[PATCH net-next v2 0/3] net: qualcomm: rmnet: Enable Mapv5

[PATCH net-next v2 0/3] net: qualcomm: rmnet: Enable Mapv5

[Sharath Chandra Vurukala]

This series introduces the MAPv5 packet format.

Patch 0 documents the MAPv5.
Patch 1 introduces the Mapv5 and the Inline checksum offload for RX.
Patch 2 introduces the Mapv5 and the Inline checksum offload for TX.

A new checksum header format is used as part of MAPv5.
For RX checksum offload, the checksum is verified by the HW and the validity is marked in the checksum header of MAPv5.
for TX, the required metadata is filled up so hardware can compute the checksum.

v1->v2:
- Fixed the compilation errors, warnings reported by kernel test robot.
- Checksum header definition is expanded to support big, little endian formats as mentioned by Jakub.

Sharath Chandra Vurukala (3):
  docs: networking: Add documentation for MAPv5
  net: ethernet: rmnet: Support for downlink MAPv5 checksum offload
  net: ethernet: rmnet: Add support for Mapv5 uplink packet

 .../device_drivers/cellular/qualcomm/rmnet.rst     |  53 ++++++-
 drivers/net/ethernet/qualcomm/rmnet/rmnet_config.h |   4 +-
 .../net/ethernet/qualcomm/rmnet/rmnet_handlers.c   |  34 +++--
 drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h    |  22 ++-
 .../net/ethernet/qualcomm/rmnet/rmnet_map_data.c   | 153 ++++++++++++++++++++-
 include/linux/if_rmnet.h                           |  24 +++-
 include/uapi/linux/if_link.h                       |   2 +
 7 files changed, 263 insertions(+), 29 deletions(-)

-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH net-next v2 1/3] docs: networking: Add documentation for MAPv5

[Sharath Chandra Vurukala]

Adding documentation explaining the new MAPv5 packet format
and the corresponding checksum offload header.

Signed-off-by: Sharath Chandra Vurukala <sharathv@codeaurora.org>
---
 .../device_drivers/cellular/qualcomm/rmnet.rst     | 53 ++++++++++++++++++++--
 1 file changed, 49 insertions(+), 4 deletions(-)

diff --git a/Documentation/networking/device_drivers/cellular/qualcomm/rmnet.rst b/Documentation/networking/device_drivers/cellular/qualcomm/rmnet.rst
index 70643b5..8c81f19 100644
--- a/Documentation/networking/device_drivers/cellular/qualcomm/rmnet.rst
+++ b/Documentation/networking/device_drivers/cellular/qualcomm/rmnet.rst
@@ -27,7 +27,7 @@ these MAP frames and send them to appropriate PDN's.
 2. Packet format
 ================
 
-a. MAP packet (data / control)
+a. MAP packet v1 (data / control)
 
 MAP header has the same endianness of the IP packet.
 
@@ -35,8 +35,9 @@ Packet format::
 
   Bit             0             1           2-7      8 - 15           16 - 31
   Function   Command / Data   Reserved     Pad   Multiplexer ID    Payload length
-  Bit            32 - x
-  Function     Raw  Bytes
+
+  Bit            32-x
+  Function      Raw bytes
 
 Command (1)/ Data (0) bit value is to indicate if the packet is a MAP command
 or data packet. Control packet is used for transport level flow control. Data
@@ -52,7 +53,51 @@ Multiplexer ID is to indicate the PDN on which data has to be sent.
 Payload length includes the padding length but does not include MAP header
 length.
 
-b. MAP packet (command specific)::
+b. MAP packet v5 (data / control)
+
+MAP header has the same endianness of the IP packet.
+
+Packet format::
+
+  Bit             0             1         2-7      8 - 15           16 - 31
+  Function   Command / Data  Next Header  Pad   Multiplexer ID   Payload length
+
+  Bit            32 - 38        1               40              41-63
+  Function     Header Type    Next Header     Checksum Valid    Reserved
+
+  Bit            64-x
+  Function      Raw bytes
+
+Command (1)/ Data (0) bit value is to indicate if the packet is a MAP command
+or data packet. Control packet is used for transport level flow control. Data
+packets are standard IP packets.
+
+Next header is used to indicate the presence of another header, currently is
+limited to checksum header.
+
+Padding is number of bytes to be added for 4 byte alignment if required by
+hardware.
+
+Multiplexer ID is to indicate the PDN on which data has to be sent.
+
+Payload length includes the padding length but does not include MAP header
+length.
+
+Header Type is to indicate the type of header, this usually is set to CHECKSUM
+
+Header types
+= ==========================================
+0 Reserved
+1 Reserved
+2 checksum header
+
+Checksum Valid is to indicate whether the header checksum is valid. Value of 1
+implies that checksum is calculated on this packet and is valid, value of 0
+indicates that the calculated packet checksum is invalid.
+
+Reserved bits are usually zeroed out and to be ignored by receiver.
+
+c. MAP packet v1/v5 (command specific)::
 
     Bit             0             1           2-7      8 - 15           16 - 31
     Function   Command         Reserved     Pad   Multiplexer ID    Payload length
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH net-next v2 2/3] net: ethernet: rmnet: Support for downlink MAPv5 checksum offload

[Sharath Chandra Vurukala]

Adding support for processing of Mapv5 downlink packets.
It involves parsing the Mapv5 packet and checking the csum header
to know whether the hardware has validated the checksum and is
valid or not.

