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 X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 38507C43460 for ; Wed, 14 Apr 2021 03:15:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0B57B613B1 for ; Wed, 14 Apr 2021 03:15:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230395AbhDNDPe (ORCPT ); Tue, 13 Apr 2021 23:15:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55892 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343720AbhDNDPd (ORCPT ); Tue, 13 Apr 2021 23:15:33 -0400 Received: from mail-ot1-x336.google.com (mail-ot1-x336.google.com [IPv6:2607:f8b0:4864:20::336]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4C91BC061574 for ; Tue, 13 Apr 2021 20:15:11 -0700 (PDT) Received: by mail-ot1-x336.google.com with SMTP id p6-20020a9d69460000b029028bb7c6ff64so2011785oto.10 for ; Tue, 13 Apr 2021 20:15:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=lWYNYk08w1Eqo11tDp7n2MyKlkaxOTUBjMHwWUDYMiU=; b=ybKZcbBXlGb+zPieCVgdhs+W/ZIPuFZYgO8jLu3+uu1SfGWdYkNWTsFu1VO/NYYxS9 VbKwCQ+hU6lCZjSOadkGrJnKZMspdWwEBZ/43/6v96dCeDGj4AjR/IBMP/+w7E5B45ok c3gVEVde/kscNze+iLaD1trJsjYmS4cP3mpScrOHJA5gf4NqwGrykbXMuJ7bhbATI8P2 u2VPWENfRe5Tex1PCFlypJEjC99+DgIJwlZ1VArVTnnv2fD7CMPzJFunxJaCBmqjZCFI Rlgl4NmRWrdaySA/H8jmUN7pKPjpIvXS9anTPVLXuDy1U2LPuXGpkA1Ci//u/e2iISPS 8ZzQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=lWYNYk08w1Eqo11tDp7n2MyKlkaxOTUBjMHwWUDYMiU=; b=RtTdLXbgu93ipuG7ijg1BOTshVV1OV5VT4666CCWdh+Gn+YD1aPkGofnEFoGawWvpn IU5W0kRRNR0NkFzP/PPYmHFCu0JJDeIcC9t5l2+olJMB58o6vwgIaMQg8O9NIqBNKcR3 oJJyJilfS6QK0xkFE07vaXsBlCYqqjghvS8fHsYo6rAo4SzlolGbUsD4aG84xTepTzhj aSf/nSUJ2FAAquG/imSn448qOALT341qwB7zu0soblnipBz10F8nTEBdxLAyv6yf3UV5 luniHblXmYK5/csQGmeKUbnhf7dsMOjEs8j18KA4oeH9c3+GhD4aob9IgFJRJeGi/mTd f8GA== X-Gm-Message-State: AOAM533rHImBocH/AzAOhtZuvJJSQ7XzYc61mKMlG9vS4tm3+HSuu2oB 2ujdOJh0AsTsCZuqSl/K/pZFPg== X-Google-Smtp-Source: ABdhPJzhuNpR60s28axQk88bCxDheLszIz7pnVj9A1oBNW6bNwfBRdsDc84DwlQ3JCGuQJQ9Kowyvg== X-Received: by 2002:a05:6830:3115:: with SMTP id b21mr30438984ots.318.1618370110582; Tue, 13 Apr 2021 20:15:10 -0700 (PDT) Received: from yoga (104-57-184-186.lightspeed.austtx.sbcglobal.net. [104.57.184.186]) by smtp.gmail.com with ESMTPSA id t14sm3872026otj.50.2021.04.13.20.15.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 13 Apr 2021 20:15:10 -0700 (PDT) Date: Tue, 13 Apr 2021 22:15:08 -0500 From: Bjorn Andersson To: Nikita Travkin Cc: Rob Herring , agross@kernel.org, linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] dt-bindings: soc: qcom: Add bindings for Qualcomm Memshare service Message-ID: <20210414031508.GZ1538589@yoga> References: <20210319172321.22248-1-nikitos.tr@gmail.com> <20210319172321.22248-2-nikitos.tr@gmail.com> <20210330144048.GA264685@robh.at.kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On Sat 10 Apr 03:05 CDT 2021, Nikita Travkin wrote: > Hi, sorry for a late reply but I couldn't answer earlier. > > 30.03.2021 19:40, Rob Herring ??????????: > > On Fri, Mar 19, 2021 at 10:23:20PM +0500, nikitos.tr@gmail.com wrote: > >> From: Nikita Travkin > >> > >> Add DT bindings for memshare: QMI service that allocates > >> memory per remote processor request. > >> > >> Signed-off-by: Nikita Travkin > >> --- > >> .../bindings/soc/qcom/qcom,memshare.yaml | 109 ++++++++++++++++++ > >> include/dt-bindings/soc/qcom,memshare.h | 10 ++ > >> 2 files changed, 119 insertions(+) > >> create mode 100644 