Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 1aac1e91 authored by Arend van Spriel's avatar Arend van Spriel Committed by John W. Linville
Browse files

brcmfmac: add credit borrowing mechanism 



The firmware provides credits to the driver per WMM-AC. When
only AC_BE are to be transmitted to the firmware the driver
may use credits from other priorities to send AC_BE packets
towards the firmware.

Reviewed-by: default avatarHante Meuleman <meuleman@broadcom.com>
Reviewed-by: default avatarPieter-Paul Giesberts <pieterpg@broadcom.com>
Signed-off-by: default avatarArend van Spriel <arend@broadcom.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent a786b38d

drivers/net/wireless/brcm80211/brcmfmac/fwsignal.c

+87 −8
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 
#include <linux/netdevice.h>

#include <linux/etherdevice.h>

#include <linux/err.h>

#include <linux/jiffies.h>

#include <uapi/linux/nl80211.h>

#include <net/cfg80211.h>
@@ -271,6 +272,9 @@ struct brcmf_skbuff_cb { 
	brcmu_maskget32(txs, BRCMF_FWS_TXSTAT_ ## field ## _MASK, \

			BRCMF_FWS_TXSTAT_ ## field ## _SHIFT)



/* How long to defer borrowing in jiffies */

#define BRCMF_FWS_BORROW_DEFER_PERIOD		(HZ / 10)



/**

 * enum brcmf_fws_fifo - fifo indices used by dongle firmware.

 *
@@ -425,9 +429,11 @@ struct brcmf_fws_info { 
	struct work_struct fws_dequeue_work;

	u32 fifo_enqpkt[BRCMF_FWS_FIFO_COUNT];

	int fifo_credit[BRCMF_FWS_FIFO_COUNT];

	int credits_borrowed[BRCMF_FWS_FIFO_AC_VO + 1];

	int deq_node_pos[BRCMF_FWS_FIFO_COUNT];

	u32 fifo_credit_map;

	u32 fifo_delay_map;

	unsigned long borrow_defer_timestamp;

};



/*
@@ -997,9 +1003,34 @@ static int brcmf_fws_request_indicate(struct brcmf_fws_info *fws, u8 type, 
static void brcmf_fws_return_credits(struct brcmf_fws_info *fws,

				     u8 fifo, u8 credits)

{

	int lender_ac;

	int *borrowed;

	int *fifo_credit;



	if (!credits)

		return;



	if ((fifo == BRCMF_FWS_FIFO_AC_BE) &&

	    (fws->credits_borrowed[0])) {

		for (lender_ac = BRCMF_FWS_FIFO_AC_VO; lender_ac >= 0;

		     lender_ac--) {

			borrowed = &fws->credits_borrowed[lender_ac];

			if (*borrowed) {

				fws->fifo_credit_map |= (1 << lender_ac);

				fifo_credit = &fws->fifo_credit[lender_ac];

				if (*borrowed >= credits) {

					*borrowed -= credits;

					*fifo_credit += credits;

					return;

				} else {

					credits -= *borrowed;

					*fifo_credit += *borrowed;

					*borrowed = 0;

				}

			}

		}

	}



	fws->fifo_credit_map |= 1 << fifo;

	fws->fifo_credit[fifo] += credits;

}
@@ -1658,6 +1689,26 @@ brcmf_fws_rollback_toq(struct brcmf_fws_info *fws, struct sk_buff *skb) 
		fws->stats.rollback_success++;

}



static int brcmf_fws_borrow_credit(struct brcmf_fws_info *fws)

{

	int lender_ac;



	if (time_after(fws->borrow_defer_timestamp, jiffies))

		return -ENAVAIL;



	for (lender_ac = 0; lender_ac <= BRCMF_FWS_FIFO_AC_VO; lender_ac++) {

		if (fws->fifo_credit[lender_ac]) {

			fws->credits_borrowed[lender_ac]++;

			fws->fifo_credit[lender_ac]--;

			if (fws->fifo_credit[lender_ac] == 0)

				fws->fifo_credit_map &= ~(1 << lender_ac);

			brcmf_dbg(TRACE, "borrow credit from: %d\n", lender_ac);

			return 0;

		}

	}

	return -ENAVAIL;

}



static int brcmf_fws_consume_credit(struct brcmf_fws_info *fws, int fifo,

				    struct sk_buff *skb)

{
@@ -1691,8 +1742,17 @@ static int brcmf_fws_consume_credit(struct brcmf_fws_info *fws, int fifo, 
		return 0;

