[3/8] net: qualcomm: rmnet: use field masks instead of C bit-fields

Message ID 20190520135354.18628-4-elder@linaro.org
State New
Headers show
Series
  • net: introduce "include/linux/if_rmnet.h"
Related show

Commit Message

Alex Elder May 20, 2019, 1:53 p.m.
Using C bitfields (e.g. int foo : 3) is not portable.  So stop
using them for the command/data flag and the pad length fields in
the rmnet_map structure.  Instead, use the functions defined in
<linux/bitfield.h> along with field mask constants to extract or
assign values within an integral structure member of a known size.

Signed-off-by: Alex Elder <elder@linaro.org>

---
 drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c | 5 +++--
 drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h      | 8 +++++---
 drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c | 5 ++++-
 3 files changed, 12 insertions(+), 6 deletions(-)

-- 
2.20.1

Comments

Bjorn Andersson May 20, 2019, 3:43 p.m. | #1
On Mon 20 May 06:53 PDT 2019, Alex Elder wrote:

> Using C bitfields (e.g. int foo : 3) is not portable.  So stop

> using them for the command/data flag and the pad length fields in

> the rmnet_map structure.  Instead, use the functions defined in

> <linux/bitfield.h> along with field mask constants to extract or

> assign values within an integral structure member of a known size.

> 


Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>


> Signed-off-by: Alex Elder <elder@linaro.org>

> ---

>  drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c | 5 +++--

>  drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h      | 8 +++++---

>  drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c | 5 ++++-

>  3 files changed, 12 insertions(+), 6 deletions(-)

> 

> diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c

> index 4c1b62b72504..5fff6c78ecd5 100644

> --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c

> +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c

> @@ -13,6 +13,7 @@

>   *

>   */

>  

> +#include <linux/bitfield.h>

>  #include <linux/netdevice.h>

>  #include <linux/netdev_features.h>

>  #include <linux/if_arp.h>

> @@ -70,7 +71,7 @@ __rmnet_map_ingress_handler(struct sk_buff *skb,

>  	u16 len, pad;

>  	u8 mux_id;

>  

> -	if (map_header->cd_bit) {

> +	if (u8_get_bits(map_header->cmd_pad_len, RMNET_MAP_CMD_FMASK)) {

>  		if (port->data_format & RMNET_FLAGS_INGRESS_MAP_COMMANDS)

>  			return rmnet_map_command(skb, port);

>  

> @@ -78,7 +79,7 @@ __rmnet_map_ingress_handler(struct sk_buff *skb,

>  	}

>  

>  	mux_id = map_header->mux_id;

> -	pad = map_header->pad_len;

> +	pad = u8_get_bits(map_header->cmd_pad_len, RMNET_MAP_PAD_LEN_FMASK);

>  	len = ntohs(map_header->pkt_len) - pad;

>  

>  	if (mux_id >= RMNET_MAX_LOGICAL_EP)

> diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h

> index a30a7b405a11..a56209645c81 100644

> --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h

> +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h

> @@ -40,13 +40,15 @@ enum rmnet_map_commands {

>  };

>  

>  struct rmnet_map_header {

> -	u8  cd_bit:1;

> -	u8  reserved_bit:1;

> -	u8  pad_len:6;

> +	u8  cmd_pad_len;	/* RMNET_MAP_* */

>  	u8  mux_id;

>  	__be16 pkt_len;

>  }  __aligned(1);

>  

> +#define RMNET_MAP_CMD_FMASK		GENMASK(0, 0)   /* 0: data; 1: cmd */

> +#define RMNET_MAP_RESERVED_FMASK	GENMASK(1, 1)

> +#define RMNET_MAP_PAD_LEN_FMASK		GENMASK(7, 2)

> +

>  struct rmnet_map_dl_csum_trailer {

>  	u8  reserved1;

>  	u8  valid:1;

> diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c

> index 498f20ba1826..10d2d582a9ce 100644

> --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c

> +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c

> @@ -13,6 +13,7 @@

>   *

>   */

>  

> +#include <linux/bitfield.h>

>  #include <linux/netdevice.h>

>  #include <linux/ip.h>

>  #include <linux/ipv6.h>

> @@ -301,7 +302,9 @@ struct rmnet_map_header *rmnet_map_add_map_header(struct sk_buff *skb,

>  

>  done:

>  	map_header->pkt_len = htons(map_datalen + padding);

> -	map_header->pad_len = padding & 0x3F;

> +	/* This is a data packet, so cmd field is 0 */

> +	map_header->cmd_pad_len =

> +			u8_encode_bits(padding, RMNET_MAP_PAD_LEN_FMASK);

>  

>  	return map_header;

>  }

> -- 

> 2.20.1

>

Patch

diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c
index 4c1b62b72504..5fff6c78ecd5 100644
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c
@@ -13,6 +13,7 @@ 
  *
  */
 
+#include <linux/bitfield.h>
 #include <linux/netdevice.h>
 #include <linux/netdev_features.h>
 #include <linux/if_arp.h>
@@ -70,7 +71,7 @@  __rmnet_map_ingress_handler(struct sk_buff *skb,
 	u16 len, pad;
 	u8 mux_id;
 
-	if (map_header->cd_bit) {
+	if (u8_get_bits(map_header->cmd_pad_len, RMNET_MAP_CMD_FMASK)) {
 		if (port->data_format & RMNET_FLAGS_INGRESS_MAP_COMMANDS)
 			return rmnet_map_command(skb, port);
 
@@ -78,7 +79,7 @@  __rmnet_map_ingress_handler(struct sk_buff *skb,
 	}
 
 	mux_id = map_header->mux_id;
-	pad = map_header->pad_len;
+	pad = u8_get_bits(map_header->cmd_pad_len, RMNET_MAP_PAD_LEN_FMASK);
 	len = ntohs(map_header->pkt_len) - pad;
 
 	if (mux_id >= RMNET_MAX_LOGICAL_EP)
diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h
index a30a7b405a11..a56209645c81 100644
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h
@@ -40,13 +40,15 @@  enum rmnet_map_commands {
 };
 
 struct rmnet_map_header {
-	u8  cd_bit:1;
-	u8  reserved_bit:1;
-	u8  pad_len:6;
+	u8  cmd_pad_len;	/* RMNET_MAP_* */
 	u8  mux_id;
 	__be16 pkt_len;
 }  __aligned(1);
 
+#define RMNET_MAP_CMD_FMASK		GENMASK(0, 0)   /* 0: data; 1: cmd */
+#define RMNET_MAP_RESERVED_FMASK	GENMASK(1, 1)
+#define RMNET_MAP_PAD_LEN_FMASK		GENMASK(7, 2)
+
 struct rmnet_map_dl_csum_trailer {
 	u8  reserved1;
 	u8  valid:1;
diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c
index 498f20ba1826..10d2d582a9ce 100644
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c
@@ -13,6 +13,7 @@ 
  *
  */
 
+#include <linux/bitfield.h>
 #include <linux/netdevice.h>
 #include <linux/ip.h>
 #include <linux/ipv6.h>
@@ -301,7 +302,9 @@  struct rmnet_map_header *rmnet_map_add_map_header(struct sk_buff *skb,
 
 done:
 	map_header->pkt_len = htons(map_datalen + padding);
-	map_header->pad_len = padding & 0x3F;
+	/* This is a data packet, so cmd field is 0 */
+	map_header->cmd_pad_len =
+			u8_encode_bits(padding, RMNET_MAP_PAD_LEN_FMASK);
 
 	return map_header;
 }