From patchwork Tue Jun 18 08:46:37 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Huang, Ying" X-Patchwork-Id: 13701980 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.17]) (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 5489C1B3F0E; Tue, 18 Jun 2024 08:46:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.17 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718700420; cv=none; b=uFVScr2V5NnZlbJ3IASGJZ2zbsARdsJQoSWXwAr0AzdXsN8YRiuE4rrRBudTain7ghOylrVrSRql14wF+miGfriRnOcjTPkzLzanTtF1I8M8lF+S5d593xv3c3DQniaYPVygY9TvGVV2Rjvm2tg3XB9pLcAkh6UP+rOIoRLPtDk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718700420; c=relaxed/simple; bh=dqGZ+zgb+03wm391muYNQpvHA9L8X0zYB+1+wZSU0I4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=eyNZBHiSMoVs7bsFNatbqt+Sl1kJyZs9qsWanPbD3BwaT7gqwJDTpSbZq/+ZRQwtoy3qhYKxqFg1ociKbh0fPgnu1lRIFdO+BjSUALErsVoi/Nzjerl2qaLdgzMb3+3W9qiNjHe2LRQiQI6GJ3rKBdsQN7Awzp6Vsz+yuz6bFCM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=PR5HZoU9; arc=none smtp.client-ip=192.198.163.17 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="PR5HZoU9" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1718700418; x=1750236418; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=dqGZ+zgb+03wm391muYNQpvHA9L8X0zYB+1+wZSU0I4=; b=PR5HZoU9rGmWUnf/1QcojLVVVS1PWc4dIAj8+AiYFS6D+q034Ec/43le eUiPLiInhhZMJJuwIudEG2LPn5jDKwbA/xMMtGv8H3BEIfycPWlKX48bm C3HoQkAwlRbOBPCO4jJBlilNo0Pr9enANjWMREfwi8xWF1vM/oVsEuwVA xKbzfqKUfkA58ljDVADYJ0n6XJAvEEIimWAmPwu7xemP0fPdgx7y9JY9M igOhrg7/U57Nrq0bHVqRhap6jcsmXwVGMrXtaPJxFuSint+m9M5J/pOfq 5GdCIAwFUHFPbi8YgfP/ahun5n5SJYFPsl3X1GDbvU0eDVCiDlmT6uljH A==; X-CSE-ConnectionGUID: 9Tn2R8eUR5mLcfg2wZAjZw== X-CSE-MsgGUID: XLBMazcVSMGSdt7c5bMWdQ== X-IronPort-AV: E=McAfee;i="6700,10204,11106"; a="15431596" X-IronPort-AV: E=Sophos;i="6.08,247,1712646000"; d="scan'208";a="15431596" Received: from orviesa001.jf.intel.com ([10.64.159.141]) by fmvoesa111.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Jun 2024 01:46:58 -0700 X-CSE-ConnectionGUID: rO6/Ob8RR/C9LFuqT5Y4Gg== X-CSE-MsgGUID: 7TUZPmcASqaacqk1t+AVbw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.08,247,1712646000"; d="scan'208";a="78933633" Received: from shilinmu-mobl.ccr.corp.intel.com (HELO yhuang6-mobl2.ccr.corp.intel.com) ([10.255.28.204]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Jun 2024 01:46:55 -0700 From: Huang Ying To: Dan Williams , Dave Jiang Cc: linux-cxl@vger.kernel.org, linux-kernel@vger.kernel.org, Huang Ying , Alison Schofield , Andrew Morton , Jonathan Cameron , Bharata B Rao , Alistair Popple , "Aneesh Kumar K . V" , Davidlohr Bueso , Vishal Verma , Ira Weiny Subject: [PATCH v3 1/3] cxl/region: Fix a race condition in memory hotplug notifier Date: Tue, 18 Jun 2024 16:46:37 +0800 Message-Id: <20240618084639.1419629-2-ying.huang@intel.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240618084639.1419629-1-ying.huang@intel.com> References: <20240618084639.1419629-1-ying.huang@intel.com> Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In the memory hotplug notifier function of the CXL region, cxl_region_perf_attrs_callback(), the node ID is obtained by checking the host address range of the region. However, the address range information is not available when the region is registered in devm_cxl_add_region(). Additionally, this information may be removed or added under the protection of cxl_region_rwsem during runtime. If the memory notifier is called for nodes other than that backed by the region, a race condition may occur, potentially leading to a NULL dereference or an invalid address range. The race condition is addressed by checking the availability of the address range information under the protection of cxl_region_rwsem. To enhance code readability and use guard(), the relevant code has been moved into a newly added function: cxl_region_nid(). Fixes: 067353a46d8c ("cxl/region: Add memory hotplug notifier for cxl region") Signed-off-by: "Huang, Ying" Cc: Dan Williams Cc: Alison Schofield Cc: Andrew Morton Cc: Jonathan Cameron Cc: Dave Jiang Cc: Bharata B Rao Cc: Alistair Popple Cc: Aneesh Kumar K.V Cc: Davidlohr Bueso Cc: Vishal Verma Cc: Ira Weiny Reviewed-by: Jonathan Cameron Reviewed-by: Davidlohr Bueso --- drivers/cxl/core/region.