From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jacob Pan Subject: Re: [PATCH v3 10/16] iommu: introduce device fault report API Date: Tue, 23 Jan 2018 12:01:38 -0800 Message-ID: <20180123120138.787d1f81@jacob-builder> References: <1510944914-54430-1-git-send-email-jacob.jun.pan@linux.intel.com> <1510944914-54430-11-git-send-email-jacob.jun.pan@linux.intel.com> <6eea3b27-d0ca-8021-325f-fdc876ebf113@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <6eea3b27-d0ca-8021-325f-fdc876ebf113@arm.com> Sender: linux-kernel-owner@vger.kernel.org To: Jean-Philippe Brucker Cc: "iommu@lists.linux-foundation.org" , LKML , Joerg Roedel , David Woodhouse , Greg Kroah-Hartman , Rafael Wysocki , Alex Williamson , Lan Tianyu , jacob.jun.pan@linux.intel.com List-Id: iommu@lists.linux-foundation.org On Thu, 18 Jan 2018 19:24:52 +0000 Jean-Philippe Brucker wrote: > Hi Jacob, > > I've got minor comments after working with this patch, sorry for the > multiple replies > > On 17/11/17 18:55, Jacob Pan wrote: > [...] > > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c > > index 829e9e9..97b7990 100644 > > --- a/drivers/iommu/iommu.c > > +++ b/drivers/iommu/iommu.c > > @@ -581,6 +581,12 @@ int iommu_group_add_device(struct iommu_group > > *group, struct device *dev) goto err_free_name; > > } > > > > + dev->iommu_param = kzalloc(sizeof(struct > > iommu_fault_param), GFP_KERNEL); > > This should be "sizeof(struct iommu_param)" or maybe > "sizeof(*dev->iommu_param)". > good catch, thanks, > > + if (!dev->iommu_param) { > > + ret = -ENOMEM; > > + goto err_free_name; > > + } > > + > > kobject_get(group->devices_kobj); > > > > dev->iommu_group = group; > > @@ -657,7 +663,7 @@ void iommu_group_remove_device(struct device > > *dev) sysfs_remove_link(&dev->kobj, "iommu_group"); > > > > trace_remove_device_from_group(group->id, dev); > > - > > + kfree(dev->iommu_param); > > kfree(device->name); > > kfree(device); > > dev->iommu_group = NULL; > > @@ -791,6 +797,61 @@ int iommu_group_unregister_notifier(struct > > iommu_group *group, } > > EXPORT_SYMBOL_GPL(iommu_group_unregister_notifier); > > > > +int iommu_register_device_fault_handler(struct device *dev, > > + iommu_dev_fault_handler_t > > handler, > > + void *data) > > +{ > > + struct iommu_param *idata = dev->iommu_param; > > + > > + /* > > + * Device iommu_param should have been allocated when > > device is > > + * added to its iommu_group. > > + */ > > + if (!idata) > > + return -EINVAL; > > + /* Only allow one fault handler registered for each device > > */ > > + if (idata->fault_param) > > + return -EBUSY; > > + get_device(dev); > > + idata->fault_param = > > + kzalloc(sizeof(struct iommu_fault_param), > > GFP_KERNEL); > > + if (!idata->fault_param) > > + return -ENOMEM; > > + idata->fault_param->handler = handler; > > + idata->fault_param->data = data; > > + > > + return 0; > > +} > > +EXPORT_SYMBOL_GPL(iommu_register_device_fault_handler); > > + > > +int iommu_unregister_device_fault_handler(struct device *dev) > > +{ > > + struct iommu_param *idata = dev->iommu_param; > > + > > + if (!idata) > > + return -EINVAL; > > + > > + kfree(idata->fault_param); > > + idata->fault_param = NULL; > > + put_device(dev); > > + > > + return 0; > > +} > > +EXPORT_SYMBOL_GPL(iommu_unregister_device_fault_handler); > > We should probably document register() and unregister() functions > since they are part of the device driver API. If it helps I came up > with: > > /** > * iommu_register_device_fault_handler() - Register a device fault > handler > * @dev: the device > * @handler: the fault handler > * @data: private data passed as argument to the handler > * > * When an IOMMU fault event is received, call this handler with the > fault event > * and data as argument. The handler should return 0. If the fault is > * recoverable (IOMMU_FAULT_PAGE_REQ), the handler must also complete > * the fault by calling iommu_page_response() with one of the > following > * response code: > * - IOMMU_PAGE_RESP_SUCCESS: retry the translation > * - IOMMU_PAGE_RESP_INVALID: terminate the fault > * - IOMMU_PAGE_RESP_FAILURE: terminate the fault and stop reporting > * page faults if possible. > * > * Return 0 if the fault handler was installed successfully, or an > error. */ > > /** > * iommu_unregister_device_fault_handler() - Unregister the device > fault handler > * @dev: the device > * > * Remove the device fault handler installed with > * iommu_register_device_fault_handler(). > * > * Return 0 on success, or an error. > */ > agreed. thanks. sorry about the delay. > Thanks, > Jean [Jacob Pan]