From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:55434 "EHLO mx0b-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728346AbgI2NHw (ORCPT ); Tue, 29 Sep 2020 09:07:52 -0400 Subject: Re: [PATCH v10 02/16] s390/vfio-ap: use new AP bus interface to search for queue devices References: <20200821195616.13554-1-akrowiak@linux.ibm.com> <20200821195616.13554-3-akrowiak@linux.ibm.com> <20200925042729.3b9d5704.pasic@linux.ibm.com> From: Tony Krowiak Message-ID: Date: Tue, 29 Sep 2020 09:07:40 -0400 MIME-Version: 1.0 In-Reply-To: <20200925042729.3b9d5704.pasic@linux.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US List-ID: To: Halil Pasic Cc: linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, freude@linux.ibm.com, borntraeger@de.ibm.com, cohuck@redhat.com, mjrosato@linux.ibm.com, alex.williamson@redhat.com, kwankhede@nvidia.com, fiuczy@linux.ibm.com, frankja@linux.ibm.com, david@redhat.com, imbrenda@linux.ibm.com, hca@linux.ibm.com, gor@linux.ibm.com, kernel test robot On 9/24/20 10:27 PM, Halil Pasic wrote: > On Fri, 21 Aug 2020 15:56:02 -0400 > Tony Krowiak wrote: > >> --- a/drivers/s390/crypto/vfio_ap_ops.c >> +++ b/drivers/s390/crypto/vfio_ap_ops.c >> @@ -26,43 +26,26 @@ >> >> static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev); >> >> -static int match_apqn(struct device *dev, const void *data) >> -{ >> - struct vfio_ap_queue *q = dev_get_drvdata(dev); >> - >> - return (q->apqn == *(int *)(data)) ? 1 : 0; >> -} >> - >> /** >> - * vfio_ap_get_queue: Retrieve a queue with a specific APQN from a list >> - * @matrix_mdev: the associated mediated matrix >> + * vfio_ap_get_queue: Retrieve a queue with a specific APQN. >> * @apqn: The queue APQN >> * >> - * Retrieve a queue with a specific APQN from the list of the >> - * devices of the vfio_ap_drv. >> - * Verify that the APID and the APQI are set in the matrix. >> + * Retrieve a queue with a specific APQN from the AP queue devices attached to >> + * the AP bus. >> * >> - * Returns the pointer to the associated vfio_ap_queue >> + * Returns the pointer to the vfio_ap_queue with the specified APQN, or NULL. >> */ >> -static struct vfio_ap_queue *vfio_ap_get_queue( >> - struct ap_matrix_mdev *matrix_mdev, >> - int apqn) >> +static struct vfio_ap_queue *vfio_ap_get_queue(unsigned long apqn) >> { >> + struct ap_queue *queue; >> struct vfio_ap_queue *q; >> - struct device *dev; >> >> - if (!test_bit_inv(AP_QID_CARD(apqn), matrix_mdev->matrix.apm)) >> - return NULL; >> - if (!test_bit_inv(AP_QID_QUEUE(apqn), matrix_mdev->matrix.aqm)) >> + queue = ap_get_qdev(apqn); >> + if (!queue) >> return NULL; >> >> - dev = driver_find_device(&matrix_dev->vfio_ap_drv->driver, NULL, >> - &apqn, match_apqn); >> - if (!dev) >> - return NULL; >> - q = dev_get_drvdata(dev); >> - q->matrix_mdev = matrix_mdev; >> - put_device(dev); >> + q = dev_get_drvdata(&queue->ap_dev.device); > Is this cast here safe? (I don't think it is.) In the probe, we execute: dev_set_drvdata(&queue->ap_dev.device, q); I don't get any compile nor execution errors. Why wouldn't it be safe? > >> + put_device(&queue->ap_dev.device); >> >> return q; >> }