From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELv+EcSOOEG9OERRpcC273dfOkujcesk+smnHS8yenphkA27f58fNzilgtC/c4p/oYeRxfTT ARC-Seal: i=1; a=rsa-sha256; t=1520936175; cv=none; d=google.com; s=arc-20160816; b=s2aruvN5sY6xLqWfLcNWSaWQzsm6JNSBzD2605ghHpeD000F1mynIuPWPciEW392Qd fUqG8kvb1IRLe/loU6f2GWMh5aoxUE5fDU+PWQc1+ebS6QHAHKl+ESv7n1jbAfS5e2Xl qGHLu3jqjJCf51poHiflAqiRSKexsb27cwzJX32Q/PuDNHLv6SGxaTD6tzA9S61/L+Cd O7ZqeLeCkmkUigD3rXgbr991Uo63kPUXewfA6vS4EJJDtEtmbBDOZwHOncobWhIq9j8y 2g+hQkcnCExBigNez7WqpNP34420JsqiUc7xCK841xM3H/AB3zgxyble6KtZVtQ+sb8S xFww== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:content-language:in-reply-to:mime-version :user-agent:date:message-id:organization:from:references:to:subject :cc:arc-authentication-results; bh=w+IFGq5Qq9VIkNT0zycQQUtuXJ4C4l9lVX2xPp6cBrw=; b=zXMz+1pAlbVhw5VvX/egOrFf92xFZvKJxW8H5ZjjIcj4yUOR/WmtG4s6IWexoUryFA X2TAxzIu2Nug7PLF+lmJTS89TrF4gZgig7H2HovOZzXqSuo8sDUHecyZq2dTa6NakuJa Mwsgj30jrkU0APwTXjo9xVPe+G4RWbkQmw/JsXvjDVDDwe8ED4zJ+VLyN9W/LSz6qVIq N2a+8mdg+qt4NQmsojmqZfqxTUAv0o2fj2o8qiT/SKTGtZUce4qEoQgltKyQaGv6io2Z Zjmha4o9SRuR1aE0trm6bTz665a2G6SLFfjl57pKksnLdSCMOnjLWK9s6WnjbDT04DLP iFow== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of sudeep.holla@arm.com designates 217.140.101.70 as permitted sender) smtp.mailfrom=sudeep.holla@arm.com Authentication-Results: mx.google.com; spf=pass (google.com: domain of sudeep.holla@arm.com designates 217.140.101.70 as permitted sender) smtp.mailfrom=sudeep.holla@arm.com Cc: Sudeep Holla , "gregkh@linuxfoundation.org" , "matt@codeblueprint.co.uk" , "hkallweit1@gmail.com" , "michal.simek@xilinx.com" , "robh+dt@kernel.org" , "mark.rutland@arm.com" , "ard.biesheuvel@linaro.org" , "mingo@kernel.org" , "keescook@chromium.org" , "dmitry.torokhov@gmail.com" , Rajan Vaja , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "devicetree@vger.kernel.org" Subject: Re: [PATCH v5 1/4] dt-bindings: firmware: Add bindings for ZynqMP firmware To: Jolly Shah References: <1519154467-2896-1-git-send-email-jollys@xilinx.com> <1519154467-2896-2-git-send-email-jollys@xilinx.com> <778329dd-76a7-0151-26d9-30e87e0c888d@arm.com> From: Sudeep Holla Organization: ARM Message-ID: <755770ba-d110-8b2e-3c1f-9b65686dc51f@arm.com> Date: Tue, 13 Mar 2018 10:16:03 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1592948931841332945?= X-GMAIL-MSGID: =?utf-8?q?1594817171084102195?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On 12/03/18 23:07, Jolly Shah wrote: > Hi Sudeep, >>>> Do you foresee using SMC/HVC for this firmware even on future platforms? >>>> If not, I suggest to keep the protocol part separate from the transport i.e. >>>> smc/hvc via ATF. It could be replaced with mailbox or some h/w >>>> mechanism in future ? >>>> >>> >>> We have PSCI and EEMI interfaces exposed to linux from ATF. PSCI is an >>> EEMI client. We do not have current plans to switch to mailbox as it >>> will require 2 communication channels to PMU as PSCI is through ATF. >>> >> >> OK, but I just saw some bindings that has mailbox interface, honestly it's getting >> too confusing with multiple series on the same thing floating and hence I >> requested to put it together as one series. > > Mailbox binding is used for power management driver. Mailbox is only > used for PMU->APU communication. APU->PMU communication is always > through EEMI firmware interface which is using SMC/HVC. > Ah OK, is it because there's no non-secure mailbox or to avoid races, all non-secure EEMI is channeled through SMC ? -- Regards, Sudeep