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=-13.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 D858FC433EF for ; Fri, 10 Sep 2021 19:19:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B3DBE611CC for ; Fri, 10 Sep 2021 19:19:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229546AbhIJTUx (ORCPT ); Fri, 10 Sep 2021 15:20:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38468 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232893AbhIJTUr (ORCPT ); Fri, 10 Sep 2021 15:20:47 -0400 Received: from mail-pg1-x532.google.com (mail-pg1-x532.google.com [IPv6:2607:f8b0:4864:20::532]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EC9ACC061574 for ; Fri, 10 Sep 2021 12:19:35 -0700 (PDT) Received: by mail-pg1-x532.google.com with SMTP id q68so2713601pga.9 for ; Fri, 10 Sep 2021 12:19:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=intel-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=2FFUPNmcpi0fbVrdhZiUCTe49bCRQ8pwPY+Ucyew4Q8=; b=wbBZOvk0r06K9c8DRoMFgJegj09Nf00q3H48X0oVV4IKoQ57gOfynrUBnfHyv5NXDy igCI1CbI3H7gmaQnMNSWusdHtT8P5+kABRs3uOAqrfYyvsF3gtsPvsviD55o+Yg0HOCB PvXUsshCmt+NticfDGNP+s6tKe4Dk/HSrcpJWfZxWUe2HgIoPNXRuparcNq/o9o7AQ4t maw8FipBR7elr7zU8EC5itrrPVvm6+sCyaVjOvPgCNbkUJSENu60CNQ3uVgQ57v30s5g PigT85/1IIaili4adryyGgVMNMViPGYy54sxbz0YXvHhkWJ6Irbe6e1ZZIsGkhgNKcUa cN1g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=2FFUPNmcpi0fbVrdhZiUCTe49bCRQ8pwPY+Ucyew4Q8=; b=H6sFzQs8I8Lv+CAzxVqdfDEYcNI0PT01P2QRnf/BbNyZZDjrx+eug10cYb31aHW9+z bf+u2m3IgYnVipVaPZDEczFEF0sNHCyA2Cmym6atOyctRAcrtcODxi+OrFwWIaXQDzE8 ANI1QRg3UItxiTKPPn97YSZMTG1ckpUS7YaMXWiFLakwkM7I+Y0vwWeq5HBxyN9cmW7g IXrFxPXhRG9eWzAchlyhCUDXBL0Q4XEUx2FwL6yZEuR5vNrvvnAqxwLToNcGDE3xnnD/ GJW7JXS6gET3h1wvY65Qmr1WRl7x7PyyScj3v0V7FXN56BS2kuqFqDeM7SxJfNdYsk7B syBg== X-Gm-Message-State: AOAM531KJDIoAHrFcMPepHISScYmmc82VkTVo2vxOJleN6Kj53N9mksi w2XOuftWLxJXZqcUEnXgocUco1q9cyDFVfZgjFwkiw== X-Google-Smtp-Source: ABdhPJwae/fIA3HfZ9N6remklOazWDQtrIk0HjH1y/Zp0rzqdWSPsfaPmWg+rC8B/lLo9Mm24SPRYgb5Hr4GnYZYEUU= X-Received: by 2002:a62:1b92:0:b0:3eb:3f92:724 with SMTP id b140-20020a621b92000000b003eb3f920724mr9496650pfb.3.1631301575421; Fri, 10 Sep 2021 12:19:35 -0700 (PDT) MIME-Version: 1.0 References: <20210902195017.2516472-1-ben.widawsky@intel.com> <20210902195017.2516472-5-ben.widawsky@intel.com> In-Reply-To: <20210902195017.2516472-5-ben.widawsky@intel.com> From: Dan Williams Date: Fri, 10 Sep 2021 12:19:24 -0700 Message-ID: Subject: Re: [PATCH 04/13] cxl: Introduce endpoint decoders To: Ben Widawsky Cc: linux-cxl@vger.kernel.org, Alison Schofield , Ira Weiny , Jonathan Cameron , Vishal Verma Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org On Thu, Sep 2, 2021 at 12:50 PM Ben Widawsky wrote: > > Endpoints have decoders too. It is useful to share the same > infrastructure from cxl_core. Endpoints do not have dports (downstream > targets), only the underlying physical medium. As a result, some special > casing is needed. > > There is no functional change introduced yet as endpoints don't actually > enumerate decoders yet. > > Signed-off-by: Ben Widawsky > --- > drivers/cxl/core/bus.c | 29 +++++++++++++++++++++++++---- > 1 file changed, 25 insertions(+), 4 deletions(-) > > diff --git a/drivers/cxl/core/bus.c b/drivers/cxl/core/bus.c > index 8d5061b0794d..6202ce5a5ac2 100644 > --- a/drivers/cxl/core/bus.c > +++ b/drivers/cxl/core/bus.c > @@ -175,6 +175,12 @@ static const struct attribute_group *cxl_decoder_switch_attribute_groups[] = { > NULL, > }; > > +static const struct attribute_group *cxl_decoder_endpoint_attribute_groups[] = { > + &cxl_decoder_base_attribute_group, > + &cxl_base_attribute_group, > + NULL, > +}; > + > static void cxl_decoder_release(struct device *dev) > { > struct cxl_decoder *cxld = to_cxl_decoder(dev); > @@ -184,6 +190,12 @@ static void cxl_decoder_release(struct device *dev) > kfree(cxld); > } > > +static const struct device_type cxl_decoder_endpoint_type = { > + .name = "cxl_decoder_endpoint", > + .release = cxl_decoder_release, > + .groups = cxl_decoder_endpoint_attribute_groups, > +}; > + > static const struct device_type cxl_decoder_switch_type = { > .name = "cxl_decoder_switch", > .release = cxl_decoder_release, > @@ -196,6 +208,11 @@ static const struct device_type cxl_decoder_root_type = { > .groups = cxl_decoder_root_attribute_groups, > }; > > +static bool is_endpoint_decoder(struct device *dev) > +{ > + return dev->type == &cxl_decoder_endpoint_type; > +} > + > bool is_root_decoder(struct device *dev) > { > return dev->type == &cxl_decoder_root_type; > @@ -472,7 +489,7 @@ struct cxl_decoder *cxl_decoder_alloc(struct cxl_port *port, int nr_targets) > struct device *dev; > int rc = 0; > > - if (nr_targets > CXL_DECODER_MAX_INTERLEAVE || nr_targets < 1) > + if (nr_targets > CXL_DECODER_MAX_INTERLEAVE) > return ERR_PTR(-EINVAL); > > cxld = kzalloc(struct_size(cxld, target, nr_targets), GFP_KERNEL); > @@ -491,8 +508,11 @@ struct cxl_decoder *cxl_decoder_alloc(struct cxl_port *port, int nr_targets) > dev->parent = &port->dev; > dev->bus = &cxl_bus_type; > > + /* Endpoints don't have a target list */ > + if (nr_targets == 0) > + dev->type = &cxl_decoder_endpoint_type; Do you also plan to introduce the concept of endpoint ports, and if yes should that come before this patch? That would seem to be more robust than, for example, allowing a switch port to carry an endpoint decoder object as this allows.