[PATCH net-next v2 0/3] net: ethernet: ti: Address some warnings

[PATCH net-next v2 0/3] net: ethernet: ti: Address some warnings

[Simon Horman]

Hi,

This patchset addresses some warnings flagged by Sparse, and clang-18 in
TI Ethernet drivers.

Although these changes do not alter the functionality of the code, by
addressing them real problems introduced in future which are flagged by
tooling will stand out more readily.

Compile tested only.

---
Changes in v2:
- Dropped patch to directly address __percpu Sparse warnings and, instead
- Add patch to use tstats
- Added tags
- Thanks to all for the review of v1
- Link to v1: https://lore.kernel.org/r/20240910-ti-warn-v1-0-afd1e404abbe@kernel.org

---
Simon Horman (3):
      net: ethernet: ti: am65-cpsw: Use __be64 type for id_temp
      net: ethernet: ti: am65-cpsw: Use tstats instead of open coded version
      net: ethernet: ti: cpsw_ale: Remove unused accessor functions

 drivers/net/ethernet/ti/am65-cpsw-nuss.c | 94 +++-----------------------------
 drivers/net/ethernet/ti/am65-cpsw-nuss.h |  9 ---
 drivers/net/ethernet/ti/cpsw_ale.c       | 30 +++++++---
 3 files changed, 30 insertions(+), 103 deletions(-)

base-commit: 09cf85ef183a5603db49d542264ddbece3258e55

[PATCH net-next v2 1/3] net: ethernet: ti: am65-cpsw: Use __be64 type for id_temp

[Simon Horman]

The id_temp local variable in am65_cpsw_nuss_probe() is
used to hold a 64-bit big-endian value as it is assigned using
cpu_to_be64().

It is read using memcpy(), where it is written as an identifier into a
byte-array.  So this can also be treated as big endian.

As it's type is currently host byte order (u64), sparse flags
an endian mismatch when compiling for little-endian systems:

.../am65-cpsw-nuss.c:3454:17: warning: incorrect type in assignment (different base types)
.../am65-cpsw-nuss.c:3454:17:    expected unsigned long long [usertype] id_temp
.../am65-cpsw-nuss.c:3454:17:    got restricted __be64 [usertype]

Address this by using __be64 as the type of id_temp.

No functional change intended.
Compile tested only.

Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Reviewed-by: Roger Quadros <rogerq@kernel.org>
Signed-off-by: Simon Horman <horms@kernel.org>
---
 drivers/net/ethernet/ti/am65-cpsw-nuss.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/ti/am65-cpsw-nuss.c b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
index 12ccdd3f19aa..b08e2c3aeda3 100644
--- a/drivers/net/ethernet/ti/am65-cpsw-nuss.c
+++ b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
@@ -3497,7 +3497,7 @@ static int am65_cpsw_nuss_probe(struct platform_device *pdev)
 	struct resource *res;
 	struct clk *clk;
 	int ale_entries;
-	u64 id_temp;
+	__be64 id_temp;
 	int ret, i;
 
 	common = devm_kzalloc(dev, sizeof(struct am65_cpsw_common), GFP_KERNEL);

-- 
2.45.2

[PATCH net-next v2 2/3] net: ethernet: ti: am65-cpsw: Use tstats instead of open coded version

[Simon Horman]

Make use of struct pcpu_sw_netstats and related helpers to handle
existing per-cpu stats for this driver - the exact same counters
are maintained.

A side effect of this change is to address __percpu warnings
flagged by Sparse:

.../am65-cpsw-nuss.c:2658:55: warning: incorrect type in initializer (different address spaces)
.../am65-cpsw-nuss.c:2658:55:    expected struct am65_cpsw_ndev_stats [noderef] __percpu *stats
.../am65-cpsw-nuss.c:2658:55:    got void *data
.../am65-cpsw-nuss.c:2781:15: warning: incorrect type in argument 3 (different address spaces)
.../am65-cpsw-nuss.c:2781:15:    expected void *data
.../am65-cpsw-nuss.c:2781:15:    got struct am65_cpsw_ndev_stats [noderef] __percpu *stats

Compile tested only.
No functional change intended.

