Merge branch 'x86/asm' into x86/apic, to resolve a conflict
[firefly-linux-kernel-4.4.55.git] / drivers / hv / channel_mgmt.c
index bb39705a89d961d1a9decbe0bc01889d26ccc9e7..0eeb1b3bc0484ce75572b0f6326ca0857cb73268 100644 (file)
@@ -23,7 +23,6 @@
 #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/list.h>
 
 #include "hyperv_vmbus.h"
 
-struct vmbus_channel_message_table_entry {
-       enum vmbus_channel_message_type message_type;
-       void (*message_handler)(struct vmbus_channel_message_header *msg);
-};
-
-struct vmbus_rescind_work {
-       struct work_struct work;
-       struct vmbus_channel *channel;
-};
-
 /**
  * vmbus_prep_negotiate_resp() - Create default response for Hyper-V Negotiate message
  * @icmsghdrp: Pointer to msg header structure
@@ -139,20 +128,6 @@ fw_error:
 
 EXPORT_SYMBOL_GPL(vmbus_prep_negotiate_resp);
 
-static void vmbus_sc_creation_cb(struct work_struct *work)
-{
-       struct vmbus_channel *newchannel = container_of(work,
-                                                       struct vmbus_channel,
-                                                       work);
-       struct vmbus_channel *primary_channel = newchannel->primary_channel;
-
-       /*
-        * On entry sc_creation_callback has been already verified to
-        * be non-NULL.
-        */
-       primary_channel->sc_creation_callback(newchannel);
-}
-
 /*
  * alloc_channel - Allocate and initialize a vmbus channel object
  */
@@ -172,77 +147,15 @@ static struct vmbus_channel *alloc_channel(void)
        INIT_LIST_HEAD(&channel->sc_list);
        INIT_LIST_HEAD(&channel->percpu_list);
 
-       channel->controlwq = alloc_workqueue("hv_vmbus_ctl/%d", WQ_MEM_RECLAIM,
-                                            1, channel->id);
-       if (!channel->controlwq) {
-               kfree(channel);
-               return NULL;
-       }
-
        return channel;
 }
 
-/*
- * release_hannel - Release the vmbus channel object itself
- */
-static void release_channel(struct work_struct *work)
-{
-       struct vmbus_channel *channel = container_of(work,
-                                                    struct vmbus_channel,
-                                                    work);
-
-       destroy_workqueue(channel->controlwq);
-
-       kfree(channel);
-}
-
 /*
  * free_channel - Release the resources used by the vmbus channel object
  */
 static void free_channel(struct vmbus_channel *channel)
 {
-
-       /*
-        * We have to release the channel's workqueue/thread in the vmbus's
-        * workqueue/thread context
-        * ie we can't destroy ourselves.
-        */
-       INIT_WORK(&channel->work, release_channel);
-       queue_work(vmbus_connection.work_queue, &channel->work);
-}
-
-static void process_rescind_fn(struct work_struct *work)
-{
-       struct vmbus_rescind_work *rc_work;
-       struct vmbus_channel *channel;
-       struct device *dev;
-
-       rc_work = container_of(work, struct vmbus_rescind_work, work);
-       channel = rc_work->channel;
-
-       /*
-        * We have already acquired a reference on the channel
-        * and so it cannot vanish underneath us.
-        * It is possible (while very unlikely) that we may
-        * get here while the processing of the initial offer
-        * is still not complete. Deal with this situation by
-        * just waiting until the channel is in the correct state.
-        */
-
-       while (channel->work.func != release_channel)
-               msleep(1000);
-
-       if (channel->device_obj) {
-               dev = get_device(&channel->device_obj->device);
-               if (dev) {
-                       vmbus_device_unregister(channel->device_obj);
-                       put_device(dev);
-               }
-       } else {
-               hv_process_channel_removal(channel,
-                                          channel->offermsg.child_relid);
-       }
-       kfree(work);
+       kfree(channel);
 }
 
 static void percpu_channel_enq(void *arg)
@@ -307,46 +220,6 @@ void vmbus_free_channels(void)
        }
 }
 
