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    Subject[PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area
    Date
    The storage driver (storvsc_drv.c) handles all block storage devices
    assigned to Linux guests hosted on Hyper-V. This driver has been in the
    staging tree for a while and this patch moves it out of the staging area.
    As per Greg's recommendation, this patch makes no changes to the staging/hv
    directory. Once the driver moves out of staging, we will cleanup the
    staging/hv directory.

    This patch includes all the patches that I have sent against the staging/hv
    tree to address the comments I have gotten to date on this storage driver.


    Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
    ---
    drivers/scsi/Kconfig | 8 +
    drivers/scsi/Makefile | 3 +
    drivers/scsi/storvsc_drv.c | 1567 ++++++++++++++++++++++++++++++++++++++++++++
    3 files changed, 1578 insertions(+), 0 deletions(-)
    create mode 100644 drivers/scsi/storvsc_drv.c

    diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
    index aa573c3..2f72565 100644
    --- a/drivers/scsi/Kconfig
    +++ b/drivers/scsi/Kconfig
    @@ -676,6 +676,14 @@ config VMWARE_PVSCSI
    To compile this driver as a module, choose M here: the
    module will be called vmw_pvscsi.

    +config HYPERV_STORAGE
    + tristate "Microsoft Hyper-V virtual storage driver"
    + depends on SCSI && HYPERV
    + default HYPERV
    + help
    + Select this option to enable the Hyper-V virtual storage driver.
    +
    +
    config LIBFC
    tristate "LibFC module"
    select SCSI_FC_ATTRS
    diff --git a/drivers/scsi/Makefile b/drivers/scsi/Makefile
    index 2b88749..e4c1a69 100644
    --- a/drivers/scsi/Makefile
    +++ b/drivers/scsi/Makefile
    @@ -142,6 +142,7 @@ obj-$(CONFIG_SCSI_BNX2_ISCSI) += libiscsi.o bnx2i/
    obj-$(CONFIG_BE2ISCSI) += libiscsi.o be2iscsi/
    obj-$(CONFIG_SCSI_PMCRAID) += pmcraid.o
    obj-$(CONFIG_VMWARE_PVSCSI) += vmw_pvscsi.o
    +obj-$(CONFIG_HYPERV_STORAGE) += hv_storvsc.o

    obj-$(CONFIG_ARM) += arm/

    @@ -170,6 +171,8 @@ scsi_mod-$(CONFIG_SCSI_PROC_FS) += scsi_proc.o
    scsi_mod-y += scsi_trace.o
    scsi_mod-$(CONFIG_PM) += scsi_pm.o

    +hv_storvsc-y := storvsc_drv.o
    +
    scsi_tgt-y += scsi_tgt_lib.o scsi_tgt_if.o

    sd_mod-objs := sd.o
    diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
    new file mode 100644
    index 0000000..0245143
    --- /dev/null
    +++ b/drivers/scsi/storvsc_drv.c
    @@ -0,0 +1,1567 @@
    +/*
    + * Copyright (c) 2009, Microsoft Corporation.
    + *
    + * This program is free software; you can redistribute it and/or modify it
    + * under the terms and conditions of the GNU General Public License,
    + * version 2, as published by the Free Software Foundation.
    + *
    + * This program is distributed in the hope it will be useful, but WITHOUT
    + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
    + * more details.
    + *
    + * You should have received a copy of the GNU General Public License along with
    + * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
    + * Place - Suite 330, Boston, MA 02111-1307 USA.
    + *
    + * Authors:
    + * Haiyang Zhang <haiyangz@microsoft.com>
    + * Hank Janssen <hjanssen@microsoft.com>
    + * K. Y. Srinivasan <kys@microsoft.com>
    + */
    +
    +#include <linux/kernel.h>
    +#include <linux/wait.h>
    +#include <linux/sched.h>
    +#include <linux/completion.h>
    +#include <linux/string.h>
    +#include <linux/mm.h>
    +#include <linux/delay.h>
    +#include <linux/init.h>
    +#include <linux/slab.h>
    +#include <linux/module.h>
    +#include <linux/device.h>
    +#include <linux/hyperv.h>
    +#include <linux/mempool.h>
    +#include <scsi/scsi.h>
    +#include <scsi/scsi_cmnd.h>
    +#include <scsi/scsi_host.h>
    +#include <scsi/scsi_device.h>
    +#include <scsi/scsi_tcq.h>
    +#include <scsi/scsi_eh.h>
    +#include <scsi/scsi_devinfo.h>
    +#include <scsi/scsi_dbg.h>
    +
    +
    +#define STORVSC_MIN_BUF_NR 64
    +#define STORVSC_RING_BUFFER_SIZE (20*PAGE_SIZE)
    +static int storvsc_ringbuffer_size = STORVSC_RING_BUFFER_SIZE;
    +
    +module_param(storvsc_ringbuffer_size, int, S_IRUGO);
    +MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
    +
    +/* to alert the user that structure sizes may be mismatched even though the */
    +/* protocol versions match. */
    +
    +
    +#define REVISION_STRING(REVISION_) #REVISION_
    +#define FILL_VMSTOR_REVISION(RESULT_LVALUE_) \
    + do { \
    + char *revision_string \
    + = REVISION_STRING($Rev : 6 $) + 6; \
    + RESULT_LVALUE_ = 0; \
    + while (*revision_string >= '0' \
    + && *revision_string <= '9') { \
    + RESULT_LVALUE_ *= 10; \
    + RESULT_LVALUE_ += *revision_string - '0'; \
    + revision_string++; \
    + } \
    + } while (0)
    +
    +/* Major/minor macros. Minor version is in LSB, meaning that earlier flat */
    +/* version numbers will be interpreted as "0.x" (i.e., 1 becomes 0.1). */
    +#define VMSTOR_PROTOCOL_MAJOR(VERSION_) (((VERSION_) >> 8) & 0xff)
    +#define VMSTOR_PROTOCOL_MINOR(VERSION_) (((VERSION_)) & 0xff)
