Added missing tegra files.HEADmaster

1 files changed, 877 insertions, 0 deletions

diff --git a/drivers/staging/hv/channel.c b/drivers/staging/hv/channel.c
new file mode 100644
index 00000000000..455f47a891f
--- /dev/null
+++ b/drivers/staging/hv/channel.c
@@ -0,0 +1,877 @@
+/*
+ * 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>
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+
+#include "hyperv.h"
+#include "hyperv_vmbus.h"
+
+#define NUM_PAGES_SPANNED(addr, len) \
+((PAGE_ALIGN(addr + len) >> PAGE_SHIFT) - (addr >> PAGE_SHIFT))
+
+/* Internal routines */
+static int create_gpadl_header(
+        void *kbuffer,  /* must be phys and virt contiguous */
+        u32 size,       /* page-size multiple */
+        struct vmbus_channel_msginfo **msginfo,
+        u32 *messagecount);
+static void vmbus_setevent(struct vmbus_channel *channel);
+
+/*
+ * vmbus_setevent- Trigger an event notification on the specified
+ * channel.
+ */
+static void vmbus_setevent(struct vmbus_channel *channel)
+{
+        struct hv_monitor_page *monitorpage;
+
+        if (channel->offermsg.monitor_allocated) {
+                /* Each u32 represents 32 channels */
+                sync_set_bit(channel->offermsg.child_relid & 31,
+                        (unsigned long *) vmbus_connection.send_int_page +
+                        (channel->offermsg.child_relid >> 5));
+
+                monitorpage = vmbus_connection.monitor_pages;
+                monitorpage++; /* Get the child to parent monitor page */
+
+                sync_set_bit(channel->monitor_bit,
+                        (unsigned long *)&monitorpage->trigger_group
+                                        [channel->monitor_grp].pending);
+
+        } else {
+                vmbus_set_event(channel->offermsg.child_relid);
+        }
+}
+
+/*
+ * vmbus_get_debug_info -Retrieve various channel debug info
+ */
+void vmbus_get_debug_info(struct vmbus_channel *channel,
+                              struct vmbus_channel_debug_info *debuginfo)
+{
+        struct hv_monitor_page *monitorpage;
+        u8 monitor_group = (u8)channel->offermsg.monitorid / 32;
+        u8 monitor_offset = (u8)channel->offermsg.monitorid % 32;
+        /* u32 monitorBit       = 1 << monitorOffset; */
+
+        debuginfo->relid = channel->offermsg.child_relid;
+        debuginfo->state = channel->state;
+        memcpy(&debuginfo->interfacetype,
+               &channel->offermsg.offer.if_type, sizeof(struct hv_guid));
+        memcpy(&debuginfo->interface_instance,
+               &channel->offermsg.offer.if_instance,
+               sizeof(struct hv_guid));
+
+        monitorpage = (struct hv_monitor_page *)vmbus_connection.monitor_pages;
+
+        debuginfo->monitorid = channel->offermsg.monitorid;
+
+        debuginfo->servermonitor_pending =
+                        monitorpage->trigger_group[monitor_group].pending;
+        debuginfo->servermonitor_latency =
+                        monitorpage->latency[monitor_group][monitor_offset];
+        debuginfo->servermonitor_connectionid =
+                        monitorpage->parameter[monitor_group]
+                                        [monitor_offset].connectionid.u.id;
+
+        monitorpage++;
+
+        debuginfo->clientmonitor_pending =
+                        monitorpage->trigger_group[monitor_group].pending;
+        debuginfo->clientmonitor_latency =
+                        monitorpage->latency[monitor_group][monitor_offset];
+        debuginfo->clientmonitor_connectionid =
+                        monitorpage->parameter[monitor_group]
+                                        [monitor_offset].connectionid.u.id;
+
+        hv_ringbuffer_get_debuginfo(&channel->inbound, &debuginfo->inbound);
+        hv_ringbuffer_get_debuginfo(&channel->outbound, &debuginfo->outbound);
+}
+
+/*
+ * vmbus_open - Open the specified channel.
