Re: [PATCH 6/9] net: ethernet: mtk_eth_soc: ppe: add support for flow accounting

From: Vladimir Oltean
Date: Fri Feb 03 2023 - 17:55:39 EST

Next message: Sean Christopherson: "Re: [Patch v4 12/13] KVM: selftests: Make vCPU exit reason test assertion common."
Previous message: Marek Szyprowski: "Re: [PATCH 5/9] ARM: dts: exynos: move exynos-bus nodes out of soc in Exynos4412"
In reply to: Daniel Golle: "[PATCH 6/9] net: ethernet: mtk_eth_soc: ppe: add support for flow accounting"
Next in thread: Daniel Golle: "[PATCH 7/9] net: pcs: add driver for MediaTek SGMII PCS"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

On Fri, Feb 03, 2023 at 07:05:08AM +0000, Daniel Golle wrote:
> The PPE units found in MT7622 and newer support packet and byte
> accounting of hw-offloaded flows. Add support for reading those counters
> as found in MediaTek's SDK[1], make them accessible via debugfs and add
> them to the flow offload stats.
>
> [1]: https://git01.mediatek.com/plugins/gitiles/openwrt/feeds/mtk-openwrt-feeds/+/bc6a6a375c800dc2b80e1a325a2c732d1737df92
> Signed-off-by: Daniel Golle <daniel@xxxxxxxxxxxxxx>
> ---
> drivers/net/ethernet/mediatek/mtk_eth_soc.c | 8 +-
> drivers/net/ethernet/mediatek/mtk_eth_soc.h | 1 +
> drivers/net/ethernet/mediatek/mtk_ppe.c | 110 +++++++++++++++++-
> drivers/net/ethernet/mediatek/mtk_ppe.h | 24 +++-
> .../net/ethernet/mediatek/mtk_ppe_debugfs.c | 9 +-
> .../net/ethernet/mediatek/mtk_ppe_offload.c | 7 ++
> drivers/net/ethernet/mediatek/mtk_ppe_regs.h | 14 +++
> 7 files changed, 168 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> index f09cd6a132c9..d50dea1f20f3 100644
> --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> @@ -4708,7 +4708,9 @@ static int mtk_probe(struct platform_device *pdev)
> u32 ppe_addr = eth->soc->reg_map->ppe_base + i * 0x400;
>
> eth->ppe[i] = mtk_ppe_init(eth, eth->base + ppe_addr,
> - eth->soc->offload_version, i);
> + eth->soc->offload_version, i,
> + eth->soc->has_accounting);

All arguments mtk_ppe_init() needs (this includes eth->soc->offload_version)
are already available to it. See, first line in mtk_ppe_init() is:

const struct mtk_soc_data *soc = eth->soc;

> +
> if (!eth->ppe[i]) {
> err = -ENOMEM;
> goto err_deinit_ppe;
> diff --git a/drivers/net/ethernet/mediatek/mtk_ppe.c b/drivers/net/ethernet/mediatek/mtk_ppe.c
> index 6883eb34cd8b..26fa89afc69a 100644
> --- a/drivers/net/ethernet/mediatek/mtk_ppe.c
> +++ b/drivers/net/ethernet/mediatek/mtk_ppe.c
> @@ -74,6 +74,46 @@ static int mtk_ppe_wait_busy(struct mtk_ppe *ppe)
> return ret;
> }
>
> +static int mtk_ppe_mib_wait_busy(struct mtk_ppe *ppe)
> +{
> + int ret;
> + u32 val;
> +
> + ret = readl_poll_timeout(ppe->base + MTK_PPE_MIB_SER_CR, val,
> + !(val & MTK_PPE_MIB_SER_CR_ST),
> + 20, MTK_PPE_WAIT_TIMEOUT_US);
> +
> + if (ret)
> + dev_err(ppe->dev, "MIB table busy");
> +
> + return ret;
> +}
> +
> +static int mtk_mib_entry_read(struct mtk_ppe *ppe, u16 index, u64 *bytes, u64 *packets)
> +{
> + u32 val, cnt_r0, cnt_r1, cnt_r2;
> + u32 byte_cnt_low, byte_cnt_high, pkt_cnt_low, pkt_cnt_high;
> +
> + val = FIELD_PREP(MTK_PPE_MIB_SER_CR_ADDR, index) | MTK_PPE_MIB_SER_CR_ST;
> + ppe_w32(ppe, MTK_PPE_MIB_SER_CR, val);
> +
> + if (mtk_ppe_mib_wait_busy(ppe))
> + return -ETIMEDOUT;

err = mtk_ppe_mib_wait_busy();
if (err)
return err;

