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 #include <linux/kernel.h>
  23 #include <linux/mm.h>
  24 #include "osd.h"
  25 #include "StorVsc.c"
  26
  27 static const char *gBlkDriverName = "blkvsc";
  28
  29 /* {32412632-86cb-44a2-9b5c-50d1417354f5} */
  30 static const struct hv_guid gBlkVscDeviceType = {
  31         .data = {
  32                 0x32, 0x26, 0x41, 0x32, 0xcb, 0x86, 0xa2, 0x44,
  33                 0x9b, 0x5c, 0x50, 0xd1, 0x41, 0x73, 0x54, 0xf5
  34         }
  35 };
  36
  37 static int BlkVscOnDeviceAdd(struct hv_device *Device, void *AdditionalInfo)
  38 {
  39         struct storvsc_device_info *deviceInfo;
  40         int ret = 0;
  41
  42         DPRINT_ENTER(BLKVSC);
  43
  44         deviceInfo = (struct storvsc_device_info *)AdditionalInfo;
  45
  46         ret = StorVscOnDeviceAdd(Device, AdditionalInfo);
  47         if (ret != 0) {
  48                 DPRINT_EXIT(BLKVSC);
  49                 return ret;
  50         }
  51
  52         /*
  53          * We need to use the device instance guid to set the path and target
  54          * id. For IDE devices, the device instance id is formatted as
  55          * <bus id> * - <device id> - 8899 - 000000000000.
  56          */
  57         deviceInfo->PathId = Device->deviceInstance.data[3] << 24 |
  58                              Device->deviceInstance.data[2] << 16 |
  59                              Device->deviceInstance.data[1] << 8  |
  60                              Device->deviceInstance.data[0];
  61
  62         deviceInfo->TargetId = Device->deviceInstance.data[5] << 8 |
  63                                Device->deviceInstance.data[4];
  64
  65         DPRINT_EXIT(BLKVSC);
  66
  67         return ret;
  68 }
  69
  70 int BlkVscInitialize(struct hv_driver *Driver)
  71 {
  72         struct storvsc_driver_object *storDriver;
  73         int ret = 0;
  74
  75         DPRINT_ENTER(BLKVSC);
  76
  77         storDriver = (struct storvsc_driver_object *)Driver;
  78
  79         /* Make sure we are at least 2 pages since 1 page is used for control */
  80         ASSERT(storDriver->RingBufferSize >= (PAGE_SIZE << 1));
  81
  82         Driver->name = gBlkDriverName;
  83         memcpy(&Driver->deviceType, &gBlkVscDeviceType, sizeof(struct hv_guid));
  84
  85         storDriver->RequestExtSize = sizeof(struct storvsc_request_extension);
  86
  87         /*
  88          * Divide the ring buffer data size (which is 1 page less than the ring
  89          * buffer size since that page is reserved for the ring buffer indices)
  90          * by the max request size (which is
  91          * VMBUS_CHANNEL_PACKET_MULITPAGE_BUFFER + struct vstor_packet + u64)
  92          */
  93         storDriver->MaxOutstandingRequestsPerChannel =
  94                 ((storDriver->RingBufferSize - PAGE_SIZE) /
  95                   ALIGN_UP(MAX_MULTIPAGE_BUFFER_PACKET +
  96                            sizeof(struct vstor_packet) + sizeof(u64),
  97                            sizeof(u64)));
  98
  99         DPRINT_INFO(BLKVSC, "max io outstd %u",
 100                     storDriver->MaxOutstandingRequestsPerChannel);
 101
 102         /* Setup the dispatch table */
 103         storDriver->Base.OnDeviceAdd = BlkVscOnDeviceAdd;
 104         storDriver->Base.OnDeviceRemove = StorVscOnDeviceRemove;
 105         storDriver->Base.OnCleanup = StorVscOnCleanup;
 106         storDriver->OnIORequest = StorVscOnIORequest;
 107
 108         DPRINT_EXIT(BLKVSC);
 109
 110         return ret;
 111 }