Suggested-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/all/20240911170643.7ecb1bbb@kernel.org/
Signed-off-by: Simon Horman <horms@kernel.org>
---
I did look at also dropping am65_cpsw_nuss_ndo_get_stats, the custom
implementation of ndo_get_stats64 by using dev_core_stats.
However, I couldn't see how to handle rx_errors.
---
 drivers/net/ethernet/ti/am65-cpsw-nuss.c | 92 +++-----------------------------
 drivers/net/ethernet/ti/am65-cpsw-nuss.h |  9 ----
 2 files changed, 8 insertions(+), 93 deletions(-)

diff --git a/drivers/net/ethernet/ti/am65-cpsw-nuss.c b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
index b08e2c3aeda3..50b0c8d22b9c 100644
--- a/drivers/net/ethernet/ti/am65-cpsw-nuss.c
+++ b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
@@ -1031,9 +1031,7 @@ static int am65_cpsw_run_xdp(struct am65_cpsw_rx_flow *flow,
 			     int desc_idx, int cpu, int *len)
 {
 	struct am65_cpsw_common *common = flow->common;
-	struct am65_cpsw_ndev_priv *ndev_priv;
 	struct net_device *ndev = port->ndev;
-	struct am65_cpsw_ndev_stats *stats;
 	int ret = AM65_CPSW_XDP_CONSUMED;
 	struct am65_cpsw_tx_chn *tx_chn;
 	struct netdev_queue *netif_txq;
@@ -1051,9 +1049,6 @@ static int am65_cpsw_run_xdp(struct am65_cpsw_rx_flow *flow,
 	/* XDP prog might have changed packet data and boundaries */
 	*len = xdp->data_end - xdp->data;
 
-	ndev_priv = netdev_priv(ndev);
-	stats = this_cpu_ptr(ndev_priv->stats);
-
 	switch (act) {
 	case XDP_PASS:
 		ret = AM65_CPSW_XDP_PASS;
@@ -1073,20 +1068,14 @@ static int am65_cpsw_run_xdp(struct am65_cpsw_rx_flow *flow,
 		if (err)
 			goto drop;
 
-		u64_stats_update_begin(&stats->syncp);
-		stats->rx_bytes += *len;
-		stats->rx_packets++;
-		u64_stats_update_end(&stats->syncp);
+		dev_sw_netstats_tx_add(ndev, 1, *len);
 		ret = AM65_CPSW_XDP_CONSUMED;
 		goto out;
 	case XDP_REDIRECT:
 		if (unlikely(xdp_do_redirect(ndev, xdp, prog)))
 			goto drop;
 
-		u64_stats_update_begin(&stats->syncp);
-		stats->rx_bytes += *len;
-		stats->rx_packets++;
-		u64_stats_update_end(&stats->syncp);
+		dev_sw_netstats_rx_add(ndev, *len);
 		ret = AM65_CPSW_XDP_REDIRECT;
 		goto out;
 	default:
@@ -1147,7 +1136,6 @@ static int am65_cpsw_nuss_rx_packets(struct am65_cpsw_rx_flow *flow,
 	u32 buf_dma_len, pkt_len, port_id = 0, csum_info;
 	struct am65_cpsw_common *common = flow->common;
 	struct am65_cpsw_ndev_priv *ndev_priv;
-	struct am65_cpsw_ndev_stats *stats;
 	struct cppi5_host_desc_t *desc_rx;
 	struct device *dev = common->dev;
 	struct page *page, *new_page;
@@ -1233,12 +1221,7 @@ static int am65_cpsw_nuss_rx_packets(struct am65_cpsw_rx_flow *flow,
 	am65_cpsw_nuss_rx_csum(skb, csum_info);
 	napi_gro_receive(&flow->napi_rx, skb);
 
