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Commit 3c97f5de authored by Rajkumar Manoharan's avatar Rajkumar Manoharan Committed by Kalle Valo
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ath10k: implement NAPI support 



Add NAPI support for rx and tx completion. NAPI poll is scheduled
from interrupt handler. The design is as below

 - on interrupt
     - schedule napi and mask interrupts
 - on poll
   - process all pipes (no actual Tx/Rx)
   - process Rx within budget
   - if quota exceeds budget reschedule napi poll by returning budget
   - process Tx completions and update budget if necessary
   - process Tx fetch indications (pull-push)
   - push any other pending Tx (if possible)
   - before resched or napi completion replenish htt rx ring buffer
   - if work done < budget, complete napi poll and unmask interrupts

This change also get rid of two tasklets (intr_tq and txrx_compl_task).

Measured peak throughput with NAPI on IPQ4019 platform in controlled
environment. No noticeable reduction in throughput is seen and also
observed improvements in CPU usage. Approx. 15% CPU usage got reduced
in UDP uplink case.

DL: AP DUT Tx
UL: AP DUT Rx

IPQ4019 (avg. cpu usage %)

========
                TOT              +NAPI
              ===========      =============
TCP DL       644 Mbps (42%)    645 Mbps (36%)
TCP UL       673 Mbps (30%)    675 Mbps (26%)
UDP DL       682 Mbps (49%)    680 Mbps (49%)
UDP UL       720 Mbps (28%)    717 Mbps (11%)

Signed-off-by: default avatarRajkumar Manoharan <rmanohar@qti.qualcomm.com>
Signed-off-by: default avatarKalle Valo <kvalo@qca.qualcomm.com>
parent c39265f7

drivers/net/wireless/ath/ath10k/ahb.c

+7 −3
Original line number Diff line number Diff line
@@ -462,13 +462,13 @@ static void ath10k_ahb_halt_chip(struct ath10k *ar) 
static irqreturn_t ath10k_ahb_interrupt_handler(int irq, void *arg)

{

	struct ath10k *ar = arg;

	struct ath10k_pci *ar_pci = ath10k_pci_priv(ar);



	if (!ath10k_pci_irq_pending(ar))

		return IRQ_NONE;



	ath10k_pci_disable_and_clear_legacy_irq(ar);

	tasklet_schedule(&ar_pci->intr_tq);

	ath10k_pci_irq_msi_fw_mask(ar);

	napi_schedule(&ar->napi);



	return IRQ_HANDLED;

}
@@ -717,6 +717,9 @@ static void ath10k_ahb_hif_stop(struct ath10k *ar) 
	synchronize_irq(ar_ahb->irq);



	ath10k_pci_flush(ar);



	napi_synchronize(&ar->napi);

	napi_disable(&ar->napi);

}



static int ath10k_ahb_hif_power_up(struct ath10k *ar)
@@ -748,6 +751,7 @@ static int ath10k_ahb_hif_power_up(struct ath10k *ar) 
		ath10k_err(ar, "could not wake up target CPU: %d\n", ret);

		goto err_ce_deinit;

	}

	napi_enable(&ar->napi);



	return 0;
@@ -831,7 +835,7 @@ static int ath10k_ahb_probe(struct platform_device *pdev) 
		goto err_resource_deinit;

	}



	ath10k_pci_init_irq_tasklets(ar);

	ath10k_pci_init_napi(ar);



	ret = ath10k_ahb_request_irq_legacy(ar);

	if (ret)

drivers/net/wireless/ath/ath10k/core.c

+2 −0
Original line number Diff line number Diff line
@@ -2322,6 +2322,8 @@ struct ath10k *ath10k_core_create(size_t priv_size, struct device *dev, 
	INIT_WORK(&ar->register_work, ath10k_core_register_work);

	INIT_WORK(&ar->restart_work, ath10k_core_restart);



	init_dummy_netdev(&ar->napi_dev);



	ret = ath10k_debug_create(ar);

	if (ret)

		goto err_free_aux_wq;

drivers/net/wireless/ath/ath10k/core.h

+8 −0
Original line number Diff line number Diff line
@@ -65,6 +65,10 @@ 
#define ATH10K_KEEPALIVE_MAX_IDLE 3895

