From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=2607:f8b0:4864:20::129; helo=mail-it1-x129.google.com; envelope-from=ard.biesheuvel@linaro.org; receiver=edk2-devel@lists.01.org Received: from mail-it1-x129.google.com (mail-it1-x129.google.com [IPv6:2607:f8b0:4864:20::129]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 178DD211D56D9 for ; Tue, 5 Mar 2019 23:38:17 -0800 (PST) Received: by mail-it1-x129.google.com with SMTP id e24so8109743itl.1 for ; Tue, 05 Mar 2019 23:38:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=VvEfoZSs0KNetCP46buXwHBQ4MlTsWV8ZwGUqZznr1w=; b=MoaA811jB5NExeZAxZGHl5BQLv1ist2HDYg0CzIY9kUZi/6x2SIRd1F8/UcsDzb1yo XWNTVLeK+ggcD8oKDtIqQXYPRFqUn4Ex/zMNY0y3On2bieh8n5b6OHsYdLabrOgWq1eT mz7l+yd8vUgE4u9d8/6f8ht7LcqESyPD8cRbt4Gk65f4AckZT444+GoB+dr83ZlTQghc bHE2XXIzoMD0pV1YhA61pCJkK6nRGxFrZQxKlboH/ogh1K9A9LbJXp2/Mc2lNNBIrEiU Ma9gB2QSULu8m2wPe2ysOdeCHRj1B8nf5S9PAnVHDYoDGrSX9duvNeU7UpmqgWY0DAh3 2cOg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=VvEfoZSs0KNetCP46buXwHBQ4MlTsWV8ZwGUqZznr1w=; b=hmrBBCISzjF2cU5uN/IMTwCM0lfWqualeQtg2FoTIl29LqyLob1FpXdVP1yLTYJ+EL +BEsQp1DEoxAwnVTZVjoY57hk+vgYIAcM44fCSsUmtc8L14n06ZLZVmiXWQM2NVIR8LY IMzVsKHoycnaiD1NM8Nm1pyZw6N6ILdgKp+Ze7YuamUXsRuzGP15M6a6KN8MC609OZae l03i5vw3k+FQg3LWxQChau54MxiJhevNIHXV+5kdQ/M86zPx4e+kJfCxIrSv4aClUkVQ injxBE93M9iuQhUwcsHCV+VfW7rKGEAYoNMdwAdBhq29nFYRqx6yi1ob75Ud7vE9Ja1g tTOg== X-Gm-Message-State: APjAAAW5p4d3+AIWO2kRbbblUAn0F6aeXjAtj1eHTiENoVxCcTHSX67B zOjUJrHO9Ko093XYKH6xuHdw50aeh7Stby6teDtCOg== X-Google-Smtp-Source: APXvYqwzIKPuDuqISuppMdy5SlGnfCkkGt4iMCr5jK+C3G+KBPRYPG+tuEoITu4YQxY2QBrL51Nl0ZfB6z81xTMQHdU= X-Received: by 2002:a05:6638:2a1:: with SMTP id d1mr3478384jaq.2.1551857897050; Tue, 05 Mar 2019 23:38:17 -0800 (PST) MIME-Version: 1.0 References: <734D49CCEBEEF84792F5B80ED585239D5C060382@SHSMSX104.ccr.corp.intel.com> In-Reply-To: <734D49CCEBEEF84792F5B80ED585239D5C060382@SHSMSX104.ccr.corp.intel.com> From: Ard Biesheuvel Date: Wed, 6 Mar 2019 08:38:05 +0100 Message-ID: To: "Ni, Ray" Cc: "leif.lindholm@linaro.org" , "edk2-devel@lists.01.org" Subject: Re: Does ARM platform produce MP protocol? X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 06 Mar 2019 07:38:18 -0000 Content-Type: text/plain; charset="UTF-8" On Wed, 6 Mar 2019 at 06:44, Ni, Ray wrote: > > Ard, Leif, > I am a bit interested in how ARM platform supports the MP? > PI Spec defines below protocol but I failed to find a driver in ARM platform producing this protocol. > Or did I miss anything? > No you are right. We don't expose that on ARM, since UEFI only runs on a single core. Bringing up and taking down cores is done via a protocol called PSCI, which is implemented by firmware running at a higher privilege level. So while it would be possible to implement the MP protocol on top of PSCI, we haven't identified a use case for it yet. (The OS calls PSCI directly to boot the secondary cores) > typedef struct _EFI_MP_SERVICES_PROTOCOL { > EFI_MP_SERVICES_GET_NUMBER_OF_PROCESSORS GetNumberOfProcessors; > EFI_MP_SERVICES_GET_PROCESSOR_INFO GetProcessorInfo; > EFI_MP_SERVICES_STARTUP_ALL_APS StartupAllAPs; > EFI_MP_SERVICES_STARTUP_THIS_AP StartupThisAP; > EFI_MP_SERVICES_SWITCH_BSP SwitchBSP; > EFI_MP_SERVICES_ENABLEDISABLEAP EnableDisableAP; > EFI_MP_SERVICES_WHOAMI WhoAmI; > } EFI_MP_SERVICES_PROTOCOL; > > Thanks, > Ray