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/sched.h>
  25 #include <linux/wait.h>
  26 #include <linux/mm.h>
  27 #include <linux/slab.h>
  28 #include <linux/vmalloc.h>
  29 #include "hv_api.h"
  30 #include "logging.h"
  31 #include "vmbus_private.h"
  32
  33
  34 struct vmbus_connection vmbus_connection = {
  35         .conn_state             = DISCONNECTED,
  36         .next_gpadl_handle      = ATOMIC_INIT(0xE1E10),
  37 };
  38
  39 /*
  40  * vmbus_connect - Sends a connect request on the partition service connection
  41  */
  42 int vmbus_connect(void)
  43 {
  44         int ret = 0;
  45         struct vmbus_channel_msginfo *msginfo = NULL;
  46         struct vmbus_channel_initiate_contact *msg;
  47         unsigned long flags;
  48
  49         /* Make sure we are not connecting or connected */
  50         if (vmbus_connection.conn_state != DISCONNECTED)
  51                 return -1;
  52
  53         /* Initialize the vmbus connection */
  54         vmbus_connection.conn_state = CONNECTING;
  55         vmbus_connection.work_queue = create_workqueue("hv_vmbus_con");
  56         if (!vmbus_connection.work_queue) {
  57                 ret = -1;
  58                 goto Cleanup;
  59         }
  60
  61         INIT_LIST_HEAD(&vmbus_connection.chn_msg_list);
  62         spin_lock_init(&vmbus_connection.channelmsg_lock);
  63
  64         INIT_LIST_HEAD(&vmbus_connection.chn_list);
  65         spin_lock_init(&vmbus_connection.channel_lock);
  66
  67         /*
  68          * Setup the vmbus event connection for channel interrupt
  69          * abstraction stuff
  70          */
  71         vmbus_connection.int_page =
  72         (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, 0);
  73         if (vmbus_connection.int_page == NULL) {
  74                 ret = -1;
  75                 goto Cleanup;
  76         }
  77
  78         vmbus_connection.recv_int_page = vmbus_connection.int_page;
  79         vmbus_connection.send_int_page =
  80                 (void *)((unsigned long)vmbus_connection.int_page +
  81                         (PAGE_SIZE >> 1));
  82
  83         /*
  84          * Setup the monitor notification facility. The 1st page for
  85          * parent->child and the 2nd page for child->parent
  86          */
  87         vmbus_connection.monitor_pages =
  88         (void *)__get_free_pages((GFP_KERNEL|__GFP_ZERO), 1);
  89         if (vmbus_connection.monitor_pages == NULL) {
  90                 ret = -1;
  91                 goto Cleanup;
  92         }
  93
  94         msginfo = kzalloc(sizeof(*msginfo) +
  95                           sizeof(struct vmbus_channel_initiate_contact),
  96                           GFP_KERNEL);
  97         if (msginfo == NULL) {
  98                 ret = -ENOMEM;
  99                 goto Cleanup;
 100         }
 101
 102         init_waitqueue_head(&msginfo->waitevent);
 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(vmbus_connection.int_page);
 109         msg->monitor_page1 = virt_to_phys(vmbus_connection.monitor_pages);
 110         msg->monitor_page2 = virt_to_phys(
 111                         (void *)((unsigned long)vmbus_connection.monitor_pages +
 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(&vmbus_connection.channelmsg_lock, flags);
 119         list_add_tail(&msginfo->msglistentry,
 120                       &vmbus_connection.chn_msg_list);
 121
 122         spin_unlock_irqrestore(&vmbus_connection.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 = vmbus_post_msg(msg,
 130                                sizeof(struct vmbus_channel_initiate_contact));
 131         if (ret != 0) {
 132                 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 133                 list_del(&msginfo->msglistentry);
 134                 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock,
 135                                         flags);
 136                 goto Cleanup;
 137         }
 138
 139         /* Wait for the connection response */
 140         msginfo->wait_condition = 0;
 141         wait_event_timeout(msginfo->waitevent, msginfo->wait_condition,
 142                         msecs_to_jiffies(1000));
 143         if (msginfo->wait_condition == 0) {
 144                 spin_lock_irqsave(&vmbus_connection.channelmsg_lock,
 145                                 flags);
 146                 list_del(&msginfo->msglistentry);
 147                 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock,
 148                                         flags);
 149                 ret = -ETIMEDOUT;
 150                 goto Cleanup;
 151         }
 152
 153         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 154         list_del(&msginfo->msglistentry);
 155         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 156
 157         /* Check if successful */
 158         if (msginfo->response.version_response.version_supported) {
 159                 DPRINT_INFO(VMBUS, "Vmbus connected!!");
 160                 vmbus_connection.conn_state = CONNECTED;