    +#define VMSTOR_PROTOCOL_VERSION(MAJOR_, MINOR_) ((((MAJOR_) & 0xff) << 8) | \
    + (((MINOR_) & 0xff)))
    +#define VMSTOR_INVALID_PROTOCOL_VERSION (-1)
    +
    +/* Version history: */
    +/* V1 Beta 0.1 */
    +/* V1 RC < 2008/1/31 1.0 */
    +/* V1 RC > 2008/1/31 2.0 */
    +#define VMSTOR_PROTOCOL_VERSION_CURRENT VMSTOR_PROTOCOL_VERSION(4, 2)
    +
    +
    +
    +
    +/* This will get replaced with the max transfer length that is possible on */
    +/* the host adapter. */
    +/* The max transfer length will be published when we offer a vmbus channel. */
    +#define MAX_TRANSFER_LENGTH 0x40000
    +#define DEFAULT_PACKET_SIZE (sizeof(struct vmdata_gpa_direct) + \
    + sizeof(struct vstor_packet) + \
    + sizesizeof(u64) * (MAX_TRANSFER_LENGTH / PAGE_SIZE)))
    +
    +
    +/* Packet structure describing virtual storage requests. */
    +enum vstor_packet_operation {
    + VSTOR_OPERATION_COMPLETE_IO = 1,
    + VSTOR_OPERATION_REMOVE_DEVICE = 2,
    + VSTOR_OPERATION_EXECUTE_SRB = 3,
    + VSTOR_OPERATION_RESET_LUN = 4,
    + VSTOR_OPERATION_RESET_ADAPTER = 5,
    + VSTOR_OPERATION_RESET_BUS = 6,
    + VSTOR_OPERATION_BEGIN_INITIALIZATION = 7,
    + VSTOR_OPERATION_END_INITIALIZATION = 8,
    + VSTOR_OPERATION_QUERY_PROTOCOL_VERSION = 9,
    + VSTOR_OPERATION_QUERY_PROPERTIES = 10,
    + VSTOR_OPERATION_ENUMERATE_BUS = 11,
    + VSTOR_OPERATION_MAXIMUM = 11
    +};
    +
    +/*
    + * Platform neutral description of a scsi request -
    + * this remains the same across the write regardless of 32/64 bit
    + * note: it's patterned off the SCSI_PASS_THROUGH structure
    + */
    +#define CDB16GENERIC_LENGTH 0x10
    +
    +#ifndef SENSE_BUFFER_SIZE
    +#define SENSE_BUFFER_SIZE 0x12
    +#endif
    +
    +#define MAX_DATA_BUF_LEN_WITH_PADDING 0x14
    +
    +struct vmscsi_request {
    + unsigned short length;
    + unsigned char srb_status;
    + unsigned char scsi_status;
    +
    + unsigned char port_number;
    + unsigned char path_id;
    + unsigned char target_id;
    + unsigned char lun;
    +
    + unsigned char cdb_length;
    + unsigned char sense_info_length;
    + unsigned char data_in;
    + unsigned char reserved;
    +
    + unsigned int data_transfer_length;
    +
    + union {
    + unsigned char cdb[CDB16GENERIC_LENGTH];
    + unsigned char sense_data[SENSE_BUFFER_SIZE];
    + unsigned char reserved_array[MAX_DATA_BUF_LEN_WITH_PADDING];
    + };
    +} __attribute((packed));
    +
    +
    +/*
    + * This structure is sent during the intialization phase to get the different
    + * properties of the channel.
    + */
    +struct vmstorage_channel_properties {
    + unsigned short protocol_version;
    + unsigned char path_id;
    + unsigned char target_id;
    +
    + /* Note: port number is only really known on the client side */
    + unsigned int port_number;
    + unsigned int flags;
    + unsigned int max_transfer_bytes;
    +
    + /* This id is unique for each channel and will correspond with */
    + /* vendor specific data in the inquirydata */
    + unsigned long long unique_id;
    +} __packed;
    +
    +/* This structure is sent during the storage protocol negotiations. */
    +struct vmstorage_protocol_version {
    + /* Major (MSW) and minor (LSW) version numbers. */
    + unsigned short major_minor;
    +
    + /*
    + * Revision number is auto-incremented whenever this file is changed
    + * (See FILL_VMSTOR_REVISION macro above). Mismatch does not
    + * definitely indicate incompatibility--but it does indicate mismatched
    + * builds.
    + */
    + unsigned short revision;
    +} __packed;
    +
    +/* Channel Property Flags */
    +#define STORAGE_CHANNEL_REMOVABLE_FLAG 0x1
    +#define STORAGE_CHANNEL_EMULATED_IDE_FLAG 0x2
    +
    +struct vstor_packet {
    + /* Requested operation type */
    + enum vstor_packet_operation operation;
    +
    + /* Flags - see below for values */
    + unsigned int flags;
    +
    + /* Status of the request returned from the server side. */
    + unsigned int status;
    +
    + /* Data payload area */
    + union {
    + /*
    + * Structure used to forward SCSI commands from the
    + * client to the server.
    + */
    + struct vmscsi_request vm_srb;
    +
    + /* Structure used to query channel properties. */
    + struct vmstorage_channel_properties storage_channel_properties;
    +
    + /* Used during version negotiations. */
    + struct vmstorage_protocol_version version;
    + };
    +} __packed;
    +
    +/* Packet flags */
    +/*
    + * This flag indicates that the server should send back a completion for this
    + * packet.
    + */
    +#define REQUEST_COMPLETION_FLAG 0x1
    +
    +/* This is the set of flags that the vsc can set in any packets it sends */
    +#define VSC_LEGAL_FLAGS (REQUEST_COMPLETION_FLAG)
    +
    +
    +/* Defines */
    +
    +#define STORVSC_MAX_IO_REQUESTS 128
    +
    +/*
    + * In Hyper-V, each port/path/target maps to 1 scsi host adapter. In
    + * reality, the path/target is not used (ie always set to 0) so our
    + * scsi host adapter essentially has 1 bus with 1 target that contains
    + * up to 256 luns.
