xE1E10),
  34 };
  35
  36 /**
  37  * VmbusConnect - Sends a connect request on the partition service connection
  38  */
  39 int VmbusConnect(void)
  40 {
  41         int ret = 0;
  42         struct vmbus_channel_msginfo *msgInfo = NULL;
  43         struct vmbus_channel_initiate_contact *msg;
  44         unsigned long flags;
  45
  46         DPRINT_ENTER(VMBUS);
  47
  48         /* Make sure we are not connecting or connected */
  49         if (gVmbusConnection.ConnectState != Disconnected)
  50                 return -1;
  51
  52         /* Initialize the vmbus connection */
  53         gVmbusConnection.ConnectState = Connecting;
  54         gVmbusConnection.WorkQueue = create_workqueue("hv_vmbus_con");
  55         if (!gVmbusConnection.WorkQueue) {
  56                 ret = -1;
  57                 goto Cleanup;
  58         }
  59
  60         INIT_LIST_HEAD(&gVmbusConnection.ChannelMsgList);
  61         spin_lock_init(&gVmbusConnection.channelmsg_lock);
  62
  63         INIT_LIST_HEAD(&gVmbusConnection.ChannelList);
  64         spin_lock_init(&gVmbusConnection.channel_lock);
  65
  66         /*
  67          * Setup the vmbus event connection for channel interrupt
  68          * abstraction stuff
  69          */
  70         gVmbusConnection.InterruptPage = osd_PageAlloc(1);
  71         if (gVmbusConnection.InterruptPage == NULL) {
  72                 ret = -1;
  73                 goto Cleanup;
  74         }
  75
  76         gVmbusConnection.RecvInterruptPage = gVmbusConnection.InterruptPage;
  77         gVmbusConnection.SendInterruptPage =
  78                 (void *)((unsigned long)gVmbusConnection.InterruptPage +
  79                         (PAGE_SIZE >> 1));
  80
  81         /*
  82          * Setup the monitor notification facility. The 1st page for
  83          * parent->child and the 2nd page for child->parent
  84          */
  85         gVmbusConnection.MonitorPages = osd_PageAlloc(2);
  86         if (gVmbusConnection.MonitorPages == NULL) {
  87                 ret = -1;
  88                 goto Cleanup;
  89         }
  90
  91         msgInfo = kzalloc(sizeof(*msgInfo) +
  92                           sizeof(struct vmbus_channel_initiate_contact),
  93                           GFP_KERNEL);
  94         if (msgInfo == NULL) {
  95                 ret = -1;
  96                 goto Cleanup;
  97         }
  98
  99         msgInfo->WaitEvent = osd_WaitEventCreate();
 100         msg = (struct vmbus_channel_initiate_contact *)msgInfo->Msg;
 101
 102         msg->Header.MessageType = ChannelMessageInitiateContact;
 103         msg->VMBusVersionRequested = VMBUS_REVISION_NUMBER;
 104         msg->InterruptPage = virt_to_phys(gVmbusConnection.InterruptPage);
 105         msg->MonitorPage1 = virt_to_phys(gVmbusConnection.MonitorPages);
 106         msg->MonitorPage2 = virt_to_phys(
 107                         (void *)((unsigned long)gVmbusConnection.MonitorPages +
 108                                  PAGE_SIZE));
 109
 110         /*
 111          * Add to list before we send the request since we may
 112          * receive the response before returning from this routine
 113          */
 114         spin_lock_irqsave(&gVmbusConnection.channelmsg_lock, flags);
 115         list_add_tail(&msgInfo->MsgListEntry,
 116                       &gVmbusConnection.ChannelMsgList);
 117
 118         spin_unlock_irqrestore(&gVmbusConnection.channelmsg_lock, flags);
 119
 120         DPRINT_DBG(VMBUS, "Vmbus connection - interrupt pfn %llx, "
 121                    "monitor1 pfn %llx,, monitor2 pfn %llx",
 122                    msg->InterruptPage, msg->MonitorPage1, msg->MonitorPage2);
 123
 124         DPRINT_DBG(VMBUS, "Sending channel initiate msg...");
 125         ret = VmbusPostMessage(msg,
 126                                sizeof(struct vmbus_channel_initiate_contact));
 127         if (ret != 0) {
 128                 list_del(&msgInfo->MsgListEntry);
 129                 goto Cleanup;
 130         }
 131
 132         /* Wait for the connection response */
 133         osd_WaitEventWait(msgInfo->WaitEvent);
 134
 135         list_del(&msgInfo->MsgListEntry);
 136
 137         /* Check if successful */
 138         if (msgInfo->Response.VersionResponse.VersionSupported) {
 139                 DPRINT_INFO(VMBUS, "Vmbus connected!!");
 140                 gVmbusConnection.ConnectState = Connected;
