From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2DCE9C433EF for ; Mon, 18 Oct 2021 17:32:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0E49960EB4 for ; Mon, 18 Oct 2021 17:32:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234100AbhJRReu (ORCPT ); Mon, 18 Oct 2021 13:34:50 -0400 Received: from foss.arm.com ([217.140.110.172]:40978 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233591AbhJRReq (ORCPT ); Mon, 18 Oct 2021 13:34:46 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 7DCF42F; Mon, 18 Oct 2021 10:32:34 -0700 (PDT) Received: from [10.1.196.28] (eglon.cambridge.arm.com [10.1.196.28]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0DCE93F694; Mon, 18 Oct 2021 10:32:33 -0700 (PDT) Subject: Re: [PATCH] firmware: arm_sdei: pass sdei_api_event_register right parameters To: =?UTF-8?B?5Lmx55+z?= Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20210910040117.98736-1-zhangliguang@linux.alibaba.com> <3fb354d1-bdc1-8aa2-aa90-4fd92e9a2e9a@arm.com> From: James Morse Message-ID: Date: Mon, 18 Oct 2021 18:32:33 +0100 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Liguang, On 11/10/2021 06:40, 乱石 wrote: > 在 2021/10/9 1:39, James Morse 写道: >> On 10/09/2021 05:01, Liguang Zhang wrote: >>> Function _local_event_enable is used for private sdei event >>> registeration called by sdei_event_register. We should pass >> (registration) >>> sdei_api_event_register right flag and mpidr parameters, otherwise atf >>> may trigger assert errors. >>> diff --git a/drivers/firmware/arm_sdei.c b/drivers/firmware/arm_sdei.c >>> index a7e762c352f9..0736752dadde 100644 >>> --- a/drivers/firmware/arm_sdei.c >>> +++ b/drivers/firmware/arm_sdei.c >>> @@ -558,14 +558,16 @@ static int sdei_api_event_register(u32 event_num, unsigned long >>> entry_point, >>>   static void _local_event_register(void *data) >>>   { >>>       int err; >>> +    u64 mpidr; >>>       struct sdei_registered_event *reg; >>>       struct sdei_crosscall_args *arg = data; >>>         WARN_ON(preemptible()); >>>   +    mpidr = read_cpuid_mpidr(); >>>       reg = per_cpu_ptr(arg->event->private_registered, smp_processor_id()); >>>       err = sdei_api_event_register(arg->event->event_num, sdei_entry_point, >>> -                      reg, 0, 0); >>> +                      reg, SDEI_EVENT_REGISTER_RM_PE, mpidr); >> Hmmm, this looks like a bug in TFA. >> >> 5.1.2.2 "Parameters" of DEN 0054B has: >> | Routing mode is valid only for a shared event. For a private event, the routing mode is >> | ignored. >> >> Worse, the mpidr field has: >> | Currently the format is defined only when the selected routing mode is RM_PE. > For a private event, we route SDEI_EVENT_REGISTER_RM_PE and mpidr parameters may be more > rationable. You are making this call from Linux? This isn't valid for private events. Private events are private to the CPU - they can only be reset, register and taken on that CPU. The specification for SDEI_EVENT_ROUTING_SET has this: | This call is used to change the routing information of a shared event. To borrow the GIC's terms: Private events are like PPI, Shared events are like SPI. >> Over in trusted firmware land: >> >> https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/tree/services/std_svc/sdei/sdei_main.c?h=v2.5#n361 >> >> >> | static int64_t sdei_event_register(int ev_num, >> |                 uint64_t ep, >> |                 uint64_t arg, >> |                 uint64_t flags, >> |                uint64_t mpidr) >> | { >> >> |    /* Private events always target the PE */ >> |    if (is_event_private(map)) >> |        flags = SDEI_REGF_RM_PE; >> >> It looks like this re-uses the 'caller specified the routing' code, but didn't update the >> mpidr. >> >> >> You mention TFA takes an assert failure, I assume that brings the machine down. >> (Presumably you don't have a CPU with an affinity of zero.) > Yes, that brings the machine down. In opensource ATF, CPU with an affinity of zero. > > The problem backaround: > > we use local secure arch timer as sdei watchdog timer Is that an SPI? If so, you should really be generating a shared event. > for hardlockup detection, in  os > panic ,we mask sdei event, then trigger the assert > if (se->reg_flags == SDEI_REGF_RM_PE) > > assert(se->affinity == my_mpidr); I'm not sure where this code in TFA is, but RM_PE for a private event is going to hit this on all but one CPU. You shouldn't be able to set RM_PE for a private event. I assume this is the TFA side of the problem from your colleague: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/11393 Does the problem occur with this TFA patch applied, and without any attempt to mess with the routing of per-cpu/private events? Thanks, James