    + */
    +#define STORVSC_MAX_LUNS_PER_TARGET 64
    +#define STORVSC_MAX_TARGETS 1
    +#define STORVSC_MAX_CHANNELS 1
    +#define STORVSC_MAX_CMD_LEN 16
    +
    +/* Matches Windows-end */
    +enum storvsc_request_type {
    + WRITE_TYPE,
    + READ_TYPE,
    + UNKNOWN_TYPE,
    +};
    +
    +
    +struct hv_storvsc_request {
    + struct hv_device *device;
    +
    + /* Synchronize the request/response if needed */
    + struct completion wait_event;
    +
    + unsigned char *sense_buffer;
    + void *context;
    + void (*on_io_completion)(struct hv_storvsc_request *request);
    + struct hv_multipage_buffer data_buffer;
    +
    + struct vstor_packet vstor_packet;
    +};
    +
    +
    +/* A storvsc device is a device object that contains a vmbus channel */
    +struct storvsc_device {
    + struct hv_device *device;
    +
    + bool destroy;
    + bool drain_notify;
    + atomic_t num_outstanding_req;
    + struct Scsi_Host *host;
    +
    + wait_queue_head_t waiting_to_drain;
    +
    + /*
    + * Each unique Port/Path/Target represents 1 channel ie scsi
    + * controller. In reality, the pathid, targetid is always 0
    + * and the port is set by us
    + */
    + unsigned int port_number;
    + unsigned char path_id;
    + unsigned char target_id;
    +
    + /* Used for vsc/vsp channel reset process */
    + struct hv_storvsc_request init_request;
    + struct hv_storvsc_request reset_request;
    +};
    +
    +struct hv_host_device {
    + struct hv_device *dev;
    + struct kmem_cache *request_pool;
    + mempool_t *request_mempool;
    + unsigned int port;
    + unsigned char path;
    + unsigned char target;
    +};
    +
    +struct storvsc_cmd_request {
    + struct list_head entry;
    + struct scsi_cmnd *cmd;
    +
    + unsigned int bounce_sgl_count;
    + struct scatterlist *bounce_sgl;
    +
    + struct hv_storvsc_request request;
    +};
    +
    +struct storvsc_scan_work {
    + struct work_struct work;
    + struct Scsi_Host *host;
    + uint lun;
    +};
    +
    +static void storvsc_bus_scan(struct work_struct *work)
    +{
    + struct storvsc_scan_work *wrk;
    + int id, order_id;
    +
    + wrk = container_of(work, struct storvsc_scan_work, work);
    + for (id = 0; id < wrk->host->max_id; ++id) {
    + if (wrk->host->reverse_ordering)
    + order_id = wrk->host->max_id - id - 1;
    + else
    + order_id = id;
    +
    + scsi_scan_target(&wrk->host->shost_gendev, 0,
    + order_id, SCAN_WILD_CARD, 1);
    + }
    + kfree(wrk);
    +}
    +
    +static void storvsc_remove_lun(struct work_struct *work)
    +{
    + struct storvsc_scan_work *wrk;
    + struct scsi_device *sdev;
    +
    + wrk = container_of(work, struct storvsc_scan_work, work);
    + if (!scsi_host_get(wrk->host))
    + goto done;
    +
    + sdev = scsi_device_lookup(wrk->host, 0, 0, wrk->lun);
    +
    + if (sdev) {
    + scsi_remove_device(sdev);
    + scsi_device_put(sdev);
    + }
    + scsi_host_put(wrk->host);
    +
    +done:
    + kfree(wrk);
    +}
    +
    +static inline struct storvsc_device *get_out_stor_device(
    + struct hv_device *device)
    +{
    + struct storvsc_device *stor_device;
    +
    + stor_device = hv_get_drvdata(device);
    +
    + if (stor_device && stor_device->destroy)
    + stor_device = NULL;
    +
    + return stor_device;
    +}
    +
    +
    +static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
    +{
    + dev->drain_notify = true;
    + wait_event(dev->waiting_to_drain,
    + atomic_read(&dev->num_outstanding_req) == 0);
    + dev->drain_notify = false;
    +}
    +
    +static inline struct storvsc_device *get_in_stor_device(
    + struct hv_device *device)
    +{
    + struct storvsc_device *stor_device;
    +
    + stor_device = hv_get_drvdata(device);
    +
    + if (!stor_device)
    + goto get_in_err;
    +
    + /*
    + * If the device is being destroyed; allow incoming
    + * traffic only to cleanup outstanding requests.
    + */
    +
    + if (stor_device->destroy &&
    + (atomic_read(&stor_device->num_outstanding_req) == 0))
    + stor_device = NULL;
    +
    +get_in_err:
    + return stor_device;
    +
    +}
    +
    +static int storvsc_channel_init(struct hv_device *device)
    +{
    + struct storvsc_device *stor_device;
    + struct hv_storvsc_request *request;
    + struct vstor_packet *vstor_packet;
    + int ret, t;
    +
    + stor_device = get_out_stor_device(device);
    + if (!stor_device)
    + return -ENODEV;
    +
    + request = &stor_device->init_request;
    + vstor_packet = &request->vstor_packet;
    +
    + /*
    + * Now, initiate the vsc/vsp initialization protocol on the open
    + * channel
    + */
    + memset(request, 0, sizeof(struct hv_storvsc_request));
    + init_completion(&request->wait_event);
    + vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
    + vstor_packet->flags = REQUEST_COMPLETION_FLAG;
    +
    + ret = vmbus_sendpacket(device->channel, vstor_packet,
    + sizeof(struct vstor_packet),
    + (unsigned long)request,
    + VM_PKT_DATA_INBAND,
    + VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
    + if (ret != 0)
    + goto cleanup;
    +
    + t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
    + if (t == 0) {
    + ret = -ETIMEDOUT;
    + goto cleanup;
    + }
    +
    + if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
    + vstor_packet->status != 0)
    + goto cleanup;
    +
    +
    + /* reuse the packet for version range supported */
    + memset(vstor_packet, 0, sizeof(struct vstor_packet));
    + vstor_packet->operation = VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
    + vstor_packet->flags = REQUEST_COMPLETION_FLAG;
    +
    + vstor_packet->version.major_minor = VMSTOR_PROTOCOL_VERSION_CURRENT;
    + FILL_VMSTOR_REVISION(vstor_packet->version.revision);
    +
    + ret = vmbus_sendpacket(device->channel, vstor_packet,
    + sizeof(struct vstor_packet),
    + (unsigned long)request,
    + VM_PKT_DATA_INBAND,
    + VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
    + if (ret != 0)
    + goto cleanup;
    +
    + t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
    + if (t == 0) {
    + ret = -ETIMEDOUT;
    + goto cleanup;
    + }
    +
    + if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
    + vstor_packet->status != 0)
    + goto cleanup;
    +
    +
    + memset(vstor_packet, 0, sizeof(struct vstor_packet));
    + vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
    + vstor_packet->flags = REQUEST_COMPLETION_FLAG;
    + vstor_packet->storage_channel_properties.port_number =
    + stor_device->port_number;
    +
    + ret = vmbus_sendpacket(device->channel, vstor_packet,
    + sizeof(struct vstor_packet),
    + (unsigned long)request,
    + VM_PKT_DATA_INBAND,
    + VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
    +
    + if (ret != 0)
    + goto cleanup;
    +
    + t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
    + if (t == 0) {
    + ret = -ETIMEDOUT;
    + goto cleanup;
    + }
    +
    + if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
    + vstor_packet->status != 0)
    + goto cleanup;
    +
    + stor_device->path_id = vstor_packet->storage_channel_properties.path_id;
    + stor_device->target_id
    + = vstor_packet->storage_channel_properties.target_id;
    +
    + memset(vstor_packet, 0, sizeof(struct vstor_packet));
    + vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
    + vstor_packet->flags = REQUEST_COMPLETION_FLAG;
    +
    + ret = vmbus_sendpacket(device->channel, vstor_packet,
    + sizeof(struct vstor_packet),
    + (unsigned long)request,
    + VM_PKT_DATA_INBAND,
    + VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
    +
    + if (ret != 0)
    + goto cleanup;
    +
    + t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
    + if (t == 0) {
    + ret = -ETIMEDOUT;
    + goto cleanup;
    + }
    +
    + if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
    + vstor_packet->status != 0)
    + goto cleanup;
    +
    +
    +cleanup:
    + return ret;
    +}
    +
    +static void storvsc_on_io_completion(struct hv_device *device,
    + struct vstor_packet *vstor_packet,
    + struct hv_storvsc_request *request)
    +{
    + struct storvsc_device *stor_device;
    + struct vstor_packet *stor_pkt;
    +
    + stor_device = hv_get_drvdata(device);
    + stor_pkt = &request->vstor_packet;
    +
    + /*
    + * The current SCSI handling on the host side does
    + * not correctly handle:
    + * INQUIRY command with page code parameter set to 0x80
    + * MODE_SENSE command with cmd[2] == 0x1c
    + *
    + * Setup srb and scsi status so this won't be fatal.