Based on the checksum valid bit the corresponding stats are
incremented and skb->ip_summed is marked either CHECKSUM_UNNECESSARY
or left as CHEKSUM_NONE to let network stack revalidated the checksum
and update the respective snmp stats.

Current MapV1 header has been modified, the reserved field in the
Mapv1 header is now used for next header indication.

Signed-off-by: Sharath Chandra Vurukala <sharathv@codeaurora.org>
---
 .../net/ethernet/qualcomm/rmnet/rmnet_handlers.c   | 19 ++++---
 drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h    | 14 ++++-
 .../net/ethernet/qualcomm/rmnet/rmnet_map_data.c   | 60 +++++++++++++++++++++-
 include/linux/if_rmnet.h                           | 24 +++++++--
 include/uapi/linux/if_link.h                       |  1 +
 5 files changed, 106 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c
index 3d7d3ab..70ad6a7 100644
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0-only
-/* Copyright (c) 2013-2018, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2013-2018, 2021, The Linux Foundation. All rights reserved.
  *
  * RMNET Data ingress/egress handler
  */
@@ -57,8 +57,8 @@ __rmnet_map_ingress_handler(struct sk_buff *skb,
 			    struct rmnet_port *port)
 {
 	struct rmnet_endpoint *ep;
+	u8 mux_id, next_hdr;
 	u16 len, pad;
-	u8 mux_id;
 
 	if (RMNET_MAP_GET_CD_BIT(skb)) {
 		if (port->data_format & RMNET_FLAGS_INGRESS_MAP_COMMANDS)
@@ -70,6 +70,7 @@ __rmnet_map_ingress_handler(struct sk_buff *skb,
 	mux_id = RMNET_MAP_GET_MUX_ID(skb);
 	pad = RMNET_MAP_GET_PAD(skb);
 	len = RMNET_MAP_GET_LENGTH(skb) - pad;
+	next_hdr = RMNET_MAP_GET_NH_BIT(skb);
 
 	if (mux_id >= RMNET_MAX_LOGICAL_EP)
 		goto free_skb;
@@ -80,15 +81,19 @@ __rmnet_map_ingress_handler(struct sk_buff *skb,
 
 	skb->dev = ep->egress_dev;
 
-	/* Subtract MAP header */
-	skb_pull(skb, sizeof(struct rmnet_map_header));
-	rmnet_set_skb_proto(skb);
-
-	if (port->data_format & RMNET_FLAGS_INGRESS_MAP_CKSUMV4) {
+	if (next_hdr &&
+	    (port->data_format & (RMNET_FLAGS_INGRESS_MAP_CKSUMV5))) {
+		if (rmnet_map_process_next_hdr_packet(skb, len))
+			goto free_skb;
+	} else if (port->data_format & RMNET_FLAGS_INGRESS_MAP_CKSUMV4) {
 		if (!rmnet_map_checksum_downlink_packet(skb, len + pad))
 			skb->ip_summed = CHECKSUM_UNNECESSARY;
 	}
 
+	/* Subtract MAP header */
+	skb_pull(skb, sizeof(struct rmnet_map_header));
+	rmnet_set_skb_proto(skb);
+
 	skb_trim(skb, len);
 	rmnet_deliver_skb(skb);
 	return;
diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h
index 576501d..2ee1ce2 100644
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h
@@ -1,5 +1,5 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
-/* Copyright (c) 2013-2018, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2013-2018, 2021, The Linux Foundation. All rights reserved.
  */
 
 #ifndef _RMNET_MAP_H_
@@ -23,6 +23,12 @@ struct rmnet_map_control_command {
 	};
 }  __aligned(1);
 
+enum rmnet_map_v5_header_type {
+	RMNET_MAP_HEADER_TYPE_UNKNOWN,
+	RMNET_MAP_HEADER_TYPE_CSUM_OFFLOAD = 0x2,
+	RMNET_MAP_HEADER_TYPE_ENUM_LENGTH
+};
+
 enum rmnet_map_commands {
 	RMNET_MAP_COMMAND_NONE,
 	RMNET_MAP_COMMAND_FLOW_DISABLE,
@@ -44,6 +50,9 @@ enum rmnet_map_commands {
 #define RMNET_MAP_GET_LENGTH(Y) (ntohs(((struct rmnet_map_header *) \
 					(Y)->data)->pkt_len))
 
