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nfp: make use of the DMA_ATTR_SKIP_CPU_SYNC attr

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DMA unmap may destroy changes CPU made to the buffer.  To make XDP
run correctly on non-x86 platforms we should use the
DMA_ATTR_SKIP_CPU_SYNC attribute.

Thanks to using the attribute we can now push the sync operation to the
common code path from XDP handler.

A little bit of variable name reshuffling is required to bring the
code back to readable state.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jakub Kicinski 2017-04-22 20:17:52 -07:00 committed by David S. Miller
parent 0d688a0d33
commit 5cd4fbeab2
1 changed files with 35 additions and 18 deletions
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53
drivers/net/ethernet/netronome/nfp/nfp_net_common.c
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@ -87,16 +87,31 @@ void nfp_net_get_fw_version(struct nfp_net_fw_version *fw_ver,
static dma_addr_t nfp_net_dma_map_rx(struct nfp_net_dp *dp, void *frag)
{
return dma_map_single(dp->dev, frag + NFP_NET_RX_BUF_HEADROOM,
dp->fl_bufsz - NFP_NET_RX_BUF_NON_DATA,
dp->rx_dma_dir);
return dma_map_single_attrs(dp->dev, frag + NFP_NET_RX_BUF_HEADROOM,
dp->fl_bufsz - NFP_NET_RX_BUF_NON_DATA,
dp->rx_dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
}
static void
nfp_net_dma_sync_dev_rx(const struct nfp_net_dp *dp, dma_addr_t dma_addr)
{
dma_sync_single_for_device(dp->dev, dma_addr,
dp->fl_bufsz - NFP_NET_RX_BUF_NON_DATA,
dp->rx_dma_dir);
}
static void nfp_net_dma_unmap_rx(struct nfp_net_dp *dp, dma_addr_t dma_addr)
{
dma_unmap_single(dp->dev, dma_addr,
dp->fl_bufsz - NFP_NET_RX_BUF_NON_DATA,
dp->rx_dma_dir);
dma_unmap_single_attrs(dp->dev, dma_addr,
dp->fl_bufsz - NFP_NET_RX_BUF_NON_DATA,
dp->rx_dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
}
static void nfp_net_dma_sync_cpu_rx(struct nfp_net_dp *dp, dma_addr_t dma_addr,
unsigned int len)
{
dma_sync_single_for_cpu(dp->dev, dma_addr - NFP_NET_RX_BUF_HEADROOM,
len, dp->rx_dma_dir);
}
/* Firmware reconfig
@ -1208,6 +1223,8 @@ static void nfp_net_rx_give_one(const struct nfp_net_dp *dp,
wr_idx = rx_ring->wr_p & (rx_ring->cnt - 1);
nfp_net_dma_sync_dev_rx(dp, dma_addr);
/* Stash SKB and DMA address away */
rx_ring->rxbufs[wr_idx].frag = frag;
rx_ring->rxbufs[wr_idx].dma_addr = dma_addr;
@ -1569,7 +1586,7 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget)
tx_ring = r_vec->xdp_ring;
while (pkts_polled < budget) {
unsigned int meta_len, data_len, data_off, pkt_len;
unsigned int meta_len, data_len, meta_off, pkt_len, pkt_off;
u8 meta_prepend[NFP_NET_MAX_PREPEND];
struct nfp_net_rx_buf *rxbuf;
struct nfp_net_rx_desc *rxd;
@ -1608,11 +1625,12 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget)
data_len = le16_to_cpu(rxd->rxd.data_len);
pkt_len = data_len - meta_len;
pkt_off = NFP_NET_RX_BUF_HEADROOM + dp->rx_dma_off;
if (dp->rx_offset == NFP_NET_CFG_RX_OFFSET_DYNAMIC)
data_off = NFP_NET_RX_BUF_HEADROOM + meta_len;
pkt_off += meta_len;
else
data_off = NFP_NET_RX_BUF_HEADROOM + dp->rx_offset;
data_off += dp->rx_dma_off;
pkt_off += dp->rx_offset;
meta_off = pkt_off - meta_len;
/* Stats update */
u64_stats_update_begin(&r_vec->rx_sync);
@ -1621,7 +1639,7 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget)
u64_stats_update_end(&r_vec->rx_sync);
/* Pointer to start of metadata */
meta = rxbuf->frag + data_off - meta_len;
meta = rxbuf->frag + meta_off;
if (unlikely(meta_len > NFP_NET_MAX_PREPEND ||
(dp->rx_offset && meta_len > dp->rx_offset))) {
@ -1631,6 +1649,9 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget)
continue;
}
nfp_net_dma_sync_cpu_rx(dp, rxbuf->dma_addr + meta_off,
data_len);
if (xdp_prog && !(rxd->rxd.flags & PCIE_DESC_RX_BPF &&
dp->bpf_offload_xdp)) {
unsigned int dma_off;
@ -1638,10 +1659,6 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget)
int act;
hard_start = rxbuf->frag + NFP_NET_RX_BUF_HEADROOM;
dma_off = data_off - NFP_NET_RX_BUF_HEADROOM;
dma_sync_single_for_cpu(dp->dev, rxbuf->dma_addr,
dma_off + pkt_len,
DMA_BIDIRECTIONAL);
/* Move prepend out of the way */
if (xdp_prog->xdp_adjust_head) {
@ -1650,12 +1667,12 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget)
}
act = nfp_net_run_xdp(xdp_prog, rxbuf->frag, hard_start,
&data_off, &pkt_len);
&pkt_off, &pkt_len);
switch (act) {
case XDP_PASS:
break;
case XDP_TX:
dma_off = data_off - NFP_NET_RX_BUF_HEADROOM;
dma_off = pkt_off - NFP_NET_RX_BUF_HEADROOM;
if (unlikely(!nfp_net_tx_xdp_buf(dp, rx_ring,
tx_ring, rxbuf,
dma_off,
@ -1689,7 +1706,7 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget)
nfp_net_rx_give_one(dp, rx_ring, new_frag, new_dma_addr);
skb_reserve(skb, data_off);
skb_reserve(skb, pkt_off);
skb_put(skb, pkt_len);
if (!dp->chained_metadata_format) {