[PATCH net-next v6 0/2] net: stmmac: Tx coe sw fallback

[PATCH net-next v6 0/2] net: stmmac: Tx coe sw fallback

[Rohan G Thomas]

Hi,
DW xGMAC IP can be synthesized such that it can support tx checksum
offloading only for a few initial tx queues. Also as Serge pointed
out, for the DW QoS IP, tx coe can be individually configured for
each tx queue. This patchset adds support for tx coe sw fallback for
those queues that don't support tx coe. Also, add binding for
snps,coe-unsupported property.

changelog v6:
* Reworked patchset to cover DW QoS Ethernet IP also.

changelog v5:
* As rightly suggested by Serge, reworked redundant code.

changelog v4: 
* Replaced tx_q_coe_lmt with bit flag.

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 coe unsupported
  net: stmmac: Tx coe sw fallback

 Documentation/devicetree/bindings/net/snps,dwmac.yaml |  3 +++
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c     | 10 ++++++++++
 drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c |  3 +++
 include/linux/stmmac.h                                |  1 +
 4 files changed, 17 insertions(+)

-- 
2.25.1

[PATCH net-next v6 1/2] dt-bindings: net: snps,dwmac: Tx coe unsupported

[Rohan G Thomas]

Add dt-bindings for coe-unsupported property per tx queue.

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..365e6cb73484 100644
--- a/Documentation/devicetree/bindings/net/snps,dwmac.yaml
+++ b/Documentation/devicetree/bindings/net/snps,dwmac.yaml
@@ -394,6 +394,9 @@ properties:
               When a PFC frame is received with priorities matching the bitmask,
               the queue is blocked from transmitting for the pause time specified
               in the PFC frame.
+          snps,coe-unsupported:
+            type: boolean
+            description: TX checksum offload is unsupported by the TX queue.
         allOf:
           - if:
               required:
-- 
2.25.1

[PATCH net-next v6 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. DW xGMAC IP can be synthesized
such that it can support tx checksum offloading only for a few
initial tx queues. Also as Serge pointed out, for the DW QoS IP, tx
coe can be individually configured for each tx queue.

So when tx coe is enabled, for any tx queue that doesn't support
tx coe with 'coe-unsupported' flag set will have a sw fallback
happen in the driver for tx checksum calculation when any packets to
be transmitted on these tx queues.

Signed-off-by: Rohan G Thomas <rohan.g.thomas@intel.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c     | 10 ++++++++++
 drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c |  3 +++
 include/linux/stmmac.h                                |  1 +
 3 files changed, 14 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 2206789802bf..9201ed778ebc 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -4401,6 +4401,16 @@ 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);
+	/* DWMAC IPs can be synthesized to support tx coe only for a few tx
+	 * queues. In that case, checksum offloading for those queues that don't
+	 * support tx coe needs to fallback to software checksum calculation.
+	 */
+	if (csum_insertion &&
+	    priv->plat->tx_queues_cfg[queue].coe_unsupported) {
+		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);
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
index 0f28795e581c..a09014c9e7d0 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
@@ -276,6 +276,9 @@ static int stmmac_mtl_setup(struct platform_device *pdev,
 			plat->tx_queues_cfg[queue].use_prio = true;
 		}
 
+		plat->tx_queues_cfg[queue].coe_unsupported =
+			of_property_read_bool(q_node, "snps,coe-unsupported");
+
 		queue++;
 	}
 	if (queue != plat->tx_queues_to_use) {
diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index ce89cc3e4913..c0079a7574ae 100644
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h
@@ -139,6 +139,7 @@ struct stmmac_rxq_cfg {
 
 struct stmmac_txq_cfg {
 	u32 weight;
+	bool coe_unsupported;
 	u8 mode_to_use;
 	/* Credit Base Shaper parameters */
 	u32 send_slope;
-- 
2.25.1

Re: [PATCH net-next v6 1/2] dt-bindings: net: snps,dwmac: Tx coe unsupported

[Rob Herring]

On Fri, Sep 15, 2023 at 05:54:16PM +0800, Rohan G Thomas wrote:
> Add dt-bindings for coe-unsupported property per tx queue.

Why? (What every commit msg should answer)

> 
> 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..365e6cb73484 100644
> --- a/Documentation/devicetree/bindings/net/snps,dwmac.yaml
> +++ b/Documentation/devicetree/bindings/net/snps,dwmac.yaml
> @@ -394,6 +394,9 @@ properties:
>                When a PFC frame is received with priorities matching the bitmask,
>                the queue is blocked from transmitting for the pause time specified
>                in the PFC frame.

blank line needed

> +          snps,coe-unsupported:
> +            type: boolean
> +            description: TX checksum offload is unsupported by the TX queue.

And here.

>          allOf:
>            - if:
>                required:
> -- 
> 2.25.1
> 

Re: [linux-drivers-review] [PATCH net-next v2 1/3] net: stmmac: xgmac: EST interrupts handling

[rohan.g.thomas]

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

Thanks for the review comments.
Will address this in the next version.

On Fri, Sep 15, 2023 at 05:54:16PM +0800, Rohan G Thomas wrote:
>> Add dt-bindings for coe-unsupported property per tx queue.
>
>Why? (What every commit msg should answer)
>
>> 
>> 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..365e6cb73484 100644
>> --- a/Documentation/devicetree/bindings/net/snps,dwmac.yaml
>> +++ b/Documentation/devicetree/bindings/net/snps,dwmac.yaml
>> @@ -394,6 +394,9 @@ properties:
>>                When a PFC frame is received with priorities matching the bitmask,
>>                the queue is blocked from transmitting for the pause time specified
>>                in the PFC frame.
>
>blank line needed
>
>> +          snps,coe-unsupported:
>> +            type: boolean
>> +            description: TX checksum offload is unsupported by the TX queue.
>
>And here.
>
>>          allOf:
>>            - if:
>>                required:
>> -- 
>> 2.25.1
>>