+#define RMNET_MAP_GET_NH_BIT(Y)  (((struct rmnet_map_header *) \
+				    (Y)->data)->next_hdr)
+
 #define RMNET_MAP_COMMAND_REQUEST     0
 #define RMNET_MAP_COMMAND_ACK         1
 #define RMNET_MAP_COMMAND_UNSUPPORTED 2
@@ -60,5 +69,8 @@ void rmnet_map_command(struct sk_buff *skb, struct rmnet_port *port);
 int rmnet_map_checksum_downlink_packet(struct sk_buff *skb, u16 len);
 void rmnet_map_checksum_uplink_packet(struct sk_buff *skb,
 				      struct net_device *orig_dev);
+int rmnet_map_process_next_hdr_packet(struct sk_buff *skb, u16 len);
+u8 rmnet_map_get_next_hdr_type(struct sk_buff *skb);
+bool rmnet_map_get_csum_valid(struct sk_buff *skb);
 
 #endif /* _RMNET_MAP_H_ */
diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c
index 21d3816..a3dc220 100644
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0-only
-/* Copyright (c) 2013-2018, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2013-2018, 2021, The Linux Foundation. All rights reserved.
  *
  * RMNET Data MAP protocol
  */
@@ -311,6 +311,7 @@ struct rmnet_map_header *rmnet_map_add_map_header(struct sk_buff *skb,
 struct sk_buff *rmnet_map_deaggregate(struct sk_buff *skb,
 				      struct rmnet_port *port)
 {
+	unsigned char *data = skb->data, *next_hdr = NULL;
 	struct rmnet_map_header *maph;
 	struct sk_buff *skbn;
 	u32 packet_len;
@@ -323,6 +324,12 @@ struct sk_buff *rmnet_map_deaggregate(struct sk_buff *skb,
 
 	if (port->data_format & RMNET_FLAGS_INGRESS_MAP_CKSUMV4)
 		packet_len += sizeof(struct rmnet_map_dl_csum_trailer);
+	else if (port->data_format & RMNET_FLAGS_INGRESS_MAP_CKSUMV5) {
+		if (!maph->cd_bit) {
+			packet_len += sizeof(struct rmnet_map_v5_csum_header);
+			next_hdr = data + sizeof(*maph);
+		}
+	}
 
 	if (((int)skb->len - (int)packet_len) < 0)
 		return NULL;
@@ -331,6 +338,11 @@ struct sk_buff *rmnet_map_deaggregate(struct sk_buff *skb,
 	if (ntohs(maph->pkt_len) == 0)
 		return NULL;
 
+	if (next_hdr &&
+	    ((struct rmnet_map_v5_csum_header *)next_hdr)->header_type !=
+	     RMNET_MAP_HEADER_TYPE_CSUM_OFFLOAD)
+		return NULL;
+
 	skbn = alloc_skb(packet_len + RMNET_MAP_DEAGGR_SPACING, GFP_ATOMIC);
 	if (!skbn)
 		return NULL;
@@ -428,3 +440,49 @@ void rmnet_map_checksum_uplink_packet(struct sk_buff *skb,
 
 	priv->stats.csum_sw++;
 }
+
+u8 rmnet_map_get_next_hdr_type(struct sk_buff *skb)
+{
+	unsigned char *data = skb->data;
+
+	data += sizeof(struct rmnet_map_header);
+	return ((struct rmnet_map_v5_csum_header *)data)->header_type;
+}
+
+bool rmnet_map_get_csum_valid(struct sk_buff *skb)
+{
+	unsigned char *data = skb->data;
+
+	data += sizeof(struct rmnet_map_header);
+	return ((struct rmnet_map_v5_csum_header *)data)->csum_valid_required;
+}
+
+/* Process a MAPv5 packet header */
+int rmnet_map_process_next_hdr_packet(struct sk_buff *skb,
+				      u16 len)
+{
+	struct rmnet_priv *priv = netdev_priv(skb->dev);
+	int rc = 0;
+
+	switch (rmnet_map_get_next_hdr_type(skb)) {
+	case RMNET_MAP_HEADER_TYPE_CSUM_OFFLOAD:
+		if (unlikely(!(skb->dev->features & NETIF_F_RXCSUM))) {
+			priv->stats.csum_sw++;
+		} else if (rmnet_map_get_csum_valid(skb)) {
+			priv->stats.csum_ok++;
+			skb->ip_summed = CHECKSUM_UNNECESSARY;
+		} else {
+			priv->stats.csum_valid_unset++;
+		}
+
+		/* Pull csum v5 header */
+		skb_pull(skb, sizeof(struct rmnet_map_v5_csum_header));
+		break;
+	default:
+		rc = -EINVAL;
+		break;
+	}
+
+	return rc;
+}
+
diff --git a/include/linux/if_rmnet.h b/include/linux/if_rmnet.h
index 9661416..a6de521 100644
--- a/include/linux/if_rmnet.h
+++ b/include/linux/if_rmnet.h
@@ -1,5 +1,5 @@
 /* SPDX-License-Identifier: GPL-2.0-only
- * Copyright (c) 2013-2019, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2013-2019, 2021 The Linux Foundation. All rights reserved.
  */
 