#define ATH10K_KEEPALIVE_MAX_UNRESPONSIVE 3900



/* NAPI poll budget */

#define ATH10K_NAPI_BUDGET      64

#define ATH10K_NAPI_QUOTA_LIMIT 60



struct ath10k;



enum ath10k_bus {
@@ -954,6 +958,10 @@ struct ath10k { 
	struct ath10k_thermal thermal;

	struct ath10k_wow wow;



	/* NAPI */

	struct net_device napi_dev;

	struct napi_struct napi;



	/* must be last */

	u8 drv_priv[0] __aligned(sizeof(void *));

};

drivers/net/wireless/ath/ath10k/htt.h

+1 −1
Original line number Diff line number Diff line
@@ -1665,7 +1665,6 @@ struct ath10k_htt { 


	/* This is used to group tx/rx completions separately and process them

	 * in batches to reduce cache stalls */

	struct tasklet_struct txrx_compl_task;

	struct sk_buff_head rx_compl_q;

	struct sk_buff_head rx_in_ord_compl_q;

	struct sk_buff_head tx_fetch_ind_q;
@@ -1798,5 +1797,6 @@ int ath10k_htt_tx(struct ath10k_htt *htt, 
		  struct sk_buff *msdu);

void ath10k_htt_rx_pktlog_completion_handler(struct ath10k *ar,

					     struct sk_buff *skb);

int ath10k_htt_txrx_compl_task(struct ath10k *ar, int budget);



#endif

drivers/net/wireless/ath/ath10k/htt_rx.c

+94 −60
Original line number Diff line number Diff line
@@ -34,7 +34,6 @@ 
#define HTT_RX_RING_REFILL_RESCHED_MS 5



static int ath10k_htt_rx_get_csum_state(struct sk_buff *skb);

static void ath10k_htt_txrx_compl_task(unsigned long ptr);



static struct sk_buff *

ath10k_htt_rx_find_skb_paddr(struct ath10k *ar, u32 paddr)
@@ -226,7 +225,6 @@ int ath10k_htt_rx_ring_refill(struct ath10k *ar) 
void ath10k_htt_rx_free(struct ath10k_htt *htt)

{

	del_timer_sync(&htt->rx_ring.refill_retry_timer);

	tasklet_kill(&htt->txrx_compl_task);



	skb_queue_purge(&htt->rx_compl_q);

	skb_queue_purge(&htt->rx_in_ord_compl_q);
@@ -520,9 +518,6 @@ int ath10k_htt_rx_alloc(struct ath10k_htt *htt) 
	skb_queue_head_init(&htt->tx_fetch_ind_q);

	atomic_set(&htt->num_mpdus_ready, 0);



	tasklet_init(&htt->txrx_compl_task, ath10k_htt_txrx_compl_task,

		     (unsigned long)htt);



	ath10k_dbg(ar, ATH10K_DBG_BOOT, "htt rx ring size %d fill_level %d\n",

		   htt->rx_ring.size, htt->rx_ring.fill_level);

	return 0;
@@ -958,7 +953,7 @@ static void ath10k_process_rx(struct ath10k *ar, 
	trace_ath10k_rx_hdr(ar, skb->data, skb->len);

	trace_ath10k_rx_payload(ar, skb->data, skb->len);



	ieee80211_rx(ar->hw, skb);

	ieee80211_rx_napi(ar->hw, NULL, skb, &ar->napi);

}



static int ath10k_htt_rx_nwifi_hdrlen(struct ath10k *ar,
@@ -1527,7 +1522,7 @@ static int ath10k_htt_rx_handle_amsdu(struct ath10k_htt *htt) 
	struct ath10k *ar = htt->ar;

	static struct ieee80211_rx_status rx_status;

	struct sk_buff_head amsdu;

	int ret;

	int ret, num_msdus;



	__skb_queue_head_init(&amsdu);
@@ -1549,13 +1544,14 @@ static int ath10k_htt_rx_handle_amsdu(struct ath10k_htt *htt) 
		return ret;

