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

[Dexuan Cui <decui@microsoft.com>]

> From: linux-hyperv-owner@vger.kernel.org
> 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