+ */
+int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
+                     u32 recv_ringbuffer_size, void *userdata, u32 userdatalen,
+                     void (*onchannelcallback)(void *context), void *context)
+{
+        struct vmbus_channel_open_channel *openMsg;
+        struct vmbus_channel_msginfo *openInfo = NULL;
+        void *in, *out;
+        unsigned long flags;
+        int ret, t, err = 0;
+
+        newchannel->onchannel_callback = onchannelcallback;
+        newchannel->channel_callback_context = context;
+
+        /* Allocate the ring buffer */
+        out = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
+                get_order(send_ringbuffer_size + recv_ringbuffer_size));
+
+        if (!out)
+                return -ENOMEM;
+
+
+        in = (void *)((unsigned long)out + send_ringbuffer_size);
+
+        newchannel->ringbuffer_pages = out;
+        newchannel->ringbuffer_pagecount = (send_ringbuffer_size +
+                                           recv_ringbuffer_size) >> PAGE_SHIFT;
+
+        ret = hv_ringbuffer_init(
+                &newchannel->outbound, out, send_ringbuffer_size);
+
+        if (ret != 0) {
+                err = ret;
+                goto errorout;
+        }
+
+        ret = hv_ringbuffer_init(
+                &newchannel->inbound, in, recv_ringbuffer_size);
+        if (ret != 0) {
+                err = ret;
+                goto errorout;
+        }
+
+
+        /* Establish the gpadl for the ring buffer */
+        newchannel->ringbuffer_gpadlhandle = 0;
+
+        ret = vmbus_establish_gpadl(newchannel,
+                                         newchannel->outbound.ring_buffer,
+                                         send_ringbuffer_size +
+                                         recv_ringbuffer_size,
+                                         &newchannel->ringbuffer_gpadlhandle);
+
+        if (ret != 0) {
+                err = ret;
+                goto errorout;
+        }
+
+        /* Create and init the channel open message */
+        openInfo = kmalloc(sizeof(*openInfo) +
+                           sizeof(struct vmbus_channel_open_channel),
+                           GFP_KERNEL);
+        if (!openInfo) {
+                err = -ENOMEM;
+                goto errorout;
+        }
+
+        init_completion(&openInfo->waitevent);
+
+        openMsg = (struct vmbus_channel_open_channel *)openInfo->msg;
+        openMsg->header.msgtype = CHANNELMSG_OPENCHANNEL;
+        openMsg->openid = newchannel->offermsg.child_relid;
+        openMsg->child_relid = newchannel->offermsg.child_relid;
+        openMsg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
+        openMsg->downstream_ringbuffer_pageoffset = send_ringbuffer_size >>
+                                                  PAGE_SHIFT;
+        openMsg->server_contextarea_gpadlhandle = 0;
+
+        if (userdatalen > MAX_USER_DEFINED_BYTES) {
+                err = -EINVAL;
+                goto errorout;
+        }
+
+        if (userdatalen)
+                memcpy(openMsg->userdata, userdata, userdatalen);
+
+        spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
+        list_add_tail(&openInfo->msglistentry,
+                      &vmbus_connection.chn_msg_list);
+        spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
+
+        ret = vmbus_post_msg(openMsg,
+                               sizeof(struct vmbus_channel_open_channel));
+
+        if (ret != 0)
+                goto cleanup;
+
+        t = wait_for_completion_timeout(&openInfo->waitevent, 5*HZ);
+        if (t == 0) {
+                err = -ETIMEDOUT;
+                goto errorout;
+        }
+
+
+        if (openInfo->response.open_result.status)
+                err = openInfo->response.open_result.status;
+
+cleanup:
+        spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
+        list_del(&openInfo->msglistentry);
+        spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
+
+        kfree(openInfo);
+        return err;
+
+errorout:
+        hv_ringbuffer_cleanup(&newchannel->outbound);
+        hv_ringbuffer_cleanup(&newchannel->inbound);
+        free_pages((unsigned long)out,
+                get_order(send_ringbuffer_size + recv_ringbuffer_size));
+        kfree(openInfo);
+        return err;
+}
+EXPORT_SYMBOL_GPL(vmbus_open);
+
+/*
+ * dump_gpadl_body - Dump the gpadl body message to the console for
+ * debugging purposes.
+ */
+static void dump_gpadl_body(struct vmbus_channel_gpadl_body *gpadl, u32 len)
+{
+        int i;
+        int pfncount;
+
+        pfncount = (len - sizeof(struct vmbus_channel_gpadl_body)) /
+                   sizeof(u64);
+
+        DPRINT_DBG(VMBUS, "gpadl body - len %d pfn count %d", len, pfncount);
+
+        for (i = 0; i < pfncount; i++)
+                DPRINT_DBG(VMBUS, "gpadl body  - %d) pfn %llu",
+                           i, gpadl->pfn[i]);
+}
+
+/*
+ * dump_gpadl_header - Dump the gpadl header message to the console for
+ * debugging purposes.
