From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nishanth Menon Subject: linux hardware spinlock framework for heterogeneous processor SOCs? Date: Wed, 11 Aug 2010 21:02:12 -0500 Message-ID: <4C635624.1090407@ti.com> References: <1279558221-14954-1-git-send-email-h-kanigeri2@ti.com> <1279558221-14954-4-git-send-email-h-kanigeri2@ti.com> <4C518AC0.6070809@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from arroyo.ext.ti.com ([192.94.94.40]:51499 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932932Ab0HLCCV (ORCPT ); Wed, 11 Aug 2010 22:02:21 -0400 In-Reply-To: Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: "Que, Simon" , LKML Cc: "Kanigeri, Hari" , Linux Omap , Tony Lindgren , "Shilimkar, Santosh" , "Cousson, Benoit" Changing subject, the original thread is at [1], looping in lkml for a wider audience for advice. Que, Simon had written, on 08/11/2010 05:03 PM, the following: >> just a curious question: >> >> Is there no h/w spinlock implementation for other architectures in >> linux? I mean the concept does not seem unique for a heterogenous >> processor environments now a days.. if it does exist, maybe we have two >> options: >> * extend standard spinlock architecture to handle h/w spinlocks as well >> * establish a new framework for h/w spinlocks.. >> > > Thank you for bringing that to my attention. I did a quick search and > haven't found any hwspinlock module elsewhere. But should there be > hwspinlocks over multiple architectures in the future, we can definitely > consider something like the two solutions that you suggested, so that > they can be used from platform-independent kernel code. However, right > now we can develop OMAP hwspinlock independently of that. I did glance through the kernel commit log, and nothing remotely seems to match up at least in my opinion (closest seemed to be [2] drivers/gpu/drm/ - but it did not seem relevant here). If this concept is unique to OMAP family alone, then I guess it makes sense to introduce SOC specific API library for usage. hoping for some suggestions to enlighten us. Ref: [1] http://marc.info/?t=127955774200003&r=1&w=2 [2] http://dri.sourceforge.net/doc/hardware_locking_low_level.html -- Regards, Nishanth Menon