 #ifndef _LINUX_IF_RMNET_H_
@@ -8,11 +8,11 @@
 struct rmnet_map_header {
 #if defined(__LITTLE_ENDIAN_BITFIELD)
 	u8  pad_len:6;
-	u8  reserved_bit:1;
+	u8  next_hdr:1;
 	u8  cd_bit:1;
 #elif defined (__BIG_ENDIAN_BITFIELD)
 	u8  cd_bit:1;
-	u8  reserved_bit:1;
+	u8  next_hdr:1;
 	u8  pad_len:6;
 #else
 #error	"Please fix <asm/byteorder.h>"
@@ -52,4 +52,22 @@ struct rmnet_map_ul_csum_header {
 #endif
 } __aligned(1);
 
+/* MAP CSUM headers */
+struct rmnet_map_v5_csum_header {
+#if defined(__LITTLE_ENDIAN_BITFIELD)
+	u8  next_hdr:1;
+	u8  header_type:7;
+	u8  hw_reserved:7;
+	u8  csum_valid_required:1;
+#elif defined(__BIG_ENDIAN_BITFIELD)
+	u8  header_type:7;
+	u8  next_hdr:1;
+	u8  csum_valid_required:1
+	u8  hw_reserved:7;
+#else
+#error	"Please fix <asm/byteorder.h>"
+#endif
+	__be16 reserved;
+} __aligned(1);
+
 #endif /* !(_LINUX_IF_RMNET_H_) */
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index 82708c6..838bd29 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -1233,6 +1233,7 @@ enum {
 #define RMNET_FLAGS_INGRESS_MAP_COMMANDS          (1U << 1)
 #define RMNET_FLAGS_INGRESS_MAP_CKSUMV4           (1U << 2)
 #define RMNET_FLAGS_EGRESS_MAP_CKSUMV4            (1U << 3)
+#define RMNET_FLAGS_INGRESS_MAP_CKSUMV5           (1U << 4)
 
 enum {
 	IFLA_RMNET_UNSPEC,
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH net-next v2 3/3] net: ethernet: rmnet: Add support for Mapv5 uplink packet

[Sharath Chandra Vurukala]

Adding Support for Mapv5 uplink packet.
Based on the configuration, request HW for csum offload,
by setting the csum_valid_required of Mapv5 packet.

Signed-off-by: Sharath Chandra Vurukala <sharathv@codeaurora.org>
---
 drivers/net/ethernet/qualcomm/rmnet/rmnet_config.h |  4 +-
 .../net/ethernet/qualcomm/rmnet/rmnet_handlers.c   | 15 +++-
 drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h    |  8 +-
 .../net/ethernet/qualcomm/rmnet/rmnet_map_data.c   | 93 ++++++++++++++++++++--
 include/uapi/linux/if_link.h                       |  1 +
 5 files changed, 108 insertions(+), 13 deletions(-)

diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.h b/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.h
index 8d8d469..8e64ca9 100644
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.h
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.h
@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
-/* Copyright (c) 2013-2014, 2016-2018 The Linux Foundation. All rights reserved.
+/* Copyright (c) 2013-2014, 2016-2018, 2021 The Linux Foundation.
+ * All rights reserved.
  *
  * RMNET Data configuration engine
  */
@@ -56,6 +57,7 @@ struct rmnet_priv_stats {
 	u64 csum_fragmented_pkt;
 	u64 csum_skipped;
 	u64 csum_sw;
+	u64 csum_hw;
 };
 
 struct rmnet_priv {
diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c
index 70ad6a7..e6a44cd 100644
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c
@@ -131,26 +131,33 @@ static int rmnet_map_egress_handler(struct sk_buff *skb,
 				    struct rmnet_port *port, u8 mux_id,
 				    struct net_device *orig_dev)
 {
-	int required_headroom, additional_header_len;
+	int required_headroom, additional_header_len, csum_type;
 	struct rmnet_map_header *map_header;
 
+	csum_type = 0;
 	additional_header_len = 0;
 	required_headroom = sizeof(struct rmnet_map_header);
 
 	if (port->data_format & RMNET_FLAGS_EGRESS_MAP_CKSUMV4) {
 		additional_header_len = sizeof(struct rmnet_map_ul_csum_header);
 		required_headroom += additional_header_len;
+		csum_type = RMNET_FLAGS_EGRESS_MAP_CKSUMV4;
+	} else if (port->data_format & RMNET_FLAGS_EGRESS_MAP_CKSUMV5) {
+		additional_header_len = sizeof(struct rmnet_map_v5_csum_header);
+		csum_type = RMNET_FLAGS_EGRESS_MAP_CKSUMV5;
 	}
 
