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         DPRINT_ENTER(VMBUS);
  48
  49         /* Make sure we are not connecting or connected */
  50         if (gVmbusConnection.ConnectState != Disconnected)
  51                 return -1;
  52
  53         /* Initialize the vmbus connection */
  54         gVmbusConnection.ConnectState = Connecting;
  55         gVmbusConnection.WorkQueue = create_workqueue("hv_vmbus_con");
  56         if (!gVmbusConnection.WorkQueue) {
  57                 ret = -1;
  58                 goto Cleanup;
  59         }
  60
  61         INIT_LIST_HEAD(&gVmbusConnection.ChannelMsgList);
  62         spin_lock_init(&gVmbusConnection.channelmsg_lock);
  63
  64         INIT_LIST_HEAD(&gVmbusConnection.ChannelList);
  65         spin_lock_init(&gVmbusConnection.channel_lock);
  66
  67         /*
  68          * Setup the vmbus event connection for channel interrupt
  69          * abstraction stuff
  70          */
  71         gVmbusConnection.InterruptPage = osd_PageAlloc(1);
  72         if (gVmbusConnection.InterruptPage == NULL) {
  73                 ret = -1;
  74                 goto Cleanup;
  75         }
  76
  77         gVmbusConnection.RecvInterruptPage = gVmbusConnection.InterruptPage;
  78         gVmbusConnection.SendInterruptPage =
  79                 (void *)((unsigned long)gVmbusConnection.InterruptPage +
  80                         (PAGE_SIZE >> 1));
  81
  82         /*
  83          * Setup the monitor notification facility. The 1st page for
  84          * parent->child and the 2nd page for child->parent
  85          */
  86         gVmbusConnection.MonitorPages = osd_PageAlloc(2);
  87         if (gVmbusConnection.MonitorPages == NULL) {
  88                 ret = -1;
  89                 goto Cleanup;
  90         }
  91
  92         msgInfo = kzalloc(sizeof(*msgInfo) +
  93                           sizeof(struct vmbus_channel_initiate_contact),
  94                           GFP_KERNEL);
  95         if (msgInfo == NULL) {
  96                 ret = -ENOMEM;
  97                 goto Cleanup;
  98         }
  99
 100         msgInfo->WaitEvent = osd_WaitEventCreate();
 101         if (!msgInfo->WaitEvent) {
 102                 ret = -ENOMEM;
 103                 goto Cleanup;
 104         }
 105
 106         msg = (struct vmbus_channel_initiate_contact *)msgInfo->Msg;
 107
 108         msg->Header.MessageType = ChannelMessageInitiateContact;
 109         msg->VMBusVersionRequested = VMBUS_REVISION_NUMBER;
 110         msg->InterruptPage = virt_to_phys(gVmbusConnection.InterruptPage);
 111         msg->MonitorPage1 = virt_to_phys(gVmbusConnection.MonitorPages);
 112         msg->MonitorPage2 = virt_to_phys(
 113                         (void *)((unsigned long)gVmbusConnection.MonitorPages +
 114                                  PAGE_SIZE));
 115
 116         /*
 117          * Add to list before we send the request since we may
 118          * receive the response before returning from this routine
 119          */
 120         spin_lock_irqsave(&gVmbusConnection.channelmsg_lock, flags);
 121         list_add_tail(&msgInfo->MsgListEntry,
 122                       &gVmbusConnection.ChannelMsgList);
 123
 124         spin_unlock_irqrestore(&gVmbusConnection.channelmsg_lock, flags);
 125
 126         DPRINT_DBG(VMBUS, "Vmbus connection - interrupt pfn %llx, "
 127                    "monitor1 pfn %llx,, monitor2 pfn %llx",
 128                    msg->InterruptPage, msg->MonitorPage1, msg->MonitorPage2);
 129
 130         DPRINT_DBG(VMBUS, "Sending channel initiate msg...");
 131         ret = VmbusPostMessage(msg,
 132                                sizeof(struct vmbus_channel_initiate_contact));
 133         if (ret != 0) {
 134                 list_del(&msgInfo->MsgListEntry);
 135                 goto Cleanup;
 136         }
 137
 138         /* Wait for the connection response */
 139         osd_WaitEventWait(msgInfo->WaitEvent);
 140
 141         list_del(&msgInfo->MsgListEntry);
 142
 143         /* Check if successful */
 144         if (msgInfo->Response.VersionResponse.VersionSupported) {
 145                 DPRINT_INFO(VMBUS, "Vmbus connected!!");
 146                 gVmbusConnection.ConnectState = Connected;
