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-rw-r--r--drivers/hv/channel.c815
1 files changed, 815 insertions, 0 deletions
diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
new file mode 100644
index 0000000..4065374
--- /dev/null
+++ b/drivers/hv/channel.c
@@ -0,0 +1,815 @@
+/*
+ * 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 <linux/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;
+
+ debuginfo->relid = channel->offermsg.child_relid;
+ debuginfo->state = channel->state;
+ memcpy(&debuginfo->interfacetype,
+ &channel->offermsg.offer.if_type, sizeof(uuid_le));
+ memcpy(&debuginfo->interface_instance,
+ &channel->offermsg.offer.if_instance,
+ sizeof(uuid_le));
+
+ 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 *open_msg;
+ struct vmbus_channel_msginfo *open_info = 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 */
+ open_info = kmalloc(sizeof(*open_info) +
+ sizeof(struct vmbus_channel_open_channel),
+ GFP_KERNEL);
+ if (!open_info) {
+ err = -ENOMEM;
+ goto errorout;
+ }
+
+ init_completion(&open_info->waitevent);
+
+ open_msg = (struct vmbus_channel_open_channel *)open_info->msg;
+ open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL;
+ open_msg->openid = newchannel->offermsg.child_relid;
+ open_msg->child_relid = newchannel->offermsg.child_relid;
+ open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
+ open_msg->downstream_ringbuffer_pageoffset = send_ringbuffer_size >>
+ PAGE_SHIFT;
+ open_msg->server_contextarea_gpadlhandle = 0;
+
+ if (userdatalen > MAX_USER_DEFINED_BYTES) {
+ err = -EINVAL;
+ goto errorout;
+ }
+
+ if (userdatalen)
+ memcpy(open_msg->userdata, userdata, userdatalen);
+
+ spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
+ list_add_tail(&open_info->msglistentry,
+ &vmbus_connection.chn_msg_list);
+ spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
+
+ ret = vmbus_post_msg(open_msg,
+ sizeof(struct vmbus_channel_open_channel));
+
+ if (ret != 0)
+ goto cleanup;
+
+ t = wait_for_completion_timeout(&open_info->waitevent, 5*HZ);
+ if (t == 0) {
+ err = -ETIMEDOUT;
+ goto errorout;
+ }
+
+
+ if (open_info->response.open_result.status)
+ err = open_info->response.open_result.status;
+
+cleanup:
+ spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
+ list_del(&open_info->msglistentry);
+ spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
+
+ kfree(open_info);
+ 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(open_info);
+ return err;
+}
+EXPORT_SYMBOL_GPL(vmbus_open);
+
+/*
+ * 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_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;
+
+
+ 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;
+
+ 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;
+
+ 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;
+ unsigned long flags;
+
+ /* Stop callback and cancel the timer asap */
+ spin_lock_irqsave(&channel->inbound_lock, flags);
+ channel->onchannel_callback = NULL;
+ spin_unlock_irqrestore(&channel->inbound_lock, flags);
+
+ /* 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;
+
+ *buffer_actual_len = 0;
+ *requestid = 0;
+
+
+ ret = hv_ringbuffer_peek(&channel->inbound, &desc,
+ sizeof(struct vmpacket_descriptor));
+ if (ret != 0)
+ return 0;
+
+ packetlen = desc.len8 << 3;
+ userlen = packetlen - (desc.offset8 << 3);
+
+ *buffer_actual_len = userlen;
+
+ if (userlen > bufferlen) {
+
+ 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));
+
+
+ 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;
+
+ *buffer_actual_len = 0;
+ *requestid = 0;
+
+
+ ret = hv_ringbuffer_peek(&channel->inbound, &desc,
+ sizeof(struct vmpacket_descriptor));
+ if (ret != 0)
+ return 0;
+
+
+ packetlen = desc.len8 << 3;
+ userlen = packetlen - (desc.offset8 << 3);
+
+ *buffer_actual_len = packetlen;
+
+ if (packetlen > bufferlen) {
+ pr_err("Buffer too small - needed %d bytes but "
+ "got space for only %d bytes\n",
+ packetlen, bufferlen);
+ return -ENOBUFS;
+ }
+
+ *requestid = desc.trans_id;
+
+ /* Copy over the entire packet to the user buffer */
+ ret = hv_ringbuffer_read(&channel->inbound, buffer, packetlen, 0);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);
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