> +
> + cnt_r0 = readl(ppe->base + MTK_PPE_MIB_SER_R0);
> + cnt_r1 = readl(ppe->base + MTK_PPE_MIB_SER_R1);
> + cnt_r2 = readl(ppe->base + MTK_PPE_MIB_SER_R2);
> +
> + byte_cnt_low = FIELD_GET(MTK_PPE_MIB_SER_R0_BYTE_CNT_LOW, cnt_r0);
> + byte_cnt_high = FIELD_GET(MTK_PPE_MIB_SER_R1_BYTE_CNT_HIGH, cnt_r1);
> + pkt_cnt_low = FIELD_GET(MTK_PPE_MIB_SER_R1_PKT_CNT_LOW, cnt_r1);
> + pkt_cnt_high = FIELD_GET(MTK_PPE_MIB_SER_R2_PKT_CNT_HIGH, cnt_r2);
> + *bytes = ((u64)byte_cnt_high << 32) | byte_cnt_low;
> + *packets = (pkt_cnt_high << 16) | pkt_cnt_low;
> +
> + return 0;
> +}
> +
> static void mtk_ppe_cache_clear(struct mtk_ppe *ppe)
> {
> ppe_set(ppe, MTK_PPE_CACHE_CTL, MTK_PPE_CACHE_CTL_CLEAR);
> struct mtk_ppe *mtk_ppe_init(struct mtk_eth *eth, void __iomem *base,
> - int version, int index)
> + int version, int index, bool accounting)
> {
> const struct mtk_soc_data *soc = eth->soc;
> struct device *dev = eth->dev;
> struct mtk_ppe *ppe;
> u32 foe_flow_size;
> void *foe;
> + struct mtk_mib_entry *mib;
> + struct mtk_foe_accounting *acct;
>
> ppe = devm_kzalloc(dev, sizeof(*ppe), GFP_KERNEL);
> if (!ppe)
> @@ -778,6 +856,7 @@ struct mtk_ppe *mtk_ppe_init(struct mtk_eth *eth, void __iomem *base,
> ppe->eth = eth;
> ppe->dev = dev;
> ppe->version = version;
> + ppe->accounting = accounting;
>
> foe = dmam_alloc_coherent(ppe->dev,
> MTK_PPE_ENTRIES * soc->foe_entry_size,
> @@ -793,6 +872,25 @@ struct mtk_ppe *mtk_ppe_init(struct mtk_eth *eth, void __iomem *base,
> if (!ppe->foe_flow)
> goto err_free_l2_flows;
>
> + if (accounting) {
> + mib = dmam_alloc_coherent(ppe->dev, MTK_PPE_ENTRIES * sizeof(*mib),
> + &ppe->mib_phys, GFP_KERNEL);
> + if (!mib)
> + return NULL;
> +
> + memset(mib, 0, MTK_PPE_ENTRIES * sizeof(*mib));

I remember Jakub pointing out in another email that consistent DMA
memory is already zero-initialized, and it appears in
scripts/coccinelle/api/alloc/zalloc-simple.cocci.

