From: Jakub Kicinski <jakub.kicinski@netronome.com>
Date: Mon, 15 May 2017 17:55:22 -0700
Subject: nfp: add a helper for wrapping descriptor index
Patch-mainline: v4.13-rc1
Git-commit: 4aa3b7660aa79bb030aaa887dc16a60e02fa4348
References: bsc#1055968
We have a number of places where we calculate the descriptor
index based on a value which may have overflown. Create a
macro for masking with the ring size.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/net/ethernet/netronome/nfp/nfp_net.h | 3 ++
drivers/net/ethernet/netronome/nfp/nfp_net_common.c | 21 +++++++++-----------
2 files changed, 13 insertions(+), 11 deletions(-)
--- a/drivers/net/ethernet/netronome/nfp/nfp_net.h
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net.h
@@ -117,6 +117,9 @@ struct nfp_eth_table_port;
struct nfp_net;
struct nfp_net_r_vector;
+/* Convenience macro for wrapping descriptor index on ring size */
+#define D_IDX(ring, idx) ((idx) & ((ring)->cnt - 1))
+
/* Convenience macro for writing dma address into RX/TX descriptors */
#define nfp_desc_set_dma_addr(desc, dma_addr) \
do { \
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -809,7 +809,7 @@ static int nfp_net_tx(struct sk_buff *sk
if (dma_mapping_error(dp->dev, dma_addr))
goto err_free;
- wr_idx = tx_ring->wr_p & (tx_ring->cnt - 1);
+ wr_idx = D_IDX(tx_ring, tx_ring->wr_p);
/* Stash the soft descriptor of the head then initialize it */
txbuf = &tx_ring->txbufs[wr_idx];
@@ -852,7 +852,7 @@ static int nfp_net_tx(struct sk_buff *sk
if (dma_mapping_error(dp->dev, dma_addr))
goto err_unmap;
- wr_idx = (wr_idx + 1) & (tx_ring->cnt - 1);
+ wr_idx = D_IDX(tx_ring, wr_idx + 1);
tx_ring->txbufs[wr_idx].skb = skb;
tx_ring->txbufs[wr_idx].dma_addr = dma_addr;
tx_ring->txbufs[wr_idx].fidx = f;
@@ -945,8 +945,7 @@ static void nfp_net_tx_complete(struct n
todo = qcp_rd_p + tx_ring->cnt - tx_ring->qcp_rd_p;
while (todo--) {
- idx = tx_ring->rd_p & (tx_ring->cnt - 1);
- tx_ring->rd_p++;
+ idx = D_IDX(tx_ring, tx_ring->rd_p++);
skb = tx_ring->txbufs[idx].skb;
if (!skb)
@@ -1022,11 +1021,11 @@ static bool nfp_net_xdp_complete(struct
done_all = todo <= NFP_NET_XDP_MAX_COMPLETE;
todo = min(todo, NFP_NET_XDP_MAX_COMPLETE);
- tx_ring->qcp_rd_p = (tx_ring->qcp_rd_p + todo) & (tx_ring->cnt - 1);
+ tx_ring->qcp_rd_p = D_IDX(tx_ring, tx_ring->qcp_rd_p + todo);
done_pkts = todo;
while (todo--) {
- idx = tx_ring->rd_p & (tx_ring->cnt - 1);
+ idx = D_IDX(tx_ring, tx_ring->rd_p);
tx_ring->rd_p++;
done_bytes += tx_ring->txbufs[idx].real_len;
@@ -1062,7 +1061,7 @@ nfp_net_tx_ring_reset(struct nfp_net_dp
struct sk_buff *skb;
int idx, nr_frags;
- idx = tx_ring->rd_p & (tx_ring->cnt - 1);
+ idx = D_IDX(tx_ring, tx_ring->rd_p);
tx_buf = &tx_ring->txbufs[idx];
skb = tx_ring->txbufs[idx].skb;
@@ -1215,7 +1214,7 @@ static void nfp_net_rx_give_one(const st
{
unsigned int wr_idx;
- wr_idx = rx_ring->wr_p & (rx_ring->cnt - 1);
+ wr_idx = D_IDX(rx_ring, rx_ring->wr_p);
nfp_net_dma_sync_dev_rx(dp, dma_addr);
@@ -1253,7 +1252,7 @@ static void nfp_net_rx_ring_reset(struct
unsigned int wr_idx, last_idx;
/* Move the empty entry to the end of the list */
- wr_idx = rx_ring->wr_p & (rx_ring->cnt - 1);
+ wr_idx = D_IDX(rx_ring, rx_ring->wr_p);
last_idx = rx_ring->cnt - 1;
rx_ring->rxbufs[wr_idx].dma_addr = rx_ring->rxbufs[last_idx].dma_addr;
rx_ring->rxbufs[wr_idx].frag = rx_ring->rxbufs[last_idx].frag;
@@ -1521,7 +1520,7 @@ nfp_net_tx_xdp_buf(struct nfp_net_dp *dp
}
}
- wr_idx = tx_ring->wr_p & (tx_ring->cnt - 1);
+ wr_idx = D_IDX(tx_ring, tx_ring->wr_p);
/* Stash the soft descriptor of the head then initialize it */
txbuf = &tx_ring->txbufs[wr_idx];
@@ -1609,7 +1608,7 @@ static int nfp_net_rx(struct nfp_net_rx_
dma_addr_t new_dma_addr;
void *new_frag;
- idx = rx_ring->rd_p & (rx_ring->cnt - 1);
+ idx = D_IDX(rx_ring, rx_ring->rd_p);
rxd = &rx_ring->rxds[idx];
if (!(rxd->rxd.meta_len_dd & PCIE_DESC_RX_DD))