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