    + * We do this so we can distinguish truly fatal failues
    + * (srb status == 0x4) and off-line the device in that case.
    + */
    +
    + if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
    + (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
    + vstor_packet->vm_srb.scsi_status = 0;
    + vstor_packet->vm_srb.srb_status = 0x1;
    + }
    +
    +
    + /* Copy over the status...etc */
    + stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
    + stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
    + stor_pkt->vm_srb.sense_info_length =
    + vstor_packet->vm_srb.sense_info_length;
    +
    + if (vstor_packet->vm_srb.scsi_status != 0 ||
    + vstor_packet->vm_srb.srb_status != 1){
    + dev_warn(&device->device,
    + "cmd 0x%x scsi status 0x%x srb status 0x%x\n",
    + stor_pkt->vm_srb.cdb[0],
    + vstor_packet->vm_srb.scsi_status,
    + vstor_packet->vm_srb.srb_status);
    + }
    +
    + if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
    + /* CHECK_CONDITION */
    + if (vstor_packet->vm_srb.srb_status & 0x80) {
    + /* autosense data available */
    + dev_warn(&device->device,
    + "stor pkt %p autosense data valid - len %d\n",
    + request,
    + vstor_packet->vm_srb.sense_info_length);
    +
    + memcpy(request->sense_buffer,
    + vstor_packet->vm_srb.sense_data,
    + vstor_packet->vm_srb.sense_info_length);
    +
    + }
    + }
    +
    + stor_pkt->vm_srb.data_transfer_length =
    + vstor_packet->vm_srb.data_transfer_length;
    +
    + request->on_io_completion(request);
    +
    + if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
    + stor_device->drain_notify)
    + wake_up(&stor_device->waiting_to_drain);
    +
    +
    +}
    +
    +static void storvsc_on_receive(struct hv_device *device,
    + struct vstor_packet *vstor_packet,
    + struct hv_storvsc_request *request)
    +{
    + struct storvsc_scan_work *work;
    + struct storvsc_device *stor_device;
    +
    + switch (vstor_packet->operation) {
    + case VSTOR_OPERATION_COMPLETE_IO:
    + storvsc_on_io_completion(device, vstor_packet, request);
    + break;
    +
    + case VSTOR_OPERATION_REMOVE_DEVICE:
    + case VSTOR_OPERATION_ENUMERATE_BUS:
    + stor_device = get_in_stor_device(device);
    + work = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
    + if (!work)
    + return;
    +
    + INIT_WORK(&work->work, storvsc_bus_scan);
    + work->host = stor_device->host;
    + schedule_work(&work->work);
    + break;
    +
    + default:
    + break;
    + }
    +}
    +
    +static void storvsc_on_channel_callback(void *context)
    +{
    + struct hv_device *device = (struct hv_device *)context;
    + struct storvsc_device *stor_device;
    + u32 bytes_recvd;
    + u64 request_id;
    + unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
    + struct hv_storvsc_request *request;
    + int ret;
    +
    +
    + stor_device = get_in_stor_device(device);
    + if (!stor_device)
    + return;
    +
    + do {
    + ret = vmbus_recvpacket(device->channel, packet,
    + ALIGN(sizeof(struct vstor_packet), 8),
    + &bytes_recvd, &request_id);
    + if (ret == 0 && bytes_recvd > 0) {
    +
    + request = (struct hv_storvsc_request *)
    + (unsigned long)request_id;
    +
    + if ((request == &stor_device->init_request) ||
    + (request == &stor_device->reset_request)) {
    +
    + memcpy(&request->vstor_packet, packet,
    + sizeof(struct vstor_packet));
    + complete(&request->wait_event);
    + } else {
    + storvsc_on_receive(device,
    + (struct vstor_packet *)packet,
    + request);
    + }
    + } else {
    + break;
    + }
    + } while (1);
    +
    + return;
    +}
    +
    +static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size)
    +{
    + struct vmstorage_channel_properties props;
    + int ret;
    +
    + memset(&props, 0, sizeof(struct vmstorage_channel_properties));
    +
    + /* Open the channel */
    + ret = vmbus_open(device->channel,
    + ring_size,
    + ring_size,
    + (void *)&props,
    + sizeof(struct vmstorage_channel_properties),
    + storvsc_on_channel_callback, device);
    +
    + if (ret != 0)
    + return ret;
    +
    + ret = storvsc_channel_init(device);
    +
    + return ret;
    +}
    +
    +static int storvsc_dev_remove(struct hv_device *device)
    +{
    + struct storvsc_device *stor_device;
    + unsigned long flags;
    +
    + stor_device = hv_get_drvdata(device);
    +
    + spin_lock_irqsave(&device->channel->inbound_lock, flags);
    + stor_device->destroy = true;
    + spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
    +
    + /*
    + * At this point, all outbound traffic should be disable. We
    + * only allow inbound traffic (responses) to proceed so that
    + * outstanding requests can be completed.
    + */
    +
    + storvsc_wait_to_drain(stor_device);
    +
    + /*
    + * Since we have already drained, we don't need to busy wait
    + * as was done in final_release_stor_device()
    + * Note that we cannot set the ext pointer to NULL until
    + * we have drained - to drain the outgoing packets, we need to
    + * allow incoming packets.
