[PATCH net-next v3 0/2] net: stmmac: Tx coe sw fallback

[PATCH net-next v3 0/2] net: stmmac: Tx coe sw fallback

[Rohan G Thomas]

Hi,
Some DWMAC IPs support tx coe only for a few initial tx queues,
starting from tx queue 0. This patchset adds support for tx coe sw
fallback for those queues that don't support tx coe. Also, add binding
for snps,tx-queues-with-coe property.

changelog v3:
* Resend with complete email list

changelog v2: 
* Reformed binding description.
* Minor grammatical corrections in comments and commit messages.

Rohan G Thomas (2):
  dt-bindings: net: snps,dwmac: Tx queues with coe
  net: stmmac: Tx coe sw fallback

 .../devicetree/bindings/net/snps,dwmac.yaml   |  3 +++
 drivers/net/ethernet/stmicro/stmmac/stmmac.h  |  2 ++
 .../net/ethernet/stmicro/stmmac/stmmac_main.c | 19 +++++++++++++++++++
 .../ethernet/stmicro/stmmac/stmmac_platform.c |  4 ++++
 include/linux/stmmac.h                        |  1 +
 5 files changed, 29 insertions(+)

-- 
2.19.0

[PATCH net-next v3 1/2] dt-bindings: net: snps,dwmac: Tx queues with coe

[Rohan G Thomas]

Add dt-bindings for the number of tx queues with coe support. Some
dwmac IPs support tx queues only for a few initial tx queues,
starting from tx queue 0.

Signed-off-by: Rohan G Thomas <rohan.g.thomas@intel.com>
---
 Documentation/devicetree/bindings/net/snps,dwmac.yaml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/snps,dwmac.yaml b/Documentation/devicetree/bindings/net/snps,dwmac.yaml
index ddf9522a5dc2..0c6431c10cf9 100644
--- a/Documentation/devicetree/bindings/net/snps,dwmac.yaml
+++ b/Documentation/devicetree/bindings/net/snps,dwmac.yaml
@@ -313,6 +313,9 @@ properties:
       snps,tx-queues-to-use:
         $ref: /schemas/types.yaml#/definitions/uint32
         description: number of TX queues to be used in the driver
+      snps,tx-queues-with-coe:
+        $ref: /schemas/types.yaml#/definitions/uint32
+        description: number of TX queues that support TX checksum offloading
       snps,tx-sched-wrr:
         type: boolean
         description: Weighted Round Robin
-- 
2.19.0

Re: [PATCH net-next v3 1/2] dt-bindings: net: snps,dwmac: Tx queues with coe

[Conor Dooley]

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On Mon, Aug 14, 2023 at 10:06:36PM +0800, Rohan G Thomas wrote:
> Add dt-bindings for the number of tx queues with coe support. Some
> dwmac IPs support tx queues only for a few initial tx queues,
> starting from tx queue 0.
> 
> Signed-off-by: Rohan G Thomas <rohan.g.thomas@intel.com>

Acked-by: Conor Dooley <conor.dooley@microchip.com>

Thanks,
Conor.

> ---
>  Documentation/devicetree/bindings/net/snps,dwmac.yaml | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/net/snps,dwmac.yaml b/Documentation/devicetree/bindings/net/snps,dwmac.yaml
> index ddf9522a5dc2..0c6431c10cf9 100644
> --- a/Documentation/devicetree/bindings/net/snps,dwmac.yaml
> +++ b/Documentation/devicetree/bindings/net/snps,dwmac.yaml
> @@ -313,6 +313,9 @@ properties:
>        snps,tx-queues-to-use:
>          $ref: /schemas/types.yaml#/definitions/uint32
>          description: number of TX queues to be used in the driver
> +      snps,tx-queues-with-coe:
> +        $ref: /schemas/types.yaml#/definitions/uint32
> +        description: number of TX queues that support TX checksum offloading
>        snps,tx-sched-wrr:
>          type: boolean
>          description: Weighted Round Robin
> -- 
> 2.19.0
> 

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[PATCH net-next v3 2/2] net: stmmac: Tx coe sw fallback

[Rohan G Thomas]

Add sw fallback of tx checksum calculation for those tx queues that
don't support tx checksum offloading. Because, some DWMAC IPs support
tx checksum offloading only for a few initial tx queues, starting
from tx queue 0.