+ */
+static void dump_gpadl_header(struct vmbus_channel_gpadl_header *gpadl)
+{
+        int i, j;
+        int pagecount;
+
+        DPRINT_DBG(VMBUS,
+                   "gpadl header - relid %d, range count %d, range buflen %d",
+                   gpadl->child_relid, gpadl->rangecount, gpadl->range_buflen);
+        for (i = 0; i < gpadl->rangecount; i++) {
+                pagecount = gpadl->range[i].byte_count >> PAGE_SHIFT;
+                pagecount = (pagecount > 26) ? 26 : pagecount;
+
+                DPRINT_DBG(VMBUS, "gpadl range %d - len %d offset %d "
+                           "page count %d", i, gpadl->range[i].byte_count,
+                           gpadl->range[i].byte_offset, pagecount);
+
+                for (j = 0; j < pagecount; j++)
+                        DPRINT_DBG(VMBUS, "%d) pfn %llu", j,
+                                   gpadl->range[i].pfn_array[j]);
+        }
+}
+
+/*
+ * create_gpadl_header - Creates a gpadl for the specified buffer
+ */
+static int create_gpadl_header(void *kbuffer, u32 size,
+                                         struct vmbus_channel_msginfo **msginfo,
+                                         u32 *messagecount)
+{
+        int i;
+        int pagecount;
+        unsigned long long pfn;
+        struct vmbus_channel_gpadl_header *gpadl_header;
+        struct vmbus_channel_gpadl_body *gpadl_body;
+        struct vmbus_channel_msginfo *msgheader;
+        struct vmbus_channel_msginfo *msgbody = NULL;
+        u32 msgsize;
+
+        int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
+
+        pagecount = size >> PAGE_SHIFT;
+        pfn = virt_to_phys(kbuffer) >> PAGE_SHIFT;
+
+        /* do we need a gpadl body msg */
+        pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
+                  sizeof(struct vmbus_channel_gpadl_header) -
+                  sizeof(struct gpa_range);
+        pfncount = pfnsize / sizeof(u64);
+
+        if (pagecount > pfncount) {
+                /* we need a gpadl body */
+                /* fill in the header */
+                msgsize = sizeof(struct vmbus_channel_msginfo) +
+                          sizeof(struct vmbus_channel_gpadl_header) +
+                          sizeof(struct gpa_range) + pfncount * sizeof(u64);
+                msgheader =  kzalloc(msgsize, GFP_KERNEL);
+                if (!msgheader)
+                        goto nomem;
+
+                INIT_LIST_HEAD(&msgheader->submsglist);
+                msgheader->msgsize = msgsize;
+
+                gpadl_header = (struct vmbus_channel_gpadl_header *)
+                        msgheader->msg;
+                gpadl_header->rangecount = 1;
+                gpadl_header->range_buflen = sizeof(struct gpa_range) +
+                                         pagecount * sizeof(u64);
+                gpadl_header->range[0].byte_offset = 0;
+                gpadl_header->range[0].byte_count = size;
+                for (i = 0; i < pfncount; i++)
+                        gpadl_header->range[0].pfn_array[i] = pfn+i;
+                *msginfo = msgheader;
+                *messagecount = 1;
+
+                pfnsum = pfncount;
+                pfnleft = pagecount - pfncount;
+
+                /* how many pfns can we fit */
+                pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
+                          sizeof(struct vmbus_channel_gpadl_body);
+                pfncount = pfnsize / sizeof(u64);
+
+                /* fill in the body */
+                while (pfnleft) {
+                        if (pfnleft > pfncount)
+                                pfncurr = pfncount;
+                        else
+                                pfncurr = pfnleft;
+
+                        msgsize = sizeof(struct vmbus_channel_msginfo) +
+                                  sizeof(struct vmbus_channel_gpadl_body) +
+                                  pfncurr * sizeof(u64);
+                        msgbody = kzalloc(msgsize, GFP_KERNEL);
+
+                        if (!msgbody) {
+                                struct vmbus_channel_msginfo *pos = NULL;
+                                struct vmbus_channel_msginfo *tmp = NULL;
+                                /*
+                                 * Free up all the allocated messages.
