| Message ID | 20211012123557.3547280-5-alvin@pqrs.dk (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | net: dsa: add support for RTL8365MB-VC | expand |
On Tue, Oct 12, 2021 at 02:35:53PM +0200, Alvin Šipraga wrote: > From: Alvin Šipraga <alsi@bang-olufsen.dk> > > This commit implements a basic version of the 8 byte tag protocol used > in the Realtek RTL8365MB-VC unmanaged switch, which carries with it a > protocol version of 0x04. > > The implementation itself only handles the parsing of the EtherType > value and Realtek protocol version, together with the source or > destination port fields. The rest is left unimplemented for now. > > The tag format is described in a confidential document provided to my > company by Realtek Semiconductor Corp. Permission has been granted by > the vendor to publish this driver based on that material, together with > an extract from the document describing the tag format and its fields. > It is hoped that this will help future implementors who do not have > access to the material but who wish to extend the functionality of > drivers for chips which use this protocol. > > In addition, two possible values of the REASON field are specified, > based on experiments on my end. Realtek does not specify what value this > field can take. > > Signed-off-by: Alvin Šipraga <alsi@bang-olufsen.dk> > --- Reviewed-by: Vladimir Oltean <olteanv@gmail.com> > RFC -> v1: > - minor changes to the big comment at the top, including some > empirical information about the REASON code > - use dev_*_ratelimited() instead of netdev_*() for logging > - use warning instead of debug messages > - use ETH_P_REALTEK from if_ether.h > - set LEARN_DIS on xmit > - remove superfluous variables/expressions and use __b16 for tag > variable > - use new helper functions to insert/remove CPU tag > - set offload_fwd_mark properly using helper function > > include/net/dsa.h | 2 + > net/dsa/Kconfig | 6 ++ > net/dsa/Makefile | 1 + > net/dsa/tag_rtl8_4.c | 166 +++++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 175 insertions(+) > create mode 100644 net/dsa/tag_rtl8_4.c > > diff --git a/include/net/dsa.h b/include/net/dsa.h > index d784e76113b8..783060e851a9 100644 > --- a/include/net/dsa.h > +++ b/include/net/dsa.h > @@ -51,6 +51,7 @@ struct phylink_link_state; > #define DSA_TAG_PROTO_SEVILLE_VALUE 21 > #define DSA_TAG_PROTO_BRCM_LEGACY_VALUE 22 > #define DSA_TAG_PROTO_SJA1110_VALUE 23 > +#define DSA_TAG_PROTO_RTL8_4_VALUE 24 > > enum dsa_tag_protocol { > DSA_TAG_PROTO_NONE = DSA_TAG_PROTO_NONE_VALUE, > @@ -77,6 +78,7 @@ enum dsa_tag_protocol { > DSA_TAG_PROTO_OCELOT_8021Q = DSA_TAG_PROTO_OCELOT_8021Q_VALUE, > DSA_TAG_PROTO_SEVILLE = DSA_TAG_PROTO_SEVILLE_VALUE, > DSA_TAG_PROTO_SJA1110 = DSA_TAG_PROTO_SJA1110_VALUE, > + DSA_TAG_PROTO_RTL8_4 = DSA_TAG_PROTO_RTL8_4_VALUE, > }; > > struct dsa_switch; > diff --git a/net/dsa/Kconfig b/net/dsa/Kconfig > index 6c7f79e45886..57fc52b17d55 100644 > --- a/net/dsa/Kconfig > +++ b/net/dsa/Kconfig > @@ -130,6 +130,12 @@ config NET_DSA_TAG_RTL4_A > Realtek switches with 4 byte protocol A tags, sich as found in > the Realtek RTL8366RB. > > +config NET_DSA_TAG_RTL8_4 > + tristate "Tag driver for Realtek 8 byte protocol 4 tags" > + help > + Say Y or M if you want to enable support for tagging frames for Realtek > + switches with 8 byte protocol 4 tags, such as the Realtek RTL8365MB-VC. > + > config NET_DSA_TAG_LAN9303 > tristate "Tag driver for SMSC/Microchip LAN9303 family of switches" > help > diff --git a/net/dsa/Makefile b/net/dsa/Makefile > index f78d537044db..9f75820e7c98 100644 > --- a/net/dsa/Makefile > +++ b/net/dsa/Makefile > @@ -16,6 +16,7 @@ obj-$(CONFIG_NET_DSA_TAG_OCELOT) += tag_ocelot.o > obj-$(CONFIG_NET_DSA_TAG_OCELOT_8021Q) += tag_ocelot_8021q.o > obj-$(CONFIG_NET_DSA_TAG_QCA) += tag_qca.o > obj-$(CONFIG_NET_DSA_TAG_RTL4_A) += tag_rtl4_a.o > +obj-$(CONFIG_NET_DSA_TAG_RTL8_4) += tag_rtl8_4.o > obj-$(CONFIG_NET_DSA_TAG_SJA1105) += tag_sja1105.o > obj-$(CONFIG_NET_DSA_TAG_TRAILER) += tag_trailer.o > obj-$(CONFIG_NET_DSA_TAG_XRS700X) += tag_xrs700x.o > diff --git a/net/dsa/tag_rtl8_4.c b/net/dsa/tag_rtl8_4.c > new file mode 100644 > index 000000000000..da22fd12b645 > --- /dev/null > +++ b/net/dsa/tag_rtl8_4.c > @@ -0,0 +1,166 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Handler for Realtek 8 byte switch tags > + * > + * Copyright (C) 2021 Alvin Šipraga <alsi@bang-olufsen.dk> > + * > + * NOTE: Currently only supports protocol "4" found in the RTL8365MB, hence > + * named tag_rtl8_4. > + * > + * This tag header has the following format: > + * > + * ------------------------------------------- > + * | MAC DA | MAC SA | 8 byte tag | Type | ... > + * ------------------------------------------- > + * _______________/ \______________________________________ > + * / \ > + * 0 7|8 15 > + * |-----------------------------------+-----------------------------------|--- > + * | (16-bit) | ^ > + * | Realtek EtherType [0x8899] | | > + * |-----------------------------------+-----------------------------------| 8 > + * | (8-bit) | (8-bit) | > + * | Protocol [0x04] | REASON | b > + * |-----------------------------------+-----------------------------------| y > + * | (1) | (1) | (2) | (1) | (3) | (1) | (1) | (1) | (5) | t > + * | FID_EN | X | FID | PRI_EN | PRI | KEEP | X | LEARN_DIS | X | e > + * |-----------------------------------+-----------------------------------| s After our previous discussion I thought you said these bits were an EFID_EN and EFID? Or did you reconsider? > + * | (1) | (15-bit) | | > + * | ALLOW | TX/RX | v > + * |-----------------------------------+-----------------------------------|--- > + * > + * With the following field descriptions: > + * > + * field | description > + * ------------+------------- > + * Realtek | 0x8899: indicates that this is a proprietary Realtek tag; > + * EtherType | note that Realtek uses the same EtherType for > + * | other incompatible tag formats (e.g. tag_rtl4_a.c) > + * Protocol | 0x04: indicates that this tag conforms to this format > + * X | reserved > + * ------------+------------- > + * REASON | reason for forwarding packet to CPU > + * | 0: packet was forwarded or flooded to CPU > + * | 80: packet was trapped to CPU > + * FID_EN | 1: packet has an FID > + * | 0: no FID > + * FID | FID of packet (if FID_EN=1) > + * PRI_EN | 1: force priority of packet > + * | 0: don't force priority > + * PRI | priority of packet (if PRI_EN=1) > + * KEEP | preserve packet VLAN tag format > + * LEARN_DIS | don't learn the source MAC address of the packet > + * ALLOW | 1: treat TX/RX field as an allowance port mask, meaning the > + * | packet may only be forwarded to ports specified in the > + * | mask > + * | 0: no allowance port mask, TX/RX field is the forwarding > + * | port mask > + * TX/RX | TX (switch->CPU): port number the packet was received on > + * | RX (CPU->switch): forwarding port mask (if ALLOW=0) > + * | allowance port mask (if ALLOW=1) > + */ > + > +#include <linux/bits.h> > +#include <linux/etherdevice.h> > + > +#include "dsa_priv.h" > + > +#define RTL8_4_TAG_LEN 8 > +/* 0x04 = RTL8365MB DSA protocol > + */ > +#define RTL8_4_PROTOCOL_RTL8365MB 0x04 > + > +static struct sk_buff *rtl8_4_tag_xmit(struct sk_buff *skb, > + struct net_device *dev) > +{ > + struct dsa_port *dp = dsa_slave_to_port(dev); > + __be16 *tag; > + > + /* Pad out so the (stripped) packet is at least 64 bytes long > + * (including FCS), otherwise the switch will drop the packet. > + * Then we need an additional 8 bytes for the Realtek tag. > + */ > + if (unlikely(__skb_put_padto(skb, ETH_ZLEN + RTL8_4_TAG_LEN, false))) > + return NULL; > + > + skb_push(skb, RTL8_4_TAG_LEN); > + > + dsa_alloc_etype_header(skb, RTL8_4_TAG_LEN); > + tag = dsa_etype_header_pos_tx(skb); > + > + /* Set Realtek EtherType */ > + tag[0] = htons(ETH_P_REALTEK); > + > + /* Set Protocol; zero REASON */ > + tag[1] = htons(RTL8_4_PROTOCOL_RTL8365MB << 8); > + > + /* Zero FID_EN, FID, PRI_EN, PRI, KEEP; set LEARN_DIS */ > + tag[2] = htons(1 << 5); > + > + /* Zero ALLOW; set RX (CPU->switch) forwarding port mask */ > + tag[3] = htons(BIT(dp->index)); > + > + return skb; > +} > + > +static struct sk_buff *rtl8_4_tag_rcv(struct sk_buff *skb, > + struct net_device *dev) > +{ > + __be16 *tag; > + u16 etype; > + u8 proto; > + u8 port; > + > + if (unlikely(!pskb_may_pull(skb, RTL8_4_TAG_LEN))) > + return NULL; > + > + tag = dsa_etype_header_pos_rx(skb); > + > + /* Parse Realtek EtherType */ > + etype = ntohs(tag[0]); > + if (unlikely(etype != ETH_P_REALTEK)) { > + dev_warn_ratelimited(&dev->dev, > + "non-realtek ethertype 0x%04x\n", etype); > + return NULL; > + } > + > + /* Parse Protocol */ > + proto = ntohs(tag[1]) >> 8; > + if (unlikely(proto != RTL8_4_PROTOCOL_RTL8365MB)) { > + dev_warn_ratelimited(&dev->dev, > + "unknown realtek protocol 0x%02x\n", > + proto); > + return NULL; > + } > + > + /* Parse TX (switch->CPU) */ > + port = ntohs(tag[3]) & 0xf; /* Port number is the LSB 4 bits */ > + skb->dev = dsa_master_find_slave(dev, 0, port); > + if (!skb->dev) { > + dev_warn_ratelimited(&dev->dev, > + "could not find slave for port %d\n", > + port); > + return NULL; > + } > + > + /* Remove tag and recalculate checksum */ > + skb_pull_rcsum(skb, RTL8_4_TAG_LEN); > + > + dsa_strip_etype_header(skb, RTL8_4_TAG_LEN); > + > + dsa_default_offload_fwd_mark(skb); > + > + return skb; > +} > + > +static const struct dsa_device_ops rtl8_4_netdev_ops = { > + .name = "rtl8_4", > + .proto = DSA_TAG_PROTO_RTL8_4, > + .xmit = rtl8_4_tag_xmit, > + .rcv = rtl8_4_tag_rcv, > + .needed_headroom = RTL8_4_TAG_LEN, > +}; > +module_dsa_tag_driver(rtl8_4_netdev_ops); > + > +MODULE_LICENSE("GPL"); > +MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_RTL8_4); > -- > 2.32.0 >
On 10/12/21 2:50 PM, Vladimir Oltean wrote: > On Tue, Oct 12, 2021 at 02:35:53PM +0200, Alvin Šipraga wrote: >> From: Alvin Šipraga <alsi@bang-olufsen.dk> >> >> This commit implements a basic version of the 8 byte tag protocol used >> in the Realtek RTL8365MB-VC unmanaged switch, which carries with it a >> protocol version of 0x04. >> >> The implementation itself only handles the parsing of the EtherType >> value and Realtek protocol version, together with the source or >> destination port fields. The rest is left unimplemented for now. >> >> The tag format is described in a confidential document provided to my >> company by Realtek Semiconductor Corp. Permission has been granted by >> the vendor to publish this driver based on that material, together with >> an extract from the document describing the tag format and its fields. >> It is hoped that this will help future implementors who do not have >> access to the material but who wish to extend the functionality of >> drivers for chips which use this protocol. >> >> In addition, two possible values of the REASON field are specified, >> based on experiments on my end. Realtek does not specify what value this >> field can take. >> >> Signed-off-by: Alvin Šipraga <alsi@bang-olufsen.dk> >> --- > > Reviewed-by: Vladimir Oltean <olteanv@gmail.com> > >> RFC -> v1: >> - minor changes to the big comment at the top, including some >> empirical information about the REASON code >> - use dev_*_ratelimited() instead of netdev_*() for logging >> - use warning instead of debug messages >> - use ETH_P_REALTEK from if_ether.h >> - set LEARN_DIS on xmit >> - remove superfluous variables/expressions and use __b16 for tag >> variable >> - use new helper functions to insert/remove CPU tag >> - set offload_fwd_mark properly using helper function >> >> include/net/dsa.h | 2 + >> net/dsa/Kconfig | 6 ++ >> net/dsa/Makefile | 1 + >> net/dsa/tag_rtl8_4.c | 166 +++++++++++++++++++++++++++++++++++++++++++ >> 4 files changed, 175 insertions(+) >> create mode 100644 net/dsa/tag_rtl8_4.c >> >> diff --git a/include/net/dsa.h b/include/net/dsa.h >> index d784e76113b8..783060e851a9 100644 >> --- a/include/net/dsa.h >> +++ b/include/net/dsa.h >> @@ -51,6 +51,7 @@ struct