From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752024AbaC1LOa (ORCPT ); Fri, 28 Mar 2014 07:14:30 -0400 Received: from top.free-electrons.com ([176.31.233.9]:35389 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751965AbaC1LO0 (ORCPT ); Fri, 28 Mar 2014 07:14:26 -0400 From: Gregory CLEMENT To: Daniel Lezcano , "Rafael J. Wysocki" , linux-pm@vger.kernel.org, Jason Cooper , Andrew Lunn , Sebastian Hesselbarth , Gregory CLEMENT Cc: Thomas Petazzoni , Ezequiel Garcia , linux-arm-kernel@lists.infradead.org, Lior Amsalem , Tawfik Bayouk , Nadav Haklai , linux-kernel@vger.kernel.org Subject: [PATCH v6 06/11] ARM: mvebu: Low level function to disable HW coherency support Date: Fri, 28 Mar 2014 12:13:26 +0100 Message-Id: <1396005211-15573-7-git-send-email-gregory.clement@free-electrons.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1396005211-15573-1-git-send-email-gregory.clement@free-electrons.com> References: <1396005211-15573-1-git-send-email-gregory.clement@free-electrons.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When going to deep idle we need to disable the SoC snooping (aka hardware coherency support). Playing with the coherency fabric requires to use assembly code to be sure that the compiler doesn't reorder the instructions nor do wrong optimization. Signed-off-by: Gregory CLEMENT --- arch/arm/mach-mvebu/coherency_ll.S | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/arch/arm/mach-mvebu/coherency_ll.S b/arch/arm/mach-mvebu/coherency_ll.S index f2e2e8677c4b..6828f9f157b0 100644 --- a/arch/arm/mach-mvebu/coherency_ll.S +++ b/arch/arm/mach-mvebu/coherency_ll.S @@ -102,6 +102,26 @@ ENTRY(ll_enable_coherency) mov pc, lr ENDPROC(ll_enable_coherency) +ENTRY(ll_disable_coherency) + /* + * r0 being untouched in ll_get_coherency_base and + * ll_get_cpuid, we can use it to save lr modifing it with the + * following bl + */ + mov r0, lr + bl ll_get_coherency_base + bl ll_get_cpuid + mov lr, r0 + add r0, r1, #ARMADA_XP_CFB_CTL_REG_OFFSET +1: + ldrex r2, [r0] + bic r2, r2, r3 + strex r1, r2, [r0] + cmp r1, #0 + bne 1b + dsb + mov pc, lr +ENDPROC(ll_disable_coherency) .align 2 3: -- 1.8.1.2