From nobody Tue Nov 26 17:14:59 2024 Received: from pv50p00im-tydg10011801.me.com (pv50p00im-tydg10011801.me.com [17.58.6.52]) (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 DEDA51D2700 for ; Wed, 16 Oct 2024 21:59:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=17.58.6.52 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729115944; cv=none; b=qQCQshpoULhoT4b33tZ6d44s09b8x9Pty2NZ8tvM5mwoxqyI7DuzlJz+tJIeDF8aCT+CpEUxNhIzC6GP2llX+CvyYYGpzt2qn38gkH+2y7LjJ6RkvkFUbqOYoxOrSHap7G7MZkz2FBzHe/dapHlvFkIQqdIUiJvoy/8kt+Cay4k= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729115944; c=relaxed/simple; bh=VM5AoH77kamG/P8FfHaTplWWh9Ri6fOxL2aXoCutNPQ=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=usO73XM7tji5kTB8vwJvGRaozkbfL/WwwEF1yDiEV+3w5bnVpk0ROS8FLBTlcuTUfT9rONZyRzJW7jy1g0naxHjrD9zmG6ZYx1BNh/LFKRMMx9HPfYCIcgncU0VZAzYYOuCVhrrky5xphBbVhtgcffwjSaNJDjUcX2VsWsBN1d4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=icloud.com; spf=pass smtp.mailfrom=icloud.com; dkim=pass (2048-bit key) header.d=icloud.com header.i=@icloud.com header.b=WXPgRGfA; arc=none smtp.client-ip=17.58.6.52 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=icloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=icloud.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=icloud.com header.i=@icloud.com header.b="WXPgRGfA" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=icloud.com; s=1a1hai; t=1729115942; bh=Lm6OJ4ppqsx00EFeKk98+BP9777KWhMrNiTij1ST0DU=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To; b=WXPgRGfAGSBQ00OKL/S5QnnHalfxPHj6QKQmVCvcPeapY5Lgm1PTEoSJ18eXZWB9Y GI4ox1dbRj505boKls9Koc5HhS9U/rwJgG2DSf/IC3RRAlGGbCai/WV2ysYZOToF0D jgrKMq3twbf4+eXR9HNunIKFU1pwb4oY2u83dZ81pj6jXFMR0y7xe4mcyoo51jOFx2 C1WGEkAp6jn70HYnSq96ag+Xt2QMNJsoqUCPfjkZgXQ9o5vIYS6lOeXZqkST0uYZZY feYqqkWjGhjqxHHRhOvkSxAPRrktGwofq0K0Y8vh9YNCQJZK0QU1Q8QPtqelZsR5Em OjDa0WEp8Z3qQ== Received: from [192.168.1.26] (pv50p00im-dlb-asmtp-mailmevip.me.com [17.56.9.10]) by pv50p00im-tydg10011801.me.com (Postfix) with ESMTPSA id 5E01D800198; Wed, 16 Oct 2024 21:58:57 +0000 (UTC) From: Zijun Hu Date: Thu, 17 Oct 2024 05:57:40 +0800 Subject: [PATCH v6] cxl/region: Fix wrong logic for finding a free switch cxl decoder Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20241017-const_dfc_prepare-v6-1-fc842264a1cc@quicinc.com> X-B4-Tracking: v=1; b=H4sIANM2EGcC/33QwU7DMAwG4FeZciYosZMm5cR7IDSlicNyoB3Jq EBT3x1vF4pacfx/yZ8tX0WjWqiJp8NVVJpLK9PIoXs4iHgK4xvJkjgLUGCU11rGaWyXY8rxeK5 0DpUk5gwYO9t7soLnuM/l626+vHI+lXaZ6vd9xaxv7X/arKWSqXMxGt0NmPD547PEMsbHOL2Lm zfD2rB7BrDhkee9G3zO/dbAlQFmz0A2EDQ4CgjDELaG+TV6tXuHYcNor0gnG8CYrWFXhnZ7hpX 8EQKVO4dEKv41lmX5AcF4FVTEAQAA To: Greg Kroah-Hartman , Davidlohr Bueso , Jonathan Cameron , Dave Jiang , Alison Schofield , Vishal Verma , Ira Weiny , Dan Williams Cc: Przemek Kitszel , Zijun Hu , linux-cxl@vger.kernel.org, linux-kernel@vger.kernel.org, Zijun Hu X-Mailer: b4 0.14.1 X-Proofpoint-GUID: NTtQUb32VILvAfHfVNv7Kp5Uzly96Dx_ X-Proofpoint-ORIG-GUID: NTtQUb32VILvAfHfVNv7Kp5Uzly96Dx_ X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.1051,Hydra:6.0.680,FMLib:17.12.62.30 definitions=2024-10-16_17,2024-10-16_01,2024-09-30_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 spamscore=0 suspectscore=0 malwarescore=0 clxscore=1015 adultscore=0 mlxlogscore=999 bulkscore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2308100000 definitions=main-2410160140 X-Apple-Remote-Links: v=1;h=KCk=;charset=UTF-8 From: Zijun Hu Provided that all child switch cxl decoders are sorted by ID in ascending order, then it is wrong for current match_free_decoder()'s logic to find a free cxl decoder as explained below: Port =E2=94=9C=E2=94=80=E2=94=80 cxld A <----> region A =E2=94=9C=E2=94=80=E2=94=80 cxld B // no region =E2=94=9C=E2=94=80=E2=94=80 cxld C <----> region C Current logic will find cxld B as a free one, but cxld B is not true free since region C has not been torn down, so current logic is wrong. Fixed by verifying if cxl decoder with ID (@port->commit_end + 1) can be returned as finding result. Link: https://lore.kernel.org/all/670af54931b8_964fe29427@dwillia2-xfh.jf.i= ntel.com.notmuch/ Suggested-by: Dan Williams Signed-off-by: Zijun Hu Reported-by: Zijun Hu Reported-by: Zijun Hu --- This patch is incremental to below patch series with title "cxl: Initializa= tion and shutdown fixes" http://lore.kernel.org/172862483180.2150669.5564474284074502692.stgit@dwill= ia2-xfh.jf.intel.com This patch is based on Dan's recommendation shown by below link: https://lore.kernel.org/all/670af54931b8_964fe29427@dwillia2-xfh.jf.intel.c= om.notmuch/ --- Changes in v6: - Use Dan's recommendation that validate clxd with ID (@port->commit_end + = 1) - Correct commit message and update Link tag this commit derive from - Link to v5: https://lore.kernel.org/r/20240917-const_dfc_prepare-v5-1-0e2= 0f673ee0c@quicinc.com Changes in v5: - Use changes suggested by Dan Williams for cxl/region patch - Correct title and commit message for cxl/region change - Seperate qcom/emac change for patch series - Link to v4: https://lore.kernel.org/r/20240905-const_dfc_prepare-v4-0-418= 0e1d5a244@quicinc.com Changes in v4: - Drop driver core patch - Correct commit message for cxl/region patch - Correct title and commit message for qcom/emac patch - Link to v3: https://lore.kernel.org/r/20240824-const_dfc_prepare-v3-0-321= 27ea32bba@quicinc.com Changes in v3: - Git rebase - Correct commit message for the driver core patch - Use changes suggested by Ira Weiny cxl/region - Drop firewire core patch - Make qcom/emac follow cxl/region solution suggested by Greg - Link to v2: https://lore.kernel.org/r/20240815-const_dfc_prepare-v2-0-831= 6b87b8ff9@quicinc.com Changes in v2: - Give up introducing the API constify_device_find_child_helper() - Correct commit message and inline comments - Implement a driver specific and equivalent one instead of device_find_chi= ld() - Link to v1: https://lore.kernel.org/r/20240811-const_dfc_prepare-v1-0-d67= cc416b3d3@quicinc.com --- drivers/cxl/core/region.c | 35 +++++++++++++++++++++++------------ 1 file changed, 23 insertions(+), 12 deletions(-) diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index e701e4b04032..a7a82da39393 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -796,8 +796,9 @@ static size_t show_targetN(struct cxl_region *cxlr, cha= r *buf, int pos) =20 static int match_free_decoder(struct device *dev, void *data) { + struct cxl_port *port =3D to_cxl_port(dev->parent); struct cxl_decoder *cxld; - int *id =3D data; + struct device **target_dev =3D data; =20 if (!is_switch_decoder(dev)) return 0; @@ -805,15 +806,24 @@ static int match_free_decoder(struct device *dev, voi= d *data) cxld =3D to_cxl_decoder(dev); =20 /* enforce ordered allocation */ - if (cxld->id !=3D *id) - return 0; + if (cxld->id =3D=3D port->commit_end + 1) { + if (!cxld->region) { + *target_dev =3D dev; + return 1; + } =20 - if (!cxld->region) - return 1; + dev_dbg(dev->parent, + "%s: cxld '%s' was reserved by '%s'\n", __func__, + dev_name(dev), dev_name(&cxld->region->dev)); + return -EBUSY; + } =20 - (*id)++; + if (cxld->flags & CXL_DECODER_F_ENABLE) + return 0; =20 - return 0; + dev_dbg(dev->parent, "%s: cxld '%s' was out of order shut down\n", + __func__, dev_name(dev)); + return -EINVAL; } =20 static int match_auto_decoder(struct device *dev, void *data) @@ -839,17 +849,18 @@ cxl_region_find_decoder(struct cxl_port *port, struct cxl_endpoint_decoder *cxled, struct cxl_region *cxlr) { - struct device *dev; - int id =3D 0; + struct device *dev =3D NULL; =20 if (port =3D=3D cxled_to_port(cxled)) return &cxled->cxld; =20 - if (test_bit(CXL_REGION_F_AUTO, &cxlr->flags)) + if (test_bit(CXL_REGION_F_AUTO, &cxlr->flags)) { dev =3D device_find_child(&port->dev, &cxlr->params, match_auto_decoder); - else - dev =3D device_find_child(&port->dev, &id, match_free_decoder); + } else { + device_for_each_child(&port->dev, &dev, match_free_decoder); + get_device(dev); + } if (!dev) return NULL; /* --- base-commit: 9bd133f05b1dca5ca4399a76d04d0f6f4d454e44 change-id: 20240811-const_dfc_prepare-3ff23c6598e5 Best regards, --=20 Zijun Hu