	}



	num_msdus = skb_queue_len(&amsdu);

	ath10k_htt_rx_h_ppdu(ar, &amsdu, &rx_status, 0xffff);

	ath10k_htt_rx_h_unchain(ar, &amsdu, ret > 0);

	ath10k_htt_rx_h_filter(ar, &amsdu, &rx_status);

	ath10k_htt_rx_h_mpdu(ar, &amsdu, &rx_status);

	ath10k_htt_rx_h_deliver(ar, &amsdu, &rx_status);



	return 0;

	return num_msdus;

}



static void ath10k_htt_rx_proc_rx_ind(struct ath10k_htt *htt,
@@ -1579,15 +1575,6 @@ static void ath10k_htt_rx_proc_rx_ind(struct ath10k_htt *htt, 
		mpdu_count += mpdu_ranges[i].mpdu_count;



	atomic_add(mpdu_count, &htt->num_mpdus_ready);



	tasklet_schedule(&htt->txrx_compl_task);

}



static void ath10k_htt_rx_frag_handler(struct ath10k_htt *htt)

{

	atomic_inc(&htt->num_mpdus_ready);



	tasklet_schedule(&htt->txrx_compl_task);

}



static void ath10k_htt_rx_tx_compl_ind(struct ath10k *ar,
@@ -1772,7 +1759,7 @@ static void ath10k_htt_rx_h_rx_offload_prot(struct ieee80211_rx_status *status, 
			RX_FLAG_MMIC_STRIPPED;

}



static void ath10k_htt_rx_h_rx_offload(struct ath10k *ar,

static int ath10k_htt_rx_h_rx_offload(struct ath10k *ar,

				      struct sk_buff_head *list)

{

	struct ath10k_htt *htt = &ar->htt;
@@ -1780,6 +1767,7 @@ static void ath10k_htt_rx_h_rx_offload(struct ath10k *ar, 
	struct htt_rx_offload_msdu *rx;

	struct sk_buff *msdu;

	size_t offset;

	int num_msdu = 0;



	while ((msdu = __skb_dequeue(list))) {

		/* Offloaded frames don't have Rx descriptor. Instead they have
@@ -1819,10 +1807,12 @@ static void ath10k_htt_rx_h_rx_offload(struct ath10k *ar, 
		ath10k_htt_rx_h_rx_offload_prot(status, msdu);

		ath10k_htt_rx_h_channel(ar, status, NULL, rx->vdev_id);

		ath10k_process_rx(ar, status, msdu);

		num_msdu++;

	}

	return num_msdu;

}



static void ath10k_htt_rx_in_ord_ind(struct ath10k *ar, struct sk_buff *skb)

static int ath10k_htt_rx_in_ord_ind(struct ath10k *ar, struct sk_buff *skb)

{

	struct ath10k_htt *htt = &ar->htt;

	struct htt_resp *resp = (void *)skb->data;
@@ -1835,12 +1825,12 @@ static void ath10k_htt_rx_in_ord_ind(struct ath10k *ar, struct sk_buff *skb) 
	u8 tid;

	bool offload;

	bool frag;

	int ret;

	int ret, num_msdus = 0;



	lockdep_assert_held(&htt->rx_ring.lock);



	if (htt->rx_confused)

		return;

		return -EIO;



	skb_pull(skb, sizeof(resp->hdr));

	skb_pull(skb, sizeof(resp->rx_in_ord_ind));
@@ -1859,7 +1849,7 @@ static void ath10k_htt_rx_in_ord_ind(struct ath10k *ar, struct sk_buff *skb) 


	if (skb->len < msdu_count * sizeof(*resp->rx_in_ord_ind.msdu_descs)) {

		ath10k_warn(ar, "dropping invalid in order rx indication\n");

		return;

		return -EINVAL;

	}



	/* The event can deliver more than 1 A-MSDU. Each A-MSDU is later
@@ -1870,14 +1860,14 @@ static void ath10k_htt_rx_in_ord_ind(struct ath10k *ar, struct sk_buff *skb) 
	if (ret < 0) {

		ath10k_warn(ar, "failed to pop paddr list: %d\n", ret);

		htt->rx_confused = true;

		return;

		return -EIO;

	}



	/* Offloaded frames are very different and need to be handled

	 * separately.

