From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751926AbdBOQOo (ORCPT ); Wed, 15 Feb 2017 11:14:44 -0500 Received: from mail.kernel.org ([198.145.29.136]:51726 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751807AbdBOQOl (ORCPT ); Wed, 15 Feb 2017 11:14:41 -0500 From: Alan Tull To: Moritz Fischer , Jason Gunthorpe Cc: Alan Tull , linux-kernel@vger.kernel.org, linux-fpga@vger.kernel.org Subject: [RFC 5/8] fpga-mgr: separate getting/locking FPGA manager Date: Wed, 15 Feb 2017 10:14:18 -0600 Message-Id: <1487175261-7051-6-git-send-email-atull@kernel.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1487175261-7051-1-git-send-email-atull@kernel.org> References: <1487175261-7051-1-git-send-email-atull@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add fpga_mgr_lock/unlock functions that get a mutex for exclusive use. of_fpga_mgr_get, fpga_mgr_get, and fpga_mgr_put no longer lock the FPGA manager mutex. This makes it more straightforward to save a reference to a FPGA manager and only attempting to lock it when programming the FPGA. Signed-off-by: Alan Tull --- drivers/fpga/fpga-mgr.c | 44 +++++++++++++++++++++++++++++++------------ drivers/fpga/fpga-region.c | 13 +++++++++++-- include/linux/fpga/fpga-mgr.h | 3 +++ 3 files changed, 46 insertions(+), 14 deletions(-) diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c index b7c719a..3206a53 100644 --- a/drivers/fpga/fpga-mgr.c +++ b/drivers/fpga/fpga-mgr.c @@ -376,28 +376,19 @@ ATTRIBUTE_GROUPS(fpga_mgr); struct fpga_manager *__fpga_mgr_get(struct device *dev) { struct fpga_manager *mgr; - int ret = -ENODEV; mgr = to_fpga_manager(dev); if (!mgr) goto err_dev; - /* Get exclusive use of fpga manager */ - if (!mutex_trylock(&mgr->ref_mutex)) { - ret = -EBUSY; - goto err_dev; - } - if (!try_module_get(dev->parent->driver->owner)) - goto err_ll_mod; + goto err_dev; return mgr; -err_ll_mod: - mutex_unlock(&mgr->ref_mutex); err_dev: put_device(dev); - return ERR_PTR(ret); + return ERR_PTR(-ENODEV); } static int fpga_mgr_dev_match(struct device *dev, const void *data) @@ -457,12 +448,41 @@ EXPORT_SYMBOL_GPL(of_fpga_mgr_get); void fpga_mgr_put(struct fpga_manager *mgr) { module_put(mgr->dev.parent->driver->owner); - mutex_unlock(&mgr->ref_mutex); put_device(&mgr->dev); } EXPORT_SYMBOL_GPL(fpga_mgr_put); /** + * fpga_mgr_lock - Lock FPGA manager for exclusive use + * @mgr: fpga manager + * + * Given a pointer to FPGA Manager (from fpga_mgr_get() or + * of_fpga_mgr_put() attempt to get the mutex). + * + * Return: 0 for success or -EBUSY + */ +int fpga_mgr_lock(struct fpga_manager *mgr) +{ + if (!mutex_trylock(&mgr->ref_mutex)) { + dev_err(&mgr->dev, "FPGA manager is in use.\n"); + return -EBUSY; + } + + return 0; +} +EXPORT_SYMBOL_GPL(fpga_mgr_lock); + +/** + * fpga_mgr_unlock - Unlock FPGA manager + * @mgr: fpga manager + */ +void fpga_mgr_unlock(struct fpga_manager *mgr) +{ + mutex_unlock(&mgr->ref_mutex); +} +EXPORT_SYMBOL_GPL(fpga_mgr_unlock); + +/** * fpga_mgr_register - register a low level fpga manager driver * @dev: fpga manager device from pdev * @name: fpga manager name diff --git a/drivers/fpga/fpga-region.c b/drivers/fpga/fpga-region.c index 3a36417..a5d8112 100644 --- a/drivers/fpga/fpga-region.c +++ b/drivers/fpga/fpga-region.c @@ -142,7 +142,7 @@ static void fpga_region_put(struct fpga_region *region) } /** - * fpga_region_get_manager - get exclusive reference for FPGA manager + * fpga_region_get_manager - get reference for FPGA manager * @region: FPGA region * * Get FPGA Manager from "fpga-mgr" property or from ancestor region. @@ -265,10 +265,16 @@ static int fpga_region_program_fpga(struct fpga_region *region, return PTR_ERR(mgr); } + ret = fpga_mgr_lock(mgr); + if (ret) { + pr_err("FPGA manager is busy\n"); + goto err_put_mgr; + } + ret = fpga_region_get_bridges(region, reg_ovl); if (ret) { pr_err("failed to get fpga region bridges\n"); - goto err_put_mgr; + goto err_unlock_mgr; } ret = fpga_bridges_disable(®ion->bridge_list); @@ -289,6 +295,7 @@ static int fpga_region_program_fpga(struct fpga_region *region, goto err_put_br; } + fpga_mgr_unlock(mgr); fpga_mgr_put(mgr); fpga_region_put(region); @@ -296,6 +303,8 @@ static int fpga_region_program_fpga(struct fpga_region *region, err_put_br: fpga_bridges_put(®ion->bridge_list); +err_unlock_mgr: + fpga_mgr_unlock(mgr); err_put_mgr: fpga_mgr_put(mgr); fpga_region_put(region); diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h index 45df05a..ae970ca 100644 --- a/include/linux/fpga/fpga-mgr.h +++ b/include/linux/fpga/fpga-mgr.h @@ -149,6 +149,9 @@ int fpga_mgr_firmware_load(struct fpga_manager *mgr, int fpga_mgr_load(struct fpga_manager *mgr, struct fpga_image_info *info); +int fpga_mgr_lock(struct fpga_manager *mgr); +void fpga_mgr_unlock(struct fpga_manager *mgr); + struct fpga_manager *of_fpga_mgr_get(struct device_node *node); struct fpga_manager *fpga_mgr_get(struct device *dev); -- 2.7.4