From patchwork Sat Oct 7 22:19:51 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuppuswamy Sathyanarayanan X-Patchwork-Id: 9991445 X-Patchwork-Delegate: andy.shevchenko@gmail.com Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 827DF60364 for ; Sat, 7 Oct 2017 22:22:02 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 75C1A28814 for ; Sat, 7 Oct 2017 22:22:02 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6A9DB28834; Sat, 7 Oct 2017 22:22:02 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E97CA28814 for ; Sat, 7 Oct 2017 22:22:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753290AbdJGWUX (ORCPT ); Sat, 7 Oct 2017 18:20:23 -0400 Received: from mga06.intel.com ([134.134.136.31]:9740 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753214AbdJGWUW (ORCPT ); Sat, 7 Oct 2017 18:20:22 -0400 Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga104.jf.intel.com with ESMTP; 07 Oct 2017 15:20:20 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.42,491,1500966000"; d="scan'208";a="157979747" Received: from skuppusw-desk.jf.intel.com ([10.7.198.92]) by orsmga005.jf.intel.com with ESMTP; 07 Oct 2017 15:20:20 -0700 From: sathyanarayanan.kuppuswamy@linux.intel.com To: a.zummo@towertech.it, x86@kernel.org, wim@iguana.be, mingo@redhat.com, alexandre.belloni@free-electrons.com, qipeng.zha@intel.com, hpa@zytor.com, dvhart@infradead.org, tglx@linutronix.de, lee.jones@linaro.org, andy@infradead.org, souvik.k.chakravarty@intel.com Cc: linux-rtc@vger.kernel.org, linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org, platform-driver-x86@vger.kernel.org, sathyaosid@gmail.com, Kuppuswamy Sathyanarayanan , Kuppuswamy Sathyanarayanan Subject: [RFC v5 1/8] platform/x86: intel_pmc_ipc: Use spin_lock to protect GCR updates Date: Sat, 7 Oct 2017 15:19:51 -0700 Message-Id: X-Mailer: git-send-email 2.7.4 In-Reply-To: References: Sender: platform-driver-x86-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: platform-driver-x86@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Kuppuswamy Sathyanarayanan Currently, update_no_reboot_bit() function implemented in this driver uses mutex_lock() to protect its register updates. But this function is called with in atomic context in iTCO_wdt_start() and iTCO_wdt_stop() functions in iTCO_wdt.c driver, which in turn causes "sleeping into atomic context" issue. This patch fixes this issue by replacing the mutex_lock() with spin_lock() to protect the GCR read/write/update APIs. Fixes: 9d855d4 ("platform/x86: intel_pmc_ipc: Fix iTCO_wdt GCS memory mapping failure") Signed-off-by: Kuppuswamy Sathyanarayanan --- drivers/platform/x86/intel_pmc_ipc.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) Changes since v4: * Fixed style issues in commit header. * Rebased this patch on top of Andy's review branch. diff --git a/drivers/platform/x86/intel_pmc_ipc.c b/drivers/platform/x86/intel_pmc_ipc.c index 751b121..e03fa314 100644 --- a/drivers/platform/x86/intel_pmc_ipc.c +++ b/drivers/platform/x86/intel_pmc_ipc.c @@ -33,6 +33,7 @@ #include #include #include +#include #include @@ -131,6 +132,7 @@ static struct intel_pmc_ipc_dev { /* gcr */ void __iomem *gcr_mem_base; bool has_gcr_regs; + spinlock_t gcr_lock; /* punit */ struct platform_device *punit_dev; @@ -225,17 +227,17 @@ int intel_pmc_gcr_read(u32 offset, u32 *data) { int ret; - mutex_lock(&ipclock); + spin_lock(&ipcdev.gcr_lock); ret = is_gcr_valid(offset); if (ret < 0) { - mutex_unlock(&ipclock); + spin_unlock(&ipcdev.gcr_lock); return ret; } *data = readl(ipcdev.gcr_mem_base + offset); - mutex_unlock(&ipclock); + spin_unlock(&ipcdev.gcr_lock); return 0; } @@ -255,17 +257,17 @@ int intel_pmc_gcr_write(u32 offset, u32 data) { int ret; - mutex_lock(&ipclock); + spin_lock(&ipcdev.gcr_lock); ret = is_gcr_valid(offset); if (ret < 0) { - mutex_unlock(&ipclock); + spin_unlock(&ipcdev.gcr_lock); return ret; } writel(data, ipcdev.gcr_mem_base + offset); - mutex_unlock(&ipclock); + spin_unlock(&ipcdev.gcr_lock); return 0; } @@ -287,7 +289,7 @@ int intel_pmc_gcr_update(u32 offset, u32 mask, u32 val) u32 new_val; int ret = 0; - mutex_lock(&ipclock); + spin_lock(&ipcdev.gcr_lock); ret = is_gcr_valid(offset); if (ret < 0) @@ -309,7 +311,7 @@ int intel_pmc_gcr_update(u32 offset, u32 mask, u32 val) } gcr_ipc_unlock: - mutex_unlock(&ipclock); + spin_unlock(&ipcdev.gcr_lock); return ret; } EXPORT_SYMBOL_GPL(intel_pmc_gcr_update); @@ -489,6 +491,8 @@ static int ipc_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) pmc->irq_mode = IPC_TRIGGER_MODE_IRQ; + spin_lock_init(&ipcdev.gcr_lock); + ret = pcim_enable_device(pdev); if (ret) return ret; @@ -903,6 +907,7 @@ static int ipc_plat_probe(struct platform_device *pdev) ipcdev.dev = &pdev->dev; ipcdev.irq_mode = IPC_TRIGGER_MODE_IRQ; init_completion(&ipcdev.cmd_complete); + spin_lock_init(&ipcdev.gcr_lock); ipcdev.irq = platform_get_irq(pdev, 0); if (ipcdev.irq < 0) {