Messages in this thread | | | Date | Thu, 28 May 2020 07:34:40 -0700 | From | Richard Cochran <> | Subject | Re: [PATCH net-next 6/8] net: phy: mscc: timestamping and PHC support |
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On Wed, May 27, 2020 at 06:41:56PM +0200, Antoine Tenart wrote:
> +static struct vsc85xx_ptphdr *get_ptp_header(struct sk_buff *skb) > +{ > + struct ethhdr *ethhdr = eth_hdr(skb); > + struct iphdr *iphdr = ip_hdr(skb); > + struct udphdr *udphdr; > + __u8 proto; > + > + if (ethhdr->h_proto == htons(ETH_P_1588)) > + return (struct vsc85xx_ptphdr *)(((unsigned char *)ethhdr) + > + skb_mac_header_len(skb)); > + > + if (ethhdr->h_proto != htons(ETH_P_IP)) > + return NULL; > + > + proto = iphdr->protocol; > + if (proto != IPPROTO_UDP) > + return NULL; > + > + udphdr = udp_hdr(skb); > + > + if (udphdr->source != ntohs(PTP_EV_PORT) || > + udphdr->dest != ntohs(PTP_EV_PORT)) > + return NULL; > + > + return (struct vsc85xx_ptphdr *)(((unsigned char *)udphdr) + UDP_HLEN); > +}
This looks a lot like get_ptp_header_rx() below. Are you sure you need two almost identical methods?
> +static void vsc85xx_get_tx_ts(struct vsc85xx_ptp *ptp) > +{ > + struct skb_shared_hwtstamps shhwtstamps; > + struct sk_buff *skb, *first_skb = NULL; > + struct vsc85xx_ts_fifo fifo; > + u8 i, skb_sig[16], *p; > + unsigned long ns; > + s64 secs; > + u32 reg; > + > +next_in_fifo: > + memset(&fifo, 0, sizeof(fifo)); > + p = (u8 *)&fifo; > + > + reg = vsc85xx_ts_read_csr(ptp->phydev, PROCESSOR, > + MSCC_PHY_PTP_EGR_TS_FIFO(0)); > + if (reg & PTP_EGR_TS_FIFO_EMPTY) > + goto out; > + > + *p++ = reg & 0xff; > + *p++ = (reg >> 8) & 0xff; > + > + /* Reading FIFO6 pops the FIFO item */ > + for (i = 1; i < 7; i++) { > + reg = vsc85xx_ts_read_csr(ptp->phydev, PROCESSOR, > + MSCC_PHY_PTP_EGR_TS_FIFO(i)); > + *p++ = reg & 0xff; > + *p++ = (reg >> 8) & 0xff; > + *p++ = (reg >> 16) & 0xff; > + *p++ = (reg >> 24) & 0xff; > + } > + > +next_in_queue: > + skb = skb_dequeue(&ptp->tx_queue); > + if (!skb || skb == first_skb) > + goto out; > + > + /* Keep the first skb to avoid looping over it again. */ > + if (!first_skb) > + first_skb = skb; > + > + /* Can't get the signature of the packet, won't ever > + * be able to have one so let's dequeue the packet. > + */ > + if (get_sig(skb, skb_sig) < 0) > + goto next_in_queue; > + > + /* Valid signature but does not match the one of the > + * packet in the FIFO right now, reschedule it for later > + * packets. > + */ > + if (memcmp(skb_sig, fifo.sig, sizeof(fifo.sig))) { > + skb_queue_tail(&ptp->tx_queue, skb); > + goto next_in_queue; > + } > + > + ns = fifo.ns; > + secs = fifo.secs; > + > + memset(&shhwtstamps, 0, sizeof(shhwtstamps)); > + shhwtstamps.hwtstamp = ktime_set(secs, ns); > + skb_complete_tx_timestamp(skb, &shhwtstamps); > + > +out: > + /* If other timestamps are available in the FIFO, process them. */ > + reg = vsc85xx_ts_read_csr(ptp->phydev, PROCESSOR, > + MSCC_PHY_PTP_EGR_TS_FIFO_CTRL); > + if (PTP_EGR_FIFO_LEVEL_LAST_READ(reg) > 1) > + goto next_in_fifo; > +}
AFAICT, there is no need for labels and jumps here. Two nested 'for' loops will do nicely. The inner skb loop can be in a helper function for clarity. Be sure to use the "safe" iterator over the skbs.
> +static void vsc85xx_txtstamp(struct mii_timestamper *mii_ts, > + struct sk_buff *skb, int type) > +{ > + struct vsc8531_private *vsc8531 = > + container_of(mii_ts, struct vsc8531_private, mii_ts); > + > + if (!skb || !vsc8531->ptp->configured)
The skb cannot be NULL here. See net/core/timestamping.c
> + return; > + > + if (vsc8531->ptp->tx_type == HWTSTAMP_TX_OFF) { > + kfree_skb(skb); > + return; > + } > + > + skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS; > + skb_queue_tail(&vsc8531->ptp->tx_queue, skb); > + /* Scheduling the work for the TS FIFO is handled by the IRQ routine */ > +} > + > +static bool vsc85xx_rxtstamp(struct mii_timestamper *mii_ts, > + struct sk_buff *skb, int type) > +{ > + struct vsc8531_private *vsc8531 = > + container_of(mii_ts, struct vsc8531_private, mii_ts); > + struct skb_shared_hwtstamps *shhwtstamps = NULL; > + struct vsc85xx_ptphdr *ptphdr; > + struct timespec64 ts; > + unsigned long ns; > + > + if (!skb || !vsc8531->ptp->configured)
Again, skb can't be null.
Thanks, Richard
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