	 */

	if (offload)

		ath10k_htt_rx_h_rx_offload(ar, &list);

		num_msdus = ath10k_htt_rx_h_rx_offload(ar, &list);



	while (!skb_queue_empty(&list)) {

		__skb_queue_head_init(&amsdu);
@@ -1890,6 +1880,7 @@ static void ath10k_htt_rx_in_ord_ind(struct ath10k *ar, struct sk_buff *skb) 
			 * better to report something than nothing though. This

			 * should still give an idea about rx rate to the user.

			 */

			num_msdus += skb_queue_len(&amsdu);

			ath10k_htt_rx_h_ppdu(ar, &amsdu, status, vdev_id);

			ath10k_htt_rx_h_filter(ar, &amsdu, status);

			ath10k_htt_rx_h_mpdu(ar, &amsdu, status);
@@ -1902,9 +1893,10 @@ static void ath10k_htt_rx_in_ord_ind(struct ath10k *ar, struct sk_buff *skb) 
			ath10k_warn(ar, "failed to extract amsdu: %d\n", ret);

			htt->rx_confused = true;

			__skb_queue_purge(&list);

			return;

			return -EIO;

		}

	}

	return num_msdus;

}



static void ath10k_htt_rx_tx_fetch_resp_id_confirm(struct ath10k *ar,
@@ -2267,7 +2259,6 @@ bool ath10k_htt_t2h_msg_handler(struct ath10k *ar, struct sk_buff *skb) 
	}

	case HTT_T2H_MSG_TYPE_TX_COMPL_IND:

		ath10k_htt_rx_tx_compl_ind(htt->ar, skb);

		tasklet_schedule(&htt->txrx_compl_task);

		break;

	case HTT_T2H_MSG_TYPE_SEC_IND: {

		struct ath10k *ar = htt->ar;
@@ -2284,7 +2275,7 @@ bool ath10k_htt_t2h_msg_handler(struct ath10k *ar, struct sk_buff *skb) 
	case HTT_T2H_MSG_TYPE_RX_FRAG_IND: {

		ath10k_dbg_dump(ar, ATH10K_DBG_HTT_DUMP, NULL, "htt event: ",

				skb->data, skb->len);

		ath10k_htt_rx_frag_handler(htt);

		atomic_inc(&htt->num_mpdus_ready);

		break;

	}

	case HTT_T2H_MSG_TYPE_TEST:
@@ -2320,8 +2311,7 @@ bool ath10k_htt_t2h_msg_handler(struct ath10k *ar, struct sk_buff *skb) 
		break;

	}

	case HTT_T2H_MSG_TYPE_RX_IN_ORD_PADDR_IND: {

		skb_queue_tail(&htt->rx_in_ord_compl_q, skb);

		tasklet_schedule(&htt->txrx_compl_task);

		__skb_queue_tail(&htt->rx_in_ord_compl_q, skb);

		return false;

	}

	case HTT_T2H_MSG_TYPE_TX_CREDIT_UPDATE_IND:
@@ -2347,7 +2337,6 @@ bool ath10k_htt_t2h_msg_handler(struct ath10k *ar, struct sk_buff *skb) 
			break;

		}

		skb_queue_tail(&htt->tx_fetch_ind_q, tx_fetch_ind);

		tasklet_schedule(&htt->txrx_compl_task);

		break;

	}

	case HTT_T2H_MSG_TYPE_TX_FETCH_CONFIRM:
@@ -2376,27 +2365,77 @@ void ath10k_htt_rx_pktlog_completion_handler(struct ath10k *ar, 
}

EXPORT_SYMBOL(ath10k_htt_rx_pktlog_completion_handler);



static void ath10k_htt_txrx_compl_task(unsigned long ptr)

int ath10k_htt_txrx_compl_task(struct ath10k *ar, int budget)

{

	struct ath10k_htt *htt = (struct ath10k_htt *)ptr;

	struct ath10k *ar = htt->ar;

	struct ath10k_htt *htt = &ar->htt;

	struct htt_tx_done tx_done = {};

	struct sk_buff_head rx_ind_q;

	struct sk_buff_head tx_ind_q;

	struct sk_buff *skb;

	unsigned long flags;

	int num_mpdus;

	int quota = 0, done, num_rx_msdus;

	bool resched_napi = false;



	__skb_queue_head_init(&rx_ind_q);

	__skb_queue_head_init(&tx_ind_q);



	spin_lock_irqsave(&htt->rx_in_ord_compl_q.lock, flags);

	skb_queue_splice_init(&htt->rx_in_ord_compl_q, &rx_ind_q);

	spin_unlock_irqrestore(&htt->rx_in_ord_compl_q.lock, flags);

	/* Since in-ord-ind can deliver more than 1 A-MSDU in single event,

	 * process it first to utilize full available quota.

