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Commit ef6f001f authored by Maya Erez's avatar Maya Erez
Browse files

usb: gadget: optimize MBIM, RNDIS, ECM sys2bam data path to use skb pool 



This patch implement a gradually growing skb pool to optimize sys2bam
UL data path. This is required to ensure that whenever we queue a usb
request to the USB core we will have a free skb to attach its buffer
to the usb request, otherwise we may lose time performance.

Change-Id: I817c8df1ee4dbc3b6df68a9d307b6276341fd9cb
Signed-off-by: default avatarDanny Segal <dsegal@codeaurora.org>
Signed-off-by: default avatarMaya Erez <merez@codeaurora.org>
parent 602a0bb9

drivers/usb/gadget/u_bam_data.c

+78 −9
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ 


#define BAM2BAM_DATA_N_PORTS	1

#define BAM_DATA_RX_Q_SIZE	16

#define BAM_DATA_MUX_RX_REQ_SIZE  2048   /* Must be 1KB aligned */

#define BAM_DATA_PENDING_LIMIT	220



#define SYS_BAM_RX_PKT_FLOW_CTRL_SUPPORT	1
@@ -49,6 +50,8 @@ static int n_bam2bam_data_ports; 
unsigned int bam_data_rx_q_size = BAM_DATA_RX_Q_SIZE;

module_param(bam_data_rx_q_size, uint, S_IRUGO | S_IWUSR);



static unsigned int bam_data_mux_rx_req_size = BAM_DATA_MUX_RX_REQ_SIZE;

module_param(bam_data_mux_rx_req_size, uint, S_IRUGO | S_IWUSR);



#define SPS_PARAMS_SPS_MODE		BIT(5)

#define SPS_PARAMS_TBE		        BIT(6)
@@ -92,6 +95,7 @@ struct bam_data_ch_info { 
	struct sys2ipa_sw_data	ul_params;

	struct list_head	rx_idle;

	struct sk_buff_head	rx_skb_q;

	struct sk_buff_head	rx_skb_idle;

	enum usb_bam_pipe_type	src_pipe_type;

	enum usb_bam_pipe_type	dst_pipe_type;

	unsigned int		pending_with_bam;
@@ -157,6 +161,65 @@ static int bam_data_alloc_requests(struct usb_ep *ep, struct list_head *head, 
	return 0;

}



/* This function should be called with port_lock_ul lock taken */

static struct sk_buff *bam_data_alloc_skb_from_pool(

	struct bam_data_port *port)

{

	struct bam_data_ch_info *d;

	struct sk_buff *skb;



	if (!port)

		return NULL;

	d = &port->data_ch;

	if (!d)

		return NULL;



	if (d->rx_skb_idle.qlen == 0) {

		/*

		 * In case skb idle pool is empty, we allow to allocate more

		 * skbs so we dynamically enlarge the pool size when needed.

		 * Therefore, in steady state this dynamic allocation will

		 * stop when the pool will arrive to its optimal size.

		 */

		pr_debug("%s: allocate skb\n", __func__);

		skb = alloc_skb(d->rx_buffer_size + BAM_MUX_HDR, GFP_ATOMIC);

		if (!skb) {

			pr_err("%s: alloc skb failed\n", __func__);

			goto alloc_exit;

		}

	} else {

		pr_debug("%s: pull skb from pool\n", __func__);

		skb = __skb_dequeue(&d->rx_skb_idle);

	}



alloc_exit:

	return skb;

}



static void bam_data_free_skb_to_pool(

	struct bam_data_port *port,

	struct sk_buff *skb)

{

	struct bam_data_ch_info *d;

	unsigned long flags;



	if (!port) {

		dev_kfree_skb_any(skb);

		return;

	}

	d = &port->data_ch;

	if (!d) {

		dev_kfree_skb_any(skb);

		return;

	}



	spin_lock_irqsave(&port->port_lock_ul, flags);

	skb->len = 0;

	skb_reset_tail_pointer(skb);

