Re: [RFC 3/7] net: ethernet: mtk_eth_soc: implement flow offloading to WED devices

[Felix Fietkau <nbd@nbd.name>]

On 2021-07-13 20:56, Pablo Neira Ayuso wrote:
> On Tue, Jul 13, 2021 at 06:07:41PM +0200, Felix Fietkau wrote:
>> This allows hardware flow offloading from Ethernet to WLAN on MT7622 SoC
>> 
>> Signed-off-by: Felix Fietkau <nbd@nbd.name>
>> ---
>>  drivers/net/ethernet/mediatek/mtk_ppe.c       | 18 +++++
>>  drivers/net/ethernet/mediatek/mtk_ppe.h       | 14 ++--
>>  .../net/ethernet/mediatek/mtk_ppe_offload.c   | 67 ++++++++++++-------
>>  include/linux/netdevice.h                     |  7 ++
>>  net/core/dev.c                                |  4 ++
>>  5 files changed, 78 insertions(+), 32 deletions(-)
>> 
>> diff --git a/drivers/net/ethernet/mediatek/mtk_ppe.c b/drivers/net/ethernet/mediatek/mtk_ppe.c
>> index 3ad10c793308..472bcd3269a7 100644
>> --- a/drivers/net/ethernet/mediatek/mtk_ppe.c
>> +++ b/drivers/net/ethernet/mediatek/mtk_ppe.c
>> @@ -329,6 +329,24 @@ int mtk_foe_entry_set_pppoe(struct mtk_foe_entry *entry, int sid)
>>  	return 0;
>>  }
>>  
>> +int mtk_foe_entry_set_wdma(struct mtk_foe_entry *entry, int wdma_idx, int txq,
>> +			   int bss, int wcid)
>> +{
>> +	struct mtk_foe_mac_info *l2 = mtk_foe_entry_l2(entry);
>> +	u32 *ib2 = mtk_foe_entry_ib2(entry);
>> +
>> +	*ib2 &= ~MTK_FOE_IB2_PORT_MG;
>> +	*ib2 |= MTK_FOE_IB2_WDMA_WINFO;
>> +	if (wdma_idx)
>> +		*ib2 |= MTK_FOE_IB2_WDMA_DEVIDX;
>> +
>> +	l2->vlan2 = FIELD_PREP(MTK_FOE_VLAN2_WINFO_BSS, bss) |
>> +		    FIELD_PREP(MTK_FOE_VLAN2_WINFO_WCID, wcid) |
>> +		    FIELD_PREP(MTK_FOE_VLAN2_WINFO_RING, txq);
>> +
>> +	return 0;
>> +}
>> +
>>  static inline bool mtk_foe_entry_usable(struct mtk_foe_entry *entry)
>>  {
>>  	return !(entry->ib1 & MTK_FOE_IB1_STATIC) &&
>> diff --git a/drivers/net/ethernet/mediatek/mtk_ppe.h b/drivers/net/ethernet/mediatek/mtk_ppe.h
>> index 242fb8f2ae65..df8ccaf48171 100644
>> --- a/drivers/net/ethernet/mediatek/mtk_ppe.h
>> +++ b/drivers/net/ethernet/mediatek/mtk_ppe.h
>> @@ -48,9 +48,9 @@ enum {
>>  #define MTK_FOE_IB2_DEST_PORT		GENMASK(7, 5)
>>  #define MTK_FOE_IB2_MULTICAST		BIT(8)
>>  
>> -#define MTK_FOE_IB2_WHNAT_QID2		GENMASK(13, 12)
>> -#define MTK_FOE_IB2_WHNAT_DEVIDX	BIT(16)
>> -#define MTK_FOE_IB2_WHNAT_NAT		BIT(17)
>> +#define MTK_FOE_IB2_WDMA_QID2		GENMASK(13, 12)
>> +#define MTK_FOE_IB2_WDMA_DEVIDX		BIT(16)
>> +#define MTK_FOE_IB2_WDMA_WINFO		BIT(17)
>>  
>>  #define MTK_FOE_IB2_PORT_MG		GENMASK(17, 12)
>>  
>> @@ -58,9 +58,9 @@ enum {
>>  
>>  #define MTK_FOE_IB2_DSCP		GENMASK(31, 24)
>>  
>> -#define MTK_FOE_VLAN2_WHNAT_BSS		GEMMASK(5, 0)
>> -#define MTK_FOE_VLAN2_WHNAT_WCID	GENMASK(13, 6)
>> -#define MTK_FOE_VLAN2_WHNAT_RING	GENMASK(15, 14)
>> +#define MTK_FOE_VLAN2_WINFO_BSS		GENMASK(5, 0)
>> +#define MTK_FOE_VLAN2_WINFO_WCID	GENMASK(13, 6)
>> +#define MTK_FOE_VLAN2_WINFO_RING	GENMASK(15, 14)
>>  
>>  enum {
>>  	MTK_FOE_STATE_INVALID,
>> @@ -281,6 +281,8 @@ int mtk_foe_entry_set_ipv6_tuple(struct mtk_foe_entry *entry,
