From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailout4.samsung.com (mailout4.samsung.com [203.254.224.34]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 540481EB3D for ; Sat, 19 Jul 2025 07:18:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=203.254.224.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752909487; cv=none; b=RYLJbIMjQaNc4ncw2oc3kroO+cLbhQ3PrslIBs7ibkQjrVBYIrXcmSavYiBCkn9GSErG0/zxwdEhvCvg7axCHIvozH70uyLfmIibgGy2IEn/mKoJ/IHUhKlLA7twKFEzMYZCm42r++0BiGxSKktP74RN2n+ASCXKrThKGPUfMe0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752909487; c=relaxed/simple; bh=Ka8wbhGAtUXco/CEjaVgXQCExf5evykP9hZuaUlM4I8=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:In-Reply-To: Content-Type:References; b=VipgubWLMuppGW7HdeTd9fIevaOFNHfHh5TK7r0ptIKK0bn403jFCcEbgkG+0ZCMyfKxVkg4Fbrq/relgcFIrJdHilsDEvZTPQ3R5wB07r3Sdkmi0kQhIYF3BfqGHqyQTVnYfVqRnS8ZZkIO63QQZ+Q5Jyqkqjjer6JXQJAN8HM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=samsung.com; spf=pass smtp.mailfrom=samsung.com; dkim=pass (1024-bit key) header.d=samsung.com header.i=@samsung.com header.b=mOUQ3TaM; arc=none smtp.client-ip=203.254.224.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=samsung.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=samsung.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=samsung.com header.i=@samsung.com header.b="mOUQ3TaM" Received: from epcas5p2.samsung.com (unknown [182.195.41.40]) by mailout4.samsung.com (KnoxPortal) with ESMTP id 20250719071803epoutp04cb4e80757e953ef1510dcf92b77a6f94~TleNbnK0e1502115021epoutp04a for ; Sat, 19 Jul 2025 07:18:03 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout4.samsung.com 20250719071803epoutp04cb4e80757e953ef1510dcf92b77a6f94~TleNbnK0e1502115021epoutp04a DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=samsung.com; s=mail20170921; t=1752909483; bh=6DSre2VwzDo1w+Z2wYHJq9YH5OUDEQqT3Hf+FS+cC/U=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=mOUQ3TaM1Ta7zSty8Hl+zEy8g3GaM6hscv54/kdz7qMNDW915tIAngxwGTZJmykZ4 ykAWKTR0t1H22buN+mc9KaTO6Yplx1dJVTUhPe8Edtgt/t6gTSECFSjjuDOlactt2N 4jJ3r/jJHuQMgI9LWW1QofsLN7APa8et8MJLS930= Received: from epsnrtp01.localdomain (unknown [182.195.42.153]) by epcas5p4.samsung.com (KnoxPortal) with ESMTPS id 20250719071802epcas5p4c115f1ba86d86d744bef95836d949130~TleMgplGR0565305653epcas5p4s; Sat, 19 Jul 2025 07:18:02 +0000 (GMT) Received: from epcpadp2new (unknown [182.195.40.142]) by epsnrtp01.localdomain (Postfix) with ESMTP id 4bkdKk4qzyz6B9mB; Sat, 19 Jul 2025 07:18:02 +0000 (GMT) Received: from epsmtip2.samsung.com (unknown [182.195.34.31]) by epcas5p4.samsung.com (KnoxPortal) with ESMTPA id 20250718124523epcas5p41c5fbffd31f46267e94d73299d742851~TWStvua6C2913129131epcas5p4m; Fri, 18 Jul 2025 12:45:23 +0000 (GMT) Received: from test-PowerEdge-R740xd (unknown [107.99.41.79]) by epsmtip2.samsung.com (KnoxPortal) with ESMTPA id 20250718124520epsmtip293563894362cd4d77a9588e4a5e37f37~TWSrUpOEx1708417084epsmtip2u; Fri, 18 Jul 2025 12:45:20 +0000 (GMT) Date: Fri, 18 Jul 2025 18:15:15 +0530 From: Neeraj Kumar To: Dave Jiang Cc: dan.j.williams@intel.com, dave@stgolabs.net, jonathan.cameron@huawei.com, alison.schofield@intel.com, vishal.l.verma@intel.com, ira.weiny@intel.com, a.manzanares@samsung.com, nifan.cxl@gmail.com, anisa.su@samsung.com, vishak.g@samsung.com, krish.reddy@samsung.com, arun.george@samsung.com, alok.rathore@samsung.com, neeraj.kernel@gmail.com, linux-kernel@vger.kernel.org, linux-cxl@vger.kernel.org, nvdimm@lists.linux.dev, gost.dev@samsung.com, cpgs@samsung.com Subject: Re: [RFC PATCH 14/20] cxl/region: Add cxl pmem region creation routine for region persistency Message-ID: <1296674576.21752909482669.JavaMail.epsvc@epcpadp2new> Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: X-CMS-MailID: 20250718124523epcas5p41c5fbffd31f46267e94d73299d742851 X-Msg-Generator: CA Content-Type: multipart/mixed; boundary="----kMDsK0IEhKoUUkzyxABlnve5J-Otg2bCPR2yRM97vA1oUAWq=_23494_" X-Sendblock-Type: REQ_APPROVE CMS-TYPE: 105P X-CPGSPASS: Y X-Hop-Count: 3 X-CMS-RootMailID: 20250617124046epcas5p16a45d2afe3b41ca08994a5cca09bfb68 References: <20250617123944.78345-1-s.neeraj@samsung.com> <1691538257.61750165382463.JavaMail.epsvc@epcpadp2new> ------kMDsK0IEhKoUUkzyxABlnve5J-Otg2bCPR2yRM97vA1oUAWq=_23494_ Content-Type: text/plain; charset="utf-8"; format="flowed" Content-Disposition: inline On 10/07/25 08:59AM, Dave Jiang wrote: > > >On 6/17/25 5:39 AM, Neeraj Kumar wrote: >> Added exported cxl_create_pmem_region routine to create cxl pmem region >> from LSA parsed cxl region information. >> Inspirition for the function is taken from ndctl device attribute >> (_store) call. It allocates cxlr and fills information parsed from LSA >> and calls device_add(&cxlr->dev) to initiates further region creation >> porbes >> >> Signed-off-by: Neeraj Kumar >> --- >> drivers/cxl/core/port.c | 6 ++ >> drivers/cxl/core/region.c | 208 ++++++++++++++++++++++++++++++++++++++ >> drivers/cxl/cxl.h | 11 ++ >> 3 files changed, 225 insertions(+) >> >> diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c >> index bca668193c49..2452f7c15b2d 100644 >> --- a/drivers/cxl/core/port.c >> +++ b/drivers/cxl/core/port.c >> @@ -2150,6 +2150,12 @@ void cxl_bus_drain(void) >> } >> EXPORT_SYMBOL_NS_GPL(cxl_bus_drain, "CXL"); >> >> +void cxl_wq_flush(void) >> +{ >> + flush_workqueue(cxl_bus_wq); >> +} >> +EXPORT_SYMBOL_NS_GPL(cxl_wq_flush, "CXL"); >> + >> bool schedule_cxl_memdev_detach(struct cxl_memdev *cxlmd) >> { >> return queue_work(cxl_bus_wq, &cxlmd->detach_work); >> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c >> index b98b1ccffd1c..8990e3c3474d 100644 >> --- a/drivers/cxl/core/region.c >> +++ b/drivers/cxl/core/region.c >> @@ -2522,6 +2522,214 @@ static ssize_t create_ram_region_show(struct device *dev, >> return __create_region_show(to_cxl_root_decoder(dev), buf); >> } >> >> +static ssize_t update_region_size(struct cxl_region *cxlr, u64 val) > >Maybe call it resize_or_free_region_hpa()? > >Also rename 'val' to 'size' > Sure Dave, I will fix it next patch-set. >> +{ >> + int rc; >> + >> + rc = down_write_killable(&cxl_region_rwsem); >> + if (rc) >> + return rc; >> + >> + if (val) >> + rc = alloc_hpa(cxlr, val); >> + else >> + rc = free_hpa(cxlr); >> + up_write(&cxl_region_rwsem); >> + >> + if (rc) >> + return rc; >> + >> + return 0; >> +} > >Share common code with core/region.c:size_store(). Please use helper function and not duplicate code. > Sure, I will try to minimize duplicate code as much as possible in next patch-set. >> + >> +static ssize_t update_region_dpa_size(struct cxl_region *cxlr, > >resize_or_free_dpa() > Sure, I will fix it in next patch-set >> + struct cxl_decoder *cxld, >> + unsigned long long size) > >u64 size > Sure, I will fix it in next patch-set >> +{ >> + int rc; >> + struct cxl_endpoint_decoder *cxled = >> + to_cxl_endpoint_decoder(&cxld->dev); >> + >> + if (!IS_ALIGNED(size, SZ_256M)) >> + return -EINVAL; >> + >> + rc = cxl_dpa_free(cxled); >> + if (rc) >> + return rc; >> + >> + if (size == 0) >> + return 0; >> + >> + rc = cxl_dpa_alloc(cxled, size); >> + if (rc) >> + return rc; >> + >> + return 0; >> +} > >Share common code with core/port.c:dpa_size_store(). Please use helper function and not duplicate code. > Sure, I will try minimizing duplicate code as much as possible. >> + >> +static ssize_t update_region_dpa_mode(struct cxl_region *cxlr, >> + struct cxl_decoder *cxld) >> +{ >> + int rc; >> + struct cxl_endpoint_decoder *cxled = >> + to_cxl_endpoint_decoder(&cxld->dev); >> + >> + rc = cxl_dpa_set_mode(cxled, CXL_DECODER_PMEM); > >Don't think CXL_DECODER_PMEM exists any longer. It's CXL_PARTMODE_PMEM. Just beware there have been some changes while you are rebasing to the latest upstream code. > Thanks, I will rebase and fix it with latest change >> + if (rc) >> + return rc; >> + >> + return 0; >> +} >> + >> +static size_t attach_region_target(struct cxl_region *cxlr, >> + struct cxl_decoder *cxld, int pos) >> +{ >> + int rc; >> + struct cxl_endpoint_decoder *cxled = >> + to_cxl_endpoint_decoder(&cxld->dev); >> + >> + rc = attach_target(cxlr, cxled, pos, TASK_INTERRUPTIBLE); >> + >> + if (rc < 0) >> + return rc; >> + >> + return 0; >> +} >> + >> +static ssize_t commit_region(struct cxl_region *cxlr) >> +{ >> + struct cxl_region_params *p = &cxlr->params; >> + ssize_t rc; >> + >> + rc = down_write_killable(&cxl_region_rwsem); >> + if (rc) >> + return rc; >> + >> + /* Already in the requested state? */ >> + if (p->state >= CXL_CONFIG_COMMIT) >> + goto out; >> + >> + /* Not ready to commit? */ >> + if (p->state < CXL_CONFIG_ACTIVE) { >> + rc = -ENXIO; >> + goto out; >> + } >> + >> + /* >> + * Invalidate caches before region setup to drop any speculative >> + * consumption of this address space >> + */ >> + rc = cxl_region_invalidate_memregion(cxlr); >> + if (rc) >> + goto out; >> + >> + rc = cxl_region_decode_commit(cxlr); >> + if (rc == 0) >> + p->state = CXL_CONFIG_COMMIT; >> +out: >> + up_write(&cxl_region_rwsem); >> + if (rc) >> + return rc; >> + return 0; >> +} > >Sharing common code with core/region.c:commit_store()? > Sure, I will handle it in next patch-set >> + >> +static struct cxl_region * >> +devm_cxl_pmem_add_region(struct cxl_root_decoder *cxlrd, >> + struct cxl_decoder *cxld, >> + struct cxl_pmem_region_params *params, int id, >> + enum cxl_decoder_mode mode, enum cxl_decoder_type type) >> +{ >> + struct cxl_port *port; >> + struct cxl_region *cxlr; >> + struct cxl_region_params *p; >> + struct device *dev; >> + int rc; >> + >> + if (!cxlrd) >> + return ERR_PTR(-EINVAL); >> + >> + port = to_cxl_port(cxlrd->cxlsd.cxld.dev.parent); >> + >> + cxlr = cxl_region_alloc(cxlrd, id); >> + if (IS_ERR(cxlr)) >> + return cxlr; >> + cxlr->mode = mode; >> + cxlr->type = type; >> + >> + dev = &cxlr->dev; >> + rc = dev_set_name(dev, "region%d", id); >> + if (rc) >> + goto err; >> +> + p = &cxlr->params; >> + p->uuid = params->uuid; >> + p->interleave_ways = params->nlabel; >> + p->interleave_granularity = params->ig; >> + >> + /* Update region size */ >Not sure what value this comment adds Sure, I will remove these comments >> + if (update_region_size(cxlr, params->rawsize)) >> + goto err; >> + >> + /* Flush cxl wq */ >Can you explain here why a flush is needed? These steps of region creation is taken from how ndctl creates region using *_store(). I will re-look if its required here. >> + cxl_wq_flush(); >> + >> + /* Clear DPA Size */ >comment provides no value >> + if (update_region_dpa_size(cxlr, cxld, 0)) >> + goto err; >> + >> + /* Update DPA mode */ >same as above >> + if (update_region_dpa_mode(cxlr, cxld)) >> + goto err; >> + >> + /* Update DPA Size */ >same as above >> + if (update_region_dpa_size(cxlr, cxld, params->rawsize)) >> + goto err; >> + >> + /* Attach region targets */ >same as above >> + if (attach_region_target(cxlr, cxld, params->position)) >> + goto err; >> + >> + /* Commit Region */ >same as above Sure, I will remove unwanted comments >> + if (commit_region(cxlr)) >> + goto err; > >Can you please provide some verbose explanation as to what all these extra steps are doing for pmem versus devm_cxl_add_region() for dram? > These steps of region creation is taken from how ndctl creates region. Sure I will update the comments accordingly. >> + >> + rc = device_add(dev); >> + if (rc) >> + goto err; >> + >> + rc = devm_add_action_or_reset(port->uport_dev, unregister_region, cxlr); >> + if (rc) >> + return ERR_PTR(rc); >> + >> + dev_dbg(port->uport_dev, "%s: created %s\n", >> + dev_name(&cxlrd->cxlsd.cxld.dev), dev_name(dev)); >> + return cxlr; >> + >> +err: >> + put_device(dev); >> + return ERR_PTR(rc); >> +} >> + >> +struct cxl_region *cxl_create_pmem_region(struct cxl_root_decoder *cxlrd, >> + struct cxl_decoder *cxld, >> + struct cxl_pmem_region_params *params, int id) >> +{ >> + int rc; >> + >> + rc = memregion_alloc(GFP_KERNEL); >> + if (rc < 0) >> + return ERR_PTR(rc); >> + >> + if (atomic_cmpxchg(&cxlrd->region_id, id, rc) != id) { >> + memregion_free(rc); >> + return ERR_PTR(-EBUSY); >> + } >> + >> + return devm_cxl_pmem_add_region(cxlrd, cxld, params, id, >> + CXL_DECODER_PMEM, CXL_DECODER_HOSTONLYMEM); >> +} >> +EXPORT_SYMBOL_NS_GPL(cxl_create_pmem_region, "CXL"); > >Can __create_region() be modified to determine whether to create dram region or pmem? > >DJ Sure, I will refactor it accordingly Regards, Neeraj ------kMDsK0IEhKoUUkzyxABlnve5J-Otg2bCPR2yRM97vA1oUAWq=_23494_ Content-Type: text/plain; charset="utf-8" ------kMDsK0IEhKoUUkzyxABlnve5J-Otg2bCPR2yRM97vA1oUAWq=_23494_--