From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 309A61A0986 for ; Sat, 11 Oct 2014 02:58:37 +1100 (EST) Received: from e28smtp04.in.ibm.com (e28smtp04.in.ibm.com [122.248.162.4]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 82A851400AB for ; Sat, 11 Oct 2014 02:58:36 +1100 (EST) Received: from /spool/local by e28smtp04.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 10 Oct 2014 21:28:32 +0530 Received: from d28relay05.in.ibm.com (d28relay05.in.ibm.com [9.184.220.62]) by d28dlp01.in.ibm.com (Postfix) with ESMTP id A4A6AE0045 for ; Fri, 10 Oct 2014 21:31:23 +0530 (IST) Received: from d28av01.in.ibm.com (d28av01.in.ibm.com [9.184.220.63]) by d28relay05.in.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id s9AFwwM663504430 for ; Fri, 10 Oct 2014 21:28:59 +0530 Received: from d28av01.in.ibm.com (localhost [127.0.0.1]) by d28av01.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s9AFwRJG030605 for ; Fri, 10 Oct 2014 21:28:27 +0530 Subject: [PATCH v2] powerpc/powernv: Fallback to old HMI handling behavior for old firmware From: Mahesh J Salgaonkar To: Michael Ellerman , linuxppc-dev , Benjamin Herrenschmidt Date: Fri, 10 Oct 2014 21:28:26 +0530 Message-ID: <20141010155743.3855.36732.stgit@mars> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Cc: Paul Mackerras List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Mahesh Salgaonkar Recently we moved HMI handling into Linux kernel instead of taking HMI directly in OPAL. This new change is dependent on new OPAL call for HMI recovery which was introduced in newer firmware. While this new change works fine with latest OPAL firmware, we broke the HMI handling if we run newer kernel on old OPAL firmware that results in system hang. This patch fixes this issue by falling back to old HMI behavior on older OPAL firmware. This patch introduces a check for opal token OPAL_HANDLE_HMI to see if we are running on newer firmware or old firmware. On newer firmware this check would return OPAL_TOKEN_PRESENT, otherwise we are running on old firmware and fallback to old HMI behavior. Old firmware: POWER8 System Firmware Release as of today <= SV810_087 Action: Let OPAL handle HMIs Newer firmware: in development/yet to be released. Action: Let Linux host handle HMIs. This patch depends on opal check token patch posted at ppc-devel https://lists.ozlabs.org/pipermail/linuxppc-dev/2014-August/120224.html Signed-off-by: Mahesh Salgaonkar --- arch/powerpc/platforms/powernv/opal.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c index b44eec3..f172c15 100644 --- a/arch/powerpc/platforms/powernv/opal.c +++ b/arch/powerpc/platforms/powernv/opal.c @@ -194,6 +194,29 @@ static int __init opal_register_exception_handlers(void) * fwnmi area at 0x7000 to provide the glue space to OPAL */ glue = 0x7000; + + /* + * Check if we are running on newer firmware that exports + * OPAL_HANDLE_HMI token. If yes, then don't ask opal to patch + * HMI interrupt and we catch it directly in Linux kernel. + * + * For older firmware (i.e currently released POWER8 System Firmware + * as of today <= SV810_087), we fallback to old behavior and let OPAL + * to patch the HMI vector and handle it inside OPAL firmware. + * + * For newer firmware (in development/yet to be released) we will + * start catching/handling HMI directly in Linux kernel. + */ + if (!opal_check_token(OPAL_HANDLE_HMI)) { + /* We are on old firmware. fallback to old behavior. */ + pr_info("%s: Old firmware detected, let OPAL handle HMIs.\n", + "opal"); + opal_register_exception_handler( + OPAL_HYPERVISOR_MAINTENANCE_HANDLER, + 0, glue); + glue += 128; + } + opal_register_exception_handler(OPAL_SOFTPATCH_HANDLER, 0, glue); #endif