Signed-off-by: Rohan G Thomas <rohan.g.thomas@intel.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac.h  |  2 ++
 .../net/ethernet/stmicro/stmmac/stmmac_main.c | 19 +++++++++++++++++++
 .../ethernet/stmicro/stmmac/stmmac_platform.c |  4 ++++
 include/linux/stmmac.h                        |  1 +
 4 files changed, 26 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index 3401e888a9f6..f526bcaaaf64 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -219,6 +219,8 @@ struct stmmac_priv {
 	int hwts_tx_en;
 	bool tx_path_in_lpi_mode;
 	bool tso;
+	bool tx_q_coe_lmt;
+	u32 tx_q_with_coe;
 	int sph;
 	int sph_cap;
 	u32 sarc_type;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 733b5e900817..555d40bcc089 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -4409,6 +4409,17 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 	WARN_ON(tx_q->tx_skbuff[first_entry]);
 
 	csum_insertion = (skb->ip_summed == CHECKSUM_PARTIAL);
+	/* Some DWMAC IPs support tx coe only for a few initial tx queues,
+	 * starting from tx queue 0. So checksum offloading for those queues
+	 * that don't support tx coe needs to fallback to software checksum
+	 * calculation.
+	 */
+	if (csum_insertion && priv->tx_q_coe_lmt &&
+	    queue >= priv->tx_q_with_coe) {
+		if (unlikely(skb_checksum_help(skb)))
+			goto dma_map_err;
+		csum_insertion = !csum_insertion;
+	}
 
 	if (likely(priv->extend_desc))
 		desc = (struct dma_desc *)(tx_q->dma_etx + entry);
@@ -7401,6 +7412,14 @@ int stmmac_dvr_probe(struct device *device,
 		dev_info(priv->device, "SPH feature enabled\n");
 	}
 
+	if (priv->plat->tx_coe &&
+	    priv->plat->tx_queues_with_coe < priv->plat->tx_queues_to_use) {
+		priv->tx_q_coe_lmt = true;
+		priv->tx_q_with_coe = priv->plat->tx_queues_with_coe;
+		dev_info(priv->device, "TX COE limited to %u tx queues\n",
+			 priv->tx_q_with_coe);
+	}
+
 	/* Ideally our host DMA address width is the same as for the
 	 * device. However, it may differ and then we have to use our
 	 * host DMA width for allocation and the device DMA width for
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
index be8e79c7aa34..0138b7c9c7ab 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
@@ -225,6 +225,10 @@ static int stmmac_mtl_setup(struct platform_device *pdev,
 				 &plat->tx_queues_to_use))
 		plat->tx_queues_to_use = 1;
 
+	if (of_property_read_u32(tx_node, "snps,tx-queues-with-coe",
+				 &plat->tx_queues_with_coe))
+		plat->tx_queues_with_coe = plat->tx_queues_to_use;
+
 	if (of_property_read_bool(tx_node, "snps,tx-sched-wrr"))
 		plat->tx_sched_algorithm = MTL_TX_ALGORITHM_WRR;
 	else if (of_property_read_bool(tx_node, "snps,tx-sched-wfq"))
diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index 784277d666eb..cb508164eaea 100644
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h
@@ -252,6 +252,7 @@ struct plat_stmmacenet_data {
 	u32 host_dma_width;
 	u32 rx_queues_to_use;
 	u32 tx_queues_to_use;
+	u32 tx_queues_with_coe;
 	u8 rx_sched_algorithm;
 	u8 tx_sched_algorithm;
 	struct stmmac_rxq_cfg rx_queues_cfg[MTL_MAX_RX_QUEUES];
-- 
2.19.0

