From patchwork Mon Feb 6 01:03:02 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 650997 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 ECE20C636CC for ; Mon, 6 Feb 2023 01:03:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229533AbjBFBDG (ORCPT ); Sun, 5 Feb 2023 20:03:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53208 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229537AbjBFBDE (ORCPT ); Sun, 5 Feb 2023 20:03:04 -0500 Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2ABF7144B4; Sun, 5 Feb 2023 17:03:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1675645383; x=1707181383; h=subject:from:to:cc:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=gxV5boq5z7i+vQyYxApsVbkxX+I+JHzPNbJoiDtgews=; b=XNfxh7Guj5o3I0pbrQJOsQxMwAt3pCT5WR46zYQtPuCaoX/yVq6Y6SlZ H6CT1JC/gqRaXGS2ue+gybJReMgZLe/KDnbR3rICH/CNE5s7J3a5TD15/ 9tri7gck7nODENbdi7l5O1Y8VHjsCPcQP8SOVB95IRTL1w/zhzjz/6Sh9 it/UhQt05OXiih7Nvr5TUf+QNxfAl+i5pCiFnnymFSncQROqjkMLtdiDM /I5YB6ogI+6tp8Is5moLM4h8gYn88XRdNulRgduUiu1XvtJIaEcdmgp8I Q1Yl9ORP8KCfl9DYCYR0YX1mBNynCRlVCez4DJAAuLY0VI23JtiV9yXDo w==; X-IronPort-AV: E=McAfee;i="6500,9779,10612"; a="312763180" X-IronPort-AV: E=Sophos;i="5.97,276,1669104000"; d="scan'208";a="312763180" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Feb 2023 17:03:02 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10612"; a="616291294" X-IronPort-AV: E=Sophos;i="5.97,276,1669104000"; d="scan'208";a="616291294" Received: from mkrysak-mobl.amr.corp.intel.com (HELO dwillia2-xfh.jf.intel.com) ([10.212.255.187]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Feb 2023 17:03:02 -0800 Subject: [PATCH 06/18] cxl/region: Refactor attach_target() for autodiscovery From: Dan Williams To: linux-cxl@vger.kernel.org Cc: dave.hansen@linux.intel.com, linux-mm@kvack.org, linux-acpi@vger.kernel.org Date: Sun, 05 Feb 2023 17:03:02 -0800 Message-ID: <167564538227.847146.16305045998592488364.stgit@dwillia2-xfh.jf.intel.com> In-Reply-To: <167564534874.847146.5222419648551436750.stgit@dwillia2-xfh.jf.intel.com> References: <167564534874.847146.5222419648551436750.stgit@dwillia2-xfh.jf.intel.com> User-Agent: StGit/0.18-3-g996c MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org Region autodiscovery is the process of kernel creating 'struct cxl_region' object to represent active CXL memory ranges it finds already active in hardware when the driver loads. Typically this happens when platform firmware establishes CXL memory regions and then publishes them in the memory map. However, this can also happen in the case of kexec-reboot after the kernel has created regions. In the autodiscovery case the region creation process starts with a known endpoint decoder. Refactor attach_target() into a helper that is suitable to be called from either sysfs, for runtime region creation, or from cxl_port_probe() after it has enumerated all endpoint decoders. The cxl_port_probe() context is an async device-core probing context, so it is not appropriate to allow SIGTERM to interrupt the assembly process. Refactor attach_target() to take @cxled and @state as arguments where @state indicates whether waiting from the region rwsem is interruptible or not. No behavior change is intended. Signed-off-by: Dan Williams Reviewed-by: Dave Jiang Reviewed-by: Vishal Verma --- drivers/cxl/core/region.c | 47 +++++++++++++++++++++++++++------------------ 1 file changed, 28 insertions(+), 19 deletions(-) diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 8dea49c021b8..97eafdd75675 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -1418,31 +1418,25 @@ void cxl_decoder_kill_region(struct cxl_endpoint_decoder *cxled) up_write(&cxl_region_rwsem); } -static int attach_target(struct cxl_region *cxlr, const char *decoder, int pos) +static int attach_target(struct cxl_region *cxlr, + struct cxl_endpoint_decoder *cxled, int pos, + unsigned int state) { - struct device *dev; - int rc; - - dev = bus_find_device_by_name(&cxl_bus_type, NULL, decoder); - if (!dev) - return -ENODEV; - - if (!is_endpoint_decoder(dev)) { - put_device(dev); - return -EINVAL; - } + int rc = 0; - rc = down_write_killable(&cxl_region_rwsem); + if (state == TASK_INTERRUPTIBLE) + rc = down_write_killable(&cxl_region_rwsem); + else + down_write(&cxl_region_rwsem); if (rc) - goto out; + return rc; + down_read(&cxl_dpa_rwsem); - rc = cxl_region_attach(cxlr, to_cxl_endpoint_decoder(dev), pos); + rc = cxl_region_attach(cxlr, cxled, pos); if (rc == 0) set_bit(CXL_REGION_F_INCOHERENT, &cxlr->flags); up_read(&cxl_dpa_rwsem); up_write(&cxl_region_rwsem); -out: - put_device(dev); return rc; } @@ -1480,8 +1474,23 @@ static size_t store_targetN(struct cxl_region *cxlr, const char *buf, int pos, if (sysfs_streq(buf, "\n")) rc = detach_target(cxlr, pos); - else - rc = attach_target(cxlr, buf, pos); + else { + struct device *dev; + + dev = bus_find_device_by_name(&cxl_bus_type, NULL, buf); + if (!dev) + return -ENODEV; + + if (!is_endpoint_decoder(dev)) { + rc = -EINVAL; + goto out; + } + + rc = attach_target(cxlr, to_cxl_endpoint_decoder(dev), pos, + TASK_INTERRUPTIBLE); +out: + put_device(dev); + } if (rc < 0) return rc;