    + */
    + spin_lock_irqsave(&device->channel->inbound_lock, flags);
    + hv_set_drvdata(device, NULL);
    + spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
    +
    + /* Close the channel */
    + vmbus_close(device->channel);
    +
    + kfree(stor_device);
    + return 0;
    +}
    +
    +static int storvsc_do_io(struct hv_device *device,
    + struct hv_storvsc_request *request)
    +{
    + struct storvsc_device *stor_device;
    + struct vstor_packet *vstor_packet;
    + int ret = 0;
    +
    + vstor_packet = &request->vstor_packet;
    + stor_device = get_out_stor_device(device);
    +
    + if (!stor_device)
    + return -ENODEV;
    +
    +
    + request->device = device;
    +
    +
    + vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
    +
    + vstor_packet->vm_srb.length = sizeof(struct vmscsi_request);
    +
    +
    + vstor_packet->vm_srb.sense_info_length = SENSE_BUFFER_SIZE;
    +
    +
    + vstor_packet->vm_srb.data_transfer_length =
    + request->data_buffer.len;
    +
    + vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
    +
    + if (request->data_buffer.len) {
    + ret = vmbus_sendpacket_multipagebuffer(device->channel,
    + &request->data_buffer,
    + vstor_packet,
    + sizeof(struct vstor_packet),
    + (unsigned long)request);
    + } else {
    + ret = vmbus_sendpacket(device->channel, vstor_packet,
    + sizeof(struct vstor_packet),
    + (unsigned long)request,
    + VM_PKT_DATA_INBAND,
    + VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
    + }
    +
    + if (ret != 0)
    + return ret;
    +
    + atomic_inc(&stor_device->num_outstanding_req);
    +
    + return ret;
    +}
    +
    +static void storvsc_get_ide_info(struct hv_device *dev, int *target, int *path)
    +{
    + *target =
    + dev->dev_instance.b[5] << 8 | dev->dev_instance.b[4];
    +
    + *path =
    + dev->dev_instance.b[3] << 24 |
    + dev->dev_instance.b[2] << 16 |
    + dev->dev_instance.b[1] << 8 | dev->dev_instance.b[0];
    +}
    +
    +
    +static int storvsc_device_alloc(struct scsi_device *sdevice)
    +{
    + /*
    + * This enables luns to be located sparsely. Otherwise, we may not
    + * discovered them.
    + */
    + sdevice->sdev_bflags |= BLIST_SPARSELUN | BLIST_LARGELUN;
    + return 0;
    +}
    +
    +static int storvsc_merge_bvec(struct request_queue *q,
    + struct bvec_merge_data *bmd, struct bio_vec *bvec)
    +{
    + /* checking done by caller. */
    + return bvec->bv_len;
    +}
    +
    +static int storvsc_device_configure(struct scsi_device *sdevice)
    +{
    + scsi_adjust_queue_depth(sdevice, MSG_SIMPLE_TAG,
    + STORVSC_MAX_IO_REQUESTS);
    +
    + blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
    +
    + blk_queue_merge_bvec(sdevice->request_queue, storvsc_merge_bvec);
    +
    + blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
    +
    + return 0;
    +}
    +
    +static void destroy_bounce_buffer(struct scatterlist *sgl,
    + unsigned int sg_count)
    +{
    + int i;
    + struct page *page_buf;
    +
    + for (i = 0; i < sg_count; i++) {
    + page_buf = sg_page((&sgl[i]));
    + if (page_buf != NULL)
    + __free_page(page_buf);
    + }
    +
    + kfree(sgl);
    +}
    +
    +static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
    +{
    + int i;
    +
    + /* No need to check */
    + if (sg_count < 2)
    + return -1;
    +
    + /* We have at least 2 sg entries */
    + for (i = 0; i < sg_count; i++) {
    + if (i == 0) {
    + /* make sure 1st one does not have hole */
    + if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
    + return i;
    + } else if (i == sg_count - 1) {
    + /* make sure last one does not have hole */
    + if (sgl[i].offset != 0)
    + return i;
    + } else {
    + /* make sure no hole in the middle */
    + if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
    + return i;
    + }
    + }
    + return -1;
    +}
    +
    +static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
    + unsigned int sg_count,
    + unsigned int len)
    +{
    + int i;
    + int num_pages;
    + struct scatterlist *bounce_sgl;
    + struct page *page_buf;
    +
    + num_pages = ALIGN(len, PAGE_SIZE) >> PAGE_SHIFT;
    +
    + bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
    + if (!bounce_sgl)
    + return NULL;
    +
    + for (i = 0; i < num_pages; i++) {
    + page_buf = alloc_page(GFP_ATOMIC);
    + if (!page_buf)
    + goto cleanup;
    + sg_set_page(&bounce_sgl[i], page_buf, 0, 0);
    + }
    +
    + return bounce_sgl;
    +
    +cleanup:
    + destroy_bounce_buffer(bounce_sgl, num_pages);
    + return NULL;
    +}
    +
    +
    +/* Assume the original sgl has enough room */
    +static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
    + struct scatterlist *bounce_sgl,
    + unsigned int orig_sgl_count)
    +{
    + int i;
    + int j = 0;
    + unsigned long src, dest;
    + unsigned int srclen, destlen, copylen;
    + unsigned int total_copied = 0;
    + unsigned long bounce_addr = 0;
    + unsigned long dest_addr = 0;
    + unsigned long flags;
    +
    + local_irq_save(flags);
    +
    + for (i = 0; i < orig_sgl_count; i++) {
    + dest_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
    + KM_IRQ0) + orig_sgl[i].offset;
    + dest = dest_addr;
    + destlen = orig_sgl[i].length;
    +
    + if (bounce_addr == 0)
    + bounce_addr =
    + (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])),
    + KM_IRQ0);
    +
    + while (destlen) {
    + src = bounce_addr + bounce_sgl[j].offset;
    + srclen = bounce_sgl[j].length - bounce_sgl[j].offset;
    +
    + copylen = min(srclen, destlen);
    + memcpy((void *)dest, (void *)src, copylen);
    +
    + total_copied += copylen;
    + bounce_sgl[j].offset += copylen;
    + destlen -= copylen;
    + dest += copylen;
    +
    + if (bounce_sgl[j].offset == bounce_sgl[j].length) {
    + /* full */
    + kunmap_atomic((void *)bounce_addr, KM_IRQ0);
    + j++;
    +
    + /* if we need to use another bounce buffer */
    + if (destlen || i != orig_sgl_count - 1)
    + bounce_addr =
    + (unsigned long)kmap_atomic(
    + sg_page((&bounce_sgl[j])), KM_IRQ0);
    + } else if (destlen == 0 && i == orig_sgl_count - 1) {
