RE: [EXTERNAL] [PATCH 1/2] PCI: hv: decouple the func definition in hv_dr_state from VSP message

[Long Li]

>Subject: RE: [EXTERNAL] [PATCH 1/2] PCI: hv: decouple the func definition in
>hv_dr_state from VSP message
>
>> From: linux-hyperv-owner@xxxxxxxxxxxxxxx
>> Sent: Friday, November 22, 2019 5:57 PM ...
>> +struct hv_pcidev_description {
>> +	u16	v_id;	/* vendor ID */
>> +	u16	d_id;	/* device ID */
>> +	u8	rev;
>> +	u8	prog_intf;
>> +	u8	subclass;
>> +	u8	base_class;
>> +	u32	subsystem_id;
>> +	union win_slot_encoding win_slot;
>
>Change the spact to a TAB? :-)
>
>>  /**
>> - * hv_pci_devices_present() - Handles list of new children
>> + * hv_pci_start_relations_work() - Queue work to start device
>> + discovery
>>   * @hbus:	Root PCI bus, as understood by this driver
>> - * @relations:	Packet from host listing children
>> + * @dr:		The list of children returned from host
>>   *
>> - * This function is invoked whenever a new list of devices for
>> - * this bus appears.
>> + * Return:  0 on success, 1 on failure
>>   */
>
>Usually we return a negative value upon error, if possible.
>
>> -static void hv_pci_devices_present(struct hv_pcibus_device *hbus,
>> -				   struct pci_bus_relations *relations)
>> +static int hv_pci_start_relations_work(struct hv_pcibus_device *hbus,
>> +				       struct hv_dr_state *dr)
>>  {
>> -	struct hv_dr_state *dr;
>>  	struct hv_dr_work *dr_wrk;
>> -	unsigned long flags;
>>  	bool pending_dr;
>> +	unsigned long flags;
>>
>>  	dr_wrk = kzalloc(sizeof(*dr_wrk), GFP_NOWAIT);
>>  	if (!dr_wrk)
>> -		return;
>> -
>> -	dr = kzalloc(offsetof(struct hv_dr_state, func) +
>> -		     (sizeof(struct pci_function_description) *
>> -		      (relations->device_count)), GFP_NOWAIT);
>> -	if (!dr)  {
>> -		kfree(dr_wrk);
>> -		return;
>> -	}
>> +		return 1;
>
>How about "return -ENOMEM;" ?
>
>> @@ -3018,7 +3055,7 @@ static void hv_pci_bus_exit(struct hv_device
>*hdev)
>>  		struct pci_packet teardown_packet;
>>  		u8 buffer[sizeof(struct pci_message)];
>>  	} pkt;
>> -	struct pci_bus_relations relations;
>> +	struct hv_dr_state *dr;
>>  	struct hv_pci_compl comp_pkt;
>>  	int ret;
>>
>> @@ -3030,8 +3067,9 @@ static void hv_pci_bus_exit(struct hv_device
>*hdev)
>>  		return;
>>
>>  	/* Delete any children which might still exist. */
>> -	memset(&relations, 0, sizeof(relations));
>> -	hv_pci_devices_present(hbus, &relations);
>> +	dr = kzalloc(sizeof(*dr), GFP_ATOMIC);
>
>Here we are in a process context, so GFP_KERNEL is preferred.
>
>> +	if (dr && hv_pci_start_relations_work(hbus, dr))
>> +		kfree(dr);
>
>Thanks,
>-- Dexuan

Thanks! I will send v2 to address those comments.

Long