From 1aac1e91171586e4d0981e40484a7c93d9b1f289 Mon Sep 17 00:00:00 2001 From: Arend van Spriel Date: Tue, 23 Apr 2013 12:53:15 +0200 Subject: [PATCH] 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: Hante Meuleman Reviewed-by: Pieter-Paul Giesberts Signed-off-by: Arend van Spriel Signed-off-by: John W. Linville --- drivers/net/wireless/brcm80211/brcmfmac/fwsignal.c | 95 ++++++++++++++++++++-- 1 file changed, 87 insertions(+), 8 deletions(-) diff --git a/drivers/net/wireless/brcm80211/brcmfmac/fwsignal.c b/drivers/net/wireless/brcm80211/brcmfmac/fwsignal.c index f9153b1..5352dc1 100644 --- a/drivers/net/wireless/brcm80211/brcmfmac/fwsignal.c +++ b/drivers/net/wireless/brcm80211/brcmfmac/fwsignal.c @@ -21,6 +21,7 @@ #include #include #include +#include #include #include @@ -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 @@ fail: 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 @@ rollback: 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; @@ -1858,7 +1921,23 @@ static void brcmf_fws_dequeue_worker(struct work_struct *worker) BRCMF_SKB_IF_FLAGS_CREDITCHECK_MASK) credit++; } - fws->fifo_credit[fifo] -= 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); } -- 2.7.4