    + /* unmap the last bounce that is < PAGE_SIZE */
    + kunmap_atomic((void *)bounce_addr, KM_IRQ0);
    + }
    + }
    +
    + kunmap_atomic((void *)(dest_addr - orig_sgl[i].offset),
    + KM_IRQ0);
    + }
    +
    + local_irq_restore(flags);
    +
    + return total_copied;
    +}
    +
    +
    +/* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
    +static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
    + struct scatterlist *bounce_sgl,
    + unsigned int orig_sgl_count)
    +{
    + int i;
    + int j = 0;
    + unsigned long src, dest;
    + unsigned int srclen, destlen, copylen;
    + unsigned int total_copied = 0;
    + unsigned long bounce_addr = 0;
    + unsigned long src_addr = 0;
    + unsigned long flags;
    +
    + local_irq_save(flags);
    +
    + for (i = 0; i < orig_sgl_count; i++) {
    + src_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
    + KM_IRQ0) + orig_sgl[i].offset;
    + src = src_addr;
    + srclen = orig_sgl[i].length;
    +
    + if (bounce_addr == 0)
    + bounce_addr =
    + (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])),
    + KM_IRQ0);
    +
    + while (srclen) {
    + /* assume bounce offset always == 0 */
    + dest = bounce_addr + bounce_sgl[j].length;
    + destlen = PAGE_SIZE - bounce_sgl[j].length;
    +
    + copylen = min(srclen, destlen);
    + memcpy((void *)dest, (void *)src, copylen);
    +
    + total_copied += copylen;
    + bounce_sgl[j].length += copylen;
    + srclen -= copylen;
    + src += copylen;
    +
    + if (bounce_sgl[j].length == PAGE_SIZE) {
    + /* full..move to next entry */
    + kunmap_atomic((void *)bounce_addr, KM_IRQ0);
    + j++;
    +
    + /* if we need to use another bounce buffer */
    + if (srclen || i != orig_sgl_count - 1)
    + bounce_addr =
    + (unsigned long)kmap_atomic(
    + sg_page((&bounce_sgl[j])), KM_IRQ0);
    +
    + } else if (srclen == 0 && i == orig_sgl_count - 1) {
    + /* unmap the last bounce that is < PAGE_SIZE */
    + kunmap_atomic((void *)bounce_addr, KM_IRQ0);
    + }
    + }
    +
    + kunmap_atomic((void *)(src_addr - orig_sgl[i].offset), KM_IRQ0);
    + }
    +
    + local_irq_restore(flags);
    +
    + return total_copied;
    +}
    +
    +
    +static int storvsc_remove(struct hv_device *dev)
    +{
    + struct storvsc_device *stor_device = hv_get_drvdata(dev);
    + struct Scsi_Host *host = stor_device->host;
    + struct hv_host_device *host_dev = shost_priv(host);
    +
    + scsi_remove_host(host);
    +
    + scsi_host_put(host);
    +
    + storvsc_dev_remove(dev);
    + if (host_dev->request_pool) {
    + mempool_destroy(host_dev->request_mempool);
    + kmem_cache_destroy(host_dev->request_pool);
    + host_dev->request_pool = NULL;
    + host_dev->request_mempool = NULL;
    + }
    + return 0;
    +}
    +
    +
    +static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
    + sector_t capacity, int *info)
    +{
    + sector_t nsect = capacity;
    + sector_t cylinders = nsect;
    + int heads, sectors_pt;
    +
    + /*
    + * We are making up these values; let us keep it simple.
    + */
    + heads = 0xff;
    + sectors_pt = 0x3f; /* Sectors per track */
    + sector_div(cylinders, heads * sectors_pt);
    + if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
    + cylinders = 0xffff;
    +
    + info[0] = heads;
    + info[1] = sectors_pt;
    + info[2] = (int)cylinders;
    +
    + return 0;
    +}
    +
    +static int storvsc_host_reset(struct hv_device *device)
    +{
    + struct storvsc_device *stor_device;
    + struct hv_storvsc_request *request;
    + struct vstor_packet *vstor_packet;
    + int ret, t;
    +
    +
    + stor_device = get_out_stor_device(device);
    + if (!stor_device)
    + return FAILED;
    +
    + request = &stor_device->reset_request;
    + vstor_packet = &request->vstor_packet;
    +
    + init_completion(&request->wait_event);
    +
    + vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
    + vstor_packet->flags = REQUEST_COMPLETION_FLAG;
    + vstor_packet->vm_srb.path_id = stor_device->path_id;
    +
    + ret = vmbus_sendpacket(device->channel, vstor_packet,
    + sizeof(struct vstor_packet),
    + (unsigned long)&stor_device->reset_request,
    + VM_PKT_DATA_INBAND,
    + VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
    + if (ret != 0)
    + return FAILED;
    +
    + t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
    + if (t == 0)
    + return TIMEOUT_ERROR;
    +
    +
    + /*
    + * At this point, all outstanding requests in the adapter
    + * should have been flushed out and return to us
    + */
    +
    + return SUCCESS;
    +}
    +
    +
    +/*
    + * storvsc_host_reset_handler - Reset the scsi HBA
    + */
    +static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
    +{
    + struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
    + struct hv_device *dev = host_dev->dev;
    +
    + return storvsc_host_reset(dev);
    +}
    +
    +
    +/*
    + * storvsc_command_completion - Command completion processing
    + */
    +static void storvsc_command_completion(struct hv_storvsc_request *request)
    +{
    + struct storvsc_cmd_request *cmd_request =
    + (struct storvsc_cmd_request *)request->context;
    + struct scsi_cmnd *scmnd = cmd_request->cmd;
    + struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
    + void (*scsi_done_fn)(struct scsi_cmnd *);
    + struct scsi_sense_hdr sense_hdr;
    + struct vmscsi_request *vm_srb;
    + struct storvsc_scan_work *wrk;
    +
    + vm_srb = &request->vstor_packet.vm_srb;
    + if (cmd_request->bounce_sgl_count) {
    + if (vm_srb->data_in == READ_TYPE) {
    + copy_from_bounce_buffer(scsi_sglist(scmnd),
    + cmd_request->bounce_sgl,
    + scsi_sg_count(scmnd));
    + destroy_bounce_buffer(cmd_request->bounce_sgl,
    + cmd_request->bounce_sgl_count);
    + }
    + }
    +
    + /*
    + * If there is an error; offline the device since all
    + * error recovery strategies would have already been
    + * deployed on the host side.
    + */
    + if (vm_srb->srb_status == 0x4)
    + scmnd->result = DID_TARGET_FAILURE << 16;
    + else
    + scmnd->result = vm_srb->scsi_status;
    +
    + /*
    + * If the LUN is invalid; remove the device.
