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From:   Alex Elder <elder@linaro.org>
To:     subashab@codeaurora.org, stranche@codeaurora.org,
        davem@davemloft.net, kuba@kernel.org
Cc:     sharathv@codeaurora.org, bjorn.andersson@linaro.org,
        evgreen@chromium.org, cpratapa@codeaurora.org, elder@kernel.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH net-next 3/6] net: qualcomm: rmnet: kill RMNET_MAP_GET_*() accessor macros
Date:   Thu,  4 Mar 2021 16:34:28 -0600
Message-Id: <20210304223431.15045-4-elder@linaro.org>
In-Reply-To: <20210304223431.15045-1-elder@linaro.org>
References: <20210304223431.15045-1-elder@linaro.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

The following macros, defined in "rmnet_map.h", assume a socket
buffer is provided as an argument without any real indication this
is the case.
    RMNET_MAP_GET_MUX_ID()
    RMNET_MAP_GET_CD_BIT()
    RMNET_MAP_GET_PAD()
    RMNET_MAP_GET_CMD_START()
    RMNET_MAP_GET_LENGTH()
What they hide is pretty trivial accessing of fields in a structure,
and it's much clearer to see this if we do these accesses directly.

So rather than using these accessor macros, assign a local
variable of the map header pointer type to the socket buffer data
pointer, and derereference that pointer variable.

In "rmnet_map_data.c", use sizeof(object) rather than sizeof(type)
in one spot.  Also,there's no need to byte swap 0; it's all zeros
irrespective of endianness.

Signed-off-by: Alex Elder <elder@linaro.org>
---
 drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c | 10 ++++++----
 drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h      | 12 ------------
 .../net/ethernet/qualcomm/rmnet/rmnet_map_command.c  | 11 ++++++++---
 drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c |  4 ++--
 4 files changed, 16 insertions(+), 21 deletions(-)

diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c
index 3d00b32323084..2a6b2a609884c 100644
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c
@@ -56,20 +56,22 @@ static void
 __rmnet_map_ingress_handler(struct sk_buff *skb,
 			    struct rmnet_port *port)
 {
+	struct rmnet_map_header *map_header = (void *)skb->data;
 	struct rmnet_endpoint *ep;
 	u16 len, pad;
 	u8 mux_id;
 
-	if (RMNET_MAP_GET_CD_BIT(skb)) {
+	if (map_header->cd_bit) {
+		/* Packet contains a MAP command (not data) */
 		if (port->data_format & RMNET_FLAGS_INGRESS_MAP_COMMANDS)
 			return rmnet_map_command(skb, port);
 
 		goto free_skb;
 	}
 
-	mux_id = RMNET_MAP_GET_MUX_ID(skb);
-	pad = RMNET_MAP_GET_PAD(skb);
-	len = RMNET_MAP_GET_LENGTH(skb) - pad;
+	mux_id = map_header->mux_id;
+	pad = map_header->pad_len;
+	len = ntohs(map_header->pkt_len) - pad;
 
 	if (mux_id >= RMNET_MAX_LOGICAL_EP)
 		goto free_skb;
diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h
index 576501db2a0bc..2aea153f42473 100644
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h
@@ -32,18 +32,6 @@ enum rmnet_map_commands {
 	RMNET_MAP_COMMAND_ENUM_LENGTH
 };
 
-#define RMNET_MAP_GET_MUX_ID(Y) (((struct rmnet_map_header *) \
-				 (Y)->data)->mux_id)
-#define RMNET_MAP_GET_CD_BIT(Y) (((struct rmnet_map_header *) \
-				(Y)->data)->cd_bit)
-#define RMNET_MAP_GET_PAD(Y) (((struct rmnet_map_header *) \
-				(Y)->data)->pad_len)
-#define RMNET_MAP_GET_CMD_START(Y) ((struct rmnet_map_control_command *) \
-				    ((Y)->data + \
-				      sizeof(struct rmnet_map_header)))
-#define RMNET_MAP_GET_LENGTH(Y) (ntohs(((struct rmnet_map_header *) \
-					(Y)->data)->pkt_len))
-
 #define RMNET_MAP_COMMAND_REQUEST     0
 #define RMNET_MAP_COMMAND_ACK         1
 #define RMNET_MAP_COMMAND_UNSUPPORTED 2
diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_command.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_command.c
index beaee49621287..add0f5ade2e61 100644
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_command.c
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_command.c
@@ -12,12 +12,13 @@ static u8 rmnet_map_do_flow_control(struct sk_buff *skb,
 				    struct rmnet_port *port,
 				    int enable)
 {
+	struct rmnet_map_header *map_header = (void *)skb->data;
 	struct rmnet_endpoint *ep;
 	struct net_device *vnd;
 	u8 mux_id;
 	int r;
 
-	mux_id = RMNET_MAP_GET_MUX_ID(skb);
+	mux_id = map_header->mux_id;
 
 	if (mux_id >= RMNET_MAX_LOGICAL_EP) {
 		kfree_skb(skb);
@@ -49,6 +50,7 @@ static void rmnet_map_send_ack(struct sk_buff *skb,
 			       unsigned char type,
 			       struct rmnet_port *port)
 {
+	struct rmnet_map_header *map_header = (void *)skb->data;
 	struct rmnet_map_control_command *cmd;
 	struct net_device *dev = skb->dev;
 
@@ -58,7 +60,8 @@ static void rmnet_map_send_ack(struct sk_buff *skb,
 
 	skb->protocol = htons(ETH_P_MAP);
 
-	cmd = RMNET_MAP_GET_CMD_START(skb);
+	/* Command data immediately follows the MAP header */
+	cmd = (struct rmnet_map_control_command *)(map_header + 1);
 	cmd->cmd_type = type & 0x03;
 
 	netif_tx_lock(dev);
@@ -71,11 +74,13 @@ static void rmnet_map_send_ack(struct sk_buff *skb,
  */
 void rmnet_map_command(struct sk_buff *skb, struct rmnet_port *port)
 {
+	struct rmnet_map_header *map_header = (void *)skb->data;
 	struct rmnet_map_control_command *cmd;
 	unsigned char command_name;
 	unsigned char rc = 0;
 
-	cmd = RMNET_MAP_GET_CMD_START(skb);
+	/* Command data immediately follows the MAP header */
+	cmd = (struct rmnet_map_control_command *)(map_header + 1);
 	command_name = cmd->command_name;
 
 	switch (command_name) {
diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c
index bd1aa11c9ce59..fd55269c2ce3c 100644
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c
@@ -321,7 +321,7 @@ struct sk_buff *rmnet_map_deaggregate(struct sk_buff *skb,
 		return NULL;
 
 	maph = (struct rmnet_map_header *)skb->data;
-	packet_len = ntohs(maph->pkt_len) + sizeof(struct rmnet_map_header);
+	packet_len = ntohs(maph->pkt_len) + sizeof(*maph);
 
 	if (port->data_format & RMNET_FLAGS_INGRESS_MAP_CKSUMV4)
 		packet_len += sizeof(struct rmnet_map_dl_csum_trailer);
@@ -330,7 +330,7 @@ struct sk_buff *rmnet_map_deaggregate(struct sk_buff *skb,
 		return NULL;
 
 	/* Some hardware can send us empty frames. Catch them */
-	if (ntohs(maph->pkt_len) == 0)
+	if (!maph->pkt_len)
 		return NULL;
 
 	skbn = alloc_skb(packet_len + RMNET_MAP_DEAGGR_SPACING, GFP_ATOMIC);
-- 
2.20.1