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Wed, 5 Aug 2026 13:36:27 +0000 (GMT) From: Heiko Carstens To: Alexander Gordeev , Sven Schnelle , Vasily Gorbik , Christian Borntraeger , Niklas Schnelle , Gerd Bayer Cc: linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 1/3] s390/pci: Rework __zpci_event_error() to remove conditional locking Date: Wed, 5 Aug 2026 15:36:25 +0200 Message-ID: <20260805133627.1216607-2-hca@linux.ibm.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260805133627.1216607-1-hca@linux.ibm.com> References: <20260805133627.1216607-1-hca@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-Spam-Info: AW1haW4tMjYwODA1MDEwNyBTYWx0ZWRfX/EEDngJtZxab eagSwkeeqaeY/h6wOmJ6I3QJxQPb/ferwtpGr1iF/f+vnAPqryQSBXbAJxvNgQF+1WslIchAf47 OazeMd0f458M1f/1DX3hdi9RFJoP2Og= X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwODA1MDEwNyBTYWx0ZWRfX4Vu9amLbwZKU 4u9tIVIRvWeGHJCHYEFsKA1RvD4n7eQX0m8IqI2Sw1TBWIaYqo6qIYO9DSU86dODkcvR0kOKlwW PIzt7Pu0w2sOrQEugWAwNqC6u1K1u2la0GG3BINCT6Hr/3zj9oC45GFroq4ARCtoEToMX/5SKha 4ceQNUXmyI8G5lOhRx+R47TzxQlxGlBC3Q9BI+tUY1y4VKzqjQwImHQJtKWGmJEJm8HDZltSJGn wuERIJPWanN9yBkE0mOm2kns1Cn1hH1K++6i6PhawG1Vbt4+tF7u8eEEhfswgNRAVCvQ1rfAnNP KWwBSPDt+LDa5TuQ1RdnONHSE+GX3C2Hdv+PcREzNDkMlhzm54Bm6xxnE+vaBaev6gMXuFFpd3S Y7IcTrw7P4t7YT9KCuA9lsov+ms41doeTOC2+Pw3W6K9p+5Yi6XNF/bnyBjVVZ1uKGdDsy4MRRj pCfbIyW4Y4HYzugvNbA== X-Authority-Analysis: v=2.4 cv=SI1ykuvH c=1 sm=1 tr=0 ts=6a733c60 cx=c_pps a=aDMHemPKRhS1OARIsFnwRA==:117 a=aDMHemPKRhS1OARIsFnwRA==:17 a=Sv0fKeRqtYgA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=U7nrCbtTmkRpXpFmAIza:22 a=VnNF1IyMAAAA:8 a=m4_1mmLPwvc7V99NFaoA:9 X-Proofpoint-ORIG-GUID: DDw7hS_eEUxvq7YJwH8zBX1Lid_vvX0o X-Proofpoint-GUID: DDw7hS_eEUxvq7YJwH8zBX1Lid_vvX0o X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1176,Hydra:6.1.134,FMLib:17.12.100.49 definitions=2026-08-05_04,2026-08-04_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 bulkscore=0 suspectscore=0 impostorscore=0 spamscore=0 phishscore=0 priorityscore=1501 lowpriorityscore=0 adultscore=0 malwarescore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2608050107 Clang's compiler based static context analysis does not work with locks that are conditionally taken like in __zpci_event_error(): arch/s390/pci/pci_event.c:320:2: warning: mutex 'get_zdev_by_fid(ccdf->fid).state_lock' is not held on every path through here [-Wthread-safety-analysis] Given that code which takes locks conditionally can be considered suboptimal rework __zpci_event_error() to get rid of this. Reviewed-by: Niklas Schnelle Signed-off-by: Heiko Carstens --- arch/s390/pci/pci_event.c | 43 ++++++++++++++++++++++----------------- 1 file changed, 24 insertions(+), 19 deletions(-) diff --git a/arch/s390/pci/pci_event.c b/arch/s390/pci/pci_event.c index 839bd91c056e..bead4ed5d4ab 100644 --- a/arch/s390/pci/pci_event.c +++ b/arch/s390/pci/pci_event.c @@ -288,6 +288,12 @@ static void zpci_event_io_failure(struct pci_dev *pdev, pci_channel_state_t es) pci_dev_unlock(pdev); } +static void __zpci_event_print_error(struct pci_dev *pdev, struct zpci_ccdf_err *ccdf) +{ + pr_err("%s: Event 0x%x reports an error for PCI function 0x%x\n", + pdev ? pci_name(pdev) : "n/a", ccdf->pec, ccdf->fid); +} + static void __zpci_event_error(struct zpci_ccdf_err *ccdf) { struct zpci_dev *zdev = get_zdev_by_fid(ccdf->fid); @@ -301,24 +307,24 @@ static void __zpci_event_error(struct zpci_ccdf_err *ccdf) zpci_err("error CCDF:\n"); zpci_err_hex(ccdf, sizeof(*ccdf)); - if (zdev) { - mutex_lock(&zdev->state_lock); - rc = clp_refresh_fh(zdev->fid, &fh); - if (rc) - goto no_pdev; - if (!fh || ccdf->fh != fh) { - /* Ignore events with stale handles */ - zpci_dbg(3, "err fid:%x, fh:%x (stale %x)\n", - ccdf->fid, fh, ccdf->fh); - goto no_pdev; - } - zpci_update_fh(zdev, ccdf->fh); - if (zdev->zbus->bus) - pdev = pci_get_slot(zdev->zbus->bus, zdev->devfn); - } + if (!zdev) + return __zpci_event_print_error(NULL, ccdf); - pr_err("%s: Event 0x%x reports an error for PCI function 0x%x\n", - pdev ? pci_name(pdev) : "n/a", ccdf->pec, ccdf->fid); + mutex_lock(&zdev->state_lock); + rc = clp_refresh_fh(zdev->fid, &fh); + if (rc) + goto no_pdev; + if (!fh || ccdf->fh != fh) { + /* Ignore events with stale handles */ + zpci_dbg(3, "err fid:%x, fh:%x (stale %x)\n", + ccdf->fid, fh, ccdf->fh); + goto no_pdev; + } + zpci_update_fh(zdev, ccdf->fh); + if (zdev->zbus->bus) + pdev = pci_get_slot(zdev->zbus->bus, zdev->devfn); + + __zpci_event_print_error(pdev, ccdf); if (!pdev) goto no_pdev; @@ -340,8 +346,7 @@ static void __zpci_event_error(struct zpci_ccdf_err *ccdf) } pci_dev_put(pdev); no_pdev: - if (zdev) - mutex_unlock(&zdev->state_lock); + mutex_unlock(&zdev->state_lock); zpci_zdev_put(zdev); } -- 2.53.0