drivers/staging/hv/BlkVsc.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  *   Hank Janssen  <hjanssen@microsoft.com>
  20  *
  21  */
  22
  23 #include <linux/kernel.h>
  24 #include <linux/mm.h>
  25 #include "StorVsc.c"
  26
  27 static const char* gBlkDriverName="blkvsc";
  28
  29 /* {32412632-86cb-44a2-9b5c-50d1417354f5} */
  30 static const GUID gBlkVscDeviceType={
  31         .Data = {0x32, 0x26, 0x41, 0x32, 0xcb, 0x86, 0xa2, 0x44, 0x9b, 0x5c, 0x50, 0xd1, 0x41, 0x73, 0x54, 0xf5}
  32 };
  33
  34 /* Static routines */
  35 static int
  36 BlkVscOnDeviceAdd(
  37         struct hv_device *Device,
  38         void                    *AdditionalInfo
  39         );
  40
  41
  42 int
  43 BlkVscInitialize(
  44         DRIVER_OBJECT *Driver
  45         )
  46 {
  47         STORVSC_DRIVER_OBJECT* storDriver = (STORVSC_DRIVER_OBJECT*)Driver;
  48         int ret=0;
  49
  50         DPRINT_ENTER(BLKVSC);
  51
  52         /* Make sure we are at least 2 pages since 1 page is used for control */
  53         ASSERT(storDriver->RingBufferSize >= (PAGE_SIZE << 1));
  54
  55         Driver->name = gBlkDriverName;
  56         memcpy(&Driver->deviceType, &gBlkVscDeviceType, sizeof(GUID));
  57
  58         storDriver->RequestExtSize                      = sizeof(STORVSC_REQUEST_EXTENSION);
  59         /* Divide the ring buffer data size (which is 1 page less than the ring buffer size since that page is reserved for the ring buffer indices) */
  60         /* by the max request size (which is VMBUS_CHANNEL_PACKET_MULITPAGE_BUFFER + VSTOR_PACKET + u64) */
  61         storDriver->MaxOutstandingRequestsPerChannel =
  62                 ((storDriver->RingBufferSize - PAGE_SIZE) / ALIGN_UP(MAX_MULTIPAGE_BUFFER_PACKET + sizeof(VSTOR_PACKET) + sizeof(u64),sizeof(u64)));
  63
  64         DPRINT_INFO(BLKVSC, "max io outstd %u", storDriver->MaxOutstandingRequestsPerChannel);
  65
  66         /* Setup the dispatch table */
  67         storDriver->Base.OnDeviceAdd            = BlkVscOnDeviceAdd;
  68         storDriver->Base.OnDeviceRemove         = StorVscOnDeviceRemove;
  69         storDriver->Base.OnCleanup                      = StorVscOnCleanup;
  70
  71         storDriver->OnIORequest                         = StorVscOnIORequest;
  72
  73         DPRINT_EXIT(BLKVSC);
  74
  75         return ret;
  76 }
  77
  78 int
  79 BlkVscOnDeviceAdd(
  80         struct hv_device *Device,
  81         void                    *AdditionalInfo
  82         )
  83 {
  84         int ret=0;
  85         STORVSC_DEVICE_INFO *deviceInfo = (STORVSC_DEVICE_INFO*)AdditionalInfo;
  86
  87         DPRINT_ENTER(BLKVSC);
  88
  89         ret = StorVscOnDeviceAdd(Device, AdditionalInfo);
  90
  91         if (ret != 0)
  92         {
  93                 DPRINT_EXIT(BLKVSC);
  94
  95                 return ret;
  96         }
  97
  98         /* We need to use the device instance guid to set the path and target id. For IDE devices, the */
  99         /* device instance id is formatted as <bus id> - <device id> - 8899 - 000000000000. */
 100         deviceInfo->PathId = Device->deviceInstance.Data[3] << 24 | Device->deviceInstance.Data[2] << 16 |
 101                 Device->deviceInstance.Data[1] << 8 |Device->deviceInstance.Data[0];
 102
 103         deviceInfo->TargetId = Device->deviceInstance.Data[5] << 8 | Device->deviceInstance.Data[4];
 104
 105         DPRINT_EXIT(BLKVSC);
 106
 107         return ret;
 108 }