-static void vmbus_do_device_register(struct work_struct *work)
-{
-       struct hv_device *device_obj;
-       int ret;
-       unsigned long flags;
-       struct vmbus_channel *newchannel = container_of(work,
-                                                    struct vmbus_channel,
-                                                    work);
-
-       ret = vmbus_device_register(newchannel->device_obj);
-       if (ret != 0) {
-               pr_err("unable to add child device object (relid %d)\n",
-                       newchannel->offermsg.child_relid);
-               spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
-               list_del(&newchannel->listentry);
-               device_obj = newchannel->device_obj;
-               newchannel->device_obj = NULL;
-               spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
-
-               if (newchannel->target_cpu != get_cpu()) {
-                       put_cpu();
-                       smp_call_function_single(newchannel->target_cpu,
-                                        percpu_channel_deq, newchannel, true);
-               } else {
-                       percpu_channel_deq(newchannel);
-                       put_cpu();
-               }
-
-               kfree(device_obj);
-               if (!newchannel->rescind) {
-                       free_channel(newchannel);
-                       return;
-               }
-       }
-       /*
-        * The next state for this channel is to be freed.
-        */
-       INIT_WORK(&newchannel->work, release_channel);
-}
-
 /*
  * vmbus_process_offer - Process the offer by creating a channel/device
  * associated with this offer
@@ -415,19 +288,8 @@ static void vmbus_process_offer(struct vmbus_channel *newchannel)
 
                        newchannel->state = CHANNEL_OPEN_STATE;
                        channel->num_sc++;
-                       if (channel->sc_creation_callback != NULL) {
-                               /*
-                                * We need to invoke the sub-channel creation
-                                * callback; invoke this in a seperate work
-                                * context since we are currently running on
-                                * the global work context in which we handle
-                                * messages from the host.
-                                */
-                               INIT_WORK(&newchannel->work,
-                                         vmbus_sc_creation_cb);
-                               queue_work(newchannel->controlwq,
-                                          &newchannel->work);
-                       }
+                       if (channel->sc_creation_callback != NULL)
+                               channel->sc_creation_callback(newchannel);
 
                        return;
                }
@@ -458,13 +320,13 @@ static void vmbus_process_offer(struct vmbus_channel *newchannel)
         * Add the new device to the bus. This will kick off device-driver
         * binding which eventually invokes the device driver's AddDevice()
         * method.
-        * Invoke this call on the per-channel work context.
-        * Until we return from this function, rescind offer message
-        * cannot be processed as we are running on the global message
-        * handling work.
         */
-       INIT_WORK(&newchannel->work, vmbus_do_device_register);
-       queue_work(newchannel->controlwq, &newchannel->work);
+       if (vmbus_device_register(newchannel->device_obj) != 0) {
+               pr_err("unable to add child device object (relid %d)\n",
+                       newchannel->offermsg.child_relid);
+               kfree(newchannel->device_obj);
+               goto err_deq_chan;
+       }
        return;
 
 err_deq_chan:
@@ -618,31 +480,35 @@ static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr)
 {
        struct vmbus_channel_rescind_offer *rescind;
        struct vmbus_channel *channel;
-       struct vmbus_rescind_work *rc_work;
+       unsigned long flags;
+       struct device *dev;
 
        rescind = (struct vmbus_channel_rescind_offer *)hdr;
-       channel = relid2channel(rescind->child_relid, true);
+       channel = relid2channel(rescind->child_relid);
 
        if (channel == NULL) {
                hv_process_channel_removal(NULL, rescind->child_relid);
                return;
        }
 
