Thread (1 message) 1 message, 1 author, 2023-02-03

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

From: Vladimir Oltean <olteanv@gmail.com>
Date: 2023-02-03 22:55:38
Also in: linux-arm-kernel, linux-mediatek, lkml

On Fri, Feb 03, 2023 at 07:05:08AM +0000, Daniel Golle wrote:
quoted hunk
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@makrotopia.org>
---
 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;
quoted hunk
+
 			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;
quoted hunk
+
+	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.
quoted hunk
+
+		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
quoted hunk
+
 		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
quoted hunk
 			   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;
 }
 
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