From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760414AbcHaKsQ (ORCPT ); Wed, 31 Aug 2016 06:48:16 -0400 Received: from mailapp01.imgtec.com ([195.59.15.196]:8038 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759368AbcHaKo6 (ORCPT ); Wed, 31 Aug 2016 06:44:58 -0400 From: Matt Redfearn To: Ralf Baechle CC: , Matt Redfearn , , Paul Burton Subject: [PATCH 02/10] MIPS: CPC: Avoid lock when MIPS CM >= 3 is present Date: Wed, 31 Aug 2016 11:44:31 +0100 Message-ID: <1472640279-26593-3-git-send-email-matt.redfearn@imgtec.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1472640279-26593-1-git-send-email-matt.redfearn@imgtec.com> References: <1472640279-26593-1-git-send-email-matt.redfearn@imgtec.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.150.130.83] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org MIPS CM version 3 removed the CPC_CL_OTHER register and instead the CM_CL_OTHER register is used to redirect the CPC_OTHER region. As such, we should not write the unimplmented register and can avoid the spinlock as well. These lock functions should aleady be called within the context of a mips_cm_{lock,unlock}_other pair ensuring the correct CPC_OTHER region will be accessed. Signed-off-by: Matt Redfearn Reviewed-by: Paul Burton --- arch/mips/kernel/mips-cpc.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/arch/mips/kernel/mips-cpc.c b/arch/mips/kernel/mips-cpc.c index 0e337f55ac60..2a45867d3b4f 100644 --- a/arch/mips/kernel/mips-cpc.c +++ b/arch/mips/kernel/mips-cpc.c @@ -71,6 +71,11 @@ int mips_cpc_probe(void) void mips_cpc_lock_other(unsigned int core) { unsigned int curr_core; + + if (mips_cm_revision() >= CM_REV_CM3) + /* Systems with CM >= 3 lock the CPC via mips_cm_lock_other */ + return; + preempt_disable(); curr_core = current_cpu_data.core; spin_lock_irqsave(&per_cpu(cpc_core_lock, curr_core), @@ -86,7 +91,13 @@ void mips_cpc_lock_other(unsigned int core) void mips_cpc_unlock_other(void) { - unsigned int curr_core = current_cpu_data.core; + unsigned int curr_core; + + if (mips_cm_revision() >= CM_REV_CM3) + /* Systems with CM >= 3 lock the CPC via mips_cm_lock_other */ + return; + + curr_core = current_cpu_data.core; spin_unlock_irqrestore(&per_cpu(cpc_core_lock, curr_core), per_cpu(cpc_core_lock_flags, curr_core)); preempt_enable(); -- 2.7.4