RE: [PATCH net-next v3 2/2] net: stmmac: Tx coe sw fallback

[Jose Abreu]

From: Rohan G Thomas <rohan.g.thomas@intel.com>
Date: Mon, Aug 14, 2023 at 15:06:37

> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
> @@ -219,6 +219,8 @@ struct stmmac_priv {
>  	int hwts_tx_en;
>  	bool tx_path_in_lpi_mode;
>  	bool tso;
> +	bool tx_q_coe_lmt;

Please use a flag here instead of "tx_q_coe_lmt". This is the preferrable method now.

Thanks,
Jose

> +	u32 tx_q_with_coe;
>  	int sph;
>  	int sph_cap;
>  	u32 sarc_type;

RE: [PATCH net-next v3 2/2] net: stmmac: Tx coe sw fallback

[rohan.g.thomas]

From: Rohan G Thomas <rohan.g.thomas@intel.com>

From: Rohan G Thomas <rohan.g.thomas@intel.com>
Date: Mon, Aug 14, 2023 at 15:06:37
> 
> > --- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
> > +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
> > @@ -219,6 +219,8 @@ struct stmmac_priv {
> >  	int hwts_tx_en;
> >  	bool tx_path_in_lpi_mode;
> >  	bool tso;
> > +	bool tx_q_coe_lmt;
> 
> Please use a flag here instead of "tx_q_coe_lmt". This is the preferrable
> method now.
> 
> Thanks,
> Jose

Thanks Jose for the feedback. If I read that correctly, your
suggestion is to change " tx_q_coe_lmt" to something more readable,
like "has_txcoe_limit". Please correct me if I understand it wrongly.

BR,
Rohan

> 
> > +	u32 tx_q_with_coe;
> >  	int sph;
> >  	int sph_cap;
> >  	u32 sarc_type;

RE: [PATCH net-next v3 2/2] net: stmmac: Tx coe sw fallback

[Rohan G Thomas]

From: Rohan G Thomas <rohan.g.thomas@intel.com>
Date: Mon, Aug 14, 2023 at 15:06:37
> > > +	bool tx_q_coe_lmt;
> >
> > Please use a flag here instead of "tx_q_coe_lmt". This is the
> > preferrable method now.
> >
> > Thanks,
> > Jose
> 
> Thanks Jose for the feedback. If I read that correctly, your suggestion is to
> change " tx_q_coe_lmt" to something more readable, like "has_txcoe_limit".
> Please correct me if I understand it wrongly.
> 
> BR,
> Rohan
>

Or, use int instead of bool?

BR,
Rohan

RE: [PATCH net-next v3 2/2] net: stmmac: Tx coe sw fallback

[Jose Abreu]

From: Rohan G Thomas <rohan.g.thomas@intel.com>
Date: Tue, Aug 15, 2023 at 04:51:45

> From: Rohan G Thomas <rohan.g.thomas@intel.com>
> Date: Mon, Aug 14, 2023 at 15:06:37
> > > > +	bool tx_q_coe_lmt;
> > >
> > > Please use a flag here instead of "tx_q_coe_lmt". This is the
> > > preferrable method now.
> > >
> > > Thanks,
> > > Jose
> > 
> > Thanks Jose for the feedback. If I read that correctly, your suggestion is to
> > change " tx_q_coe_lmt" to something more readable, like "has_txcoe_limit".
> > Please correct me if I understand it wrongly.
> > 
> > BR,
> > Rohan
> >
> 
> Or, use int instead of bool?

No, I mean to replace it with a bit flag as it was done on https://lore.kernel.org/all/20230710090001.303225-1-brgl@bgdev.pl/.

Thanks,
Jose