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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 19E34EB8FA5 for ; Wed, 6 Sep 2023 12:26:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237608AbjIFM0U (ORCPT ); Wed, 6 Sep 2023 08:26:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38642 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232760AbjIFM0U (ORCPT ); Wed, 6 Sep 2023 08:26:20 -0400 Received: from mail-pg1-x52b.google.com (mail-pg1-x52b.google.com [IPv6:2607:f8b0:4864:20::52b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 635C71717 for ; Wed, 6 Sep 2023 05:26:16 -0700 (PDT) Received: by mail-pg1-x52b.google.com with SMTP id 41be03b00d2f7-564b6276941so2470594a12.3 for ; Wed, 06 Sep 2023 05:26:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1694003176; x=1694607976; darn=vger.kernel.org; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date:from:to :cc:subject:date:message-id:reply-to; bh=kjnnzDLUDo2+D27D03H2YWRaB12AVyK4xgoDBE0WK78=; b=ygKQwRjKCVD+dfLm+tbjGg/m8JA3TgLbpihCkjPju/ASPe+/AAtsmJgtTfN2xDnFaH rf9ZmF592F9sLZFZ4U1HFk5W00934PS7JqDSCp9FYht50eLhOI/nO02bcbYfK7e15UrE RpgAzOWDZKQXXLFNwwcc0xUDGb0J41md5yvpgiSiL3oe1Bie5I/kw8e18qjUMkQZrWE5 W1r0C5fddqUqLgdIIL7S6wfh31CnqbmXjy8bzNEWZHsJ884vrglbSouXYCPIBRcG2SmK gVI3HOdw1V1wCk9qaGDAk2sqw7C+eij4cOoMq8cvYO9ne/ovjY9nWMV3D192iSFPXiWL ZB7Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1694003176; x=1694607976; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=kjnnzDLUDo2+D27D03H2YWRaB12AVyK4xgoDBE0WK78=; b=L7NQf9IrWvcwJ4HvEPugXc6CsnDlavkWXqEDvPsWV5o6ksMZLDldhrze/TqCuqdulA puqKVIhrxvvSxRA56ltKkAxTFSrvseBFo3PlU++YdtnKkgkT/31xsbidlFdkkjeOYlR3 bJHpjSedtLVzSuex53vzft3dedo1p88JvUbPIamhzeOSZd+GAC0PiM09GhKz0RGmyi8T 8IwxpIeO6F4CH/ttuS6s5LpxlgoPD9Gi0t4FP3IK6B5jCLLGbvl5rQa619qfX95jUZ++ oGRLEH//nSznjbVtHrYYFFYyOlpfrxQ3s6BqnRC5ipmoQ+tSbYRC5j30Ot3tuAovJs5w eqRA== X-Gm-Message-State: AOJu0Yw5YgRxcQwucK3ThtR8hhz0r5RzlZvu5RKc01N8HvvVfoMT+9AM FvsWt75dPpbbZ4olaYCL9Snu X-Google-Smtp-Source: AGHT+IFRy+f9cPt6hImhbeLHiudZgHv2ne6+5hiV0JlI5JP4oipQdy+eixxMA2W/+788/8cEth4xNw== X-Received: by 2002:a17:90b:fc8:b0:26f:2c5a:bbb3 with SMTP id gd8-20020a17090b0fc800b0026f2c5abbb3mr14027269pjb.40.1694003175797; Wed, 06 Sep 2023 05:26:15 -0700 (PDT) Received: from thinkpad ([120.138.12.139]) by smtp.gmail.com with ESMTPSA id 25-20020a17090a199900b002693505391csm13493081pji.37.2023.09.06.05.26.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 06 Sep 2023 05:26:15 -0700 (PDT) Date: Wed, 6 Sep 2023 17:56:05 +0530 From: Manivannan Sadhasivam To: Frank Li Cc: tglx@linutronix.de, aisheng.dong@nxp.com, bhelgaas@google.com, devicetree@vger.kernel.org, festevam@gmail.com, imx@lists.linux.dev, jdmason@kudzu.us, kernel@pengutronix.de, kishon@ti.com, krzysztof.kozlowski+dt@linaro.org, kw@linux.com, linux-arm-kernel@lists.infradead.org, linux-imx@nxp.com, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, lorenzo.pieralisi@arm.com, lpieralisi@kernel.org, maz@kernel.org, ntb@lists.linux.dev, peng.fan@nxp.com, robh+dt@kernel.org, s.hauer@pengutronix.de, shawnguo@kernel.org Subject: Re: [PATCH 1/3] PCI: endpoint: Add RC-to-EP doorbell support using platform MSI controller Message-ID: <20230906122605.GB5930@thinkpad> References: <20230426203436.1277307-1-Frank.Li@nxp.com> <20230426203436.1277307-2-Frank.Li@nxp.com> <20230902045214.GA2913@thinkpad> <20230902045328.GB2913@thinkpad> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Wed, Sep 06, 2023 at 12:24:50AM -0400, Frank Li wrote: > On Sat, Sep 02, 2023 at 10:23:28AM +0530, Manivannan Sadhasivam wrote: > > On Sat, Sep 02, 2023 at 10:22:25AM +0530, Manivannan Sadhasivam wrote: > > > On Wed, Apr 26, 2023 at 04:34:34PM -0400, Frank Li wrote: > > > > This commit introduces a common method for sending messages from the Root Complex > > > > (RC) to the Endpoint (EP) by utilizing the platform MSI interrupt controller, > > > > such as ARM GIC, as an EP