    + */
    + if (vm_srb->srb_status == 0x20) {
    + struct storvsc_device *stor_dev;
    + struct hv_device *dev = host_dev->dev;
    + struct Scsi_Host *host;
    +
    + stor_dev = get_in_stor_device(dev);
    + host = stor_dev->host;
    +
    + wrk = kmalloc(sizeof(struct storvsc_scan_work),
    + GFP_ATOMIC);
    + if (!wrk) {
    + scmnd->result = DID_TARGET_FAILURE << 16;
    + } else {
    + wrk->host = host;
    + wrk->lun = vm_srb->lun;
    + INIT_WORK(&wrk->work, storvsc_remove_lun);
    + schedule_work(&wrk->work);
    + }
    + }
    +
    + if (scmnd->result) {
    + if (scsi_normalize_sense(scmnd->sense_buffer,
    + SCSI_SENSE_BUFFERSIZE, &sense_hdr))
    + scsi_print_sense_hdr("storvsc", &sense_hdr);
    + }
    +
    + scsi_set_resid(scmnd,
    + request->data_buffer.len -
    + vm_srb->data_transfer_length);
    +
    + scsi_done_fn = scmnd->scsi_done;
    +
    + scmnd->host_scribble = NULL;
    + scmnd->scsi_done = NULL;
    +
    + scsi_done_fn(scmnd);
    +
    + mempool_free(cmd_request, host_dev->request_mempool);
    +}
    +
    +static bool storvsc_check_scsi_cmd(struct scsi_cmnd *scmnd)
    +{
    + bool allowed = true;
    + u8 scsi_op = scmnd->cmnd[0];
    +
    + switch (scsi_op) {
    + /* smartd sends this command, which will offline the device */
    + case SET_WINDOW:
    + scmnd->result = ILLEGAL_REQUEST << 16;
    + allowed = false;
    + break;
    + default:
    + break;
    + }
    + return allowed;
    +}
    +
    +/*
    + * storvsc_queuecommand - Initiate command processing
    + */
    +static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
    +{
    + int ret;
    + struct hv_host_device *host_dev = shost_priv(host);
    + struct hv_device *dev = host_dev->dev;
    + struct hv_storvsc_request *request;
    + struct storvsc_cmd_request *cmd_request;
    + unsigned int request_size = 0;
    + int i;
    + struct scatterlist *sgl;
    + unsigned int sg_count = 0;
    + struct vmscsi_request *vm_srb;
    +
    + if (storvsc_check_scsi_cmd(scmnd) == false) {
    + scmnd->scsi_done(scmnd);
    + return 0;
    + }
    +
    + /* If retrying, no need to prep the cmd */
    + if (scmnd->host_scribble) {
    +
    + cmd_request =
    + (struct storvsc_cmd_request *)scmnd->host_scribble;
    +
    + goto retry_request;
    + }
    +
    + request_size = sizeof(struct storvsc_cmd_request);
    +
    + cmd_request = mempool_alloc(host_dev->request_mempool,
    + GFP_ATOMIC);
    + if (!cmd_request)
    + return SCSI_MLQUEUE_DEVICE_BUSY;
    +
    + memset(cmd_request, 0, sizeof(struct storvsc_cmd_request));
    +
    + /* Setup the cmd request */
    + cmd_request->bounce_sgl_count = 0;
    + cmd_request->bounce_sgl = NULL;
    + cmd_request->cmd = scmnd;
    +
    + scmnd->host_scribble = (unsigned char *)cmd_request;
    +
    + request = &cmd_request->request;
    + vm_srb = &request->vstor_packet.vm_srb;
    +
    +
    + /* Build the SRB */
    + switch (scmnd->sc_data_direction) {
    + case DMA_TO_DEVICE:
    + vm_srb->data_in = WRITE_TYPE;
    + break;
    + case DMA_FROM_DEVICE:
    + vm_srb->data_in = READ_TYPE;
    + break;
    + default:
    + vm_srb->data_in = UNKNOWN_TYPE;
    + break;
    + }
    +
    + request->on_io_completion = storvsc_command_completion;
    + request->context = cmd_request;/* scmnd; */
    +
    + vm_srb->port_number = host_dev->port;
    + vm_srb->path_id = scmnd->device->channel;
    + vm_srb->target_id = scmnd->device->id;
    + vm_srb->lun = scmnd->device->lun;
    +
    + vm_srb->cdb_length = scmnd->cmd_len;
    +
    + memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
    +
    + request->sense_buffer = scmnd->sense_buffer;
    +
    +
    + request->data_buffer.len = scsi_bufflen(scmnd);
    + if (scsi_sg_count(scmnd)) {
    + sgl = (struct scatterlist *)scsi_sglist(scmnd);
    + sg_count = scsi_sg_count(scmnd);
    +
    + /* check if we need to bounce the sgl */
    + if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
    + cmd_request->bounce_sgl =
    + create_bounce_buffer(sgl, scsi_sg_count(scmnd),
    + scsi_bufflen(scmnd));
    + if (!cmd_request->bounce_sgl) {
    + scmnd->host_scribble = NULL;
    + mempool_free(cmd_request,
    + host_dev->request_mempool);
    +
    + return SCSI_MLQUEUE_HOST_BUSY;
    + }
    +
    + cmd_request->bounce_sgl_count =
    + ALIGN(scsi_bufflen(scmnd), PAGE_SIZE) >>
    + PAGE_SHIFT;
    +
    + if (vm_srb->data_in == WRITE_TYPE)
    + copy_to_bounce_buffer(sgl,
    + cmd_request->bounce_sgl,
    + scsi_sg_count(scmnd));
    +
    + sgl = cmd_request->bounce_sgl;
    + sg_count = cmd_request->bounce_sgl_count;
    + }
    +
    + request->data_buffer.offset = sgl[0].offset;
    +
    + for (i = 0; i < sg_count; i++)
    + request->data_buffer.pfn_array[i] =
    + page_to_pfn(sg_page((&sgl[i])));
    +
    + } else if (scsi_sglist(scmnd)) {
    + request->data_buffer.offset =
    + virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
    + request->data_buffer.pfn_array[0] =
    + virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
    + }
    +
    +retry_request:
    + /* Invokes the vsc to start an IO */
    + ret = storvsc_do_io(dev, &cmd_request->request);
    +
    + if (ret == -EAGAIN) {
    + /* no more space */
    +
    + if (cmd_request->bounce_sgl_count)
    + destroy_bounce_buffer(cmd_request->bounce_sgl,
    + cmd_request->bounce_sgl_count);
    +
    + mempool_free(cmd_request, host_dev->request_mempool);
    +
    + scmnd->host_scribble = NULL;
    +
    + ret = SCSI_MLQUEUE_DEVICE_BUSY;
    + }
    +
    + return ret;
    +}
    +
    +/* Scsi driver */
    +static struct scsi_host_template scsi_driver = {
    + .module = THIS_MODULE,
    + .name = "storvsc_host_t",
    + .bios_param = storvsc_get_chs,
    + .queuecommand = storvsc_queuecommand,
    + .eh_host_reset_handler = storvsc_host_reset_handler,
    + .slave_alloc = storvsc_device_alloc,