 161
 162         } else {
 163                 DPRINT_ERR(VMBUS, "Vmbus connection failed!!..."
 164                            "current version (%d) not supported",
 165                            VMBUS_REVISION_NUMBER);
 166                 ret = -1;
 167                 goto Cleanup;
 168         }
 169
 170         kfree(msginfo);
 171         return 0;
 172
 173 Cleanup:
 174         vmbus_connection.conn_state = DISCONNECTED;
 175
 176         if (vmbus_connection.work_queue)
 177                 destroy_workqueue(vmbus_connection.work_queue);
 178
 179         if (vmbus_connection.int_page) {
 180                 free_pages((unsigned long)vmbus_connection.int_page, 0);
 181                 vmbus_connection.int_page = NULL;
 182         }
 183
 184         if (vmbus_connection.monitor_pages) {
 185                 free_pages((unsigned long)vmbus_connection.monitor_pages, 1);
 186                 vmbus_connection.monitor_pages = NULL;
 187         }
 188
 189         kfree(msginfo);
 190
 191         return ret;
 192 }
 193
 194 /*
 195  * vmbus_disconnect -
 196  * Sends a disconnect request on the partition service connection
 197  */
 198 int vmbus_disconnect(void)
 199 {
 200         int ret = 0;
 201         struct vmbus_channel_message_header *msg;
 202
 203         /* Make sure we are connected */
 204         if (vmbus_connection.conn_state != CONNECTED)
 205                 return -1;
 206
 207         msg = kzalloc(sizeof(struct vmbus_channel_message_header), GFP_KERNEL);
 208         if (!msg)
 209                 return -ENOMEM;
 210
 211         msg->msgtype = CHANNELMSG_UNLOAD;
 212
 213         ret = vmbus_post_msg(msg,
 214                                sizeof(struct vmbus_channel_message_header));
 215         if (ret != 0)
 216                 goto Cleanup;
 217
 218         free_pages((unsigned long)vmbus_connection.int_page, 0);
 219         free_pages((unsigned long)vmbus_connection.monitor_pages, 1);
 220
 221         /* TODO: iterate thru the msg list and free up */
 222         destroy_workqueue(vmbus_connection.work_queue);
 223
 224         vmbus_connection.conn_state = DISCONNECTED;
 225
 226         DPRINT_INFO(VMBUS, "Vmbus disconnected!!");
 227
 228 Cleanup:
 229         kfree(msg);
 230         return ret;
 231 }
 232
 233 /*
 234  * relid2channel - Get the channel object given its
 235  * child relative id (ie channel id)
 236  */
 237 struct vmbus_channel *relid2channel(u32 relid)
 238 {
 239         struct vmbus_channel *channel;
 240         struct vmbus_channel *found_channel  = NULL;
 241         unsigned long flags;
 242
 243         spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
 244         list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
 245                 if (channel->offermsg.child_relid == relid) {
 246                         found_channel = channel;
 247                         break;
 248                 }
 249         }
 250         spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
 251
 252         return found_channel;
 253 }
 254
 255 /*
 256  * process_chn_event - Process a channel event notification
 257  */
 258 static void process_chn_event(void *context)
 259 {
 260         struct vmbus_channel *channel;
 261         u32 relid = (u32)(unsigned long)context;
 262
 263         /* ASSERT(relId > 0); */
 264
 265         /*
 266          * Find the channel based on this relid and invokes the
 267          * channel callback to process the event
 268          */
 269         channel = relid2channel(relid);
 270
 271         if (channel) {
 272                 vmbus_onchannel_event(channel);
 273                 /*
 274                  * WorkQueueQueueWorkItem(channel->dataWorkQueue,
 275                  *                        vmbus_onchannel_event,
 276                  *                        (void*)channel);
 277                  */
 278         } else {
 279                 DPRINT_ERR(VMBUS, "channel not found for relid - %d.", relid);
 280         }
 281 }
 282
 283 /*
 284  * vmbus_on_event - Handler for events
 285  */
 286 void vmbus_on_event(unsigned long data)
 287 {
 288         int dword;
 289         int maxdword = MAX_NUM_CHANNELS_SUPPORTED >> 5;
 290         int bit;
 291         int relid;
 292         u32 *recv_int_page = vmbus_connection.recv_int_page;
 293
 294         /* Check events */
 295         if (recv_int_page) {
 296                 for (dword = 0; dword < maxdword; dword++) {
 297                         if (recv_int_page[dword]) {
 298                                 for (bit = 0; bit < 32; bit++) {
 299                                         if (test_and_clear_bit(bit,
 300                                                 (unsigned long *)
 301                                                 &recv_int_page[dword])) {
 302                                                 relid = (dword << 5) + bit;
 303                                                 DPRINT_DBG(VMBUS, "event detected for relid - %d", relid);
 304
 305                                                 if (relid == 0) {
 306                                                         /* special case - vmbus channel protocol msg */
 307                                                         DPRINT_DBG(VMBUS, "invalid relid - %d", relid);
 308                                                         continue;
 309                                                 } else {
 310                                                         /* QueueWorkItem(VmbusProcessEvent, (void*)relid); */
 311                                                         /* ret = WorkQueueQueueWorkItem(gVmbusConnection.workQueue, VmbusProcessChannelEvent, (void*)relid); */
 312                                                 process_chn_event((void *)
 313                                                 (unsigned long)relid);
 314                                                 }
 315                                         }
 316                                 }
 317                         }
 318                  }
 319         }
 320         return;
 321 }
 322
 323 /*
 324  * vmbus_post_msg - Send a msg on the vmbus's message connection
 325  */
 326 int vmbus_post_msg(void *buffer, size_t buflen)
 327 {
 328         union hv_connection_id conn_id;
 329
 330         conn_id.asu32 = 0;
 331         conn_id.u.id = VMBUS_MESSAGE_CONNECTION_ID;
 332         return hv_post_message(conn_id, 1, buffer, buflen);
 333 }
 334
 335 /*
 336  * vmbus_set_event - Send an event notification to the parent
 337  */
 338 int vmbus_set_event(u32 child_relid)
 339 {
 340         /* Each u32 represents 32 channels */
 341         set_bit(child_relid & 31,
 342                 (unsigned long *)vmbus_connection.send_int_page +
 343                 (child_relid >> 5));
 344
 345         return hv_signal_event();
 346 }