	}



	if (fifo != BRCMF_FWS_FIFO_AC_BE)

		fws->borrow_defer_timestamp = jiffies +

					      BRCMF_FWS_BORROW_DEFER_PERIOD;



	if (!(*credit)) {

		brcmf_dbg(TRACE, "exit: credits depleted\n");

		/* Try to borrow a credit from other queue */

		if (fifo == BRCMF_FWS_FIFO_AC_BE &&

		    brcmf_fws_borrow_credit(fws) == 0)

			return 0;



		brcmf_dbg(TRACE, "exit: ac=%d, credits depleted\n", fifo);

		return -ENAVAIL;

	}

	(*credit)--;
@@ -1741,6 +1801,7 @@ static int brcmf_fws_commit_skb(struct brcmf_fws_info *fws, int fifo, 
int brcmf_fws_process_skb(struct brcmf_if *ifp, struct sk_buff *skb)

{

	struct brcmf_pub *drvr = ifp->drvr;

	struct brcmf_fws_info *fws = drvr->fws;

	struct brcmf_skbuff_cb *skcb = brcmf_skbcb(skb);

	struct ethhdr *eh = (struct ethhdr *)(skb->data);

	ulong flags;
@@ -1755,7 +1816,7 @@ int brcmf_fws_process_skb(struct brcmf_if *ifp, struct sk_buff *skb) 
	if (ntohs(eh->h_proto) == ETH_P_PAE)

		atomic_inc(&ifp->pend_8021x_cnt);



	if (!brcmf_fws_fc_active(drvr->fws)) {

	if (!brcmf_fws_fc_active(fws)) {

		/* If the protocol uses a data header, apply it */

		brcmf_proto_hdrpush(drvr, ifp->ifidx, 0, skb);
@@ -1765,7 +1826,7 @@ int brcmf_fws_process_skb(struct brcmf_if *ifp, struct sk_buff *skb) 


	/* set control buffer information */

	skcb->if_flags = 0;

	skcb->mac = brcmf_fws_find_mac_desc(drvr->fws, ifp, eh->h_dest);

	skcb->mac = brcmf_fws_find_mac_desc(fws, ifp, eh->h_dest);

	skcb->state = BRCMF_FWS_SKBSTATE_NEW;

	brcmf_skb_if_flags_set_field(skb, INDEX, ifp->ifidx);

	if (!multicast)
@@ -1777,15 +1838,17 @@ int brcmf_fws_process_skb(struct brcmf_if *ifp, struct sk_buff *skb) 


	brcmf_fws_lock(drvr, flags);

	if (skcb->mac->suppressed ||

	    brcmf_fws_mac_desc_closed(drvr->fws, skcb->mac, fifo) ||

	    brcmf_fws_mac_desc_closed(fws, skcb->mac, fifo) ||

	    brcmu_pktq_mlen(&skcb->mac->psq, 3 << (fifo * 2)) ||

	    (!multicast &&

	     brcmf_fws_consume_credit(drvr->fws, fifo, skb) < 0)) {

	     brcmf_fws_consume_credit(fws, fifo, skb) < 0)) {

		/* enqueue the packet in delayQ */

		drvr->fws->fifo_delay_map |= 1 << fifo;

		brcmf_fws_enq(drvr->fws, BRCMF_FWS_SKBSTATE_DELAYED, fifo, skb);

		brcmf_fws_enq(fws, BRCMF_FWS_SKBSTATE_DELAYED, fifo, skb);

	} else {

		brcmf_fws_commit_skb(drvr->fws, fifo, skb);

		if (brcmf_fws_commit_skb(fws, fifo, skb))

			if (!multicast)

				brcmf_skb_pick_up_credit(fws, fifo, skb);

	}

	brcmf_fws_unlock(drvr, flags);

	return 0;
@@ -1858,8 +1921,24 @@ static void brcmf_fws_dequeue_worker(struct work_struct *worker) 
			    BRCMF_SKB_IF_FLAGS_CREDITCHECK_MASK)

				credit++;

		}

		if ((fifo == BRCMF_FWS_FIFO_AC_BE) &&

		    (credit == fws->fifo_credit[fifo])) {

			fws->fifo_credit[fifo] -= credit;

			while (brcmf_fws_borrow_credit(fws) == 0) {

				skb = brcmf_fws_deq(fws, fifo);

				if (!skb) {

					brcmf_fws_return_credits(fws, fifo, 1);

					break;

				}

				if (brcmf_fws_commit_skb(fws, fifo, skb)) {

					brcmf_fws_return_credits(fws, fifo, 1);

					break;

				}

			}

		} else {

			fws->fifo_credit[fifo] -= credit;

		}

	}

	brcmf_fws_unlock(fws->drvr, flags);

}