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authorDoug Berger <opendmb@gmail.com>2017-03-13 17:41:33 -0700
committerDavid S. Miller <davem@davemloft.net>2017-03-13 21:51:49 -0700
commitc298ede2fe21e034ab6ba4f15340fadc03ae9663 (patch)
tree8201f36ecb488e401e01e8a3cdd52f1149aaa891 /drivers/net
parent83ee102a6998f808ac4c626e8f72344f0a355527 (diff)
downloadlinux-c298ede2fe21e034ab6ba4f15340fadc03ae9663.tar.bz2
net: bcmgenet: simplify circular pointer arithmetic
A 2's complement subtraction will always do a borrow, so masking off the sign bits is the same as conditionally adding (mask+1). Signed-off-by: Doug Berger <opendmb@gmail.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net')
-rw-r--r--drivers/net/ethernet/broadcom/genet/bcmgenet.c19
1 files changed, 5 insertions, 14 deletions
diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
index f92896835d2a..2c008b09c4e3 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
@@ -1,7 +1,7 @@
/*
* Broadcom GENET (Gigabit Ethernet) controller driver
*
- * Copyright (c) 2014 Broadcom Corporation
+ * Copyright (c) 2014-2017 Broadcom
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
@@ -1175,13 +1175,9 @@ static unsigned int __bcmgenet_tx_reclaim(struct net_device *dev,
unsigned int txbds_processed = 0;
/* Compute how many buffers are transmitted since last xmit call */
- c_index = bcmgenet_tdma_ring_readl(priv, ring->index, TDMA_CONS_INDEX);
- c_index &= DMA_C_INDEX_MASK;
-
- if (likely(c_index >= ring->c_index))
- txbds_ready = c_index - ring->c_index;
- else
- txbds_ready = (DMA_C_INDEX_MASK + 1) - ring->c_index + c_index;
+ c_index = bcmgenet_tdma_ring_readl(priv, ring->index, TDMA_CONS_INDEX)
+ & DMA_C_INDEX_MASK;
+ txbds_ready = (c_index - ring->c_index) & DMA_C_INDEX_MASK;
netif_dbg(priv, tx_done, dev,
"%s ring=%d old_c_index=%u c_index=%u txbds_ready=%u\n",
@@ -1611,12 +1607,7 @@ static unsigned int bcmgenet_desc_rx(struct bcmgenet_rx_ring *ring,
}
p_index &= DMA_P_INDEX_MASK;
-
- if (likely(p_index >= ring->c_index))
- rxpkttoprocess = p_index - ring->c_index;
- else
- rxpkttoprocess = (DMA_C_INDEX_MASK + 1) - ring->c_index +
- p_index;
+ rxpkttoprocess = (p_index - ring->c_index) & DMA_C_INDEX_MASK;
netif_dbg(priv, rx_status, dev,
"RDMA: rxpkttoprocess=%d\n", rxpkttoprocess);