+	required_headroom += additional_header_len;
+
 	if (skb_headroom(skb) < required_headroom) {
 		if (pskb_expand_head(skb, required_headroom, 0, GFP_ATOMIC))
 			return -ENOMEM;
 	}
 
-	if (port->data_format & RMNET_FLAGS_EGRESS_MAP_CKSUMV4)
-		rmnet_map_checksum_uplink_packet(skb, orig_dev);
+	if (csum_type)
+		rmnet_map_checksum_uplink_packet(skb, port, orig_dev, csum_type);
 
-	map_header = rmnet_map_add_map_header(skb, additional_header_len, 0);
+	map_header = rmnet_map_add_map_header(skb, additional_header_len, port, 0);
 	if (!map_header)
 		return -ENOMEM;
 
diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h
index 2ee1ce2..84d108e 100644
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h
@@ -64,11 +64,15 @@ enum rmnet_map_commands {
 struct sk_buff *rmnet_map_deaggregate(struct sk_buff *skb,
 				      struct rmnet_port *port);
 struct rmnet_map_header *rmnet_map_add_map_header(struct sk_buff *skb,
-						  int hdrlen, int pad);
+						  int hdrlen,
+						  struct rmnet_port *port,
+						  int pad);
 void rmnet_map_command(struct sk_buff *skb, struct rmnet_port *port);
 int rmnet_map_checksum_downlink_packet(struct sk_buff *skb, u16 len);
 void rmnet_map_checksum_uplink_packet(struct sk_buff *skb,
-				      struct net_device *orig_dev);
+				      struct rmnet_port *port,
+				      struct net_device *orig_dev,
+				      int csum_type);
 int rmnet_map_process_next_hdr_packet(struct sk_buff *skb, u16 len);
 u8 rmnet_map_get_next_hdr_type(struct sk_buff *skb);
 bool rmnet_map_get_csum_valid(struct sk_buff *skb);
diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c
index a3dc220..f65bdd4 100644
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c
@@ -263,12 +263,69 @@ rmnet_map_ipv6_ul_csum_header(void *ip6hdr,
 }
 #endif
 
+static void rmnet_map_v5_checksum_uplink_packet(struct sk_buff *skb,
+						struct rmnet_port *port,
+						struct net_device *orig_dev)
+{
+	struct rmnet_priv *priv = netdev_priv(orig_dev);
+	struct rmnet_map_v5_csum_header *ul_header;
+
+	if (!(port->data_format & RMNET_FLAGS_EGRESS_MAP_CKSUMV5))
+		return;
+
+	ul_header = (struct rmnet_map_v5_csum_header *)
+		    skb_push(skb, sizeof(*ul_header));
+	memset(ul_header, 0, sizeof(*ul_header));
+	ul_header->header_type = RMNET_MAP_HEADER_TYPE_CSUM_OFFLOAD;
+
+	if (skb->ip_summed == CHECKSUM_PARTIAL) {
+		void *iph = (char *)ul_header + sizeof(*ul_header);
+		__sum16 *check;
+		void *trans;
+		u8 proto;
+
+		if (skb->protocol == htons(ETH_P_IP)) {
+			u16 ip_len = ((struct iphdr *)iph)->ihl * 4;
+
+			proto = ((struct iphdr *)iph)->protocol;
+			trans = iph + ip_len;
+		} else if (skb->protocol == htons(ETH_P_IPV6)) {
+#if IS_ENABLED(CONFIG_IPV6)
+			u16 ip_len = sizeof(struct ipv6hdr);
+
+			proto = ((struct ipv6hdr *)iph)->nexthdr;
+			trans = iph + ip_len;
+#else
+			priv->stats.csum_err_invalid_ip_version++;
+			goto sw_csum;
+#endif /* CONFIG_IPV6 */
+		} else {
+			priv->stats.csum_err_invalid_ip_version++;
+			goto sw_csum;
+		}
+
+		check = rmnet_map_get_csum_field(proto, trans);
+		if (check) {
+			skb->ip_summed = CHECKSUM_NONE;
+			/* Ask for checksum offloading */
+			ul_header->csum_valid_required = 1;
+			priv->stats.csum_hw++;
+			return;
+		}
+	}
+
+sw_csum:
+	priv->stats.csum_sw++;
+}
+
 /* Adds MAP header to front of skb->data
  * Padding is calculated and set appropriately in MAP header. Mux ID is
  * initialized to 0.
  */
 struct rmnet_map_header *rmnet_map_add_map_header(struct sk_buff *skb,
-						  int hdrlen, int pad)
+						  int hdrlen,
+						  struct rmnet_port *port,
+						  int pad)
 {
 	struct rmnet_map_header *map_header;
 	u32 padding, map_datalen;
@@ -279,6 +336,11 @@ struct rmnet_map_header *rmnet_map_add_map_header(struct sk_buff *skb,
 			skb_push(skb, sizeof(struct rmnet_map_header));
 	memset(map_header, 0, sizeof(struct rmnet_map_header));
 