	 */

	while (quota < budget) {

		if (skb_queue_empty(&htt->rx_in_ord_compl_q))

			break;



	spin_lock_irqsave(&htt->tx_fetch_ind_q.lock, flags);

	skb_queue_splice_init(&htt->tx_fetch_ind_q, &tx_ind_q);

	spin_unlock_irqrestore(&htt->tx_fetch_ind_q.lock, flags);

		skb = __skb_dequeue(&htt->rx_in_ord_compl_q);

		if (!skb) {

			resched_napi = true;

			goto exit;

		}



		spin_lock_bh(&htt->rx_ring.lock);

		num_rx_msdus = ath10k_htt_rx_in_ord_ind(ar, skb);

		spin_unlock_bh(&htt->rx_ring.lock);

		if (num_rx_msdus < 0) {

			resched_napi = true;

			goto exit;

		}



		dev_kfree_skb_any(skb);

		if (num_rx_msdus > 0)

			quota += num_rx_msdus;



		if ((quota > ATH10K_NAPI_QUOTA_LIMIT) &&

		    !skb_queue_empty(&htt->rx_in_ord_compl_q)) {

			resched_napi = true;

			goto exit;

		}

	}



	while (quota < budget) {

		/* no more data to receive */

		if (!atomic_read(&htt->num_mpdus_ready))

			break;



		num_rx_msdus = ath10k_htt_rx_handle_amsdu(htt);

		if (num_rx_msdus < 0) {

			resched_napi = true;

			goto exit;

		}



		quota += num_rx_msdus;

		atomic_dec(&htt->num_mpdus_ready);

		if ((quota > ATH10K_NAPI_QUOTA_LIMIT) &&

		    atomic_read(&htt->num_mpdus_ready)) {

			resched_napi = true;

			goto exit;

		}

	}



	/* From NAPI documentation:

	 *  The napi poll() function may also process TX completions, in which

	 *  case if it processes the entire TX ring then it should count that

	 *  work as the rest of the budget.

	 */

	if ((quota < budget) && !kfifo_is_empty(&htt->txdone_fifo))

		quota = budget;



	/* kfifo_get: called only within txrx_tasklet so it's neatly serialized.

	 * From kfifo_get() documentation:
@@ -2406,27 +2445,22 @@ static void ath10k_htt_txrx_compl_task(unsigned long ptr) 
	while (kfifo_get(&htt->txdone_fifo, &tx_done))

		ath10k_txrx_tx_unref(htt, &tx_done);



	spin_lock_irqsave(&htt->tx_fetch_ind_q.lock, flags);

	skb_queue_splice_init(&htt->tx_fetch_ind_q, &tx_ind_q);

	spin_unlock_irqrestore(&htt->tx_fetch_ind_q.lock, flags);



	while ((skb = __skb_dequeue(&tx_ind_q))) {

		ath10k_htt_rx_tx_fetch_ind(ar, skb);

		dev_kfree_skb_any(skb);

	}



	num_mpdus = atomic_read(&htt->num_mpdus_ready);



	while (num_mpdus) {

		if (ath10k_htt_rx_handle_amsdu(htt))

			break;



		num_mpdus--;

		atomic_dec(&htt->num_mpdus_ready);

	}



	while ((skb = __skb_dequeue(&rx_ind_q))) {

		spin_lock_bh(&htt->rx_ring.lock);

		ath10k_htt_rx_in_ord_ind(ar, skb);

		spin_unlock_bh(&htt->rx_ring.lock);

		dev_kfree_skb_any(skb);

	}



exit:

	ath10k_htt_rx_msdu_buff_replenish(htt);

	/* In case of rx failure or more data to read, report budget

	 * to reschedule NAPI poll

	 */

	done = resched_napi ? budget : quota;



	return done;

}

EXPORT_SYMBOL(ath10k_htt_txrx_compl_task);