    + .slave_configure = storvsc_device_configure,
    + .cmd_per_lun = 1,
    + /* 64 max_queue * 1 target */
    + .can_queue = STORVSC_MAX_IO_REQUESTS*STORVSC_MAX_TARGETS,
    + .this_id = -1,
    + /* no use setting to 0 since ll_blk_rw reset it to 1 */
    + /* currently 32 */
    + .sg_tablesize = MAX_MULTIPAGE_BUFFER_COUNT,
    + /*
    + * ENABLE_CLUSTERING allows mutiple physically contig bio_vecs to merge
    + * into 1 sg element. If set, we must limit the max_segment_size to
    + * PAGE_SIZE, otherwise we may get 1 sg element that represents
    + * multiple
    + */
    + /* physically contig pfns (ie sg[x].length > PAGE_SIZE). */
    + .use_clustering = ENABLE_CLUSTERING,
    + /* Make sure we dont get a sg segment crosses a page boundary */
    + .dma_boundary = PAGE_SIZE-1,
    +};
    +
    +enum {
    + SCSI_GUID,
    + IDE_GUID,
    +};
    +
    +static const struct hv_vmbus_device_id id_table[] = {
    + /* SCSI guid */
    + { VMBUS_DEVICE(0xd9, 0x63, 0x61, 0xba, 0xa1, 0x04, 0x29, 0x4d,
    + 0xb6, 0x05, 0x72, 0xe2, 0xff, 0xb1, 0xdc, 0x7f)
    + .driver_data = SCSI_GUID },
    + /* IDE guid */
    + { VMBUS_DEVICE(0x32, 0x26, 0x41, 0x32, 0xcb, 0x86, 0xa2, 0x44,
    + 0x9b, 0x5c, 0x50, 0xd1, 0x41, 0x73, 0x54, 0xf5)
    + .driver_data = IDE_GUID },
    + { },
    +};
    +
    +MODULE_DEVICE_TABLE(vmbus, id_table);
    +
    +
    +/*
    + * storvsc_probe - Add a new device for this driver
    + */
    +
    +static int storvsc_probe(struct hv_device *device,
    + const struct hv_vmbus_device_id *dev_id)
    +{
    + int ret;
    + int number = STORVSC_MIN_BUF_NR;
    + struct Scsi_Host *host;
    + struct hv_host_device *host_dev;
    + bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
    + int path = 0;
    + int target = 0;
    + struct storvsc_device *stor_device;
    +
    + host = scsi_host_alloc(&scsi_driver,
    + sizeof(struct hv_host_device));
    + if (!host)
    + return -ENOMEM;
    +
    + host_dev = shost_priv(host);
    + memset(host_dev, 0, sizeof(struct hv_host_device));
    +
    + host_dev->port = host->host_no;
    + host_dev->dev = device;
    +
    + host_dev->request_pool =
    + kmem_cache_create(dev_name(&device->device),
    + sizeof(struct storvsc_cmd_request), 0,
    + SLAB_HWCACHE_ALIGN, NULL);
    +
    + if (!host_dev->request_pool) {
    + scsi_host_put(host);
    + return -ENOMEM;
    + }
    +
    + host_dev->request_mempool = mempool_create(number, mempool_alloc_slab,
    + mempool_free_slab,
    + host_dev->request_pool);
    +
    + if (!host_dev->request_mempool) {
    + ret = -ENOMEM;
    + goto err_out0;
    + }
    +
    + stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
    + if (!stor_device) {
    + ret = -ENOMEM;
    + goto err_out1;
    + }
    +
    + stor_device->destroy = false;
    + init_waitqueue_head(&stor_device->waiting_to_drain);
    + stor_device->device = device;
    + stor_device->host = host;
    + hv_set_drvdata(device, stor_device);
    +
    + stor_device->port_number = host->host_no;
    + ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size);
    + if (ret)
    + goto err_out2;
    +
    + if (dev_is_ide)
    + storvsc_get_ide_info(device, &target, &path);
    +
    + host_dev->path = stor_device->path_id;
    + host_dev->target = stor_device->target_id;
    +
    + /* max # of devices per target */
    + host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
    + /* max # of targets per channel */
    + host->max_id = STORVSC_MAX_TARGETS;
    + /* max # of channels */
    + host->max_channel = STORVSC_MAX_CHANNELS - 1;
    + /* max cmd length */
    + host->max_cmd_len = STORVSC_MAX_CMD_LEN;
    +
    + /* Register the HBA and start the scsi bus scan */
    + ret = scsi_add_host(host, &device->device);
    + if (ret != 0)
    + goto err_out3;
    +
    + if (!dev_is_ide) {
    + scsi_scan_host(host);
    + return 0;
    + }
    + ret = scsi_add_device(host, 0, target, 0);
    + if (ret) {
    + scsi_remove_host(host);
    + goto err_out3;
    + }
    + return 0;
    +
    +err_out3:
    + /*
    + * Once we have connected with the host, we would need to
    + * to invoke storvsc_dev_remove() to rollback this state and
    + * this call also frees up the stor_device; hence the jump around
    + * err_out2 label.
    + */
    + storvsc_dev_remove(device);
    + goto err_out1;
    +
    +err_out2:
    + kfree(stor_device);
    +
    +err_out1:
    + mempool_destroy(host_dev->request_mempool);
    +
    +err_out0:
    + kmem_cache_destroy(host_dev->request_pool);
    + scsi_host_put(host);
    + return ret;
    +}
    +
    +/* The one and only one */
    +
    +static struct hv_driver storvsc_drv = {
    + .name = KBUILD_MODNAME,
    + .id_table = id_table,
    + .probe = storvsc_probe,
    + .remove = storvsc_remove,
    +};
    +
    +static int __init storvsc_drv_init(void)
    +{
    + u32 max_outstanding_req_per_channel;
    +
    + /*
    + * 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) by the max request size (which is
    + * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
    + */
    + max_outstanding_req_per_channel =
    + ((storvsc_ringbuffer_size - PAGE_SIZE) /
    + ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
    + sizeof(struct vstor_packet) + sizeof(u64),
    + sizeof(u64)));
    +
    + if (max_outstanding_req_per_channel <
    + STORVSC_MAX_IO_REQUESTS)
    + return -EINVAL;
    +
    + return vmbus_driver_register(&storvsc_drv);
    +}
    +
    +static void __exit storvsc_drv_exit(void)
    +{
    + vmbus_driver_unregister(&storvsc_drv);
    +}
    +
    +MODULE_LICENSE("GPL");
    +MODULE_VERSION(HV_DRV_VERSION);
    +MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
    +module_init(storvsc_drv_init);
    +module_exit(storvsc_drv_exit);
    --
    1.7.4.1


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