+                                 */
+                                list_for_each_entry_safe(pos, tmp,
+                                        &msgheader->submsglist,
+                                        msglistentry) {
+
+                                        list_del(&pos->msglistentry);
+                                        kfree(pos);
+                                }
+
+                                goto nomem;
+                        }
+
+                        msgbody->msgsize = msgsize;
+                        (*messagecount)++;
+                        gpadl_body =
+                                (struct vmbus_channel_gpadl_body *)msgbody->msg;
+
+                        /*
+                         * Gpadl is u32 and we are using a pointer which could
+                         * be 64-bit
+                         * This is governed by the guest/host protocol and
+                         * so the hypervisor gurantees that this is ok.
+                         */
+                        for (i = 0; i < pfncurr; i++)
+                                gpadl_body->pfn[i] = pfn + pfnsum + i;
+
+                        /* add to msg header */
+                        list_add_tail(&msgbody->msglistentry,
+                                      &msgheader->submsglist);
+                        pfnsum += pfncurr;
+                        pfnleft -= pfncurr;
+                }
+        } else {
+                /* everything fits in a header */
+                msgsize = sizeof(struct vmbus_channel_msginfo) +
+                          sizeof(struct vmbus_channel_gpadl_header) +
+                          sizeof(struct gpa_range) + pagecount * sizeof(u64);
+                msgheader = kzalloc(msgsize, GFP_KERNEL);
+                if (msgheader == NULL)
+                        goto nomem;
+                msgheader->msgsize = msgsize;
+
+                gpadl_header = (struct vmbus_channel_gpadl_header *)
+                        msgheader->msg;
+                gpadl_header->rangecount = 1;
+                gpadl_header->range_buflen = sizeof(struct gpa_range) +
+                                         pagecount * sizeof(u64);
+                gpadl_header->range[0].byte_offset = 0;
+                gpadl_header->range[0].byte_count = size;
+                for (i = 0; i < pagecount; i++)
+                        gpadl_header->range[0].pfn_array[i] = pfn+i;
+
+                *msginfo = msgheader;
+                *messagecount = 1;
+        }
+
+        return 0;
+nomem:
+        kfree(msgheader);
+        kfree(msgbody);
+        return -ENOMEM;
+}
+
+/*
+ * vmbus_establish_gpadl - Estabish a GPADL for the specified buffer
+ *
+ * @channel: a channel
+ * @kbuffer: from kmalloc
+ * @size: page-size multiple
+ * @gpadl_handle: some funky thing
+ */
+int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
+                               u32 size, u32 *gpadl_handle)
+{
+        struct vmbus_channel_gpadl_header *gpadlmsg;
+        struct vmbus_channel_gpadl_body *gpadl_body;
+        /* struct vmbus_channel_gpadl_created *gpadlCreated; */
+        struct vmbus_channel_msginfo *msginfo = NULL;
+        struct vmbus_channel_msginfo *submsginfo;
+        u32 msgcount;
+        struct list_head *curr;
+        u32 next_gpadl_handle;
+        unsigned long flags;
+        int ret = 0;
+        int t;
+
+        next_gpadl_handle = atomic_read(&vmbus_connection.next_gpadl_handle);
+        atomic_inc(&vmbus_connection.next_gpadl_handle);
+
+        ret = create_gpadl_header(kbuffer, size, &msginfo, &msgcount);
+        if (ret)
+                return ret;
+
+        init_completion(&msginfo->waitevent);
+
+        gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg;
+        gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER;
+        gpadlmsg->child_relid = channel->offermsg.child_relid;
+        gpadlmsg->gpadl = next_gpadl_handle;
+
+        dump_gpadl_header(gpadlmsg);
+
+        spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
+        list_add_tail(&msginfo->msglistentry,
+                      &vmbus_connection.chn_msg_list);
+
+        spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
+
+        ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize -
+                               sizeof(*msginfo));
+        if (ret != 0)
+                goto cleanup;
+
+        if (msgcount > 1) {
+                list_for_each(curr, &msginfo->submsglist) {
+
+                        submsginfo = (struct vmbus_channel_msginfo *)curr;
