From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752626AbbIGO1S (ORCPT ); Mon, 7 Sep 2015 10:27:18 -0400 Received: from mo4-p00-ob.smtp.rzone.de ([81.169.146.220]:9702 "EHLO mo4-p00-ob.smtp.rzone.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752406AbbIGO1O (ORCPT ); Mon, 7 Sep 2015 10:27:14 -0400 X-RZG-AUTH: :P2EQZWCpfu+qG7CngxMFH1J+yackYocTD1iAi8x+OWi/zfN1cLnDYU0tRQWJl4Hh2o4ySGRMBlDHYMqccew1oDb73L4= X-RZG-CLASS-ID: mo00 From: Olaf Hering To: kys@microsoft.com, gregkh@linuxfoundation.org, haiyangz@microsoft.com Cc: linux-kernel@vger.kernel.org, devel@linuxdriverproject.org, Olaf Hering Subject: [PATCH 1/4] hv: add helpers to handle hv_util device state Date: Mon, 7 Sep 2015 14:27:00 +0000 Message-Id: <1441636023-3704-2-git-send-email-olaf@aepfle.de> X-Mailer: git-send-email 2.5.1 In-Reply-To: <1441636023-3704-1-git-send-email-olaf@aepfle.de> References: <1441636023-3704-1-git-send-email-olaf@aepfle.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The callbacks in kvp, vss and fcopy code are called the main thread and also from interrupt context. If a state change is done by the main thread it is not immediately seen by the interrupt. As a result the state machine gets out of sync. Force propagation of state changes via get/set helpers with a memory barrier. Signed-off-by: Olaf Hering --- drivers/hv/hyperv_vmbus.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h index 3d70e36..6c03925 100644 --- a/drivers/hv/hyperv_vmbus.h +++ b/drivers/hv/hyperv_vmbus.h @@ -780,4 +780,16 @@ enum hvutil_device_state { HVUTIL_DEVICE_DYING, /* driver unload is in progress */ }; +static inline void hvutil_device_set_state(enum hvutil_device_state *p, enum hvutil_device_state s) +{ + *p = s; + wmb(); +} + +static inline enum hvutil_device_state hvutil_device_get_state(enum hvutil_device_state *p) +{ + rmb(); + return *p; +} + #endif /* _HYPERV_VMBUS_H */