From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751571AbdJSAhn (ORCPT ); Wed, 18 Oct 2017 20:37:43 -0400 Received: from mga07.intel.com ([134.134.136.100]:48966 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750829AbdJSAhl (ORCPT ); Wed, 18 Oct 2017 20:37:41 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.43,398,1503385200"; d="scan'208";a="1026705391" From: sathyanarayanan.kuppuswamy@linux.intel.com To: dvhart@infradead.org, andy@infradead.org, qipeng.zha@intel.com Cc: linux-kernel@vger.kernel.org, platform-driver-x86@vger.kernel.org, sathyaosid@gmail.com, Kuppuswamy Sathyanarayanan , Andy Shevchenko Subject: [RFC v6-1 1/1] platform/x86: intel_pmc_ipc: Use spin_lock to protect GCR updates Date: Wed, 18 Oct 2017 17:37:14 -0700 Message-Id: <1508373434-115903-1-git-send-email-sathyanarayanan.kuppuswamy@linux.intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <0c13dfd2626df7b91b64dcc393e1d31e1a2c933f.1508368279.git.sathyanarayanan.kuppuswamy@linux.intel.com> References: <0c13dfd2626df7b91b64dcc393e1d31e1a2c933f.1508368279.git.sathyanarayanan.kuppuswamy@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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: 9d855d468dc6 ("platform/x86: intel_pmc_ipc: Fix iTCO_wdt GCS memory mapping failure") Signed-off-by: Kuppuswamy Sathyanarayanan Signed-off-by: Andy Shevchenko --- drivers/platform/x86/intel_pmc_ipc.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) Change since v6: * Fixed spelling error in signed-off-by email address. diff --git a/drivers/platform/x86/intel_pmc_ipc.c b/drivers/platform/x86/intel_pmc_ipc.c index bb792a5..af88221 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); @@ -487,6 +489,8 @@ static int ipc_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) ipcdev.dev = &pci_dev_get(pdev)->dev; ipcdev.irq_mode = IPC_TRIGGER_MODE_IRQ; + spin_lock_init(&ipcdev.gcr_lock); + ret = pci_enable_device(pdev); if (ret) return ret; @@ -924,6 +928,8 @@ static int ipc_plat_probe(struct platform_device *pdev) 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) { dev_err(&pdev->dev, "Failed to get irq\n"); -- 2.7.4