Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756463AbbHZBZz (ORCPT ); Tue, 25 Aug 2015 21:25:55 -0400 Received: from mail-pa0-f41.google.com ([209.85.220.41]:34752 "EHLO mail-pa0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756412AbbHZBZx (ORCPT ); Tue, 25 Aug 2015 21:25:53 -0400 Message-ID: <1440552341.10987.53.camel@linaro.org> Subject: Re: [PATCH v1 3/3] arm64: dts: add Hi6220 mailbox node From: Haojian Zhuang To: Leo Yan Cc: Mark Rutland , Leif Lindholm , Rob Herring , Pawel Moll , Ian Campbell , Kumar Gala , Catalin Marinas , Will Deacon , Jassi Brar , Bintian Wang , Yiping Xu , Wei Xu , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "guodong.xu@linaro.org" , Jian Zhang , Zhenwei Wang , Haoju Mo , Dan Zhao , "kongfei@hisilicon.com" , Guangyue Zeng Date: Wed, 26 Aug 2015 09:25:41 +0800 In-Reply-To: <20150825160030.GA3774@leoy-linaro> References: <20150821184059.GB2000@svinekod> <20150824091845.GA28290@leoy-linaro> <20150824095144.GA7139@leverpostej> <1440411596.3517.12.camel@linaro.org> <20150824114903.GT10728@bivouac.eciton.net> <1440490427.10987.29.camel@linaro.org> <20150825094630.GU10728@bivouac.eciton.net> <1440497710.10987.42.camel@linaro.org> <20150825104256.GB13471@leverpostej> <1440510194.10987.52.camel@linaro.org> <20150825160030.GA3774@leoy-linaro> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.12.9-1+b1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3342 Lines: 98 On Wed, 2015-08-26 at 00:00 +0800, Leo Yan wrote: > On Tue, Aug 25, 2015 at 09:43:14PM +0800, Haojian Zhuang wrote: > > On Tue, 2015-08-25 at 11:42 +0100, Mark Rutland wrote: > > > > > Are you then going to hack GRUB, release a special HiKey version of > > > > > GRUB, not support any other versions, and still can your firmware > > > > > UEFI? > > > > > > > > I don't need to hack GRUB at all. > > > > > > Then it is working for you by pure chance alone. > > > > > > Please listen to the advice you are being given here; we're trying to > > > ensure that your platform functions (and continues to function) as best > > > it can. > > > > Since we discussed a lot on this, let's make a conclusion on it. > > > > 1. UEFI could append the reserved buffer in it's memory mapping. > > 2. These reserved buffer must be declared in DT, since we also need to > > support non-UEFI (uboot) at the same time. > > 3. Mailbox node should reference reserved buffer by phandle in DT. Then > > map the buffer as non-cacheable in driver. > > 4. These reserved buffer must use "no-map" property since it should be > > non-cacheable in driver. > > For more specific discussion for DTS, i list two options at here; > > - Option 1: just simply reserve memory regions through memory node, > and mailbox node will directly use the buffer through reg ranges; > > - Option 2: use reserved-memory and mailbox node will refer phandle > of reserved-memory; > > These two options both can work well with UEFI and Uboot, but option 1 > is more simple and straightforward; so i personally prefer it. But > look forwarding your guys' suggestion. > > Option 1: > > memory@0 { > device_type = "memory"; > reg = <0x00000000 0x00000000 0x00000000 0x05e00000>, > <0x00000000 0x05f00000 0x00000000 0x00eff000>, > <0x00000000 0x06e00000 0x00000000 0x0060f000>, > <0x00000000 0x07410000 0x00000000 0x38bf0000>; > }; > > [...] > > mailbox: mailbox@f7510000 { > #mbox-cells = <1>; > compatible = "hisilicon,hi6220-mbox"; > reg = <0x0 0xf7510000 0x0 0x1000>, /* IPC_S */ > <0x0 0x06dff800 0x0 0x0800>; /* Mailbox buffer */ > interrupts = ; > }; > > Option 2: > > memory@0 { > device_type = "memory"; > reg = <0x0 0x0 0x0 0x40000000>; > }; > > reserved-memory { > #address-cells = <2>; > #size-cells = <2>; > ranges; > > mcu_reserved: mcu_reserved@06dff000 { > no-map; > reg = <0x0 0x06dff000 0x0 0x00001000>, /* MCU mailbox buffer */ > <0x0 0x05e00000 0x0 0x00100000>, /* MCU firmware buffer */ > <0x0 0x0740f000 0x0 0x00001000>; /* MCU firmware section */ > }; > }; > > [...] > > mailbox: mailbox@f7510000 { > #mbox-cells = <1>; > compatible = "hisilicon,hi6220-mbox"; > reg = <0x0 0xf7510000 0x0 0x1000>; /* IPC_S */ > memory-region = <&mcu_reserved>; /* Mailbox buffer */ > interrupts = ; > }; I prefer the second one. From my view, memory node should only describe the hardware information of memory. Regards Haojian -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/