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Message-ID: <20150821102430.GD19683@calimero.vinschen.de>
Date: Fri, 21 Aug 2015 12:24:30 +0200
From: Corinna Vinschen <vinschen@...hat.com>
To: netdev@...r.kernel.org
Cc: Hayes Wang <hayeswang@...ltek.com>,
Francois Romieu <romieu@...zoreil.com>,
Ivan Vecera <ivecera@...hat.com>,
David Miller <davem@...emloft.net>,
nic_swsd <nic_swsd@...ltek.com>
Subject: Re: [PATCH v2 net-next] r8169: Add values missing in @get_stats64
from HW counters
Sorry, I forgot to mention that I tested this patch on three different
chip versions, RTL_GIGA_MAC_VER_23, RTL_GIGA_MAC_VER_33 and
RTL_GIGA_MAC_VER_35. I couldn't test on pre-RTL_GIGA_MAC_VER_19, but
the offset handling without counter reset already worked as expected on
later chip versions, so I'm pretty confident that older chip versions
should work accordingly.
On Aug 21 12:09, Corinna Vinschen wrote:
> The r8169 driver collects statistical information returned by
> @get_stats64 by counting them in the driver itself, even though many
> (but not all) of the values are already collected by tally counters
> (TCs) in the NIC. Some of these TC values are not returned by
> @get_stats64. Especially the received multicast packages are missing
> from /proc/net/dev.
>
> Rectify this by fetching the TCs and returning them from
> rtl8169_get_stats64.
>
> The counters collected in the driver obviously disappear as soon as the
> driver is unloaded so after a driver is loaded the counters always start
> at 0. The TCs on the other hand are only reset by a power cycle. Without
> further considerations the values collected by the driver would not match
> up against the TC values.
>
> This patch introduces a new function rtl8169_reset_counters which
> resets the TCs.
>
> Unfortunately chip versions prior to RTL_GIGA_MAC_VER_19 don't allow
> to reset the TCs programatically. Therefore introduce an addition to
> the rtl8169_private struct and a function rtl8169_init_counter_offsets
> to store the TCs at first rtl_open. Use these values as offsets in
> rtl8169_get_stats64.
>
> Signed-off-by: Corinna Vinschen <vinschen@...hat.com>
> ---
> drivers/net/ethernet/realtek/r8169.c | 107 +++++++++++++++++++++++++++++++++++
> 1 file changed, 107 insertions(+)
>
> diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c
> index f790f61..f26a48d 100644
> --- a/drivers/net/ethernet/realtek/r8169.c
> +++ b/drivers/net/ethernet/realtek/r8169.c
> @@ -637,6 +637,9 @@ enum rtl_register_content {
> /* _TBICSRBit */
> TBILinkOK = 0x02000000,
>
> + /* ResetCounterCommand */
> + CounterReset = 0x1,
> +
> /* DumpCounterCommand */
> CounterDump = 0x8,
>
> @@ -747,6 +750,14 @@ struct rtl8169_counters {
> __le16 tx_underun;
> };
>
> +struct rtl8169_tc_offsets {
> + bool inited;
> + __le64 tx_errors;
> + __le32 tx_multi_collision;
> + __le32 rx_multicast;
> + __le16 tx_aborted;
> +};
> +
> enum rtl_flag {
> RTL_FLAG_TASK_ENABLED,
> RTL_FLAG_TASK_SLOW_PENDING,
> @@ -824,6 +835,7 @@ struct rtl8169_private {
>
> struct mii_if_info mii;
> struct rtl8169_counters counters;
> + struct rtl8169_tc_offsets tc_offset;
> u32 saved_wolopts;
> u32 opts1_mask;
>
> @@ -2179,6 +2191,47 @@ static int rtl8169_get_sset_count(struct net_device *dev, int sset)
> }
> }
>
> +DECLARE_RTL_COND(rtl_reset_counters_cond)
> +{
> + void __iomem *ioaddr = tp->mmio_addr;
> +
> + return RTL_R32(CounterAddrLow) & CounterReset;
> +}
> +
> +static void rtl8169_reset_counters(struct net_device *dev)
> +{
> + struct rtl8169_private *tp = netdev_priv(dev);
> + void __iomem *ioaddr = tp->mmio_addr;
> + struct device *d = &tp->pci_dev->dev;
> + struct rtl8169_counters *counters;
> + dma_addr_t paddr;
> + u32 cmd;
> +
> + /*
> + * Versions prior to RTL_GIGA_MAC_VER_19 don't support resetting the
> + * tally counters.
