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-rw-r--r--drivers/hv/connection.c318
1 files changed, 318 insertions, 0 deletions
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
new file mode 100644
index 000000000000..5f438b650068
--- /dev/null
+++ b/drivers/hv/connection.c
@@ -0,0 +1,318 @@
+/*
+ *
+ * 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/delay.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/hyperv.h>
+
+#include "hyperv_vmbus.h"
+
+
+struct vmbus_connection vmbus_connection = {
+ .conn_state = DISCONNECTED,
+ .next_gpadl_handle = ATOMIC_INIT(0xE1E10),
+};
+
+/*
+ * vmbus_connect - Sends a connect request on the partition service connection
+ */
+int vmbus_connect(void)
+{
+ int ret = 0;
+ int t;
+ struct vmbus_channel_msginfo *msginfo = NULL;
+ struct vmbus_channel_initiate_contact *msg;
+ unsigned long flags;
+
+ /* Initialize the vmbus connection */
+ vmbus_connection.conn_state = CONNECTING;
+ vmbus_connection.work_queue = create_workqueue("hv_vmbus_con");
+ if (!vmbus_connection.work_queue) {
+ ret = -ENOMEM;
+ goto cleanup;
+ }
+
+ INIT_LIST_HEAD(&vmbus_connection.chn_msg_list);
+ spin_lock_init(&vmbus_connection.channelmsg_lock);
+
+ INIT_LIST_HEAD(&vmbus_connection.chn_list);
+ spin_lock_init(&vmbus_connection.channel_lock);
+
+ /*
+ * Setup the vmbus event connection for channel interrupt
+ * abstraction stuff
+ */
+ vmbus_connection.int_page =
+ (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, 0);
+ if (vmbus_connection.int_page == NULL) {
+ ret = -ENOMEM;
+ goto cleanup;
+ }
+
+ vmbus_connection.recv_int_page = vmbus_connection.int_page;
+ vmbus_connection.send_int_page =
+ (void *)((unsigned long)vmbus_connection.int_page +
+ (PAGE_SIZE >> 1));
+
+ /*
+ * Setup the monitor notification facility. The 1st page for
+ * parent->child and the 2nd page for child->parent
+ */
+ vmbus_connection.monitor_pages =
+ (void *)__get_free_pages((GFP_KERNEL|__GFP_ZERO), 1);
+ if (vmbus_connection.monitor_pages == NULL) {
+ ret = -ENOMEM;
+ goto cleanup;
+ }
+
+ msginfo = kzalloc(sizeof(*msginfo) +
+ sizeof(struct vmbus_channel_initiate_contact),
+ GFP_KERNEL);
+ if (msginfo == NULL) {
+ ret = -ENOMEM;
+ goto cleanup;
+ }
+
+ init_completion(&msginfo->waitevent);
+
+ msg = (struct vmbus_channel_initiate_contact *)msginfo->msg;
+
+ msg->header.msgtype = CHANNELMSG_INITIATE_CONTACT;
+ msg->vmbus_version_requested = VMBUS_REVISION_NUMBER;
+ msg->interrupt_page = virt_to_phys(vmbus_connection.int_page);
+ msg->monitor_page1 = virt_to_phys(vmbus_connection.monitor_pages);
+ msg->monitor_page2 = virt_to_phys(
+ (void *)((unsigned long)vmbus_connection.monitor_pages +
+ PAGE_SIZE));
+
+ /*
+ * Add to list before we send the request since we may
+ * receive the response before returning from this routine
+ */
+ 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(msg,
+ sizeof(struct vmbus_channel_initiate_contact));
+ if (ret != 0) {
+ spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
+ list_del(&msginfo->msglistentry);
+ spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock,
+ flags);
+ goto cleanup;
+ }
+
+ /* Wait for the connection response */
+ t = wait_for_completion_timeout(&msginfo->waitevent, 5*HZ);
+ if (t == 0) {
+ spin_lock_irqsave(&vmbus_connection.channelmsg_lock,
+ flags);
+ list_del(&msginfo->msglistentry);
+ spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock,
+ flags);
+ ret = -ETIMEDOUT;
+ goto cleanup;
+ }
+
+ spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
+ list_del(&msginfo->msglistentry);
+ spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
+
+ /* Check if successful */
+ if (msginfo->response.version_response.version_supported) {
+ vmbus_connection.conn_state = CONNECTED;
+ } else {
+ pr_err("Unable to connect, "