+	/* Set next_hdr bit for csum offload packets */
+	if (port->data_format & RMNET_FLAGS_EGRESS_MAP_CKSUMV5) {
+		map_header->next_hdr = 1;
+	}
+
 	if (pad == RMNET_MAP_NO_PAD_BYTES) {
 		map_header->pkt_len = htons(map_datalen);
 		return map_header;
@@ -395,11 +457,8 @@ int rmnet_map_checksum_downlink_packet(struct sk_buff *skb, u16 len)
 	return 0;
 }
 
-/* Generates UL checksum meta info header for IPv4 and IPv6 over TCP and UDP
- * packets that are supported for UL checksum offload.
- */
-void rmnet_map_checksum_uplink_packet(struct sk_buff *skb,
-				      struct net_device *orig_dev)
+static void rmnet_map_v4_checksum_uplink_packet(struct sk_buff *skb,
+						struct net_device *orig_dev)
 {
 	struct rmnet_priv *priv = netdev_priv(orig_dev);
 	struct rmnet_map_ul_csum_header *ul_header;
@@ -418,10 +477,12 @@ void rmnet_map_checksum_uplink_packet(struct sk_buff *skb,
 
 		if (skb->protocol == htons(ETH_P_IP)) {
 			rmnet_map_ipv4_ul_csum_header(iphdr, ul_header, skb);
+			priv->stats.csum_hw++;
 			return;
 		} else if (skb->protocol == htons(ETH_P_IPV6)) {
 #if IS_ENABLED(CONFIG_IPV6)
 			rmnet_map_ipv6_ul_csum_header(iphdr, ul_header, skb);
+			priv->stats.csum_hw++;
 			return;
 #else
 			priv->stats.csum_err_invalid_ip_version++;
@@ -457,6 +518,26 @@ bool rmnet_map_get_csum_valid(struct sk_buff *skb)
 	return ((struct rmnet_map_v5_csum_header *)data)->csum_valid_required;
 }
 
+/* Generates UL checksum meta info header for IPv4 and IPv6 over TCP and UDP
+ * packets that are supported for UL checksum offload.
+ */
+void rmnet_map_checksum_uplink_packet(struct sk_buff *skb,
+				      struct rmnet_port *port,
+				      struct net_device *orig_dev,
+				      int csum_type)
+{
+	switch (csum_type) {
+	case RMNET_FLAGS_EGRESS_MAP_CKSUMV4:
+		rmnet_map_v4_checksum_uplink_packet(skb, orig_dev);
+		break;
+	case RMNET_FLAGS_EGRESS_MAP_CKSUMV5:
+		rmnet_map_v5_checksum_uplink_packet(skb, port, orig_dev);
+		break;
+	default:
+		break;
+	}
+}
+
 /* Process a MAPv5 packet header */
 int rmnet_map_process_next_hdr_packet(struct sk_buff *skb,
 				      u16 len)
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index 838bd29..319865f 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -1234,6 +1234,7 @@ enum {
 #define RMNET_FLAGS_INGRESS_MAP_CKSUMV4           (1U << 2)
 #define RMNET_FLAGS_EGRESS_MAP_CKSUMV4            (1U << 3)
 #define RMNET_FLAGS_INGRESS_MAP_CKSUMV5           (1U << 4)
+#define RMNET_FLAGS_EGRESS_MAP_CKSUMV5            (1U << 5)
 
 enum {
 	IFLA_RMNET_UNSPEC,
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH net-next v2 0/3] net: qualcomm: rmnet: Enable Mapv5

[subashab]

On 2021-02-22 09:55, Sharath Chandra Vurukala wrote:
> This series introduces the MAPv5 packet format.
> 
> Patch 0 documents the MAPv5.
> Patch 1 introduces the Mapv5 and the Inline checksum offload for RX.
> Patch 2 introduces the Mapv5 and the Inline checksum offload for TX.
> 
> A new checksum header format is used as part of MAPv5.
> For RX checksum offload, the checksum is verified by the HW and the
> validity is marked in the checksum header of MAPv5.
> for TX, the required metadata is filled up so hardware can compute the
> checksum.
> 
> v1->v2:
> - Fixed the compilation errors, warnings reported by kernel test robot.
> - Checksum header definition is expanded to support big, little endian
> formats as mentioned by Jakub.
> 
> Sharath Chandra Vurukala (3):
>   docs: networking: Add documentation for MAPv5
>   net: ethernet: rmnet: Support for downlink MAPv5 checksum offload
>   net: ethernet: rmnet: Add support for Mapv5 uplink packet
> 
>  .../device_drivers/cellular/qualcomm/rmnet.rst     |  53 ++++++-
>  drivers/net/ethernet/qualcomm/rmnet/rmnet_config.h |   4 +-
>  .../net/ethernet/qualcomm/rmnet/rmnet_handlers.c   |  34 +++--
>  drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h    |  22 ++-
>  .../net/ethernet/qualcomm/rmnet/rmnet_map_data.c   | 153
> ++++++++++++++++++++-
>  include/linux/if_rmnet.h                           |  24 +++-
>  include/uapi/linux/if_link.h                       |   2 +
>  7 files changed, 263 insertions(+), 29 deletions(-)