 147
 148         } else {
 149                 DPRINT_ERR(VMBUS, "Vmbus connection failed!!..."
 150                            "current version (%d) not supported",
 151                            VMBUS_REVISION_NUMBER);
 152                 ret = -1;
 153                 goto Cleanup;
 154         }
 155
 156         kfree(msgInfo->WaitEvent);
 157         kfree(msgInfo);
 158         DPRINT_EXIT(VMBUS);
 159
 160         return 0;
 161
 162 Cleanup:
 163         gVmbusConnection.ConnectState = Disconnected;
 164
 165         if (gVmbusConnection.WorkQueue)
 166                 destroy_workqueue(gVmbusConnection.WorkQueue);
 167
 168         if (gVmbusConnection.InterruptPage) {
 169                 osd_PageFree(gVmbusConnection.InterruptPage, 1);
 170                 gVmbusConnection.InterruptPage = NULL;
 171         }
 172
 173         if (gVmbusConnection.MonitorPages) {
 174                 osd_PageFree(gVmbusConnection.MonitorPages, 2);
 175                 gVmbusConnection.MonitorPages = NULL;
 176         }
 177
 178         if (msgInfo) {
 179                 kfree(msgInfo->WaitEvent);
 180                 kfree(msgInfo);
 181         }
 182
 183         DPRINT_EXIT(VMBUS);
 184
 185         return ret;
 186 }
 187
 188 /*
 189  * VmbusDisconnect - Sends a disconnect request on the partition service connection
 190  */
 191 int VmbusDisconnect(void)
 192 {
 193         int ret = 0;
 194         struct vmbus_channel_message_header *msg;
 195
 196         DPRINT_ENTER(VMBUS);
 197
 198         /* Make sure we are connected */
 199         if (gVmbusConnection.ConnectState != Connected)
 200                 return -1;
 201
 202         msg = kzalloc(sizeof(struct vmbus_channel_message_header), GFP_KERNEL);
 203         if (!msg)
 204                 return -ENOMEM;
 205
 206         msg->MessageType = ChannelMessageUnload;
 207
 208         ret = VmbusPostMessage(msg,
 209                                sizeof(struct vmbus_channel_message_header));
 210         if (ret != 0)
 211                 goto Cleanup;
 212
 213         osd_PageFree(gVmbusConnection.InterruptPage, 1);
 214
 215         /* TODO: iterate thru the msg list and free up */
 216         destroy_workqueue(gVmbusConnection.WorkQueue);
 217
 218         gVmbusConnection.ConnectState = Disconnected;
 219
 220         DPRINT_INFO(VMBUS, "Vmbus disconnected!!");
 221
 222 Cleanup:
 223         kfree(msg);
 224         DPRINT_EXIT(VMBUS);
 225         return ret;
 226 }
 227
 228 /*
 229  * GetChannelFromRelId - Get the channel object given its child relative id (ie channel id)
 230  */
 231 struct vmbus_channel *GetChannelFromRelId(u32 relId)
 232 {
 233         struct vmbus_channel *channel;
 234         struct vmbus_channel *foundChannel  = NULL;
 235         unsigned long flags;
 236
 237         spin_lock_irqsave(&gVmbusConnection.channel_lock, flags);
 238         list_for_each_entry(channel, &gVmbusConnection.ChannelList, ListEntry) {
 239                 if (channel->OfferMsg.ChildRelId == relId) {
 240                         foundChannel = channel;
 241                         break;
 242                 }
 243         }
 244         spin_unlock_irqrestore(&gVmbusConnection.channel_lock, flags);
 245
 246         return foundChannel;
 247 }
 248
 249 /*
 250  * VmbusProcessChannelEvent - Process a channel event notification
 251  */
 252 static void VmbusProcessChannelEvent(void *context)
 253 {
 254         struct vmbus_channel *channel;
 255         u32 relId = (u32)(unsigned long)context;
 256
 257         /* ASSERT(relId > 0); */
 258
 259         /*
