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Mon, 3 Aug 2026 10:07:23 +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 1/3] s390/pci: Rework __zpci_event_error() to remove conditional locking Date: Mon, 3 Aug 2026 12:07:21 +0200 Message-ID: <20260803100723.2343688-2-hca@linux.ibm.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260803100723.2343688-1-hca@linux.ibm.com> References: <20260803100723.2343688-1-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-Details-Enc: AW1haW4tMjYwODAzMDA4NyBTYWx0ZWRfX1iymzai4PP5Q +tpvmH3Ro1i2kvTGudF3BaFEwQhuVkWzPESTRFEfwJC+pUdXszmrKA20F089Y/ffRG4XjuJMAnR coyTKVZNX1ezoG1v3WXQiRWtLogUinxIpCKl/jJnPXN2OMOhFPg4tprZHXFQHP4dQOCNVvSBpLy TBsyB6xBZLMCLHPeHESAYgwvM6cfrmZvvHVZkYksKqNFuBfmUuHaPK5DWUgmLhOOhX2zwziFKGe veuPMdM0WghMLwrj8dHKGMxfeKuXPNXK9iF+rdIZf9RWLrdlML1abZVM5PcFqTzDxMYYlS30Tyw YRf2fWp9lSz1xyjTR5PRlXheRsFZw+vcLBPov4kXUQ+7xm8iphWztuVMn+ogi0UIwhJahYWVf1O rYxGG6CIUsoFJce7+tTJG6CZ57i4xTwmEoUhPPxjUddMjawBiezecPVdbz3+4KmnYZRfOtyAaSq nWiEMPCp6bG+QIAnV9w== X-Authority-Analysis: v=2.4 cv=WIFPmHsR c=1 sm=1 tr=0 ts=6a706861 cx=c_pps a=GFwsV6G8L6GxiO2Y/PsHdQ==:117 a=GFwsV6G8L6GxiO2Y/PsHdQ==:17 a=Sv0fKeRqtYgA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=V8glGbnc2Ofi9Qvn3v5h:22 a=VnNF1IyMAAAA:8 a=m4_1mmLPwvc7V99NFaoA:9 X-Proofpoint-GUID: fWsDUe7asRME3VIFEMxmyjym9k-Vdg2- X-Proofpoint-ORIG-GUID: fWsDUe7asRME3VIFEMxmyjym9k-Vdg2- X-Proofpoint-Spam-Info: AW1haW4tMjYwODAzMDA4NyBTYWx0ZWRfXxsYGm6wc9z09 6+Yc8k4S68XFBT/+/o4S/oj2zb+QgDG1liMoMqIQw6zxz8GS4JEtWSQKTaawwvEWAayVDjnWgoP ClLvFOGImgis5HqqUUT4MjqVUKzpUWM= X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.134,FMLib:17.12.100.49 definitions=2026-08-02_06,2026-07-30_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 lowpriorityscore=0 priorityscore=1501 phishscore=0 malwarescore=0 suspectscore=0 clxscore=1015 impostorscore=0 bulkscore=0 adultscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2608030087 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. 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..48fa26dcbee1 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(pdev, 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