+ "Version %d not supported by Hyper-V\n",
+ VMBUS_REVISION_NUMBER);
+ ret = -ECONNREFUSED;
+ goto cleanup;
+ }
+
+ kfree(msginfo);
+ return 0;
+
+cleanup:
+ vmbus_connection.conn_state = DISCONNECTED;
+
+ if (vmbus_connection.work_queue)
+ destroy_workqueue(vmbus_connection.work_queue);
+
+ if (vmbus_connection.int_page) {
+ free_pages((unsigned long)vmbus_connection.int_page, 0);
+ vmbus_connection.int_page = NULL;
+ }
+
+ if (vmbus_connection.monitor_pages) {
+ free_pages((unsigned long)vmbus_connection.monitor_pages, 1);
+ vmbus_connection.monitor_pages = NULL;
+ }
+
+ kfree(msginfo);
+
+ return ret;
+}
+
+
+/*
+ * relid2channel - Get the channel object given its
+ * child relative id (ie channel id)
+ */
+struct vmbus_channel *relid2channel(u32 relid)
+{
+ struct vmbus_channel *channel;
+ struct vmbus_channel *found_channel = NULL;
+ unsigned long flags;
+
+ spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
+ list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
+ if (channel->offermsg.child_relid == relid) {
+ found_channel = channel;
+ break;
+ }
+ }
+ spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
+
+ return found_channel;
+}
+
+/*
+ * process_chn_event - Process a channel event notification
+ */
+static void process_chn_event(u32 relid)
+{
+ struct vmbus_channel *channel;
+ unsigned long flags;
+
+ /*
+ * Find the channel based on this relid and invokes the
+ * channel callback to process the event
+ */
+ channel = relid2channel(relid);
+
+ if (!channel) {
+ pr_err("channel not found for relid - %u\n", relid);
+ return;
+ }
+
+ /*
+ * A channel once created is persistent even when there
+ * is no driver handling the device. An unloading driver
+ * sets the onchannel_callback to NULL under the
+ * protection of the channel inbound_lock. Thus, checking
+ * and invoking the driver specific callback takes care of
+ * orderly unloading of the driver.
+ */
+
+ spin_lock_irqsave(&channel->inbound_lock, flags);
+ if (channel->onchannel_callback != NULL)
+ channel->onchannel_callback(channel->channel_callback_context);
+ else
+ pr_err("no channel callback for relid - %u\n", relid);
+
+ spin_unlock_irqrestore(&channel->inbound_lock, flags);
+}
+
+/*
+ * vmbus_on_event - Handler for events
+ */
+void vmbus_on_event(unsigned long data)
+{
+ u32 dword;
+ u32 maxdword = MAX_NUM_CHANNELS_SUPPORTED >> 5;
+ int bit;
+ u32 relid;
+ u32 *recv_int_page = vmbus_connection.recv_int_page;
+
+ /* Check events */
+ if (!recv_int_page)
+ return;
+ for (dword = 0; dword < maxdword; dword++) {
+ if (!recv_int_page[dword])
+ continue;
+ for (bit = 0; bit < 32; bit++) {
+ if (sync_test_and_clear_bit(bit,
+ (unsigned long *)&recv_int_page[dword])) {
+ relid = (dword << 5) + bit;
+
+ if (relid == 0)
+ /*
+ * Special case - vmbus
+ * channel protocol msg
+ */
+ continue;
+
+ process_chn_event(relid);
+ }
+ }
+ }
+}
+
+/*
+ * vmbus_post_msg - Send a msg on the vmbus's message connection
+ */
+int vmbus_post_msg(void *buffer, size_t buflen)
+{
+ union hv_connection_id conn_id;
+ int ret = 0;
+ int retries = 0;
+
+ conn_id.asu32 = 0;
+ conn_id.u.id = VMBUS_MESSAGE_CONNECTION_ID;
+
+ /*
+ * hv_post_message() can have transient failures because of
+ * insufficient resources. Retry the operation a couple of
+ * times before giving up.
+ */
+ while (retries < 3) {
+ ret = hv_post_message(conn_id, 1, buffer, buflen);
+ if (ret != HV_STATUS_INSUFFICIENT_BUFFERS)
+ return ret;
+ retries++;
+ msleep(100);
+ }
+ return ret;
+}
+
+/*
+ * vmbus_set_event - Send an event notification to the parent
+ */
+int vmbus_set_event(u32 child_relid)
+{
+ /* Each u32 represents 32 channels */
+ sync_set_bit(child_relid & 31,
+ (unsigned long *)vmbus_connection.send_int_page +
+ (child_relid >> 5));
+
+ return hv_signal_event();
+}