Documentation/devicetree/bindings/soc/qcom/qcom,memshare.yaml > >> create mode 100644 include/dt-bindings/soc/qcom,memshare.h > >> > >> diff --git a/Documentation/devicetree/bindings/soc/qcom/qcom,memshare.yaml b/Documentation/devicetree/bindings/soc/qcom/qcom,memshare.yaml > >> new file mode 100644 > >> index 000000000000..ebdf128b066c > >> --- /dev/null > >> +++ b/Documentation/devicetree/bindings/soc/qcom/qcom,memshare.yaml > >> @@ -0,0 +1,109 @@ > >> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) > >> +%YAML 1.2 > >> +--- > >> +$id: "http://devicetree.org/schemas/soc/qcom/qcom,memshare.yaml#" > >> +$schema: "http://devicetree.org/meta-schemas/core.yaml#" > >> + > >> +title: Qualcomm QMI Shared Memory Service > > How many shared memory interfaces does Qcom have... > > > >> + > >> +description: | > >> + This driver provides a QMI service that allows remote processors (like modem) > >> + to request additional memory. It is used for applications like GPS in modem. > > If the memory region is defined in reserved-memory, how are you > > allocating additional memory? > > Initially remoteproc is loaded into it's own reserved-memory region > but qcom decided that they sometimes need more memory than that. > Memshare driver in msm8916 downstream tree seem to blindly allocate > DMA region for every request that it gets. Additionally for those > clients described in the DT, they do the DMA allocation on boot > time and never free the region. They call it "guaranteed" allocation. > > On msm8916 only one "guaranteed" client seem to be used so I decided > to implement it with reserved-memory node. On newer platforms they > seem to have more clients but I think that the driver can be easily > extended to support dynamic allocation if someone really needs it. > Is the "guaranteed" memory required to come from the reserved-memory part of memory, or could it simply be allocated on demand as well (or preallocated, but at a dynamic address)? If these allocations always came from a reserved-memory region, then adding a "qcom,memshare" compatible to the reserved-memory node itself seems like a reasonable approach. But if dma_alloc is sufficient, and there's cases where there's no "guaranteed" region, perhaps we should just describe this as part of the remoteproc node (i.e. essentially flipping the node/subnode in your current binding). E.g. can we get away with simply adding an optional qcom,memshare-node to the remoteproc binding and when that's present we make the Qualcomm remoteproc drivers spawn the memshare handler and listen for requests from that node? > I tried to explain that in the cover letter but I think I made some > mistake as I don't see it in the Patchwork. > > >> + > >> +maintainers: > >> + - Nikita Travkin > >> + > >> +properties: > >> + compatible: > >> + const: qcom,memshare > >> + > >> + qcom,legacy-client: > >> + $ref: /schemas/types.yaml#/definitions/phandle > >> + description: Phandle to a memshare client node used for legacy requests. > >> + > >> + "#address-cells": > >> + const: 1 > >> + > >> + "#size-cells": > >> + const: 0 > >> + > >> +patternProperties: > >> + "^.*@[0-9]+$": > >> + type: object > >> + > >> + properties: > >> + reg: > >> + description: Proc-ID for clients in this node. > > What's Proc-ID? > > The requests from the remote nodes contain client-id and proc-id > that are supposed to differentiate the clients. It's possible to > find the values in downstream DT or by observing what messages > are received by the memshare service (I left dev_dbg logging in > the driver for that reason) > > I think I should reword it to make this more apparent, maybe > "Proc-ID that clients in this node send."