Staging: hv: move hyperv code out of staging directory

After many years wandering the desert, it is finally time for the
Microsoft HyperV code to move out of the staging directory.  Or at least
the core hyperv bus code, and the utility driver, the rest still have
some review to get through by the various subsystem maintainers.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>

1 files changed, 318 insertions, 0 deletions

diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
new file mode 100644
index 0000000..5f438b6
--- /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();
+}