phylink_link_state; >> #define DSA_TAG_PROTO_SEVILLE_VALUE 21 >> #define DSA_TAG_PROTO_BRCM_LEGACY_VALUE 22 >> #define DSA_TAG_PROTO_SJA1110_VALUE 23 >> +#define DSA_TAG_PROTO_RTL8_4_VALUE 24 >> >> enum dsa_tag_protocol { >> DSA_TAG_PROTO_NONE = DSA_TAG_PROTO_NONE_VALUE, >> @@ -77,6 +78,7 @@ enum dsa_tag_protocol { >> DSA_TAG_PROTO_OCELOT_8021Q = DSA_TAG_PROTO_OCELOT_8021Q_VALUE, >> DSA_TAG_PROTO_SEVILLE = DSA_TAG_PROTO_SEVILLE_VALUE, >> DSA_TAG_PROTO_SJA1110 = DSA_TAG_PROTO_SJA1110_VALUE, >> + DSA_TAG_PROTO_RTL8_4 = DSA_TAG_PROTO_RTL8_4_VALUE, >> }; >> >> struct dsa_switch; >> diff --git a/net/dsa/Kconfig b/net/dsa/Kconfig >> index 6c7f79e45886..57fc52b17d55 100644 >> --- a/net/dsa/Kconfig >> +++ b/net/dsa/Kconfig >> @@ -130,6 +130,12 @@ config NET_DSA_TAG_RTL4_A >> Realtek switches with 4 byte protocol A tags, sich as found in >> the Realtek RTL8366RB. >> >> +config NET_DSA_TAG_RTL8_4 >> + tristate "Tag driver for Realtek 8 byte protocol 4 tags" >> + help >> + Say Y or M if you want to enable support for tagging frames for Realtek >> + switches with 8 byte protocol 4 tags, such as the Realtek RTL8365MB-VC. >> + >> config NET_DSA_TAG_LAN9303 >> tristate "Tag driver for SMSC/Microchip LAN9303 family of switches" >> help >> diff --git a/net/dsa/Makefile b/net/dsa/Makefile >> index f78d537044db..9f75820e7c98 100644 >> --- a/net/dsa/Makefile >> +++ b/net/dsa/Makefile >> @@ -16,6 +16,7 @@ obj-$(CONFIG_NET_DSA_TAG_OCELOT) += tag_ocelot.o >> obj-$(CONFIG_NET_DSA_TAG_OCELOT_8021Q) += tag_ocelot_8021q.o >> obj-$(CONFIG_NET_DSA_TAG_QCA) += tag_qca.o >> obj-$(CONFIG_NET_DSA_TAG_RTL4_A) += tag_rtl4_a.o >> +obj-$(CONFIG_NET_DSA_TAG_RTL8_4) += tag_rtl8_4.o >> obj-$(CONFIG_NET_DSA_TAG_SJA1105) += tag_sja1105.o >> obj-$(CONFIG_NET_DSA_TAG_TRAILER) += tag_trailer.o >> obj-$(CONFIG_NET_DSA_TAG_XRS700X) += tag_xrs700x.o >> diff --git a/net/dsa/tag_rtl8_4.c b/net/dsa/tag_rtl8_4.c >> new file mode 100644 >> index 000000000000..da22fd12b645 >> --- /dev/null >> +++ b/net/dsa/tag_rtl8_4.c >> @@ -0,0 +1,166 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +/* >> + * Handler for Realtek 8 byte switch tags >> + * >> + * Copyright (C) 2021 Alvin Šipraga <alsi@bang-olufsen.dk> >> + * >> + * NOTE: Currently only supports protocol "4" found in the RTL8365MB, hence >> + * named tag_rtl8_4. >> + * >> + * This tag header has the following format: >> + * >> + * ------------------------------------------- >> + * | MAC DA | MAC SA | 8 byte tag | Type | ... >> + * ------------------------------------------- >> + * _______________/ \______________________________________ >> + * / \ >> + * 0 7|8 15 >> + * |-----------------------------------+-----------------------------------|--- >> + * | (16-bit) | ^ >> + * | Realtek EtherType [0x8899] | | >> + * |-----------------------------------+-----------------------------------| 8 >> + * | (8-bit) | (8-bit) | >> + * | Protocol [0x04] | REASON | b >> + * |-----------------------------------+-----------------------------------| y >> + * | (1) | (1) | (2) | (1) | (3) | (1) | (1) | (1) | (5) | t >> + * | FID_EN | X | FID | PRI_EN | PRI | KEEP | X | LEARN_DIS | X | e >> + * |-----------------------------------+-----------------------------------| s > > After our previous discussion I thought you said these bits were an EFID_EN and EFID? > Or did you reconsider? No, I did not reconsider - I stand by that observation. I actually sent an email to our contact at Realtek to get some clarification. But until I get a response (not guaranteed) or start actually using the field in the code, I prefer to reproduce their documentation verbatim. > >> + * | (1) | (15-bit) | | >> + * | ALLOW | TX/RX | v >> + * |-----------------------------------+-----------------------------------|--- >> + * >> + * With the following field descriptions: >> + * >> + * field | description >> + * ------------+------------- >> + * Realtek | 0x8899: indicates that this is a proprietary Realtek tag; >> + * EtherType | note that Realtek uses the same EtherType