Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755801Ab3G2Vkj (ORCPT ); Mon, 29 Jul 2013 17:40:39 -0400 Received: from smtp.codeaurora.org ([198.145.11.231]:45741 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752633Ab3G2Vkh (ORCPT ); Mon, 29 Jul 2013 17:40:37 -0400 Date: Mon, 29 Jul 2013 14:40:35 -0700 From: Stephen Boyd To: Kumar Gala Cc: ohad@wizery.com, "linux-kernel@vger.kernel.org list" , linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, Jeffrey Hugo , Eric Holmberg Subject: Re: [PATCH] hwspinlock/msm: Add support for Qualcomm MSM HW Mutex block Message-ID: <20130729214035.GC8868@codeaurora.org> References: <1375128719-23642-1-git-send-email-galak@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5054 Lines: 163 On 07/29, Kumar Gala wrote: > > diff --git a/Documentation/devicetree/bindings/arm/msm/tcsr-mutex.txt b/Documentation/devicetree/bindings/arm/msm/tcsr-mutex.txt > > new file mode 100644 > > index 0000000..ddd6889 > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/arm/msm/tcsr-mutex.txt Maybe this should go under a new hwspinlock directory? > > @@ -0,0 +1,20 @@ > > +Qualcomm MSM Hardware Mutex Block: > > + > > +The hardware block provides mutexes utilized between different processors > > +on the SoC as part of the communication protocol used by these processors. > > + > > +Required properties: > > +- compatible: should be "qcom,tcsr-mutex" > > +- reg: Should contain registers location and length of mutex registers > > +- reg-names: > > + "mutex-base" - string to identify mutex registers > > +- qcom,num-locks: the number of locks/mutexes supported > > + > > +Example: > > + > > + qcom,tcsr-mutex@fd484000 { Maybe it should be hw-mutex@fd484000? > > + compatible = "qcom,tcsr-mutex"; > > + reg = <0xfd484000 0x1000>; > > + reg-names = "mutex-base"; > > + qcom,num-locks = <32>; > > + }; > > diff --git a/drivers/hwspinlock/msm_hwspinlock.c b/drivers/hwspinlock/msm_hwspinlock.c > > new file mode 100644 > > index 0000000..c7d80c5 > > --- /dev/null > > +++ b/drivers/hwspinlock/msm_hwspinlock.c > > @@ -0,0 +1,150 @@ > > +/* > > + * Copyright (c) 2013, The Linux Foundation. All rights reserved. > > + * > > + * This software is licensed under the terms of the GNU General Public > > + * License version 2, as published by the Free Software Foundation, and > > + * may be copied, distributed, and modified under those terms. > > + * > > + * This program is distributed in the hope that it will be useful, > > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > > + * GNU General Public License for more details. > > + */ > > + > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > + > > +#include please. > > + > > +#include "hwspinlock_internal.h" > > + > > +#define SPINLOCK_ID_APPS_PROC 1 > > +#define BASE_ID 0 > > + > > +static int msm_hwspinlock_trylock(struct hwspinlock *lock) > > +{ > > + void __iomem *lock_addr = lock->priv; > > + > > + writel_relaxed(SPINLOCK_ID_APPS_PROC, lock_addr); > > + smp_mb(); Are you sure you don't want mb() instead? What is this barrier for? Comment please. > > + return readl_relaxed(lock_addr) == SPINLOCK_ID_APPS_PROC; > > +} > > + > > +static void msm_hwspinlock_unlock(struct hwspinlock *lock) > > +{ > > + int lock_owner; > > + void __iomem *lock_addr = lock->priv; > > + > > + lock_owner = readl_relaxed(lock_addr); > > + if (lock_owner != SPINLOCK_ID_APPS_PROC) { > > + pr_err("%s: spinlock not owned by Apps (actual owner is %d)\n", > > + __func__, lock_owner); > > + } > > + > > + writel_relaxed(0, lock_addr); > > + smp_mb(); Same here. What is smp_mb() for? > > +} > > + > > +static const struct hwspinlock_ops msm_hwspinlock_ops = { > > + .trylock = msm_hwspinlock_trylock, > > + .unlock = msm_hwspinlock_unlock, > > +}; > > + > > +static struct of_device_id msm_hwspinlock_of_match[]; Why not just put the match table here then? Also, can it be const? > > +static int msm_hwspinlock_probe(struct platform_device *pdev) > > +{ > > + int ret, i, stride; > > + u32 num_locks; > > + struct hwspinlock_device *bank; > > + struct hwspinlock *hwlock; > > + struct resource *res; > > + void __iomem *iobase; > > + struct device_node *node = pdev->dev.of_node; > > + const struct of_device_id *match; > > + > > + match = of_match_device(msm_hwspinlock_of_match, &pdev->dev); > > + if (!match) > > + return -EINVAL; > > + > > + ret = of_property_read_u32(node, "qcom,num-locks", &num_locks); > > + if (ret || (num_locks == 0)) Drop useless (). > > + return -ENODEV; > > + > > + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mutex-base"); > > + iobase = devm_ioremap_resource(&pdev->dev, res); > > + if (IS_ERR(iobase)) > > + return PTR_ERR(iobase); > > + > > + bank = devm_kzalloc(&pdev->dev, > > + sizeof(*bank) + num_locks * sizeof(*hwlock), GFP_KERNEL); > > + if (!bank) > > + return -ENOMEM; > > + Style Nit: Maybe we could grow a local variable to get this to be one line. size_t array_size; array_size = num_lock * sizeof(*hwlock); bank = devm_kzalloc(&pdev->dev, sizeof(*bank) + array_size, GFP_KERNEL); -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/