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 3c2b6144be23..51aeef2c012c 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -2304,14 +2304,25 @@ static bool cxl_region_update_coordinates(struct cxl_region *cxlr, int nid) return true; } +static int cxl_region_nid(struct cxl_region *cxlr) +{ + struct cxl_region_params *p = &cxlr->params; + struct cxl_endpoint_decoder *cxled; + struct cxl_decoder *cxld; + + guard(rwsem_read)(&cxl_region_rwsem); + cxled = p->targets[0]; + if (!cxled) + return NUMA_NO_NODE; + cxld = &cxled->cxld; + return phys_to_target_node(cxld->hpa_range.start); +} + static int cxl_region_perf_attrs_callback(struct notifier_block *nb, unsigned long action, void *arg) { struct cxl_region *cxlr = container_of(nb, struct cxl_region, memory_notifier); - struct cxl_region_params *p = &cxlr->params; - struct cxl_endpoint_decoder *cxled = p->targets[0]; - struct cxl_decoder *cxld = &cxled->cxld; struct memory_notify *mnb = arg; int nid = mnb->status_change_nid; int region_nid; @@ -2319,7 +2330,7 @@ static int cxl_region_perf_attrs_callback(struct notifier_block *nb, if (nid == NUMA_NO_NODE || action != MEM_ONLINE) return NOTIFY_DONE; - region_nid = phys_to_target_node(cxld->hpa_range.start); + region_nid = cxl_region_nid(cxlr); if (nid != region_nid) return NOTIFY_DONE; From patchwork Tue Jun 18 08:46:38 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Huang, Ying" X-Patchwork-Id: 13701981 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.17]) (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 D89E81B3F35; 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a="15431613" X-IronPort-AV: E=Sophos;i="6.08,247,1712646000"; d="scan'208";a="15431613" Received: from orviesa001.jf.intel.com ([10.64.159.141]) by fmvoesa111.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Jun 2024 01:47:02 -0700 X-CSE-ConnectionGUID: Gp/1WNAaQHuyaMoTwLIalw== X-CSE-MsgGUID: xDS04ZgLRruFXWzIg4mulQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.08,247,1712646000"; d="scan'208";a="78933646" Received: from shilinmu-mobl.ccr.corp.intel.com (HELO yhuang6-mobl2.ccr.corp.intel.com) ([10.255.28.204]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Jun 2024 01:46:58 -0700 From: Huang Ying To: Dan Williams , Dave Jiang Cc: linux-cxl@vger.kernel.org, linux-kernel@vger.kernel.org, Huang Ying , Alison Schofield , Andrew Morton , Jonathan Cameron , Bharata B Rao , Alistair Popple , "Aneesh Kumar K . V" , Davidlohr Bueso , Vishal Verma , Ira Weiny Subject: [PATCH v3 2/3] cxl/region: Support to calculate memory tier abstract distance Date: Tue, 18 Jun 2024 16:46:38 +0800 Message-Id: <20240618084639.1419629-3-ying.huang@intel.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240618084639.1419629-1-ying.huang@intel.com> References: <20240618084639.1419629-1-ying.huang@intel.com> Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 An abstract distance value must be assigned by the driver that makes the memory available to the system. It reflects relative performance and is used to place memory nodes backed by CXL regions in the appropriate memory tiers allowing promotion/demotion within the existing memory tiering mechanism. The abstract distance is calculated based on the memory access latency and bandwidth of CXL regions. Signed-off-by: "Huang, Ying" Acked-by: Dan Williams Cc: Alison Schofield Cc: Andrew Morton Cc: Jonathan Cameron Cc: Dave Jiang Cc: Bharata B Rao Cc: Alistair Popple Cc: Aneesh Kumar K.V Cc: Davidlohr Bueso Cc: Vishal Verma Cc: Ira Weiny Reviewed-by: Jonathan Cameron --- drivers/cxl/core/region.c | 27 +++++++++++++++++++++++++++ drivers/cxl/cxl.h | 2 ++ 2 files changed, 29 insertions(+) diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 