brcmfmac: add credit numbers updating support

The credit numbers are static and tunable per chip in firmware side.
However the credit number may be changed that is based on packet pool
length and will send BRCMF_E_FIFO_CREDIT_MAP event to notify host driver
updates the credit numbers during interface up.
The purpose of this patch is making host driver has ability of updating
the credit numbers when receiving the BRCMF_E_FIFO_CREDIT_MAP event.
Signed-off-by: Wright Feng <wright.feng@cypress.com>
Acked-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

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

@@ -511,6 +511,7 @@ 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 init_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;
@@ -1237,6 +1238,9 @@ static void brcmf_fws_return_credits(struct brcmf_fws_info *fws,
 	}
 
 	fws->fifo_credit[fifo] += credits;
+	if (fws->fifo_credit[fifo] > fws->init_fifo_credit[fifo])
+		fws->fifo_credit[fifo] = fws->init_fifo_credit[fifo];
+
 }
 
 static void brcmf_fws_schedule_deq(struct brcmf_fws_info *fws)
@@ -1595,19 +1599,21 @@ static int brcmf_fws_notify_credit_map(struct brcmf_if *ifp,
 		brcmf_err("event payload too small (%d)\n", e->datalen);
 		return -EINVAL;
 	}
-	if (fws->creditmap_received)
-		return 0;
 
 	fws->creditmap_received = true;
 
 	brcmf_dbg(TRACE, "enter: credits %pM\n", credits);
 	brcmf_fws_lock(fws);
 	for (i = 0; i < ARRAY_SIZE(fws->fifo_credit); i++) {
-		if (*credits)
+		fws->fifo_credit[i] += credits[i] - fws->init_fifo_credit[i];
+		fws->init_fifo_credit[i] = credits[i];
+		if (fws->fifo_credit[i] > 0)
 			fws->fifo_credit_map |= 1 << i;
 		else
 			fws->fifo_credit_map &= ~(1 << i);
-		fws->fifo_credit[i] = *credits++;
+		WARN_ONCE(fws->fifo_credit[i] < 0,
+			  "fifo_credit[%d] is negative(%d)\n", i,
+			  fws->fifo_credit[i]);
 	}
 	brcmf_fws_schedule_deq(fws);
 	brcmf_fws_unlock(fws);
@@ -2013,7 +2019,7 @@ static int brcmf_fws_borrow_credit(struct brcmf_fws_info *fws)
 	}
 
 	for (lender_ac = 0; lender_ac <= BRCMF_FWS_FIFO_AC_VO; lender_ac++) {
-		if (fws->fifo_credit[lender_ac]) {
+		if (fws->fifo_credit[lender_ac] > 0) {
 			fws->credits_borrowed[lender_ac]++;
 			fws->fifo_credit[lender_ac]--;
 			if (fws->fifo_credit[lender_ac] == 0)
@@ -2210,7 +2216,8 @@ static void brcmf_fws_dequeue_worker(struct work_struct *worker)
 			}
 			continue;
 		}
-		while ((fws->fifo_credit[fifo]) || ((!fws->bcmc_credit_check) &&
+		while ((fws->fifo_credit[fifo] > 0) ||
+		       ((!fws->bcmc_credit_check) &&
 			(fifo == BRCMF_FWS_FIFO_BCMC))) {
 			skb = brcmf_fws_deq(fws, fifo);
 			if (!skb)
@@ -2222,7 +2229,7 @@ static void brcmf_fws_dequeue_worker(struct work_struct *worker)
 				break;
 		}
 		if ((fifo == BRCMF_FWS_FIFO_AC_BE) &&
-		    (fws->fifo_credit[fifo] == 0) &&
+		    (fws->fifo_credit[fifo] <= 0) &&
 		    (!fws->bus_flow_blocked)) {
 			while (brcmf_fws_borrow_credit(fws) == 0) {
 				skb = brcmf_fws_deq(fws, fifo);