For the series-

Reviewed-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>

Re: [PATCH net-next v2 2/3] net: ethernet: rmnet: Support for downlink MAPv5 checksum offload

[Alex Elder]

On 2/22/21 10:55 AM, Sharath Chandra Vurukala wrote:
> Adding support for processing of Mapv5 downlink packets.
> It involves parsing the Mapv5 packet and checking the csum header
> to know whether the hardware has validated the checksum and is
> valid or not.
> 
> Based on the checksum valid bit the corresponding stats are
> incremented and skb->ip_summed is marked either CHECKSUM_UNNECESSARY
> or left as CHEKSUM_NONE to let network stack revalidated the checksum
> and update the respective snmp stats.
> 
> Current MapV1 header has been modified, the reserved field in the
> Mapv1 header is now used for next header indication.
> 
> Signed-off-by: Sharath Chandra Vurukala <sharathv@codeaurora.org>
> ---

. . .


> diff --git a/include/linux/if_rmnet.h b/include/linux/if_rmnet.h
> index 9661416..a6de521 100644
> --- a/include/linux/if_rmnet.h
> +++ b/include/linux/if_rmnet.h
> @@ -1,5 +1,5 @@
>   /* SPDX-License-Identifier: GPL-2.0-only
> - * Copyright (c) 2013-2019, The Linux Foundation. All rights reserved.
> + * Copyright (c) 2013-2019, 2021 The Linux Foundation. All rights reserved.
>    */
>   
>   #ifndef _LINUX_IF_RMNET_H_
> @@ -8,11 +8,11 @@
>   struct rmnet_map_header {
>   #if defined(__LITTLE_ENDIAN_BITFIELD)
>   	u8  pad_len:6;
> -	u8  reserved_bit:1;
> +	u8  next_hdr:1;
>   	u8  cd_bit:1;
>   #elif defined (__BIG_ENDIAN_BITFIELD)
>   	u8  cd_bit:1;
> -	u8  reserved_bit:1;
> +	u8  next_hdr:1;
>   	u8  pad_len:6;
>   #else
>   #error	"Please fix <asm/byteorder.h>"

. . .

I know that KS said he is "not convinced that it is
helping improve anything" and that it "just adds a
big overhead of testing everything again without
any improvement of performance or readability of
code."  But I will ask again that these structures
be redefined to use host byte-order masks and
structure fields with clearly defined endianness.

I strongly disagree with the statement from KS.
Specifically I feel the whole notion of "bit field
endianness" is not obvious, and makes it harder than
necessary to understand how the bits are laid out
in memory.  It also obscures in code that bit fields
have certain properties that are different from other
"normal" struct field types (such as alignment, size,
or atomicity of the field).  And I say this despite
knowing this pattern is used elsewhere in the
networking code.

In the first version of the series, Jakub asked that
the conversion be done.  I offered to implement the
change to the existing code, and that offer stands.
I can do so fairly quickly if you would like to have
it soon to build upon.

Either way, I would like a chance to review the
rest of this series, but I'd like to get this issue
resolved (either decide it must be done or not)
before I spend more time on that.

Thanks.

					-Alex

Re: [PATCH net-next v2 2/3] net: ethernet: rmnet: Support for downlink MAPv5 checksum offload

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 3347 bytes --]

Hi Sharath,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on net-next/master]

url:    https://github.com/0day-ci/linux/commits/Sharath-Chandra-Vurukala/net-qualcomm-rmnet-Enable-Mapv5/20210223-010109
base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git d310ec03a34e92a77302edb804f7d68ee4f01ba0
config: m68k-allmodconfig (attached as .config)
compiler: m68k-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/a96da20e1028049cc3824b52bb5293376c0868ce
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Sharath-Chandra-Vurukala/net-qualcomm-rmnet-Enable-Mapv5/20210223-010109
        git checkout a96da20e1028049cc3824b52bb5293376c0868ce
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=m68k 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   In file included from include/linux/kernel.h:10,
                    from include/linux/list.h:9,
                    from include/linux/timer.h:5,
                    from include/linux/netdevice.h:24,
                    from drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c:7:
   include/linux/scatterlist.h: In function 'sg_set_buf':
   arch/m68k/include/asm/page_mm.h:174:49: warning: ordered comparison of pointer with null pointer [-Wextra]
     174 | #define virt_addr_valid(kaddr) ((void *)(kaddr) >= (void *)PAGE_OFFSET && (void *)(kaddr) < high_memory)
         |                                                 ^~
   include/linux/compiler.h:78:42: note: in definition of macro 'unlikely'
      78 | # define unlikely(x) __builtin_expect(!!(x), 0)
         |                                          ^
   include/linux/scatterlist.h:137:2: note: in expansion of macro 'BUG_ON'
     137 |  BUG_ON(!virt_addr_valid(buf));
         |  ^~~~~~
   include/linux/scatterlist.h:137:10: note: in expansion of macro 'virt_addr_valid'
     137 |  BUG_ON(!virt_addr_valid(buf));
         |          ^~~~~~~~~~~~~~~
   In file included from drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h:7,
                    from drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c:14:
   include/linux/if_rmnet.h: At top level:
>> include/linux/if_rmnet.h:66:2: error: expected ',', ';' or '}' before 'u8'
      66 |  u8  hw_reserved:7;
         |  ^~