doorbell. Maps the memory assigned for the BAR region > > > > by the PCI host to the message address of the platform MSI interrupt controller > > > > in the PCI EP. As a result, when the PCI RC writes to the BAR region, it triggers > > > > an IRQ at the EP. This implementation serves as a common method for all endpoint > > > > function drivers. > > > > > > > > However, it currently supports only one EP physical function due to limitations > > > > in ARM MSI/IMS readiness. > > > > > > > > > > I've provided generic comments below, but I will do one more thorough review > > > after seeing epf-test driver patch. > > > > > > > Signed-off-by: Frank Li > > > > --- > > > > drivers/pci/endpoint/pci-epf-core.c | 109 ++++++++++++++++++++++++++++ > > > > include/linux/pci-epf.h | 16 ++++ > > > > 2 files changed, 125 insertions(+) > > > > > > > > diff --git a/drivers/pci/endpoint/pci-epf-core.c b/drivers/pci/endpoint/pci-epf-core.c > > > > index 355a6f56fcea..94ac82bf84c5 100644 > > > > --- a/drivers/pci/endpoint/pci-epf-core.c > > > > +++ b/drivers/pci/endpoint/pci-epf-core.c > > > > @@ -6,10 +6,12 @@ > > > > * Author: Kishon Vijay Abraham I > > > > */ > > > > > > > > +#include > > > > > > Why is this needed? > > > > > > > #include > > > > #include > > > > #include > > > > #include > > > > +#include > > > > > > > > #include > > > > #include > > > > @@ -300,6 +302,113 @@ void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar, > > > > } > > > > EXPORT_SYMBOL_GPL(pci_epf_alloc_space); > > > > > > > > +static enum irqreturn pci_epf_interrupt_handler(int irq, void *data) > > > > > > static irqreturn_t > > > > > > s/pci_epf_interrupt_handler/pci_epf_doorbell_handler > > > > > > > +{ > > > > + struct pci_epf *epf = data; > > > > + > > > > + if (epf->event_ops && epf->event_ops->doorbell) > > > > + epf->event_ops->doorbell(epf, irq - epf->virq_base); > > > > + > > > > + return IRQ_HANDLED; > > > > +} > > > > + > > > > +static void pci_epf_write_msi_msg(struct msi_desc *desc, struct msi_msg *msg) > > > > +{ > > > > + struct pci_epc *epc = container_of(desc->dev, struct pci_epc, dev); > > > > + struct pci_epf *epf; > > > > + > > > > + /* Todo: Need check correct epf if multi epf supported */ > > > > + list_for_each_entry(epf, &epc->pci_epf, list) { > > > > + if (epf->msg && desc->msi_index < epf->num_msgs) > > > > + epf->msg[desc->msi_index] = *msg; > > > > + } > > > > +} > > > > + > > > > +int pci_epf_alloc_doorbell(struct pci_epf *epf, u16 num_msgs) > > > > +{ > > > > + struct irq_domain *domain; > > > > + struct pci_epc *epc; > > > > + struct device *dev; > > > > + int virq; > > > > + int ret; > > > > + int i; > > > > + > > > > + epc = epf->epc; > > > > + dev = &epc->dev; > > > > > > "epc_dev" to make it explicit > > All other place use 'dev', I think better keep the consistent. > > Frank > > > > > > > + > > > > + /* > > > > + * Current only support 1 function. > > > > > > What does this mean exactly? Even a single EPC can support multiple EPFs > > > > > > > Please ignore above comment. > > > > - Mani > > > > > > + * PCI IMS(interrupt message store) ARM support have not been > > > > + * ready yet. > > > > > > No need to mention platform irq controller name. > > what's means? > "PCI IMS ARM support" is not needed. Just say that only one EPF is supported. > > > > > > > + */ > > > > + if (epc->function_num_map != 1) > > > > > > Why can't you use, epf->func_no? > > > > > > > + return -EOPNOTSUPP; > > > > + > > > > + domain = dev_get_msi_domain(dev->parent); > > > > + if (!domain) > > > > + return -EOPNTSUPP; > > > > > > Newline > > > > > > > + dev_set_msi_domain(dev, domain); > > > > + > > > > + /* use parent of_node to get device id information */ > > > > + dev->of_node = dev->parent->of_node; > > > > + > > > > > > Why do you need of_node assignment inside EPF core? > > GIC need it to allocate a MSI irq to platform devices. > I think it may improve if IMS