for >> + * | other incompatible tag formats (e.g. tag_rtl4_a.c) >> + * Protocol | 0x04: indicates that this tag conforms to this format >> + * X | reserved >> + * ------------+------------- >> + * REASON | reason for forwarding packet to CPU >> + * | 0: packet was forwarded or flooded to CPU >> + * | 80: packet was trapped to CPU >> + * FID_EN | 1: packet has an FID >> + * | 0: no FID >> + * FID | FID of packet (if FID_EN=1) >> + * PRI_EN | 1: force priority of packet >> + * | 0: don't force priority >> + * PRI | priority of packet (if PRI_EN=1) >> + * KEEP | preserve packet VLAN tag format >> + * LEARN_DIS | don't learn the source MAC address of the packet >> + * ALLOW | 1: treat TX/RX field as an allowance port mask, meaning the >> + * | packet may only be forwarded to ports specified in the >> + * | mask >> + * | 0: no allowance port mask, TX/RX field is the forwarding >> + * | port mask >> + * TX/RX | TX (switch->CPU): port number the packet was received on >> + * | RX (CPU->switch): forwarding port mask (if ALLOW=0) >> + * | allowance port mask (if ALLOW=1) >> + */ >> + >> +#include <linux/bits.h> >> +#include <linux/etherdevice.h> >> + >> +#include "dsa_priv.h" >> + >> +#define RTL8_4_TAG_LEN 8 >> +/* 0x04 = RTL8365MB DSA protocol >> + */ >> +#define RTL8_4_PROTOCOL_RTL8365MB 0x04 >> + >> +static struct sk_buff *rtl8_4_tag_xmit(struct sk_buff *skb, >> + struct net_device *dev) >> +{ >> + struct dsa_port *dp = dsa_slave_to_port(dev); >> + __be16 *tag; >> + >> + /* Pad out so the (stripped) packet is at least 64 bytes long >> + * (including FCS), otherwise the switch will drop the packet. >> + * Then we need an additional 8 bytes for the Realtek tag. >> + */ >> + if (unlikely(__skb_put_padto(skb, ETH_ZLEN + RTL8_4_TAG_LEN, false))) >> + return NULL; >> + >> + skb_push(skb, RTL8_4_TAG_LEN); >> + >> + dsa_alloc_etype_header(skb, RTL8_4_TAG_LEN); >> + tag = dsa_etype_header_pos_tx(skb); >> + >> + /* Set Realtek EtherType */ >> + tag[0] = htons(ETH_P_REALTEK); >> + >> + /* Set Protocol; zero REASON */ >> + tag[1] = htons(RTL8_4_PROTOCOL_RTL8365MB << 8); >> + >> + /* Zero FID_EN, FID, PRI_EN, PRI, KEEP; set LEARN_DIS */ >> + tag[2] = htons(1 << 5); >> + >> + /* Zero ALLOW; set RX (CPU->switch) forwarding port mask */ >> + tag[3] = htons(BIT(dp->index)); >> + >> + return skb; >> +} >> + >> +static struct sk_buff *rtl8_4_tag_rcv(struct sk_buff *skb, >> + struct net_device *dev) >> +{ >> + __be16 *tag; >> + u16 etype; >> + u8 proto; >> + u8 port; >> + >> + if (unlikely(!pskb_may_pull(skb, RTL8_4_TAG_LEN))) >> + return NULL; >> + >> + tag = dsa_etype_header_pos_rx(skb); >> + >> + /* Parse Realtek EtherType */ >> + etype = ntohs(tag[0]); >> + if (unlikely(etype != ETH_P_REALTEK)) { >> + dev_warn_ratelimited(&dev->dev, >> + "non-realtek ethertype 0x%04x\n", etype); >> + return NULL; >> + } >> + >> + /* Parse Protocol */ >> + proto = ntohs(tag[1]) >> 8; >> + if (unlikely(proto != RTL8_4_PROTOCOL_RTL8365MB)) { >> + dev_warn_ratelimited(&dev->dev, >> + "unknown realtek protocol 0x%02x\n", >> + proto); >> + return NULL; >> + } >> + >> + /* Parse TX (switch->CPU) */ >> + port = ntohs(tag[3]) & 0xf; /* Port number is the LSB 4 bits */ >> + skb->dev = dsa_master_find_slave(dev, 0, port); >> + if (!skb->dev) { >> + dev_warn_ratelimited(&dev->dev, >> + "could not find slave for port %d\n", >> + port); >> + return NULL; >> + } >> + >> + /* Remove tag and recalculate checksum */ >> + skb_pull_rcsum(skb, RTL8_4_TAG_LEN); >> + >> + dsa_strip_etype_header(skb, RTL8_4_TAG_LEN); >> + >> + dsa_default_offload_fwd_mark(skb); >> + >> + return skb; >> +} >> + >> +static const struct dsa_device_ops rtl8_4_netdev_ops = { >> + .name = "rtl8_4", >> + .proto = DSA_TAG_PROTO_RTL8_4, >> + .xmit = rtl8_4_tag_xmit, >> + .rcv = rtl8_4_tag_rcv, >> + .needed_headroom = RTL8_4_TAG_LEN, >> +}; >> +module_dsa_tag_driver(rtl8_4_netdev_ops); >> + >> +MODULE_LICENSE("GPL"); >> +MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_RTL8_4); >> -- >> 2.32.0 >>