 260          * Find the channel based on this relid and invokes the
 261          * channel callback to process the event
 262          */
 263         channel = GetChannelFromRelId(relId);
 264
 265         if (channel) {
 266                 VmbusChannelOnChannelEvent(channel);
 267                 /*
 268                  * WorkQueueQueueWorkItem(channel->dataWorkQueue,
 269                  *                        VmbusChannelOnChannelEvent,
 270                  *                        (void*)channel);
 271                  */
 272         } else {
 273                 DPRINT_ERR(VMBUS, "channel not found for relid - %d.", relId);
 274         }
 275 }
 276
 277 /*
 278  * VmbusOnEvents - Handler for events
 279  */
 280 void VmbusOnEvents(void)
 281 {
 282         int dword;
 283         int maxdword = MAX_NUM_CHANNELS_SUPPORTED >> 5;
 284         int bit;
 285         int relid;
 286         u32 *recvInterruptPage = gVmbusConnection.RecvInterruptPage;
 287
 288         DPRINT_ENTER(VMBUS);
 289
 290         /* Check events */
 291         if (recvInterruptPage) {
 292                 for (dword = 0; dword < maxdword; dword++) {
 293                         if (recvInterruptPage[dword]) {
 294                                 for (bit = 0; bit < 32; bit++) {
 295                                         if (test_and_clear_bit(bit, (unsigned long *)&recvInterruptPage[dword])) {
 296                                                 relid = (dword << 5) + bit;
 297                                                 DPRINT_DBG(VMBUS, "event detected for relid - %d", relid);
 298
 299                                                 if (relid == 0) {
 300                                                         /* special case - vmbus channel protocol msg */
 301                                                         DPRINT_DBG(VMBUS, "invalid relid - %d", relid);
 302                                                         continue;
 303                                                 } else {
 304                                                         /* QueueWorkItem(VmbusProcessEvent, (void*)relid); */
 305                                                         /* ret = WorkQueueQueueWorkItem(gVmbusConnection.workQueue, VmbusProcessChannelEvent, (void*)relid); */
 306                                                         VmbusProcessChannelEvent((void *)(unsigned long)relid);
 307                                                 }
 308                                         }
 309                                 }
 310                         }
 311                  }
 312         }
 313         DPRINT_EXIT(VMBUS);
 314
 315         return;
 316 }
 317
 318 /*
 319  * VmbusPostMessage - Send a msg on the vmbus's message connection
 320  */
 321 int VmbusPostMessage(void *buffer, size_t bufferLen)
 322 {
 323         union hv_connection_id connId;
 324
 325         connId.Asu32 = 0;
 326         connId.u.Id = VMBUS_MESSAGE_CONNECTION_ID;
 327         return HvPostMessage(connId, 1, buffer, bufferLen);
 328 }
 329
 330 /*
 331  * VmbusSetEvent - Send an event notification to the parent
 332  */
 333 int VmbusSetEvent(u32 childRelId)
 334 {
 335         int ret = 0;
 336
 337         DPRINT_ENTER(VMBUS);
 338
 339         /* Each u32 represents 32 channels */
 340         set_bit(childRelId & 31,
 341                 (unsigned long *)gVmbusConnection.SendInterruptPage +
 342                 (childRelId >> 5));
 343
 344         ret = HvSignalEvent();
 345
 346         DPRINT_EXIT(VMBUS);
 347
 348         return ret;
 349 }