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 E999EC83F14 for ; Tue, 29 Aug 2023 14:50:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235497AbjH2Oty (ORCPT ); Tue, 29 Aug 2023 10:49:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37674 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230054AbjH2Otw (ORCPT ); Tue, 29 Aug 2023 10:49:52 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4F8A3194; Tue, 29 Aug 2023 07:49:49 -0700 (PDT) Received: from lhrpeml500005.china.huawei.com (unknown [172.18.147.200]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4RZqvx5ySzz6K63w; Tue, 29 Aug 2023 22:45:01 +0800 (CST) Received: from localhost (10.202.227.76) 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 15.1.2507.31; Tue, 29 Aug 2023 15:49:46 +0100 Date: Tue, 29 Aug 2023 15:49:45 +0100 From: Jonathan Cameron To: Ira Weiny CC: Dan Williams , Navneet Singh , Fan Ni , Davidlohr Bueso , Dave Jiang , Alison Schofield , Vishal Verma , , Subject: Re: [PATCH RFC v2 05/18] cxl/port: Add Dynamic Capacity mode support to endpoint decoders Message-ID: <20230829154945.00002870@Huawei.com> In-Reply-To: <20230604-dcd-type2-upstream-v2-5-f740c47e7916@intel.com> References: <20230604-dcd-type2-upstream-v2-0-f740c47e7916@intel.com> <20230604-dcd-type2-upstream-v2-5-f740c47e7916@intel.com> 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: [10.202.227.76] X-ClientProxiedBy: lhrpeml500002.china.huawei.com (7.191.160.78) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 28 Aug 2023 22:20:56 -0700 Ira Weiny wrote: > Endpoint decoders used to map Dynamic Capacity must be configured to > point to the correct Dynamic Capacity (DC) Region. The decoder mode > currently represents the partition the decoder points to such as ram or > pmem. > > Expand the mode to include DC Regions. > > Co-developed-by: Navneet Singh > Signed-off-by: Navneet Singh > Signed-off-by: Ira Weiny I'm reading this in a linear fashion for now (and ideally that should always make sense) so I don't currently see the reason for the loops in here. If they are needed for a future patch, add something to the description to indicate that. > > --- > Changes for v2: > [iweiny: split from region creation patch] > --- > Documentation/ABI/testing/sysfs-bus-cxl | 19 ++++++++++--------- > drivers/cxl/core/hdm.c | 24 ++++++++++++++++++++++++ > drivers/cxl/core/port.c | 16 ++++++++++++++++ > 3 files changed, 50 insertions(+), 9 deletions(-) > > diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl > index 6350dd82b9a9..2268ffcdb604 100644 > --- a/Documentation/ABI/testing/sysfs-bus-cxl > +++ b/Documentation/ABI/testing/sysfs-bus-cxl > @@ -257,22 +257,23 @@ Description: > > What: /sys/bus/cxl/devices/decoderX.Y/mode > Date: May, 2022 > -KernelVersion: v6.0 > +KernelVersion: v6.0, v6.6 (dcY) > Contact: linux-cxl@vger.kernel.org > Description: > (RW) When a CXL decoder is of devtype "cxl_decoder_endpoint" it > translates from a host physical address range, to a device local > address range. Device-local address ranges are further split > - into a 'ram' (volatile memory) range and 'pmem' (persistent > - memory) range. The 'mode' attribute emits one of 'ram', 'pmem', > - 'mixed', or 'none'. The 'mixed' indication is for error cases > - when a decoder straddles the volatile/persistent partition > - boundary, and 'none' indicates the decoder is not actively > - decoding, or no DPA allocation policy has been set. > + into a 'ram' (volatile memory) range, 'pmem' (persistent > + memory) range, or Dynamic Capacity (DC) range. The 'mode' > + attribute emits one of 'ram', 'pmem', 'dcY', 'mixed', or > + 'none'. The 'mixed' indication is for error cases when a > + decoder straddles the volatile/persistent partition boundary, > + and 'none' indicates the decoder is not actively decoding, or > + no DPA allocation policy has been set. > > 'mode' can be written, when the decoder is in the 'disabled' > - state, with either 'ram' or 'pmem' to set the boundaries for the > - next allocation. > + state, with 'ram', 'pmem', or 'dcY' to set the boundaries for > + the next allocation. > > > What: /sys/bus/cxl/devices/decoderX.Y/dpa_resource > diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c > index a254f79dd4e8..3f4af1f5fac8 100644 > --- a/drivers/cxl/core/hdm.c > +++ b/drivers/cxl/core/hdm.c > @@ -267,6 +267,19 @@ static void devm_cxl_dpa_release(struct cxl_endpoint_decoder *cxled) > __cxl_dpa_release(cxled); > } > > +static int dc_mode_to_region_index(enum cxl_decoder_mode mode) > +{ > + int index = 0; > + > + for (int i = CXL_DECODER_DC0; i <= CXL_DECODER_DC7; i++) { As you are relying on them being in order and adjacent for the loop, why is if (mode < CXL_DECODER_DC0 || mode > CXL_DECODER_DC7) return -EINVAL; return mode - CXL_DECODER_DC0; Not sufficient? > + if (mode == i) > + return index; > + index++; > + } > + > + return -EINVAL; > +} > + > static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled, > resource_size_t base, resource_size_t len, > resource_size_t skipped) > @@ -429,6 +442,7 @@ int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled, > switch (mode) { > case CXL_DECODER_RAM: > case CXL_DECODER_PMEM: > + case CXL_DECODER_DC0 ... CXL_DECODER_DC7: > break; > default: > dev_dbg(dev, "unsupported mode: %d\n", mode); > @@ -456,6 +470,16 @@ int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled, > goto out; > } > > + for (int i = CXL_DECODER_DC0; i <= CXL_DECODER_DC7; i++) { > + int index = dc_mode_to_region_index(i); > + > + if (mode == i && !resource_size(&cxlds->dc_res[index])) { Not obvious why we have the loop in this patch - perhaps it makes sense later. If this is to enable later changes, then good to say that in the patch description. otherwise, something like. int index; rc = dc_mode_to_region_index(i); if (rc < 0) goto out; index = rc; if (!resource_size(&cxlds->dc_res[index]) { .... > + dev_dbg(dev, "no available dynamic capacity\n"); > + rc = -ENXIO; > + goto out; > + } > + } > + > cxled->mode = mode; > rc = 0; > out: > diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c > index f58cf01f8d2c..ce4a66865db3 100644 > --- a/drivers/cxl/core/port.c > +++ b/drivers/cxl/core/port.c > @@ -197,6 +197,22 @@ static ssize_t mode_store(struct device *dev, struct device_attribute *attr, > mode = CXL_DECODER_PMEM; > else if (sysfs_streq(buf, "ram")) > mode = CXL_DECODER_RAM; > + else if (sysfs_streq(buf, "dc0")) > + mode = CXL_DECODER_DC0; > + else if (sysfs_streq(buf, "dc1")) > + mode = CXL_DECODER_DC1; > + else if (sysfs_streq(buf, "dc2")) > + mode = CXL_DECODER_DC2; > + else if (sysfs_streq(buf, "dc3")) > + mode = CXL_DECODER_DC3; > + else if (sysfs_streq(buf, "dc4")) > + mode = CXL_DECODER_DC4; > + else if (sysfs_streq(buf, "dc5")) > + mode = CXL_DECODER_DC5; > + else if (sysfs_streq(buf, "dc6")) > + mode = CXL_DECODER_DC6; > + else if (sysfs_streq(buf, "dc7")) > + mode = CXL_DECODER_DC7; > else > return -EINVAL; > >