On Tue, Oct 12, 2021 at 02:35:53PM +0200, Alvin Šipraga wrote: > +static struct sk_buff *rtl8_4_tag_rcv(struct sk_buff *skb, > + struct net_device *dev) > +{ > + __be16 *tag; > + u16 etype; > + u8 proto; > + u8 port; > + > + if (unlikely(!pskb_may_pull(skb, RTL8_4_TAG_LEN))) > + return NULL; > + > + tag = dsa_etype_header_pos_rx(skb); > + > + /* Parse Realtek EtherType */ > + etype = ntohs(tag[0]); > + if (unlikely(etype != ETH_P_REALTEK)) { > + dev_warn_ratelimited(&dev->dev, > + "non-realtek ethertype 0x%04x\n", etype); > + return NULL; > + } > + > + /* Parse Protocol */ > + proto = ntohs(tag[1]) >> 8; > + if (unlikely(proto != RTL8_4_PROTOCOL_RTL8365MB)) { > + dev_warn_ratelimited(&dev->dev, > + "unknown realtek protocol 0x%02x\n", > + proto); > + return NULL; > + } > + > + /* Parse TX (switch->CPU) */ > + port = ntohs(tag[3]) & 0xf; /* Port number is the LSB 4 bits */ > + skb->dev = dsa_master_find_slave(dev, 0, port); > + if (!skb->dev) { > + dev_warn_ratelimited(&dev->dev, > + "could not find slave for port %d\n", > + port); > + return NULL; > + } > + > + /* Remove tag and recalculate checksum */ > + skb_pull_rcsum(skb, RTL8_4_TAG_LEN); > + > + dsa_strip_etype_header(skb, RTL8_4_TAG_LEN); > + > + dsa_default_offload_fwd_mark(skb); This should not be set if the REASON is trapped to CPU. > + > + return skb; > +}
On 10/13/21 11:45 AM, DENG Qingfang wrote: > On Tue, Oct 12, 2021 at 02:35:53PM +0200, Alvin Šipraga wrote: >> +static struct sk_buff *rtl8_4_tag_rcv(struct sk_buff *skb, >> + struct net_device *dev) >> +{ >> + __be16 *tag; >> + u16 etype; >> + u8 proto; >> + u8 port; >> + >> + if (unlikely(!pskb_may_pull(skb, RTL8_4_TAG_LEN))) >> + return NULL; >> + >> + tag = dsa_etype_header_pos_rx(skb); >> + >> + /* Parse Realtek EtherType */ >> + etype = ntohs(tag[0]); >> + if (unlikely(etype != ETH_P_REALTEK)) { >> + dev_warn_ratelimited(&dev->dev, >> + "non-realtek ethertype 0x%04x\n", etype); >> + return NULL; >> + } >> + >> + /* Parse Protocol */ >> + proto = ntohs(tag[1]) >> 8; >> + if (unlikely(proto != RTL8_4_PROTOCOL_RTL8365MB)) { >> + dev_warn_ratelimited(&dev->dev, >> + "unknown realtek protocol 0x%02x\n", >> + proto); >> + return NULL; >> + } >> + >> + /* Parse TX (switch->CPU) */ >> + port = ntohs(tag[3]) & 0xf; /* Port number is the LSB 4 bits */ >> + skb->dev = dsa_master_find_slave(dev, 0, port); >> + if (!skb->dev) { >> + dev_warn_ratelimited(&dev->dev, >> + "could not find slave for port %d\n", >> + port); >> + return NULL; >> + } >> + >> + /* Remove tag and recalculate checksum */ >> + skb_pull_rcsum(skb, RTL8_4_TAG_LEN); >> + >> + dsa_strip_etype_header(skb, RTL8_4_TAG_LEN); >> + >> + dsa_default_offload_fwd_mark(skb); > > This should not be set if the REASON is trapped to CPU. Thanks, you're right. Although with the current state of the driver, skb->offload_fwd_mark will never get set, because the bridge is not offloaded onto the HW. But I will fix this up in v2. > >> + >> + return skb; >> +}
On Tue, Oct 12, 2021 at 2:37 PM Alvin Šipraga <alvin@pqrs.dk> wrote: > From: Alvin Šipraga <alsi@bang-olufsen.dk> > > This commit implements a basic version of the 8 byte tag protocol used > in the Realtek RTL8365MB-VC unmanaged switch, which carries with it a > protocol version of 0x04. > > The implementation itself only handles the parsing of the EtherType > value and Realtek protocol version, together with the source or > destination port fields. The rest is left unimplemented for now. > > The tag format is described in a confidential document provided to my > company by Realtek Semiconductor Corp. Permission has been granted by > the vendor to publish this driver based on that material, together with > an extract from the document describing the tag format and its fields. > It is hoped that this will help future implementors who do not have > access to the material but who wish to extend the functionality of > drivers for chips which use this protocol. > > In addition, two possible values of the REASON field are