+                        gpadl_body =
+                             (struct vmbus_channel_gpadl_body *)submsginfo->msg;
+
+                        gpadl_body->header.msgtype =
+                                CHANNELMSG_GPADL_BODY;
+                        gpadl_body->gpadl = next_gpadl_handle;
+
+                        dump_gpadl_body(gpadl_body, submsginfo->msgsize -
+                                      sizeof(*submsginfo));
+                        ret = vmbus_post_msg(gpadl_body,
+                                               submsginfo->msgsize -
+                                               sizeof(*submsginfo));
+                        if (ret != 0)
+                                goto cleanup;
+
+                }
+        }
+        t = wait_for_completion_timeout(&msginfo->waitevent, 5*HZ);
+        BUG_ON(t == 0);
+
+
+        /* At this point, we received the gpadl created msg */
+        *gpadl_handle = gpadlmsg->gpadl;
+
+cleanup:
+        spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
+        list_del(&msginfo->msglistentry);
+        spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
+
+        kfree(msginfo);
+        return ret;
+}
+EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
+
+/*
+ * vmbus_teardown_gpadl -Teardown the specified GPADL handle
+ */
+int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
+{
+        struct vmbus_channel_gpadl_teardown *msg;
+        struct vmbus_channel_msginfo *info;
+        unsigned long flags;
+        int ret, t;
+
+        /* ASSERT(gpadl_handle != 0); */
+
+        info = kmalloc(sizeof(*info) +
+                       sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
+        if (!info)
+                return -ENOMEM;
+
+        init_completion(&info->waitevent);
+
+        msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
+
+        msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
+        msg->child_relid = channel->offermsg.child_relid;
+        msg->gpadl = gpadl_handle;
+
+        spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
+        list_add_tail(&info->msglistentry,
+                      &vmbus_connection.chn_msg_list);
+        spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
+        ret = vmbus_post_msg(msg,
+                               sizeof(struct vmbus_channel_gpadl_teardown));
+
+        BUG_ON(ret != 0);
+        t = wait_for_completion_timeout(&info->waitevent, 5*HZ);
+        BUG_ON(t == 0);
+
+        /* Received a torndown response */
+        spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
+        list_del(&info->msglistentry);
+        spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
+
+        kfree(info);
+        return ret;
+}
+EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
+
+/*
+ * vmbus_close - Close the specified channel
+ */
+void vmbus_close(struct vmbus_channel *channel)
+{
+        struct vmbus_channel_close_channel *msg;
+        int ret;
+
+        /* Stop callback and cancel the timer asap */
+        channel->onchannel_callback = NULL;
+
+        /* Send a closing message */
+
+        msg = &channel->close_msg.msg;
+
+        msg->header.msgtype = CHANNELMSG_CLOSECHANNEL;
+        msg->child_relid = channel->offermsg.child_relid;
+
+        ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel));
+
+        BUG_ON(ret != 0);
+        /* Tear down the gpadl for the channel's ring buffer */
+        if (channel->ringbuffer_gpadlhandle)
+                vmbus_teardown_gpadl(channel,
+                                          channel->ringbuffer_gpadlhandle);
+
+        /* Cleanup the ring buffers for this channel */
+        hv_ringbuffer_cleanup(&channel->outbound);
+        hv_ringbuffer_cleanup(&channel->inbound);
+
+        free_pages((unsigned long)channel->ringbuffer_pages,
+                get_order(channel->ringbuffer_pagecount * PAGE_SIZE));
+
+
+}
+EXPORT_SYMBOL_GPL(vmbus_close);
+
+/**
+ * vmbus_sendpacket() - Send the specified buffer on the given channel
+ * @channel: Pointer to vmbus_channel structure.
+ * @buffer: Pointer to the buffer you want to receive the data into.
+ * @bufferlen: Maximum size of what the the buffer will hold
+ * @requestid: Identifier of the request
+ * @type: Type of packet that is being send e.g. negotiate, time
+ * packet etc.
+ *
+ * Sends data in @buffer directly to hyper-v via the vmbus
+ * This will send the data unparsed to hyper-v.
+ *
+ * Mainly used by Hyper-V drivers.