vim +66 include/linux/if_rmnet.h

    54	
    55	/* MAP CSUM headers */
    56	struct rmnet_map_v5_csum_header {
    57	#if defined(__LITTLE_ENDIAN_BITFIELD)
    58		u8  next_hdr:1;
    59		u8  header_type:7;
    60		u8  hw_reserved:7;
    61		u8  csum_valid_required:1;
    62	#elif defined(__BIG_ENDIAN_BITFIELD)
    63		u8  header_type:7;
    64		u8  next_hdr:1;
    65		u8  csum_valid_required:1
  > 66		u8  hw_reserved:7;
    67	#else
    68	#error	"Please fix <asm/byteorder.h>"
    69	#endif
    70		__be16 reserved;
    71	} __aligned(1);
    72	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 59709 bytes --]

Re: [PATCH net-next v2 2/3] net: ethernet: rmnet: Support for downlink MAPv5 checksum offload

[Geert Uytterhoeven]

Hi Kernel Test Robot,

On Mon, Feb 22, 2021 at 10:02 PM kernel test robot <lkp@intel.com> wrote:
> Thank you for the patch! Yet something to improve:
>
> [auto build test ERROR on net-next/master]
>
> url:    https://github.com/0day-ci/linux/commits/Sharath-Chandra-Vurukala/net-qualcomm-rmnet-Enable-Mapv5/20210223-010109
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git d310ec03a34e92a77302edb804f7d68ee4f01ba0
> config: m68k-allmodconfig (attached as .config)
> compiler: m68k-linux-gcc (GCC) 9.3.0
> reproduce (this is a W=1 build):
>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # https://github.com/0day-ci/linux/commit/a96da20e1028049cc3824b52bb5293376c0868ce
>         git remote add linux-review https://github.com/0day-ci/linux
>         git fetch --no-tags linux-review Sharath-Chandra-Vurukala/net-qualcomm-rmnet-Enable-Mapv5/20210223-010109
>         git checkout a96da20e1028049cc3824b52bb5293376c0868ce
>         # save the attached .config to linux build tree
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=m68k
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
>
> All errors (new ones prefixed by >>):
>
>    In file included from include/linux/kernel.h:10,
>                     from include/linux/list.h:9,
>                     from include/linux/timer.h:5,
>                     from include/linux/netdevice.h:24,
>                     from drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c:7:
>    include/linux/scatterlist.h: In function 'sg_set_buf':
>    arch/m68k/include/asm/page_mm.h:174:49: warning: ordered comparison of pointer with null pointer [-Wextra]
>      174 | #define virt_addr_valid(kaddr) ((void *)(kaddr) >= (void *)PAGE_OFFSET && (void *)(kaddr) < high_memory)
>          |                                                 ^~
>    include/linux/compiler.h:78:42: note: in definition of macro 'unlikely'
>       78 | # define unlikely(x) __builtin_expect(!!(x), 0)
>          |                                          ^
>    include/linux/scatterlist.h:137:2: note: in expansion of macro 'BUG_ON'
>      137 |  BUG_ON(!virt_addr_valid(buf));
>          |  ^~~~~~
>    include/linux/scatterlist.h:137:10: note: in expansion of macro 'virt_addr_valid'
>      137 |  BUG_ON(!virt_addr_valid(buf));
>          |          ^~~~~~~~~~~~~~~

Note that the warning is unrelated. I've sent a patch to quiten it.
[PATCH] m68k: Fix virt_addr_valid() W=1 compiler warnings
https://lore.kernel.org/linux-m68k/20210223104957.2209219-1-geert@linux-m68k.org/

>    In file included from drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h:7,
>                     from drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c:14:
>    include/linux/if_rmnet.h: At top level:
> >> include/linux/if_rmnet.h:66:2: error: expected ',', ';' or '}' before 'u8'
>       66 |  u8  hw_reserved:7;
>          |  ^~

That's a real one, though.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds