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Date:      Thu, 9 May 2013 16:57:02 +0000 (UTC)
From:      Luigi Rizzo <luigi@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r250413 - head/sys/dev/e1000
Message-ID:  <201305091657.r49Gv2GK049987@svn.freebsd.org>
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Author: luigi
Date: Thu May  9 16:57:02 2013
New Revision: 250413
URL: http://svnweb.freebsd.org/changeset/base/250413

Log:
  simplify the code to initialize the RDT while in netmap mode.

Modified:
  head/sys/dev/e1000/if_em.c
  head/sys/dev/e1000/if_lem.c

Modified: head/sys/dev/e1000/if_em.c
==============================================================================
--- head/sys/dev/e1000/if_em.c	Thu May  9 16:42:01 2013	(r250412)
+++ head/sys/dev/e1000/if_em.c	Thu May  9 16:57:02 2013	(r250413)
@@ -4333,6 +4333,8 @@ em_initialize_receive_unit(struct adapte
 
 	for (int i = 0; i < adapter->num_queues; i++, rxr++) {
 		/* Setup the Base and Length of the Rx Descriptor Ring */
+		u32 rdt = adapter->num_rx_desc - 1; /* default */
+
 		bus_addr = rxr->rxdma.dma_paddr;
 		E1000_WRITE_REG(hw, E1000_RDLEN(i),
 		    adapter->num_rx_desc * sizeof(struct e1000_rx_desc));
@@ -4344,18 +4346,11 @@ em_initialize_receive_unit(struct adapte
 		/*
 		 * an init() while a netmap client is active must
 		 * preserve the rx buffers passed to userspace.
-		 * In this driver it means we adjust RDT to
-		 * something different from na->num_rx_desc - 1.
 		 */
-		if (ifp->if_capenable & IFCAP_NETMAP) {
-			struct netmap_adapter *na = NA(adapter->ifp);
-			struct netmap_kring *kring = &na->rx_rings[i];
-			int t = na->num_rx_desc - 1 - kring->nr_hwavail;
-
-			E1000_WRITE_REG(hw, E1000_RDT(i), t);
-		} else
+		if (ifp->if_capenable & IFCAP_NETMAP)
+			rdt -= NA(adapter->ifp)->rx_rings[i].nr_hwavail;
 #endif /* DEV_NETMAP */
-		E1000_WRITE_REG(hw, E1000_RDT(i), adapter->num_rx_desc - 1);
+		E1000_WRITE_REG(hw, E1000_RDT(i), rdt);
 	}
 
 	/* Set PTHRESH for improved jumbo performance */

Modified: head/sys/dev/e1000/if_lem.c
==============================================================================
--- head/sys/dev/e1000/if_lem.c	Thu May  9 16:42:01 2013	(r250412)
+++ head/sys/dev/e1000/if_lem.c	Thu May  9 16:57:02 2013	(r250413)
@@ -3361,19 +3361,13 @@ lem_initialize_receive_unit(struct adapt
 	 * Tail Descriptor Pointers
 	 */
 	E1000_WRITE_REG(&adapter->hw, E1000_RDH(0), 0);
+	rctl = adapter->num_rx_desc - 1; /* default RDT value */
 #ifdef DEV_NETMAP
 	/* preserve buffers already made available to clients */
-	if (ifp->if_capenable & IFCAP_NETMAP) {
-		struct netmap_adapter *na = NA(adapter->ifp);
-		struct netmap_kring *kring = &na->rx_rings[0];
-		int t = na->num_rx_desc - 1 - kring->nr_hwavail;
-
-		if (t >= na->num_rx_desc)
-			t -= na->num_rx_desc;
-		E1000_WRITE_REG(&adapter->hw, E1000_RDT(0), t);
-	} else
+	if (ifp->if_capenable & IFCAP_NETMAP)
+		rctl -= NA(adapter->ifp)->rx_rings[0].nr_hwavail;
 #endif /* DEV_NETMAP */
-	E1000_WRITE_REG(&adapter->hw, E1000_RDT(0), adapter->num_rx_desc - 1);
+	E1000_WRITE_REG(&adapter->hw, E1000_RDT(0), rctl);
 
 	return;
 }

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