 141
 142         } else {
 143                 DPRINT_ERR(VMBUS, "Vmbus connection failed!!..."
 144                            "current version (%d) not supported",
 145                            VMBUS_REVISION_NUMBER);
 146                 ret = -1;
 147                 goto Cleanup;
 148         }
 149
 150         kfree(msgInfo->WaitEvent);
 151         kfree(msgInfo);
 152         DPRINT_EXIT(VMBUS);
 153
 154         return 0;
 155
 156 Cleanup:
 157         gVmbusConnection.ConnectState = Disconnected;
 158
 159         if (gVmbusConnection.WorkQueue)
 160                 destroy_workqueue(gVmbusConnection.WorkQueue);
 161
 162         if (gVmbusConnection.InterruptPage) {
 163                 osd_PageFree(gVmbusConnection.InterruptPage, 1);
 164                 gVmbusConnection.InterruptPage = NULL;
 165         }
 166
 167         if (gVmbusConnection.MonitorPages) {
 168                 osd_PageFree(gVmbusConnection.MonitorPages, 2);
 169                 gVmbusConnection.MonitorPages = NULL;
 170         }
 171
 172         if (msgInfo) {
 173                 kfree(msgInfo->WaitEvent);
 174                 kfree(msgInfo);
 175         }
 176
 177         DPRINT_EXIT(VMBUS);
 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         DPRINT_ENTER(VMBUS);
 191
 192         /* Make sure we are connected */
 193         if (gVmbusConnection.ConnectState != Connected)
 194                 return -1;
 195
 196         msg = kzalloc(sizeof(struct vmbus_channel_message_header), GFP_KERNEL);
 197
 198         msg->MessageType = ChannelMessageUnload;
 199
 200         ret = VmbusPostMessage(msg,
 201                                sizeof(struct vmbus_channel_message_header));
 202         if (ret != 0)
 203                 goto Cleanup;
 204
 205         osd_PageFree(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         DPRINT_EXIT(VMBUS);
 217         return ret;
 218 }
 219
 220 /**
 221  * GetChannelFromRelId - Get the channel object given its child relative id (ie channel id)
 222  */
 223 struct vmbus_channel *GetChannelFromRelId(u32 relId)
 224 {
 225         struct vmbus_channel *channel;
 226         struct vmbus_channel *foundChannel  = NULL;
 227         unsigned long flags;
 228
 229         spin_lock_irqsave(&gVmbusConnection.channel_lock, flags);
 230         list_for_each_entry(channel, &gVmbusConnection.ChannelList, ListEntry) {
 231                 if (channel->OfferMsg.ChildRelId == relId) {
 232                         foundChannel = channel;
 233                         break;
 234                 }
 235         }
 236         spin_unlock_irqrestore(&gVmbusConnection.channel_lock, flags);
 237
 238         return foundChannel;
 239 }
 240
 241 /**
 242  * VmbusProcessChannelEvent - Process a channel event notification
 243  */
 244 static void VmbusProcessChannelEvent(void *context)
 245 {
 246         struct vmbus_channel *channel;
 247         u32 relId = (u32)(unsigned long)context;
 248
 249         ASSERT(relId > 0);
 250
 251         /*
 252          * Find the channel based on this relid and invokes the
 253          * channel callback to process the event
 254          */
 255         channel = GetChannelFromRelId(relId);
 256
 257         if (channel) {
 258                 VmbusChannelOnChannelEvent(channel);
 259                 /*
 260                  * WorkQueueQueueWorkItem(channel->dataWorkQueue,
 261                  *                        VmbusChannelOnChannelEvent,
 262                  *                        (void*)channel);
 263                  */
 264         } else {
 265                 DPRINT_ERR(VMBUS, "channel not found for relid - %d.", relId);
 266         }
 267 }
 268
 269 /**
 270  * VmbusOnEvents - Handler for events
 271  */
 272 void VmbusOnEvents(void)
 273 {
 274         int dword;
 275         int maxdword = MAX_NUM_CHANNELS_SUPPORTED >> 5;
 276         int bit;
 277         int relid;
 278         u32 *recvInterruptPage = gVmbusConnection.RecvInterruptPage;
 279
 280         DPRINT_ENTER(VMBUS);
 281
 282         /* Check events */
 283         if (recvInterruptPage) {
 284                 for (dword = 0; dword < maxdword; dword++) {
 285                         if (recvInterruptPage[dword]) {
 286                                 for (bit = 0; bit < 32; bit++) {
 287                                         if (test_and_clear_bit(bit, (unsigned long *)&recvInterruptPage[dword])) {
 288                                                 relid = (dword << 5) + bit;
 289                                                 DPRINT_DBG(VMBUS, "event detected for relid - %d", relid);
 290
 291                                                 if (relid == 0) {
 292                                                         /* special case - vmbus channel protocol msg */
 293                                                         DPRINT_DBG(VMBUS, "invalid relid - %d", relid);
 294                                                         continue;
 295                                                 } else {
 296                                                         /* QueueWorkItem(VmbusProcessEvent, (void*)relid); */
 297                                                         /* ret = WorkQueueQueueWorkItem(gVmbusConnection.workQueue, VmbusProcessChannelEvent, (void*)relid); */
 298                                                         VmbusProcessChannelEvent((void *)(unsigned long)relid);
 299                                                 }
 300                                         }
 301                                 }
 302                         }
 303                  }
 304         }
 305         DPRINT_EXIT(VMBUS);
 306
 307         return;
 308 }
 309
 310 /**
 311  * VmbusPostMessage - Send a msg on the vmbus's message connection
 312  */
 313 int VmbusPostMessage(void *buffer, size_t bufferLen)
 314 {
 315         union hv_connection_id connId;
 316
 317         connId.Asu32 = 0;
 318         connId.u.Id = VMBUS_MESSAGE_CONNECTION_ID;
 319         return HvPostMessage(connId, 1, buffer, bufferLen);
 320 }
 321
 322 /**
 323  * VmbusSetEvent - Send an event notification to the parent
 324  */
 325 int VmbusSetEvent(u32 childRelId)
 326 {
 327         int ret = 0;
 328
 329         DPRINT_ENTER(VMBUS);
 330
 331         /* Each u32 represents 32 channels */
 332         set_bit(childRelId & 31,
 333                 (unsigned long *)gVmbusConnection.SendInterruptPage +
 334                 (childRelId >> 5));
 335
 336         ret = HvSignalEvent();
 337
 338         DPRINT_EXIT(VMBUS);
 339
 340         return ret;
 341 }