+ */
+int vmbus_sendpacket(struct vmbus_channel *channel, const void *buffer,
+                           u32 bufferlen, u64 requestid,
+                           enum vmbus_packet_type type, u32 flags)
+{
+        struct vmpacket_descriptor desc;
+        u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
+        u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
+        struct scatterlist bufferlist[3];
+        u64 aligned_data = 0;
+        int ret;
+
+
+        /* Setup the descriptor */
+        desc.type = type; /* VmbusPacketTypeDataInBand; */
+        desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
+        /* in 8-bytes granularity */
+        desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
+        desc.len8 = (u16)(packetlen_aligned >> 3);
+        desc.trans_id = requestid;
+
+        sg_init_table(bufferlist, 3);
+        sg_set_buf(&bufferlist[0], &desc, sizeof(struct vmpacket_descriptor));
+        sg_set_buf(&bufferlist[1], buffer, bufferlen);
+        sg_set_buf(&bufferlist[2], &aligned_data,
+                   packetlen_aligned - packetlen);
+
+        ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3);
+
+        if (ret == 0 && !hv_get_ringbuffer_interrupt_mask(&channel->outbound))
+                vmbus_setevent(channel);
+
+        return ret;
+}
+EXPORT_SYMBOL(vmbus_sendpacket);
+
+/*
+ * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer
+ * packets using a GPADL Direct packet type.
+ */
+int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
+                                     struct hv_page_buffer pagebuffers[],
+                                     u32 pagecount, void *buffer, u32 bufferlen,
+                                     u64 requestid)
+{
+        int ret;
+        int i;
+        struct vmbus_channel_packet_page_buffer desc;
+        u32 descsize;
+        u32 packetlen;
+        u32 packetlen_aligned;
+        struct scatterlist bufferlist[3];
+        u64 aligned_data = 0;
+
+        if (pagecount > MAX_PAGE_BUFFER_COUNT)
+                return -EINVAL;
+
+
+        /*
+         * Adjust the size down since vmbus_channel_packet_page_buffer is the
+         * largest size we support
+         */
+        descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
+                          ((MAX_PAGE_BUFFER_COUNT - pagecount) *
+                          sizeof(struct hv_page_buffer));
+        packetlen = descsize + bufferlen;
+        packetlen_aligned = ALIGN(packetlen, sizeof(u64));
+
+        /* Setup the descriptor */
+        desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
+        desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
+        desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
+        desc.length8 = (u16)(packetlen_aligned >> 3);
+        desc.transactionid = requestid;
+        desc.rangecount = pagecount;
+
+        for (i = 0; i < pagecount; i++) {
+                desc.range[i].len = pagebuffers[i].len;
+                desc.range[i].offset = pagebuffers[i].offset;
+                desc.range[i].pfn        = pagebuffers[i].pfn;
+        }
+
+        sg_init_table(bufferlist, 3);
+        sg_set_buf(&bufferlist[0], &desc, descsize);
+        sg_set_buf(&bufferlist[1], buffer, bufferlen);
+        sg_set_buf(&bufferlist[2], &aligned_data,
+                packetlen_aligned - packetlen);
+
+        ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3);
+
+        if (ret == 0 && !hv_get_ringbuffer_interrupt_mask(&channel->outbound))
+                vmbus_setevent(channel);
+
+        return ret;
+}
+EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
+
+/*
+ * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
+ * using a GPADL Direct packet type.
+ */
+int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
+                                struct hv_multipage_buffer *multi_pagebuffer,
+                                void *buffer, u32 bufferlen, u64 requestid)
+{
+        int ret;
+        struct vmbus_channel_packet_multipage_buffer desc;
+        u32 descsize;
+        u32 packetlen;
+        u32 packetlen_aligned;
+        struct scatterlist bufferlist[3];
+        u64 aligned_data = 0;
+        u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
+                                         multi_pagebuffer->len);
+
+
+        if ((pfncount < 0) || (pfncount > MAX_MULTIPAGE_BUFFER_COUNT))
+                return -EINVAL;
+
+        /*
+         * Adjust the size down since vmbus_channel_packet_multipage_buffer is
+         * the largest size we support
+         */
+        descsize = sizeof(struct vmbus_channel_packet_multipage_buffer) -
+                          ((MAX_MULTIPAGE_BUFFER_COUNT - pfncount) *
+                          sizeof(u64));
+        packetlen = descsize + bufferlen;
+        packetlen_aligned = ALIGN(packetlen, sizeof(u64));
+
+
+        /* Setup the descriptor */
+        desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
+        desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
+        desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
+        desc.length8 = (u16)(packetlen_aligned >> 3);
+        desc.transactionid = requestid;
+        desc.rangecount = 1;
+
+        desc.range.len = multi_pagebuffer->len;
+        desc.range.offset = multi_pagebuffer->offset;
+
+        memcpy(desc.range.pfn_array, multi_pagebuffer->pfn_array,
+               pfncount * sizeof(u64));
+
+        sg_init_table(bufferlist, 3);
+        sg_set_buf(&bufferlist[0], &desc, descsize);
+        sg_set_buf(&bufferlist[1], buffer, bufferlen);
+        sg_set_buf(&bufferlist[2], &aligned_data,
+                packetlen_aligned - packetlen);
+
+        ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3);
+
+        if (ret == 0 && !hv_get_ringbuffer_interrupt_mask(&channel->outbound))
+                vmbus_setevent(channel);
+
+        return ret;
+}
+EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
+
+/**
+ * vmbus_recvpacket() - Retrieve the user packet on the specified channel
+ * @channel: Pointer to vmbus_channel structure.
