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 DABB0C77B60 for ; Thu, 30 Mar 2023 18:55:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229895AbjC3Szw (ORCPT ); Thu, 30 Mar 2023 14:55:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58350 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231703AbjC3Szv (ORCPT ); Thu, 30 Mar 2023 14:55:51 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A74D6DE for ; Thu, 30 Mar 2023 11:55:49 -0700 (PDT) Received: from lhrpeml500005.china.huawei.com (unknown [172.18.147.206]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4PnXb55jg6z6J9Zd; Fri, 31 Mar 2023 02:52:01 +0800 (CST) Received: from localhost (10.195.247.161) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.21; Thu, 30 Mar 2023 19:55:46 +0100 Date: Thu, 30 Mar 2023 19:55:46 +0100 From: Jonathan Cameron To: CC: Dan Williams , Ira Weiny , Vishal Verma , "Ben Widawsky" , Dave Jiang , Subject: Re: [PATCH v5 03/12] cxl/memdev: Warn of poison inject or clear to a mapped region Message-ID: <20230330195546.00004774@Huawei.com> In-Reply-To: References: Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.195.247.161] X-ClientProxiedBy: lhrpeml500006.china.huawei.com (7.191.161.198) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org On Sun, 26 Mar 2023 22:03:09 -0700 alison.schofield@intel.com wrote: > From: Alison Schofield > > Inject and clear poison capabilities and intended for debug usage only. > In order to be useful in debug environments, the driver needs to allow > inject and clear operations on DPAs mapped in regions. > > dev_warn_once() when either operation occurs. > > Signed-off-by: Alison Schofield > --- > drivers/cxl/core/memdev.c | 59 +++++++++++++++++++++++++++++++++++++++ > 1 file changed, 59 insertions(+) > > diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c > index 0e39c3c3fb09..a83619c31f61 100644 > --- a/drivers/cxl/core/memdev.c > +++ b/drivers/cxl/core/memdev.c > @@ -213,6 +213,50 @@ ssize_t cxl_trigger_poison_list(struct device *dev, > } > EXPORT_SYMBOL_NS_GPL(cxl_trigger_poison_list, CXL); > > +struct cxl_dpa_to_region_context { > + struct cxl_region *cxlr; > + u64 dpa; > +}; > + > +static int __cxl_dpa_to_region(struct device *dev, void *arg) > +{ > + struct cxl_dpa_to_region_context *ctx = arg; > + struct cxl_endpoint_decoder *cxled; > + u64 dpa = ctx->dpa; > + > + if (!is_endpoint_decoder(dev)) > + return 0; > + > + cxled = to_cxl_endpoint_decoder(dev); > + if (!cxled->dpa_res || !resource_size(cxled->dpa_res)) > + return 0; > + > + if (dpa > cxled->dpa_res->end || dpa < cxled->dpa_res->start) > + return 0; > + > + dev_dbg(dev, "dpa:0x%llx mapped in region:%s\n", dpa, > + dev_name(&cxled->cxld.region->dev)); > + > + ctx->cxlr = cxled->cxld.region; > + If we have a match, little point in letting walk continue. return 1; Also, I "think" we just know that the association has been built. Injecting poison is probably still fine if the region / decoder hasn't yet been committed. Jonathan > + return 0; > +} > + > +static struct cxl_region *cxl_dpa_to_region(struct cxl_memdev *cxlmd, u64 dpa) > +{ > + struct cxl_dpa_to_region_context ctx; > + struct cxl_port *port; > + > + ctx = (struct cxl_dpa_to_region_context) { > + .dpa = dpa, > + }; > + port = dev_get_drvdata(&cxlmd->dev); > + if (port && is_cxl_endpoint(port) && port->commit_end != -1) > + device_for_each_child(&port->dev, &ctx, __cxl_dpa_to_region); > + > + return ctx.cxlr; > +} > + > static int cxl_validate_poison_dpa(struct cxl_memdev *cxlmd, u64 dpa) > { > struct cxl_dev_state *cxlds = cxlmd->cxlds; > @@ -242,6 +286,7 @@ int cxl_inject_poison(struct device *dev, u64 dpa) > struct cxl_memdev *cxlmd = to_cxl_memdev(dev); > struct cxl_mbox_inject_poison inject; > struct cxl_mbox_cmd mbox_cmd; > + struct cxl_region *cxlr; > int rc; > > if (!IS_ENABLED(CONFIG_DEBUG_FS)) > @@ -261,6 +306,13 @@ int cxl_inject_poison(struct device *dev, u64 dpa) > .payload_in = &inject, > }; > rc = cxl_internal_send_cmd(cxlmd->cxlds, &mbox_cmd); > + if (rc) > + goto out; > + > + cxlr = cxl_dpa_to_region(cxlmd, dpa); > + if (cxlr) > + dev_warn_once(dev, "poison inject dpa:0x%llx region: %s\n", > + dpa, dev_name(&cxlr->dev)); > out: > up_read(&cxl_dpa_rwsem); > > @@ -273,6 +325,7 @@ int cxl_clear_poison(struct device *dev, u64 dpa) > struct cxl_memdev *cxlmd = to_cxl_memdev(dev); > struct cxl_mbox_clear_poison clear; > struct cxl_mbox_cmd mbox_cmd; > + struct cxl_region *cxlr; > int rc; > > if (!IS_ENABLED(CONFIG_DEBUG_FS)) > @@ -303,7 +356,13 @@ int cxl_clear_poison(struct device *dev, u64 dpa) > }; > > rc = cxl_internal_send_cmd(cxlmd->cxlds, &mbox_cmd); > + if (rc) > + goto out; > > + cxlr = cxl_dpa_to_region(cxlmd, dpa); > + if (cxlr) > + dev_warn_once(dev, "poison clear dpa:0x%llx region: %s\n", > + dpa, dev_name(&cxlr->dev)); > out: > up_read(&cxl_dpa_rwsem); >