From patchwork Wed Feb 5 02:31:11 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rajat Jain X-Patchwork-Id: 3584221 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Original-To: patchwork-linux-pci@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 862B6C02DC for ; Wed, 5 Feb 2014 02:31:43 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id A4040201B6 for ; Wed, 5 Feb 2014 02:31:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9CFDD200CC for ; Wed, 5 Feb 2014 02:31:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751234AbaBECbT (ORCPT ); Tue, 4 Feb 2014 21:31:19 -0500 Received: from mail-pd0-f177.google.com ([209.85.192.177]:61913 "EHLO mail-pd0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754759AbaBECbR (ORCPT ); Tue, 4 Feb 2014 21:31:17 -0500 Received: by mail-pd0-f177.google.com with SMTP id x10so8991542pdj.22 for ; Tue, 04 Feb 2014 18:31:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:cc:subject :content-type:content-transfer-encoding; bh=0h8tUKMNrj+mghFW2uTgqB0YcdSos4cWkyd47eY4/MI=; b=rGBOWPFSHOZGvIcy2OUkFMLF9166uS9+EwrGCahDxV2m4Mege50P321av62tpL49Nk UdW7jfwPcxL3t+cCk0YS4/kndVTzviyegSJCW6T9COsy26V7WRLH+/SqvAHdXQSNqe4w GcV/0QMa0wCgudFb0FzbTmcOu6RQoPWBngz2Hi1UmLgZfTxF9akvX4z7COwCOPJuC2a0 /2FstvrFc5rmUYUom4/Eg5XuodTgLE84FVdVECTfjBM2rXwtywUDOmkvNOCqYTu+NVpM n2xIdnRYtIV8qq22ku3EKf5q9g93oCu9fbbJEgIOnqGeVQR7Q3FdKDirso/CA4j8aEvF N6iw== X-Received: by 10.66.142.107 with SMTP id rv11mr48152257pab.17.1391567476218; Tue, 04 Feb 2014 18:31:16 -0800 (PST) Received: from [192.168.211.137] ([66.129.239.13]) by mx.google.com with ESMTPSA id iu7sm70848698pbc.45.2014.02.04.18.31.12 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 04 Feb 2014 18:31:15 -0800 (PST) Message-ID: <52F1A26F.3020105@gmail.com> Date: Tue, 04 Feb 2014 18:31:11 -0800 From: Rajat Jain User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130803 Thunderbird/17.0.8 MIME-Version: 1.0 To: Bjorn Helgaas , "Rafael J. Wysocki" , Kenji Kaneshige , Alex Williamson , Yijing Wang , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Yinghai Lu CC: Guenter Roeck , Rajat Jain , Rajat Jain Subject: [PATCH v4 8/8] pciehp: Introduce hotplug_lock to serialize HP events Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Spam-Status: No, score=-7.4 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, T_DKIM_INVALID, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Today it is there is no protection around pciehp_enable_slot() and pciehp_disable_slot() to ensure that they complete before another hot-plug operation can be done on that particular slot. This patch introduces the slot->hotplug_lock to ensure that any hotplug operations (add / remove) complete before another HP event can begin processing on that particular slot. Signed-off-by: Rajat Jain Signed-off-by: Rajat Jain Signed-off-by: Guenter Roeck --- drivers/pci/hotplug/pciehp.h | 1 + drivers/pci/hotplug/pciehp_core.c | 7 ++++++- drivers/pci/hotplug/pciehp_ctrl.c | 14 +++++++++++++- drivers/pci/hotplug/pciehp_hpc.c | 1 + 4 files changed, 21 insertions(+), 2 deletions(-) diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h index d8d0336..8a66866 100644 --- a/drivers/pci/hotplug/pciehp.h +++ b/drivers/pci/hotplug/pciehp.h @@ -76,6 +76,7 @@ struct slot { struct hotplug_slot *hotplug_slot; struct delayed_work work; /* work for button event */ struct mutex lock; + struct mutex hotplug_lock; struct workqueue_struct *wq; }; diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c index 53b58de..23b4bde 100644 --- a/drivers/pci/hotplug/pciehp_core.c +++ b/drivers/pci/hotplug/pciehp_core.c @@ -283,8 +283,11 @@ static int pciehp_probe(struct pcie_device *dev) slot = ctrl->slot; pciehp_get_adapter_status(slot, &occupied); pciehp_get_power_status(slot, &poweron); - if (occupied && pciehp_force) + if (occupied && pciehp_force) { + mutex_lock(&slot->hotplug_lock); pciehp_enable_slot(slot); + mutex_unlock(&slot->hotplug_lock); + } /* If empty slot's power status is on, turn power off */ if (!occupied && poweron && POWER_CTRL(ctrl)) pciehp_power_off_slot(slot); @@ -328,10 +331,12 @@ static int pciehp_resume (struct pcie_device *dev) /* Check if slot is occupied */ pciehp_get_adapter_status(slot, &status); + mutex_lock(&slot->hotplug_lock); if (status) pciehp_enable_slot(slot); else pciehp_disable_slot(slot); + mutex_unlock(&slot->hotplug_lock); return 0; } #endif /* PM */ diff --git a/drivers/pci/hotplug/pciehp_ctrl.c b/drivers/pci/hotplug/pciehp_ctrl.c index 3e40ec0..1f2716c 100644 --- a/drivers/pci/hotplug/pciehp_ctrl.c +++ b/drivers/pci/hotplug/pciehp_ctrl.c @@ -293,6 +293,7 @@ static void pciehp_power_thread(struct work_struct *work) struct power_work_info *info = container_of(work, struct power_work_info, work); struct slot *p_slot = info->p_slot; + int ret; switch (info->req) { case DISABLE_REQ: @@ -300,7 +301,9 @@ static void pciehp_power_thread(struct work_struct *work) "Disabling domain:bus:device=%04x:%02x:00\n", pci_domain_nr(p_slot->ctrl->pcie->port->subordinate), p_slot->ctrl->pcie->port->subordinate->number); + mutex_lock(&p_slot->hotplug_lock); pciehp_disable_slot(p_slot); + mutex_unlock(&p_slot->hotplug_lock); mutex_lock(&p_slot->lock); p_slot->state = STATIC_STATE; mutex_unlock(&p_slot->lock); @@ -310,8 +313,10 @@ static void pciehp_power_thread(struct work_struct *work) "Enabling domain:bus:device=%04x:%02x:00\n", pci_domain_nr(p_slot->ctrl->pcie->port->subordinate), p_slot->ctrl->pcie->port->subordinate->number); + mutex_lock(&p_slot->hotplug_lock); if (pciehp_enable_slot(p_slot)) pciehp_green_led_off(p_slot); + mutex_unlock(&p_slot->hotplug_lock); mutex_lock(&p_slot->lock); p_slot->state = STATIC_STATE; mutex_unlock(&p_slot->lock); @@ -546,6 +551,9 @@ static void interrupt_event_handler(struct work_struct *work) kfree(info); } +/* + * Note: This function must be called with slot->hotplug_lock held + */ int pciehp_enable_slot(struct slot *p_slot) { u8 getstatus = 0; @@ -584,7 +592,9 @@ int pciehp_enable_slot(struct slot *p_slot) return rc; } - +/* + * Note: This function must be called with slot->hotplug_lock held + */ int pciehp_disable_slot(struct slot *p_slot) { u8 getstatus = 0; @@ -617,7 +627,9 @@ int pciehp_sysfs_enable_slot(struct slot *p_slot) case STATIC_STATE: p_slot->state = POWERON_STATE; mutex_unlock(&p_slot->lock); + mutex_lock(&p_slot->hotplug_lock); retval = pciehp_enable_slot(p_slot); + mutex_unlock(&p_slot->hotplug_lock); mutex_lock(&p_slot->lock); p_slot->state = STATIC_STATE; break; diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index 6433e73..da4b020 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -686,6 +686,7 @@ static int pcie_init_slot(struct controller *ctrl) slot->ctrl = ctrl; mutex_init(&slot->lock); + mutex_init(&slot->hotplug_lock); INIT_DELAYED_WORK(&slot->work, pciehp_queue_pushbutton_work); ctrl->slot = slot; return 0;