+ * @buffer: Pointer to the buffer you want to receive the data into.
+ * @bufferlen: Maximum size of what the the buffer will hold
+ * @buffer_actual_len: The actual size of the data after it was received
+ * @requestid: Identifier of the request
+ *
+ * Receives directly from the hyper-v vmbus and puts the data it received
+ * into Buffer. This will receive the data unparsed from hyper-v.
+ *
+ * Mainly used by Hyper-V drivers.
+ */
+int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
+                        u32 bufferlen, u32 *buffer_actual_len, u64 *requestid)
+{
+        struct vmpacket_descriptor desc;
+        u32 packetlen;
+        u32 userlen;
+        int ret;
+        unsigned long flags;
+
+        *buffer_actual_len = 0;
+        *requestid = 0;
+
+        spin_lock_irqsave(&channel->inbound_lock, flags);
+
+        ret = hv_ringbuffer_peek(&channel->inbound, &desc,
+                             sizeof(struct vmpacket_descriptor));
+        if (ret != 0) {
+                spin_unlock_irqrestore(&channel->inbound_lock, flags);
+                return 0;
+        }
+
+        packetlen = desc.len8 << 3;
+        userlen = packetlen - (desc.offset8 << 3);
+
+        *buffer_actual_len = userlen;
+
+        if (userlen > bufferlen) {
+                spin_unlock_irqrestore(&channel->inbound_lock, flags);
+
+                pr_err("Buffer too small - got %d needs %d\n",
+                           bufferlen, userlen);
+                return -ETOOSMALL;
+        }
+
+        *requestid = desc.trans_id;
+
+        /* Copy over the packet to the user buffer */
+        ret = hv_ringbuffer_read(&channel->inbound, buffer, userlen,
+                             (desc.offset8 << 3));
+
+        spin_unlock_irqrestore(&channel->inbound_lock, flags);
+
+        return 0;
+}
+EXPORT_SYMBOL(vmbus_recvpacket);
+
+/*
+ * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel
+ */
+int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
+                              u32 bufferlen, u32 *buffer_actual_len,
+                              u64 *requestid)
+{
+        struct vmpacket_descriptor desc;
+        u32 packetlen;
+        u32 userlen;
+        int ret;
+        unsigned long flags;
+
+        *buffer_actual_len = 0;
+        *requestid = 0;
+
+        spin_lock_irqsave(&channel->inbound_lock, flags);
+
+        ret = hv_ringbuffer_peek(&channel->inbound, &desc,
+                             sizeof(struct vmpacket_descriptor));
+        if (ret != 0) {
+                spin_unlock_irqrestore(&channel->inbound_lock, flags);
+                return 0;
+        }
+
+
+        packetlen = desc.len8 << 3;
+        userlen = packetlen - (desc.offset8 << 3);
+
+        *buffer_actual_len = packetlen;
+
+        if (packetlen > bufferlen) {
+                spin_unlock_irqrestore(&channel->inbound_lock, flags);
+
+                pr_err("Buffer too small - needed %d bytes but "
+                        "got space for only %d bytes\n",
+                        packetlen, bufferlen);
+                return -2;
+        }
+
+        *requestid = desc.trans_id;
+
+        /* Copy over the entire packet to the user buffer */
+        ret = hv_ringbuffer_read(&channel->inbound, buffer, packetlen, 0);
+
+        spin_unlock_irqrestore(&channel->inbound_lock, flags);
+        return 0;
+}
+EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);