[RFC PATCH 1/6] cdc_ncm: factor out skb allocation and finalizzing
From: Enrico Mioso <hidden>
Date: 2014-12-29 10:09:51
Subsystem:
networking drivers, the rest, usb cdc ethernet driver, usb networking drivers · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Oliver Neukum
This might help when we will refactor the code to prepare frames only when we have enough data, allowing us to re-order the position of different NCM fields. Signed-Off-By: Enrico Mioso <redacted> --- drivers/net/usb/cdc_ncm.c | 46 +++++++++++++++++++++++++++++++++++----------- 1 file changed, 35 insertions(+), 11 deletions(-)
diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index 389a3a4..48fee7a 100644
--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c@@ -1014,6 +1014,36 @@ static struct usb_cdc_ncm_ndp16 *cdc_ncm_ndp16(struct cdc_ncm_ctx *ctx, struct s return ndp16; } +/* Allocate new SKB for use with 16-bit NCM according to actual TX/RX + settings */ +struct sk_buff * +cdc_ncm_prepare_skb_ncm16(struct sk_buff *skb, struct cdc_ncm_ctx *ctx) +{ + struct usb_cdc_ncm_nth16 *nth16; + + skb = alloc_skb(ctx->tx_max, GFP_ATOMIC); + if (skb == NULL) + goto exit_no_mem; + + /* fill out the initial 16-bit NTB header */ + nth16 = (struct usb_cdc_ncm_nth16 *)memset(skb_put(skb, sizeof(struct usb_cdc_ncm_nth16)), 0, sizeof(struct usb_cdc_ncm_nth16)); + nth16->dwSignature = cpu_to_le32(USB_CDC_NCM_NTH16_SIGN); + nth16->wHeaderLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_nth16)); + nth16->wSequence = cpu_to_le16(ctx->tx_seq++); + +exit_no_mem: + return skb; +} + +/* Adjust 16-bit NCM header frame length */ +struct usb_cdc_ncm_nth16 * +cdc_ncm_finalize_nth16(struct usb_cdc_ncm_nth16 *nth16, struct sk_buff *skb) +{ + nth16 = (struct usb_cdc_ncm_nth16 *)skb->data; + nth16->wBlockLength = cpu_to_le16(skb->len); + return nth16; +} + struct sk_buff * cdc_ncm_fill_tx_frame(struct usbnet *dev, struct sk_buff *skb, __le32 sign) {
@@ -1037,7 +1067,7 @@ cdc_ncm_fill_tx_frame(struct usbnet *dev, struct sk_buff *skb, __le32 sign) /* allocate a new OUT skb */ if (!skb_out) { - skb_out = alloc_skb(ctx->tx_max, GFP_ATOMIC); + skb_out = cdc_ncm_prepare_skb_ncm16(skb_out, ctx); if (skb_out == NULL) { if (skb != NULL) { dev_kfree_skb_any(skb);
@@ -1045,11 +1075,6 @@ cdc_ncm_fill_tx_frame(struct usbnet *dev, struct sk_buff *skb, __le32 sign) } goto exit_no_skb; } - /* fill out the initial 16-bit NTB header */ - nth16 = (struct usb_cdc_ncm_nth16 *)memset(skb_put(skb_out, sizeof(struct usb_cdc_ncm_nth16)), 0, sizeof(struct usb_cdc_ncm_nth16)); - nth16->dwSignature = cpu_to_le32(USB_CDC_NCM_NTH16_SIGN); - nth16->wHeaderLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_nth16)); - nth16->wSequence = cpu_to_le16(ctx->tx_seq++); /* count total number of frames in this NTB */ ctx->tx_curr_frame_num = 0;
@@ -1165,11 +1190,10 @@ cdc_ncm_fill_tx_frame(struct usbnet *dev, struct sk_buff *skb, __le32 sign) ctx->tx_max - skb_out->len); else if (skb_out->len < ctx->tx_max && (skb_out->len % dev->maxpacket) == 0) *skb_put(skb_out, 1) = 0; /* force short packet */ - - /* set final frame length */ - nth16 = (struct usb_cdc_ncm_nth16 *)skb_out->data; - nth16->wBlockLength = cpu_to_le16(skb_out->len); - + + /* Finalize packet */ + nth16 = cdc_ncm_finalize_nth16(nth16, skb_out); + /* return skb */ ctx->tx_curr_skb = NULL; dev->net->stats.tx_packets += ctx->tx_curr_frame_num;
--
2.2.1