	__skb_queue_tail(&d->rx_skb_idle, skb);

	spin_unlock_irqrestore(&port->port_lock_ul, flags);

}



static void bam_data_write_done(void *p, struct sk_buff *skb)

{

	struct bam_data_port	*port = p;
@@ -166,7 +229,7 @@ static void bam_data_write_done(void *p, struct sk_buff *skb) 
	if (!skb)

		return;



	dev_kfree_skb_any(skb);

	bam_data_free_skb_to_pool(port, skb);



	spin_lock_irqsave(&port->port_lock_ul, flags);

	d->pending_with_bam--;
@@ -233,7 +296,7 @@ static void bam_data_start_rx(struct bam_data_port *port) 
			break;



		req = list_first_entry(&d->rx_idle, struct usb_request, list);

		skb = alloc_skb(d->rx_buffer_size + BAM_MUX_HDR, GFP_ATOMIC);

		skb = bam_data_alloc_skb_from_pool(port);

		if (!skb)

			break;

		skb_reserve(skb, BAM_MUX_HDR);
@@ -246,7 +309,10 @@ static void bam_data_start_rx(struct bam_data_port *port) 
		ret = usb_ep_queue(ep, req, GFP_ATOMIC);

		spin_lock_irqsave(&port->port_lock_ul, flags);

		if (ret) {

			dev_kfree_skb_any(skb);

			spin_unlock_irqrestore(&port->port_lock_ul, flags);

			bam_data_free_skb_to_pool(port, skb);

			spin_lock_irqsave(&port->port_lock_ul, flags);





			pr_err("%s: rx queue failed %d\n", __func__, ret);
@@ -280,14 +346,14 @@ static void bam_data_epout_complete(struct usb_ep *ep, struct usb_request *req) 
	case -ECONNRESET:

	case -ESHUTDOWN:

		/* cable disconnection */

		dev_kfree_skb_any(skb);

		bam_data_free_skb_to_pool(port, skb);

		req->buf = 0;

		usb_ep_free_request(ep, req);

		return;

	default:

		pr_err("%s: %s response error %d, %d/%d\n", __func__,

			ep->name, status, req->actual, req->length);

		dev_kfree_skb_any(skb);

		bam_data_free_skb_to_pool(port, skb);

		break;

	}
@@ -312,9 +378,9 @@ static void bam_data_epout_complete(struct usb_ep *ep, struct usb_request *req) 
		spin_unlock(&port->port_lock_ul);

		return;

	}

	spin_unlock(&port->port_lock_ul);



	skb = alloc_skb(d->rx_buffer_size + BAM_MUX_HDR, GFP_ATOMIC);

	skb = bam_data_alloc_skb_from_pool(port);

	spin_unlock(&port->port_lock_ul);

	if (!skb) {

		list_add_tail(&req->list, &d->rx_idle);

		return;
@@ -327,7 +393,7 @@ static void bam_data_epout_complete(struct usb_ep *ep, struct usb_request *req) 


	status = usb_ep_queue(ep, req, GFP_ATOMIC);

	if (status) {

		dev_kfree_skb_any(skb);

		bam_data_free_skb_to_pool(port, skb);



		pr_err("%s: data rx enqueue err %d\n", __func__, status);
@@ -401,7 +467,9 @@ static void bam_data_write_toipa(struct work_struct *w) 
		if (ret) {

			pr_debug("%s: write error:%d\n", __func__, ret);

			d->pending_with_bam--;

			dev_kfree_skb_any(skb);

			spin_unlock_irqrestore(&port->port_lock_ul, flags);

			bam_data_free_skb_to_pool(port, skb);

			spin_lock_irqsave(&port->port_lock_ul, flags);

			break;

		}

	}
@@ -932,6 +1000,7 @@ static int bam2bam_data_port_alloc(int portno) 


	/* UL workaround requirements */

	skb_queue_head_init(&d->rx_skb_q);

	skb_queue_head_init(&d->rx_skb_idle);

	INIT_LIST_HEAD(&d->rx_idle);

	INIT_WORK(&d->write_tobam_w, bam_data_write_toipa);