>>  int mtk_foe_entry_set_dsa(struct mtk_foe_entry *entry, int port);
>>  int mtk_foe_entry_set_vlan(struct mtk_foe_entry *entry, int vid);
>>  int mtk_foe_entry_set_pppoe(struct mtk_foe_entry *entry, int sid);
>> +int mtk_foe_entry_set_wdma(struct mtk_foe_entry *entry, int wdma_idx, int txq,
>> +			   int bss, int wcid);
>>  int mtk_foe_entry_commit(struct mtk_ppe *ppe, struct mtk_foe_entry *entry,
>>  			 u16 timestamp);
>>  int mtk_ppe_debugfs_init(struct mtk_ppe *ppe);
>> diff --git a/drivers/net/ethernet/mediatek/mtk_ppe_offload.c b/drivers/net/ethernet/mediatek/mtk_ppe_offload.c
>> index b5f68f66d42a..00b1d06f60d1 100644
>> --- a/drivers/net/ethernet/mediatek/mtk_ppe_offload.c
>> +++ b/drivers/net/ethernet/mediatek/mtk_ppe_offload.c
>> @@ -10,6 +10,7 @@
>>  #include <net/pkt_cls.h>
>>  #include <net/dsa.h>
>>  #include "mtk_eth_soc.h"
>> +#include "mtk_wed.h"
>>  
>>  struct mtk_flow_data {
>>  	struct ethhdr eth;
>> @@ -39,6 +40,7 @@ struct mtk_flow_entry {
>>  	struct rhash_head node;
>>  	unsigned long cookie;
>>  	u16 hash;
>> +	s8 wed_index;
>>  };
>>  
>>  static const struct rhashtable_params mtk_flow_ht_params = {
>> @@ -127,35 +129,38 @@ mtk_flow_mangle_ipv4(const struct flow_action_entry *act,
>>  }
>>  
>>  static int
>> -mtk_flow_get_dsa_port(struct net_device **dev)
>> +mtk_flow_set_output_device(struct mtk_eth *eth, struct mtk_foe_entry *foe,
>> +			   struct net_device *dev, const u8 *dest_mac,
>> +			   int *wed_index)
>>  {
>> -#if IS_ENABLED(CONFIG_NET_DSA)
>> -	struct dsa_port *dp;
>> -
>> -	dp = dsa_port_from_netdev(*dev);
>> -	if (IS_ERR(dp))
>> -		return -ENODEV;
>> -
>> -	if (dp->cpu_dp->tag_ops->proto != DSA_TAG_PROTO_MTK)
>> -		return -ENODEV;
>> +	struct net_device_path_ctx ctx = {
>> +		.dev    = dev,
>> +		.daddr  = dest_mac,
>> +	};
>> +	struct net_device_path path = {};
>> +	int pse_port;
>>  
>> -	*dev = dp->cpu_dp->master;
>> +	if (!dev->netdev_ops->ndo_fill_forward_path ||
>> +	    dev->netdev_ops->ndo_fill_forward_path(&ctx, &path) < 0)
>> +		path.type = DEV_PATH_ETHERNET;
> 
> Maybe expose this through flow offload API so there is no need to call
> ndo_fill_forward_path again from the driver?
Can you give me a pseudo-code example? I'm not sure how you want it to
be exposed through the flow offload API.
To me it seems easier and cleaner to just have a single
ndo_fill_forward_path call for the final output device to check the
device types that don't have any corresponding sw offload.

>> -	return dp->index;
>> -#else
>> -	return -ENODEV;
>> -#endif
>> -}
>> -
>> -static int
>> -mtk_flow_set_output_device(struct mtk_eth *eth, struct mtk_foe_entry *foe,
>> -			   struct net_device *dev)
>> -{
>> -	int pse_port, dsa_port;
>> +	switch (path.type) {
>> +	case DEV_PATH_DSA:
> 
> This DSA update is not related, right?
I consider it related. Since I'm calling ndo_fill_forward_path now, it's
better to use it for both DSA and WLAN instead of having independent checks.

- Felix