> + */
> + if (tp->mac_version < RTL_GIGA_MAC_VER_19)
> + return;
> +
> + counters = dma_alloc_coherent(d, sizeof(*counters), &paddr, GFP_KERNEL);
> + if (!counters)
> + return;
> +
> + RTL_W32(CounterAddrHigh, (u64)paddr >> 32);
> + cmd = (u64)paddr & DMA_BIT_MASK(32);
> + RTL_W32(CounterAddrLow, cmd);
> + RTL_W32(CounterAddrLow, cmd | CounterReset);
> +
> + if (!rtl_udelay_loop_wait_low(tp, &rtl_reset_counters_cond, 10, 1000))
> + netif_warn(tp, hw, dev, "counter reset failed\n");
> +
> + RTL_W32(CounterAddrLow, 0);
> + RTL_W32(CounterAddrHigh, 0);
> +
> + dma_free_coherent(d, sizeof(*counters), counters, paddr);
> +}
> +
> DECLARE_RTL_COND(rtl_counters_cond)
> {
> void __iomem *ioaddr = tp->mmio_addr;
> @@ -2220,6 +2273,39 @@ static void rtl8169_update_counters(struct net_device *dev)
> dma_free_coherent(d, sizeof(*counters), counters, paddr);
> }
>
> +static void rtl8169_init_counter_offsets(struct net_device *dev)
> +{
> + struct rtl8169_private *tp = netdev_priv(dev);
> +
> + /*
> + * rtl8169_init_counter_offsets is called from rtl_open. On chip
> + * versions prior to RTL_GIGA_MAC_VER_19 the tally counters are only
> + * reset by a power cycle, while the counter values collected by the
> + * driver are reset at every driver unload/load cycle.
> + *
> + * To make sure the HW values returned by @get_stats64 match the SW
> + * values, we collect the initial values at first open(*) and use them
> + * as offsets to normalize the values returned by @get_stats64.
> + *
> + * (*) We can't call rtl8169_init_counter_offsets from rtl_init_one
> + * for the reason stated in rtl8169_update_counters; CmdRxEnb is only
> + * set at open time by rtl_hw_start.
> + */
> +
> + if (tp->tc_offset.inited)
> + return;
> +
> + rtl8169_reset_counters(dev);
> +
> + rtl8169_update_counters(dev);
> +
> + tp->tc_offset.tx_errors = tp->counters.tx_errors;
> + tp->tc_offset.tx_multi_collision = tp->counters.tx_multi_collision;
> + tp->tc_offset.rx_multicast = tp->counters.rx_multicast;
> + tp->tc_offset.tx_aborted = tp->counters.tx_aborted;
> + tp->tc_offset.inited = true;
> +}
> +
> static void rtl8169_get_ethtool_stats(struct net_device *dev,
> struct ethtool_stats *stats, u64 *data)
> {
> @@ -7631,6 +7717,8 @@ static int rtl_open(struct net_device *dev)
>
> rtl_hw_start(dev);
>
> + rtl8169_init_counter_offsets(dev);
> +
> netif_start_queue(dev);
>
> rtl_unlock_work(tp);
> @@ -7689,6 +7777,25 @@ rtl8169_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
> stats->rx_fifo_errors = dev->stats.rx_fifo_errors;
> stats->rx_missed_errors = dev->stats.rx_missed_errors;
>
> + /*
> + * Fetch additonal counter values missing in stats collected by driver
> + * from tally counters.
> + */
> + rtl8169_update_counters(dev);
> +
> + /*
> + * Subtract values fetched during initalization.
> + * See rtl8169_init_counter_offsets for a description why we do that.
> + */
> + stats->tx_errors = le64_to_cpu(tp->counters.tx_errors) -
> + le64_to_cpu(tp->tc_offset.tx_errors);
> + stats->collisions = le32_to_cpu(tp->counters.tx_multi_collision) -
> + le32_to_cpu(tp->tc_offset.tx_multi_collision);
> + stats->multicast = le32_to_cpu(tp->counters.rx_multicast) -
> + le32_to_cpu(tp->tc_offset.rx_multicast);
> + stats->tx_aborted_errors = le16_to_cpu(tp->counters.tx_aborted) -
> + le16_to_cpu(tp->tc_offset.tx_aborted);
> +
> return stats;
> }
>
> --
> 2.1.0
>
> --
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