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path: root/drivers/hv/channel_mgmt.c
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Diffstat (limited to 'drivers/hv/channel_mgmt.c')
-rw-r--r--drivers/hv/channel_mgmt.c58
1 files changed, 43 insertions, 15 deletions
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 38b682bab..b6c1211b4 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -597,27 +597,55 @@ static void init_vp_index(struct vmbus_channel *channel, u16 dev_type)
static void vmbus_wait_for_unload(void)
{
- int cpu = smp_processor_id();
- void *page_addr = hv_context.synic_message_page[cpu];
- struct hv_message *msg = (struct hv_message *)page_addr +
- VMBUS_MESSAGE_SINT;
+ int cpu;
+ void *page_addr;
+ struct hv_message *msg;
struct vmbus_channel_message_header *hdr;
- bool unloaded = false;
+ u32 message_type;
+ /*
+ * CHANNELMSG_UNLOAD_RESPONSE is always delivered to the CPU which was
+ * used for initial contact or to CPU0 depending on host version. When
+ * we're crashing on a different CPU let's hope that IRQ handler on
+ * the cpu which receives CHANNELMSG_UNLOAD_RESPONSE is still
+ * functional and vmbus_unload_response() will complete
+ * vmbus_connection.unload_event. If not, the last thing we can do is
+ * read message pages for all CPUs directly.
+ */
while (1) {
- if (READ_ONCE(msg->header.message_type) == HVMSG_NONE) {
- mdelay(10);
- continue;
- }
+ if (completion_done(&vmbus_connection.unload_event))
+ break;
- hdr = (struct vmbus_channel_message_header *)msg->u.payload;
- if (hdr->msgtype == CHANNELMSG_UNLOAD_RESPONSE)
- unloaded = true;
+ for_each_online_cpu(cpu) {
+ page_addr = hv_context.synic_message_page[cpu];
+ msg = (struct hv_message *)page_addr +
+ VMBUS_MESSAGE_SINT;
- vmbus_signal_eom(msg);
+ message_type = READ_ONCE(msg->header.message_type);
+ if (message_type == HVMSG_NONE)
+ continue;
- if (unloaded)
- break;
+ hdr = (struct vmbus_channel_message_header *)
+ msg->u.payload;
+
+ if (hdr->msgtype == CHANNELMSG_UNLOAD_RESPONSE)
+ complete(&vmbus_connection.unload_event);
+
+ vmbus_signal_eom(msg, message_type);
+ }
+
+ mdelay(10);
+ }
+
+ /*
+ * We're crashing and already got the UNLOAD_RESPONSE, cleanup all
+ * maybe-pending messages on all CPUs to be able to receive new
+ * messages after we reconnect.
+ */
+ for_each_online_cpu(cpu) {
+ page_addr = hv_context.synic_message_page[cpu];
+ msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
+ msg->header.message_type = HVMSG_NONE;
}
}