-	stats = this_cpu_ptr(ndev_priv->stats);
-
-	u64_stats_update_begin(&stats->syncp);
-	stats->rx_packets++;
-	stats->rx_bytes += pkt_len;
-	u64_stats_update_end(&stats->syncp);
+	dev_sw_netstats_rx_add(ndev, pkt_len);
 
 allocate:
 	new_page = page_pool_dev_alloc_pages(flow->page_pool);
@@ -1321,10 +1304,7 @@ static struct sk_buff *
 am65_cpsw_nuss_tx_compl_packet_skb(struct am65_cpsw_tx_chn *tx_chn,
 				   dma_addr_t desc_dma)
 {
-	struct am65_cpsw_ndev_priv *ndev_priv;
-	struct am65_cpsw_ndev_stats *stats;
 	struct cppi5_host_desc_t *desc_tx;
-	struct net_device *ndev;
 	struct sk_buff *skb;
 	void **swdata;
 
@@ -1334,16 +1314,9 @@ am65_cpsw_nuss_tx_compl_packet_skb(struct am65_cpsw_tx_chn *tx_chn,
 	skb = *(swdata);
 	am65_cpsw_nuss_xmit_free(tx_chn, desc_tx);
 
-	ndev = skb->dev;
-
 	am65_cpts_tx_timestamp(tx_chn->common->cpts, skb);
 
-	ndev_priv = netdev_priv(ndev);
-	stats = this_cpu_ptr(ndev_priv->stats);
-	u64_stats_update_begin(&stats->syncp);
-	stats->tx_packets++;
-	stats->tx_bytes += skb->len;
-	u64_stats_update_end(&stats->syncp);
+	dev_sw_netstats_tx_add(skb->dev, 1, skb->len);
 
 	return skb;
 }
@@ -1354,8 +1327,6 @@ am65_cpsw_nuss_tx_compl_packet_xdp(struct am65_cpsw_common *common,
 				   dma_addr_t desc_dma,
 				   struct net_device **ndev)
 {
-	struct am65_cpsw_ndev_priv *ndev_priv;
-	struct am65_cpsw_ndev_stats *stats;
 	struct cppi5_host_desc_t *desc_tx;
 	struct am65_cpsw_port *port;
 	struct xdp_frame *xdpf;
@@ -1369,14 +1340,7 @@ am65_cpsw_nuss_tx_compl_packet_xdp(struct am65_cpsw_common *common,
 	am65_cpsw_nuss_xmit_free(tx_chn, desc_tx);
 
 	port = am65_common_get_port(common, port_id);
-	*ndev = port->ndev;
-
-	ndev_priv = netdev_priv(*ndev);
-	stats = this_cpu_ptr(ndev_priv->stats);
-	u64_stats_update_begin(&stats->syncp);
-	stats->tx_packets++;
-	stats->tx_bytes += xdpf->len;
-	u64_stats_update_end(&stats->syncp);
+	dev_sw_netstats_tx_add(port->ndev, 1, xdpf->len);
 
 	return xdpf;
 }
@@ -1899,31 +1863,7 @@ static int am65_cpsw_nuss_ndo_slave_ioctl(struct net_device *ndev,
 static void am65_cpsw_nuss_ndo_get_stats(struct net_device *dev,
 					 struct rtnl_link_stats64 *stats)
 {
-	struct am65_cpsw_ndev_priv *ndev_priv = netdev_priv(dev);
-	unsigned int start;
-	int cpu;
-
-	for_each_possible_cpu(cpu) {
-		struct am65_cpsw_ndev_stats *cpu_stats;
-		u64 rx_packets;
-		u64 rx_bytes;
-		u64 tx_packets;
-		u64 tx_bytes;
-
-		cpu_stats = per_cpu_ptr(ndev_priv->stats, cpu);
-		do {
-			start = u64_stats_fetch_begin(&cpu_stats->syncp);
-			rx_packets = cpu_stats->rx_packets;
-			rx_bytes   = cpu_stats->rx_bytes;
-			tx_packets = cpu_stats->tx_packets;
-			tx_bytes   = cpu_stats->tx_bytes;
-		} while (u64_stats_fetch_retry(&cpu_stats->syncp, start));
-
-		stats->rx_packets += rx_packets;
-		stats->rx_bytes   += rx_bytes;
-		stats->tx_packets += tx_packets;
-		stats->tx_bytes   += tx_bytes;
-	}
+	dev_fetch_sw_netstats(stats, dev->tstats);
 
 	stats->rx_errors	= dev->stats.rx_errors;
 	stats->rx_dropped	= dev->stats.rx_dropped;
@@ -2710,13 +2650,6 @@ static int am65_cpsw_nuss_init_slave_ports(struct am65_cpsw_common *common)
 	return ret;
 }
 
-static void am65_cpsw_pcpu_stats_free(void *data)
-{
-	struct am65_cpsw_ndev_stats __percpu *stats = data;
-
-	free_percpu(stats);
-}
-
 static void am65_cpsw_nuss_phylink_cleanup(struct am65_cpsw_common *common)
 {
 	struct am65_cpsw_port *port;
@@ -2736,7 +2669,6 @@ am65_cpsw_nuss_init_port_ndev(struct am65_cpsw_common *common, u32 port_idx)
 	struct device *dev = common->dev;
 	struct am65_cpsw_port *port;
 	struct phylink *phylink;
-	int ret;
 
 	port = &common->ports[port_idx];
 
@@ -2830,21 +2762,13 @@ am65_cpsw_nuss_init_port_ndev(struct am65_cpsw_common *common, u32 port_idx)
 	if (common->pdata.quirks & AM65_CPSW_QUIRK_I2027_NO_TX_CSUM)
 		port->ndev->features &= ~NETIF_F_HW_CSUM;
 
-	ndev_priv->stats = netdev_alloc_pcpu_stats(struct am65_cpsw_ndev_stats);
-	if (!ndev_priv->stats)
-		return -ENOMEM;
-
-	ret = devm_add_action_or_reset(dev, am65_cpsw_pcpu_stats_free,
-				       ndev_priv->stats);
-	if (ret)
-		dev_err(dev, "failed to add percpu stat free action %d\n", ret);
-
+	port->ndev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
 	port->xdp_prog = NULL;
 
 	if (!common->dma_ndev)
 		common->dma_ndev = port->ndev;
 
-	return ret;
+	return 0;
 }
 
 static int am65_cpsw_nuss_init_ndevs(struct am65_cpsw_common *common)
diff --git a/drivers/net/ethernet/ti/am65-cpsw-nuss.h b/drivers/net/ethernet/ti/am65-cpsw-nuss.h
index dc8d544230dc..3f3e353dfe88 100644
--- a/drivers/net/ethernet/ti/am65-cpsw-nuss.h
+++ b/drivers/net/ethernet/ti/am65-cpsw-nuss.h
@@ -180,18 +180,9 @@ struct am65_cpsw_common {
 	u32			*ale_context;
 };
 
-struct am65_cpsw_ndev_stats {
-	u64 tx_packets;
-	u64 tx_bytes;
-	u64 rx_packets;
-	u64 rx_bytes;
-	struct u64_stats_sync syncp;
-};
-
 struct am65_cpsw_ndev_priv {
 	u32			msg_enable;
 	struct am65_cpsw_port	*port;
-	struct am65_cpsw_ndev_stats __percpu *stats;
 	bool offload_fwd_mark;
 	/* Serialize access to MAC Merge state between ethtool requests
 	 * and link state updates

-- 
2.45.2

[PATCH net-next v2 3/3] net: ethernet: ti: cpsw_ale: Remove unused accessor functions

[Simon Horman]

W=1 builds flag that some accessor functions for ALE fields are unused.

Address this by splitting up the macros used to define these
accessors to allow only those that are used to be declared.

The warnings are verbose, but for example, the mcast_state case is
flagged by clang-18 as:

.../cpsw_ale.c:220:1: warning: unused function 'cpsw_ale_get_mcast_state' [-Wunused-function]
  220 | DEFINE_ALE_FIELD(mcast_state,           62,     2)
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.../cpsw_ale.c:145:19: note: expanded from macro 'DEFINE_ALE_FIELD'
  145 | static inline int cpsw_ale_get_##name(u32 *ale_entry)                   \
      |                   ^~~~~~~~~~~~~~~~~~~
<scratch space>:196:1: note: expanded from here
  196 | cpsw_ale_get_mcast_state
      | ^~~~~~~~~~~~~~~~~~~~~~~~

Compile tested only.
No functional change intended.

Signed-off-by: Simon Horman <horms@kernel.org>
---
 drivers/net/ethernet/ti/cpsw_ale.c | 30 +++++++++++++++++++++---------
 1 file changed, 21 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/ti/cpsw_ale.c b/drivers/net/ethernet/ti/cpsw_ale.c
index 8d02d2b21429..d361caa80d05 100644
--- a/drivers/net/ethernet/ti/cpsw_ale.c
+++ b/drivers/net/ethernet/ti/cpsw_ale.c
@@ -162,27 +162,39 @@ static inline void cpsw_ale_set_field(u32 *ale_entry, u32 start, u32 bits,
 	ale_entry[idx] |=  (value << start);
 }
 
-#define DEFINE_ALE_FIELD(name, start, bits)				\
+#define DEFINE_ALE_FIELD_GET(name, start, bits)				\
 static inline int cpsw_ale_get_##name(u32 *ale_entry)			\
 {									\
 	return cpsw_ale_get_field(ale_entry, start, bits);		\
-}									\
+}
+
+#define DEFINE_ALE_FIELD_SET(name, start, bits)				\
 static inline void cpsw_ale_set_##name(u32 *ale_entry, u32 value)	\
 {									\
 	cpsw_ale_set_field(ale_entry, start, bits, value);		\
 }
 
-#define DEFINE_ALE_FIELD1(name, start)					\
+#define DEFINE_ALE_FIELD(name, start, bits)				\
+DEFINE_ALE_FIELD_GET(name, start, bits)					\
+DEFINE_ALE_FIELD_SET(name, start, bits)
+
+#define DEFINE_ALE_FIELD1_GET(name, start)				\
 static inline int cpsw_ale_get_##name(u32 *ale_entry, u32 bits)		\
 {									\
 	return cpsw_ale_get_field(ale_entry, start, bits);		\
-}									\
+}
+
+#define DEFINE_ALE_FIELD1_SET(name, start)				\
 static inline void cpsw_ale_set_##name(u32 *ale_entry, u32 value,	\
 		u32 bits)						\
 {									\
 	cpsw_ale_set_field(ale_entry, start, bits, value);		\
 }
 
+#define DEFINE_ALE_FIELD1(name, start)					\
+DEFINE_ALE_FIELD1_GET(name, start)					\
+DEFINE_ALE_FIELD1_SET(name, start)
+
 enum {
 	ALE_ENT_VID_MEMBER_LIST = 0,
 	ALE_ENT_VID_UNREG_MCAST_MSK,
@@ -238,14 +250,14 @@ static const struct ale_entry_fld vlan_entry_k3_cpswxg[] = {
 
 DEFINE_ALE_FIELD(entry_type,		60,	2)
 DEFINE_ALE_FIELD(vlan_id,		48,	12)
-DEFINE_ALE_FIELD(mcast_state,		62,	2)
+DEFINE_ALE_FIELD_SET(mcast_state,	62,	2)
 DEFINE_ALE_FIELD1(port_mask,		66)
 DEFINE_ALE_FIELD(super,			65,	1)
 DEFINE_ALE_FIELD(ucast_type,		62,     2)
-DEFINE_ALE_FIELD1(port_num,		66)
-DEFINE_ALE_FIELD(blocked,		65,     1)
-DEFINE_ALE_FIELD(secure,		64,     1)
-DEFINE_ALE_FIELD(mcast,			40,	1)
+DEFINE_ALE_FIELD1_SET(port_num,		66)
+DEFINE_ALE_FIELD_SET(blocked,		65,     1)
+DEFINE_ALE_FIELD_SET(secure,		64,     1)
+DEFINE_ALE_FIELD_GET(mcast,		40,	1)
 
 #define NU_VLAN_UNREG_MCAST_IDX	1
 

-- 
2.45.2

Re: [PATCH net-next v2 2/3] net: ethernet: ti: am65-cpsw: Use tstats instead of open coded version

[Roger Quadros]

Hi Simon,

On 10/10/2024 14:04, Simon Horman wrote:
> Make use of struct pcpu_sw_netstats and related helpers to handle
> existing per-cpu stats for this driver - the exact same counters
> are maintained.
> 
> A side effect of this change is to address __percpu warnings
> flagged by Sparse:
> 
> .../am65-cpsw-nuss.c:2658:55: warning: incorrect type in initializer (different address spaces)
> .../am65-cpsw-nuss.c:2658:55:    expected struct am65_cpsw_ndev_stats [noderef] __percpu *stats
> .../am65-cpsw-nuss.c:2658:55:    got void *data
> .../am65-cpsw-nuss.c:2781:15: warning: incorrect type in argument 3 (different address spaces)
> .../am65-cpsw-nuss.c:2781:15:    expected void *data
> .../am65-cpsw-nuss.c:2781:15:    got struct am65_cpsw_ndev_stats [noderef] __percpu *stats
> 
> Compile tested only.
> No functional change intended.
> 
> Suggested-by: Jakub Kicinski <kuba@kernel.org>
> Link: https://lore.kernel.org/all/20240911170643.7ecb1bbb@kernel.org/
> Signed-off-by: Simon Horman <horms@kernel.org>

Thanks for this cleanup! I did a quick test and rx/tx stats seem to work fine.

Reviewed-by: Roger Quadros <rogerq@kernel.org>

Re: [PATCH net-next v2 3/3] net: ethernet: ti: cpsw_ale: Remove unused accessor functions

[Roger Quadros]

On 10/10/2024 14:04, Simon Horman wrote:
> W=1 builds flag that some accessor functions for ALE fields are unused.
> 
> Address this by splitting up the macros used to define these
> accessors to allow only those that are used to be declared.
> 
> The warnings are verbose, but for example, the mcast_state case is
> flagged by clang-18 as:
> 
> .../cpsw_ale.c:220:1: warning: unused function 'cpsw_ale_get_mcast_state' [-Wunused-function]
>   220 | DEFINE_ALE_FIELD(mcast_state,           62,     2)
>       | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> .../cpsw_ale.c:145:19: note: expanded from macro 'DEFINE_ALE_FIELD'
>   145 | static inline int cpsw_ale_get_##name(u32 *ale_entry)                   \
>       |                   ^~~~~~~~~~~~~~~~~~~
> <scratch space>:196:1: note: expanded from here
>   196 | cpsw_ale_get_mcast_state
>       | ^~~~~~~~~~~~~~~~~~~~~~~~
> 
> Compile tested only.
> No functional change intended.
> 
> Signed-off-by: Simon Horman <horms@kernel.org>

Reviewed-by: Roger Quadros <rogerq@kernel.org>

Re: [PATCH net-next v2 0/3] net: ethernet: ti: Address some warnings

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net-next.git (main)
by David S. Miller <davem@davemloft.net>:

On Thu, 10 Oct 2024 12:04:09 +0100 you wrote:
> Hi,
> 
> This patchset addresses some warnings flagged by Sparse, and clang-18 in
> TI Ethernet drivers.
> 
> Although these changes do not alter the functionality of the code, by
> addressing them real problems introduced in future which are flagged by
> tooling will stand out more readily.
> 
> [...]

Here is the summary with links:
  - [net-next,v2,1/3] net: ethernet: ti: am65-cpsw: Use __be64 type for id_temp
    https://git.kernel.org/netdev/net-next/c/5c16e118b796
  - [net-next,v2,2/3] net: ethernet: ti: am65-cpsw: Use tstats instead of open coded version
    https://git.kernel.org/netdev/net-next/c/4a7b2ba94a59
  - [net-next,v2,3/3] net: ethernet: ti: cpsw_ale: Remove unused accessor functions
    https://git.kernel.org/netdev/net-next/c/2c9eacbb56de

You are awesome, thank you!
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