51aeef2c012c..dc15ceba7ab7 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include "core.h" @@ -2228,6 +2229,7 @@ static void unregister_region(void *_cxlr) int i; unregister_memory_notifier(&cxlr->memory_notifier); + unregister_mt_adistance_algorithm(&cxlr->adist_notifier); device_del(&cxlr->dev); /* @@ -2340,6 +2342,27 @@ static int cxl_region_perf_attrs_callback(struct notifier_block *nb, return NOTIFY_OK; } +static int cxl_region_calculate_adistance(struct notifier_block *nb, + unsigned long nid, void *data) +{ + struct cxl_region *cxlr = container_of(nb, struct cxl_region, + adist_notifier); + struct access_coordinate *perf; + int *adist = data; + int region_nid; + + region_nid = cxl_region_nid(cxlr); + if (nid != region_nid) + return NOTIFY_OK; + + perf = &cxlr->coord[ACCESS_COORDINATE_CPU]; + + if (mt_perf_to_adistance(perf, adist)) + return NOTIFY_OK; + + return NOTIFY_STOP; +} + /** * devm_cxl_add_region - Adds a region to a decoder * @cxlrd: root decoder @@ -2382,6 +2405,10 @@ static struct cxl_region *devm_cxl_add_region(struct cxl_root_decoder *cxlrd, cxlr->memory_notifier.priority = CXL_CALLBACK_PRI; register_memory_notifier(&cxlr->memory_notifier); + cxlr->adist_notifier.notifier_call = cxl_region_calculate_adistance; + cxlr->adist_notifier.priority = 100; + register_mt_adistance_algorithm(&cxlr->adist_notifier); + rc = devm_add_action_or_reset(port->uport_dev, unregister_region, cxlr); if (rc) return ERR_PTR(rc); diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index 603c0120cff8..f46252373159 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -522,6 +522,7 @@ struct cxl_region_params { * @params: active + config params for the region * @coord: QoS access coordinates for the region * @memory_notifier: notifier for setting the access coordinates to node + * @adist_notifier: notifier for calculating the abstract distance of node */ struct cxl_region { struct device dev; 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d="scan'208";a="78933659" Received: from shilinmu-mobl.ccr.corp.intel.com (HELO yhuang6-mobl2.ccr.corp.intel.com) ([10.255.28.204]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Jun 2024 01:47:02 -0700 From: Huang Ying To: Dan Williams , Dave Jiang Cc: linux-cxl@vger.kernel.org, linux-kernel@vger.kernel.org, Huang Ying , Alison Schofield , Andrew Morton , Jonathan Cameron , Bharata B Rao , Alistair Popple , "Aneesh Kumar K . V" , Davidlohr Bueso , Vishal Verma , Ira Weiny Subject: [PATCH v3 3/3] cxl/region: Simplify cxl_region_nid() Date: Tue, 18 Jun 2024 16:46:39 +0800 Message-Id: <20240618084639.1419629-4-ying.huang@intel.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240618084639.1419629-1-ying.huang@intel.com> References: <20240618084639.1419629-1-ying.huang@intel.com> Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 The node ID of the region can be gotten via resource start address directly. This simplifies the implementation of cxl_region_nid(). Signed-off-by: "Huang, Ying" Suggested-by: Alison Schofield Cc: Dan Williams Cc: Andrew Morton Cc: Jonathan Cameron Cc: Dave Jiang Cc: Bharata B Rao Cc: Alistair Popple Cc: Aneesh Kumar K.V Cc: Davidlohr Bueso Cc: Vishal Verma Cc: Ira Weiny Reviewed-by: Jonathan Cameron --- drivers/cxl/core/region.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index dc15ceba7ab7..605efe3562c6 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -2309,15 +2309,13 @@ static bool cxl_region_update_coordinates(struct cxl_region *cxlr, int nid) static int cxl_region_nid(struct cxl_region *cxlr) { struct cxl_region_params *p = &cxlr->params; - struct cxl_endpoint_decoder *cxled; - struct cxl_decoder *cxld; + struct resource *res; guard(rwsem_read)(&cxl_region_rwsem); - cxled = p->targets[0]; - if (!cxled) + res = p->res; + if (!res) return NUMA_NO_NODE; - cxld = &cxled->cxld; - return phys_to_target_node(cxld->hpa_range.start); + return phys_to_target_node(res->start); } static int cxl_region_perf_attrs_callback(struct notifier_block *nb,