specified, > based on experiments on my end. Realtek does not specify what value this > field can take. > > Signed-off-by: Alvin Šipraga <alsi@bang-olufsen.dk> The code definately looks good: Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Some nitpicky personal preferences below: > +#define RTL8_4_TAG_LEN 8 > +/* 0x04 = RTL8365MB DSA protocol > + */ > +#define RTL8_4_PROTOCOL_RTL8365MB 0x04 This is #defined > + /* Zero FID_EN, FID, PRI_EN, PRI, KEEP; set LEARN_DIS */ > + tag[2] = htons(1 << 5); I would create defines for the flags like this: #define RTL8365MB_LEARN_DIS BIT(5) > + /* Parse Protocol */ > + proto = ntohs(tag[1]) >> 8; In the 4byte header code we have something like this: #define RTL8_4_PROTOCOL_SHIFT 8 > + /* Parse TX (switch->CPU) */ > + port = ntohs(tag[3]) & 0xf; /* Port number is the LSB 4 bits */ This I think is fair enough. No need to define that mask. Yours, Linus Walleij
diff --git a/include/net/dsa.h b/include/net/dsa.h index d784e76113b8..783060e851a9 100644 --- a/include/net/dsa.h +++ b/include/net/dsa.h @@ -51,6 +51,7 @@ struct phylink_link_state; #define DSA_TAG_PROTO_SEVILLE_VALUE 21 #define DSA_TAG_PROTO_BRCM_LEGACY_VALUE 22 #define DSA_TAG_PROTO_SJA1110_VALUE 23 +#define DSA_TAG_PROTO_RTL8_4_VALUE 24 enum dsa_tag_protocol { DSA_TAG_PROTO_NONE = DSA_TAG_PROTO_NONE_VALUE, @@ -77,6 +78,7 @@ enum dsa_tag_protocol { DSA_TAG_PROTO_OCELOT_8021Q = DSA_TAG_PROTO_OCELOT_8021Q_VALUE, DSA_TAG_PROTO_SEVILLE = DSA_TAG_PROTO_SEVILLE_VALUE, DSA_TAG_PROTO_SJA1110 = DSA_TAG_PROTO_SJA1110_VALUE, + DSA_TAG_PROTO_RTL8_4 = DSA_TAG_PROTO_RTL8_4_VALUE, }; struct dsa_switch; diff --git a/net/dsa/Kconfig b/net/dsa/Kconfig index 6c7f79e45886..57fc52b17d55 100644 --- a/net/dsa/Kconfig +++ b/net/dsa/Kconfig @@ -130,6 +130,12 @@ config NET_DSA_TAG_RTL4_A Realtek switches with 4 byte protocol A tags, sich as found in the Realtek RTL8366RB. +config NET_DSA_TAG_RTL8_4 + tristate "Tag driver for Realtek 8 byte protocol 4 tags" + help + Say Y or M if you want to enable support for tagging frames for Realtek + switches with 8 byte protocol 4 tags, such as the Realtek RTL8365MB-VC. + config NET_DSA_TAG_LAN9303 tristate "Tag driver for SMSC/Microchip LAN9303 family of switches" help diff --git a/net/dsa/Makefile b/net/dsa/Makefile index f78d537044db..9f75820e7c98 100644 --- a/net/dsa/Makefile +++ b/net/dsa/Makefile @@ -16,6 +16,7 @@ obj-$(CONFIG_NET_DSA_TAG_OCELOT) += tag_ocelot.o obj-$(CONFIG_NET_DSA_TAG_OCELOT_8021Q) += tag_ocelot_8021q.o obj-$(CONFIG_NET_DSA_TAG_QCA) += tag_qca.o obj-$(CONFIG_NET_DSA_TAG_RTL4_A) += tag_rtl4_a.o +obj-$(CONFIG_NET_DSA_TAG_RTL8_4) += tag_rtl8_4.o obj-$(CONFIG_NET_DSA_TAG_SJA1105) += tag_sja1105.o obj-$(CONFIG_NET_DSA_TAG_TRAILER) += tag_trailer.o obj-$(CONFIG_NET_DSA_TAG_XRS700X) += tag_xrs700x.o diff --git a/net/dsa/tag_rtl8_4.c b/net/dsa/tag_rtl8_4.c new file mode 100644 index 000000000000..da22fd12b645 --- /dev/null +++ b/net/dsa/tag_rtl8_4.c @@ -0,0 +1,166 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Handler for Realtek 8 byte switch tags + * + * Copyright (C) 2021 Alvin Šipraga <alsi@bang-olufsen.dk> + * + * NOTE: Currently only supports protocol "4" found in the RTL8365MB, hence + * named tag_rtl8_4. + * + * This tag header has the following format: + * + * ------------------------------------------- + * | MAC DA | MAC SA | 8 byte tag | Type | ... + * ------------------------------------------- + * _______________/ \______________________________________ + * / \ + * 0 7|8 15 + * |-----------------------------------+-----------------------------------|--- + * | (16-bit) | ^ + * | Realtek EtherType [0x8899] | | + * |-----------------------------------+-----------------------------------| 8 + * | (8-bit) | (8-bit) | + * | Protocol [0x04] | REASON | b + * |-----------------------------------+-----------------------------------| y + * | (1) | (1) | (2) | (1) | (3) | (1) | (1) | (1) | (5) | t + * | FID_EN | X | FID | PRI_EN | PRI | KEEP | X | LEARN_DIS | X | e + * |-----------------------------------+-----------------------------------| s + * | (1) | (15-bit) | | + * | ALLOW | TX/RX | v + * |-----------------------------------+-----------------------------------|--- + * + * With the following field descriptions: + * + * field | description + * ------------+------------- + * Realtek | 0x8899: indicates that this is a proprietary Realtek tag; + * EtherType | note that Realtek uses the same EtherType for + * | other incompatible tag formats (e.g. tag_rtl4_a.c) + * Protocol | 0x04: indicates that this tag conforms to this format + * X | reserved + * ------------+------------- + * REASON | reason for forwarding packet to CPU + * | 0: packet was forwarded or flooded to CPU + * | 80: packet was trapped to CPU + * FID_EN | 1: packet has an FID + * | 0: no FID + * FID | FID of packet (if FID_EN=1) + * PRI_EN | 1: force priority of packet + * | 0: don't force priority + * PRI | priority of packet (if PRI_EN=1) + * KEEP | preserve packet VLAN tag format + * LEARN_DIS | don't learn the source MAC address of the packet + * ALLOW | 1: treat TX/RX field as an allowance port mask, meaning the + * | packet may only be forwarded to ports specified in the + * | mask + * | 0: no allowance port mask, TX/RX field is the forwarding + * | port mask + * TX/RX | TX (switch->CPU): port number the packet was received on + * | RX (CPU->switch): forwarding port mask (if ALLOW=0) + * | allowance port mask (if ALLOW=1) + */ + +#include <linux/bits.h> +#include <linux/etherdevice.h> + +#include "dsa_priv.h" + +#define RTL8_4_TAG_LEN 8 +/* 0x04 = RTL8365MB DSA protocol + */ +#define RTL8_4_PROTOCOL_RTL8365MB 0x04 + +static struct sk_buff *rtl8_4_tag_xmit(struct sk_buff *skb, + struct net_device *dev) +{ + struct dsa_port *dp = dsa_slave_to_port(dev); + __be16 *tag; + + /* Pad out so the (stripped) packet is at least 64 bytes long + * (including FCS), otherwise the switch will drop the packet. + * Then we need an additional 8 bytes for the Realtek tag. + */ + if (unlikely(__skb_put_padto(skb, ETH_ZLEN + RTL8_4_TAG_LEN, false))) + return NULL; + + skb_push(skb, RTL8_4_TAG_LEN); + + dsa_alloc_etype_header(skb, RTL8_4_TAG_LEN); + tag = dsa_etype_header_pos_tx(skb); + + /* Set Realtek EtherType */ + tag[0] = htons(ETH_P_REALTEK); + + /* Set Protocol; zero REASON */ + tag[1] = htons(RTL8_4_PROTOCOL_RTL8365MB << 8); + + /* Zero FID_EN, FID, PRI_EN, PRI, KEEP; set LEARN_DIS */ + tag[2] = htons(1 << 5); + + /* Zero ALLOW; set RX (CPU->switch) forwarding port mask */ + tag[3] = htons(BIT(dp->index)); + + return skb; +} + +static struct sk_buff *rtl8_4_tag_rcv(struct sk_buff *skb, + struct net_device *dev) +{ + __be16 *tag; + u16 etype; + u8 proto; + u8 port; + + if (unlikely(!pskb_may_pull(skb, RTL8_4_TAG_LEN))) + return NULL; + + tag = dsa_etype_header_pos_rx(skb); + + /* Parse Realtek EtherType */ + etype = ntohs(tag[0]); + if (unlikely(etype != ETH_P_REALTEK)) { + dev_warn_ratelimited(&dev->dev, + "non-realtek ethertype 0x%04x\n", etype); + return NULL; + } + + /* Parse Protocol */ + proto = ntohs(tag[1]) >> 8; + if (unlikely(proto != RTL8_4_PROTOCOL_RTL8365MB)) { + dev_warn_ratelimited(&dev->dev, + "unknown realtek protocol 0x%02x\n", + proto); + return NULL; + } + + /* Parse TX (switch->CPU) */ + port = ntohs(tag[3]) & 0xf; /* Port number is the LSB 4 bits */ + skb->dev = dsa_master_find_slave(dev, 0, port); + if (!skb->dev) { + dev_warn_ratelimited(&dev->dev, + "could not find slave for port %d\n", + port); + return NULL; + } + + /* Remove tag and recalculate checksum */ + skb_pull_rcsum(skb, RTL8_4_TAG_LEN); + + dsa_strip_etype_header(skb, RTL8_4_TAG_LEN); + + dsa_default_offload_fwd_mark(skb); + + return skb; +} + +static const struct dsa_device_ops rtl8_4_netdev_ops = { + .name = "rtl8_4", + .proto = DSA_TAG_PROTO_RTL8_4, + .xmit = rtl8_4_tag_xmit, + .rcv = rtl8_4_tag_rcv, + .needed_headroom = RTL8_4_TAG_LEN, +}; +module_dsa_tag_driver(rtl8_4_netdev_ops); + +MODULE_LICENSE("GPL"); +MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_RTL8_4);