Merge branch 'staging-next' into Linux 3.1

This was done to resolve a conflict in the
drivers/staging/comedi/drivers/ni_labpc.c file that resolved a build
bugfix in Linus's tree with a "better" bugfix that was in the
staging-next tree that resolved the issue in a more complete manner.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

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..650c9f0b6642
--- /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 <asm/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();
+}