On 2023/3/29 0:51, Jonathan Cameron wrote:
> On Wed, 15 Mar 2023 17:43:14 +0800
> Yicong Yang <yangyicong@xxxxxxxxxx> wrote:
>
>> From: Yicong Yang <yangyicong@xxxxxxxxxxxxx>
>>
>> The PCIe devices supported by the PTT trace can be removed/rescanned by
>> hotplug or through sysfs. Add support for dynamically updating the
>> available filter list by registering a PCI bus notifier block. Then user
>> can always get latest information about available tracing filters and
>> driver can block the invalid filters of which related devices no longer
>> exist in the system.
>>
>> Signed-off-by: Yicong Yang <yangyicong@xxxxxxxxxxxxx>
>> ---
>
> Just a few trivial comments on this.
>
> With those tidied up
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Thanks for the comment, will fix in next version.
>
>
>
> ...
>
>> diff --git a/drivers/hwtracing/ptt/hisi_ptt.c b/drivers/hwtracing/ptt/hisi_ptt.c
>> index 0a10c7ec46ad..010cdbc3c172 100644
>> --- a/drivers/hwtracing/ptt/hisi_ptt.c
>> +++ b/drivers/hwtracing/ptt/hisi_ptt.c
>
>> +/*
>> + * A PCI bus notifier is used here for dynamically updating the filter
>> + * list.
>> + */
>> +static int hisi_ptt_notifier_call(struct notifier_block *nb, unsigned long action,
>> + void *data)
>> +{
>> + struct hisi_ptt *hisi_ptt = container_of(nb, struct hisi_ptt, hisi_ptt_nb);
>> + struct hisi_ptt_filter_update_info info;
>> + struct device *dev = data;
>> + struct pci_dev *pdev = to_pci_dev(dev);
>
> This local variable doesn't add anything over
>
> info.pdev = to_pci_dev(dev);
>
ok, will drop it.
>
>
>> +
>> + info.pdev = pdev;
>> +
>> + switch (action) {
>> + case BUS_NOTIFY_ADD_DEVICE:
>> + info.is_add = true;
>> + break;
>> + case BUS_NOTIFY_DEL_DEVICE:
>> + info.is_add = false;
>> + break;
>> + default:
>> + return 0;
>> + }
>> +
>> + hisi_ptt_update_fifo_in(hisi_ptt, &info);
>> +
>> + return 0;
>> +}
>> +
>
>> diff --git a/drivers/hwtracing/ptt/hisi_ptt.h b/drivers/hwtracing/ptt/hisi_ptt.h
>> index 5beb1648c93a..b1ba638fe7ea 100644
>> --- a/drivers/hwtracing/ptt/hisi_ptt.h
>> +++ b/drivers/hwtracing/ptt/hisi_ptt.h
>> @@ -11,12 +11,15 @@
>
>> /**
>> * struct hisi_ptt_pmu_buf - Descriptor of the AUX buffer of PTT trace
>> * @length: size of the AUX buffer
>> @@ -170,10 +188,15 @@ struct hisi_ptt_pmu_buf {
>> * @lower_bdf: the lower BDF range of the PCI devices managed by this PTT device
>> * @port_filters: the filter list of root ports
>> * @req_filters: the filter list of requester ID
>> + * @filter_lock: lock to protect the filters
>> * @port_mask: port mask of the managed root ports
>> + * @work: delayed work for filter updating
>> + * @filter_update_lock: spinlock to protect the filter update fifo
>> + * @filter_update_fifo: fifo of the filters waiting to update the filter list
>> */
>> struct hisi_ptt {
>> struct hisi_ptt_trace_ctrl trace_ctrl;
>> + struct notifier_block hisi_ptt_nb;
>
> Docs update for this one?
>
sorry for missing this. will fix.
Thanks,
Yicong
>> struct hlist_node hotplug_node;
>> struct pmu hisi_ptt_pmu;
>> void __iomem *iobase;
>> @@ -192,7 +215,19 @@ struct hisi_ptt {
>> */
>> struct list_head port_filters;
>> struct list_head req_filters;
>> + struct mutex filter_lock;
>> u16 port_mask;
>> +
>> + /*
>> + * We use a delayed work here to avoid indefinitely waiting for
>> + * the hisi_ptt->mutex which protecting the filter list. The
>> + * work will be delayed only if the mutex can not be held,
>> + * otherwise no delay will be applied.
>> + */
>> + struct delayed_work work;
>> + spinlock_t filter_update_lock;
>> + DECLARE_KFIFO(filter_update_kfifo, struct hisi_ptt_filter_update_info,
>> + HISI_PTT_FILTER_UPDATE_FIFO_SIZE);
>> };
>>
>> #define to_hisi_ptt(pmu) container_of(pmu, struct hisi_ptt, hisi_ptt_pmu)
>
> .
>