-       /*
-        * We have acquired a reference on the channel and have posted
-        * the rescind state. Perform further cleanup in a work context
-        * that is different from the global work context in which
-        * we process messages from the host (we are currently executing
-        * on that global context.
-        */
-       rc_work = kzalloc(sizeof(struct vmbus_rescind_work), GFP_KERNEL);
-       if (!rc_work) {
-               pr_err("Unable to allocate memory for rescind processing ");
-               return;
+       spin_lock_irqsave(&channel->lock, flags);
+       channel->rescind = true;
+       spin_unlock_irqrestore(&channel->lock, flags);
+
+       if (channel->device_obj) {
+               /*
+                * We will have to unregister this device from the
+                * driver core.
+                */
+               dev = get_device(&channel->device_obj->device);
+               if (dev) {
+                       vmbus_device_unregister(channel->device_obj);
+                       put_device(dev);
+               }
+       } else {
+               hv_process_channel_removal(channel,
+                       channel->offermsg.child_relid);
        }
-       rc_work->channel = channel;
-       INIT_WORK(&rc_work->work, process_rescind_fn);
-       schedule_work(&rc_work->work);
 }
 
 /*
@@ -827,25 +693,25 @@ static void vmbus_onversion_response(
 }
 
 /* Channel message dispatch table */
-static struct vmbus_channel_message_table_entry
+struct vmbus_channel_message_table_entry
        channel_message_table[CHANNELMSG_COUNT] = {
-       {CHANNELMSG_INVALID,                    NULL},
-       {CHANNELMSG_OFFERCHANNEL,               vmbus_onoffer},
-       {CHANNELMSG_RESCIND_CHANNELOFFER,       vmbus_onoffer_rescind},
-       {CHANNELMSG_REQUESTOFFERS,              NULL},
-       {CHANNELMSG_ALLOFFERS_DELIVERED,        vmbus_onoffers_delivered},
-       {CHANNELMSG_OPENCHANNEL,                NULL},
-       {CHANNELMSG_OPENCHANNEL_RESULT, vmbus_onopen_result},
-       {CHANNELMSG_CLOSECHANNEL,               NULL},
-       {CHANNELMSG_GPADL_HEADER,               NULL},
-       {CHANNELMSG_GPADL_BODY,         NULL},
-       {CHANNELMSG_GPADL_CREATED,              vmbus_ongpadl_created},
-       {CHANNELMSG_GPADL_TEARDOWN,             NULL},
-       {CHANNELMSG_GPADL_TORNDOWN,             vmbus_ongpadl_torndown},
-       {CHANNELMSG_RELID_RELEASED,             NULL},
-       {CHANNELMSG_INITIATE_CONTACT,           NULL},
-       {CHANNELMSG_VERSION_RESPONSE,           vmbus_onversion_response},
-       {CHANNELMSG_UNLOAD,                     NULL},
+       {CHANNELMSG_INVALID,                    0, NULL},
+       {CHANNELMSG_OFFERCHANNEL,               0, vmbus_onoffer},
+       {CHANNELMSG_RESCIND_CHANNELOFFER,       0, vmbus_onoffer_rescind},
+       {CHANNELMSG_REQUESTOFFERS,              0, NULL},
+       {CHANNELMSG_ALLOFFERS_DELIVERED,        1, vmbus_onoffers_delivered},
+       {CHANNELMSG_OPENCHANNEL,                0, NULL},
+       {CHANNELMSG_OPENCHANNEL_RESULT,         1, vmbus_onopen_result},
+       {CHANNELMSG_CLOSECHANNEL,               0, NULL},
+       {CHANNELMSG_GPADL_HEADER,               0, NULL},
+       {CHANNELMSG_GPADL_BODY,                 0, NULL},
+       {CHANNELMSG_GPADL_CREATED,              1, vmbus_ongpadl_created},
+       {CHANNELMSG_GPADL_TEARDOWN,             0, NULL},
+       {CHANNELMSG_GPADL_TORNDOWN,             1, vmbus_ongpadl_torndown},
+       {CHANNELMSG_RELID_RELEASED,             0, NULL},
+       {CHANNELMSG_INITIATE_CONTACT,           0, NULL},
+       {CHANNELMSG_VERSION_RESPONSE,           1, vmbus_onversion_response},
+       {CHANNELMSG_UNLOAD,                     0, NULL},
 };
 
 /*