From patchwork Wed Oct 7 11:31:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Zhao, Haifeng" X-Patchwork-Id: 11820449 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 483D613B2 for ; Wed, 7 Oct 2020 11:33:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3866F20789 for ; Wed, 7 Oct 2020 11:33:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727752AbgJGLdq (ORCPT ); Wed, 7 Oct 2020 07:33:46 -0400 Received: from mga06.intel.com ([134.134.136.31]:24765 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727702AbgJGLdn (ORCPT ); Wed, 7 Oct 2020 07:33:43 -0400 IronPort-SDR: iwoJxEYC2GoIyS7zSZpwYTWVrlX2M1LRd5Vp8f8JJ6hkE8n6KemI9c2LLQthZ92RHTRPSAtpmg GuHdyfl670mw== X-IronPort-AV: E=McAfee;i="6000,8403,9766"; a="226492572" X-IronPort-AV: E=Sophos;i="5.77,346,1596524400"; d="scan'208";a="226492572" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Oct 2020 04:33:42 -0700 IronPort-SDR: TDVHQKDcRDR+CN8aIlfPpgFZ1tN4/6zbHOxToBpn0t5VBslZjxbvBVMmMaUGsuCp84OYkPhY20 TFl81T0ky6lg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.77,346,1596524400"; d="scan'208";a="354862173" Received: from shskylake.sh.intel.com ([10.239.48.137]) by orsmga007.jf.intel.com with ESMTP; 07 Oct 2020 04:33:39 -0700 From: Ethan Zhao To: bhelgaas@google.com, oohall@gmail.com, ruscur@russell.cc, lukas@wunner.de, andriy.shevchenko@linux.intel.com, stuart.w.hayes@gmail.com, mr.nuke.me@gmail.com, mika.westerberg@linux.intel.com Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, ashok.raj@linux.intel.com, sathyanarayanan.kuppuswamy@intel.com, xerces.zhao@gmail.com, Ethan Zhao Subject: [PATCH v8 4/6] PCI/ERR: simplify function pci_dev_set_io_state() with if Date: Wed, 7 Oct 2020 07:31:56 -0400 Message-Id: <20201007113158.48933-5-haifeng.zhao@intel.com> X-Mailer: git-send-email 2.18.4 In-Reply-To: <20201007113158.48933-1-haifeng.zhao@intel.com> References: <20201007113158.48933-1-haifeng.zhao@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org No function change. Signed-off-by: Ethan Zhao --- Changes: v8: based on Bjorn's code and truth table, simplify the logic of function pci_dev_set_io_state(), no function change. drivers/pci/pci.h | 54 ++++++++++++++++++++--------------------------- 1 file changed, 23 insertions(+), 31 deletions(-) diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 455b32187abd..bceb3f108744 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -359,39 +359,31 @@ struct pci_sriov { static inline bool pci_dev_set_io_state(struct pci_dev *dev, pci_channel_state_t new) { - bool changed = false; - device_lock_assert(&dev->dev); - switch (new) { - case pci_channel_io_perm_failure: - switch (dev->error_state) { - case pci_channel_io_frozen: - case pci_channel_io_normal: - case pci_channel_io_perm_failure: - changed = true; - break; - } - break; - case pci_channel_io_frozen: - switch (dev->error_state) { - case pci_channel_io_frozen: - case pci_channel_io_normal: - changed = true; - break; - } - break; - case pci_channel_io_normal: - switch (dev->error_state) { - case pci_channel_io_frozen: - case pci_channel_io_normal: - changed = true; - break; - } - break; +/* + * Truth table: + * requested new state + * current ------------------------------------------ + * state normal frozen perm_failure + * ------------ + ------------- ------------- ------------ + * normal | normal frozen perm_failure + * frozen | normal frozen perm_failure + * perm_failure | perm_failure* perm_failure* perm_failure + */ + + /* Can always put a device in perm_failure state */ + if (new == pci_channel_io_perm_failure) { + dev->error_state = pci_channel_io_perm_failure; + return true; } - if (changed) - dev->error_state = new; - return changed; + + /* If already in perm_failure, can't set to normal or frozen */ + if (dev->error_state == pci_channel_io_perm_failure) + return false; + + /* Can always change normal to frozen or vice versa */ + dev->error_state = new; + return true; } static inline int pci_dev_set_disconnected(struct pci_dev *dev, void *unused)