> +
> + ppe->mib_table = mib;
> +
> + acct = devm_kzalloc(dev, MTK_PPE_ENTRIES * sizeof(*acct),
> + GFP_KERNEL);
> +
> + if (!acct)
> + return NULL;
> +
> + ppe->acct_table = acct;
> + }
> +
> mtk_ppe_debugfs_init(ppe, index);
>
> return ppe;
> @@ -922,6 +1020,16 @@ void mtk_ppe_start(struct mtk_ppe *ppe)
> ppe_w32(ppe, MTK_PPE_DEFAULT_CPU_PORT1, 0xcb777);
> ppe_w32(ppe, MTK_PPE_SBW_CTRL, 0x7f);
> }
> +
> + if (ppe->accounting && ppe->mib_phys) {
> + ppe_w32(ppe, MTK_PPE_MIB_TB_BASE, ppe->mib_phys);
> + ppe_m32(ppe, MTK_PPE_MIB_CFG, MTK_PPE_MIB_CFG_EN,
> + MTK_PPE_MIB_CFG_EN);
> + ppe_m32(ppe, MTK_PPE_MIB_CFG, MTK_PPE_MIB_CFG_RD_CLR,
> + MTK_PPE_MIB_CFG_RD_CLR);
> + ppe_m32(ppe, MTK_PPE_MIB_CACHE_CTL, MTK_PPE_MIB_CACHE_CTL_EN,
> + MTK_PPE_MIB_CFG_RD_CLR);
> + }
> }
>
> int mtk_ppe_stop(struct mtk_ppe *ppe)
> diff --git a/drivers/net/ethernet/mediatek/mtk_ppe_debugfs.c b/drivers/net/ethernet/mediatek/mtk_ppe_debugfs.c
> index 391b071bcff3..39775740340b 100644
> --- a/drivers/net/ethernet/mediatek/mtk_ppe_debugfs.c
> +++ b/drivers/net/ethernet/mediatek/mtk_ppe_debugfs.c
> @@ -82,6 +82,7 @@ mtk_ppe_debugfs_foe_show(struct seq_file *m, void *private, bool bind)
> struct mtk_foe_entry *entry = mtk_foe_get_entry(ppe, i);
> struct mtk_foe_mac_info *l2;
> struct mtk_flow_addr_info ai = {};
> + struct mtk_foe_accounting *acct;
> unsigned char h_source[ETH_ALEN];
> unsigned char h_dest[ETH_ALEN];
> int type, state;
> @@ -95,6 +96,8 @@ mtk_ppe_debugfs_foe_show(struct seq_file *m, void *private, bool bind)
> if (bind && state != MTK_FOE_STATE_BIND)
> continue;
>
> + acct = mtk_foe_entry_get_mib(ppe, i, NULL);

might return NULL

> +
> type = FIELD_GET(MTK_FOE_IB1_PACKET_TYPE, entry->ib1);
> seq_printf(m, "%05x %s %7s", i,
> mtk_foe_entry_state_str(state),
> @@ -153,9 +156,11 @@ mtk_ppe_debugfs_foe_show(struct seq_file *m, void *private, bool bind)
> *((__be16 *)&h_dest[4]) = htons(l2->dest_mac_lo);
>
> seq_printf(m, " eth=%pM->%pM etype=%04x"
> - " vlan=%d,%d ib1=%08x ib2=%08x\n",
> + " vlan=%d,%d ib1=%08x ib2=%08x"
> + " packets=%lld bytes=%lld\n",

%llu

> h_source, h_dest, ntohs(l2->etype),
> - l2->vlan1, l2->vlan2, entry->ib1, ib2);
> + l2->vlan1, l2->vlan2, entry->ib1, ib2,
> + acct->packets, acct->bytes);
> }
>
> return 0;
> diff --git a/drivers/net/ethernet/mediatek/mtk_ppe_offload.c b/drivers/net/ethernet/mediatek/mtk_ppe_offload.c
> index 81afd5ee3fbf..832e11ad9a16 100644
> --- a/drivers/net/ethernet/mediatek/mtk_ppe_offload.c
> +++ b/drivers/net/ethernet/mediatek/mtk_ppe_offload.c
> @@ -497,6 +497,7 @@ static int
> mtk_flow_offload_stats(struct mtk_eth *eth, struct flow_cls_offload *f)
> {
> struct mtk_flow_entry *entry;
> + struct mtk_foe_accounting diff;
> u32 idle;
>
> entry = rhashtable_lookup(&eth->flow_table, &f->cookie,
> @@ -507,6 +508,12 @@ mtk_flow_offload_stats(struct mtk_eth *eth, struct flow_cls_offload *f)
> idle = mtk_foe_entry_idle_time(eth->ppe[entry->ppe_index], entry);
> f->stats.lastused = jiffies - idle * HZ;
>
> + if (entry->hash != 0xFFFF) {
> + mtk_foe_entry_get_mib(eth->ppe[entry->ppe_index], entry->hash, &diff);

If this returns NULL, you don't want to add diff.packets and diff.bytes
to f->stats, because no one bothers to initialize "diff" to all-zeroes.
So it contains junk from kernel stack memory. You might want to avoid this.

> + f->stats.pkts += diff.packets;
> + f->stats.bytes += diff.bytes;
> + }
> +
> return 0;
> }
>

Next message: Sean Christopherson: "Re: [Patch v4 12/13] KVM: selftests: Make vCPU exit reason test assertion common."
Previous message: Marek Szyprowski: "Re: [PATCH 5/9] ARM: dts: exynos: move exynos-bus nodes out of soc in Exynos4412"
In reply to: Daniel Golle: "[PATCH 6/9] net: ethernet: mtk_eth_soc: ppe: add support for flow accounting"
Next in thread: Daniel Golle: "[PATCH 7/9] net: pcs: add driver for MediaTek SGMII PCS"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]