support. > Can't you assign it in the EPF driver itself? I do not want any OF reference in the EPF core since it has no OF support. - Mani > Frank > > > > > > > > + epf->msg = kcalloc(num_msgs, sizeof(struct msi_msg), GFP_KERNEL); > > > > + if (!epf->msg) > > > > + return -ENOMEM; > > > > + > > > > + epf->num_msgs = num_msgs; > > > > + > > > > > > Move this to the start of the function, after checks. > > > > > > > + ret = platform_msi_domain_alloc_irqs(dev, num_msgs, pci_epf_write_msi_msg); > > > > + if (ret) { > > > > + dev_err(dev, "Can't allocate MSI from system MSI controller\n"); > > > > > > "Failed to allocate MSI" > > > > > > > + goto err_mem; > > > > > > err_free_mem > > > > > > > + } > > > > + > > > > + for (i = 0; i < num_msgs; i++) { > > > > + virq = msi_get_virq(dev, i); > > > > + if (i == 0) > > > > + epf->virq_base = virq; > > > > + > > > > + ret = request_irq(virq, pci_epf_interrupt_handler, 0, > > > > + "pci-epf-doorbell", epf); > > > > > > IRQ name should have an index, otherwise all of them will have the same name. > > > > > > > + > > > > + if (ret) { > > > > + dev_err(dev, "Failure request doorbell IRQ\n"); > > > > > > "Failed to request doorbell" > > > > > > > + goto err_irq; > > > > > > err_free_irq > > > > > > > + } > > > > + } > > > > + > > > > + epf->num_msgs = num_msgs; > > > > > > Newline > > > > > > > + return ret; > > > > + > > > > +err_irq: > > > > + platform_msi_domain_free_irqs(dev); > > > > +err_mem: > > > > + kfree(epf->msg); > > > > + epf->msg = NULL; > > > > + epf->num_msgs = 0; > > > > + > > > > + return ret; > > > > +} > > > > +EXPORT_SYMBOL_GPL(pci_epf_alloc_doorbell); > > > > + > > > > +void pci_epf_free_doorbell(struct pci_epf *epf) > > > > +{ > > > > + struct pci_epc *epc; > > > > + int i; > > > > + > > > > + epc = epf->epc; > > > > + > > > > + for (i = 0; i < epf->num_msgs; i++) > > > > + free_irq(epf->virq_base + i, epf); > > > > + > > > > + platform_msi_domain_free_irqs(&epc->dev); > > > > + kfree(epf->msg); > > > > + epf->msg = NULL; > > > > + epf->num_msgs = 0; > > > > +} > > > > +EXPORT_SYMBOL_GPL(pci_epf_free_doorbell); > > > > + > > > > static void pci_epf_remove_cfs(struct pci_epf_driver *driver) > > > > { > > > > struct config_group *group, *tmp; > > > > diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h > > > > index b8441db2fa52..e187e3ee48d2 100644 > > > > --- a/include/linux/pci-epf.h > > > > +++ b/include/linux/pci-epf.h > > > > @@ -75,6 +75,7 @@ struct pci_epf_ops { > > > > struct pci_epc_event_ops { > > > > int (*core_init)(struct pci_epf *epf); > > > > int (*link_up)(struct pci_epf *epf); > > > > + int (*doorbell)(struct pci_epf *epf, int index); > > > > }; > > > > > > > > /** > > > > @@ -173,6 +174,9 @@ struct pci_epf { > > > > unsigned long vfunction_num_map; > > > > struct list_head pci_vepf; > > > > const struct pci_epc_event_ops *event_ops; > > > > + struct msi_msg *msg; > > > > + u16 num_msgs; > > > > + int virq_base; > > > > }; > > > > > > > > /** > > > > @@ -216,4 +220,16 @@ int pci_epf_bind(struct pci_epf *epf); > > > > void pci_epf_unbind(struct pci_epf *epf); > > > > int pci_epf_add_vepf(struct pci_epf *epf_pf, struct pci_epf *epf_vf); > > > > void pci_epf_remove_vepf(struct pci_epf *epf_pf, struct pci_epf *epf_vf); > > > > +int pci_epf_alloc_doorbell(struct pci_epf *epf, u16 nums); > > > > +void pci_epf_free_doorbell(struct pci_epf *epf); > > > > + > > > > +static inline struct msi_msg *epf_get_msg(struct pci_epf *epf) > > > > +{ > > > > + return epf->msg; > > > > +} > > > > + > > > > +static inline u16 epf_get_msg_num(struct pci_epf *epf) > > > > +{ > > > > + return epf->num_msgs; > > > > +} > > > > > > I don't see a need for these two functions as they are doing just dereferences. > > > > > > - Mani > > > > > > > #endif /* __LINUX_PCI_EPF_H */ > > > > -- > > > > 2.34.1 > > > > > > > > > > -- > > > மணிவண்ணன் சதாசிவம் > > > > -- > > மணிவண்ணன் சதாசிவம் -- மணிவண்ணன் சதாசிவம்