Messages in this thread | | | Subject | Re: [PATCH net-next 6/8] net: phy: mscc: timestamping and PHC support | From | Antoine Tenart <> | Date | Thu, 28 May 2020 17:23:52 +0200 |
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Hello Richard,
Quoting Richard Cochran (2020-05-28 16:34:40) > 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?
That's right, good catch. I'll look into merging the two.
> > +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.
Using helper functions for clarity, I could move to using loops. I'll try that and if it improves readability I'll change this for v2.
> > +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.
Right, I'll fix the two.
Thanks for the review! Antoine
-- Antoine Ténart, Bootlin Embedded Linux and Kernel engineering https://bootlin.com
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