? > If this is a constant for each remote and we make this a child thing of remoteproc perhaps encode the number in the remoteproc nodes? (We still need something in DT to state that we want a memshare for a given platform/remoteproc) > > > >> + > >> + qcom,qrtr-node: > >> + $ref: /schemas/types.yaml#/definitions/uint32 > >> + description: Node from which the requests are expected. > >> + > >> + "#address-cells": > >> + const: 1 > >> + > >> + "#size-cells": > >> + const: 0 > >> + > >> + patternProperties: > >> + "^.*@[0-9]+$": > >> + type: object > >> + > >> + properties: > >> + reg: > >> + description: ID of this client. > > How does one determine the ID? > > As with proc-id, maybe reword to "ID that this client sends."? > > I will change those in v2, I still expect comments on the driver > itself, so I'll wait for that before submitting it with just a > couple lines changed. > > > > >> + > >> + memory-region: > >> + $ref: /schemas/types.yaml#/definitions/phandle > >> + description: | > >> + Reserved memory region that should be used for allocation. > >> + > >> + required: > >> + - reg > >> + > >> + required: > >> + - reg > >> + - qcom,qrtr-node > >> + > >> +required: > >> + - compatible > >> + > >> +additionalProperties: false > >> + > >> +examples: > >> + - | > >> + #include > >> + > >> + reserved-memory { > >> + > >> + #address-cells = <2>; > >> + #size-cells = <2>; > >> + > >> + gps_mem: gps@93c00000 { > >> + reg = <0x0 0x93c00000 0x0 0x200000>; > >> + no-map; > > We support 'compatible' in reserved-memory nodes, can you simplify the > > binding and put everything in here? > > If I understand this correctly, each reserved-memory node will > then load a new instance of memshare. Since the driver registers a > QMI service that handles multiple clients, there should be only one > instance. This you could work around in the driver implementation, to refcount a single implementation shared among all the instances. > Additionally, as I mentioned earlier, some clients may not > need reserved-memory at all > This on the other hand, makes me feel like we shouldn't go that route. Regards, Bjorn > >> + }; > >> + }; > >> + > >> + memshare { > >> + compatible = "qcom,memshare"; > >> + qcom,legacy-client = <&memshare_gps>; > >> + > >> + #address-cells = <1>; > >> + #size-cells = <0>; > >> + > >> + mpss@0 { > >> + reg = ; > >> + qcom,qrtr-node = <0>; > >> + > >> + #address-cells = <1>; > >> + #size-cells = <0>; > >> + > >> + memshare_gps: gps@0 { > >> + reg = <0>; > >> + memory-region = <&gps_mem>; > >> + }; > >> + }; > >> + }; > >> + > >> +... > >> diff --git a/include/dt-bindings/soc/qcom,memshare.h b/include/dt-bindings/soc/qcom,memshare.h > >> new file mode 100644 > >> index 000000000000..4cef1ef75d09 > >> --- /dev/null > >> +++ b/include/dt-bindings/soc/qcom,memshare.h > >> @@ -0,0 +1,10 @@ > >> +/* SPDX-License-Identifier: GPL-2.0 */ > >> + > >> +#ifndef __DT_QCOM_MEMSHARE_H__ > >> +#define __DT_QCOM_MEMSHARE_H__ > >> + > >> +#define MEMSHARE_PROC_MPSS_V01 0 > >> +#define MEMSHARE_PROC_ADSP_V01 1 > >> +#define MEMSHARE_PROC_WCNSS_V01 2 > >> + > >> +#endif /* __DT_QCOM_MEMSHARE_H__ */ > >> -- > >> 2.27.0 > >> >